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
The mammalian target of rapamycin(mTOR)acts in two structurally and functionally distinct protein complexes,mTOR complex 1(mTORC1)and mTOR complex 2(mTORC2).Upon deregulation,activated mTOR signaling is associated wit...The mammalian target of rapamycin(mTOR)acts in two structurally and functionally distinct protein complexes,mTOR complex 1(mTORC1)and mTOR complex 2(mTORC2).Upon deregulation,activated mTOR signaling is associated with multiple processes involved in tumor growth and metastasis.Compared with mTORC1,much less is known about mTORC2 in cancer,mainly because of the unavailability of a selective inhibitor.However,existing data suggest that mTORC2 with its two distinct subunits Rictor and mSin1 might play a more important role than assumed so far.It is one of the key effectors of the PI3K/AKT/mTOR pathway and stimulates cell growth,cell survival,metabolism,and cytoskeletal organization.It is not only implicated in tumor progression,metastasis,and the tumor microenvironment but also in resistance to therapy.Rictor,the central subunit of mTORC2,was found to be upregulated in different kinds of cancers and is associated with advanced tumor stages and a bad prognosis.Moreover,AKT,the main downstream regulator of mTORC2/Rictor,is one of the most highly activated proteins in cancer.Primary and secondary liver cancer are major problems for current cancer therapy due to the lack of specific medical treatment,emphasizing the need for further therapeutic options.This review,therefore,summarizes the role of mTORC2/Rictor in cancer,with special focus on primary liver cancer but also on liver metastases.展开更多
Inflammatory bowel diseases(IBDs),with blurred etiology,show a rising trend and are of global concern.Of various factors involved in IBD pathogenesis and development,inflammation has been shown to play a major role.Re...Inflammatory bowel diseases(IBDs),with blurred etiology,show a rising trend and are of global concern.Of various factors involved in IBD pathogenesis and development,inflammation has been shown to play a major role.Recognition of the molecular and cellular pathways that induce IBD is an emerging subject to develop targeted therapies.Mammalian target of rapamycin(mTOR)is one the most common receptors of many inflammatory pathways,including that of IBD.To this end,we intend to overview the mTOR inhibitors for their possible efficacy in present and future approaches to treatment of IBD.展开更多
AIM:To elucidate the effect of rapamycin on regulating the production of interleukin(IL)-1β in Aspergillus fumigatus(A.fumigatus)-induced keratitis and to verify whether the expression of IL-1β in A.fumigatus kerati...AIM:To elucidate the effect of rapamycin on regulating the production of interleukin(IL)-1β in Aspergillus fumigatus(A.fumigatus)-induced keratitis and to verify whether the expression of IL-1β in A.fumigatus keratitis is associated with the mammalian target of rapamycin(mT OR)/Toll-like receptor 4(TLR4) signaling pathway.METHODS:Fungal keratitis mouse models of susceptible C57 BL/6 mice were established using A.fumigatus.The mice were subsequently treated with rapamycin.The protein levels of p-mT OR,TLR4,and IL-1β in normal and infected corneal tissue were measured by Western blot.The TLR4 and IL-1β m RNA levels were determined by real-time polymerase chain reaction(PCR).RESULTS:In C57 BL/6 mice,rapamycin treatment decreased the clinical scores and production of the pro-inflammatory cytokine,IL-1β.The expression of TLR4,stimulated by A.fumigatus,was reduced as well when the mT OR signaling pathway was suppressed by rapamycin.CONCLUSION:Rapamycin is beneficial for the outcome of fungal keratitis and has an inhibitory effect expression of the inflammatory cytokine IL-1β.The inhibitory effect on IL-1β expression can be associated with the mT OR/TLR4 signaling pathway in A.fumigatus infection in mice.展开更多
BACKGROUND With continuous advancement of industrial society,environmental pollution has become more and more serious.There has been an increase in infertility caused by environmental factors.Nonylphenol(NP)is a stabl...BACKGROUND With continuous advancement of industrial society,environmental pollution has become more and more serious.There has been an increase in infertility caused by environmental factors.Nonylphenol(NP)is a stable degradation product widely used in daily life and production and has been proven to affect male fertility.However,the underlying mechanisms therein are unclear.Thus,it is necessary to study the effect and mechanism of NP on spermatogonial stem cells(SSCs).AIM To investigate the cytotoxic effect of NP on SSCs via the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/AKT/mTOR)pathway.METHODS SSCs were treated with NP at 0,10,20 or 30μmol.MTT assay was performed to evaluate the effect of NP on the proliferation of SSCs.Flow cytometry was conducted to measure SSC apoptosis.The expression of Bad,Bcl-2,cytochrome-c,pro-Caspase 9,SOX-2,OCT-4,Nanog,Nanos3,Stra8,Scp3,GFRα1,CD90,VASA,Nanos2,KIT,PLZF and PI3K/AKT/mTOR-related proteins was observed by western blot,and the mRNA expression of SOX-2,OCT-4 and Nanog was detected by quantitative reverse transcription polymerase chain reaction.RESULTS Compared with untreated cells(0μmol NP),SSCs treated with NP at all concentrations showed a decrease in cell proliferation and expression of Bcl-2,Nanog,OCT-4,SOX-2,Nanos3,Stra8,Scp3,GFRα1,CD90,VASA,Nanos2,KIT,and PLZF(P<0.05),whereas the expression of Bad,cytochrome-c,and pro-Caspase 9 increased significantly(P<0.05).We further examined the PI3K/AKT/mTOR pathway and found that the phosphorylation of PI3K,AKT,mTORC1,and S6K was significantly decreased by NP at all concentrations compared to that in untreated SSCs(P<0.05).NP exerted the greatest effect at 30μmol among all NP concentrations.CONCLUSION NP attenuated the proliferation,differentiation and stemness maintenance of SSCs while promoting apoptosis and oxidative stress.The associated mechanism may be related to the PI3K/AKT/mTOR pathway.展开更多
BACKGROUND Colorectal cancer has a low 5-year survival rate and high mortality.Humanβ-defensin-1(hBD-1)may play an integral function in the innate immune system,contributing to the recognition and destruction of canc...BACKGROUND Colorectal cancer has a low 5-year survival rate and high mortality.Humanβ-defensin-1(hBD-1)may play an integral function in the innate immune system,contributing to the recognition and destruction of cancer cells.Long non-coding RNAs(lncRNAs)are involved in the process of cell differentiation and growth.AIM To investigate the effect of hBD-1 on the mammalian target of rapamycin(mTOR)pathway and autophagy in human colon cancer SW620 cells.METHODS CCK8 assay was utilized for the detection of cell proliferation and determination of the optimal drug concentration.Colony formation assay was employed to assess the effect of hBD-1 on SW620 cell proliferation.Bioinformatics was used to screen potentially biologically significant lncRNAs related to the mTOR pathway.Additionally,p-mTOR(Ser2448),Beclin1,and LC3II/I expression levels in SW620 cells were assessed through Western blot analysis.RESULTS hBD-1 inhibited the proliferative ability of SW620 cells,as evidenced by the reduction in the colony formation capacity of SW620 cells upon exposure to hBD-1.hBD-1 decreased the expression of p-mTOR(Ser2448)protein and increased the expression of Beclin1 and LC3II/I protein.Furthermore,bioinformatics analysis identified seven lncRNAs(2 upregulated and 5 downregulated)related to the mTOR pathway.The lncRNA TCONS_00014506 was ultimately selected.Following the inhibition of the lncRNA TCONS_00014506,exposure to hBD-1 inhibited p-mTOR(Ser2448)and promoted Beclin1 and LC3II/I protein expression.CONCLUSION hBD-1 inhibits the mTOR pathway and promotes autophagy by upregulating the expression of the lncRNA TCONS_00014506 in SW620 cells.展开更多
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 st...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.展开更多
