BIRC5 is a novel target of peroxisome proliferator-activated receptor γ in brain microvascular endothelium cells during cerebral ischemia

Cerebral ischemia is a leading cause of ischemic stroke, which may lead to severe disability and mortality worldwide. There are some key factors concerned in cardioprotection, such as peroxisome proliferator‑activated receptor γ (PPARγ), a ligand binding transcription factor involved in various biological functions including atherosclerosis, vascular dysfunction and hypertension, and baculoviral IAP repeat‑containing 5 (BIRC5), which may protect human brain endothelial cells from ischemia‑induced apoptosis. To determine the potential roles of PPARγ in brain microvascular endothelial (bEnd.3) cells during cerebral ischemia and the relationship between PPARγ and BIRC5, a cerebral ischemia model was established with bEnd.3 cells cells by oxygen‑glucose deprivation (OGD) treatment. OGD treatment reduced proliferation and enhanced apoptosis of bEnd.3 cells in a time‑dependent manner. PPARγ expression levels were decreased in bEnd.3 cells following OGD treatment. Upregulation of PPARγ expression protected bEnd.3 cells from ischemia injury and also upregulated BIRC5 expression. PPARγ‑specific binding sites in the BIRC5 promoter were predicted bioinformatically and verified by luciferase reporter experiments. Results from electrophoretic mobility shift/supershift and chromatin immunoprecipitation assays suggested that BIRC5 may be a novel target of PPARγ transcriptional regulation during ischemic injury. The present results indicated that PPARγ may serve a protective role on bEnd.3 cells and that BIRC5 may be a downstream target of PPARγ regulation during cerebral ischemia.