Myricetin induces M2 macrophage polarization to alleviate renal tubulointerstitial fibrosis in diabetic nephropathy via PI3K/Akt pathway

BACKGROUND Development of end-stage renal disease is predominantly attributed to diabetic nephropathy(DN).Previous studies have indicated that myricetin possesses the potential to mitigate the pathological alterations observed in renal tissue.Never-theless,the precise molecular mechanism through which myricetin influences the progression of DN remains uncertain.AIM To investigate the effects of myricetin on DN and explore its potential therapeutic mechanism.METHODS Db/db mice were administered myricetin intragastrically on a daily basis at doses of 50 mg/kg or 100 mg/kg for a duration of 12 wk.Subsequently,blood and urine indexes were assessed,along with examination of renal tissue pathology.Kidney morphology and fibrosis were evaluated using various staining techniques including hematoxylin and eosin,periodic acid–Schiff,Masson’s trichrome,and Sirius-red.Additionally,high-glucose culturing was conducted on the RAW 264.7 cell line,treated with 25 mM myricetin or co-administered with the PI3K/Akt inhibitor LY294002 for a period of 24 h.In both in vivo and in vitro settings,quantification of inflammation factor levels was conducted using western blotting,real-time qPCR and ELISA.RESULTS In db/db mice,administration of myricetin led to a mitigating effect on DN-induced renal dysfunction and fibrosis.Notably,we observed a significant reduction in expressions of the kidney injury markers kidney injury molecule-1 and neutrophil gelatinase associated lipocalin,along with a decrease in expressions of inflammatory cytokine-related factors.Furthermore,myricetin treatment effectively inhibited the up-regulation of tumor necrosis factor-alpha,interleukin-6,and interluekin-1βinduced by high glucose in RAW 264.7 cells.Additionally,myricetin modulated the M1-type polarization of the RAW 264.7 cells.Molecular docking and bioinformatic analyses revealed Akt as the target of myricetin.The protective effect of myricetin was nullified upon blocking the polarization of RAW 264.7 via inhibition of PI3K/Akt activation using LY294002.CONCLUSION This study demonstrated that myricetin effectively mitigates kidney injury in DN mice through the regulation of macrophage polarization via the PI3K/Akt signaling pathway.

Downregulation of Serum PTEN Expression in Mercury-Exposed Population and PI3K/AKT Pathway-Induced Inflammation

Objective This study investigated the impact of occupational mercury(Hg) exposure on human gene transcription and expression, and its potential biological mechanisms.Methods Differentially expressed genes related to Hg exposure were identified and validated using gene expression microarray analysis and extended validation. Hg-exposed cell models and PTEN lowexpression models were established in vitro using 293T cells. PTEN gene expression was assessed using qRT-PCR, and Western blotting was used to measure PTEN, AKT, and PI3K protein levels. IL-6 expression was determined by ELISA.Results Combined findings from gene expression microarray analysis, bioinformatics, and population expansion validation indicated significant downregulation of the PTEN gene in the high-concentration Hg exposure group. In the Hg-exposed cell model(25 and 10 μmol/L), a significant decrease in PTEN expression was observed, accompanied by a significant increase in PI3K, AKT, and IL-6 expression.Similarly, a low-expression cell model demonstrated that PTEN gene knockdown led to a significant decrease in PTEN protein expression and a substantial increase in PI3K, AKT, and IL-6 levels.Conclusion This is the first study to report that Hg exposure downregulates the PTEN gene, activates the PI3K/AKT regulatory pathway, and increases the expression of inflammatory factors, ultimately resulting in kidney inflammation.

Extracellular vesicles from iPSC-MSCs alleviate chemotherapy-induced mouse ovarian damage via the ILK-PI3K/AKT pathway

Chemotherapy can significantly reduce follicle counts in ovarian tissues and damage ovarian stroma,causing endocrine disorder,reproductive dysfunction,and primary ovarian insufficiency(POI).Recent studies have suggested that extracellular vesicles(EVs)secreted from mesenchymal stem cells(MSCs)exert therapeutic effects in various degenerative diseases.In this study,transplantation of EVs from human induced pluripotent stem cell-derived MSCs(iPSC-MSC-EVs)resulted in significant restoration of ovarian follicle numbers,improved granulosa cell proliferation,and inhibition of apoptosis in chemotherapy-damaged granulosa cells,cultured ovaries,and in vivo ovaries in mice.Mechanistically,treatment with i PSC-MSC-EVs resulted in up-regulation of the integrinlinked kinase(ILK)-PI3K/AKT pathway,which is suppressed during chemotherapy,most likely through the transfer of regulatory microRNAs(miRNAs)targeting ILK pathway genes.This work provides a framework for the development of advanced therapeutics to ameliorate ovarian damage and POI in female chemotherapy patients.

