BACKGROUND Intestinal inflammation is a common digestive tract disease, which is usually treated with hormone medicines. Hormone medicines are effective to some extent, but long-term use of them may bring about many c...BACKGROUND Intestinal inflammation is a common digestive tract disease, which is usually treated with hormone medicines. Hormone medicines are effective to some extent, but long-term use of them may bring about many complications.AIM To explore the protective effects of panax notoginseng saponin(PNS) against dextran sulfate sodium(DSS)-induced intestinal inflammatory injury through phosphoinositide-3-kinase protein kinase B(PI3K/AKT) signaling pathway inhibition in rats.METHODS Colitis rat models were generated via DSS induction, and rats were divided into control(no modeling), DSS, DSS + PNS 50 mg/k, and DSS + PNS 100 mg/kg groups. Then, the intestinal injury, oxidative stress parameters, inflammatory indices, tight junction proteins, apoptosis, macrophage polarization, and TLR4/AKT signaling pathway in colon tissues from rats in each of the groups were detected. The PI3 K/AKT signaling pathway in the colon tissue of rats was blocked using the PI3K/AKT signaling pathway inhibitor, LY294002.RESULTS Compared with rats in the control group, rats in the DSS group showed significantly shortened colon lengths, and significantly increased disease activity indices, oxidative stress reactions and inflammatory indices, as well as significantly decreased expression of tight junction-associated proteins. In addition, the DSS group showed significantly increased apoptotic cell numbers,and showed significantly increased M1 macrophages in spleen and colon tissues.They also showed significantly decreased M2 macrophages in colon tissues, as well as activation of the PI3K/AKT signaling pathway(all P < 0.05). Compared with rats in the DSS group, rats in the DSS + PNS group showed significantly lengthened colon lengths, decreased disease activity indices, and significantly alleviated oxidative stress reactions and inflammatory responses. In addition, this group showed significantly increased expression of tight junction-associated proteins, significantly decreased apoptotic cell numbers, and significantly decreased M1 macrophages in spleen and colon tissues. This group further showed significantly increased M2 macrophages in colon tissues, and significantly suppressed activation of the PI3K/AKT signaling pathway, as well as a dose dependency(all P < 0.05). When the PI3K/AKT signaling pathway was inhibited, the apoptosis rate of colon tissue cells in the DSS + LY294002 group was significantly lower than that of the DSS group(P < 0.05).CONCLUSION PNS can protect rats against DSS-induced intestinal inflammatory injury by inhibiting the PI3K/AKT signaling pathway, and therefore may be potentially used in the future as a drug for colitis.展开更多
BACKGROUND The phosphoinositide 3-kinase/protein kinase-B/mechanistic target of rapamycin(PI3K/Akt/mTOR) signalling pathway is crucial for cell survival, differentiation, apoptosis and metabolism. Xihuang pills(XHP) a...BACKGROUND The phosphoinositide 3-kinase/protein kinase-B/mechanistic target of rapamycin(PI3K/Akt/mTOR) signalling pathway is crucial for cell survival, differentiation, apoptosis and metabolism. Xihuang pills(XHP) are a traditional Chinese preparation with antitumour properties. They inhibit the growth of breast cancer, glioma, and other tumours by regulating the PI3K/Akt/mTOR signalling pathway. However, the effects and mechanisms of action of XHP in hepatocellular carcinoma(HCC) remain unclear. Regulation of the PI3K/Akt/mTOR signalling pathway effectively inhibits the progression of HCC. However, no study has focused on the XHPassociated PI3K/Akt/mTOR signalling pathway. Therefore, we hypothesized that XHP might play a role in inhibiting HCC through the PI3K/Akt/mTOR signalling pathway.AIM To confirm the effect of XHP on HCC and the possible mechanisms involved.METHODS The chemical constituents and active components of XHP were analysed using ultra-performance liquid chromatography-quadrupole time of flight mass spectrometry(UPLC-Q-TOF-MS). Cellbased experiments and in vivo xenograft tumour experiments were utilized to evaluate the effect of XHP on HCC tumorigenesis. First, SMMC-7721 cells were incubated with different concentrations of XHP(0, 0.3125, 0.625, 1.25, and 2.5 mg/mL) for 12 h, 24 h and 48 h. Cell viability was assessed using the CCK-8 assay, followed by an assessment of cell migration using a wound healing assay.Second, the effect of XHP on the apoptosis of SMMC-7721 cells was evaluated. SMMC-7721 cells were stained with fluorescein isothiocyanate and annexin V/propidium iodide. The number of apoptotic cells and cell cycle distribution were measured using flow cytometry. The cleaved protein and mRNA expression levels of caspase-3 and caspase-9 were detected using Western blotting and quantitative reverse-transcription polymerase chain reaction(RT-qPCR), respectively.Third, Western blotting and RT–qPCR were performed to confirm the effects of XHP on the protein and mRNA expression of components of the PI3K/Akt/mTOR signalling pathway.Finally, the effects of XHP on the tumorigenesis of subcutaneous hepatocellular tumours in nude mice were assessed.RESULTS The following 12 compounds were identified in XHP using high-resolution mass spectrometry:Valine, 4-gingerol, myrrhone, ricinoleic acid, glycocholic acid, curzerenone, 11-keto-β-boswellic acid, oleic acid, germacrone, 3-acetyl-9,11-dehydro-β-boswellic acid, 5β-androstane-3,17-dione, and 3-acetyl-11-keto-β-boswellic acid. The cell viability assay results showed that treatment with 0.625mg/mL XHP extract decreased HCC cell viability after 12 h, and the effects were dose-and timedependent. The results of the cell scratch assay showed that the migration of HCC cells was significantly inhibited in a time-dependent manner by the administration of XHP extract(0.625mg/mL). Moreover, XHP significantly inhibited cell migration and resulted in cell cycle arrest and apoptosis. Furthermore, XHP downregulated the PI3K/Akt/mTOR signalling pathway, which activated apoptosis executioner proteins(e.g., caspase-9 and caspase-3). The inhibitory effects of XHP on HCC cell growth were determined in vivo by analysing the tumour xenograft volumes and weights.CONCLUSION XHP inhibited HCC cell growth and migration by stimulating apoptosis via the downregulation of the PI3K/Akt/mTOR signalling pathway, followed by the activation of caspase-9 and caspase-3.Our findings clarified that the antitumour effects of XHP on HCC cells are mediated by the PI3K/Akt/mTOR signalling pathway, revealing that XHP may be a potential complementary therapy for HCC.展开更多
Objective: The mechanisms by which lipopolysaccharide (LPS) pretreatment induces cardioprotection following ischaemia/reperfusion (I/R) have not been fully elucidated. We hypothesized that activation of phosphoin...Objective: The mechanisms by which lipopolysaccharide (LPS) pretreatment induces cardioprotection following ischaemia/reperfusion (I/R) have not been fully elucidated. We hypothesized that activation of phosphoinositide 3-kinase (PI3K)/Akt and high mobility group box 1 (HMGBxl) signaling plays an important role in LPS-induced cardioprotection. Methods: In in vivo experiments, age- and weight- matched male C57BL/10Sc wild type mice were pretreated with LPS before ligation of the left anterior descending coronary followed by reperfusion. Infarction size was examined by triphenyltetrazolium chloride (TTC) staining. Akt, phospho-Akt, and HMGBxl were assessed by immunoblotting with appropriate primary antibodies. In situ cardiac myocyte apop- tosis was examined by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. In an in vitro study, rat cardiac myoblasts (H9c2) were subdivided into two groups, and only one was pretreated with LPS. After pretreatment, the cells were transferred into a hypoxic chamber under 0.5% 02. Levels of HMGBxl were assessed by immunoblot. Results: In the in vivo experiment, pretreatment with LPS reduced the at risk infarct size by 70.6% and the left ventricle infarct size by 64.93% respectively. Pretreatment with LPS also reduced cardiac myocytes apoptosis by 39.1% after ischemia and reperfusion. The mechanisms of LPS induced cardioprotection involved increasing PI3K/Akt activity and decreasing expression of HMGBxl. In the in vitro study, pretreatment with LPS reduced the level of HMGBxl in H9c2 cell cytoplasm following hypoxia. Conclusion: The results suggest that the cardioprotection following I/R induced by LPS pretreatment involves PI3K/Akt and HMGBxl pathways.展开更多
BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors.Osteopontin(OPN)is thought to be closely related to the occurrence,metastasis and prognosis of many types of tumors.AIM To investigate the effect...BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors.Osteopontin(OPN)is thought to be closely related to the occurrence,metastasis and prognosis of many types of tumors.AIM To investigate the effects of OPN on the proliferation,invasion and migration of GC cells and its possible mechanism.METHODS The mRNA and protein expression of OPN in the GC cells were analyzed by realtime quantitative-reverse transcription polymerase chain reaction and western blotting,and observe the effect of varying degree expression OPN on the proliferation and other behaviors of GC.Next,the effects of OPN knockdown on GC cells migration and invasion were examined.The short hairpin RNA(shRNA)and negative control shRNA targeting OPN-shRNA were transfected into the cells according to the manufacturer’s instructions.Non transfected cells were classified as control in the identical transfecting process.24 h after RNA transfection cell proliferation activity was detected by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide assay,and cell invasiveness and migration were detected by Trans well assay.Meanwhile,the expression of protein kinase B(AKT),matrix metalloproteinase 2(MMP-2)and vascular endothelial growth factor(VEGF)in the human GC cell lines was detected by reverse transcription polymerase chain reaction and western blotting.RESULTS The results of this study revealed that OPN mRNA and protein expression levels were highly expressed in SGC-7901 cells.OPN knockdown by specific shRNA noticeably reduced the capabilities of proliferation,invasion and migration of SGC-7901 cells.Moreover,in the experiments of investigating the underlying mechanism,results showed that OPN knockdown could down-regulated the expression of MMP-2 and VEGF,it also decreased the phosphorylation of AKT.Meanwhile,the protein expression levels of MMP-2,VEGF and phosphorylated AKT was noticeable lower than that in control group in the GC cells after they were added to phosphatidylinositol-3-kinase(PI3K)inhibitor(LY294002).CONCLUSION These results suggested that OPN though PI3K/AKT/mammalian target of rapamycin signal pathway to upregulate MMP-2 and VEGF expression,which contribute SGC-7901 cells to proliferation,invasion and migration.Thus,our results demonstrate that OPN may serve as a novel prognostic biomarkers as well as a potential therapeutic targets for GC.展开更多
