Expression of olfactory-type cyclic nucleotide-gated channel (CNGA2) in vascular tissues.
Cyclic nucleotide-gated (CNG) ion channels are Ca2+-permeable nonselective cation channels that are directly gated by the binding of cAMP or cGMP. Previous studies have identified the expression of CNGA1 channels in vascular endothelial cells. The opening of CNG channels is expected to result in a rise in endothelial cytosolic Ca2+, which may trigger multiple physiological changes. In the present study, we extensively studied the expression pattern of the functional subunit of olfactory-type CNG channels (CNGA2) in vascular tissues. Northern blot analysis detected a transcript of approximately 2.6 kb in mRNA isolated from rat aorta. RT-PCR amplified a 582-bp CNGA2 fragment from RNA samples isolated from rat aorta, bovine endothelia cell CCL-209, and rat smooth muscle cell A7r5. Furthermore, in situ hybridization and immunohistochemistry revealed that CNGA2 mRNA and proteins were expressed in the endothelium and smooth muscle layers of human coronary and cerebral arteries. In conclusion, our study indicates that CNGA2 channels are widely expressed in vascular tissues across different species. These results suggest a potential ubiquitous role of CNGA2 channels in mediating Ca2+ influx in vascular cells.
Cheng
Kwong-Tai
KT
Department of Physiology, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
Chan
Franky Leung
FL
Huang
Yu
Y
Chan
Wing-Yee
WY
Yao
Xiaoqiang
X
D000818:Animals; D015152:Blotting, Northern; D002417:Cattle; D002460:Cell Line; D054815:Cyclic Nucleotide-Gated Cation Channels; D004730:Endothelium, Vascular / Q000378:metabolism*; D006801:Humans; D017403:In Situ Hybridization; D007473:Ion Channels / Q000096:biosynthesis* / Q000235:genetics; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D011651:Pulmonary Artery / Q000166:cytology; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction
D054815:Cyclic Nucleotide-Gated Cation Channels; D007473:Ion Channels