High glucose stimulates oxidative stress and inflammatory response of glomerular mesangial cells in rats by regulating PINK1/Parkin pathway

  Objective  To explore the potential impact of high glucose stimulation on rat glomerular mesangial cells (RMCs).

  Methods  RMCs were treated with 5.5 and 30.0 mmol/L glucose, and the levels of PINK1 and Parkin mRNA were detected by real-time fluorescence quantitative PCR (RT-qPCR). The protein levels of PINK1, Parkin, translocase of outer mitochondrial membrane 20 (Tomm20) and LC3-Ⅱwere detected by Western blot. The colocalization of LC3-Ⅱand Tomm20 was detected by immunofluorescence technique. The level of reactive oxygen species (ROS) and apoptosis in RMCs were measured by flow cytometry. The release of inflammatory factors was detected by enzyme-linked immunosorbent assay and RT-qPCR. Regulating effect of nuclear factor κB (NF-κB) pathway was detected by Western blot.

  Results  After treatment of 30.0 mmol/L glucose, the PINK1 and Parkin mRNA had lower expression in RMCs, and the levels of PINK1 and Parkin proteins were also decreased. Meanwhile, the levels of LC3-Ⅱand Tomm20 proteins in RMCs were increased, while the co-expression signals of Tomm20 and LC3-Ⅱwere decreased significantly. After treatment by 30.0 mmol/L glucose, the ROS level, apoptosis rate and the concentrations and mRNA levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and transforming growth factor-β (TGF-β) were increased in RMCs. In RMCs treated with 30.0 mmol/L glucose, NF-κB pathway was activated.

  Conclusion  High glucose stimulation can not only promote the production of ROS and inflammatory response, but also can inhibit the PINK1/Parkin signaling pathway in RMCs. High glucose stimulation can affect the progression of diabetic nephropathy (DN) by regulating PINK1/Parkin mediated autophagy pathway.