Dapagliflozin exerts anti-apoptotic effects by mitigating macrophage polarization via modulation of the phosphoinositide 3-kinase/protein kinase B signaling pathway

BACKGROUND Macrophages are central to the orchestration of immune responses,inflammatory processes,and the pathogenesis of diabetic complications.The dynamic polarization of macrophages into M1 and M2 phenotypes critically modulates inflammation and contributes to the progression of diabetic nephropathy.Sodiumglucose cotransporter 2 inhibitors such as dapagliflozin,which are acclaimed for their efficacy in diabetes management,may influence macrophage polarization,thereby ameliorating diabetic nephropathy.This investigation delves into these mechanistic pathways,aiming to elucidate novel therapeutic strategies for diabetes.AIM To investigate the inhibitory effect of dapagliflozin on macrophage M1 polarization and apoptosis and to explore its mechanism of action.METHODS We established a murine model of type 2 diabetes mellitus and harvested peritoneal macrophages following treatment with dapagliflozin.Concurrently,the human monocyte cell line cells were used for in vitro studies.Macrophage viability was assessed in a cell counting kit 8 assay,whereas apoptosis was evaluated by Annexin V/propidium iodide staining.Protein expression was examined through western blotting,and the expression levels of macrophage M1 surface immunosorbent assay,and quantitative real-time polymerase chain reaction analyses.RESULTS Dapagliflozin attenuated M1 macrophage polarization and mitigated apoptosis in the abdominal macrophages of diabetic mice,evidenced by the downregulation of proapoptotic genes(Caspase 3),inflammatory cytokines[interleukin(IL)-6,tumor necrosis factor-α,and IL-1β],and M1 surface markers(inducible nitric oxide synthase,and cluster of differentiation 86),as well as the upregulation of the antiapoptotic gene BCL2.Moreover,dapagliflozin suppressed the expression of proteins associated with the phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)signaling pathway(PI3K,AKT,phosphorylated protein kinase B).These observations were corroborated in vitro,where we found that the modulatory effects of dapagliflozin were abrogated by 740Y-P,an activator of the PI3K/AKT signaling pathway.CONCLUSION Dapagliflozin attenuates the polarization of macrophages toward the M1 phenotype,thereby mitigating inflammation and promoting macrophage apoptosis.These effects are likely mediated through the inhibition of the PI3K/AKT signaling pathway.

Protective effects of panax notoginseng saponin on dextran sulfate sodium-induced colitis in rats through phosphoinositide-3-kinase protein kinase B signaling pathway inhibition

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.

Osteopontin promotes gastric cancer progression via phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway

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.

Telencephalin protects PAJU cells from amyloid beta protein-induced apoptosis by activating the ezrin/radixin/moesin protein family/phosphatidylinositol-3-kinase/protein kinase B pathway

Telencephalin is a neural glycoprotein that reduces apoptosis induced by amyloid beta protein in the human neural tumor cell line PAJU. In this study, we examined the role of the ezrin/radixin/moesin protein family/phosphatidylinositol-3-kinase/protein kinase B pathway in this process. Western blot analysis demonstrated that telencephalin, phosphorylated ezrin/radixin/moesin and phosphatidylinositol-3-kinase/protein kinase B were not expressed in PAJU cells transfected with empty plasmid, while they were expressed in PAJU cells transfected with a telencephalin expression plasmid. After treatment with 1.0 nM amyloid beta protein 42, expression of telencephalin and phosphorylated phosphatidylinositol-3-kinase/protein kinase B in the transfected cells gradually diminished, while levels of phosphorylated ezrin/radixin/moesin increased. In addition, the high levels of telencephalin, phosphorylated ezrin/radixin/moesin and phosphatidylinositol-3-kinase/protein kinase B expression in PAJU cells transfected with a telencephalin expression plasmid could be suppressed by the phosphatidylinositol-3-kinase inhibitor LY294002. These findings indicate that telencephalin activates the ezrin/radixin/moesin family/phosphatidylinositol-3-kinase/protein kinase B pathway and protects PAJU cells from amyloid beta protein-induced apoptosis.

