The m6A demethylase FTO promotes renal epithelial-mesenchymal transition by reducing the m6A modification of lncRNA GAS5

Cytokine. 2022 Nov:159:156000. doi: 10.1016/j.cyto.2022.156000. Epub 2022 Sep 1.

Abstract

Background: Renal interstitial fibrosis (RIF) is the main pathological change of a variety of chronic kidney diseases (CKD). Epigenetic modifications of fibrosis-prone genes regulate RIF progression. This study aimed to investigate long non-coding RNA (lncRNA) N6-methyladenosine (m6A) modification and its role in regulating RIF progression.

Methods: Unilateral ureteral occlusion (UUO) was employed to construct the RIF in vivo model; and TGF-β1-treated HK-2 and HKC-8 cells were used for in vitro experiments. The mRNA and protein expressions were assessed using qRT-PCR and western blot. The proliferation and migration were evaluated by EdU assay and transwell assay, respectively. In addition, levels of inflammatory cytokines were determined by ELISA assay and qRT-PCR. Moreover, lncRNA GAS5 m6A level was detected using Me-RIP assay. HE and Masson staining were employed to evaluate fibrotic lesions of the kidney.

Results: FTO expression was elevated in HK-2 and HKC-8 cells after TGF-β1 treatment and mouse kidney tissue following UUO, and lncRNA GAS5 was downregulated. LncRNA GAS5 overexpression or FTO silencing suppressed TGF-β1-induced the increase of EMT-related proteins (Vimentin, Snail and N-cadherin) and inflammatory cytokines (IL-6, IL-1β and TNF-α) levels in HK-2 cells. FTO suppressed lncRNA GAS5 expression by reducing the m6A modification of lncRNA GAS5. Additionally, FTO knockdown could suppress EMT process and inflammation response induced by TGF-β1 and UUO in vitro and in vivo. As expected, FTO knockdown abrogated the promotion effects of lncRNA GAS5 silencing on TGF-β1-induced EMT process and inflammation response in HK-2 and HKC-8 cells.

Conclusion: FTO promoted EMT process and inflammation response through reducing the m6A modification of lncRNA GAS5.

Keywords: EMT; FTO; Inflammation; M(6)A modification; Renal interstitial fibrosis; lncRNA GAS5.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alpha-Ketoglutarate-Dependent Dioxygenase FTO / genetics
  • Animals
  • Cadherins
  • Epithelial-Mesenchymal Transition / genetics
  • Fibrosis
  • Inflammation / genetics
  • Inflammation / pathology
  • Interleukin-6 / pharmacology
  • Kidney / metabolism
  • Mice
  • RNA, Long Noncoding* / genetics
  • RNA, Long Noncoding* / metabolism
  • RNA, Messenger
  • Renal Insufficiency, Chronic* / genetics
  • Renal Insufficiency, Chronic* / pathology
  • Transforming Growth Factor beta1 / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology
  • Ureteral Obstruction* / genetics
  • Ureteral Obstruction* / metabolism
  • Vimentin

Substances

  • Cadherins
  • Interleukin-6
  • RNA, Long Noncoding
  • RNA, Messenger
  • Transforming Growth Factor beta1
  • Tumor Necrosis Factor-alpha
  • Vimentin
  • FTO protein, mouse
  • Alpha-Ketoglutarate-Dependent Dioxygenase FTO