Sodium-coupled neutral amino acid transporter 2(SNAT2),also known as solute carrier family 38 member 2(SLC38 A2),is expressed in the skeletal muscle.Our research previously indicated that SNAT2 m RNA expression level ...Sodium-coupled neutral amino acid transporter 2(SNAT2),also known as solute carrier family 38 member 2(SLC38 A2),is expressed in the skeletal muscle.Our research previously indicated that SNAT2 m RNA expression level in the skeletal muscle was modulated by genotype and dietary protein.The aim of this study was to investigate the key role of the amino acid transporter SNAT2 in muscle cell growth,differentiation,and related signaling pathways via SNAT2 suppression using the inhibitor a-methylaminoisobutyric acid(Me AIB).The results showed that SNAT2 suppression down-regulated both the m RNA and protein expression levels of SNAT2 in C2 C12 cells,inhibited cell viability and differentiation of the cell,and regulated the cell distribution in G0/G1 and S phases(P<0.05).Meanwhile,most of the intercellular amino acid content of the cells after Me AIB co-culturing was significantly lower(P<0.05).Furthermore,the m RNA expression levels of system L amino acid transporter 1(LAT1),silent information regulator 1,and peroxisome proliferator-activated receptor-gamma co-activator 1 alpha,as well as the protein expression levels of amino acid transporters LAT1 and vacuolar protein sorting 34,were all down-regulated.The phosphorylated protein expression levels of mammalian target of rapamycin(m TOR),regulatory-associated protein of m TOR,4 E binding protein 1,and ribosomal protein S6 kinase 1 after Me AIB treatment were also significantly down-regulated(P<0.05),which could contribute to the importance of SNAT2 in amino acid transportation and skeletal muscle cell sensing.In conclusion,SNAT2 suppression inhibited C2 C12 cell growth and differentiation,as well as the availability of free amino acids.Although the m TOR complex 1 signaling pathway was found to be involved,its response to different nutrients requires further study.展开更多
Objective This study aimed to investigate the effects of the peroxisome proliferator-activated receptorδ(PPARδ)agonist GW501516 on the proliferation of pulmonary artery smooth muscle cells(PASMCs)induced by hypoxia,...Objective This study aimed to investigate the effects of the peroxisome proliferator-activated receptorδ(PPARδ)agonist GW501516 on the proliferation of pulmonary artery smooth muscle cells(PASMCs)induced by hypoxia,in order to search for new drugs for the treatment and prevention of pulmonary vascular remodeling.Methods PASMCs were incubated with different concentrations of GW501516(10,30,100 nmol/L)under the hypoxic condition.The proliferation was determined by a CCK-8 assay.The cell cycle progression was analyzed by flow cytometry.The expression of PPARδ,S phase kinase-associated protein 2(Skp2),and cell cycle-dependent kinase inhibitor p27 was detected by Western blotting.Then PASMCs were treated with 100 nmol/L GW501516,100 nmol/L mammalian target of rapamycin(mTOR)inhibitor rapamycin and/or 2µmol/L mTOR activator MHY1485 to explore the molecular mechanisms by which GW501516 reduces the proliferation of PASMCs.Results The presented data demonstrated that hypoxia reduced the expression of PPARδin an oxygen concentration-and time-dependent manner,and GW501516 decreased the proliferation of PASMCs induced by hypoxia by blocking the progression through the G0/G1 to S phase of the cell cycle.In accordance with these findings,GW501516 downregulated Skp2 and upregulated p27 in hypoxia-exposed PASMCs.Further experiments showed that rapamycin had similar effects as GW501516 in inhibiting cell proliferation,arresting the cell cycle,regulating the expression of Skp2 and p27,and inactivating mTOR in hypoxia-exposed PASMCs.Moreover,MHY1485 reversed all the beneficial effects of GW501516 on hypoxia-stimulated PASMCs.Conclusion GW501516 inhibited the proliferation of PASMCs induced by hypoxia through blocking the mTOR/Skp2/p27 signaling pathway.展开更多
Background:Autophagy dysfunction plays a crucial role in tau accumulation and neurodegeneration in Alzheimer’s disease(AD).This study aimed to investigate whether and how the accumulating tau may in turn affect autop...Background:Autophagy dysfunction plays a crucial role in tau accumulation and neurodegeneration in Alzheimer’s disease(AD).This study aimed to investigate whether and how the accumulating tau may in turn affect autophagy.Methods:The primary hippocampal neurons,N2a and HEK293T cells with tau overexpression were respectively starved and treated with vinblastine to study the effects of tau on the initiating steps of autophagy,which was analysed by Student’s two-tailed t-test.The rapamycin and concanamycin A were employed to inhibit the mammalian target of rapamycin kinase complex 1(mTORC1)activity and the vacuolar H+-ATPase(v-ATPase)activity,respectively,which were analysed by One-way ANOVA with post hoc tests.The Western blotting,co-immunoprecipitation and immunofuorescence staining were conducted to gain insight into the mechanisms underlying the tau effects of mTORC1 signaling alterations,as analysed by Student’s two-tailed t-test or One-way ANOVA with post hoc tests.The autophagosome formation was detected by immunofuorescence staining and transmission electron microscopy.The amino acids(AA)levels were detected by high performance liquid chromatography(HPLC).Results:We observed that overexpressing human full-length wild-type tau to mimic AD-like tau accumulation induced autophagy deficits.Further studies revealed that the increased tau could bind to the prion-related domain of T cell intracellular antigen 1(PRD-TIA1)and this association significantly increased the intercellular level of amino acids(Leucine,P=0.0038;Glutamic acid,P=0.0348;Alanine,P=0.0037;Glycine,P=0.0104),with concordant upregulation of mTORC1 activity[phosphorylated eukaryotic translation initiation factor 4E-binding protein 1(p-4EBP1),P<0.0001;phosphorylated 70 kD ribosomal protein S6 kinase 1(p-p70S6K1),P=0.0001,phosphorylated unc-51-like autophagyactivating kinase 1(p-ULK1),P=0.0015]and inhibition of autophagosome formation[microtubuleassociated protein light chain 3 II(LC3 II),P=0.0073;LC3 puncta,P<0.0001].As expected,this tau-induced deficit of autophagosome formation in turn aggravated tau accumulation.Importantly,we also found that blocking TIA1 and tau interaction by overexpressing PRD-TIA1,downregulating the endogenous TIA1 expression by shRNA,or downregulating tau protein level by a small proteolysis targeting chimera(PROTAC)could remarkably attenuate tau-induced autophagy impairment.Conclusions:Our findings reveal that AD-like tau accumulation inhibits autophagosome formation and induces autophagy deficits by activating the TIA1/amino acid/mTORC1 pathway,and thus this work reveals new insight into tau-associated neurodegeneration and provides evidence supporting the use of new therapeutic targets for AD treat-ment and that of related tauopathies.展开更多
BACKGROUND Alzheimer’s disease(AD)is the most common neurodegenerative disorder,and there are currently no effective drugs to delay progression of the disease.Ferroptosis may play a vital part in AD,and is therefore ...BACKGROUND Alzheimer’s disease(AD)is the most common neurodegenerative disorder,and there are currently no effective drugs to delay progression of the disease.Ferroptosis may play a vital part in AD,and is therefore receiving increasing attention by researchers.AIM To investigate the effects of dexmedetomidine(Dex)on ferroptosis in AD mouse hippocampus.METHODS Hippocampal neurons(HNs)HT22 were induced by amyloidβ-protein(Aβ)and both in vitro and in vivo AD mouse models were prepared via injections.The cellcounting kit-8 assay and immunofluorescence technique were adopted to determine cell proliferation activity and intracellular Fe2+levels,and the TBA method and microplate method were employed for malondialdehyde and glutathione measurements,respectively.Hippocampal tissue damage was determined using hematoxylin and eosin and Nissl staining.Mouse learning and memory ability in each group was assessed by the Morris water maze test,and the expression levels of mammalian target of rapamycin(mTOR)signal molecules and ferroptosis-related proteins transferrin receptor 1(TFR1),SLC7A11 and glutathione peroxidase 4 were examined by western blotting.RESULTS Dex enhanced lipid peroxidation and iron influx in mouse HNs in both in vitro and in vivo experiments,while inhibition of the mTOR axis blocked this process.These findings demonstrate that Dex can inhibit ferroptosis-induced damage in mouse HNs by activating mTOR-TFR1 signaling to regulate ferroptosis-associated proteins,thus alleviating cognitive dysfunction in AD mice.CONCLUSION Dex can activate the mTOR-TFR1 axis to inhibit ferroptosis in mouse HNs,thereby improving the learning and memory ability of mice.展开更多