A large body of experimental and clinical data supports the notion that inflammation in acute pancreatitis has a crucial role in the pathogenesis of local and systemic damage and is a major determinant of clinical sev...A large body of experimental and clinical data supports the notion that inflammation in acute pancreatitis has a crucial role in the pathogenesis of local and systemic damage and is a major determinant of clinical severity. Thus, research has recently focused on molecules that can regulate the inflammatory processes, such as phosphoinositide 3-kinases (PI3Ks), a family of lipid and protein kinases involved in intracellular signal transduction. Studies using genetic ablation or pharmacologic inhibitors of different PI3K isoforms, in particular the class I PI3Kδ and PI3Kγ, have contributed to a greater understanding of the roles of these kinases in the modulation of inflammatory and immune responses. Recent data suggest that PI3Ks are also involved in the pathogenesis of acute pancreatitis. Activation of the PI3K signaling pathway, and in particular of the class IB PI3Kγ isoform, has a significant role in those events which are necessary for the initiation of acute pancreatic injury, namely calcium signaling alteration, trypsinogen activation, and nuclear factor-κB transcription. Moreover, PI3Kγ is instrumental in modulating acinar cell apoptosis, and regulating local neutrophil infiltration and systemic inflammatory responses during the course of experimental acute pancreatitis. The availability of PI3K inhibitors selective for specific isoforms may provide new valuable therapeutic strategies to improve the clinical course of this disease. This article presents a brief summary of PI3K structure and function, and highlights recent advances that implicate PI3Ks in the pathogenesis of acute pancreatitis.展开更多
To investigate the molecular mechanism of leptin regulating insulin secretion through determining the regulation of insulin secretion and the insulin receptor substrate (IRS)-2-associated phosphoinositide 3-kinase (PI...To investigate the molecular mechanism of leptin regulating insulin secretion through determining the regulation of insulin secretion and the insulin receptor substrate (IRS)-2-associated phosphoinositide 3-kinase (PI3K) activity by leptin in the isolated rat pancreatic islets, pancreatic islets were isolated from male SD rats by the collagenase method. The purified islets were incubated with leptin 2 nmol/L for 1 h in the presence of 5.6 mmol/L or 11.1 mmol/L glucose. Insulin release was measured using radioimmunoassay. IRS-2-associated activity of PI3K was determined by immunoprecipitate assay and Western blot. The results showed that in the presence of 5.6 mmol/L glucose, leptin had no significant effect on both insulin secretion and IRS-2-associated PI3K activity, but in the presence of 11.1 mmol/L glucose, insulin release was significantly inhibited after the islets were exposed to leptin for 1 h (P<0.01). PI3K inhibitor wortmannin blocked the inhibitory regulation of leptin on insulin release (P<0.05). Western Blot assay revealed that 2 nmol/L leptin could significantly increase the IRS-2-associated activity of PI3K by 51.5 % (P<0.05) in the presence of 11.1 mmol/L glucose. It was concluded that Leptin could significantly inhibit insulin secretion in the presence of 11.1 mmol/L glucose by stimulating IRS-2-associated activity of PI3K, which might be the molecular mechanism of leptin regulating insulin secretion.展开更多
[Objectives]To explore the protective effects of Zuogui Pill on ^(60)Co-γ-ray-induced premature aging of rats based on phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR)signal...[Objectives]To explore the protective effects of Zuogui Pill on ^(60)Co-γ-ray-induced premature aging of rats based on phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR)signaling pathway.[Methods]Sixty sexually mature female SD rats were irradiated with ^(60)Co-γ-ray(6.0 Gy,LD 40)for 24 h at one time.These rats were randomly divided into model group,Progynova group[0.18(g·kg)/d],Progynova[0.09(g·kg)/d]+Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill medium dose[9.45(g·kg)/d)]group and Zuogui Pill low dose[4.725(g·kg)/d]group.The administration(once a day)lasted 21 d.The rat serum[follicle-stimulating hormone(FSH),luteinizing hormone(LH)and estradiol(E_(2))]were detected by Enzyme-linked immunosorbent assay(ELISA).The morphological changes of ovary were observed by hematoxylin-eosin(HE)staining.The apoptosis rate of granulosa cells was detected by terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling(TUNEL).The protein expression of phosphorylated(p)-PI3K,p-Akt,p-mTOR,B-cell lymphoma-2(Bcl-2),and Bcl-2-associated X protein(Bax)in ovarian tissues were detected by Western blot.[Results]Compared with the normal group,the model group showed significant increase in the serum FSH(P<0.01),significant decrease in serum E_(2)(P<0.05),and decrease in the number of early follicles and luteum in the ovary(P<0.01).Besides,the apoptosis rate of granulosa cells increased significantly(P<0.01);the expression of p-PI3K,p-Akt,p-mTOR and Bcl-2 in ovarian tissue decreased significantly,while the expression of Bax increased significantly(P<0.01).Compared with the model group,the number of early follicles in the ovary increased and the apoptosis rate of granulosa cells decreased after intervention in each administration group.In addition,the protein expressions of p-PI3K,p-Akt,p-mTOR and Bcl-2 increased,while the expression of Bax decreased,especially in Progynova+Zuogui Pill high dose group,the differences were statistically significant(P<0.05,P<0.01).[Conclusions]Zuogui Pill may protect the radiation-injured ovary through activating the expression of PI3K/Akt/mTOR protein in ovarian tissue,increasing the amount of Bcl-2 protein and inhibiting the expression of Bax protein.展开更多
AIM:To determine whether mitochondrial dysfunction resulting from high-fat diet is related to impairment of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt,also known as PKB) pathway. METHODS:Rat models...AIM:To determine whether mitochondrial dysfunction resulting from high-fat diet is related to impairment of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt,also known as PKB) pathway. METHODS:Rat models of nonalcoholic fatty liver were established by high-fat diet feeding. The expression of total and phosphorylated P13K and Akt proteins in hepatocytes was determined by Western blotting. Degree of fat accumulation in liver was measured by hepatic triglyceride. Mitochondrial number and size were determined using quantitative morphometric analysis under transmission electron microscope. The permeability of the outer mitochondrial membrane was assessed by determining the potential gradient across this membrane.RESULTS:After Wistar rats were fed with high-fat diet for 16 wk,their hepatocytes displayed an accumulation of fat (103.1 ± 12.6 vs 421.5 ± 19.7,P < 0.01),deformed mitochondria (9.0% ± 4.3% vs 83.0% ± 10.9%,P < 0.05),and a reduction in the mitochondrial membrane potential (389.385% ± 18.612% vs 249.121% ± 13.526%,P < 0.05). In addition,the expression of the phosphorylated P13K and Akt proteins in hepatocytes was reduced,as was the expression of the anti-apoptotic protein Bcl-2,while expression of the pro-apoptotic protein caspase-3 was increased. When animals were treated with pharmacological inhibitors of P13K or Akt,instead of high-fat diet,a similar pattern of hepatocellular fat accumulation,mitochondrial impairment,and change in the levels of PI3K,Akt,Bcl-2 was observed. CONCLUSION:High-fat diet appears to inhibit the PI3K/Akt signaling pathway,which may lead to hepa-tocellular injury through activation of the mitochondrial membrane pathway of apoptosis.展开更多
Background: Autophagy of alveolar macrophages is a crucial process in ischemia/reperfusion injury-induced acute lung injury (ALI). Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent cells with the po...Background: Autophagy of alveolar macrophages is a crucial process in ischemia/reperfusion injury-induced acute lung injury (ALI). Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent cells with the potential for repairing injured sites and regulating autophagy. This study was to investigate the influence of BM-MSCs on autophagy of macrophages in the oxygen-glucose deprivation/restoration (OGD/R) microenvironment and to explore the potential mechanism.Methods: We established a co-culture system of macrophages (RAW264.7) with BM-MSCs under OGD/R conditionsin vitro. RAW264.7 cells were transfected with recombinant adenovirus (Ad-mCherry-GFP-LC3B) and autophagic status of RAW264.7 cells was observed under a fluorescence microscope. Autophagy-related proteins light chain 3 (LC3)-I, LC3-II, and p62 in RAW264.7 cells were detected by Western blotting. We used microarray expression analysis to identify the differently expressed genes between OGD/R treated macrophages and macrophages co-culture with BM-MSCs. We investigated the gene heme oxygenase-1 (HO-1), which is downstream of the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway.Results: The ratio of LC3-II/LC3-I of OGD/R treated RAW264.7 cells was increased (1.27 ± 0.20vs. 0.44 ± 0.08,t = 6.67,P < 0.05), while the expression of p62 was decreased (0.77 ± 0.04vs. 0.95 ± 0.10,t = 2.90,P < 0.05), and PI3K (0.40 ± 0.06vs. 0.63 ± 0.10,t = 3.42,P < 0.05) and p-Akt/Akt ratio was also decreased (0.39 ± 0.02vs. 0.58 ± 0.03,t = 9.13,P < 0.05). BM-MSCs reduced the LC3-II/LC3-I ratio of OGD/R treated RAW264.7 cells (0.68 ± 0.14vs. 1.27 ± 0.20,t = 4.12,P < 0.05), up-regulated p62 expression (1.10 ± 0.20vs. 0.77 ± 0.04,t = 2.80,P < 0.05), and up-regulated PI3K (0.54 ± 0.05vs. 0.40 ± 0.06,t = 3.11,P < 0.05) and p-Akt/Akt ratios (0.52 ± 0.05vs. 0.39 ± 0.02,t = 9.13,P < 0.05). A whole-genome microarray assay screened the differentially expressed geneHO-1, which is downstream of the PI3K/Akt signaling pathway, and the alteration ofHO-1 mRNA and protein expression was consistent with the data on PI3K/Akt pathway.Conclusions: Our results suggest the existence of the PI3K/Akt/HO-1 signaling pathway in RAW264.7 cells under OGD/R circumstancesin vitro, revealing the mechanism underlying BM-MSC-mediated regulation of autophagy and enriching the understanding of potential therapeutic targets for the treatment of ALI.展开更多
