首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 437 毫秒
1.
AIM: To investigate the effect of irbesartan on the fatty liver of db/db mice and whether autophagy is involved in the process. METHODS: Male db/db mice (n=24) were randomly divided into model group and irbesartan group, and 12 db/m mice with similar age and weight were selected as normal control group. After 16 weeks of intervention respectively, the fatty liver-related parameters including body weight, liver index, blood lipid, liver function and pathological changes in the liver were observed. The protein levels of p-PI3K, p-Akt, and p-mTOR, as well as Atg-7, beclin-1 and LC3B in the liver tissues were detected by Western blot, and the autophagosomes in the liver were observed under electron microscope. RESULTS: Compared with the model group, the body weight, liver index, blood lipids, alanine and aspartate aminotransferase were decreased in irbesartan group (P<0.05). Moreover, the pathological changes in the liver were significantly ameliorated in irbesartan group than that of model group. Importantly, the protein levels of p-PI3K, p-Akt and p-mTOR were decreased with irbesartan administration, while the expression of Atg-7, beclin-1 and LC3B-Ⅱ was increased(P<0.05), which resulted in a distinct increase in autophagosomes. CONCLUSION: Irbesartan alleviates hepatic steatosis in db/db mice by inhibiting the PI3K/Akt/mTOR signaling pathway and upregulating the protein expression of Atg-7, beclin-1 and LC3B-Ⅱ, thereby inducing autophagy in hepatocytes.  相似文献   

2.
ATM:To observe the expression change of PTEN and autophagy in the renal tissues of diabetic rats, and to explore the regulatory mechanism of PTEN/AKT/mTOR pathway to autophagy in diabetic nephropathy. METHODS: The Sprague-Dawley rats were randomly divided into normal control group and diabetic group (8 in each group). The diabetic rat model was established by injection of streptozotocin. The biochemical and kidney indexes were measured after the model of diabetic nephropathy was successfully established. The expression location of PTEN in the renal tubular epithelial cells was observed by the method of immunohistochemistry. The protein levels of autophagy-related protein LC3, PTEN and PTEN/AKT/mTOR signalling molecules were determined by Western blotting. The mRNA expression of PTEN was detected by real-time PCR. RESULTS: The blood glucose, 24 h urine protein and kidney index in diabetic group were all obviously higher than those in control group. Compared with control group, the protein levels of LC3I and LC3II in diabetic group were obviously decreased. PTEN was mainly located in the renal tubular epithelial cells. Compared with control group, the protein expression of PTEN was significantly down-regulated in diabetic group. Furthermore, the activity of PTEN/AKT/mTOR pathway increased in diabetic nephropathy rats. CONCLUSION: The level of autophagy in renal tissues of diabetic rats is decreased, whereas the activity of PTEN/AKT/mTOR pathway is increased. The level of autophagy may be mediated by PTEN/AKT/mTOR pathway.  相似文献   

3.
AIM: To explore the protective effect of fasudil hydrochloride against cisplatin(CP)-induced renal tubular epithelial cell apoptosis via Akt activation and PTEN inhibition. METHODS: Healthy male Sprague-Dawley (SD) rats were randomly divided into control group, CP group and CP+ fasudil group. All animals were sacrificed 96 h after injection of 0.9% saline or CP. Blood samples and kidney tissues were collected to evaluate levels of blood urea nitrogen (BUN), serum creatinine (sCr) and morphological alteration of the kidneys, respectively. The apoptosis of renal tubular epithelium cells was detected by TUNEL. Protein levels of Rho-associated protein kinase 1 (ROCK1), PTEN and Akt were measured by Western blotting and immunohistochemistry. The protein level of p-Akt was analyzed by Western blotting. RESULTS: Compared with control group, the sCr and BUN levels, the expression of ROCK1 and PTEN and TUNEL-positive cells were increased, while the level of p-Akt was decreased in CP group and CP+fasudil group. The histological structure of the kidneys observed by PAS staining was developed marked structural damage in CP group(P<0.05). Compared with CP group, sCr level, the expression of ROCK1 and PTEN and TUNEL-positive cells were decreased, while the level of p-Akt was increased in CP+fasudil group (P<0.05). Very little structural damage was detected in fasudil-treated groups. CONCLUSION: Fasudil hydrochloride has a protective effect on CP-induced renal tubular epithelial cell apoptosis via Akt activation and PTEN inhibition 1.  相似文献   