Expression and correlation of pyroptosis-related markers and PI3K/AKT pathway in endometriosis

Objective:The expression of pyroptosis related factors GSDMD,Caspase-1,NLRP3,IL-1β,IL-18 and PI3K/AKT signaling pathways in ovarian endometriosis was investigated and their correlations analyzed.Methods:A total of 50 patients with endometriosis who underwent ovarian cystectomy in the Department of Gynecology,the First Affiliated Hospital of Bengbu Medical College from January 2022 to January 2023 were enrolled as endometriosis group.In addition,55 patients with normal endometrial tissue who underwent hysteroscopic surgery in the hospital during the same period were selected as the control group,and patients with endometriosis were excluded during the operation.RT-qPCR,Western Blot was used to detect the expression of pyroptosis-related factor and PI3K/AKT signaling pathway mRAN,protein in the above tissues,and the correlation between the expression of the two was analyzed by Pearson correlation test.Results:The expression of pyroptosis-related factors and mRAN of PI3K/AKT signaling pathway in ectopic ovarian cyst tissues was significantly higher than that in the control group,and the difference was statistically significant(P<0.05).Pearson correlation analysis showed that pyroptosis-related factors in ectopic ovarian cysts were positively correlated with the mRNA expression levels of PI3K/AKT signaling pathway(P<0.05).Conclusion:The pyroptosis correlation factors GSDMD,Caspase-1,NLRP3,IL-1β,IL-18 and PI3K/AKT signaling pathways are highly expressed in ovarian endometriosis,and the pyroptosis-related factors are positively correlated with the expression of PI3K/AKT signaling pathway,suggesting that the regulation of endometriosis by activating the PI3K/AKT signaling pathway is likely to be achieved by activating the PI3K/AKT signaling pathway.

TBL1XR1 induces cell proliferation and inhibit cell apoptosis by the PI3K/AKT pathway in pancreatic ductal adenocarcinoma

BACKGROUND Pancreatic ductal adenocarcinoma(PDAC) is one of the deadliest solid tumors. Identification of diagnostic and therapeutic biomarkers for PDAC is urgently needed. Transducin(β)-like 1 X-linked receptor 1(TBL1 XR1) has been linked to the progression of various human cancers. Nevertheless, the function and role of TBL1 XR1 in pancreatic cancers are unclear.AIM To elucidate the function and potential mechanism of TBL1 XR1 in the development of PDAC.METHODS Ninety patients with histologically-confirmed PDAC were included in this study. PDAC tumor samples and cell lines were used to determine the expression of TBL1 XR1. CCK-8 assays and colony formation assays were carried out to assess PDAC cell viability. Flow cytometry was performed to measure the changes in the cell cycle and cell apoptosis. Changes in related protein expression were measured by western blot analysis. Animal analysis was conducted to confirm the impact of TBL1 XR1 in vivo.RESULTS Patients with TBL1 XR1-positive tumors had worse overall survival than those with TBL1 XR1-negative tumors. Moreover, we found that TBL1 XR1 strongly promoted PDAC cell proliferation and inhibited PDAC cell apoptosis. Moreover, knockdown of TBL1 XR1 induced G0/G1 phase arrest. In vivo animal studies confirmed that TBL1 XR1 accelerated tumor cell growth. The results of western blot analysis showed that TBL1 XR1 might play a key role in regulating PDAC cell proliferation and apoptosis via the PI3 K/AKT pathway.CONCLUSION TBL1 XR1 promoted PDAC cell progression and might be an effective diagnostic and therapeutic marker for pancreatic cancer.