Tongluojiunao (TLJN) is an herbal medicine consisting of two main components, geniposide and ginsenoside Rg1. TLJN has been shown to protect primary cultured hippocampal neurons. How-ever, its mechanism of action re...Tongluojiunao (TLJN) is an herbal medicine consisting of two main components, geniposide and ginsenoside Rg1. TLJN has been shown to protect primary cultured hippocampal neurons. How-ever, its mechanism of action remains unclear. In the present study, primary cultured hippocampal neurons treated with Aβ1-42 (10 μmol/L) signiifcantly increased the release of lactate dehydroge-nase, which was markedly reduced by TLJN (2 μL/mL), speciifcally by the component geniposide (26 μmol/L), but not ginsenoside Rg1 (2.5 μmol/L). hTe estrogen receptor inhibitor, ICI182780 (1 μmol/L), did not block TLJN-or geniposide-mediated decrease of lactate dehydrogenase under Aβ1-42-exposed conditions. However, the phosphatidyl inositol 3-kinase or mitogen-activated protein kinase pathway inhibitor, LY294002 (50 μmol/L) or U0126 (10 μmol/L), respectively blo cked the decrease of lactate dehydrogenase mediated by TLJN or geniposide. hTerefore, these results suggest that the non-classical estrogen pathway (i.e., phosphatidyl inositol 3-kinase or mitogen-activated protein kinase) is involved in the neuroprotective effect of TLJN, speciifcally its component, geniposide, against Aβ1-42-mediated cell death in primary cultured hippocampal neurons.展开更多
The study was conducted to investigate the effect and mechanism of dietary quercetin supplementation on protein utilization of Arbor Acres(AA)broilers.A total of 2401-day-old AA broilers were randomly allocated to fou...The study was conducted to investigate the effect and mechanism of dietary quercetin supplementation on protein utilization of Arbor Acres(AA)broilers.A total of 2401-day-old AA broilers were randomly allocated to four treatments with six replicates,comprising 10 broilers each replicate(60 broilers per treatment).Birds were fed either a corn-soybean meal basal diet without quercetin(control)or a basal diet supplemented with 0.2,0.4 or 0.6 g of quercetin per kg feed,and the trial lasted 42 days.Dietary quercetin supplementation tended to increase the apparent metabolic rate of protein(p=0.076)and the content of serum albumin(p=0.062)in AA broilers.Compared with the control,dietary quercetin supplementation increased the contents of protein in breast muscle(p<0.05)and in thigh muscle(p=0.053).In addition,quercetin up-regulated mRNA expression of insulin-like growth factor 1(IGF-1),phosphatidylinositol 3-kinase(PI3K),target of rapamycin(TOR),ribosomal protein S6 kinase 1(S6K1),eukaryotic translation initiation factor 4E(eIF4E),eukaryotic translation initiation factor 4G(eIF4G),eukaryotic elongation factor 2(eEF2)and eukaryotic translation initiation factor 4B(eIF4B)genes and down-regulated mRNA expression of eukaryotic elongation factor 2 kinase(eEF2K)and eukaryotic initiation factor 4E binding protein1(4E-BP1)genes in breast muscle,thigh muscle and liver of AA broilers(p<0.05).The present results suggested that dietary quercetin supplementation enhanced protein utilization in broilers by activating TOR signaling pathway.展开更多
Background: Nucleoside reverse transcriptase inhibitors (NRTIs) are the earliest and most commonly used anti-human immunodeficiency virus drugs and play an important role in high active antiretroviral therapy. Howe...Background: Nucleoside reverse transcriptase inhibitors (NRTIs) are the earliest and most commonly used anti-human immunodeficiency virus drugs and play an important role in high active antiretroviral therapy. However, NRTI drug therapy can cause peripheral neuropathic pain. In this study, we aimed to investigate the mechanisms ofrapamycin on the pain sensitization of model mice by in vivo experiments to explore the effect of mammalian target of rapamycin (mTOR) in the pathogenesis ofneuropathic pain caused by NRTIs. Methods: Male Kun Ming (KM) mice weighing 20-2 g were divided into control, 2 mg/kg rapamycin, 12 mg/kg stavudine, and CMC-Na groups. Drugs were orally administered to mice for 42 consecutive days. The von Frey filament detection and thermal pain tests were conducted on day 7, 14, 21, 28, 35, and 42 after drug administration. After the last behavioral tests, immunohistochemistry and western blotting assay were used for the measurement of mTOR and other biomarkers. Multivariate analysis of variance was used. Results: The beneficial effects ofrapamycin on neuropathic pain were attributed to a reduction in mammalian target of rapamycin sensitive complex 1 (mTORC1)-positive cells (70.80± 2.41 vs. 112.30 ± 5.66, F = 34.36, P 〈 0.01 ) and mTORC1 activity in the mouse spinal cord. Mechanistic studies revealed that Protein Kinase B (Akt)/mTOR signaling pathway blockade with rapamycin prevented the phosphorylation of mTORC1 in stavudine-intoxicated mice (0.72 ± 0.04 vs. 0.86 ± 0.03, F=4.24, P = 0.045), as well as decreased the expression of phospho-pTOS6K (0.47 ± 0.01 vs. 0.68 ± 0.03, F=6.01, P = 0.022) and phospho-4EBP1 (0.90 ± 0.04 vs. 0.94 ± 0.06, F= 0.28, P = 0.646). Conclusions: Taken together, these results suggest that stavudine elevates the expression and activity of mTORC1 in the spinal cord through activating the Akt/mTOR signaling pathway. The data also provide evidence that rapamycin might be useful for the treatment of peripheral neuropathic pain.展开更多
Objective:To investigate whether Buthus martensii karsch(Scorpiones),Scolopendra subspinipes mutilans L.Koch(Scolopendra)and Gekko gecko Linnaeus(Gekko)could ameliorate the hypoxic tumor microenvironment and inhibit l...Objective:To investigate whether Buthus martensii karsch(Scorpiones),Scolopendra subspinipes mutilans L.Koch(Scolopendra)and Gekko gecko Linnaeus(Gekko)could ameliorate the hypoxic tumor microenvironment and inhibit lung cancer growth and metastasis by regulating phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin/hypoxia-inducible factor-1α(PI3K/AKT/mTOR/HIF-1α)signaling pathway.Methods:Male C57BL/6J mice were inoculated with luciferase labeled LL/2-luc-M38 cell suspension to develop lung cancer models,with rapamycin and cyclophosphamide as positive controls.Carboxy methyl cellulose solutions of Scorpiones,Scolopendra and Gekko were administered intragastrically as 0.33,0.33,and 0.83 g/kg,respectively once daily for 21 days.Fluorescent expression were detected every 7 days after inoculation,and tumor growth curves were plotted.Immunohistochemistry was performed to determine CD31 and HIF-1αexpressions in tumor tissue and microvessel density(MVD)was analyzed.Western blot was performed to detect the expression of PI3K/AKT/mTOR/HIF-1αsignaling pathway-related proteins.Enzyme-linked immunosorbent assay was performed to detect serum basic fibroblast growth factor(bFGF),transforming growth factor-β1(TGF-β1)and vascular endothelial growth factor(VEGF)in mice.Results:Scorpiones,Scolopendra and Gekko prolonged the survival time and inhibited lung cancer metastasis and expression of HIF-1α(all P<0.01).Moreover,Scorpiones,Scolopendra and Gekko inhibited the phosphorylation of AKT and ribosomal protein S6 kinase(p70S6K)(P<0.05 or P<0.01).In addition,they also decreased the expression of CD31,MVD,bFGF,TGF-β1 and VEGF compared with the model group(P<0.05 or P<0.01).Conclusion:Scorpiones,Scolopendra and Gekko all showed beneficial effects on lung cancer by ameliorating the hypoxic tumor microenvironment via PI3K/AKT/mTOR/HIF-1αsignaling pathway.展开更多
The phosphosphatidylinositol-3-kinase(PI3K)signaling pathway is one of the most important intracellular signal transduction pathways affecting cell functions,such as apoptosis,translation,metabolism,and angiogenesis.L...The phosphosphatidylinositol-3-kinase(PI3K)signaling pathway is one of the most important intracellular signal transduction pathways affecting cell functions,such as apoptosis,translation,metabolism,and angiogenesis.Lung cancer is a malignant tumor with the highest morbidity and mortality rates in the world.It can be divided into two groups,non-small cell lung cancer(NSCLC)and small cell lung cancer(SCLC).NSCLC accounts for>85%of all lung cancers.There are currently many clinical treatment options for NSCLC;however,traditional methods such as surgery,chemotherapy,and radiotherapy have not been able to provide patients with good survival benefits.The emergence of molecular target therapy has improved the survival and prognosis of patients with NSCLC.In recent years,there have been an increasing number of studies on NSCLC and PI3K signaling pathways.Inhibitors of various parts of the PI3K pathway have appeared in various phases of clinical trials with NSCLC as an indication.This article focuses on the role of the PI3K signaling pathway in the occurrence and development of NSCLC and summarizes the current clinical research progress and possible development strategies.展开更多
Objective:To investigate the hemostatic effect of modified Sijunzi Granules(MSG)in primary immune thrombocytopenia(ITP)zebrafish model and explore the potential mechanism.Methods:AB strain wild type zebrafish were tre...Objective:To investigate the hemostatic effect of modified Sijunzi Granules(MSG)in primary immune thrombocytopenia(ITP)zebrafish model and explore the potential mechanism.Methods:AB strain wild type zebrafish were treated with simvastatin(6μmol/L)for 24 h to establish the hemorrhage model(model control group).The zebrafish were treated with MSG at different doses(55.6,167,and 500μg/mL),respectively.The hemostatic effect was assessed by examining the intestinal bleeding and hemostatic rate.5-hydroxytryptamine(5-HT)content was determined using enzyme-linked immunosorbent assay(ELISA)assay.The expressions of5-HT2aR,5-HT2bR,and SERT genes were detected by quantitative real-time polymerase chain reaction(PCR).The protein expressions of protein kinase B(Akt),p-Akt,extracellular regulated protein kinases(Erk),and p-Erk were examined using Western blot analysis.Results:The intestinal bleeding rate was 37%,40%,and 80%in the55.6,167,and 500μg/mL dose of MSG,respectively,in which 55.6 and 167μg/mL MSG dose groups were associated with significantly decreased intestinal bleeding rate when compared with the model control group(70%,P<0.05).Significantly higher hemostatic rates were also observed in the 55.6μg/mL(54%)and 167μg/mL(52%)MSG dose groups(P<0.05).MSG increased the 5-HT content and mRNA expression levels of 5-HT2aR,5-HT2bR,and SERT(P<0.05).In addition,caspase3/7 activity was inhibited(P<0.05).Significant increase in p-Akt and p-Erk was also detected after treatment with MSG(P<0.05).Conclusions:MSG could reduce the incidence and severity of intestinal bleeding in zebrafish by activating MAPK/Erk and PI3K/Akt signal pathways through regulating the levels of 5-HT and its receptors,which may provide evidence for the treatment of ITP.展开更多
