Increase in caveolae and caveolin-1 expression modulates agonist-induced contraction and store- and receptor-operated Ca2+ entry in pulmonary arteries of pulmonary hypertensive rats

Increased caveolin‐1 expression enhances the receptor‐operated Ca2+ entry in the aorta of two‐kidney, one‐clip hypertensive rats

“…Different types of arteries respond differently to agonists, and the dissimilarities might be attributable to multiple mechanisms of calcium regulation. From our previous studies, we have verified that upregulated Cav1 in pulmonary arteries is strongly associated with SOCCs and ROCCs in a rat model of pulmonary hypertension, but Cav1 in the aorta of these rats is only related to ROCCs (Jiao et al., ; Mu et al ., ). Therefore, we hypothesized that Cav1 might execute different regulatory mechanisms in calcium channels of different types of arteries.…”

“…Endothelin‐1 can activate receptor‐operated Ca 2+ entry (ROCE) by activating phospholipase C expression to produce diacylglycerol (Kato et al., ), which subsequently stimulates the depletion of Ca 2+ stores in the sarcoplasmic reticulum, leading to activation of store‐operated Ca 2+ entry (SOCE) (Xu, Elimban, & Dhalla, ). Previous studies have suggested that ET‐1‐induced pulmonary arterial contraction is increased in pulmonary hypertension (Jiao et al., ; Liu et al., ; Wang et al., ). In our previous research, we destroyed caveolar structure with MβCD and found that the ET‐1‐induced aortic contraction was dramatically reduced, but the inhibition was not significantly different between the control and pulmonary hypertension groups (Mu et al., ).…”

“…The Trpc6 channel localizes at the caveolar microdomains and can be inhibited by the disruption of caveolae (Lei et al., ). Our previous research has found that Cav1 is strongly associated with SOCCs and ROCCs in pulmonary arteries from a rat model of pulmonary hypertension, and that the regulation of Cav1 in Ca 2+ channels is also observed in the aorta of these rats, even though the expression of Cav1 is not statistically different when compared with that of the control group (Jiao et al., ; Mu et al., ). Thus, Cav1 and its role in regulating calcium channels in VSMCs currently serves as a candidate for investigations into hypertension.…”

“…The alteration of [Ca 2+ ] i was monitored using the membrane‐permeable Ca 2+ ‐sensitive fluorescent dye fluo‐3 AM (Jiao et al., ; Mu et al ., ). Aortic smooth muscle cells were loaded with 5 μ m fluo‐3 AM at room temperature (22–24°C) for 30 min.…”

“…Total protein was extracted from the aorta or third‐order branchess of the mesenteric artery without endothelium. Protein samples (20 μg) were separated by standard SDS‐PAGE and electrophoretically transferred to polyvinylidene difluoride membranes (Jiao et al., ; Mu et al., ). The membranes were incubated with polyclonal rabbit anti‐Cav1 (1:5000; 3238, Cell Signaling Technology, Danvers, MA, USA), anti‐Trpc1 (1:300; sc‐133076, Santa Cruz Biotechnology, Heidelberg, Germany), anti‐Trpc6 (1:300; ab63038, Abcam, Cambridge, UK) or anti‐β‐Actin (1:5000; 8H10D10, Cell Signaling Technology) antibodies at 4°C overnight.…”