4.
YANG Yi  TANG Xiao-li  LIU Yue  FANG Fang 《园艺学报》2019,35(11):2028-2034
AIM: To explore whether the damage of neurons induced by amyloid β-protein (Aβ) is related to the regulation of autophagy and its mechanism based on Akt/mTOR pathway. METHODS: SH-SY5Y cells were incubated with Aβ25-35 (5 μmol/L, 10 μmol/L, 15 μmol/L, 20 μmol/L and 25 μmol/L) for 24 h, and the cell viability was measured by MTT assay. The protein levels of LC3-I, LC3-II, Akt, p-Akt, mTOR and p-mTOR in the SH-SY5Y cells were determined by Western blot. After the SH-5Y5Y cells were incubated with autophagy inducer rapamycin (Rapa) or autophagy inhibitor 3-methyladenine (3-MA) combined with Aβ25-35 for 24 h, the cell viability and related protein expression were detected by the same methods above mentioned. RESULTS: Each concentration of Aβ25-35 damaged SH-SY5Y cells and decreased the viability of SH-SY5Y cells. Aβ25-35 increased the expression of autophagy marker protein LC3-II, increased the level of LC3-II/LC3-I, and down-regulated the phosphorylation level of Akt and mTOR proteins (P<0.05). When combined with autophagy inducer Rapa, the cell viability was not significantly affected, the expression of LC3-II protein was increased, LC3-II/LC3-I was increased significantly, and p-mTOR/mTOR level was decreased (P<0.05). When combined with autophagy inhibitor 3-MA, the protein expression of LC3-II and the level of LC3-II/LC3-I showed a downward trend, while the level of p-Akt/Akt was decreased (P<0.05). CONCLUSION: Aβ25-35 may induce SH-SY5Y cell autophagy and injury by down-regulating phosphorylation levels of Akt and mTOR proteins.  相似文献   

5.
AIM: To explore the effect of dual PI3K/Akt/mTOR inhibitor NVP-BEZ235 on autophagy of polycystic kidney (PCK) rat cholangiocytes. METHODS: The protein levels of p-mTOR and p-Akt in the bile duct epithelial cells were examined by immunohistochemistry. The effect of NVP-BEZ235 on the viability of cholangiocytes was detected by WST-1 assay. The levels of PI3K/Akt/mTOR signaling pathway and autophagy-related proteins with NVP-BEZ235 treatment were determined by Western blot. The effects of LC3 and Beclin 1 silencing, and authophagy-specific inhibitor 3-methyladenine (3-MA) on the cell viability were analyzed by WST-1 assay. RESULTS: The protein levels of p-Akt and p-mTOR were highly increased in the bile duct epithelium of the PCK rats. NVP-BEZ235 significantly inhibited the viability of the cholangiocytes in a dose- and time-dependent manner (P<0.05). NVP-BEZ235 significantly reduced the levels of PI3K/Akt/mTOR signaling pathway-related proteins in the PCK rat cholangiocytes. NVP-BEZ235 upregulated the autophagy-specific proteins LC3 II and Beclin 1. The inhibitory effect of NVP-BEZ235 on the cell viability was weakened by treatment with 3-MA and knockdown of LC3 and Beclin 1 (P<0.01).CONCLUSION: The PI3K/Akt/mTOR inhibitor NVP-BEZ235 suppresses the viability of PCK rat cholangiocytes, and the mechanism is closely related with autophagy.  相似文献   