Inhibiting PI3K/Akt Pathway Increases DNA Damage of Cervical Carcinoma HeLa Cells by Drug Radiosensitization

This study examined the role of PI3K/Akt pathway in radiosensitization of DNA damage of cervical carcinoma cells.The 50% inhibition concentration(IC50) of cisplatin and docetaxel in HeLa cells was detected by Mono-nuclear cell direct cytotoxicity assay(MTT) in vitro.HeLa cells were treated by cisplatin/docetaxel of 10 percent of IC20 alone or combined with LY294002 for 24 h,and then radiated by different doses of X-ray.The cell survival ratio was obtained by means of clone formation.One-hit multi-target model was fitted to the cell survival curve to calculate dose quasithreshold(Dq),mean lethal dose(D0),2Gy survival fraction(SF2) and sensitization enhancement ratio(SER).The pAkt and total Akt expression was detected by Western blotting and DNA damage by neutro-comet electrophoresis.The HeLa cells were randomly divided into 7 groups in terms of different treatments:Control;radiation treatment(RT) group;LY294002+RT group;cisplatin+RT group;docetaxel+RT group;LY294002+cisplatin+RT group;LY294002+docetaxel+RT group.The apoptosis ratio of each group was measured by flow cytometry.The results showed that docetaxel and cisplatin significantly enhanced the phosphorylation of Akt in radiation-treated HeLa cells.The Dq,D0 and SF2 in LY294002-contained groups were lower than those in docetaxel or cisplatin+RT group.The SER in the LY294002+docetaxel+RT group was 1.35 times that of the docetaxel+RT group,and that in the LY294002+cisplatin+RT group 1.26 times that of the cisplatin+RT group.The Comet electrophoresis showed that tail distance in the LY294002+cisplatin+RT group or LY294002+docetaxel+RT group was longer than in the cisplatin+RT group or docetaxel+RT group.The apoptosis ratio in the LY294002+cisplatin+RT group or LY294002+docetaxel +RT group was higher than in the cisplatin+RT group or docetaxel+RT group.It was concluded that inhibiting PI3K/Akt pathway can increase the effect of docetaxel and cisplatin on the radiosensitivity of HeLa cells and DNA damage resulted from radiation.

Knockdown of DEAD-box 51 inhibits tumor growth of esophageal squamous cell carcinoma via the PI3K/AKT pathway

BACKGROUND Esophageal squamous cell carcinoma(ESCC)is one of the most prevalent malignancies that seriously threaten people’s health worldwide.DEAD-box helicase 51(DDX51)is a member of the DEAD-box(DDX)RNA helicase family,and drives or inhibits tumor progression in multiple cancer types.AIM To determine whether DDX51 affects the biological behavior of ESCC.METHODS The expression of DDX51 in ESCC tumor tissues and adjacent normal tissues was detected by Immunohistochemistry(IHC)analyses and quantitative PCR(qPCR).We knocked down DDX51 in ESCC cell lines by using a small interfering RNA(siRNA)transfection.The proliferation,apoptosis,and mobility of DDX51 siRNAtransfected cells were detected.The effect of DDX51 on the phosphoinositide 3-kinase(PI3K)/AKT pathway was investigated by western blot analysis.A mouse xenograft model was established to investigate the effects of DDX51 knockdown on ESCC tumor growth.RESULTS DDX51 exhibited high expression in ESCC tissues compared with normal tissues and represented a poor prognosis in patients with ESCC.Knockdown of DDX51 induced inhibition of ESCC cell proliferation and promoted apoptosis.Moreover,DDX51 siRNA-expressing cells also exhibited lower migration and invasion rates.Investigations into the underlying mechanisms suggested that DDX51 knock down induced inactivation of the PI3K/AKT pathway,including decreased phosphorylation levels of phosphate and tensin homolog,PI3K,AKT,and mammalian target of rapamycin.Rescue experiments demonstrated that the AKT activator insulin-like growth factor 1 could reverse the inhibitory effects of DDX51 on ESCC malignant development.Finally,we injected DDX51 siRNA-transfected TE-1 cells into an animal model,which resulted in slower tumor growth.CONCLUSION Our study suggests for the first time that DDX51 promotes cancer cell proliferation by regulating the PI3K/AKT pathway;thus,DDX51 might be a therapeutic target for ESCC.