BACKGROUND In China banxia xiexin decoction(BXD)has been used in treating gastric cancer(GC)for thousands of years and BXD has a good role in reversing GC histopathology,but its chemical composition and action mechani...BACKGROUND In China banxia xiexin decoction(BXD)has been used in treating gastric cancer(GC)for thousands of years and BXD has a good role in reversing GC histopathology,but its chemical composition and action mechanism are still unknown.AIM To investigate the mechanism of action of BXD against GC based on transcriptomics,network pharmacology,in vivo and in vitro experiments.METHODS The transplanted tumor model was prepared,and the nude mouse were pathologically examined after administration,and hematoxylin-eosin staining was performed.The active ingredients of BXD were quality controlled and identified using ultra-performance liquid chromatography tandem quadrupole electrostatic field orbitrap mass spectrometry(UPLC-Q-Orbitrap MS/MS),and traditional Chinese medicines systems pharmacology platform,drug bank and the Swiss target prediction platform to predict the relevant targets,the differentially expressed genes(DEGs)of GC were screened by RNA-seq sequencing,and the overlapping targets were analyzed to obtain the key targets and pathways.Cell Counting Kit-8,apoptosis assay,cell migration and Realtime fluorescence quantitative polymerase chain reaction were used for in vitro experiments.RESULTS All dosing groups inhibited the growth of transplanted tumors in laboratory-bred strain nude,with the capecitabine group and the BXD medium-dose group being the best.A total of 29 compounds and 859 potential targets in BXD were identified by UPLC-Q-Orbitrap MS/MS and network pharmacology,RNA-seq sequencing found 4767 GC DEGs,which were combined with network pharmacology and analyzed 246 potential therapeutic targets were obtained and pathway results showed that BXD may against GC through the Phosphoinositide 3-kinase(PI3K)/protein kinase B(AKt)signaling pathway.In vitro cellular experiments confirmed that BXDcontaining serum and LY294002 could inhibit the proliferation of GC cells,promote apoptosis,and inhibit the migration of GC cells by decreasing the expression of EGFR,PIK3CA,IL6,BCL2 and AKT1 in the PI3K-Akt pathway in MGC-803 expression.CONCLUSION BXD has the effect of inhibiting tumor growth rate and delaying the development of GC.Its mechanism of action may be related to the regulation of PI3K-Akt signaling pathway.展开更多
Pancreatic cancer is a highly aggressive tumour that is very resistant to treatments and it is rarely diagnosed early because of absence of specific symptoms. Therefore, the prognosis for this disease is very poor and...Pancreatic cancer is a highly aggressive tumour that is very resistant to treatments and it is rarely diagnosed early because of absence of specific symptoms. Therefore, the prognosis for this disease is very poor and it has the grim supremacy in terms of unfavourable survival rates. There have been great advances in survival rates for many types of cancers over the past few decades but hardly any change for pancreatic cancer. Mutations of the Ras oncogene are the most frequent oncogenic alterations in human cancers. The frequency of KRAS mutations in pancreatic cancer is around 90%. Given the well-established role of KRAS in cancer it is not surprising that it is one of the most attractive targets for cancer therapy. Nevertheless, during the last thirty years all attempts to target directly KRAS protein have failed. Therefore, it is crucial to identify downstream KRAS effectors in order to develop specific drugs able to counteract activation of this pathway. Among the different signalling pathways activated by oncogenic KRAS, the phosphoinositide 3-Kinase(PI3K) pathway is emerging as one of the most critical KRAS effector. In turn, PI3 K activates several parallel pathways making the identification of the precise effectors activated by KRAS/PI3 K more difficult. Recent data identify 3-phosphoinositide-dependent protein kinase 1 as a key tumour-initiating event downstream KRAS interaction with PI3 K in pancreatic cancer.展开更多
The APPswe plasmid was transfected into the neuroblastoma cell line SH-SY5Y to establish a cell model of Alzheimer's disease. Graded concentration and time course experiments demonstrate that curcumin significantly u...The APPswe plasmid was transfected into the neuroblastoma cell line SH-SY5Y to establish a cell model of Alzheimer's disease. Graded concentration and time course experiments demonstrate that curcumin significantly upregulates phosphatidylinositol 3-kinase (PI3K), Akt, nuclear factor E2-related factor-2 (Nrf2), heme oxygenase 1 and ferritin expression, and that it significantly downregulates heme oxygenase 2, reactive oxygen species and amyloid-beta 40/42 expression. These effects of curcumin on PI3K, Akt and Nrf2 were blocked by LY294002 (PI3k inhibitor) and NF-E2-related factor-2 siRNA. The results indicate that the cytoprotection conferred by curcumin on APPswe transfected SH-SY5Y cells is mediated by its ability to regulate the balance between heme oxygenase 1 and 2 via the PI3K/Akt/Nrf2 intracellular signaling pathway.展开更多
Throughout the globe,diabetes mellitus(DM) is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder.DM impacts multiple organs and af...Throughout the globe,diabetes mellitus(DM) is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder.DM impacts multiple organs and affects all components of the central and peripheral nervous systems that can range from dementia to diabetic neuropathy.The mechanistic target of rapamycin(m TOR) is a promising agent for the development of novel regenerative strategies for the treatment of DM.m TOR and its related signaling pathways impact multiple metabolic parameters that include cellular metabolic homeostasis,insulin resistance,insulin secretion,stem cell proliferation and differentiation,pancreatic β-cell function,and programmed cell death with apoptosis and autophagy.m TOR is central element for the protein complexes m TOR Complex 1(m TORC1) and m TOR Complex 2(m TORC2) and is a critical component for a number of signaling pathways that involve phosphoinositide 3-kinase(PI 3-K),protein kinase B(Akt),AMP activated protein kinase(AMPK),silent mating type information regulation 2 homolog 1(Saccharomyces cerevisiae)(SIRT1),Wnt1 inducible signaling pathway protein 1(WISP1),and growth factors.As a result,m TOR represents an exciting target to offer new clinical avenues for the treatment of DM and the complications of this disease.Future studies directed to elucidate the delicate balance m TOR holds over cellular metabolism and the impact of its broad signaling pathways should foster the translation of these targets into effective clinical regimens for DM.展开更多
We aim to investigate the effect of transforming growth factor (TGF)-β1 on the expression of enhancer of split- and hairy-related protein-2 (SHARP-2) messenger RNA (mRNA) and its signaling pathway. In this stud...We aim to investigate the effect of transforming growth factor (TGF)-β1 on the expression of enhancer of split- and hairy-related protein-2 (SHARP-2) messenger RNA (mRNA) and its signaling pathway. In this study, several cell lines including LLC-PK1 (a porcine kidney tubular epithelial cell line), MDCK (Madin-Darby canine kidney) and CTLL-2 (cytotoxic T-lymphocyte line) were treated with recombinant human TGF-131, and a series of experiments were carried out, involving Northern blot analysis of total RNA from these cells. Further, several specific chemical inhibitors were applied before TGF-β1 treatment to probe the signaling pathway. The results showed that TGF-β1 can significadtly up-regulate SHARP-2 mRNA expression in the LLC-PK1 cell line. The peak level of induction was found 2 h after TGF-β1 stimulation. While one phospho- inositide 3-kinases (PI-3) kinase inhibitor, LY294002, completely blocked the effect of TGF-131 on SHARP-2 mRNA expression in LLC-PK1 cells at a low concentration, other inhibitors, including PD98059, staurosporine, AG490, wortmannin, okadaic acid and rapamycin, had no effect. The effect of LY294002 was dose-dependent. We conclude that, in LLC-PK1 cells at least, TGF-β1 can effectively induce the SHARP-2 mRNA expression and that the PI-3 kinase pathway can mediate this effect.展开更多
基金National Natural Science Foundation of China,No.81704059Scientific Research Project of Hebei Province Traditional Chinese Medicine Administration,No.2017130。
文摘BACKGROUND Intestinal inflammation is a common digestive tract disease, which is usually treated with hormone medicines. Hormone medicines are effective to some extent, but long-term use of them may bring about many complications.AIM To explore the protective effects of panax notoginseng saponin(PNS) against dextran sulfate sodium(DSS)-induced intestinal inflammatory injury through phosphoinositide-3-kinase protein kinase B(PI3K/AKT) signaling pathway inhibition in rats.METHODS Colitis rat models were generated via DSS induction, and rats were divided into control(no modeling), DSS, DSS + PNS 50 mg/k, and DSS + PNS 100 mg/kg groups. Then, the intestinal injury, oxidative stress parameters, inflammatory indices, tight junction proteins, apoptosis, macrophage polarization, and TLR4/AKT signaling pathway in colon tissues from rats in each of the groups were detected. The PI3 K/AKT signaling pathway in the colon tissue of rats was blocked using the PI3K/AKT signaling pathway inhibitor, LY294002.RESULTS Compared with rats in the control group, rats in the DSS group showed significantly shortened colon lengths, and significantly increased disease activity indices, oxidative stress reactions and inflammatory indices, as well as significantly decreased expression of tight junction-associated proteins. In addition, the DSS group showed significantly increased apoptotic cell numbers,and showed significantly increased M1 macrophages in spleen and colon tissues.They also showed significantly decreased M2 macrophages in colon tissues, as well as activation of the PI3K/AKT signaling pathway(all P < 0.05). Compared with rats in the DSS group, rats in the DSS + PNS group showed significantly lengthened colon lengths, decreased disease activity indices, and significantly alleviated oxidative stress reactions and inflammatory responses. In addition, this group showed significantly increased expression of tight junction-associated proteins, significantly decreased apoptotic cell numbers, and significantly decreased M1 macrophages in spleen and colon tissues. This group further showed significantly increased M2 macrophages in colon tissues, and significantly suppressed activation of the PI3K/AKT signaling pathway, as well as a dose dependency(all P < 0.05). When the PI3K/AKT signaling pathway was inhibited, the apoptosis rate of colon tissue cells in the DSS + LY294002 group was significantly lower than that of the DSS group(P < 0.05).CONCLUSION PNS can protect rats against DSS-induced intestinal inflammatory injury by inhibiting the PI3K/AKT signaling pathway, and therefore may be potentially used in the future as a drug for colitis.
