EZH2 plays a crucial role in ischemia/reperfusion-induced acute kidney injury by regulating p38 signaling.
OBJECTIVE AND DESIGN
Renal ischemia-reperfusion (IR)-induced acute kidney injury (AKI) remains a major challenge in clinic. The histone methyltransferases enhancer of zest homolog-2 (EZH2) is associated with the development of renal injury. However, the molecular mechanism has not been fully elucidated.


MATERIALS
AKI in C57BL/6 mice was generated by renal IR.


TREATMENTS
The 3-deazaneplanocin A (DZNeP), a selective EZH2 inhibitor, or vehicle was administrated in mice after IR. HK-2 cells were exposed to hypoxia-reoxygenation (H/R) stress.


METHODS
Apoptosis was detected by TUNEL assay or flow cytometry. EZH2, caspase-3, p38, F4/80+ macrophages, and CD3+ T cells were examined by immunohistochemistry or Western blot. Tumor necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, IL-6, and IL-18 were measured using RT-PCR.


RESULTS
Mice treated with DZNeP exhibited less severe renal dysfunction and tubular injury following IR. EZH2 inhibition decreased apoptotic cells while reducing activation of caspase-3 in kidneys under IR condition. Moreover, EZH2 inhibition impaired the recruitment of CD3+ T cells and F4/80+ cells in kidneys with IR. Administration of DZNeP suppressed the production of TNF-α, MCP-1, IL-6, and IL-18 in IR-treated kidneys. Of note, EZH2 inhibition reduced p38 phosphorylation in kidneys after IR. In H/R-treated HK-2 cells, DZNeP treatment or EZH2 knockdown reduced apoptosis. EZH2 inhibition inactivated p38 resulting in reduction of active caspase-3 and proinflammatory molecules. By contrast, EZH2 overexpression induced p38 phosphorylation, caspase-3 activation, and production of proinflammatory molecules, which was reversed by SB203580.


CONCLUSIONS
EZH2 plays a crucial role in IR-induced AKI via modulation of p38 signaling. Targeting EZH2/p38 signaling pathway may offer novel strategies to protect kidneys from acute kidney injury induced by ischemia-reperfusion.
['Liang|Hua|H|http://orcid.org/0000-0003-3170-6922', 'Huang|Qiong|Q|', 'Liao|Mei-Juan|MJ|', 'Xu|Feng|F|', 'Zhang|Tao|T|', 'He|Jian|J|', 'Zhang|Lei|L|', 'Liu|Hong-Zhen|HZ|']
D058186:Acute Kidney Injury D000818:Animals D053148:Caspase 3 D002460:Cell Line D000071221:Enhancer of Zeste Homolog 2 Protein D006801:Humans D007668:Kidney D008297:Male D008810:Mice, Inbred C57BL D015427:Reperfusion Injury D015398:Signal Transduction D048051:p38 Mitogen-Activated Protein Kinases
EZH2 Apoptosis Inflammation Renal ischemia–reperfusion·p38