Gasdermin D Protects Mouse Podocytes Against High-Glucose-Induced Inflammation and Apoptosis via the C-Jun N-Terminal Kinase (JNK) Pathway

Med Sci Monit. 2021 Mar 9:27:e928411. doi: 10.12659/MSM.928411.

Abstract

BACKGROUND The inflammation and apoptosis of podocytes contribute to the pathological progression of diabetic nephropathy. Gasdermin D (GSDMD) plays an executive role in pyroptosis, but its effect on high-glucose (HG)-induced inflammation and apoptosis remains unclear. The aim of this study was to investigate the effect of GSDMD on high-glucose-induced inflammation and apoptosis in podocytes. MATERIAL AND METHODS Mouse podocytes were cultivated by high- or normal-glucose medium. We used western blot analysis, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and immunofluorescence to detect the expression and localization of GSDMD in high-glucose-induced podocytes, and the expression of apoptosis-related proteins Bax and Bcl-2, inflammatory factors IL-1ß, IL-6, and TNF-alpha, and JNK pathways in high-glucose-induced podocytes. Western blot and immunofluorescence were used to detect the expression and localization of synaptopodin under GSDMD knockdown and JNK-specific blocker SP600125. MitoSOX Red was used to detect the production of ROS in mitochondria under siGSDMD. The intracellular ROS generation was detected using a reactive oxygen species assay kit. RESULTS We found that GSDMD knockdown and JNK inhibition reduced the expression of Bax, Bcl-2, cleaved caspase-3, IL-1ß, IL-6, and TNF-alpha. Our results showed that GSDMD knockdown can inhibit HG-induced mitochondrial ROS production and JNK phosphorylation. CONCLUSIONS This study indicates that GSDMD knockdown can attenuate HG-induced inflammation and apoptosis by inhibiting the phosphorylation of JNK via mitochondrial ROS.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis Regulatory Proteins / metabolism
  • Caspase 3
  • Cell Culture Techniques
  • Diabetic Nephropathies / metabolism
  • Glucose / metabolism
  • Inflammation
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Intracellular Signaling Peptides and Proteins / pharmacology*
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • MAP Kinase Signaling System / drug effects
  • Mice
  • Mitochondria / metabolism
  • Phosphate-Binding Proteins / metabolism*
  • Phosphate-Binding Proteins / pharmacology*
  • Podocytes / drug effects
  • Podocytes / metabolism*
  • Proto-Oncogene Proteins c-bcl-2
  • Pyroptosis / drug effects
  • Reactive Oxygen Species / metabolism
  • bcl-2-Associated X Protein

Substances

  • Apoptosis Regulatory Proteins
  • Bax protein, mouse
  • Gsdmd protein, mouse
  • Intracellular Signaling Peptides and Proteins
  • Phosphate-Binding Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Reactive Oxygen Species
  • bcl-2-Associated X Protein
  • JNK Mitogen-Activated Protein Kinases
  • Caspase 3
  • Glucose