EMP-1 Promotes Tumorigenesis of NSCLC through PI3K/AKT Pathway

This study examined the role of EMP-1 in tumorigenesis of non-small cell lung carcinoma (NSCLC) and the possible mechanism. Specimens were collected from 28 patients with benign lung diseases and 28 with NSCLC, and immunohis to chemically detected to evaluate the correlation of EMP-1 expression to the clinical features of NSCLC. Recombinant adenovirus was constructed to over-express EMP-1 and then infect PC9 cells. Cell proliferation was measured by Ki67 staining. Western blotting was performed to examine the effect of EMP-1 on the PI3K/AKT signaling. Moreover, tumor xeno-grafts were established by subcutaneous injection of PC9 cell suspension (about 5×107/mL in 100 μL of PBS) into the right hind limbs of athymic nude mice. The results showed EMP-1 was significantly up-regulated in NSCLC patients as compared with those with benign lung diseases. Over-expression of EMP-1 promoted proliferation of PC9 cells, which coincided with the activation of the PI3K/AKT pathway. EMP-1 promoted the growth of xenografts of PC9 cells in athymic nude mice. It was concluded that EMP-1 expression may contribute to the development and progress of NSCLC by activating PI3K/AKT pathway.

The basic helix-loop-helix(bHLH)transcription factor,DEC1,provides neuroprotection from apoptosis induced by MPP^+ through PI3K/Akt pathway in SHSY5Y cells

OBJECTIVE To determine the role of the basic helix-loop-helix(b HLH)transcription factor,differentiated embryonic chondrocyte gene 1(DEC1),in the apoptosis induced by 1-methyl-4-phenylpyridiniumion(MPP+)in SH-SY5Y cells.METHODS SH-SY5Y cells were treated with different concentrations of MPP+for 24or 48 h.The cell inhibition and apoptosis were measured by MTT and DAPI staining.DEC1,the apoptosis-related proteins and PI3K/Akt/GSK3β/β-catenin signaling were determined by Western blotting.The expression of DEC1was regulated by overexpression and sh RNA.RESULTS MPP+induces apoptosis along with decreasing of DEC1expression in SH-SY5Y cells.Overexpression or knockdown of DEC1 can alleviate or enhance the cell inhibition induced by MPP+.And overexpression of DEC1 can alleviate the increased cleaved caspase 3/caspase 3 but not alleviate Bax/Bcl-2 induced by MPP+.Meanwhile,MPP+represses PI3Kp110α,p-Akt/Akt,p-GSK-3β/GSK-3βandβ-catenin expression,which is accompanied by decreasing DEC1 expressions.It is confirmed that the activator or inhibitor of PI3K/Akt/GSK-3βpathway can alleviate or enhance the repression of PI3K/Akt/GSK3β/β-catenin signaling cascade induced by MPP+.Further study,we find that overexpression of DEC1 alone can increase PI3Kp110α,p-Akt/Akt,p-GSK-3β/GSK-3β,andβ-catenin expression.More importantly,overexpression of DEC1 significantly alleviates the decreased levels of PI3Kp110α,p-Akt/Akt,p-GSK-3β/GSK-3β,andβ-catenin induced by MPP+.CONCLUSION DEC1 provides neuroprotection from apoptosis induced by MPP+through PI3K/Akt pathway in SH-SY5Y cells.Promisingly,DEC1 is a candidate gene that may provide a novel therapeutic approach for the treatment of Parkinson disease.

Activation of the PI3K/AKT pathway mediates FSH-stimulated VEGF expression in ovarian serous cystadenocarclnoma

There is evidence to suggest that follicle-stimulating hormone （FSH） can facilitate the neovascularization of ovarian cancers by increasing vascular endothelial growth factor （VEGF） expression in cancer cells, although the underlying molecular mechanism of this process is not well known. Therefore, we investigated the effect of FSH on VEGF expression in the ovarian cancer cell lines SKOV-3 and ES-2. Treatment with FSH significantly increased VEGF expression in a dose- and time-dependent manner. In addition, FSH treatment enhanced the expression of survivin and hypoxlainducible factor-1 （HIF-1α）. Knockdown of survivin or HIF-1α suppressed VEGF expression, but only knockdown of survivin inhibited FSH-stimulated VEGF expression. Pretreatment with LY294002, a phosphoinositide 3-kinase （PI3K）/AKT inhibitor, neutralized the enhanced expression of survivin induced by FSH, but treatment with U0126, a mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor, had no such effect. We further showed that ovarian serous cystadenocarcinoma samples had much higher incidence of positive AKT and phosphorylated AKT （pAKT） protein staining than did benign ovarian cystadenoma samples （p 〈 0.01）. The 5-year survival rate was only about 15% in patients with ovarian serous cystadenocarcinoma who had AKT and pAKT expression, whereas it was about 80% in those who did not have AKT or pAKT expression. Taken together, these results indicate that FSH increases the expression of VEGF by upregulating the expression of survivin, which is activated by the PI3K/AKT signaling pathway. Understanding the role of the PI3K/AKT pathway in FSH-stimulated expression of survivin and VEGF will be beneficial for evaluating the prognosis for patients with ovarian serous cystadenocarcinoma and for pursulug effective treatment against this disease.

