Mechanism of abnormal methylation of histone H3K27 inducing podocyte damage in focal segmental glomerulosclerosis mice
10.3760/cma.j.cn441217-20240625-00638
- VernacularTitle:组蛋白H3K27甲基化异常修饰致局灶节段性肾小球硬化小鼠足细胞损伤的作用机制
- Author:
Yanzi ZHANG
1
;
Fengjuan GU
;
Xiaolu SUI
;
Yunpeng XU
;
Aisha ZHANG
;
Tingfei XIE
;
Jiahui CHEN
;
Jihong CHEN
Author Information
1. 深圳大学第二附属医院 深圳市宝安区人民医院肾内科，深圳 518000
- Publication Type:Journal Article
- Keywords:
Histones;
Podocytes;
Glomerulosclerosis, focal segmental;
JAK2-STAT3 signaling pathway
- From:
Chinese Journal of Nephrology
2025;41(1):38-48
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the target signaling pathway of histone H3K27 methylation-induced podocyte injury, verify the regulatory effect of histone H3K27 methylation on podocyte injury in focal segmental glomerulosclerosis (FSGS) mice through target signaling pathway, and explore the mechanism of abnormal methylation of histone H3K27-induced podocyte injury in FSGS mice.Methods:(1) Cell experiments: primary cultured immortalized mouse podocytes MPC5 were cultured in vitro, and divided into control group, adriamycin (ADR) group, ADR+GSK-J4 (histone demethylase, KDM6B inhibitor) group, ADR+coumarin A1 (C-A1, JAK2 agonist) group and ADR+GSK-J4+C-A1 group. The transmission electron microscope was used to observe ultrastructure of podocytes. Immunofluorescence was used to detect the protein expression of H3K27me3 and nephrin in podocytes. The whole genome sequence of podocytes was obtained, the differentially expressed genes were screened, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used for enrichment analysis. Real time-quantitative PCR and Western blotting were used to detect the gene and protein expression of JAK2-STAT3 signaling pathway in podocytes respectively. Enzyme-linked immunosorbent assay was used to detect interleukin 6 (IL-6), monocyte chemotactic protein 1 (MCP-1), α-smooth muscle actin (α-SMA) and transforming growth factor β1 (TGF-β1). (2) Animal experiments: EZH2 gene knock out ( EZH2podKo)-FSGS (tail vein injection of ADR) mouse models were established, and divided into EZH2ctrl+control group ( n=20), EZH2ctrl+FSGS ( n=20), EZH2podKo+control group ( n=30) and EZH2podKo+FSGS group ( n=30). HE staining was used to observe the morphology of kidney tissues. Immunohistochemistry was used to detect the H3K27me3 protein expression in podocytes. Real time-quantitative PCR and Western blotting were used to verify the gene and protein expression of JAK2-STAT3 signaling pathway respectively. Enzyme-linked immunosorbent assay was used to detect IL-6, MCP-1, α-SMA and TGF-β1 of kidney tissues. Results:(1) Cell experiments: Compared with control group, the nucleus shrank and ruptured, the cytoplasm showed vacuole, and mitochondria and endoplasmic reticulum swelled in ADR group, which verified that the podocyte injury model of ADR nephropathy was successfully established. Compared with control group, the protein expression level of H3K27me3 in ADR group was significantly lower ( P<0.05). Compared with ADR group, the protein expression level of H3K27me3 in podocytes in ADR+GSK-J4 group was significantly higher ( P<0.05), and there were 502 increased genes and 443 decreased genes. GO enrichment analysis showed that the differentially enriched peaks were mainly in ribonucleoprotein complex biogenesis, ribosome biogenesis, establishment of protein localization to organelle, and involved in regulation of receptor signaling pathway via JAK-STAT and receptor signaling pathway via JAK-STAT. Differential expressed genes were Irf1, Tnfrsf1a, S ocs1, Notch1, Gadd45a, Hes1 and Socs3, involving in the regulation of JAK-STAT signaling pathway. KEGG enrichment analysis showed that the differentially enriched peaks were mainly in amyotrophic lateral sclerosis, and the target genes were Mcl1, Egfr, Socs1, Cdkn1a, Pdgfa and Socs3, involving in the regulation of JAK-STAT signaling pathway. Compared with ADR group, the mRNA and protein expression levels of JAK2 and STAT3 in the ADR+GSK-J4 group were significantly lower, and the downstream inflammatory factors of IL-6, MCP-1 and α-SMA were significantly higher (all P<0.05). Compared with ADR group, the protein expression level of nephrin in ADR+GSK-J4 group was higher ( P<0.05), and the protein expression level of nephrin in ADR+C-A1 group was lower ( P<0.05). Compared with ADR+GSK-J4 group, the protein expression level of nephrin in ADR+GSK-J4+C-A1 group was lower ( P<0.05). (2) Animal experiments: Compared with EZH2ctrl+FSGS group, EZH2podKo+FSGS group showed obvious renal tissue damage, matrix hyperplasia in mesangial area with massive homogeneous substance deposition, apoptosis and necrosis of renal tubular epithelial cells, obvious thickening and extensive fusion of glomerular epithelial cells, basement membrane collapse, and compression and narrowing of capillary structure. Compared with EZH2ctrl+FSGS group, the protein expression level of H3K27me3 in EZH2podKo+FSGS group was significantly lower, and the mRNA and protein expression levels of JAK2 and STAT3, and the levels of IL-6, MCP-1, α-SMA and TGF-β1 were higher (all P<0.05). Conclusions:Abnormal methylation modification of H3K27 leads to change of target gene expression, activation of JAK2-STAT3 signaling pathway, podocyte injury, glomerulosclerosis and renal tubular injury, participating in the development of FSGS.
