TY - JOUR
T1 - P53 upregulated by HIF-1α promotes hypoxia-induced G2/M arrest and renal fibrosis in vitro and in vivo
AU - Liu, Limin
AU - Zhang, Peng
AU - Bai, Ming
AU - He, Lijie
AU - Zhang, Lei
AU - Liu, Ting
AU - Yang, Zhen
AU - Duan, Menglu
AU - Liu, Minna
AU - Liu, Baojian
AU - Du, Rui
AU - Qian, Qi
AU - Sun, Shiren
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (81670655, 81400699, and 81370789).
Funding Information:
We thank the International Society of Nephrology (ISN) for its support of the Trio-ISN Renal Sister Center, which makes ongoing collaborative work possible. We also thank Dr Zheng Dong, Dr Di Wang, and Mr Gang Wang for providing us the kidney cell lines and technical support. This work was supported by the National Natural Science Foundation of China (81670655, 81400699, and 81370789).
Publisher Copyright:
© 2018 The Author(s). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS. All rights reserved.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - Hypoxia plays an important role in the genesis and progression of renal fibrosis. The underlying mechanisms, however, have not been sufficiently elucidated. We examined the role of p53 in hypoxia-induced renal fibrosis in cell culture (human and rat renal tubular epithelial cells) and a mouse unilateral ureteral obstruction (UUO) model. Cell cycle of tubular cells was determined by flow cytometry, and the expression of profibrogenic factors was determined by RT-PCR, immunohistochemistry, and western blotting. Chromatin immunoprecipitation and luciferase reporter experiments were performed to explore the effect of HIF-1α on p53 expression. We showed that, in hypoxic tubular cells, p53 upregulation suppressed the expression of CDK1 and cyclins B1 and D1, leading to cell cycle (G2/M) arrest (or delay) and higher expression of TGF-β, CTGF, collagens, and fibronectin. p53 suppression by siRNA or by a specific p53 inhibitor (PIF-α) triggered opposite effects preventing the G2/M arrest and profibrotic changes. In vivo experiments in the UUO model revealed similar antifibrotic results following intraperitoneal administration of PIF-α (2.2 mg/kg). Using gain-of-function, loss-of-function, and luciferase assays, we further identified an HRE3 region on the p53 promoter as the HIF-1α-binding site. The HIF-1α-HRE3 binding resulted in a sharp transcriptional activation of p53. Collectively, we show the presence of a hypoxia-activated, p53-responsive profibrogenic pathway in the kidney. During hypoxia, p53 upregulation induced by HIF-1α suppresses cell cycle progression, leading to the accumulation of G2/M cells, and activates profibrotic TGF-β and CTGF-mediated signaling pathways, causing extracellular matrix production and renal fibrosis.
AB - Hypoxia plays an important role in the genesis and progression of renal fibrosis. The underlying mechanisms, however, have not been sufficiently elucidated. We examined the role of p53 in hypoxia-induced renal fibrosis in cell culture (human and rat renal tubular epithelial cells) and a mouse unilateral ureteral obstruction (UUO) model. Cell cycle of tubular cells was determined by flow cytometry, and the expression of profibrogenic factors was determined by RT-PCR, immunohistochemistry, and western blotting. Chromatin immunoprecipitation and luciferase reporter experiments were performed to explore the effect of HIF-1α on p53 expression. We showed that, in hypoxic tubular cells, p53 upregulation suppressed the expression of CDK1 and cyclins B1 and D1, leading to cell cycle (G2/M) arrest (or delay) and higher expression of TGF-β, CTGF, collagens, and fibronectin. p53 suppression by siRNA or by a specific p53 inhibitor (PIF-α) triggered opposite effects preventing the G2/M arrest and profibrotic changes. In vivo experiments in the UUO model revealed similar antifibrotic results following intraperitoneal administration of PIF-α (2.2 mg/kg). Using gain-of-function, loss-of-function, and luciferase assays, we further identified an HRE3 region on the p53 promoter as the HIF-1α-binding site. The HIF-1α-HRE3 binding resulted in a sharp transcriptional activation of p53. Collectively, we show the presence of a hypoxia-activated, p53-responsive profibrogenic pathway in the kidney. During hypoxia, p53 upregulation induced by HIF-1α suppresses cell cycle progression, leading to the accumulation of G2/M cells, and activates profibrotic TGF-β and CTGF-mediated signaling pathways, causing extracellular matrix production and renal fibrosis.
KW - HIF-1α
KW - TGF-β
KW - cell cycle (G2/M) arrest
KW - hypoxia
KW - p53
KW - renal tubulointerstitial fibrosis
UR - http://www.scopus.com/inward/record.url?scp=85067345691&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85067345691&partnerID=8YFLogxK
U2 - 10.1093/jmcb/mjy042
DO - 10.1093/jmcb/mjy042
M3 - Article
C2 - 30032308
AN - SCOPUS:85067345691
VL - 11
SP - 371
EP - 382
JO - Journal of Molecular Cell Biology
JF - Journal of Molecular Cell Biology
SN - 1674-2788
IS - 5
M1 - mjy042
ER -