Stage-specific dual function: EZH2 regulates human erythropoiesis by eliciting histone and non-histone methylation

Haematologica. 2023 Sep 1;108(9):2487-2502. doi: 10.3324/haematol.2022.282016.

Abstract

Enhancer of zeste homolog 2 (EZH2) is the lysine methyltransferase of polycomb repressive complex 2 (PRC2) that catalyzes H3K27 tri-methylation. Aberrant expression and loss-of-function mutations of EZH2 have been demonstrated to be tightly associated with the pathogenesis of various myeloid malignancies characterized by ineffective erythropoiesis, such as myelodysplastic syndrome (MDS). However, the function and mechanism of EZH2 in human erythropoiesis still remains largely unknown. Here, we demonstrated that EZH2 regulates human erythropoiesis in a stage-specific, dual-function manner by catalyzing histone and non-histone methylation. During the early erythropoiesis, EZH2 deficiency caused cell cycle arrest in the G1 phase, which impaired cell growth and differentiation. Chromatin immunoprecipitation sequencing and RNA sequencing discovered that EZH2 knockdown caused a reduction of H3K27me3 and upregulation of cell cycle proteindependent kinase inhibitors. In contrast, EZH2 deficiency led to the generation of abnormal nuclear cells and impaired enucleation during the terminal erythropoiesis. Interestingly, EZH2 deficiency downregulated the methylation of HSP70 by directly interacting with HSP70. RNA-sequencing analysis revealed that the expression of AURKB was significantly downregulated in response to EZH2 deficiency. Furthermore, treatment with an AURKB inhibitor and small hairpin RNAmediated AURKB knockdown also led to nuclear malformation and decreased enucleation efficiency. These findings strongly suggest that EZH2 regulates terminal erythropoiesis through a HSP70 methylation-AURKB axis. Our findings have implications for improved understanding of ineffective erythropoiesis with EZH2 dysfunction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Enhancer of Zeste Homolog 2 Protein* / genetics
  • Erythropoiesis* / genetics
  • Histones* / metabolism
  • Humans
  • Methylation
  • Polycomb Repressive Complex 2 / genetics
  • Polycomb Repressive Complex 2 / metabolism

Substances

  • Enhancer of Zeste Homolog 2 Protein
  • EZH2 protein, human
  • Histones
  • Polycomb Repressive Complex 2

Grants and funding

Funding: This work was supported, in part, by grants from the Natural Science Foundation of China (82170116, 81870094, 81870093, 81900112 and 82000121), the Program for Science & Technology Innovation Talents in Universities of Henan Province (20HASTIT039), the Key Scientific and Technological Research Projects in Henan Province (222102310012) and 2021 science and technology development plan of the Henan Province (212102310037).