Defects in autophagy-mediated clearance of α-synuclein may be one of the key factors leading to progressive loss of dopaminergic neurons in the substantia nigra. Moxibustion therapy for Parkinson's disease has be...Defects in autophagy-mediated clearance of α-synuclein may be one of the key factors leading to progressive loss of dopaminergic neurons in the substantia nigra. Moxibustion therapy for Parkinson's disease has been shown to have a positive effect, but the underlying mechanism remains unknown. Based on this, we explored whether moxibustion could protect dopaminergic neurons by promoting autophagy mediated by mammalian target of rapamycin(m TOR), with subsequent elimination of α-syn. A Parkinson's disease model was induced in rats by subcutaneous injection of rotenone at the back of their necks, and they received moxibustion at Zusanli(ST36), Guanyuan(CV4) and Fengfu(GV16), for 10 minutes at every point, once per day, for 14 consecutive days. Model rats without any treatment were used as a sham control. Compared with the Parkinson's disease group, the moxibustion group showed significantly greater tyrosine hydroxylase immunoreactivity and expression of light chain 3-Ⅱ protein in the substantia nigra, and their behavioral score, α-synuclein immunoreactivity, the expression of phosphorylated m TOR and phosphorylated ribosomal protein S6 kinase(p-p70S6K) in the substantia nigra were significantly lower. These results suggest that moxibustion can promote the autophagic clearance of α-syn and improve behavioral performance in Parkinson's disease model rats. The protective mechanism may be associated with suppression of the m TOR/p70S6K pathway.展开更多
AIM: To evaluate the expression of serum fibrosis markers in liver transplantation(LT) recipients on everolimus monotherapy compared to patients on an anti-calcineurin regimen.METHODS: This cross-sectional case-contro...AIM: To evaluate the expression of serum fibrosis markers in liver transplantation(LT) recipients on everolimus monotherapy compared to patients on an anti-calcineurin regimen.METHODS: This cross-sectional case-control study included LT patients on everolimus monotherapy(cases)(E)(n = 30) and matched controls on an anticalcineurin regimen(calcineurin inhibitors, CNI), paired by etiology of liver disease and time since LT(n = 30). Clinical characteristics, blood tests and elastography were collected. Serum levels of transforming growth factor-β(TGF-β), angiopoietin-1, tumor necrosis factor(TNF), platelet derived growth factor, amino-terminal propeptide of type Ⅲ procollagen(PⅢNP), hyaluronicacid(HA), VCM-1(ng/m L), interleukin(IL)-10, interferoninducible protein 10(IP-10), vascular endothelial growth factor and hepatocyte growth factor(HGF)(pg/m L) were determined by enzyme-linked immunosorbent assay. Expression of these markers between E and CNI was compared. Stratified analysis was done according to factors that may influence liver fibrosis. Variables are described with medians(interquartillic range) or percentages.RESULTS: A total of 60 patients [age: 59(49-64), hepatitis C virus(HCV): n = 21(35%), time from LT: 73 mo(16-105)] were included. Patients had been on everolimus for a median of 15 mo. No differences in inflammatory activity, APRI test or liver elastography were found between the groups. No significant differences were observed between the groups in serum levels of PⅢ NP, metalloproteinase type = 1, angiopoietin, HGF, IP-10, TNF-α, IL-10 and vascular cell adhesion molecule. Patients on E had a lower expression of TGF-β [E: 12.7(3.7-133.6), CNI: 152.5(14.4-333.2), P = 0.009] and HA [E: 702.89(329.4-838.2), CNI: 1513.6(691.9-1951.4), P = 0.001] than those on CNI. This difference was maintained in the stratified analysis when recipient age is more than 50 years(TFG-β1: P = 0.06; HA: P = 0.005), in patients without active neoplasia(TFG-β1, P = 0.009; HA: P = 0.01), according to time since LT(> than 5 years, TFG-β1: P = 0.001; HA: P = 0.002), related to previous history of biliary complications(HA: P = 0.01) and HCV recurrence(HA: P = 0.004). Liver transplant recipients with everolimus monotherapy had less serum expression of TGF-β y HA than matched patients with anti-calcineurins. This difference remains when classifying patients according to donor age and time since LT. Due to the small sample size, when examining patients with a prior history of biliary complications or recurrent HCV, the difference was nonsignificant but trends towards the lower expression of TFG-β1 in the everolimus group. Mammalian target of rapamycin(m TOR) plays a role in the transformation of quiescent hepatocellular stellate cell to their activeprofibrotic state, and experimental models have demonstrated the potential activity of m TOR inhibition in attenuating fibrogenesis.CONCLUSION: This study supports a possible role of everolimus in liver fibrosis modulation after LT in a clinical setting and suggests that tailoring immunosuppression could avoid fibrosis progression in the allograft.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
The prevalence of type 2 diabetes(T2D)continues to rise despite the amount of research dedicated to finding the culprits of this debilitating disease.Skeletal muscle is arguably the most important contributor to gluco...The prevalence of type 2 diabetes(T2D)continues to rise despite the amount of research dedicated to finding the culprits of this debilitating disease.Skeletal muscle is arguably the most important contributor to glucose disposal making it a clear target in insulin resistance and T2D research.Within skeletal muscle there is a clear link to metabolic dysregulation during the progression of T2D but the determination of culprits vs consequences of the disease has been elusive.Emerging evidence in skeletal muscle implicates influential cross talk between a key anabolic regulatory protein,the mammalian target of rapamycin(mTOR)and its associated complexes(mTORC1 and mTORC2),and the well-described canonical signaling for insulin-stimulated glucose uptake.This new understanding of cellular signaling crosstalk has blurred the lines of what is a culprit and what is a consequence with regard to insulin resistance.Here,we briefly review the most recent understanding of insulin signaling in skeletal muscle,and how anabolic responses favoring anabolism directly impact cellular glucose disposal.This review highlights key cross-over interactions between protein and glucose regulatory pathways and the implications this may have for the design of new therapeutic targets for the control of glucoregulatory function in skeletal muscle.展开更多
Alzheimer’s disease(AD)is the most common reason for progressive dementia in the elderly.It has been shown that disorders of the mammalian/mechanistic target of rapamycin(mTOR)signaling pathways are related to the AD...Alzheimer’s disease(AD)is the most common reason for progressive dementia in the elderly.It has been shown that disorders of the mammalian/mechanistic target of rapamycin(mTOR)signaling pathways are related to the AD.On the other hand,diabetes mellitus(DM)is a risk factor for the cognitive dysfunction.The pathogenesis of the neuronal impairment caused by diabetic hyperglycemia is intricate,which contains neuro-inflammation and/or neurodegeneration and dementia.Glucagon-like peptide-1(GLP1)is interesting as a possible link between metabolism and brain impairment.Modulation of GLP1 activity can influence amyloid-beta peptide aggregation via the phosphoinositide-3 kinase/AKT/mTOR signaling pathway in AD.The GLP1 receptor agonists have been shown to have favorable actions on the brain such as the improvement of neurological deficit.They might also exert a beneficial effect with refining learning and memory on the cognitive impairment induced by diabetes.Recent experimental and clinical evidence indicates that dipeptidyl-peptidase-4(DPP4)inhibitors,being currently used for DM therapy,may also be effective for AD treatment.The DPP-4 inhibitors have demonstrated neuroprotection and cognitive improvements in animal models.Although further studies for mTOR,GLP1,and DPP4 signaling pathways in humans would be intensively required,they seem to be a promising approach for innovative AD-treatments.We would like to review the characteristics of AD pathogenesis,the key roles of mTOR in AD and the preventive and/or therapeutic suggestions of directing the mTOR signaling pathway.展开更多