6.
AIM:To observe the effects of shikonin on the apoptosis and autophagy of human cervical cancer HeLa cells, and to explore the possible role of PI3K/Akt/mTOR signaling pathway in these processes. METHODS:The HeLa cells were treated with shikonin, and the cell viability was detected by CCK-8 assay. The apoptosis was detected by Annexin V/PI double staining. The autophagosome was observed by transfection with GFP-LC3 into the HeLa cells. After the treatment with shikonin combined with autophagy inhibitor 3-methyladenine (3-MA) or apoptosis inhibitor Z-DEVD-FMK, the protein levels of autophagy-and apoptosis-related molecules microtuble-associated protein 1 light chain 3 (LC3) and cleaved caspase-3 in the HeLa cells were determined by Western blot. The protein levels of phosphorylated PI3K (p-PI3K), phosphorylated Akt (p-Akt) and phosphorylated mTOR (p-mTOR) were also determined by Western blot. RESULTS:Shikonin significantly inhibited the viability of HeLa cells (P<0.05). Compared with control group, shikonin significantly induced apoptosis of HeLa cells (P<0.05). The results of GFP-LC3 plasmid transfection analysis showed that green dot-like congregate autophagosomes appeared in the cytoplasm of the HeLa cells after shikonin treatment, while the autophagosomes were rarely observed in control group. Compared with shikonin group, LC3-Ⅱ/LC3-I was significantly decreased and cleaved caspase-3 was significantly increased in shikonin+3-MA group (P<0.05). Compared with shikonin group, LC3-Ⅱ/LC3-I was significantly increased and cleaved caspase-3 was significantly decreased in shikonin+Z-DEVD-FMK group (P<0.05). Compared with control group, shikonin significantly decreased the protein levels of p-PI3K, p-Akt and p-mTOR (P<0.05). CONCLUSION:The apoptosis and autophagy of the HeLa cells are induced by shikonin, these two processes are complementary. The mechanism may be related to inhibition of PI3K/Akt/mTOR signaling pathway.  相似文献   

7.
AIM: To explore whether NOD8 inhibits autophagy in human pancreatic cancer cells and its underlying mechanisms, and to investigate the effect of apoptosis on the autophagy regulated by NOD8. METHODS: The empty plasmid pEGFP-C2 and recombinant plasmid pEGFP-NOD8 were transfected into the Panc-1 cells using JetPRIME reagent.The untransfected cells served as control group. The protein levels of NOD8, autophagy-related proteins beclin-1 and LC3-II, and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway-related proteins Akt, p-Akt, mTOR and p-mTOR were determined by Western blot 48 h after transfection. Meanwhile, the number of LC3 spots was quantified by immunofluorescence staining. Furthermore, after a broad caspase inhibitor Z-VAD-FMK was applied to NOD8-over-expressing cells, the protein expression levels of beclin-1 and LC3-II were detected by Western blot and the number of LC3 spots was observed by immunofluorescence staining. RESULTS: The protein level of NOD8 in pEGFP-NOD8 group was significantly higher than that in control group and pEGFP-C2 group (P<0.01). The protein expression of beclin-1 and LC3-II, and the number of LC3 spots in pEGFP-NOD8 group were significantly decreased as compared with control group and pEGFP-C2 group. Moreover, the protein levels of p-AKT and p-mTOR in pEGFP-NOD8 group were higher than those in control group and pEGFP-C2 group, while no significant difference of mTOR and AKT protein expression was found among these 3 groups. Furthermore, the protein levels of beclin-1 and LC3-II, and the number of LC3 spots in pEGFP-NOD8+Z-VAD-FMK group were significantly increased compared with pEGFP-NOD8 group. CONCLUSION: NOD8 inhibits autophagy in the Panc-1 cells and its mechanism may be related to the activation of PI3K/Akt/mTOR pathways. Apoptosis enhances the inhibitory effect of NOD8 on autophagy.  相似文献   

