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Objective To investigate the effects of abated microRNA-21 (miRNA-21) on phosphatase and tensin homologue on chromosome ten protein (PTEN) and PI3K/Akt/mTOR pathway,as well as their further influence on the autophagy in high glucose (HG,25.0 mmol/L) induced rat glomerular mesangial cells.Methods MiRNA-21 inhibitor and negative control were transfected by liposome 2000 into rat glomerular mesangial cells (HBZY-1).The cells were divided into normal glucose (5.5 mmol/L) group,normal glucose + negative control group,normal glucose +miRNA-21 inhibitor group,HG group,HG+negative control group and HG+miRNA-21 inhibitor group.Cell proliferation and hypertrophy were assayed by MTT and the ratio of total protein to cell number respectively.The miRNA-21 expression was detected using real time PCR.The expressions of PTEN/ Akt/mTOR signaling signatures,autophagy-associated protein (p62 and LC3 Ⅱ) and collagen Ⅰ was detected by Western blotting and real time PCR.Autophagosomes were observed using electron microscopy.Results Compared with those in normal glucose group,in HG group cells had hypertrophy and proliferation,up-regulated miRNA-21 expression,and down-regulated PTEN protein and mRNA expressions (all P ＜ 0.01).Also there were and up-regulated p-Akt,p-mTOR,p62 and collagen Ⅰ expression,and lower LC3 Ⅱ expression and autophagosomes (all P ＜ 0.01).Further,compared with those in HG group,cells hypertrophy and proliferation in HG+miRNA-21 inhibitor group were reduced,expressions of p-Akt,p-mTOR,p62 and collagen Ⅰ were down-regulated,while expressions of PTEN and LC3 Ⅱ and autophagosomes were up-regulated (all P ＜ 0.01).Conclusions MiRNA-21 inhibitor up-regulates PTEN expression,which inhibits the activation of Akt/mTOR signaling pathway,ameliorates cell hypertrophy,proliferation and enhances autophagy to reduce extracellular matrix accumulation.
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Objective@#To investigate the effects of abated microRNA-21 (miRNA-21) on phosphatase and tensin homologue on chromosome ten protein (PTEN) and PI3K/Akt/mTOR pathway, as well as their further influence on the autophagy in high glucose (HG, 25.0 mmol/L) induced rat glomerular mesangial cells.@*Methods@#MiRNA-21 inhibitor and negative control were transfected by liposome 2000 into rat glomerular mesangial cells (HBZY-1). The cells were divided into normal glucose (5.5 mmol/L) group, normal glucose+negative control group, normal glucose+miRNA-21 inhibitor group, HG group, HG+negative control group and HG+miRNA-21 inhibitor group. Cell proliferation and hypertrophy were assayed by MTT and the ratio of total protein to cell number respectively. The miRNA-21 expression was detected using real time PCR. The expressions of PTEN/Akt/mTOR signaling signatures, autophagy-associated protein (p62 and LC3 Ⅱ) and collagen Ⅰ was detected by Western blotting and real time PCR. Autophagosomes were observed using electron microscopy.@*Results@#Compared with those in normal glucose group, in HG group cells had hypertrophy and proliferation, up-regulated miRNA-21 expression, and down-regulated PTEN protein and mRNA expressions (all P<0.01). Also there were and up-regulated p-Akt, p-mTOR, p62 and collagen Ⅰ expression, and lower LC3 Ⅱ expression and autophagosomes (all P<0.01). Further, compared with those in HG group, cells hypertrophy and proliferation in HG+miRNA-21 inhibitor group were reduced, expressions of p-Akt, p-mTOR, p62 and collagen Ⅰ were down-regulated, while expressions of PTEN and LC3 Ⅱ and autophagosomes were up-regulated (all P<0.01).@*Conclusions@#MiRNA-21 inhibitor up-regulates PTEN expression, which inhibits the activation of Akt/mTOR signaling pathway, ameliorates cell hypertrophy, proliferation and enhances autophagy to reduce extracellular matrix accumulation.
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Objective To investigate the expression of Notch signaling molecules, transforming growth factor-β (TGF-β) and fibronectin (FN) in mesangial cell induced by high glucose, and the underlying mechanism of cordyceps sinensis.Methods Rat glomerular mesangial cells were divided into following groups: normal control group (5.5 mmol/L glucose), hypertonic control group (5.5 mmol/L glucose+ 19.5 mmol/L mannitol), high glucose group (25.0 mmol/L glucose), DAPT inhibitor group (25.0 mmol/L glucose + 1 μmol/L DAPT), cordyceps sinensis intervention group (25.0 mmol/L glucose+10 mg/L cordyceps sinensis).Cell proliferation was detected by MTT.The protein and mRNA expression of Notch signaling molecules (Notch1, Jagged1 and Hes1), TGF-β and FN was detected by Western blotting and real time PCR.Results Compared with normal control group, high glucose induced mesangial cell proliferation, as well as the mRNA and protein expression of Notch1, Jagged1, Hes1, TGF-β1 and FN was up-regulated in high glucose group (all P ＜ 0.05).Compared with that in high-glucose group, DAPT and cordyceps sinensis inhibited high glucose-induced mesangial cell proliferation and down-regulated the mRNA and protein expression of Notch pathway, TGF-β1 and FN (all P ＜ 0.05).Conclusion By inhibiting the abnormal activation of Notch signaling pathway and TGF-β signaling pathway, cordyceps sinensis may alleviate high glucose-induced mesangial cell proliferation and reduce extracellular matrix accumulation, thus protecting kidney.
