Abstract
Hypoxia-inducible factor 1 (HIF-1) is a master regulator of cellular adaptation to hypoxia and has been suggested as a
potent therapeutic target in cerebral ischemia. Here we show in an ischemic stroke model of rats that inhibiting HIF-1 and
its downstream genes by 3-(5’-hydroxymethyl-2’-furyl)-1-benzylindazole (YC-1) significantly increases mortality and enlarges
infarct volume evaluated by MRI and histological staining. Interestingly, the HIF-1 inhibition remarkably ameliorates
ischemia-induced blood-brain barrier (BBB) disruption determined by Evans blue leakage although it does not affect brain
edema. The result demonstrates that HIF-1 inhibition has differential effects on ischemic outcomes and BBB permeability. It
indicates that HIF-1 may have different functions in different brain cells. Further analyses show that ischemia upregulates
HIF-1 and its downstream genes erythropoietin (EPO), vascular endothelial growth factor (VEGF), and glucose transporter
(Glut) in neurons and brain endothelial cells and that YC-1 inhibits their expression. We postulate that HIF-1-induced VEGF
increases BBB permeability while certain other proteins coded by HIF-1’s downstream genes such as epo and glut provide
neuroprotection in an ischemic brain. The results indicate that YC-1 lacks the potential as a cerebral ischemic treatment
although it confers certain protection to the cerebral vascular system.
Description
This is the publisher's version, also available from http://dx.doi.org/10.1371/journal.pone.0027798.