Macrophage migration inhibitory factor regulates proliferation of gastric cancer cells via the PI3K/Akt pathway

AIM:To investigate the effects of macrophage migration inhibitory factor (MIF) on proliferation of human gastric cancer MGC-803 cells and expression of cyclin D1 and p27Kip1 in them,and further determine whether the effects are related to the PI3K/Akt signal transduction pathway. METHODS:Gastric cancer MGC-803 cells were cultured and then treated with 50 μg/L recombinant human MIF (rhMIF) with and without a PI3K inhibitor,LY294002 (25 μmol/L). MTT assay was used to detect the prolifer-ation of MGC-803 cells. Cell cycle was detected by flow cytometry. Expression of cyclin D1 and p27Kip1 mRNA was by reverse transcription-polymerase chain reaction. Protein expression of phosphorylated Akt (p-Akt),Akt,cyclin D1 and p27Kip1 was examined by immunocyto-chemistry and Western blotting. RESULTS:rhMIF signifi cantly stimulated the prolifera-tion of MGC-803 cells and cell cycle progression from G1 phase to S phase in a concentration-and time-de-pendent manner. After the MGC-803 cells were treated with rhMIF for 24 h,the expression of cyclin D1 was signifi cantly up-regulated compared with the cells not treated with rhMIF at both mRNA and protein levels(0.97 ± 0.02 vs 0.74 ± 0.01,P = 0.002; 0.98 ± 0.05 vs 0.69 ± 0.04,P = 0.003). The p27Kip1 was down-regulated but only statistically significant at the protein level. rhMIF significantly increased the expression of p-Akt,which reached the peak at 30 min,but did not affect the expression of Akt. However,LY294002 inhibited all the effects of rhMIF.CONCLUSION:Macrophage MIF increases the proliferation of gastric cancer cells,induces the expression of cyclin D1 at the transcriptional level and inhibits the expression of p27Kip1 at the post-transcriptional level via the PI3K/Akt pathway.

Involvement of PI3K/Akt Pathway in the Neuroprotective Effect of Sonic Hedgehog on Cortical Neurons under Oxidative Stress

The Sonic hedgehog (SHH) signaling pathway plays a pivotal role in neurogenesis and brain damage repair. Our previous work demonstrated that the SHH signaling pathway was involved in the neuroprotection of cortical neurons against oxidative stress. The present study was aimed to further examine the underlying mechanism. The cortical neurons were obtained from one-day old Sprague-Dawley neonate rats. Hydrogen peroxide (H2O2, 100 μmol/L) was used to treat neurons for 24h to induce oxidative stress. Exogenous SHH (3μg/mL) was employed to activate the SHH pathway, and cyclopamine (20 μmol/L), a specific SHH signal inhibitor, to block SHH pathway. LY294002 (20 μmol/L) were used to pretreat the neurons 30 min before H2O2 treatment and selectively inhibit the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. The cell viability was measured by MTT and apoptosis rate by flow cytometry analysis. The expression of p38, p-p38, ERK, p-ERK, Akt, p-Akt, Bcl-2, and Bax in neurons was detected by immunoblotting. The results showed that as compared with H2O2 treatment, exogenous SHH could increase the expression of p-Akt by 20% and decrease the expression of p-ERK by 33%. SHH exerted no significant effect on p38 mitogen-activated protein kinase (p38 MAPK) pathway. Blockade of PI3K/Akt pathway by LY294002 decreased the cell viability by 17% and increased the cell apoptosis rate by 2-fold. LY294002 treatment could up-regulate the expression of the proapoptotic gene Bax by 12% and down-regulate the expression of the antiapoptotic gene Bcl-2 by 54%. In conclusion, SHH pathway may activate PI3K/Akt pathway and inhibit the activation of the ERK pathway in neurons under oxidative stress. The PI3K/Akt pathway plays a key role in the neuroprotection of SHH. SHH/PI3K/Bcl-2 pathway may be implicated in the protection of neurons against H2O2-induced apoptosis.