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Objective To investigate the effect of microRNA (miRNA )‐548ah targeting histone deacetylase‐4 (HDAC4) on the replication and expression of hepatitis B virus (HBV) .Methods HepG2 , 2 ,15 cells were transfected by mimics and inhibitors . The expressions of miRNA‐548ah and HDAC4 before and after transfection were detected by fluorescent quantitative polymerase chain reaction (PCR) . The expression of HDAC4 protein in HepG2 ,2 ,15 cells was detected by Western blotting .The target gene of miRNA‐548ah was analyzed by bioinformatics methods .3′UTR dual‐luciferase expression vector containing candidate HDAC4 target genes was built to test the luciferase activity .The levels of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) in the supernatant of cultured HepG2 ,2 ,15 cells were detected by enzyme‐linked immunosorbent assay (ELISA) .The level of HBV DNA in the supernatant of HepG2 ,2 ,15 cells was detected by fluorescent quantitative PCR .The t‐test was used for comparison between two groups ,SNK‐q tests were used for multiple groups comparisons .Results The expressions of miRNA‐548ah in HepG2 ,2 ,15 and HepG2 cells were 5 .74 ± 0 .02 and 2 .96 ± 0 .40 , respectively (t= 11 .89 ,P< 0 .01) ,and the expressions of HDAC4 mRNA were 9 .38 ± 0 .39 and 18 .13 ±0 .34 ,respectively (t = 29 .39 , P < 0 .01) . The expression of miRNA‐548ah in HepG2 ,2 ,15 cells was inhibited by transfection of miRNA‐548ah inhibitors (1 .01 ± 0 .13 ,t= 15 .48 , P< 0 .01) .Compared with control group ,the levels of HBsAg ([6 .45 ± 0 .46 ] IU/mL vs [2 .60 ± 0 .20 ] IU/mL , t = 7 .48 , P <0 .01) ,HBeAg ([5 .49 ± 0 .27] NCU/mL vs [4 .15 ± 0 .34 ] NCU/mL , t = 3 .10 , P < 0 .05 ) and HBV DNA ([3 .93 ± 0 .06] lg copy/mL vs[2 .04 ± 0 .07] lg copy/mL ,t = 18 .89 , P< 0 .01) in the supernatant of cultured HepG2 ,2 ,15 cells significantly decreased in inhibitor group . The expression of HDAC4 in HepG2 ,2 ,15 cells significantly decreased after transfection of miRNA‐548ah mimics (2 .98 ± 0 .94) ,but significantly increased after transfection of miRNA‐548ah inhibitors (23 .77 ± 6 .74 ) , with statistical significance (F= 9 .34 , P< 0 .01) .The expression of HDAC4 protein was also significantly inhibited after transfection of miRNA‐548ah mimics (0 .53 ± 0 .14 vs 0 .23 ± 0 .02 , t = 3 .58 , P = 0 .02) .The activity of luciferase was significantly inhibited by transfection of miRNA‐548ah mimics (7 .62 ± 0 .45 vs 6 .65 ±0 .27 ,t = 3 .18 , P = 0 .03 ) .Conclusion miRNA‐548ah may promote the replication and expression of HBV through the regulation of target gene HDAC4 .
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Objective To investigate the underlying mechanism of ursolic acid in attenuating diabetic mesangial cells injury induced by high glucose (HG).Methods Rat glomerular mesangial cells were cultured in normal glucose,HG,HG with LY294002 and HG with ursolic acid.The cell proliferation and hypertrophy were detected by MTT and the ratio of total protein content to cell number.miRNA-21 was detected by quantitative real-time PCR.The PI3K-Akt-mTOR pathway,autophagy associated protein and collagen I were detected by Western blotting and quantitative realtime PCR.The autophagosomes were observed by electron microscope.Results Compared with normal control group,the cells exposed to HG showed up-regulating miRNA-21 expression(P ＜ 0.01),down-regulating PTEN protein and mRNA expression(P ＜ 0.01),up-regulating p85PI3K,phospho(p)-Akt,p-mTOR,p62/SQSTMI,collagen I expressions and down-regulating LC3II expression(P ＜ 0.01).Ursolic acid and LY294002 inhibited HG-induced mesangial cell hypertrophy and proliferation(P < 0.01),down -regulated the expressions of p85Pl3K,p-Akt,p-mTOR,p62/SQSTMI and collagen I and up-regulated the expression of LC3II(P ＜ 0.01).But LY294002 had no effect on the expression of miRNA-21 and PTEN.Ursolic acid down-regulated miRNA-21 expression(P ＜ 0.01),up-regulated PTEN protein and mRNA expression(P ＜ 0.01).Conclusion Ursolic acid may inhibit high glucose-induced mesangial cell miRNA-21 overexpression,up-regulate PTEN,inhibit the activation of PI3K-Akt-mTOR signaling pathway and the enhanced autophagy to reduce the accumulation of extracellular matrix and ameliorate cell hypertrophy and proliferation.