Objective Intrauterine growth restriction followed by postnatal catch-up growth(CG-IUGR)increases the risk of insulin resistance-related diseases.Low-density lipoprotein receptor-related protein 6(LRP6)plays a substan...Objective Intrauterine growth restriction followed by postnatal catch-up growth(CG-IUGR)increases the risk of insulin resistance-related diseases.Low-density lipoprotein receptor-related protein 6(LRP6)plays a substantial role in glucose metabolism.However,whether LRP6 is involved in the insulin resistance of CG-IUGR is unclear.This study aimed to explore the role of LRP6 in insulin signaling in response to CG-IUGR.Methods The CG-IUGR rat model was established via a maternal gestational nutritional restriction followed by postnatal litter size reduction.The mRNA and protein expression of the components in the insulin pathway,LRP6/β-catenin and mammalian target of rapamycin(mTOR)/S6 kinase(S6K)signaling,was determined.Liver tissues were immunostained for the expression of LRP6 andβ-catenin.LRP6 was overexpressed or silenced in primary hepatocytes to explore its role in insulin signaling.Results Compared with the control rats,CG-IUGR rats showed higher homeostasis model assessment for insulin resistance(HOMA-IR)index and fasting insulin level,decreased insulin signaling,reduced mTOR/S6K/insulin receptor substrate-1(IRS-1)serine307 activity,and decreased LRP6/β-catenin in the liver tissue.The knockdown of LRP6 in hepatocytes from appropriate-for-gestational-age(AGA)rats led to reductions in insulin receptor(IR)signaling and mTOR/S6K/IRS-1 serine307 activity.In contrast,LRP6 overexpression in hepatocytes of CG-IUGR rats resulted in elevated IR signaling and mTOR/S6K/IRS-1 serine307 activity.Conclusion LRP6 regulated the insulin signaling in the CG-IUGR rats via two distinct pathways,IR and mTOR-S6K signaling.LRP6 may be a potential therapeutic target for insulin resistance in CG-IUGR individuals.展开更多
BACKGROUND Mesenchymal stem cells(MSCs)are a type of stem cells that possess relevant regenerative abilities and can be used to treat many chronic diseases.Diabetes mellitus(DM)is a frequently diagnosed chronic diseas...BACKGROUND Mesenchymal stem cells(MSCs)are a type of stem cells that possess relevant regenerative abilities and can be used to treat many chronic diseases.Diabetes mellitus(DM)is a frequently diagnosed chronic disease characterized by hyperglycemia which initiates many multisystem complications in the long-run.DM patients can benefit from MSCs transplantation to curb down the pathological consequences associated with hyperglycemia persistence and restore the function of damaged tissues.MSCs therapeutic outcomes are found to last for short period of time and ultimately these regenerative cells are eradicated and died in DM disease model.AIM To investigate the impact of high glucose or hyperglycemia on the cellular and molecular characteristics of MSCs.METHODS Human adipose tissue-derived MSCs(hAD-MSCs)were seeded in low(5.6 mmol/L of glucose)and high glucose(25 mmol/L of glucose)for 7 d.Cytotoxicity,viability,mitochondrial dynamics,and apoptosis were deplored using specific kits.Western blotting was performed to measure the protein expression of phosphatidylinositol 3-kinase(PI3K),TSC1,and mammalian target of rapamycin(mTOR)in these cells.RESULTS hAD-MSCs cultured in high glucose for 7 d demonstrated marked decrease in their viability,as shown by a significant increase in lactate dehydrogenase(P<0.01)and a significant decrease in Trypan blue(P<0.05)in these cells compared to low glucose control.Mitochondrial membrane potential,indicated by tetramethylrhodamine ethyl ester(TMRE)fluorescence intensity,and nicotinamide adenine dinucleotide(NAD+)/NADH ratio were significantly dropped(P<0.05 for TMRE and P<0.01 for NAD+/NADH)in high glucose exposed hAD-MSCs,indicating disturbed mitochondrial function.PI3K protein expression significantly decreased in high glucose culture MSCs(P<0.05 compared to low glucose)and it was coupled with significant upregulation in TSC1(P<0.05)and downregulation in mTOR protein expression(P<0.05).Mitochondrial complexes I,IV,and V were downregulated profoundly in high glucose(P<0.05 compared to low glucose).Apoptosis was induced as a result of mitochondrial impairment and explained the poor survival of MSCs in high glucose.CONCLUSION High glucose impaired the mitochondrial dynamics and regulatory proteins in hAD-MSCs ensuing their poor survival and high apoptosis rate in hyperglycemic microenvironment.展开更多
Although multiple advances have been made in systemic therapy for renal cell carcinoma(RCC),metastatic RCC remains incurable.In the current review,we focus on the underlying biology of RCC and plausible mechanisms of ...Although multiple advances have been made in systemic therapy for renal cell carcinoma(RCC),metastatic RCC remains incurable.In the current review,we focus on the underlying biology of RCC and plausible mechanisms of metastasis.We further outline evolving strategies to combat metastasis through adjuvant therapy.Finally,we discuss clinical patterns of metastasis in RCC and how distinct systemic therapy approaches may be considered based on the anatomic location of metastasis.展开更多
Objective Ticagrelor is a widely used anti-platelet drug.However,the mechanisms by which ticagrelor protects against sepsis-induced acute kidney injury(AKI)have not been clearly demonstrated.We designed this study to ...Objective Ticagrelor is a widely used anti-platelet drug.However,the mechanisms by which ticagrelor protects against sepsis-induced acute kidney injury(AKI)have not been clearly demonstrated.We designed this study to explore the protective effect of ticagrelor on sepsis-induced AKI and to explore the underlying mechanisms.Methods C57BL6J mice received oral ticagrelor(20 mg/kg and 50 mg/kg)for 7 days,and then caecal ligation and puncture(CLP)were performed.An adenosine receptor antagonist,CGS15943,was administered(10 mg/kg,intraperitoneal injection)to block the adenosine pathway 2 h before CLP.After 24 h,serum creatinine levels were measured.Periodic acid-Schiff(PAS)staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL)staining were employed to analyze pathological changes and cell apoptosis.Serum concentrations of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),and mRNA expression of tissue TNF-αand IL-1βwere detected.Western blotting analysis was used to determine AKT and mammalian target of rapamycin(mTOR)protein expression in the kidney.Results PAS staining showed less swelling of renal tubules,and TUNEL staining revealed less cell apoptosis in the ticagrelor group than in the CLP group.Serum creatinine levels were significantly lower in the ticagrelor group than in the CLP group.Moreover,significantly lower serum and kidney levels of TNF-αand IL-1βwere observed in the ticagrelor group.CGS15943 blocked the effects of ticagrelor.Western blotting analysis showed increased phosphorylation of AKT and mTOR in the kidneys of the 50 mg/kg ticagrelor group.The adenosine receptor antagonist inhibited the activation of AKT and mTOR.Conclusion This study demonstrates that the protective effect of ticagrelor on sepsis-induced AKI depends on adenosine receptor activation and the subsequent increase of AKT and mTOR phosphorylation.展开更多
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.