Xuebijing improves intestinal microcirculation dysfunction in septic rats by regulating the VEGF-A/PI3K/Akt signaling pathway

BACKGROUND:This study aims to explore whether Xuebijing(XBJ) can improve intestinal microcirculation dysfunction in sepsis and its mechanism.METHODS:A rat model of sepsis was established by cecal ligation and puncture(CLP).A total of 30 male SD rats were divided into four groups:sham group,CLP group,XBJ + axitinib group,and XBJ group.XBJ was intraperitoneally injected 2 h before CLP.Hemodynamic data(blood pressure and heart rate) were recorded.The intestinal microcirculation data of the rats were analyzed via microcirculation imaging.Enzyme-linked immunosorbent assay(ELISA) kits were used to detect the serum levels of interleukin-6(IL-6),C-reactive protein(CRP),and tumor necrosis factor-α(TNF-α) in the rats.Histological analysis and transmission electron microscopy were used to analyze the injury of small intestinal microvascular endothelial cells and small intestinal mucosa in rats.The expression of vascular endothelial growth factor A(VEGF-A),phosphoinositide 3-kinase(PI3K),phosphorylated PI3K(p-PI3K),protein kinase B(Akt),and phosphorylated Akt(p-Akt) in the small intestine was analyzed via Western blotting.RESULTS:XBJ improved intestinal microcirculation dysfunction in septic rats,alleviated the injury of small intestinal microvascular endothelial cells and small intestinal mucosa,and reduced the systemic inflammatory response.Moreover,XBJ upregulated the expression of VEGF-A,p-PI3K/total PI3K,and p-Akt/total Akt in the rat small intestine.CONCLUSION:XBJ may improve intestinal microcirculation dysfunction in septic rats possibly through the VEGF-A/PI3K/Akt signaling pathway.

Human neural stem cell-derived extracellular vesicles protect against ischemic stroke by activating the PI3K/AKT/mTOR pathway

Human neural stem cell-derived extracellular vesicles exhibit analogous functions to their parental cells,and can thus be used as substitutes for stem cells in stem cell therapy,thereby mitigating the risks of stem cell therapy and advancing the frontiers of stem cell-derived treatments.This lays a foundation for the development of potentially potent new treatment modalities for ischemic stroke.However,the precise mechanisms underlying the efficacy and safety of human neural stem cell-derived extracellular vesicles remain unclear,presenting challenges for clinical translation.To promote the translation of therapy based on human neural stem cell-derived extracellular vesicles from the bench to the bedside,we conducted a comprehensive preclinical study to evaluate the efficacy and safety of human neural stem cell-derived extracellular vesicles in the treatment of ischemic stroke.We found that administration of human neural stem cell-derived extracellular vesicles to an ischemic stroke rat model reduced the volume of cerebral infarction and promoted functional recovery by alleviating neuronal apoptosis.The human neural stem cell-derived extracellular vesicles reduced neuronal apoptosis by enhancing phosphorylation of phosphoinositide 3-kinase,mammalian target of rapamycin,and protein kinase B,and these effects were reversed by treatment with a phosphoinositide 3-kinase inhibitor.These findings suggest that human neural stem cell-derived extracellular vesicles play a neuroprotective role in ischemic stroke through activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway.Finally,we showed that human neural stem cell-derived extracellular vesicles have a good in vivo safety profile.Therefore,human neural stem cell-derived extracellular vesicles are a promising potential agent for the treatment of ischemic stroke.