Protective Effects of Epigallocatechin-3-gallate on Intestinal Ischemia Reperfusion Injury through Enhanced Activation of PI3K/Akt Pathway in Rats

Inflammation plays a critical role in intestinal ischemia reperfusion injury（IRI）. Epigallocatechin-3-gallate（EGCG） has been demonstrated to possess anti-inflammatory effect. This study examined the effect of EGCG on intestinal IRI and explored the possible mechanisms. Male Wistar rats were randomly divided into three groups： sham-operated group（Sham）, IRI control group（IRI） and IRI-EGCG group（EGCG）. Rats in IRI-EGCG group were administered dissolved EGCG in drinking water（0.4 mg/m L） for 14 days prior to IRI induction. A rat model of intestinal IRI was established by ligating the superior mesenteric artery（SMA） for 30 min, followed by reperfusion for 1 h. Intestinal histology, pro-inflammatory cytokines and mediators were examined and the effect of EGCG on PI3K/Akt signalling was assessed. EGCG significantly alleviated the pathological changes of the intestine and suppressed the IRI-induced up-regulation of TNF-α, IL-1 and IL-6 m RNA and protein expression in the serum and intestine. The mechanism might be that EGCG enhanced the activation of PI3K/Akt signalling pathway. In conclusion, the administration of EGCG can significantly mitigate the acute intestinal IRI in rats by enhancing the activation of PI3K/Akt signalling pathway to suppress inflammatory response and might be a promising alternative for the prevention or treatment of intestinal IRI in the clinical practice.

Pretreatment with Lithospermic Acid Attenuates Oxidative Stress-induced Apoptosis in Bone Marrow-derived Mesenchymal Stem Cells via Anti-oxidation and Activation of PI3K/Akt Pathway

Objective Despite the potential therapeutic approaches of bone marrow-derived mesenchymal stem cells(BMSCs)in orthopaedic,their applications are hampered by harsh oxidative stress conditions after transplantation.In this study,the antiapoptotic and anti-oxidative properties of lithospermic acid(LSA)on BMSCs exposed to hydrogen peroxide(H2O2)were investigated.Methods In the present study,we used H2O2 to induce oxidative injury on BMSCs.Reactive oxygen species(ROS)staining and superoxide dismutase(SOD)assay were performed.The expression levels of phosphorylated(p)-Akt,Bcl-2-associated X protein(Bax)and B-cell lymphoma 2(Bcl-2)were measured by Western blotting.Results LSA can significantly reduce H2O2-induced chromatin condensation and intracellular ROS levels,enhance the activity of SOD.Moreover,it can alleviate H2O2-induced apoptosis by upregulating Bcl-2 and p-Akt,down-regulating Bax,which was blocked by the PI3K inhibitor,LY294002.Conclusions Our results demonstrated that pretreatment with LSA could attenuate oxidative stress-induced apoptosis in BMSCs,which may be related with anti-oxidant properties and partly via modulating PI3K/Akt pathway,suggesting that pharmacologically manipulating BMSCs with LSA could be a promising drug to increase cell survival for BMSCs transplantation in musculoskeletal disorders of orthopaedic.

STMN1 promotes the proliferation and inhibits the apoptosis of acute myeloid leukemiacells by activating the PI3K/Akt pathway

