Post-transcriptional silencing of TRPC1 ion channel gene by RNA interference upregulates TRPC6 expression and store-operated Ca2+ entry in A7r5 vascular smooth muscle cells.
This study investigates functional consequences of TRPC1 ion channel downregulation observed in aging rat aorta by employing RNA interference in cultured vascular smooth muscle cells. For this purpose, A7r5 aortic smooth muscle cells were used in quantitative gene and protein expression as well as in functional analyses. According to quantitative RT-PCR results, TRPC3, TRPC4 and TRPC5 mRNAs were not at detectable levels. In siTRPC1-transfected cells, TRPC1 mRNA and protein levels were decreased by 40% and 64%; however, those of TRPC6 were drastically increased by 100% and 200%, respectively. In fura-2-loaded TRPC1 knockdown cells, despite the decreased TRPC1 levels, cyclopiazonic acid-induced Ca2+ entry and store-operated Ca2+ entry following Ca2+ addition were elevated by 77% and 135%, respectively. Results suggest that decrease in TRPC1 may be compensated by upregulated TRPC6 that possibly takes part in store-operated Ca2+ entry in vascular smooth muscle cells.
Selli
Cigdem
C
Department of Pharmacology, Faculty of Pharmacy, Ege University, 35100, Izmir, Turkey.
Erac
Yasemin
Y
Kosova
Buket
B
Tosun
Metiner
M
D000818:Animals; D001013:Aorta, Thoracic / Q000196:embryology; D001921:Brain / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002460:Cell Line; D055785:Gene Knockdown Techniques; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D009928:Organ Specificity; D053499:Plasma Membrane Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019831:Sodium-Calcium Exchanger / Q000037:antagonists & inhibitors; D050052:TRPC Cation Channels / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
D020033:Protein Isoforms; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D019831:Sodium-Calcium Exchanger; D050052:TRPC Cation Channels; C492145:Trpc6 protein, rat; C096351:transient receptor potential cation channel, subfamily C, member 1; D053499:Plasma Membrane Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D002118:Calcium