TRIM37 exacerbates cerebral ischemic injury by regulating the PPARγ/NF-κB pathway

Abstract

Ischemic stroke is the primary cause of mortality for individuals with disability worldwide. Tripartite motif 37 (TRIM37) plays multiple regulatory roles in various cellular processes. Our research aimed to investigate the effects of TRIM37 on the progression of ischemic stroke and its related mechanisms. Primary rat brain microvascular endothelial cells (BMECs) were treated with oxygen-glucose deprivation and reoxygenation (OGD/R) and then transduced with pShuttle-H1-TRIM37 shRNA plasmid, pShuttle-CMV-TRIM37 plasmid, or corresponding negative controls. The effects of TRIM37 were also explored in middle cerebral artery occlusion surgery-induced rat brain damage in vivo. Factor VIII staining showed the successful isolation of the primary BMECs. The OGD/R procedure significantly inhibited the cell viability and upregulated the TRIM37 expression in a time-dependent manner. In addition, OGD/R evidently increased the cell permeability, elevated the tumor necrosis factor alpha and intercellular adhesion molecule 1 levels, and upregulated the nuclear expression of nuclear factor (NF)-κB, but downregulated the peroxisome proliferator-activated receptors γ (PPARγ), zonula occludens-1, and cytoplasmic NF-κB expressions, which were reversed by TRIM37 knockdown. Furthermore, TRIM37 interacted with PPARγ and promoted its ubiquitination. The effects on cell permeability and inflammation induced by TRIM37 overexpression were reversed by PPARγ agonist. TRIM37 knockdown also inhibited middle cerebral artery occlusion-induced rat brain damage in vitro. TRIM37 may be a potential therapeutic target for ischemic stroke, and the knockdown of TRIM37 may improve brain injury by regulating the PPARγ/NF-κB pathway to modulate the inflammatory response.