文摘The mammalian target of rapamycin(mTOR)acts in two structurally and functionally distinct protein complexes,mTOR complex 1(mTORC1)and mTOR complex 2(mTORC2).Upon deregulation,activated mTOR signaling is associated with multiple processes involved in tumor growth and metastasis.Compared with mTORC1,much less is known about mTORC2 in cancer,mainly because of the unavailability of a selective inhibitor.However,existing data suggest that mTORC2 with its two distinct subunits Rictor and mSin1 might play a more important role than assumed so far.It is one of the key effectors of the PI3K/AKT/mTOR pathway and stimulates cell growth,cell survival,metabolism,and cytoskeletal organization.It is not only implicated in tumor progression,metastasis,and the tumor microenvironment but also in resistance to therapy.Rictor,the central subunit of mTORC2,was found to be upregulated in different kinds of cancers and is associated with advanced tumor stages and a bad prognosis.Moreover,AKT,the main downstream regulator of mTORC2/Rictor,is one of the most highly activated proteins in cancer.Primary and secondary liver cancer are major problems for current cancer therapy due to the lack of specific medical treatment,emphasizing the need for further therapeutic options.This review,therefore,summarizes the role of mTORC2/Rictor in cancer,with special focus on primary liver cancer but also on liver metastases.
文摘Inflammatory bowel diseases(IBDs),with blurred etiology,show a rising trend and are of global concern.Of various factors involved in IBD pathogenesis and development,inflammation has been shown to play a major role.Recognition of the molecular and cellular pathways that induce IBD is an emerging subject to develop targeted therapies.Mammalian target of rapamycin(mTOR)is one the most common receptors of many inflammatory pathways,including that of IBD.To this end,we intend to overview the mTOR inhibitors for their possible efficacy in present and future approaches to treatment of IBD.
基金Supported by the National Natural Science Foundation of China(No.81470609No.81500695)
文摘AIM:To elucidate the effect of rapamycin on regulating the production of interleukin(IL)-1β in Aspergillus fumigatus(A.fumigatus)-induced keratitis and to verify whether the expression of IL-1β in A.fumigatus keratitis is associated with the mammalian target of rapamycin(mT OR)/Toll-like receptor 4(TLR4) signaling pathway.METHODS:Fungal keratitis mouse models of susceptible C57 BL/6 mice were established using A.fumigatus.The mice were subsequently treated with rapamycin.The protein levels of p-mT OR,TLR4,and IL-1β in normal and infected corneal tissue were measured by Western blot.The TLR4 and IL-1β m RNA levels were determined by real-time polymerase chain reaction(PCR).RESULTS:In C57 BL/6 mice,rapamycin treatment decreased the clinical scores and production of the pro-inflammatory cytokine,IL-1β.The expression of TLR4,stimulated by A.fumigatus,was reduced as well when the mT OR signaling pathway was suppressed by rapamycin.CONCLUSION:Rapamycin is beneficial for the outcome of fungal keratitis and has an inhibitory effect expression of the inflammatory cytokine IL-1β.The inhibitory effect on IL-1β expression can be associated with the mT OR/TLR4 signaling pathway in A.fumigatus infection in mice.
基金Health and Family Planning Committee Joint Fund Project of Hubei Province,No.WJ2018H0020Fundamental Research Funds for the Central Universities,No.2042016kf0187 and No.2042017kf0068Zhongnan Hospital of Wuhan University Science,Technology and Innovation Seed Fund,No.znpy2016022.
文摘BACKGROUND With continuous advancement of industrial society,environmental pollution has become more and more serious.There has been an increase in infertility caused by environmental factors.Nonylphenol(NP)is a stable degradation product widely used in daily life and production and has been proven to affect male fertility.However,the underlying mechanisms therein are unclear.Thus,it is necessary to study the effect and mechanism of NP on spermatogonial stem cells(SSCs).AIM To investigate the cytotoxic effect of NP on SSCs via the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/AKT/mTOR)pathway.METHODS SSCs were treated with NP at 0,10,20 or 30μmol.MTT assay was performed to evaluate the effect of NP on the proliferation of SSCs.Flow cytometry was conducted to measure SSC apoptosis.The expression of Bad,Bcl-2,cytochrome-c,pro-Caspase 9,SOX-2,OCT-4,Nanog,Nanos3,Stra8,Scp3,GFRα1,CD90,VASA,Nanos2,KIT,PLZF and PI3K/AKT/mTOR-related proteins was observed by western blot,and the mRNA expression of SOX-2,OCT-4 and Nanog was detected by quantitative reverse transcription polymerase chain reaction.RESULTS Compared with untreated cells(0μmol NP),SSCs treated with NP at all concentrations showed a decrease in cell proliferation and expression of Bcl-2,Nanog,OCT-4,SOX-2,Nanos3,Stra8,Scp3,GFRα1,CD90,VASA,Nanos2,KIT,and PLZF(P<0.05),whereas the expression of Bad,cytochrome-c,and pro-Caspase 9 increased significantly(P<0.05).We further examined the PI3K/AKT/mTOR pathway and found that the phosphorylation of PI3K,AKT,mTORC1,and S6K was significantly decreased by NP at all concentrations compared to that in untreated SSCs(P<0.05).NP exerted the greatest effect at 30μmol among all NP concentrations.CONCLUSION NP attenuated the proliferation,differentiation and stemness maintenance of SSCs while promoting apoptosis and oxidative stress.The associated mechanism may be related to the PI3K/AKT/mTOR pathway.
基金Supported by National Natural Science Foundation of China,No.82360329Inner Mongolia Medical University General Project,No.YKD2023MS047Inner Mongolia Health Commission Science and Technology Plan Project,No.202201275.
文摘BACKGROUND Colorectal cancer has a low 5-year survival rate and high mortality.Humanβ-defensin-1(hBD-1)may play an integral function in the innate immune system,contributing to the recognition and destruction of cancer cells.Long non-coding RNAs(lncRNAs)are involved in the process of cell differentiation and growth.AIM To investigate the effect of hBD-1 on the mammalian target of rapamycin(mTOR)pathway and autophagy in human colon cancer SW620 cells.METHODS CCK8 assay was utilized for the detection of cell proliferation and determination of the optimal drug concentration.Colony formation assay was employed to assess the effect of hBD-1 on SW620 cell proliferation.Bioinformatics was used to screen potentially biologically significant lncRNAs related to the mTOR pathway.Additionally,p-mTOR(Ser2448),Beclin1,and LC3II/I expression levels in SW620 cells were assessed through Western blot analysis.RESULTS hBD-1 inhibited the proliferative ability of SW620 cells,as evidenced by the reduction in the colony formation capacity of SW620 cells upon exposure to hBD-1.hBD-1 decreased the expression of p-mTOR(Ser2448)protein and increased the expression of Beclin1 and LC3II/I protein.Furthermore,bioinformatics analysis identified seven lncRNAs(2 upregulated and 5 downregulated)related to the mTOR pathway.The lncRNA TCONS_00014506 was ultimately selected.Following the inhibition of the lncRNA TCONS_00014506,exposure to hBD-1 inhibited p-mTOR(Ser2448)and promoted Beclin1 and LC3II/I protein expression.CONCLUSION hBD-1 inhibits the mTOR pathway and promotes autophagy by upregulating the expression of the lncRNA TCONS_00014506 in SW620 cells.
