Resveratrol protects podocytes against apoptosis via stimulation of autophagy in a mouse model of diabetic nephropathy.

Podocyte apoptosis coincides with albuminuria onset and precedes podocytopenia in diabetic nephropathy. However, there is a lack of effective therapeutic drugs to protect podocytes from apoptosis. Here, we demonstrated that resveratrol relieved a series of indicators of diabetic nephropathy and attenuated apoptosis of podocytes in db/db diabetic model mice. In addition, resveratrol induced autophagy in both db/db mice and human podocytes. Furthermore, inhibition of autophagy by 3-methyladenine (3-MA) and autophagy gene 5 (Atg5) short hairpin RNA (shRNA) reversed the protective effects of resveratrol on podocytes. Finally, we found that resveratrol might regulate autophagy and apoptosis in db/db mice and podocytes through the suppression of microRNA-383-5p (miR-383-5p). Together, our results indicate that resveratrol effectively attenuates high glucose-induced apoptosis via the activation of autophagy in db/db mice and podocytes, which involves miR-383-5p. Thus, this study reveals a new possible strategy to treat diabetic nephropathy.

Heat shock protein 70-2 and tumor necrosis factor-α gene polymorphisms in Chinese children with Henoch-Schönlein purpura.

BACKGROUND: Henoch-Schönlein purpura (HSP) or IgA-associated vasculitis is related to immune disturbances. Polymorphisms of the heat shock protein 70-2 gene (HSP70-2) and the tumor necrosis factor-a gene (TNF-α) are known to be associated with immune diseases. The purpose of this study was to investigate the likely association of HSP70-2 (+1267A/G) and TNF-α (+308A/G) gene polymorphisms with HSP in children. METHODS: The polymerase chain reaction restriction fragment length polymorphism method was used to detect the HSP70-2 and TNF-α polymorphisms in 205 cases of children with HSP and 53 controls; and the association of these polymorphisms with HSP and HSP nephritis (HSPN) was analyzed. RESULTS: The G/G genotypic frequencies at the +1267A/G position of HSP70-2 in the HSP group (22.9%) were significantly higher than those in the healthy control group (9.4%) (χ(2)=4.764, P<0.05). The frequencies of the A/A, A/G and G/G genotypes of HSP70-2 in patients in the nephritis-free group and the HSPN group showed no statistically significant difference. The A/A genotype frequency at the +308G/A position of TNF-α in the HSP group was 8.3%, which was higher than that in the control group (χ(2)=6.447, P<0.05). The A allele frequency of TNF-α in the HSP group was higher than that in the control group, with a statistically significant difference (χ(2)=7.241, P<0.05). CONCLUSIONS: The HSP70-2 (+1267A/G) and TNF-α (+308G/A) gene polymorphisms were associated with HSP in children. The G/G homozygosity of HSP70-2 and the A/A homozygosity of TNF-α may be genetic predisposing factors for HSP.

Pretreatment with the total flavone glycosides of Flos Abelmoschus manihot and hyperoside prevents glomerular podocyte apoptosis in streptozotocin-induced diabetic nephropathy.

Diabetic nephropathy (DN) is an important diabetic complication, and podocyte apoptosis plays a critical role in the development of DN. In the present study, we examined the preventive effect of the total flavone glycosides of Flos Abelmoschus manihot (TFA) on urinary microalbumin and glomerular podocyte apoptosis in experimental DN rats. The preliminary oral administration of TFA (200 mg/kg/day) for 24 weeks significantly decreased the urinary microalbumin to creatinine ratio and 24-h urinary total protein in streptozotocin-induced DN rats. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay indicated glomerular cell apoptosis in DN rats was significantly improved by pretreatment with TFA. Furthermore, fluorescence-activated cell sorting and Hoechst 33342 staining suggested preincubation with hyperoside (50 and 200 µg/mL), the major active constituent of TFA, could significantly mitigate cultured podocyte apoptosis induced by the advanced glycation end-products (AGEs). Western blot analysis showed that increased caspase-3 and caspase-8 expressions induced by AGEs were also inhibited by pretreatment with hyperoside at both doses. Our results demonstrate that TFA pretreatment can decrease urinary albumin excretion in early-stage DN, which might be accomplished by preventing renal damage and podocyte apoptosis.