8.
AIM：To investigate the autophagy induced by sepsis and acute kidney injury, and the regulation of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway in this process. METHODS：The rats were subjected to cecal ligation and puncture (CLP) or sham operation. Histopathologic changes of the renal tissues were examined by HE staining. Blood urea nitrogen (BUN) and serum creatinine (SCr) were measured by chemical colorimetry. The protein expression of microtubule-associated protein light chain 3 I/II (LC3 I/II), beclin-1 and p-Akt at different time points after CLP was detected by Western blotting. In vitro, human proximal tubular epithelial cell line HK-2 were treated with LPS to induce autophagy. The protein expression of LC3 I/II and p-Akt in the HK-2 cells after LPS treatment at different time points and different concentrations was detected by Western blotting. These molecules in HK-2 cells and apoptosis of HK-2 cells treated with LPS plus PI3K inhibitor or Akt inhibitor were also detected. RESULTS：Compared with sham group, the severe changes of renal histopathological injuries in CLP groups were observed, the levels of BUN and SCr in CLP groups were significantly increased. LC3 I/II, beclin-1 and phosphorylation of Akt gradually increased after CLP. After treatment with LPS, the expression of p-Akt (308) in the HK-2 cells gradually increased in a dose- and time-dependent fashion. The expression of beclin-1 and p-Akt (472) reached a peak at 8 h or 10 mg/L LPS treatment. Treatment with PI3K or Akt inhibitor down-regulated the expression of LC3 and promoted the apoptosis of HK-2 cells. CONCLUSION：Autophagy in the kidney is induced by sepsis and acute kidney injury. PI3/Akt signaling pathway may be involved in this process.  相似文献   

9.
DING Chang  YIN Ping  ZHAO Qi  SU Li 《园艺学报》2020,36(7):1230-1236
AIM To investigate the effect of nuciferine （NUF) on the formation of foam cells and its possible molecular mechanism. METHODS Human monocyte-macrophage cell line THP-1 was induced by oxidized low-density lipoprotein (Ox-LDL) to establish foam cell model, and simultaneously treated with NUF at 5, 10 or 20 μmol/L. Oil red O staining was used and total cholesterol content was measured to observe the effect of NUF on foam cell formation. Autophagy flow was detected by immunofluorescence， and autophagosomes were detected by transmission electron microscopy. The protein levels of microtubule-associated protein 1 light chain 3 (LC3), P62, phosphorylated protein kinase B (p-Akt) and phosphorylated mammalian target of rapamycin (p-mTOR) were determined by Western blot. 3-Methyladenine (3-MA), an autophagy inhibitor, was used to inhibit autophagy and to observe whether NUF inhibited foam cell formation by regulating autophagy. RESULTS Compared with control group, the intracellular lipid deposition and total cholesterol content in Ox-LDL group were increased. Compared with Ox-LDL group, the intracellular lipid deposition and total cholesterol content in NUF group were decreased, while autophagy flow and number of autophagosomes were increased. The inhibitory effect of NUF on cell foaming was weakened after 3-MA treatment. Moreover, NUF decreased the protein levels of p-mTOR and p-Akt. CONCLUSION Nuciferine may promote autophagy by inhibiting phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR signaling pathway, thus reducing intracellular lipid deposition and formation of foam cells.  相似文献   

10.
AIM：To investigate whether selective inhibition of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway stabilizes the vulnerable atherosclerotic plaques by promoting macrophage autophagy.METHODS：In in vitro study, casodex (20 μmol/L), rapamycin (10 nmol/L) or mTOR-siRNA (30 nmol/L) was used to treat mouse macrophage cell line RAW 264.7. Inflammation-related cytokines secreted by macrophages were measured by means of ELISA. Ultrastructural changes of the macrophages were examined by transmission electron microscopy. The mRNA and protein expression levels of Akt, mTOR and autophage-related protein Beclin 1 were assayed by real-time fluorescence quantitative RT-PCR and Western blotting. The expression of autophagy-related indicator LC3-II was detected by immunofluorescence and Western blotting. In in vivo study, 24 New Zealand white rabbits underwent balloon-induced abdominal aortic wall injury and were fed with a diet of 1% cholesterol for 8 weeks. The rabbits were randomly divided into control group (n=8), casodex group (1.0 mg·kg-1·d-1, n=8) and rapamycin group (0.5 mg·kg-1·d-1, n=8). Four weeks after drug administration, intravascular ultrasound (IVUS) was carried out to observe the plaque imaging. Ultrastructural changes of the macrophages and the protein expression of Akt, mTOR and LC3-II in the macrophages were also measured.RESULTS：In in vitro study, more typical autophagosomes were detected in casodex-, rapamycin- or mTOR-siRNA-treated cells. The expression level of LC3-II increased, but Beclin 1,p-Akt and p-mTOR significantly decreased in the 3 treatment groups. The concentration of IL-10 decreased while IFN-γ significantly increased in the treatment groups. In in vivo study, IVUS found that external elastic membrane area (EEMA),plaque area(PA) and plaque burden (PB) significantly decreased in casodex and rapamycin treatment groups. Expression of LC3-II increased significantly in the 2 treatment groups. The staining of RAM-11 and p-mTOR in the macrophages was significantly reduced as compared with control group.CONCLUSION：Selective inhibition of PI3K/Akt/mTOR signaling pathway reduces the infiltration of macrophages and stabilizes the vulnerable atherosclerotic plaques by promoting macrophage autophagy.  相似文献   