文摘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.
基金financially supported by the National Key R&D Program(2018YFD0500405)the Science and technology projects of Changsha City(kq1801059)+2 种基金the STS regional key projects of Chinese Academy of Sciences(KFJ-STS-QYZD-052)the Youth Innovation Promotion Association CAS(2016326)the Earmarked Fund for China Agriculture Research System(CARS-35)
文摘Sodium-coupled neutral amino acid transporter 2(SNAT2),also known as solute carrier family 38 member 2(SLC38 A2),is expressed in the skeletal muscle.Our research previously indicated that SNAT2 m RNA expression level in the skeletal muscle was modulated by genotype and dietary protein.The aim of this study was to investigate the key role of the amino acid transporter SNAT2 in muscle cell growth,differentiation,and related signaling pathways via SNAT2 suppression using the inhibitor a-methylaminoisobutyric acid(Me AIB).The results showed that SNAT2 suppression down-regulated both the m RNA and protein expression levels of SNAT2 in C2 C12 cells,inhibited cell viability and differentiation of the cell,and regulated the cell distribution in G0/G1 and S phases(P<0.05).Meanwhile,most of the intercellular amino acid content of the cells after Me AIB co-culturing was significantly lower(P<0.05).Furthermore,the m RNA expression levels of system L amino acid transporter 1(LAT1),silent information regulator 1,and peroxisome proliferator-activated receptor-gamma co-activator 1 alpha,as well as the protein expression levels of amino acid transporters LAT1 and vacuolar protein sorting 34,were all down-regulated.The phosphorylated protein expression levels of mammalian target of rapamycin(m TOR),regulatory-associated protein of m TOR,4 E binding protein 1,and ribosomal protein S6 kinase 1 after Me AIB treatment were also significantly down-regulated(P<0.05),which could contribute to the importance of SNAT2 in amino acid transportation and skeletal muscle cell sensing.In conclusion,SNAT2 suppression inhibited C2 C12 cell growth and differentiation,as well as the availability of free amino acids.Although the m TOR complex 1 signaling pathway was found to be involved,its response to different nutrients requires further study.
基金supported by the National Natural Science Foundation of Hubei Province(No.2018CFC801).
文摘Objective This study aimed to investigate the effects of the peroxisome proliferator-activated receptorδ(PPARδ)agonist GW501516 on the proliferation of pulmonary artery smooth muscle cells(PASMCs)induced by hypoxia,in order to search for new drugs for the treatment and prevention of pulmonary vascular remodeling.Methods PASMCs were incubated with different concentrations of GW501516(10,30,100 nmol/L)under the hypoxic condition.The proliferation was determined by a CCK-8 assay.The cell cycle progression was analyzed by flow cytometry.The expression of PPARδ,S phase kinase-associated protein 2(Skp2),and cell cycle-dependent kinase inhibitor p27 was detected by Western blotting.Then PASMCs were treated with 100 nmol/L GW501516,100 nmol/L mammalian target of rapamycin(mTOR)inhibitor rapamycin and/or 2µmol/L mTOR activator MHY1485 to explore the molecular mechanisms by which GW501516 reduces the proliferation of PASMCs.Results The presented data demonstrated that hypoxia reduced the expression of PPARδin an oxygen concentration-and time-dependent manner,and GW501516 decreased the proliferation of PASMCs induced by hypoxia by blocking the progression through the G0/G1 to S phase of the cell cycle.In accordance with these findings,GW501516 downregulated Skp2 and upregulated p27 in hypoxia-exposed PASMCs.Further experiments showed that rapamycin had similar effects as GW501516 in inhibiting cell proliferation,arresting the cell cycle,regulating the expression of Skp2 and p27,and inactivating mTOR in hypoxia-exposed PASMCs.Moreover,MHY1485 reversed all the beneficial effects of GW501516 on hypoxia-stimulated PASMCs.Conclusion GW501516 inhibited the proliferation of PASMCs induced by hypoxia through blocking the mTOR/Skp2/p27 signaling pathway.
基金supported by grants from the Natural Science Foundation of China(91949205,31730035,81721005)the Science and Technology Committee of China(2016YFC1305800)+1 种基金the Special Project of Technological Innovation of Hubei Province(2018ACA142)Guangdong Provincial Key S&T Program(2018B030336001)。
文摘Background:Autophagy dysfunction plays a crucial role in tau accumulation and neurodegeneration in Alzheimer’s disease(AD).This study aimed to investigate whether and how the accumulating tau may in turn affect autophagy.Methods:The primary hippocampal neurons,N2a and HEK293T cells with tau overexpression were respectively starved and treated with vinblastine to study the effects of tau on the initiating steps of autophagy,which was analysed by Student’s two-tailed t-test.The rapamycin and concanamycin A were employed to inhibit the mammalian target of rapamycin kinase complex 1(mTORC1)activity and the vacuolar H+-ATPase(v-ATPase)activity,respectively,which were analysed by One-way ANOVA with post hoc tests.The Western blotting,co-immunoprecipitation and immunofuorescence staining were conducted to gain insight into the mechanisms underlying the tau effects of mTORC1 signaling alterations,as analysed by Student’s two-tailed t-test or One-way ANOVA with post hoc tests.The autophagosome formation was detected by immunofuorescence staining and transmission electron microscopy.The amino acids(AA)levels were detected by high performance liquid chromatography(HPLC).Results:We observed that overexpressing human full-length wild-type tau to mimic AD-like tau accumulation induced autophagy deficits.Further studies revealed that the increased tau could bind to the prion-related domain of T cell intracellular antigen 1(PRD-TIA1)and this association significantly increased the intercellular level of amino acids(Leucine,P=0.0038;Glutamic acid,P=0.0348;Alanine,P=0.0037;Glycine,P=0.0104),with concordant upregulation of mTORC1 activity[phosphorylated eukaryotic translation initiation factor 4E-binding protein 1(p-4EBP1),P<0.0001;phosphorylated 70 kD ribosomal protein S6 kinase 1(p-p70S6K1),P=0.0001,phosphorylated unc-51-like autophagyactivating kinase 1(p-ULK1),P=0.0015]and inhibition of autophagosome formation[microtubuleassociated protein light chain 3 II(LC3 II),P=0.0073;LC3 puncta,P<0.0001].As expected,this tau-induced deficit of autophagosome formation in turn aggravated tau accumulation.Importantly,we also found that blocking TIA1 and tau interaction by overexpressing PRD-TIA1,downregulating the endogenous TIA1 expression by shRNA,or downregulating tau protein level by a small proteolysis targeting chimera(PROTAC)could remarkably attenuate tau-induced autophagy impairment.Conclusions:Our findings reveal that AD-like tau accumulation inhibits autophagosome formation and induces autophagy deficits by activating the TIA1/amino acid/mTORC1 pathway,and thus this work reveals new insight into tau-associated neurodegeneration and provides evidence supporting the use of new therapeutic targets for AD treat-ment and that of related tauopathies.