Bone marrow mesenchymal stem cells promote uterine healing by activating the PI3K/AKT pathway and modulating inflammation in rat models

BACKGROUND Uterine injury can cause uterine scarring,leading to a series of complications that threaten women’s health.Uterine healing is a complex process,and there are currently no effective treatments.Although our previous studies have shown that bone marrow mesenchymal stem cells(BMSCs)promote uterine damage repair,the underlying mechanisms remain unclear.However,exploring the specific regulatory roles of BMSCs in uterine injury treatment is crucial for further understanding their functions and enhancing therapeutic efficacy.AIM To investigate the underlying mechanism by which BMSCs promote the process of uterine healing.METHODS In in vivo experiments,we established a model of full-thickness uterine injury and injected BMSCs into the uterine wound.Transcriptome sequencing was per-formed to determine the enrichment of differentially expressed genes at the wound site.In in vitro experiments,we isolated rat uterine smooth muscle cells(USMCs)and cocultured them with BMSCs to observe the interaction between BMSCs and USMCs in the microenvironment.RESULTS We found that the differentially expressed genes were mainly related to cell growth,tissue repair,and angiogenesis,while the phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)pathway was highly enriched.Quantitative reverse-transcription polymerase chain reaction was used to validate differentially expressed genes,and the results demonstrated that BMSCs can upregulate genes related to regeneration and downregulate genes related to inflammation.Coculturing BMSCs promoted the migration and proliferation of USMCs,and the USMC microenvironment promoted the myogenic differentiation of BMSCs.Finally,we validated the PI3K/AKT pathway in tissues and cells and showed that BMSCs activate the PI3K/AKT pathway to promote the regeneration of uterine smooth muscle both in vivo and in vitro.CONCLUSION BMSCs upregulated uterine wound regeneration and anti-inflammatory factors and enhanced uterine smooth muscle proliferation through the PI3K/AKT pathway both in vivo and in vitro.

Multiple implications of 3-phosphoinositide-dependent protein kinase 1 in human cancer

3-phosphoinositide-dependent protein kinase-1(PDK1) is a central mediator of cellular signaling between phosphoinositide-3 kinase and various intracellular serine/threonine kinases,including protein kinase B,p70 ribosomal S6 kinase,serum and glucocorticoid-inducible kinase,and protein kinase C.PDK1 activates members of the AGC family of protein kinases by phosphorylating serine/threonine residues in the activation loop.Here,we review the regulatory mechanisms of PDK1 and its roles in cancer.PDK1 is activated by autophosphorylation in the activation loop and other serine residues,as well as by phosphorylation of Tyr-9 and Tyr-373/376.Src appears to recognize PDK1 following tyrosine phosphorylation.The role of heat shock protein 90 in regulating PDK1 stability and PDK1-Src complex formation are also discussed.Furthermore,we summarize the subcellular distribution of PDK1.Finally,an important role for PDK1 in cancer chemotherapy is proposed.In conclusion,a better understanding of its molecular regulatory mechanisms in various signaling pathways will help to explain how PDK1 acts as an oncogenic kinase in various cancers,and will contribute to the development of novel cancer chemotherapies.

Bone marrow-derived mesenchymal stem cells modulate autophagy in RAW264.7 macrophages via the phosphoinositide 3-kinase/protein kinase B/heme oxygenase-1 signaling pathway under oxygen-glucose deprivation/restoration conditions

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.

Regulatory Effects of Zuogui Pill on Apoptosis of Follicles in Rats Injured by 60Co-γRays Based on PI3K/Akt/m TOR Signaling Pathway

[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.

Geniposide, the component of the Chinese herbal formula Tongluojiunao, protects amyloid-β peptide(1–42)-mediated death of hippocampal neurons via the non-classical estrogen signaling pathway

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.

Influence of Phosphatidylinositol-3-Kinase/Protein Kinase B-Mammalian Target of Rapamycin Signaling Pathway on the Neuropathic Pain Complicated by Nucleoside Reverse Transcriptase Inhibitors for the Treatment of HIV Infection

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.

