Blockade of connexin 43 hemichannels reduces neointima formation after vascular injury by inhibiting proliferation and phenotypic modulation of smooth muscle cells.
Connexins 43 (Cx43) plays a key role in neointimal formation after vascular injury, but the mechanism still needs to be further explored. We hypothesized that the gap junction-dependent function of Cx43 to mediate intercellular communication has a crucial role in the development and progression of vascular diseases. The effect of intercellular communication mediated by Cx43 hemichannels on neointimal formation after vascular injury was investigated. Cx43 was overexpressed or knockdown in rat vascular smooth muscle cell (SMC) by transfection pcDNA-Cx43 plasmid or small interfering RNA (siRNA) against Cx43 (siCx43). SMC proliferation and marker genes expression after Cx43 alteration and blockade of the Cx43 hemichannel were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay and RT-PCR. The effect of carbenoxolone on neointimal formation was investigated in carotid artery injured rat model. We demonstrated that overexpression of Cx43 promoted SMC proliferation, meanwhile, mRNA expression level of smooth muscle alpha-actin and calponin, which were important markers of SMC in a contractile state, were down-regulated in smooth muscle. Knockdown of Cx43 inhibited SMC proliferation but increased SMC marker genes expression level. Carbenoxolone (50 muM) improved SMC contractile differentiation and inhibited its proliferation. Our data showed that carbenoxolone reduced neointimal formation after carotid artery injury. In summary, blockade of intercellular communication via Cx43 hemichannels reduces neointimal formation after vascular injury by inhibiting proliferation and phenotypic modulation of SMCs.
Song
MingBao
M
Institute of Cardiovascular Diseases of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, People's Republic of China.
Yu
XueJun
X
Cui
Xin
X
Zhu
GuangXu
G
Zhao
Gang
G
Chen
JianFei
J
Huang
Lan
L
D000818:Animals; D002229:Carbenoxolone / Q000494:pharmacology; D020212:Carotid Artery Injuries / Q000378:metabolism*; D049109:Cell Proliferation / Q000187:drug effects; D004396:Coloring Agents / Q000378:metabolism; D018031:Connexin 43 / Q000235:genetics / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism; D036681:Fluorescence Recovery After Photobleaching; D019084:Fluorescent Antibody Technique, Indirect; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism; D014162:Transfection; D017539:Tunica Intima / Q000187:drug effects / Q000378:metabolism*
D004396:Coloring Agents; D018031:Connexin 43; C514423:Gap 26 peptide; D010455:Peptides; D034741:RNA, Small Interfering; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue; D002229:Carbenoxolone