Suppression of EZH2 inhibits TGF-β1-induced EMT in human retinal pigment epithelial cells

  • Exp Eye Res. 2022 Sep;222:109158. doi: 10.1016/j.exer.2022.109158.
Yu Peng  1 ,  Kai Liao  2 ,  Feng Tan  1 ,  Yuqin Liang  1 ,  Xihao Sun  1 ,  Zekai Cui  3 ,  Bo Ye  4 ,  Zhongping Chen  5 ,  Shibo Tang  6 ,  Jiansu Chen  7
Affiliations
  • 1. Aier School of Ophthalmology, Central South University, Changsha, Hunan, China; Aier Eye Institute, Changsha, Hunan Province, China.
  • 2. State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
  • 3. Aier School of Ophthalmology, Central South University, Changsha, Hunan, China; Aier Eye Institute, Changsha, Hunan Province, China; Nanchang Aier Eye Hospital, Nanchang, Jiangxi Province, China.
  • 4. Changsha Aier Eye Hospital, Changsha, Hunan Province, China.
  • 5. Aier School of Ophthalmology, Central South University, Changsha, Hunan, China; Changsha Aier Eye Hospital, Changsha, Hunan Province, China.
  • 6. Aier School of Ophthalmology, Central South University, Changsha, Hunan, China; Aier Eye Institute, Changsha, Hunan Province, China; CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China. Electronic address: [email protected].
  • 7. Aier School of Ophthalmology, Central South University, Changsha, Hunan, China; Aier Eye Institute, Changsha, Hunan Province, China; Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China. Electronic address: [email protected].
PMID: 35780904 DOI: 10.1016/j.exer.2022.109158
Abstract

Epithelial-mesenchymal transition (EMT) of retinal pigment epithelium (RPE) cells is critically involved in the occurrence of subretinal fibrosis. This study aimed to investigate the role of enhancer of zeste homolog 2 (EZH2) in EMT of human primary RPE cells and the underlying mechanisms of the anti-fibrotic effect of EZH2 suppression. Primary cultures of human RPE cells were treated with TGF-β1 for EMT induction. EZH2 was silenced by siRNA to assess the expression levels of epithelial and fibrotic markers using qRT-PCR, Western blot, and immunofluorescence staining assay. Furthermore, the cellular migration, proliferation and barrier function of RPE cells were evaluated. RNA-sequencing analyses were performed to investigate the underlying mechanisms of EZH2 inhibition. Herein, EZH2 silencing up-regulated epithelial marker ZO-1 and downregulated fibrotic ones including α-SMA, fibronectin, and Collagen 1, alleviating EMT induced by TGF-β1 in RPE cells. Moreover, silencing EZH2 inhibited cellular migration and proliferation, but didn't affect cell Apoptosis. Additionally, EZH2 suppression contributed to improved barrier functions after TGF-β1 stimulation. The results from RNA Sequencing suggested that the anti-fibrotic effect of EZH2 inhibition was associated with the MAPK signaling pathway, cytokine-cytokine receptor interaction, and the TGF-beta signaling pathway. Our findings provide evidence that the suppression of EZH2 might reverse EMT and maintain the functions of RPE cells. EZH2 could be a potential therapeutic avenue for subretinal fibrosis.

Keywords
EZH2; Epithelial–mesenchymal transition; Fibrosis; Retinal pigment epithelium.
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