基金Supported by National Natural Science Foundation of China, No. U20A20408 and No. 82074450Natural Science Foundation of Hunan Province, No. 2020JJ4066+4 种基金Hunan Province"Domestic First-class Cultivation Discipline"Integrated Traditional Chinese and Western Medicine Open Fund Project, No. 2020ZXYJH34 and No. 2020ZXYJH35Hunan Graduate Scientific Research Innovation Project, No. QL20210173 and No. CX20210730Hunan Province Science and Technology Innovation Talents Plan College Students Science and Technology Innovation and Entrepreneurship Project, No. 2020RC1004Guangzhou Health Science and Technology Project, No. 20221A011102Hunan Traditional Chinese Medicine Scientific Research Project, No. 202101
文摘BACKGROUND The phosphoinositide 3-kinase/protein kinase-B/mechanistic target of rapamycin(PI3K/Akt/mTOR) signalling pathway is crucial for cell survival, differentiation, apoptosis and metabolism. Xihuang pills(XHP) are a traditional Chinese preparation with antitumour properties. They inhibit the growth of breast cancer, glioma, and other tumours by regulating the PI3K/Akt/mTOR signalling pathway. However, the effects and mechanisms of action of XHP in hepatocellular carcinoma(HCC) remain unclear. Regulation of the PI3K/Akt/mTOR signalling pathway effectively inhibits the progression of HCC. However, no study has focused on the XHPassociated PI3K/Akt/mTOR signalling pathway. Therefore, we hypothesized that XHP might play a role in inhibiting HCC through the PI3K/Akt/mTOR signalling pathway.AIM To confirm the effect of XHP on HCC and the possible mechanisms involved.METHODS The chemical constituents and active components of XHP were analysed using ultra-performance liquid chromatography-quadrupole time of flight mass spectrometry(UPLC-Q-TOF-MS). Cellbased experiments and in vivo xenograft tumour experiments were utilized to evaluate the effect of XHP on HCC tumorigenesis. First, SMMC-7721 cells were incubated with different concentrations of XHP(0, 0.3125, 0.625, 1.25, and 2.5 mg/mL) for 12 h, 24 h and 48 h. Cell viability was assessed using the CCK-8 assay, followed by an assessment of cell migration using a wound healing assay.Second, the effect of XHP on the apoptosis of SMMC-7721 cells was evaluated. SMMC-7721 cells were stained with fluorescein isothiocyanate and annexin V/propidium iodide. The number of apoptotic cells and cell cycle distribution were measured using flow cytometry. The cleaved protein and mRNA expression levels of caspase-3 and caspase-9 were detected using Western blotting and quantitative reverse-transcription polymerase chain reaction(RT-qPCR), respectively.Third, Western blotting and RT–qPCR were performed to confirm the effects of XHP on the protein and mRNA expression of components of the PI3K/Akt/mTOR signalling pathway.Finally, the effects of XHP on the tumorigenesis of subcutaneous hepatocellular tumours in nude mice were assessed.RESULTS The following 12 compounds were identified in XHP using high-resolution mass spectrometry:Valine, 4-gingerol, myrrhone, ricinoleic acid, glycocholic acid, curzerenone, 11-keto-β-boswellic acid, oleic acid, germacrone, 3-acetyl-9,11-dehydro-β-boswellic acid, 5β-androstane-3,17-dione, and 3-acetyl-11-keto-β-boswellic acid. The cell viability assay results showed that treatment with 0.625mg/mL XHP extract decreased HCC cell viability after 12 h, and the effects were dose-and timedependent. The results of the cell scratch assay showed that the migration of HCC cells was significantly inhibited in a time-dependent manner by the administration of XHP extract(0.625mg/mL). Moreover, XHP significantly inhibited cell migration and resulted in cell cycle arrest and apoptosis. Furthermore, XHP downregulated the PI3K/Akt/mTOR signalling pathway, which activated apoptosis executioner proteins(e.g., caspase-9 and caspase-3). The inhibitory effects of XHP on HCC cell growth were determined in vivo by analysing the tumour xenograft volumes and weights.CONCLUSION XHP inhibited HCC cell growth and migration by stimulating apoptosis via the downregulation of the PI3K/Akt/mTOR signalling pathway, followed by the activation of caspase-9 and caspase-3.Our findings clarified that the antitumour effects of XHP on HCC cells are mediated by the PI3K/Akt/mTOR signalling pathway, revealing that XHP may be a potential complementary therapy for HCC.
文摘Objective: The mechanisms by which lipopolysaccharide (LPS) pretreatment induces cardioprotection following ischaemia/reperfusion (I/R) have not been fully elucidated. We hypothesized that activation of phosphoinositide 3-kinase (PI3K)/Akt and high mobility group box 1 (HMGBxl) signaling plays an important role in LPS-induced cardioprotection. Methods: In in vivo experiments, age- and weight- matched male C57BL/10Sc wild type mice were pretreated with LPS before ligation of the left anterior descending coronary followed by reperfusion. Infarction size was examined by triphenyltetrazolium chloride (TTC) staining. Akt, phospho-Akt, and HMGBxl were assessed by immunoblotting with appropriate primary antibodies. In situ cardiac myocyte apop- tosis was examined by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. In an in vitro study, rat cardiac myoblasts (H9c2) were subdivided into two groups, and only one was pretreated with LPS. After pretreatment, the cells were transferred into a hypoxic chamber under 0.5% 02. Levels of HMGBxl were assessed by immunoblot. Results: In the in vivo experiment, pretreatment with LPS reduced the at risk infarct size by 70.6% and the left ventricle infarct size by 64.93% respectively. Pretreatment with LPS also reduced cardiac myocytes apoptosis by 39.1% after ischemia and reperfusion. The mechanisms of LPS induced cardioprotection involved increasing PI3K/Akt activity and decreasing expression of HMGBxl. In the in vitro study, pretreatment with LPS reduced the level of HMGBxl in H9c2 cell cytoplasm following hypoxia. Conclusion: The results suggest that the cardioprotection following I/R induced by LPS pretreatment involves PI3K/Akt and HMGBxl pathways.