11.
AIM: To detect the activation of macrophage autophagy caused by lipopolysaccharide (LPS) and the possible related signaling pathways. METHODS: The macrophage cell line RAW264.7 cultured in vitro was divided into 5 groups according to the culture environment, including normal culture group, starvation-activated sautophagy group, LPS group, LPS+PI3K inhibitor (hVps34) group and LPS+mTOR inhibitor (rapamycin) group. Fluorescent expression vector pcDNA3.1-GFP-LC3 constructed in previous work was transfected into the macrophages.The fluorescence microscopy was used to detect the formation of autophagosome. The mRNA expression of autophagy-associated genes Atg5, Atg7, LC3-II and Bnip3 in the macrophages was detected by qRT-PCR. The protein levels of LC3-II, p-Akt and p-mTOR were determined by Western blotting, so as to evaluate the molecular pathways of autophagy in LPS-activated macrophages. RESULTS: The macrophages stably expressing GFP-LC3 were successfully established, which were used to observe the autophagy under fluorescence microscope.Compared with normal culture group, the autophagy in starvation group, LPS+hVps34 group and LPS+rapamycin group was significantly increased. The mRNA expression levels of Atg5, LC3-II and Bnip3 were significantly increased in starvation group, LPS+hVps34 group and LPS+rapamycin group, while in LPS group, those decreased slightly. The protein level of p-Akt in starvation group, LPS group and LPS+rapamycin group was significantly increased, while p-mTOR in starvation group, LPS+hVps34 group and LPS+rapamycin group significantly declined. LC3-II expression level in starvation group, LPS+hVps34 group and LPS+rapamycin group was higher than that in control group and LPS group. CONCLUSION: LPS regulates macrophage autophagy, and its possible pathway is the PI3K/Akt/mTOR pathway, but there are some other effective regulatory pathways.  相似文献   

12.
AIM To investigate the effect of tetrandrine on the autophagy of human ovarian serous cystadenocarcinoma SKOV3 cells, and to explore its molecular mechanism. METHODS The SKOV3 cells were treated with various concentrations of tetrandrine, and the cell viability was measured by MTT assay. The formation of autophagolysosomes was observed by acridine orange staining under fluorescence microscope. The protein levels of LC3, mTOR, p-mTOR, Akt and p-Akt in the SKOV3 cells were determined by Western blot. The viability of the SKOV3 cells treated with tetrandrine alone or combined with autophagy inhibitor 3-methyladenine (3-MA) were measured by MTT assay. RESULTS Tetrandrine significantly inhibited the viability of SKOV3 cells in a dose-dependent manner (P<0.01). The results of acridine orange fluorescence staining showed that the number of intracellular autophagolysosomes with bright red fluorescence in the SKOV3 cells was significantly increased after tetrandrine treatment, while the autophagolysosomes were rarely observed in control group. The protein levels of LC3-II and P62 in the SKOV3 cells were significantly increased after tetrandrine treatment (P<0.01). Furthermore, treatment with tetrandrine resulted in significant down-regulation of phosphorylated form of mTOR and AKT in the SKOV3 cells (P<0.01), while total mTOR and AKT protein levels were not changed. Finally, combination of tetrandrine and 3-MA significantly decreased the cell viability compared with using tetrandrine alone (P<0.01). CONCLUSION The autophagy of human ovarian cancer SKOV3 cells were induced by tetrandrine and the molecular mechanism may be related to inhibition of PI3K/Akt/mTOR signaling pathway．  相似文献   