基金Supported by Peking University International Hospital Foundation for Scientific Research,No.YN2022QN11。
文摘BACKGROUND Alzheimer’s disease(AD)is the most common neurodegenerative disorder,and there are currently no effective drugs to delay progression of the disease.Ferroptosis may play a vital part in AD,and is therefore receiving increasing attention by researchers.AIM To investigate the effects of dexmedetomidine(Dex)on ferroptosis in AD mouse hippocampus.METHODS Hippocampal neurons(HNs)HT22 were induced by amyloidβ-protein(Aβ)and both in vitro and in vivo AD mouse models were prepared via injections.The cellcounting kit-8 assay and immunofluorescence technique were adopted to determine cell proliferation activity and intracellular Fe2+levels,and the TBA method and microplate method were employed for malondialdehyde and glutathione measurements,respectively.Hippocampal tissue damage was determined using hematoxylin and eosin and Nissl staining.Mouse learning and memory ability in each group was assessed by the Morris water maze test,and the expression levels of mammalian target of rapamycin(mTOR)signal molecules and ferroptosis-related proteins transferrin receptor 1(TFR1),SLC7A11 and glutathione peroxidase 4 were examined by western blotting.RESULTS Dex enhanced lipid peroxidation and iron influx in mouse HNs in both in vitro and in vivo experiments,while inhibition of the mTOR axis blocked this process.These findings demonstrate that Dex can inhibit ferroptosis-induced damage in mouse HNs by activating mTOR-TFR1 signaling to regulate ferroptosis-associated proteins,thus alleviating cognitive dysfunction in AD mice.CONCLUSION Dex can activate the mTOR-TFR1 axis to inhibit ferroptosis in mouse HNs,thereby improving the learning and memory ability of mice.
基金supported by the National Natural Science Foundation of China,No.81403456,81473788a grant from the Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion,No.HBPCIC-2016-003
文摘Defects in autophagy-mediated clearance of α-synuclein may be one of the key factors leading to progressive loss of dopaminergic neurons in the substantia nigra. Moxibustion therapy for Parkinson's disease has been shown to have a positive effect, but the underlying mechanism remains unknown. Based on this, we explored whether moxibustion could protect dopaminergic neurons by promoting autophagy mediated by mammalian target of rapamycin(m TOR), with subsequent elimination of α-syn. A Parkinson's disease model was induced in rats by subcutaneous injection of rotenone at the back of their necks, and they received moxibustion at Zusanli(ST36), Guanyuan(CV4) and Fengfu(GV16), for 10 minutes at every point, once per day, for 14 consecutive days. Model rats without any treatment were used as a sham control. Compared with the Parkinson's disease group, the moxibustion group showed significantly greater tyrosine hydroxylase immunoreactivity and expression of light chain 3-Ⅱ protein in the substantia nigra, and their behavioral score, α-synuclein immunoreactivity, the expression of phosphorylated m TOR and phosphorylated ribosomal protein S6 kinase(p-p70S6K) in the substantia nigra were significantly lower. These results suggest that moxibustion can promote the autophagic clearance of α-syn and improve behavioral performance in Parkinson's disease model rats. The protective mechanism may be associated with suppression of the m TOR/p70S6K pathway.
文摘AIM: To evaluate the expression of serum fibrosis markers in liver transplantation(LT) recipients on everolimus monotherapy compared to patients on an anti-calcineurin regimen.METHODS: This cross-sectional case-control study included LT patients on everolimus monotherapy(cases)(E)(n = 30) and matched controls on an anticalcineurin regimen(calcineurin inhibitors, CNI), paired by etiology of liver disease and time since LT(n = 30). Clinical characteristics, blood tests and elastography were collected. Serum levels of transforming growth factor-β(TGF-β), angiopoietin-1, tumor necrosis factor(TNF), platelet derived growth factor, amino-terminal propeptide of type Ⅲ procollagen(PⅢNP), hyaluronicacid(HA), VCM-1(ng/m L), interleukin(IL)-10, interferoninducible protein 10(IP-10), vascular endothelial growth factor and hepatocyte growth factor(HGF)(pg/m L) were determined by enzyme-linked immunosorbent assay. Expression of these markers between E and CNI was compared. Stratified analysis was done according to factors that may influence liver fibrosis. Variables are described with medians(interquartillic range) or percentages.RESULTS: A total of 60 patients [age: 59(49-64), hepatitis C virus(HCV): n = 21(35%), time from LT: 73 mo(16-105)] were included. Patients had been on everolimus for a median of 15 mo. No differences in inflammatory activity, APRI test or liver elastography were found between the groups. No significant differences were observed between the groups in serum levels of PⅢ NP, metalloproteinase type = 1, angiopoietin, HGF, IP-10, TNF-α, IL-10 and vascular cell adhesion molecule. Patients on E had a lower expression of TGF-β [E: 12.7(3.7-133.6), CNI: 152.5(14.4-333.2), P = 0.009] and HA [E: 702.89(329.4-838.2), CNI: 1513.6(691.9-1951.4), P = 0.001] than those on CNI. This difference was maintained in the stratified analysis when recipient age is more than 50 years(TFG-β1: P = 0.06; HA: P = 0.005), in patients without active neoplasia(TFG-β1, P = 0.009; HA: P = 0.01), according to time since LT(> than 5 years, TFG-β1: P = 0.001; HA: P = 0.002), related to previous history of biliary complications(HA: P = 0.01) and HCV recurrence(HA: P = 0.004). Liver transplant recipients with everolimus monotherapy had less serum expression of TGF-β y HA than matched patients with anti-calcineurins. This difference remains when classifying patients according to donor age and time since LT. Due to the small sample size, when examining patients with a prior history of biliary complications or recurrent HCV, the difference was nonsignificant but trends towards the lower expression of TFG-β1 in the everolimus group. Mammalian target of rapamycin(m TOR) plays a role in the transformation of quiescent hepatocellular stellate cell to their activeprofibrotic state, and experimental models have demonstrated the potential activity of m TOR inhibition in attenuating fibrogenesis.CONCLUSION: This study supports a possible role of everolimus in liver fibrosis modulation after LT in a clinical setting and suggests that tailoring immunosuppression could avoid fibrosis progression in the allograft.
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.
文摘The prevalence of type 2 diabetes(T2D)continues to rise despite the amount of research dedicated to finding the culprits of this debilitating disease.Skeletal muscle is arguably the most important contributor to glucose disposal making it a clear target in insulin resistance and T2D research.Within skeletal muscle there is a clear link to metabolic dysregulation during the progression of T2D but the determination of culprits vs consequences of the disease has been elusive.Emerging evidence in skeletal muscle implicates influential cross talk between a key anabolic regulatory protein,the mammalian target of rapamycin(mTOR)and its associated complexes(mTORC1 and mTORC2),and the well-described canonical signaling for insulin-stimulated glucose uptake.This new understanding of cellular signaling crosstalk has blurred the lines of what is a culprit and what is a consequence with regard to insulin resistance.Here,we briefly review the most recent understanding of insulin signaling in skeletal muscle,and how anabolic responses favoring anabolism directly impact cellular glucose disposal.This review highlights key cross-over interactions between protein and glucose regulatory pathways and the implications this may have for the design of new therapeutic targets for the control of glucoregulatory function in skeletal muscle.