文摘BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors.Osteopontin(OPN)is thought to be closely related to the occurrence,metastasis and prognosis of many types of tumors.AIM To investigate the effects of OPN on the proliferation,invasion and migration of GC cells and its possible mechanism.METHODS The mRNA and protein expression of OPN in the GC cells were analyzed by realtime quantitative-reverse transcription polymerase chain reaction and western blotting,and observe the effect of varying degree expression OPN on the proliferation and other behaviors of GC.Next,the effects of OPN knockdown on GC cells migration and invasion were examined.The short hairpin RNA(shRNA)and negative control shRNA targeting OPN-shRNA were transfected into the cells according to the manufacturer’s instructions.Non transfected cells were classified as control in the identical transfecting process.24 h after RNA transfection cell proliferation activity was detected by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide assay,and cell invasiveness and migration were detected by Trans well assay.Meanwhile,the expression of protein kinase B(AKT),matrix metalloproteinase 2(MMP-2)and vascular endothelial growth factor(VEGF)in the human GC cell lines was detected by reverse transcription polymerase chain reaction and western blotting.RESULTS The results of this study revealed that OPN mRNA and protein expression levels were highly expressed in SGC-7901 cells.OPN knockdown by specific shRNA noticeably reduced the capabilities of proliferation,invasion and migration of SGC-7901 cells.Moreover,in the experiments of investigating the underlying mechanism,results showed that OPN knockdown could down-regulated the expression of MMP-2 and VEGF,it also decreased the phosphorylation of AKT.Meanwhile,the protein expression levels of MMP-2,VEGF and phosphorylated AKT was noticeable lower than that in control group in the GC cells after they were added to phosphatidylinositol-3-kinase(PI3K)inhibitor(LY294002).CONCLUSION These results suggested that OPN though PI3K/AKT/mammalian target of rapamycin signal pathway to upregulate MMP-2 and VEGF expression,which contribute SGC-7901 cells to proliferation,invasion and migration.Thus,our results demonstrate that OPN may serve as a novel prognostic biomarkers as well as a potential therapeutic targets for GC.
基金Supported by Ministero dell’Universitàe della Ricerca Scientifica e Tecnologica(MURST,ex-60%to GM and EL)
文摘A large body of experimental and clinical data supports the notion that inflammation in acute pancreatitis has a crucial role in the pathogenesis of local and systemic damage and is a major determinant of clinical severity. Thus, research has recently focused on molecules that can regulate the inflammatory processes, such as phosphoinositide 3-kinases (PI3Ks), a family of lipid and protein kinases involved in intracellular signal transduction. Studies using genetic ablation or pharmacologic inhibitors of different PI3K isoforms, in particular the class I PI3Kδ and PI3Kγ, have contributed to a greater understanding of the roles of these kinases in the modulation of inflammatory and immune responses. Recent data suggest that PI3Ks are also involved in the pathogenesis of acute pancreatitis. Activation of the PI3K signaling pathway, and in particular of the class IB PI3Kγ isoform, has a significant role in those events which are necessary for the initiation of acute pancreatic injury, namely calcium signaling alteration, trypsinogen activation, and nuclear factor-κB transcription. Moreover, PI3Kγ is instrumental in modulating acinar cell apoptosis, and regulating local neutrophil infiltration and systemic inflammatory responses during the course of experimental acute pancreatitis. The availability of PI3K inhibitors selective for specific isoforms may provide new valuable therapeutic strategies to improve the clinical course of this disease. This article presents a brief summary of PI3K structure and function, and highlights recent advances that implicate PI3Ks in the pathogenesis of acute pancreatitis.
基金This project was supported by Ministry of Education Re-turning Overseas Scholar science study Foundation( 2 0 0 2 2 47) ,province Hubei Natural Sciences Foundation( 2 0 0 2 AB13 6) ,Wuhan science and Technology ChenguangPlan Foundation( 9910 0 2 0 9)
文摘To investigate the molecular mechanism of leptin regulating insulin secretion through determining the regulation of insulin secretion and the insulin receptor substrate (IRS)-2-associated phosphoinositide 3-kinase (PI3K) activity by leptin in the isolated rat pancreatic islets, pancreatic islets were isolated from male SD rats by the collagenase method. The purified islets were incubated with leptin 2 nmol/L for 1 h in the presence of 5.6 mmol/L or 11.1 mmol/L glucose. Insulin release was measured using radioimmunoassay. IRS-2-associated activity of PI3K was determined by immunoprecipitate assay and Western blot. The results showed that in the presence of 5.6 mmol/L glucose, leptin had no significant effect on both insulin secretion and IRS-2-associated PI3K activity, but in the presence of 11.1 mmol/L glucose, insulin release was significantly inhibited after the islets were exposed to leptin for 1 h (P<0.01). PI3K inhibitor wortmannin blocked the inhibitory regulation of leptin on insulin release (P<0.05). Western Blot assay revealed that 2 nmol/L leptin could significantly increase the IRS-2-associated activity of PI3K by 51.5 % (P<0.05) in the presence of 11.1 mmol/L glucose. It was concluded that Leptin could significantly inhibit insulin secretion in the presence of 11.1 mmol/L glucose by stimulating IRS-2-associated activity of PI3K, which might be the molecular mechanism of leptin regulating insulin secretion.
基金Supported by National Natural Science Foundation of China(81760806)Project of Traditional Chinese Medicine Administration of Gansu Province(GZK-2019-28)Innovation Ability Improvement Project of Higher Education Institutions of Gansu Province(2019B-103)。
文摘[Objectives]To explore the protective effects of Zuogui Pill on ^(60)Co-γ-ray-induced premature aging of rats based on phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR)signaling pathway.[Methods]Sixty sexually mature female SD rats were irradiated with ^(60)Co-γ-ray(6.0 Gy,LD 40)for 24 h at one time.These rats were randomly divided into model group,Progynova group[0.18(g·kg)/d],Progynova[0.09(g·kg)/d]+Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill medium dose[9.45(g·kg)/d)]group and Zuogui Pill low dose[4.725(g·kg)/d]group.The administration(once a day)lasted 21 d.The rat serum[follicle-stimulating hormone(FSH),luteinizing hormone(LH)and estradiol(E_(2))]were detected by Enzyme-linked immunosorbent assay(ELISA).The morphological changes of ovary were observed by hematoxylin-eosin(HE)staining.The apoptosis rate of granulosa cells was detected by terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling(TUNEL).The protein expression of phosphorylated(p)-PI3K,p-Akt,p-mTOR,B-cell lymphoma-2(Bcl-2),and Bcl-2-associated X protein(Bax)in ovarian tissues were detected by Western blot.[Results]Compared with the normal group,the model group showed significant increase in the serum FSH(P<0.01),significant decrease in serum E_(2)(P<0.05),and decrease in the number of early follicles and luteum in the ovary(P<0.01).Besides,the apoptosis rate of granulosa cells increased significantly(P<0.01);the expression of p-PI3K,p-Akt,p-mTOR and Bcl-2 in ovarian tissue decreased significantly,while the expression of Bax increased significantly(P<0.01).Compared with the model group,the number of early follicles in the ovary increased and the apoptosis rate of granulosa cells decreased after intervention in each administration group.In addition,the protein expressions of p-PI3K,p-Akt,p-mTOR and Bcl-2 increased,while the expression of Bax decreased,especially in Progynova+Zuogui Pill high dose group,the differences were statistically significant(P<0.05,P<0.01).[Conclusions]Zuogui Pill may protect the radiation-injured ovary through activating the expression of PI3K/Akt/mTOR protein in ovarian tissue,increasing the amount of Bcl-2 protein and inhibiting the expression of Bax protein.
基金Supported by The Natural Science Foundation of Heilongjiang Province, No. 2005-13
文摘AIM:To determine whether mitochondrial dysfunction resulting from high-fat diet is related to impairment of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt,also known as PKB) pathway. METHODS:Rat models of nonalcoholic fatty liver were established by high-fat diet feeding. The expression of total and phosphorylated P13K and Akt proteins in hepatocytes was determined by Western blotting. Degree of fat accumulation in liver was measured by hepatic triglyceride. Mitochondrial number and size were determined using quantitative morphometric analysis under transmission electron microscope. The permeability of the outer mitochondrial membrane was assessed by determining the potential gradient across this membrane.RESULTS:After Wistar rats were fed with high-fat diet for 16 wk,their hepatocytes displayed an accumulation of fat (103.1 ± 12.6 vs 421.5 ± 19.7,P < 0.01),deformed mitochondria (9.0% ± 4.3% vs 83.0% ± 10.9%,P < 0.05),and a reduction in the mitochondrial membrane potential (389.385% ± 18.612% vs 249.121% ± 13.526%,P < 0.05). In addition,the expression of the phosphorylated P13K and Akt proteins in hepatocytes was reduced,as was the expression of the anti-apoptotic protein Bcl-2,while expression of the pro-apoptotic protein caspase-3 was increased. When animals were treated with pharmacological inhibitors of P13K or Akt,instead of high-fat diet,a similar pattern of hepatocellular fat accumulation,mitochondrial impairment,and change in the levels of PI3K,Akt,Bcl-2 was observed. CONCLUSION:High-fat diet appears to inhibit the PI3K/Akt signaling pathway,which may lead to hepa-tocellular injury through activation of the mitochondrial membrane pathway of apoptosis.
