PTGDS Aggravates Cellular Senescence of Podocytes in Diabetic Kidney Disease by Activating NF-κB Signaling Pathway

Background: Diabetic kidney disease (DKD) is a leading cause of renal failure, and podocyte injury plays a critical role in its progression. In our prior study, we utilized single-cell RNA sequencing to analyze renal samples from DKD patients and observed that prostaglandin D2 synthase (PTGDS) was the most upregulated gene in podocyte of DKD. Nevertheless, the role of PTGDS in podocyte injury within DKD remains unclear. Methods: Real-time PCR and immunofluorescence were employed to evaluate the expression of PTGDS both in vitro and in vivo. Western blot and immunofluorescence were used to assess podocyte injury. Senescence-associated secretory phenotypes (SASPs) and cell cycle-related molecules were analyzed using western blot and real-time PCR, and β-galactosidase and γ-H2A.X staining were used to evaluate the extent of cellular senescence. The localization of NF-κB was determined using immunofluorescence analysis and nuclear and cytoplasmic protein extraction assay. The role of signal transducer and activator of transcription 1 (STAT1) in the regulation of PTGDS transcription was determined by luciferase reporter assay and chromatin immunoprecipitation assay. Podocyte-specific AAV9 harboring shPTGDS mice were established to observe kidney injury in vivo. Results: PTGDS was significantly increased in podocytes under high glucose (HG) conditions. Knockdown of PTGDS attenuate high glucose-induced podocyte senescence and injury, while its overexpression aggravated these responses. Mechanistically, we demonstrated that STAT1 upregulated the expression of PTGDS, and then induced nuclear translocation of NF-κB, accelerating the transcription of SASP factors and podocyte injury. We also demonstrated that NF-κB inhibitor JSH23 mitigated podocyte senescence and injury induced by PTGDS. In addition, podocyte-specific deletion of PTGDS alleviated podocyte and glomerular injury in STZ-induced diabetic mice. Conclusion: These findings indicate that STAT1-induced PTGDS upregulation promotes podocyte senescence and injury through activation of the NF-κB signaling pathway in DKD. Funding: Government Support – Non-U.S.