Recent studies have shown that the microtubule disrupting protein Stathmin 1(STMN1)is differentially expressed in AML patients and healthy control.The aim of this study was to explore the effects and molecular mechanism of STMN1 in AML.Here,the expression of STMN1 in peripheral blood cells(PBMCs)and bone marrow of AML patients and healthy volunteers was detected by RT-PCR and Western blot.STMN1 expression was regulated by transfected with STMN1 overexpressed plasmid or shRNA in two human leukemia cell lines K562 and HL60.Cell proliferation was examined by CCK8 and Edu staining.Annexin V and TUNEL assays were applied to test cell apoptosis.Flow cytometry was used to test the cell cycle distribution.The activation of the PI3K signaling pathway and the expression levels of cell cycle and cell apoptosis-related protein were determined by Western blot.In this study,we found that STMN1 was overexpressed in PBMCs and bone marrow of AML patients.STMN1 expression was closely related to FAB subtypes,risk stratification,disease-free survival,and overall survival of AML.Functional assays showed that overexpression of STMN1 in HL60 and K562 cells enhanced cell proliferation,decreased cell apoptosis,and caused G1 phase arrest.In contrast,suppression of STMN1reduced cell proliferation and enhanced cell apoptosis in both HL60 and K562 cells.Moreover,the PI3K/Akt pathway was activated by STMN1,while suppression of STMN1 dysregulated the PI3K/Akt pathway and upregulating the levels of caspases3 and Bax expression.In conclusion,STMN1 was confirmed to promote the proliferation and inhibit the apoptosis of HL60 and K562 cells by modulating the PI3K/Akt pathway.STMN1 might be a novel molecular target for treating AML.

PI3K/Akt pathway is involved in the activation of RAW 264.7 cells induced by hydroxypropyltrimethyl ammonium chloride chitosan

We previously demonstrated that 2-hydroxypropyltrimethyl ammonium chloride chitosan(HACC)promoted the production of nitric oxide(NO)and proinflammatory cytokines by activating the mitogen-activated protein kinases(MAPK)and Janus kinase(JAK)/STAT pathways in RAW 264.7 cells,indicating good immunomodulatory activity of HACC.In this study,to further investigate the immunomodulatory mechanisms of HACC,we determined the roles of phosphatidylinositol 3-kinase(PI3K)/Akt,activating protein(AP-1)and nuclear factor kappa B(NF-κB)in HACC-induced activation of RAW 264.7 cells by the western blotting.The results suggest that HACC promoted the phosphorylation of p85 and Akt.Furthermore,c-Jun and p65 were also increased after the treatment of RAW 264.7 cells with HACC,indicating the translocation of NF-κB and AP-1 from cytoplasm to nucleus.In addition,as scanning electron microscopy(SEM)analysis shows,the cell morphology changed after HACC treatment.These findings indicate that HACC activated MAPK,JAK/STAT,and PI3K/Akt signaling pathways dependent on AP-1 and NF-κB activation in RAW 264.7 cells,ultimately leading to the increase of NO and cytokines.

Thymidylate synthase confers pemetrexed resistance of non-small cell lung cancer cells by EGFR/PI3K/AKT pathway

Chemotherapy drug resistance is the main cause leading to the relapse and metastasis of non-small cell lung cancer(NSCLC)patients.Our study aimed to investigate the mechanism of pemetrexed resistance in NSCLC.Firstly,the pemetrexed(PEM)-resistant PC-9 and A549 lung adenocarcinoma cell lines(PC-9/PEM and A549/PEM)were established.The expression of thymidylate synthase(TS)in PC-9/PEM,A549/PEM,A549,and PC-9 cells were analyzed by qRT-PCR and western blot.Then,cell viability,colony formation,migration,and invasion were performed on PEM-resistant cells transfected with TS siRNA.The role of EGFR in PEM resistance of PEM-resistant cells was investigated using EGFR siRNA.The effects of gefitinib and EGFR siRNA on EGFR/PI3K/AKT pathway and downstream signaling Cyclin D1 and E2F1 in PEM-resistant cells were analyzed.Results showed that the protein level of TS was significantly increased in A549/PEM and PC-9/PEM.TS knockdown inhibited the potency of proliferation,colony-forming potential,migration,and invasion in PEM-resistant cells.EGFR knockdown abrogated the resistance to PEM of PEM-resistant cells and suppressed the migration and invasion of PEM-resistant cells.Gefitinib treatment and EGFR knockdown respectively inhibited the EGFR/PI3K/AKT pathway and downregulated Cyclin D1 and E2F1 in PEM-resistant cells.Thus,TS might be a predictive marker for PEM resistance in NSCLC.Inhibition of the EGFR pathway abrogated the resistance to PEM and inhibited the EGFR/PI3K/AKT and downstream signaling of PEM-resistant NSCLC cell lines.

