Cholesterol modulates function of connexin 43 gap junction channel via PKC pathway in H9c2 cells.
It has been shown that cholesterol modulates activity of protein kinase C (PKC), and PKC phosphorylates connexin 43 (Cx43) to regulate its function, respectively. However, it is not known whether cholesterol modulates function of Cx43 through regulating activity of PKC. In the present study, we demonstrated that cholesterol enrichment reduced the dye transfer ability of Cx43 in cultured H9c2 cells. Western blot analysis indicated that cholesterol enrichment enhanced the phosphorylated state of Cx43. Immunofluorescent images showed that cholesterol enrichment made the Cx43 distribution from condensed to diffused manner in the interface between the cells. In cholesterol enriched cells, PKC antagonists partially restored the dye transfer ability among the cells, downregulated the phosphorylation of Cx43 and redistributed Cx43 from the diffused manner to the condensed manner in the cell interface. In addition, reduction of cholesterol level suppressed PKC activity to phosphorylate Cx43 and restored Cx43 function in PKC agonist-treated cells. Furthermore, we demonstrated that cholesterol enrichment upregulated the phosphorylated state of Cx43 at Ser368, while PKC antagonists reversed the effect. Taken together, cholesterol level in the cells plays important roles in regulating Cx43 function through activation of the PKC signaling pathway.
Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China. Electronic address: zoujun@xmu.edu.cn.
Jun
J
Zou
Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China.
Xiao-Yang
XY
Yue
Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China.
Sheng-Chao
SC
Zheng
Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China; Xiamen Heart Center, Zhongshan Hospital affiliated to Xiamen University, Xiamen 361004, China.
Guangwei
G
Zhang
Xiamen Heart Center, Zhongshan Hospital affiliated to Xiamen University, Xiamen 361004, China.
He
H
Chang
Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China.
Yan-Chun
YC
Liao
Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China.
Ye
Y
Zhang
Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China.
Mao-Qiang
MQ
Xue
Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China. Electronic address: qizhi@xmu.edu.cn.
Zhi
Z
Qi
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002450:Cell Communication / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002784:Cholesterol / Q000494:pharmacology*; D018031:Connexin 43 / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D017629:Gap Junctions / Q000187:drug effects*; D006321:Heart / Q000187:drug effects*; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects*
D018031:Connexin 43; D004791:Enzyme Inhibitors; D002784:Cholesterol; D011493:Protein Kinase C
Cholesterol depletion; Cholesterol enrichment; Cx43 phosphorylation; Dye transfer; Protein kinase C