TopoisomeraseⅡalpha promotes gallbladder cancer proliferation and metastasis through activating phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway

Background:TopoisomeraseⅡalpha(TOP2A)has been reported to play a crucial role in the tumorigenesis of various cancer types.However,the biological role of TOP2A in gallbladder cancer(GBC)remains unknown.The current study aimed to explore the function and potential mechanism of TOP2A in GBC.Methods:Based on Gene Expression Profiling Interactive Analysis data,we found TOP2A was significantly up-regulated in GBC tissues and resulting in shorter overall survival.Quantitative real-time polymerase chain reaction and immunohistochemistry were conducted to detect the expression of TOP2A in 45 pairs of GBC tissues and adjacent non-tumor tissues.In vitro,cell proliferation,migration,and invasion ability were examined by cell counting kit-8 and transwell assay,respectively.Epithelial-mesenchymal transition(EMT)related and phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR)pathway-related markers were measured by Western blotting.Xenograft model assay was performed to evaluate the effect of TOP2A in vivo.Results:TOP2A was found up-regulated in GBC(tumor vs.normal,12.62 vs.0.34)and correlated with the late tumor node metastasis stage(P=0.0032),present of lymph node metastasis(P=0.0273),and poor prognosis in GBC patients(log-rank P=0.028).In vitro and in vivo assays showed that knockdown of TOP2A notably inhibited cell proliferation,migration,invasion,EMT process,and tumor growth in GBC.In addition,TOP2A down-regulation significantly decreased the protein levels of phosphor(p)-PI3K,p-Akt,and p-mTOR.Conclusion:Our study demonstrates that TOP2A was overexpressed in GBC and associated with poor prognosis in GBC patients.TOP2A promotes GBC cell proliferation,migration,invasion,EMT process,and tumor growth through activating PI3K/Akt/mTOR signaling pathway,and may serve as a novel prognostic biomarker and therapeutic target for GBC.

Bornyl acetate extracted from Sharen(Fructus Amomi)inhibits proliferation,invasion and induces apoptosis by suppressing phosphatidylinositol-3-kinase/protein kinase B signaling in colorectal cancer

OBJECTIVE:To investigate the antitumor effects of bornyl acetate(BA)isolated from Sharen(Fructus Amomi)in colorectal cancer(CRC)and the underlying mechanisms.METHODS:SW480 and HT29 cells were treated with increasing doses of BA in order to determine its antitumor effects in vitro.Cell viability,colony formation,cell cycle,and apoptosis as well as migration and invasion were assessed using various assays.In addition,the in vivo antitumor effects of BA were assessed using a xenograft mouse model.We then assessed the mechanism of action of BA by conducting pathway activator-mediated rescue experiments and assessed the protein levels by Western blot analysis.RESULTS:BA showed anti-CRC tumor activities in vitro by suppressing cell proliferation and colony formation,inducing apoptosis,blocking cell cycle,and inhibiting migration and invasion.These effects were mediated via suppression of the phosphatidylinositol-3-kinase/protein kinase B(PI3K/AKT)pathway.In the tumor xenograft experiment,BA was found to repress tumor growth in vivo with low toxicity.CONCLUSIONS:The results demonstrated that BA exerts antitumor effects by suppressing the PI3K/AKT pathway,with low toxicity.Thus,BA might be a potential novel therapeutic agent for CRC.

Impaired PI3K/Akt signal pathway and hepatocellular injury in high-fat fed rats

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.

Roles of the PI3K/Akt pathway in Epstein-Barr virusinduced cancers and therapeutic implications

Viruses have been shown to be responsible for 10%-15% of cancer cases. Epstein-Barr virus(EBV) is the first virus to be associated with human malignancies. EBV can cause many cancers, including Burkett's lymphoma, Hodgkin's lymphoma, post-transplant lymphoproliferative disorders, nasopharyngeal carcinoma and gastric cancer. Evidence shows that phosphoinositide 3-kinase/protein kinase B(PI3K/Akt) plays a key role in EBV-induced malignancies. The main EBV oncoproteins latent membrane proteins(LMP) 1 and LMP2 A can activate the PI3K/Akt pathway, which, in turn, affects cell survival, apoptosis, proliferation and genomic instability via its downstream target proteins to cause cancer. It has also been demonstrated that the activation of the PI3K/Akt pathway can result in drug resistance to chemotherapy. Thus, the inhibition of this pathway can increase the therapeutic efficacy of EBV-associated cancers. For example, PI3 K inhibitor Ly294002 has been shown to increase the effect of 5-fluorouracil in an EBV-associated gastric cancer cell line. At present, dual inhibitors of PI3 K and its downstream target mammalian target of rapamycin have been used in clinical trials and may be included in treatment regimens for EBV-associated cancers.