GDNF Up-Regulates c-Myc Transcription via the PI3K/Akt Pathway to Promote Dairy Goat Male Germline Stem Cells (mGSC) Proliferation

Studies have demonstrated that regulation of GDNF on male germline stem cells （mGSCs） mainly through Ras/Erk1/2, Src family kinase and PI3K/Akt signaling pathways, but the signaling pathways GDNF-mediated are different when the species and cell lines varied. Whether GDNF regulates self-renewal of mGSCs isolated from livestock has not been reported. Here, we purified mGSCs from dairy goat testis using mixed enzymes and fibronectin. Immunofluoresce staining revealed the cultured dairy mGSCs expressed Vasa, Nanos2, Ngn3, Tert, Dazl, Lin28, Oct4, CD49f, Stra8 and GFRa1, reflecting that these cells were mGSCs phenotype. Then we cultured these dairy goat mGSCs in different concentrations of GDNF （0, 5, 10, or 20 ng mL-1） to optimize the best concentration of GDNF to sustain the dairy goat mGSCs self-renewal, after that the inhibitor of PI3K （LY294002, 10 μmol L-1） was added to the medium which contains the optimal concentration of GDNF we obtained by experiments. The mGSCs cultured in different media were compared through the population doubling time （PDT）, capacity of cell proliferation evaluated by PCNA and BrdU immunofluorescence staining, RT-PCR, QRT-PCR, Western blotting and flow cytometry. Results showed that 10 ng mL-1 was the optimal concentration of GDNF to maintain goat mGSCs self-renewal and GDNF up-regulates c-Myc transcription via the PI3K/Akt pathway to promote goat mGSCs proliferation. This study provides us an efficient model to study the mechanism in mGSCs proliferation and differentiation in goat, and has important implications in unveiling signaling pathways in livestock GSCs.

Brucea javanica oil inhibits proliferation of hepatocellular carcinoma cells and induces apoptosis via the PI3K/AKT pathway

Background:Brucea javanica oil(BJO),distributed primarily in Southeast Asia,has long been utilized as a therapeutic agent for treating malignancies.However,its anticancer mechanisms are not clearly understood.The objective of this study was to examine the mechanisms underlying its treatment of hepatocellular carcinoma cells.Methods:CCK8 assay was used to evaluate cell viability.Hoechst33342 staining and flow cytometry analyses were used to examine apoptosis.Mito-Tracker Red CMXRos kit was used to measure the membrane potential of mitochondria.ATP assay kit was used to evaluate ATP levels.Western blots were used to assess the presence of AKT,adenosine monophosphate-activated protein kinase,Caspase3,Caspase9,Bax,and Bcl-2.Results:BJO inhibited the proliferation of hepatocellular carcinoma cells HepG2 in a time-and dose-dependent manner.It induced apoptosis,with the percentage of cells treated with 50–150μg/mL BJO increasing from 8.01%to 28.02%in a concentration-dependent manner(P<0.05,when 50μg/mL of BJO group compared with the control group;P<0.001,when 100 or 150μg/mL of BJO group compared with the control group).After exposed to BJO,the expression of C-caspase3,C-caspase9 and Bax upregulated while that of Bcl-2 downregulated.BJO suppressed the PI3K/AKT pathway and promoted phosphorylation of adenosine monophosphate-activated protein kinase,while repressing the phosphorylation of mechanistic target of rapamycin.Compared with treatment by BJO alone,the PI3K/AKT agonist 740Y-P increased the survival rate of HepG2 cells(P<0.01)and attenuated the inhibitory effect of BJO on cell apoptosis(P<0.05).Conclusion:BJO is capable of inhibiting proliferation of HepG2 cells and inducing apoptosis via the PI3K/AKT pathway.

Achyranthes bidentata polypeptide k attenuates neuroinflammation by inhibiting PI3K/Akt pathway and promoting Nrf2 translocation in BV-2 microglia

Activated microglia play a critical role in regulating neuroinflammatory responses in central nervous system.Previous studies have shown that Ach yranthes bidentata polypeptide k's(ABPPk s)neuroprotective effects are partly due to its anti-inflammatory effect,but the mechanism remains unknown.Here we investigated the anti-inflam matory effects of ABPPk on LPSactivated BV2 microglia.The results showed that pretreated with ABPPk(0.2-5μg/mL)for 30 minutes reduced the iNOS mediated NO and COX-2 mediated PGE2 production significantly in LPS-activated BV2 microglia.ABPPk(1 and 5μg/mL)also suppressed the production of TNF-α,IL-6,glutamate and ROS significantly.