Emodin Ameliorates High Glucose-Induced Podocyte Apoptosis via Regulating AMPK/mTOR-Mediated Autophagy Signaling Pathway / 中国结合医学杂志

OBJECTIVE@#To investigate the effect of emodin on high glucose (HG)-induced podocyte apoptosis and whether the potential anti-apoptotic mechanism of emodin is related to induction of adenosine-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)-mediated autophagy in podocytes (MPC5 cells) in vitro.@*METHODS@#MPC5 cells were treated with different concentrations of HG (2.5, 5, 10, 20, 40, 80 and 160 mmol/L), emodin (2, 4, 8 µ mol/L), or HG (40 mmol/L) and emodin (4 µ mol/L) with or without rapamycin (Rap, 100 nmol/L) and compound C (10 µ mol/L). The viability and apoptosis of MPC5 cells were detected using cell counting kit-8 (CCK-8) assay and flow cytometry analysis, respectively. The expression levels of cleaved caspase-3, autophagy marker light chain 3 (LC3) I/II, and AMPK/mTOR signaling pathway-related proteins were determined by Western blot. The changes of morphology and RFP-LC3 fluorescence were observed under microscopy.@*RESULTS@#HG at 20, 40, 80 and 160 mmol/L dose-dependently induced cell apoptosis in MPC5 cells, whereas emodin (4 µ mol/L) significantly ameliorated HG-induced cell apoptosis and caspase-3 cleavage (P<0.01). Emodin (4 µ mol/L) significantly increased LC3-II protein expression levels and induced RFP-LC3-containing punctate structures in MPC5 cells (P<0.01). Furthermore, the protective effects of emodin were mimicked by rapamycin (100 nmol/L). Moreover, emodin increased the phosphorylation of AMPK and suppressed the phosphorylation of mTOR. The AMPK inhibitor compound C (10 µ mol/L) reversed emodin-induced autophagy activation.@*CONCLUSION@#Emodin ameliorated HG-induced apoptosis of MPC5 cells in vitro that involved induction of autophagy through the AMPK/mTOR signaling pathway, which might provide a potential therapeutic option for diabetic nephropathy.

Jiangzhi Tongluo Soft Capsules Regulate SIRT1/FoxO3 Pathway to Affect Cell Apoptosis in Rats with Membranous Nephropathy / 中国实验方剂学杂志

ObjectiveTo observe the effect of Jiangzhi Tongluo soft capsule on the protein levels of silent mating-type information regulation 2 homolog 1 （SIRT1） and forkhead transcription factor FoxO3 and podocyte apoptosis in the renal tissue of rats with membranous nephropathy and to reveal the underlying molecular mechanisms for the treatment of MN. MethodSixty male SD rats were randomly assigned into 6 groups with 10 rats each. The six groups included a normal group， a model group， benazepril hydrochloride group， and Jiangzhi Tongluo soft capsule groups of low， medium and high doses （25， 50， 100 mg·kg-1， respectively）. The model rats were established by injection with cationized bovine serum albumin into the tail vein. After modeling， the rats were administrated with corresponding agents by gavage for 4 weeks. At the end of the 4th week， an electron microscope was used to observe the pathological changes in the kidney. Western blot was employed to detect the protein levels of SIRT1 and FoxO3 protein in rat kidney， and immunohistochemistry to detect the expression of B lymphocytoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， Bcl-2-associated death promoter （Bad）， and podocyte split diaphragm proteins nephrin and podocin. ResultCompared with normal group， the expression of pro-apoptotic factors Bax， Bad， and FoxO3 in the kidney was up-regulated （P<0.05）， while that of anti-apoptotic factors Bcl-2， SIRT1， nephrin， and podocin was down-regulated （P<0.05） after modeling. Compared with the model group， the treatments down-regulated the expression of Bax， Bad， and FoxO3 （P<0.05） and up-regulated that of Bcl-2， SIRT1， nephrin， and podocin （P<0.05）. ConclusionJiangzhi Tongluo soft capsule may regulate the SIRT1/FoxO3 pathway to reduce podocyte apoptosis and maintain podocyte structure stability， thereby exerting the renal protection effect.

Effects of berberine on high glucose-induced podocyte apoptosis and its related mechanism / 中国药理学通报

Aim To investigate the influence and char-acteristics of high glucose (HG) induced podocyte ap-optosis, and explore the protective effect of berberine on the apoptosis and the possible mechanism. Methods Mouse podocytes were cultured under different time and HG conditions to observe the effects of different glucose levels and time on podocyte apoptosis. The effect of berberine on podocyte activity was measured by CCK-8 assay. Meantime, the protective effect of berberine on podocyte apoptosis was detected by Ho-echst staining and flow cytometry. In addition, the effects of HG and berberine on the expression of apop-totic proteins and related signaling pathways in podocytes were analysed by laser confocal microscopy and Western blot. Results High glucose (15, 20, 25 and 30 mmol • L"1) could induce podocyte apoptosis at 72, 48, 36 and 24h, respectively. Berberine could increase the activity of podocytes cultured with high glu-cose, significantly reduce the apoptosis of podocytes induced by high glucose, down-regulate the expression of caspase-3,6,7,8 and 9 induced by high glucose, and increase the expression of Bcl-2. Conclusions The characteristics of podocyte apoptosis induced by different HG and time may provide important reference for clinical intervention of podocyte apoptosis and kid-ney injury. Berberine can alleviate the apoptosis of podocyte induced by high glucose, and its mechanism may be related to the apoptosis pathway of caspase-8/caspase-3 and Bcl-2/caspase-9/caspase-3 signaling pathways.