Downregulating lncRNA MIAT attenuates apoptosis of podocytes exposed to high glucose

Acta Diabetol. 2024 Apr;61(4):451-460. doi: 10.1007/s00592-023-02213-w. Epub 2023 Dec 11.

Abstract

Aims: Diabetic nephropathy (DN), a destructive complication of diabetes mellitus (DM), is one of the leading causes of end-stage renal disease (ESRD). This study aimed to investigate the role of long non-coding RNA (lncRNA) MIAT in high-glucose (HG)-induced podocyte injury associated with DN.

Methods: Three human kidney podocyte (HKP) cultures were treated with HG to mimic DN. Expression of lncRNA MIAT, podocyte-specific and injury-related proteins, and apoptosis were assessed before and after MIAT knockdown using MIAT shRNAs.

Results: MIAT expression was upregulated in HKPs in response to glucose stress. HG treatment resulted in a significant increase in the apoptotic rate, Bax level, and levels of injury-related proteins desmin, fibroblast-specific protein 1 (FSP-1), and smooth muscle α-actin (α-SMA), and a significant reduction in Bcl-2 levels and the levels of podocyte-specific proteins synaptopodin and podocin. Transfection of HKPs with shRNAs significantly reduced MIAT levels (p < 0.05) and attenuated apoptosis in HG-medium. Correspondingly, the levels of synaptopodin and podocin were upregulated, and desmin, FSP-1, and α-SMA were reduced (p < 0.05). Western blot analysis also showed that anti-apoptotic active caspase-3 and Bax and proapoptotic Bcl-2 were elevated and decreased, respectively, after MIAT knockdown, suggesting that apoptosis pathways are deactivated after MIAT downregulation.

Conclusions: High glucose upregulates MIAT level in HKPs and induces cellular injury. Knockdown of MIAT alleviates the injury likely via deactivating apoptosis pathways.

Keywords: Apoptosis; Diabetic nephropathy; High glucose; Podocyte; Synaptopodin; lncRNA MIAT.

MeSH terms

  • Apoptosis / genetics
  • Desmin / genetics
  • Desmin / metabolism
  • Diabetic Nephropathies* / genetics
  • Diabetic Nephropathies* / metabolism
  • Glucose / metabolism
  • Glucose / pharmacology
  • Humans
  • Podocytes*
  • RNA, Long Noncoding* / genetics
  • RNA, Long Noncoding* / metabolism
  • bcl-2-Associated X Protein / genetics
  • bcl-2-Associated X Protein / metabolism

Substances

  • RNA, Long Noncoding
  • Desmin
  • bcl-2-Associated X Protein
  • Glucose