[Effect of adenovirus-mediated shRNA down-regulates SHP2 expression on the apoptosis of human hepatic stellate cells LX-2].

Objective: To investigate the effect of adenovirus-mediated short hairpin RNA (shRNA) downregulating SH2 domain-containing protein tyrosine phosphatase 2 (SHP2) on the apoptosis of human hepatic stellate cells LX-2 cultured in vitro. Methods: The recombinant adenovirus Ad-shRNA/SHP2 carrying shRNA targeted SHP2 and expressing green fluorescent protein (GFP), and the empty control virus Ad-GFP expressing GFP were transfected into LX-2 cells cultured in vitro. Real-time fluorescence quantitative PCR was used to detect SHP2 mRNA expression in LX-2 cells. Western blot was used to detect the protein expressions of SHP2, Bax, and Bcl-2 in LX-2 cells. TUNEL and annexin-V/propidium iodide dual-labeled flow cytometry were used to detect apoptosis in LX-2 cells. Experimental group: (1) Control group: LX-2 cells were transfected with DMEM instead of adenovirus; (2) Ad-GFP group: transfected with empty virus Ad-GFP; (3) Ad-shRNA/SHP2 group: transfected with recombinant adenovirus Ad-shRNA/SHP2. The means between multiple groups were compared using a one-way ANOVA and the LSD test was used for inter group comparisons. Results: shRNA-targeted SHP2 significantly down-regulated the expression of SHP2 protein and mRNA in LX-2 cells (P < 0.05). The TUNEL and annexin-V/propidium iodide dual-labeled flow cytometry results showed that the apoptosis rate of LX-2 cells in the Ad-shRNA/SHP2 group (12.755%±1.606%, 19.340%±2.505%) (P < 0.05) was significantly higher compared to the control group (3.077%±0.731%, 9.438%±0.804%) and the Ad-GFP group (3.250%±0.851%, 8.893%±1.982%), with no statistically significant difference between the control group and the Ad-GFP group (P > 0.05). Western blot analysis of Bax and Bcl-2 protein expression in LX-2 cells of each group revealed that the Bax protein expression was significantly higher in the Ad shRNA/SHP2 group (2.493 ± 0.203) (P < 0.05) compared to the control group and Ad-GFP group (1.989 ± 0.147, 1.999 ± 0.162), with no statistically significant difference between the control group and the Ad-GFP group (P > 0.05), while the Bcl-2 protein was significantly decreased in the Ad-shRNA/SHP2 group (1.042±0.148) compared with the control group and the Ad-GFP group (1.707±0.146, 1.521±0.142), with no statistically significant difference between the control group and the Ad-GFP group (P > 0.05). Conclusions: SHP2 expression down-regulation induces apoptosis of human hepatic stellate cells LX-2 in vitro by reducing Bcl-2/Bax.

Regulatory mechanism of TGF-ß1/SGK1 pathway in tubulointerstitial fibrosis of diabetic nephropathy.

OBJECTIVE: The aim of this study was to clarify the potential function of transforming growth factor-ß1/serum/glucocorticoid-regulated kinase 1 (TGF-ß1/SGK1) pathway in diabetic nephropathy-induced tubulointerstitial fibrosis. MATERIALS AND METHODS: Type 2 diabetes mellitus (T2DM) model was successfully established in rats by high-sucrose-high-fat diet combined with streptozotocin (STZ) induction. Subsequently, blood glucose level, renal function and pathological changes in kidneys of T2DM and control rats were evaluated. Western blot and quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) were conducted to determine the protein and mRNA expression levels of TGF-ß1, SGK1, fibronectin (FN) and α-smooth muscle actin (α-SMA) in rat kidney tissues, respectively. RESULTS: Blood glucose (BG), glycosylated hemoglobin (GHb), serum creatinine (Scr) and blood urea nitrogen (BUN) in T2DM rats were significantly higher than those of control rats (p<0.05). The morphology of glomeruli and renal tubules in rats of control group were normal. In contrast, T2DM rats showed significant lesions in glomeruli, renal tubules, and renal interstitium. Furthermore, the relative expression levels of TGF-ß1, SGK1, FN, and α-SMA in kidney tissues of T2DM rats were remarkably higher than those of controls (p<0.05). CONCLUSIONS: The TGF-ß1/SGK1 pathway is closely related to tubulointerstitial fibrosis in T2DM rats.