文摘Alzheimer’s disease(AD)is the most common reason for progressive dementia in the elderly.It has been shown that disorders of the mammalian/mechanistic target of rapamycin(mTOR)signaling pathways are related to the AD.On the other hand,diabetes mellitus(DM)is a risk factor for the cognitive dysfunction.The pathogenesis of the neuronal impairment caused by diabetic hyperglycemia is intricate,which contains neuro-inflammation and/or neurodegeneration and dementia.Glucagon-like peptide-1(GLP1)is interesting as a possible link between metabolism and brain impairment.Modulation of GLP1 activity can influence amyloid-beta peptide aggregation via the phosphoinositide-3 kinase/AKT/mTOR signaling pathway in AD.The GLP1 receptor agonists have been shown to have favorable actions on the brain such as the improvement of neurological deficit.They might also exert a beneficial effect with refining learning and memory on the cognitive impairment induced by diabetes.Recent experimental and clinical evidence indicates that dipeptidyl-peptidase-4(DPP4)inhibitors,being currently used for DM therapy,may also be effective for AD treatment.The DPP-4 inhibitors have demonstrated neuroprotection and cognitive improvements in animal models.Although further studies for mTOR,GLP1,and DPP4 signaling pathways in humans would be intensively required,they seem to be a promising approach for innovative AD-treatments.We would like to review the characteristics of AD pathogenesis,the key roles of mTOR in AD and the preventive and/or therapeutic suggestions of directing the mTOR signaling pathway.
基金supported by the National Natural Science Foundation of China(No.82001651 and No.81660268).
文摘Objective Intrauterine growth restriction followed by postnatal catch-up growth(CG-IUGR)increases the risk of insulin resistance-related diseases.Low-density lipoprotein receptor-related protein 6(LRP6)plays a substantial role in glucose metabolism.However,whether LRP6 is involved in the insulin resistance of CG-IUGR is unclear.This study aimed to explore the role of LRP6 in insulin signaling in response to CG-IUGR.Methods The CG-IUGR rat model was established via a maternal gestational nutritional restriction followed by postnatal litter size reduction.The mRNA and protein expression of the components in the insulin pathway,LRP6/β-catenin and mammalian target of rapamycin(mTOR)/S6 kinase(S6K)signaling,was determined.Liver tissues were immunostained for the expression of LRP6 andβ-catenin.LRP6 was overexpressed or silenced in primary hepatocytes to explore its role in insulin signaling.Results Compared with the control rats,CG-IUGR rats showed higher homeostasis model assessment for insulin resistance(HOMA-IR)index and fasting insulin level,decreased insulin signaling,reduced mTOR/S6K/insulin receptor substrate-1(IRS-1)serine307 activity,and decreased LRP6/β-catenin in the liver tissue.The knockdown of LRP6 in hepatocytes from appropriate-for-gestational-age(AGA)rats led to reductions in insulin receptor(IR)signaling and mTOR/S6K/IRS-1 serine307 activity.In contrast,LRP6 overexpression in hepatocytes of CG-IUGR rats resulted in elevated IR signaling and mTOR/S6K/IRS-1 serine307 activity.Conclusion LRP6 regulated the insulin signaling in the CG-IUGR rats via two distinct pathways,IR and mTOR-S6K signaling.LRP6 may be a potential therapeutic target for insulin resistance in CG-IUGR individuals.
文摘BACKGROUND Mesenchymal stem cells(MSCs)are a type of stem cells that possess relevant regenerative abilities and can be used to treat many chronic diseases.Diabetes mellitus(DM)is a frequently diagnosed chronic disease characterized by hyperglycemia which initiates many multisystem complications in the long-run.DM patients can benefit from MSCs transplantation to curb down the pathological consequences associated with hyperglycemia persistence and restore the function of damaged tissues.MSCs therapeutic outcomes are found to last for short period of time and ultimately these regenerative cells are eradicated and died in DM disease model.AIM To investigate the impact of high glucose or hyperglycemia on the cellular and molecular characteristics of MSCs.METHODS Human adipose tissue-derived MSCs(hAD-MSCs)were seeded in low(5.6 mmol/L of glucose)and high glucose(25 mmol/L of glucose)for 7 d.Cytotoxicity,viability,mitochondrial dynamics,and apoptosis were deplored using specific kits.Western blotting was performed to measure the protein expression of phosphatidylinositol 3-kinase(PI3K),TSC1,and mammalian target of rapamycin(mTOR)in these cells.RESULTS hAD-MSCs cultured in high glucose for 7 d demonstrated marked decrease in their viability,as shown by a significant increase in lactate dehydrogenase(P<0.01)and a significant decrease in Trypan blue(P<0.05)in these cells compared to low glucose control.Mitochondrial membrane potential,indicated by tetramethylrhodamine ethyl ester(TMRE)fluorescence intensity,and nicotinamide adenine dinucleotide(NAD+)/NADH ratio were significantly dropped(P<0.05 for TMRE and P<0.01 for NAD+/NADH)in high glucose exposed hAD-MSCs,indicating disturbed mitochondrial function.PI3K protein expression significantly decreased in high glucose culture MSCs(P<0.05 compared to low glucose)and it was coupled with significant upregulation in TSC1(P<0.05)and downregulation in mTOR protein expression(P<0.05).Mitochondrial complexes I,IV,and V were downregulated profoundly in high glucose(P<0.05 compared to low glucose).Apoptosis was induced as a result of mitochondrial impairment and explained the poor survival of MSCs in high glucose.CONCLUSION High glucose impaired the mitochondrial dynamics and regulatory proteins in hAD-MSCs ensuing their poor survival and high apoptosis rate in hyperglycemic microenvironment.
文摘Although multiple advances have been made in systemic therapy for renal cell carcinoma(RCC),metastatic RCC remains incurable.In the current review,we focus on the underlying biology of RCC and plausible mechanisms of metastasis.We further outline evolving strategies to combat metastasis through adjuvant therapy.Finally,we discuss clinical patterns of metastasis in RCC and how distinct systemic therapy approaches may be considered based on the anatomic location of metastasis.
基金the National Natural Science Foundation of China(No.81700265 to Cong FU and No.81702092 to Yu-han CAO).
文摘Objective Ticagrelor is a widely used anti-platelet drug.However,the mechanisms by which ticagrelor protects against sepsis-induced acute kidney injury(AKI)have not been clearly demonstrated.We designed this study to explore the protective effect of ticagrelor on sepsis-induced AKI and to explore the underlying mechanisms.Methods C57BL6J mice received oral ticagrelor(20 mg/kg and 50 mg/kg)for 7 days,and then caecal ligation and puncture(CLP)were performed.An adenosine receptor antagonist,CGS15943,was administered(10 mg/kg,intraperitoneal injection)to block the adenosine pathway 2 h before CLP.After 24 h,serum creatinine levels were measured.Periodic acid-Schiff(PAS)staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL)staining were employed to analyze pathological changes and cell apoptosis.Serum concentrations of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),and mRNA expression of tissue TNF-αand IL-1βwere detected.Western blotting analysis was used to determine AKT and mammalian target of rapamycin(mTOR)protein expression in the kidney.Results PAS staining showed less swelling of renal tubules,and TUNEL staining revealed less cell apoptosis in the ticagrelor group than in the CLP group.Serum creatinine levels were significantly lower in the ticagrelor group than in the CLP group.Moreover,significantly lower serum and kidney levels of TNF-αand IL-1βwere observed in the ticagrelor group.CGS15943 blocked the effects of ticagrelor.Western blotting analysis showed increased phosphorylation of AKT and mTOR in the kidneys of the 50 mg/kg ticagrelor group.The adenosine receptor antagonist inhibited the activation of AKT and mTOR.Conclusion This study demonstrates that the protective effect of ticagrelor on sepsis-induced AKI depends on adenosine receptor activation and the subsequent increase of AKT and mTOR phosphorylation.