基金National Natural Science Foundation of China(No.81490533)。
文摘Background: Autophagy of alveolar macrophages is a crucial process in ischemia/reperfusion injury-induced acute lung injury (ALI). Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent cells with the potential for repairing injured sites and regulating autophagy. This study was to investigate the influence of BM-MSCs on autophagy of macrophages in the oxygen-glucose deprivation/restoration (OGD/R) microenvironment and to explore the potential mechanism.Methods: We established a co-culture system of macrophages (RAW264.7) with BM-MSCs under OGD/R conditionsin vitro. RAW264.7 cells were transfected with recombinant adenovirus (Ad-mCherry-GFP-LC3B) and autophagic status of RAW264.7 cells was observed under a fluorescence microscope. Autophagy-related proteins light chain 3 (LC3)-I, LC3-II, and p62 in RAW264.7 cells were detected by Western blotting. We used microarray expression analysis to identify the differently expressed genes between OGD/R treated macrophages and macrophages co-culture with BM-MSCs. We investigated the gene heme oxygenase-1 (HO-1), which is downstream of the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway.Results: The ratio of LC3-II/LC3-I of OGD/R treated RAW264.7 cells was increased (1.27 ± 0.20vs. 0.44 ± 0.08,t = 6.67,P < 0.05), while the expression of p62 was decreased (0.77 ± 0.04vs. 0.95 ± 0.10,t = 2.90,P < 0.05), and PI3K (0.40 ± 0.06vs. 0.63 ± 0.10,t = 3.42,P < 0.05) and p-Akt/Akt ratio was also decreased (0.39 ± 0.02vs. 0.58 ± 0.03,t = 9.13,P < 0.05). BM-MSCs reduced the LC3-II/LC3-I ratio of OGD/R treated RAW264.7 cells (0.68 ± 0.14vs. 1.27 ± 0.20,t = 4.12,P < 0.05), up-regulated p62 expression (1.10 ± 0.20vs. 0.77 ± 0.04,t = 2.80,P < 0.05), and up-regulated PI3K (0.54 ± 0.05vs. 0.40 ± 0.06,t = 3.11,P < 0.05) and p-Akt/Akt ratios (0.52 ± 0.05vs. 0.39 ± 0.02,t = 9.13,P < 0.05). A whole-genome microarray assay screened the differentially expressed geneHO-1, which is downstream of the PI3K/Akt signaling pathway, and the alteration ofHO-1 mRNA and protein expression was consistent with the data on PI3K/Akt pathway.Conclusions: Our results suggest the existence of the PI3K/Akt/HO-1 signaling pathway in RAW264.7 cells under OGD/R circumstancesin vitro, revealing the mechanism underlying BM-MSC-mediated regulation of autophagy and enriching the understanding of potential therapeutic targets for the treatment of ALI.
基金supported by the National Natural Science Foundation of China No.81072901the New Teacher Fund for Doctor Station,Ministry of Education,No.20120013110013+1 种基金grants from the Nautical Traditional Chinese Medicine Discipline,No.522/0100604054grants from the Nautical Traditional Chinese Medicine Collaborative Innovation Center,No.522/0100604299
文摘Tongluojiunao (TLJN) is an herbal medicine consisting of two main components, geniposide and ginsenoside Rg1. TLJN has been shown to protect primary cultured hippocampal neurons. How-ever, its mechanism of action remains unclear. In the present study, primary cultured hippocampal neurons treated with Aβ1-42 (10 μmol/L) signiifcantly increased the release of lactate dehydroge-nase, which was markedly reduced by TLJN (2 μL/mL), speciifcally by the component geniposide (26 μmol/L), but not ginsenoside Rg1 (2.5 μmol/L). hTe estrogen receptor inhibitor, ICI182780 (1 μmol/L), did not block TLJN-or geniposide-mediated decrease of lactate dehydrogenase under Aβ1-42-exposed conditions. However, the phosphatidyl inositol 3-kinase or mitogen-activated protein kinase pathway inhibitor, LY294002 (50 μmol/L) or U0126 (10 μmol/L), respectively blo cked the decrease of lactate dehydrogenase mediated by TLJN or geniposide. hTerefore, these results suggest that the non-classical estrogen pathway (i.e., phosphatidyl inositol 3-kinase or mitogen-activated protein kinase) is involved in the neuroprotective effect of TLJN, speciifcally its component, geniposide, against Aβ1-42-mediated cell death in primary cultured hippocampal neurons.
基金Supported by the National Natural Science Foundation of China(31872377)。
文摘The study was conducted to investigate the effect and mechanism of dietary quercetin supplementation on protein utilization of Arbor Acres(AA)broilers.A total of 2401-day-old AA broilers were randomly allocated to four treatments with six replicates,comprising 10 broilers each replicate(60 broilers per treatment).Birds were fed either a corn-soybean meal basal diet without quercetin(control)or a basal diet supplemented with 0.2,0.4 or 0.6 g of quercetin per kg feed,and the trial lasted 42 days.Dietary quercetin supplementation tended to increase the apparent metabolic rate of protein(p=0.076)and the content of serum albumin(p=0.062)in AA broilers.Compared with the control,dietary quercetin supplementation increased the contents of protein in breast muscle(p<0.05)and in thigh muscle(p=0.053).In addition,quercetin up-regulated mRNA expression of insulin-like growth factor 1(IGF-1),phosphatidylinositol 3-kinase(PI3K),target of rapamycin(TOR),ribosomal protein S6 kinase 1(S6K1),eukaryotic translation initiation factor 4E(eIF4E),eukaryotic translation initiation factor 4G(eIF4G),eukaryotic elongation factor 2(eEF2)and eukaryotic translation initiation factor 4B(eIF4B)genes and down-regulated mRNA expression of eukaryotic elongation factor 2 kinase(eEF2K)and eukaryotic initiation factor 4E binding protein1(4E-BP1)genes in breast muscle,thigh muscle and liver of AA broilers(p<0.05).The present results suggested that dietary quercetin supplementation enhanced protein utilization in broilers by activating TOR signaling pathway.
文摘Background: Nucleoside reverse transcriptase inhibitors (NRTIs) are the earliest and most commonly used anti-human immunodeficiency virus drugs and play an important role in high active antiretroviral therapy. However, NRTI drug therapy can cause peripheral neuropathic pain. In this study, we aimed to investigate the mechanisms ofrapamycin on the pain sensitization of model mice by in vivo experiments to explore the effect of mammalian target of rapamycin (mTOR) in the pathogenesis ofneuropathic pain caused by NRTIs. Methods: Male Kun Ming (KM) mice weighing 20-2 g were divided into control, 2 mg/kg rapamycin, 12 mg/kg stavudine, and CMC-Na groups. Drugs were orally administered to mice for 42 consecutive days. The von Frey filament detection and thermal pain tests were conducted on day 7, 14, 21, 28, 35, and 42 after drug administration. After the last behavioral tests, immunohistochemistry and western blotting assay were used for the measurement of mTOR and other biomarkers. Multivariate analysis of variance was used. Results: The beneficial effects ofrapamycin on neuropathic pain were attributed to a reduction in mammalian target of rapamycin sensitive complex 1 (mTORC1)-positive cells (70.80± 2.41 vs. 112.30 ± 5.66, F = 34.36, P 〈 0.01 ) and mTORC1 activity in the mouse spinal cord. Mechanistic studies revealed that Protein Kinase B (Akt)/mTOR signaling pathway blockade with rapamycin prevented the phosphorylation of mTORC1 in stavudine-intoxicated mice (0.72 ± 0.04 vs. 0.86 ± 0.03, F=4.24, P = 0.045), as well as decreased the expression of phospho-pTOS6K (0.47 ± 0.01 vs. 0.68 ± 0.03, F=6.01, P = 0.022) and phospho-4EBP1 (0.90 ± 0.04 vs. 0.94 ± 0.06, F= 0.28, P = 0.646). Conclusions: Taken together, these results suggest that stavudine elevates the expression and activity of mTORC1 in the spinal cord through activating the Akt/mTOR signaling pathway. The data also provide evidence that rapamycin might be useful for the treatment of peripheral neuropathic pain.
基金Supported by the Special Scientific Research Project of the Chinese Medicine Industry of the State Administration of Traditional Chinese Medicine of China(No.201307006)National Natural Science Foundation of China(No.82104656,82004179,82074405)Fundamental Research Funds for the Central Public Welfare Research Institutes(No.ZZ14-YQ-013,ZZ15-YQ-024)。
文摘Objective:To investigate whether Buthus martensii karsch(Scorpiones),Scolopendra subspinipes mutilans L.Koch(Scolopendra)and Gekko gecko Linnaeus(Gekko)could ameliorate the hypoxic tumor microenvironment and inhibit lung cancer growth and metastasis by regulating phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin/hypoxia-inducible factor-1α(PI3K/AKT/mTOR/HIF-1α)signaling pathway.Methods:Male C57BL/6J mice were inoculated with luciferase labeled LL/2-luc-M38 cell suspension to develop lung cancer models,with rapamycin and cyclophosphamide as positive controls.Carboxy methyl cellulose solutions of Scorpiones,Scolopendra and Gekko were administered intragastrically as 0.33,0.33,and 0.83 g/kg,respectively once daily for 21 days.Fluorescent expression were detected every 7 days after inoculation,and tumor growth curves were plotted.Immunohistochemistry was performed to determine CD31 and HIF-1αexpressions in tumor tissue and microvessel density(MVD)was analyzed.Western blot was performed to detect the expression of PI3K/AKT/mTOR/HIF-1αsignaling pathway-related proteins.Enzyme-linked immunosorbent assay was performed to detect serum basic fibroblast growth factor(bFGF),transforming growth factor-β1(TGF-β1)and vascular endothelial growth factor(VEGF)in mice.Results:Scorpiones,Scolopendra and Gekko prolonged the survival time and inhibited lung cancer metastasis and expression of HIF-1α(all P<0.01).Moreover,Scorpiones,Scolopendra and Gekko inhibited the phosphorylation of AKT and ribosomal protein S6 kinase(p70S6K)(P<0.05 or P<0.01).In addition,they also decreased the expression of CD31,MVD,bFGF,TGF-β1 and VEGF compared with the model group(P<0.05 or P<0.01).Conclusion:Scorpiones,Scolopendra and Gekko all showed beneficial effects on lung cancer by ameliorating the hypoxic tumor microenvironment via PI3K/AKT/mTOR/HIF-1αsignaling pathway.
基金Youth Program of the National Natural Science Foundation of China (to YX)(No. 82003309)
文摘The phosphosphatidylinositol-3-kinase(PI3K)signaling pathway is one of the most important intracellular signal transduction pathways affecting cell functions,such as apoptosis,translation,metabolism,and angiogenesis.Lung cancer is a malignant tumor with the highest morbidity and mortality rates in the world.It can be divided into two groups,non-small cell lung cancer(NSCLC)and small cell lung cancer(SCLC).NSCLC accounts for>85%of all lung cancers.There are currently many clinical treatment options for NSCLC;however,traditional methods such as surgery,chemotherapy,and radiotherapy have not been able to provide patients with good survival benefits.The emergence of molecular target therapy has improved the survival and prognosis of patients with NSCLC.In recent years,there have been an increasing number of studies on NSCLC and PI3K signaling pathways.Inhibitors of various parts of the PI3K pathway have appeared in various phases of clinical trials with NSCLC as an indication.This article focuses on the role of the PI3K signaling pathway in the occurrence and development of NSCLC and summarizes the current clinical research progress and possible development strategies.