汉黄芩素调节磷脂酰肌醇3激酶/丝氨酸苏氨酸蛋白激酶/核因子κB信号通路对慢性阻塞性肺疾病大鼠辅助性T细胞17/调节性T细胞平衡的影响

目的探讨汉黄芩素(Wog)调节磷脂酰肌醇3激酶(PI3K)/丝氨酸苏氨酸蛋白激酶(Akt)/核因子κB(NF-κB)信号通路对慢性阻塞性肺疾病(COPD)大鼠辅助性T细胞17(Th17)/调节性T细胞(Treg)平衡的影响。方法2022年8-12月,大鼠采用随机数字表法分为Model组、低剂量Wog组(Wog-L组,50 mg/kg)、高剂量Wog组(Wog-H组,100 mg/kg)、阳性药物氨茶碱组(Ami组,2.3 mg/kg)、IGF-1(PI3K激活剂)组(1.33 mg/kg)、Wog-H+IGF-1组(100 mg/kg+1.33 mg/kg)、对照组(CK组),每组12只。除CK组外,其他组大鼠均需利用烟熏法联合气管滴注脂多糖(LPS)的方法构建COPD模型,建模成功24 h后,进行给药处理,每天1次给药,持续4周。检测呼气峰流量(PEF)、每分钟通气量(MV)、吸气峰流量(PIF);流式细胞术检测外周血中Th17/Treg;HE染色检测肺组织病理;酶联免疫吸附法检测大鼠肺组织中白细胞介素(IL)-17、IL-10水平;蛋白质印迹法检测肺组织中维甲酸相关孤核受体γt(RORγt)、叉头框蛋白P3(Foxp3)、磷酸化PI3K(p-PI3K)、磷酸化Akt(p-Akt)、磷酸化NF-κB p65(p-NF-κB p65)蛋白。结果与CK组比较,Model组大鼠PEF(12.56±0.47比8.72±0.39)、PIF(9.35±0.32比7.24±0.17)、MV(132.26±5.78比96.63±3.28)、Treg(31.18±2.62比15.52±1.01)比例、IL-10(23.35±1.16比8.85±0.27)明显降低(均P<0.05);Th17(3.14±0.13比18.86±1.67)比例、Th17/Treg(0.10±0.01比1.22±0.11)、肺泡间隔(33.36±1.48比49.78±1.73)、气道炎症评分(0比4.56±0.23)及IL-17(75.83±3.60比185.56±8.62)水平明显升高(均P<0.05)。与Model组比较,Wog-L组、Wog-H组PEF(9.66±0.40,11.49±0.51)、PIF(8.28±0.19,9.03±0.22)、MV(105.54±4.11,126.67±5.72)、Treg(19.93±1.18,27.73±2.05)比例、IL-10(11.56±0.33,20.72±0.59)水平明显升高(均P<0.05);Th17(3.14±0.13比18.86±1.67)比例、Th17/Treg(0.10±0.01比1.22±0.11)、肺泡间隔(43.45±1.26,35.78±1.12)、气道炎症评分(3.75±0.17,0.86±0.07)、IL-17(162.27±7.14,103.35±4.33)水平明显降低(均P<0.05)。与CK组比较,Model组大鼠RORγt(0.15±0.01比1.34±0.11)、p-PI3K(0.22±0.01比0.86±0.07)、p-Akt(0.18±0.01比0.75±0.06)、p-NF-κB p65(0.11±0.01比0.69±0.06)蛋白表达升高,Foxp3(1.45±0.27比0.35±0.02)蛋白表达降低(均P<0.05)。与Model组相比,Wog-L组、Wog-H组RORγt(1.08±0.10,0.36±0.02)、p-PI3K(0.71±0.06,0.35±0.03)、p-Akt(0.62±0.06,0.28±0.02)、p-NF-κB p65(0.52±0.05,0.26±0.02)蛋白表达明显降低,Foxp3(0.57±0.04,1.13±0.09)蛋白表达明显升高(均P<0.05)。Wog-H组与Ami组大鼠上述各指标水平近似,均差异无统计学意义(P>0.05)。IGF-1逆转了高剂量Wog对COPD大鼠Th17/Treg的影响。结论Wog促进COPD大鼠Th17/Treg平衡的机制可能与下调PI3K/Akt/NF-κB通路有关。