13.
DU Wen-xia  JI Xia 《园艺学报》2016,32(7):1241-1245
AIM: To investigate the expression of microRNA-193b(miR-193b) in the cervical tissues, and further to explore the effect of silencing miR-193b on diamminedichloroplatinum(DDP)-treated HeLa cell viability. METHODS: The expression levels of miR-193b in different cervical tissues were examined by qPCR. After transfection of miR-193b-inhibitor, the cell migration was determined by Transwell assay, the sensitivity of HeLa cells to DDP was measured by MTT assay, the protein levels of phosphate and tension homology deleted on chromsome ten(PTEN), protein kinase B(Akt), p-Akt and p-glycoprotein(P-gp) were determined by Western blot. RESULTS: The mRNA level of miR-193b was significantly increased in the cervical cancer tissues compared with normal cervical tissues(P<0.05). Knockdown of miR-193b obviously inhibited migration and enhanced sensitivity to DDP of HeLa cells(P<0.05). Additionally, after transfection of miR-193b-inhibitor, the expression of PTEN was increased, whereas the protein levels of p-Akt and P-gp were decreased(P<0.05). CONCLUSION: miR-193b is highly expressed in the cervical cancer tissues. Inhibition of miR-193b augments the sensitivity to DDP of HeLa cells, at least in part, through PTEN-PI3K/Akt signaling pathway.  相似文献   

14.
AIM: To investigate the effect of GSTP1 over-expression on the sensitivity of human hepatoma HepG2 cells to oxaliplatin (OXA). METHODS: Adenovirus carrying GSTP1 (Ad-GSTP1) was used to infect HepG2 cells for establishing the cell line over-expressing GSTP1. The cells were randomly divided into 6 groups:control, vehicle, Ad-GSTP1, OXA, OXA+vehicle and OXA+Ad-GSTP1. The cell survival rates were examined by CCK-8 assay, and the apoptotic rates were analyzed by flow cytometry. The protein levels of GSTP1, Akt, mTOR, p-Akt and p-mTOR were determined by Western blot. RESULTS: OXA decreased the cell survival rate in a dose-dependent manner (P<0.05). The protein expression of GSTP1 increased after transfection with adenovirus. At basal level, up-regulation of GSTP1 significantly decreased the cell survival rate, increased the cell apoptosis, and inhibited the phosphorylation levels of Akt and mTOR (P<0.05). Moreover, GSTP1 over-expression enhanced the effect of OXA on the cell viability, cell apoptosis, and further inhibited the phosphorylation levels of Akt and mTOR (P<0.05).CONCLUSION: Over-expression of GSTP1 augments the enhanced effect of OXA on HepG2 cell apoptosis, which may be related to the inactivation of Akt/mTOR signaling pathway.  相似文献   

