Peroxisome proliferator-activated receptor gamma agonist rosiglitazone attenuates oxyhemoglobin-induced Toll-like receptor 4 expression in vascular smooth muscle cells.
Inflammation and immune response have been implicated in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). Recently, increased TLR4 expression has been associated with the development of cerebral vasospasm in a rabbit model of SAH. Peroxisome proliferator-activated receptor gamma (PPARgamma) agonists, effective inhibitors of TLR4 activation, may modulate the vasospasm progression via their anti-inflammation effects. We investigate whether the blood component oxyhemoglobin (OxyHb) can induce the expression of Toll-like receptor (TLR) 4 in vascular smooth muscle cells (VSMCs), and evaluate the modulatory effects of PPARgamma agonist rosiglitazone on OxyHb-induced inflammation in VSMCs. Cultured VSMCs incubated with or without rosiglitazone were exposed to OxyHb at 10muM for up to 48h. Expression of TLR4 was assessed by immunocytochemistry and Western blot analysis. Production of tumor necrosis factor alpha (TNF-alpha) in conditioned medium were quantified by ELISA. A marked increase of TLR4 production and TNF-alpha release was observed at 48h after cells were treated with OxyHb. Rosiglitazone reduced TLR4 immunocytochemistry staining and protein production significantly in VSMCs. A specific antagonist for PPARgamma, GW9662, could reverse the anti-inflammatory effects of rosiglitazone. The results demonstrated that OxyHb exposure could induce TLR4 activation in cultured VSMCs. Rosiglitazone suppressed TLR4 expression and cytokine release via the activation of PPARgamma and may have a therapeutic potential for the treatment of vasospasm following SAH.
Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province, China.
Yi
Y
Wu
Xu-Dong
XD
Zhao
Zong
Z
Zhuang
Ya-Jun
YJ
Xue
Hui-Lin
HL
Cheng
Hong-Xia
HX
Yin
Ji-Xin
JX
Shi
D000813:Anilides / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D007249:Inflammation / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism; D010108:Oxyhemoglobins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D047495:PPAR gamma / Q000819:agonists* / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077154:Rosiglitazone; D013345:Subarachnoid Hemorrhage / Q000150:complications; D045162:Thiazolidinediones / Q000494:pharmacology*; D051197:Toll-Like Receptor 4 / Q000187:drug effects* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014665:Vasodilator Agents / Q000494:pharmacology; D020301:Vasospasm, Intracranial / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology
C457499:2-chloro-5-nitrobenzanilide; D000813:Anilides; D017077:Culture Media, Conditioned; D010108:Oxyhemoglobins; D047495:PPAR gamma; D045162:Thiazolidinediones; C495347:Tlr4 protein, rat; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D014665:Vasodilator Agents; D000077154:Rosiglitazone