Tongxinluo Activates PI3K/AKT Signaling Pathway to Inhibit Endothelial Mesenchymal Transition and Attenuate Myocardial Fibrosis after Ischemia-Reperfusion in Mice

Objective To investigate the potential role of Tongxinluo(TXL)in attenuating myocardial fibrosis after myocardial ischemia-reperfusion injury(MIRI)in mice.Methods A MIRI mouse model was established by left anterior descending coronary artery ligation for 45 min.According to a random number table,66 mice were randomly divided into 6 groups(n=11 per group):the sham group,the model group,the LY-294002 group,the TXL group,the TXL+LY-294002 group and the benazepril(BNPL)group.The day after modeling,TXL and BNPL were administered by gavage.Intraperitoneal injection of LY-294002 was performed twice a week for 4 consecutive weeks.Echocardiography was used to measure cardiac function in mice.Masson staining was used to evaluate the degree of myocardial fibrosis in mice.Qualitative and quantitative analysis of endothelial mesenchymal transition(EndMT)after MIRI was performed by immunohistochemistry,immunofluorescence staining and flow cytometry,respectively.The protein expressions of platelet endothelial cell adhesion molecule-1(CD31),α-smoth muscle actin(α-SMA),phosphatidylinositol-3-kinase(PI3K)and phospho protein kinase B(p-AKT)were assessed using Western blot.Results TXL improved cardiac function in MIRI mice,reduced the degree of myocardial fibrosis,increased the expression of CD31 and inhibited the expression ofα-SMA,thus inhibited the occurrence of EndMT(P<0.05 or P<0.01).TXL significantly increased the protein expressions of PI3K and p-AKT(P<0.05 or P<0.01).There was no significant difference between TXL and BNPL group(P>0.05).In addition,the use of the PI3K/AKT pathway-specific inhibitor LY-294002 to block this pathway and combination with TXL intervention,eliminated the protective effect of TXL,further supporting the protective effect of TXL.Conclusion TXL activated the PI3K/AKT signaling pathway to inhibit EndMT and attenuated myocardial fibrosis after MIRI in mice.

蛋白激酶B及其在磷脂酰肌醇3-激酶介导的信号转导中的作用

蛋白激酶B(PKB)是原癌基因c akt的表达产物 ,它参与由生长因子激活的经磷脂酰肌醇 3 激酶 (PI3K)介导的信号转导过程。与许多蛋白激酶相似 ,PKB分子具有一特殊的AH/PH结构域 (AH/PHdomain) ,后者能介导信号分子间的相互作用。PKB是PI3K直接的靶蛋白。PI3K产生的脂类第二信使PI 3,4, P2 和PI 3,4,5 P3等均能与PKB和磷酸肌醇依赖性蛋白激酶 (PDK)的AH/PH结构域结合 ,使二者转位于质膜上并活化。PDK也能使PKB磷酸化而激活 ,激活的PKB又进一步激活抗细胞凋亡机制、葡萄糖代谢 (糖原合成、糖酵解及葡萄糖的摄取 )及蛋白质合成等过程 。

Scorpiones,Scolopendra and Gekko Inhibit Lung Cancer Growth and Metastasis by Ameliorating Hypoxic Tumor Microenvironment via PI3K/AKT/mTOR/HIF-1αSignaling Pathway

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.