15.
AIM To investigate the crosstalk between autophagy and apoptosis caused by receptor-interacting protein 2 (Rip2) and its underling mechanisms in human pancreatic cancer cells. METHODS Plasmids (pEGFP-C2 and pEGFP-Rip2) were transfected into human pancreatic cancer Panc-1 cells by jetPRIME method. The Panc-1 cells transfected with pEGFP-Rip2 were treated with 3-methyladenine (3-MA), an autophagy inhibitor. The apoptotic rate was analyzed by flow cytometry. The levels of apoptosis-associated proteins were measured by Western blot. The activity of caspase-8, -9 and -3 was examined by colorimetric method. Moreover, the Panc-1 cells transfected with pEGFP-Rip2 were treated with Z-VAD-FMK, a broad inhibitor of caspases. Subsequently, the levels of autophagy- and PI3K/Akt/mTOR signaling pathway-related proteins were assessed by Western blot. The autophagosomes were observed under transmission electron microscope. RESULTS (1) The apoptotic rate in pEGFP-Rip2 group markedly increased as compared with control group and pEGFP-C2 group, while the apoptotic rate in pEGFP-Rip2+3-MA group was further elevated compared with pEGFP-Rip2 group (P<0.05). Meanwhile, the protein levels of Fas, Bax and cytoplasmic cytochrome c (Cyt-c) were significantly increased, and the protein expression of Bcl-2 was markedly reduced in pEGFP-Rip2+3-MA group as compared with pEGFP-Rip2 group (P<0.05). The activity of caspase-8, -9 and -3 in pEGFP-Rip2+3-MA group was higher than that in pEGFP-Rip2 group. (2) The protein expression of beclin-1 and LC3-Ⅱ was significantly increased and more accumulated autophagosomes were observed under transmission electron microscope in pEGFP-Rip2+Z-VAD-FMK group as compared with pEGFP-Rip2 group. Furthermore, the protein levels of p-mTOR and p-Akt in pEGFP-Rip2+Z-VAD-FMK group were markedly reduced compared with pEGFP-Rip2 group, while no significant difference of mTOR and Akt protein expression was found between the 2 groups. CONCLUSION Inhibition of autophagy promotes apoptosis induced by Rip2 in the pancreatic cancer cells. Its mechanism may be associated with the further activation of the intrinsic and extrinsic apoptotic pathways. Suppression of apoptosis accelerates autophagy induced by Rip2 in the pancreatic cancer cells, and the mechanism may be related to the further down-regulation of PI3K/Akt/mTOR signaling pathways. There is a mutual antagonistic effect between autophagy and apoptosis caused by Rip2 in pancreatic cancer cells.  相似文献   

16.
AIM: To explore the potential correlation between the expression of phosphatase and tensin homology deleted on chromosome 10(PTEN) and RIF in IgA nephropathy. METHODS: Forty-seven patients diagnosed as primary IgA nephropathy by renal histology were involved. 10 specimens from normal renal tissue of renal carcinoma served as control group. Tubulointerstitial lesion (TIL) was classified by using Katafuchi scale, including no TIL (group I), mild TIL (group II), moderate TIL (group III), severe TIL (group IV). The expressions of PTEN, TGF-β1, α-SMA and ColⅢ in renal tissue were detected by immunohistochemistry. PTEN mRNA was detected by in situ hybridization. RESULTS: Renal tissues from renal biopsy showed abundant expressions of PTEN and PTEN mRNA in endochylema of renal tubular epithelial cells, and negligible expression in glomeruli. With the progress of TIF in IgA nephropathy, the expressions of PTEN and PTEN mRNA decreased gradually (P<0.05). In contrast, the expressions of TGF-β1, α-SMA and ColⅢ increased significantly (P<0.05). The expressions of PTEN and PTEN mRNA in renal tissues were positively with eGFR and urine osmotic pressure (P<0.01), negatively correlated with the expressions of TGF-β1, α-SMA, ColⅢ, urinary protein excretion for 24 h, the rate of sclerosis glomeruli and the scores of vascular lesion (P<0.01). CONCLUSION: These results suggest the loss of PTEN expression in RIF of IgA nephropathy. Moreover, TGF-β signaling induces epithelial to mesenchymal transition and extracellular matrix accumulation possibly through a mechanism dependent on the downregulation of PTEN.  相似文献   

17.
AIM:To explore whether receptor-interacting protein 2 (Rip2) induces autophagy and its under-lying mechanisms in human pancreatic cancer cell line Panc-1. METHODS:The empty plasmid pEGFP-C2 or recombinant plasmid pEGFP-Rip2 was transfected into the Panc-1 cells by jetPRIME reagent. The untreated cells served as control group. The protein levels of Rip2, autophagy-related molecules (beclin-1 and LC3-Ⅱ), and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway-related proteins were determined by Western blot 48 h after transfection. The morphological changes of the autophagosomes were observed by transmission electron microscopy. RESULTS:The protein level of Rip2 was significantly increased in the Panc-1 cells transfected with pEGFP-Rip2 plasmid. The protein expression of beclin-1 and LC3-Ⅱ in pEGFP-Rip2 group was higher than that in control group and pEGFP-C2 group (all P<0.01). An increased number of autophagosomes was observed under transmission electron microscope in pEGFP-Rip2 group as compared with control group and pEGFP-C2 group. Furthermore, the protein levels of p-mTOR and p-AKT in pEGFP-Rip2 group were lower than those in control group and pEGFP-C2 group (all P<0.01), while no significant difference of the total mTOR and AKT protein levels was found among the 3 groups. CONCLUSION:Rip2 induces autophagy in the Panc-1 cells and its mechanism may be related to inhibiting the activation of PI3K/Akt/mTOR pathway.  相似文献   