基金Supported by Natural Science Foundation of Zhejiang Province(No.LQ23H270001)。
文摘Objective:To investigate the hemostatic effect of modified Sijunzi Granules(MSG)in primary immune thrombocytopenia(ITP)zebrafish model and explore the potential mechanism.Methods:AB strain wild type zebrafish were treated with simvastatin(6μmol/L)for 24 h to establish the hemorrhage model(model control group).The zebrafish were treated with MSG at different doses(55.6,167,and 500μg/mL),respectively.The hemostatic effect was assessed by examining the intestinal bleeding and hemostatic rate.5-hydroxytryptamine(5-HT)content was determined using enzyme-linked immunosorbent assay(ELISA)assay.The expressions of5-HT2aR,5-HT2bR,and SERT genes were detected by quantitative real-time polymerase chain reaction(PCR).The protein expressions of protein kinase B(Akt),p-Akt,extracellular regulated protein kinases(Erk),and p-Erk were examined using Western blot analysis.Results:The intestinal bleeding rate was 37%,40%,and 80%in the55.6,167,and 500μg/mL dose of MSG,respectively,in which 55.6 and 167μg/mL MSG dose groups were associated with significantly decreased intestinal bleeding rate when compared with the model control group(70%,P<0.05).Significantly higher hemostatic rates were also observed in the 55.6μg/mL(54%)and 167μg/mL(52%)MSG dose groups(P<0.05).MSG increased the 5-HT content and mRNA expression levels of 5-HT2aR,5-HT2bR,and SERT(P<0.05).In addition,caspase3/7 activity was inhibited(P<0.05).Significant increase in p-Akt and p-Erk was also detected after treatment with MSG(P<0.05).Conclusions:MSG could reduce the incidence and severity of intestinal bleeding in zebrafish by activating MAPK/Erk and PI3K/Akt signal pathways through regulating the levels of 5-HT and its receptors,which may provide evidence for the treatment of ITP.
基金Supported by the Key Program of Shandong Province,China,No.2016CYJS08A01-6.
文摘BACKGROUND In China banxia xiexin decoction(BXD)has been used in treating gastric cancer(GC)for thousands of years and BXD has a good role in reversing GC histopathology,but its chemical composition and action mechanism are still unknown.AIM To investigate the mechanism of action of BXD against GC based on transcriptomics,network pharmacology,in vivo and in vitro experiments.METHODS The transplanted tumor model was prepared,and the nude mouse were pathologically examined after administration,and hematoxylin-eosin staining was performed.The active ingredients of BXD were quality controlled and identified using ultra-performance liquid chromatography tandem quadrupole electrostatic field orbitrap mass spectrometry(UPLC-Q-Orbitrap MS/MS),and traditional Chinese medicines systems pharmacology platform,drug bank and the Swiss target prediction platform to predict the relevant targets,the differentially expressed genes(DEGs)of GC were screened by RNA-seq sequencing,and the overlapping targets were analyzed to obtain the key targets and pathways.Cell Counting Kit-8,apoptosis assay,cell migration and Realtime fluorescence quantitative polymerase chain reaction were used for in vitro experiments.RESULTS All dosing groups inhibited the growth of transplanted tumors in laboratory-bred strain nude,with the capecitabine group and the BXD medium-dose group being the best.A total of 29 compounds and 859 potential targets in BXD were identified by UPLC-Q-Orbitrap MS/MS and network pharmacology,RNA-seq sequencing found 4767 GC DEGs,which were combined with network pharmacology and analyzed 246 potential therapeutic targets were obtained and pathway results showed that BXD may against GC through the Phosphoinositide 3-kinase(PI3K)/protein kinase B(AKt)signaling pathway.In vitro cellular experiments confirmed that BXDcontaining serum and LY294002 could inhibit the proliferation of GC cells,promote apoptosis,and inhibit the migration of GC cells by decreasing the expression of EGFR,PIK3CA,IL6,BCL2 and AKT1 in the PI3K-Akt pathway in MGC-803 expression.CONCLUSION BXD has the effect of inhibiting tumor growth rate and delaying the development of GC.Its mechanism of action may be related to the regulation of PI3K-Akt signaling pathway.
文摘Pancreatic cancer is a highly aggressive tumour that is very resistant to treatments and it is rarely diagnosed early because of absence of specific symptoms. Therefore, the prognosis for this disease is very poor and it has the grim supremacy in terms of unfavourable survival rates. There have been great advances in survival rates for many types of cancers over the past few decades but hardly any change for pancreatic cancer. Mutations of the Ras oncogene are the most frequent oncogenic alterations in human cancers. The frequency of KRAS mutations in pancreatic cancer is around 90%. Given the well-established role of KRAS in cancer it is not surprising that it is one of the most attractive targets for cancer therapy. Nevertheless, during the last thirty years all attempts to target directly KRAS protein have failed. Therefore, it is crucial to identify downstream KRAS effectors in order to develop specific drugs able to counteract activation of this pathway. Among the different signalling pathways activated by oncogenic KRAS, the phosphoinositide 3-Kinase(PI3K) pathway is emerging as one of the most critical KRAS effector. In turn, PI3 K activates several parallel pathways making the identification of the precise effectors activated by KRAS/PI3 K more difficult. Recent data identify 3-phosphoinositide-dependent protein kinase 1 as a key tumour-initiating event downstream KRAS interaction with PI3 K in pancreatic cancer.
基金supported by the National Science Foundation of China,No.30973154the Science Foundation of Chongqing,No.2009BB5270the Chongqing Municipal Education Commission Foundation,No.KJ090301
文摘The APPswe plasmid was transfected into the neuroblastoma cell line SH-SY5Y to establish a cell model of Alzheimer's disease. Graded concentration and time course experiments demonstrate that curcumin significantly upregulates phosphatidylinositol 3-kinase (PI3K), Akt, nuclear factor E2-related factor-2 (Nrf2), heme oxygenase 1 and ferritin expression, and that it significantly downregulates heme oxygenase 2, reactive oxygen species and amyloid-beta 40/42 expression. These effects of curcumin on PI3K, Akt and Nrf2 were blocked by LY294002 (PI3k inhibitor) and NF-E2-related factor-2 siRNA. The results indicate that the cytoprotection conferred by curcumin on APPswe transfected SH-SY5Y cells is mediated by its ability to regulate the balance between heme oxygenase 1 and 2 via the PI3K/Akt/Nrf2 intracellular signaling pathway.
基金supported by American Diabetes Association,American Heart Association,NIH NIEHS,NIH NIA,NIH NINDS,and NIH ARRA
文摘Throughout the globe,diabetes mellitus(DM) is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder.DM impacts multiple organs and affects all components of the central and peripheral nervous systems that can range from dementia to diabetic neuropathy.The mechanistic target of rapamycin(m TOR) is a promising agent for the development of novel regenerative strategies for the treatment of DM.m TOR and its related signaling pathways impact multiple metabolic parameters that include cellular metabolic homeostasis,insulin resistance,insulin secretion,stem cell proliferation and differentiation,pancreatic β-cell function,and programmed cell death with apoptosis and autophagy.m TOR is central element for the protein complexes m TOR Complex 1(m TORC1) and m TOR Complex 2(m TORC2) and is a critical component for a number of signaling pathways that involve phosphoinositide 3-kinase(PI 3-K),protein kinase B(Akt),AMP activated protein kinase(AMPK),silent mating type information regulation 2 homolog 1(Saccharomyces cerevisiae)(SIRT1),Wnt1 inducible signaling pathway protein 1(WISP1),and growth factors.As a result,m TOR represents an exciting target to offer new clinical avenues for the treatment of DM and the complications of this disease.Future studies directed to elucidate the delicate balance m TOR holds over cellular metabolism and the impact of its broad signaling pathways should foster the translation of these targets into effective clinical regimens for DM.
基金supported by the National Natural Science Foundation of China (Nos. 30471641 and 30872389)the Natural Science Foundation of Zhejiang Province, China (No. Y207088)
文摘We aim to investigate the effect of transforming growth factor (TGF)-β1 on the expression of enhancer of split- and hairy-related protein-2 (SHARP-2) messenger RNA (mRNA) and its signaling pathway. In this study, several cell lines including LLC-PK1 (a porcine kidney tubular epithelial cell line), MDCK (Madin-Darby canine kidney) and CTLL-2 (cytotoxic T-lymphocyte line) were treated with recombinant human TGF-131, and a series of experiments were carried out, involving Northern blot analysis of total RNA from these cells. Further, several specific chemical inhibitors were applied before TGF-β1 treatment to probe the signaling pathway. The results showed that TGF-β1 can significadtly up-regulate SHARP-2 mRNA expression in the LLC-PK1 cell line. The peak level of induction was found 2 h after TGF-β1 stimulation. While one phospho- inositide 3-kinases (PI-3) kinase inhibitor, LY294002, completely blocked the effect of TGF-131 on SHARP-2 mRNA expression in LLC-PK1 cells at a low concentration, other inhibitors, including PD98059, staurosporine, AG490, wortmannin, okadaic acid and rapamycin, had no effect. The effect of LY294002 was dose-dependent. We conclude that, in LLC-PK1 cells at least, TGF-β1 can effectively induce the SHARP-2 mRNA expression and that the PI-3 kinase pathway can mediate this effect.