Wogonin protects glomerular podocytes by targeting Bcl-2-mediated autophagy and apoptosis in diabetic kidney disease

Abstract

Diabetic kidney disease (DKD) is one of the microvascular complications of diabetes mellitus and a major cause of end-stage renal disease with limited treatment options. Wogonin is a flavonoid derived from the root of Scutellaria baicalensis Georgi, which has shown a potent renoprotective effect. But the mechanisms of action in DKD are not fully elucidated. In this study, we investigated the effects of wogonin on glomerular podocytes in DKD using mouse podocyte clone 5 (MPC5) cells and diabetic mice model. MPC5 cells were treated with high glucose (30 mM). We showed that wogonin (4, 8, 16 μM) dose-dependently alleviated high glucose (HG)-induced MPC5 cell damage, accompanied by increased expression of WT-1, nephrin, and podocin proteins, and decreased expression of TNF-α, MCP-1, IL-1β as well as phosphorylated p65. Furthermore, wogonin treatment significantly inhibited HG-induced apoptosis in MPC5 cells. Wogonin reversed HG-suppressed autophagy in MPC5 cells, evidenced by increased ATG7, LC3-II, and Beclin-1 protein, and decreased p62 protein. We demonstrated that wogonin directly bound to Bcl-2 in MPC5 cells. In HG-treated MPC5 cells, knockdown of Bcl-2 abolished the beneficial effects of wogonin, whereas overexpression of Bcl-2 mimicked the protective effects of wogonin. Interestingly, we found that the expression of Bcl-2 was significantly decreased in biopsy renal tissue of diabetic nephropathy patients. In vivo experiments were conducted in STZ-induced diabetic mice, which were administered wogonin (10, 20, 40 mg · kg−1 · d−1, i.g.) every other day for 12 weeks. We showed that wogonin administration significantly alleviated albuminuria, histopathological lesions, and p65 NF-κB-mediated renal inflammatory response. Wogonin administration dose-dependently inhibited podocyte apoptosis and promoted podocyte autophagy in STZ-induced diabetic mice. This study for the first time demonstrates a novel action of wogonin in mitigating glomerulopathy and podocytes injury by regulating Bcl-2-mediated crosstalk between autophagy and apoptosis. Wogonin may be a potential therapeutic drug against DKD.

Research progress on the relationship between autophagy and chronic complications of diabetes

“…The hyperglycemic state of diabetic rats increases the accumulation and expression of Beclin-1 simultaneously promoting retinal Müller cell death in rats ( Lopes de Faria et al, 2016 ). Beclin-1 and Bcl-2 are interrelated and their binding downregulates Beclin-1-mediated autophagy in diabetic nephropathy ( Xu and Qin, 2019 ; Liu et al, 2022 ). TFEB, a regulatory factor, is associated with lysosomal biosynthesis.…”

Identification of Genes Reveals the Mechanism of Cell Ferroptosis in Diabetic Nephropathy

“…The STZ-induced DN model was established using C57/J male mice aged 6-8 weeks, which were divided into two groups: The DN group (n = 6) and NC group (n = 6). The modeling method was processed as previously described (Liu et al, 2021). Mice in the two groups were kept in standard environment for 12 weeks after the success of the diabetes model.…”

“…Paraffin sections of the kidney tissue were dewaxed, repaired as previous (Liu et al, 2021), and then incubated with the primary antibody overnight at 4 °C after antigen blocking with hydrogen peroxide and 10% BSA, followed by application of the secondary antibody at 37 °C for 1 h. ImageJ software was used for IHC analysis.…”

“…Total RNA was extracted and then reverse transcribed into cDNA as previously done (He et al, 2019;Liu et al, 2021). The cDNA was amplified using a T100 thermal cycler (Bio-Rad, Hercules, CA, United States).…”

Recent Advances in Clinical Diagnosis and Pharmacotherapy Options of Membranous Nephropathy

“…Natural products or traditional Chinese medicines have been long used in patients and considered an alternative therapeutic strategy for prevention and treatment of glomerular-associated diseases including MN ( Feng et al, 2020 ), glomerulonephritis ( Gianassi et al, 2019 ; Wang et al, 2021 ), diabetes ( Chen et al, 2020b ; Wang et al, 2020b ; Fang et al, 2021 ; Su et al, 2021 ; He et al, 2022 ), and diabetic nephropathy ( Li et al, 2020a ; Yang et al, 2020 ; Wang, 2021 ; Xuan et al, 2021 ; Yang and Wu, 2021 ; Zhou et al, 2021 ; Liu et al, 2022 ). Earlier finding have demonstrated that a 77-year-old woman with IMN was treated by Astragalus membranaceus and achieved clinical remission without using immunosuppressive therapy ( Ahmed et al, 2007 ).…”