18.
AIM:To investigate the down-regulation of phosphatase and tensin homolog deleted on chromosome 10(PTEN) gene by adenovirus-mediated short hairpin RNA(shRNA) on proliferation and apoptosis of activated hepatic stellate cells(HSCs) in vitro and the related signaling transduction pathways. METHODS:The activated HSCs were cultured in vitro and transfected with recombinant adenovirus expressing shRNA targeting PTEN. The proliferation of HSCs was measured by MTT assay and the apoptosis was assessed by TUNEL and flow cytometry. Western blotting was used to detect the protein levels of PTEN, Bax, Bcl-2, Akt, p-Akt, ERK1/2 and p-ERK1/2 in HSCs, and real-time fluorescent quantitative PCR was applied to detect the mRNA expression of Akt and ERK1. RESULTS:The recombinant adenovirus expressing shRNA targeting PTEN was successfully transfected into activated HSCs in vitro, and significantly promoted the proliferation of HSCs in a time-dependent manner within a certain extent. The apoptotic rate of HSCs was significantly decreased 72 h after transfection(P<0.05). Meanwhile, reduced expression of Bax and elevated expression of Bcl-2 were induced 72 h after transfection(P<0.05). Furthermore, the expression of p-Akt and p-ERK1/2 were increased significantly(P<0.05), while no significant difference in the expression of Akt and ERK1 at mRNA and protein levels was observed(P>0.05). CONCLUSION:Down-regulation of PTEN by adenovirus-mediated shRNA dramatically promotes the proliferation of activated HSCs, and inhibits the apoptosis through Bcl-2/Bax pathway. In addition, the phosphorylation of Akt and ERK1/2 is increased, indicating that PI3K/Akt and ERK1/2 signal transduction pathways may play an important role in the regulation of proliferation and apoptosis of HSCs.  相似文献   

19.
  相似文献   

20.
AIM: To study the effects of baicalin on CA46 cell xenografts in nude mice. METHODS: The nude mice with CA46 cell xenografts were treated with drugs via intraperitoneal injection daily, and were divided into 5 groups: negative control group, 15 mg/kg baicalin group, 30 mg/kg baicalin group, 60 mg/kg baicalin group and 4 mg/kg etoposide (VP-16) positive control group. After 12-day treatment, the weight of CA46 cell xenografts stripped from some nude mice in the 5 groups was used to evaluate the effect of baicalin on xenograft growth in the nude mice. The apoptosis, necrosis and pathological changes of the xenograft cells were examined under light microscope and transmission electronic microscope respectively. The expression levels of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway-related proteins extracted from xenografts were determined by Western blotting. The other nude mice with CA46 cell xenografts in the 5 groups continued to be treated with the drugs until death in order to evaluate the effect of balcalin on survival time of the nude mice with CA46 cell xenografts. RESULTS: Baicalin remarkably inhibited the growth of CA46 cell xenografts, induced apoptosis and necrosis of xenograft cells, and reduced the protein expression of phospho-Akt (p-Akt), nuclear factor-kappa B (NF-κB), mammalian target of rapamycin (mTOR) and phospho-mTOR (p-mTOR) in the xenografts after 12-day treatment. Furthermore, baicalin prolonged the survival time of the nude mice with CA46 cell xenografts in a dose-dependent manner. CONCLUSION: Baicalin inhibits the growth and induces apoptosis of CA46 cell xenografts in the nude mice, and prolongs the survival time of the nude mice with CA46 cell xenografts through the mechanism of down-regulating PI3K/Akt/NF-κB and PI3K/Akt/ mTOR signaling pathways.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号