Caveolin-1 Assembles Type 1 Inositol 1,4,5-Trisphosphate Receptors and Canonical Transient Receptor Potential 3 Channels into a Functional Signaling Complex in Arterial Smooth Muscle Cells

In pulmonary arterial smooth muscle cells (PASMCs), Ca2+ influx through store-operated Ca2+ channels thought to be composed of canonical transient receptor potential (TRPC) proteins is an important determinant of intracellular free calcium concentration ([Ca2+]i) and pulmonary vascular tone. Sildenafil, a type V phosphodiesterase inhibitor that increases cellular cGMP, is recently identified as a promising agent for treatment of pulmonary hypertension. We previously demonstrated that chronic hypoxia elevated basal [Ca2+]i in PASMCs due in large part to enhanced store-operated Ca2+ entry (SOCE); moreover, ex vivo exposure to prolonged hypoxia (4% O2 for 60 h) upregulated TRPC1 and TRPC6 expression in PASMCs. We examined the effect of sildenafil on basal [Ca2+]i, SOCE, and the expression of TRPC in PASMCs under prolonged hypoxia exposure. We also examined the effect of sildenafil on TRPC1 and TRPC6 expression in pulmonary arterial smooth muscle (PA) from rats that developed chronically hypoxic pulmonary hypertension (CHPH). Compared with vehicle control, treatment with sildenafil (300 nM) inhibited prolonged hypoxia induced increases of 1) basal [Ca2+]i, 2) SOCE, and 3) mRNA and protein expression of TRPC in PASMCs. Moreover, sildenafil (50 mg · kg−1 · day−1) inhibited mRNA and protein expression of TRPC1 and TRPC6 in PA from chronically hypoxic (10% O2 for 21 days) rats, which was associated with decreased right ventricular pressure and right ventricular hypertrophy. Furthermore, we found, in PASMCs exposed to prolonged hypoxia, that knockdown of TRPC1 or TRPC6 by their specific small interference RNA attenuated the hypoxic increases of SOCE and basal [Ca2+]i, suggesting a cause and effect link between increases of TRPC1 and TRPC6 expression and the hypoxic increases of SOCE and basal [Ca2+]i. These results suggest that sildenafil may alter basal [Ca2+]i in PASMCs by decreasing SOCE through downregulation of TRPC1 and TRPC6 expression, thereby contributing to decreased vascular tone of pulmonary arteries during the development of CHPH.

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Bone morphogenetic protein 4 enhances canonical transient receptor potential expression, store-operated Ca2+ entry, and basal [Ca2+]i in rat distal pulmonary arterial smooth muscle cells

AJP Cell Physiology ◽

10.1152/ajpcell.00040.2010 ◽

2010 ◽

Vol 299 (6) ◽

pp. C1370-C1378 ◽

Cited By ~ 23

Author(s):

Wenju Lu ◽

Pixin Ran ◽

Dandan Zhang ◽

Ning Lai ◽

Nanshan Zhong ◽

...

Keyword(s):

Transient Receptor Potential ◽

Receptor Potential ◽

Pulmonary Vascular Remodeling ◽

Canonical Transient Receptor Potential ◽

Morphogenetic Protein ◽

Mrna And Protein Expression ◽

Pulmonary Arterial ◽

Arterial Smooth Muscle Cells ◽

Pulmonary Arterial Smooth Muscle ◽

Transient Receptor

Recent advances have identified an important role of bone morphogenetic protein 4 (BMP4) in pulmonary vascular remodeling, yet the underlying mechanisms remain largely unexplored. We have previously found that Ca2+ influx through store-operated calcium channels (SOCC), which are mainly thought to be composed of canonical transient receptor potential (TRPC) proteins, likely contribute to the pathogenic development of chronic hypoxic pulmonary hypertension. In this study, we investigated the effect of BMP4 on expression of TRPC and store-operated Ca2+ entry (SOCE) in pulmonary arterial smooth muscle cells (PASMCs). Real-time quantitative PCR and Western blotting revealed that treatment with BMP4 (50 ng/ml, 60 h) increased TRPC1, TRPC4, and TRPC6 mRNA and protein expression in growth-arrested rat distal PASMCs. Moreover, in comparison to vehicle control, cells treated with BMP4 also exhibited enhanced SOCE, and elevated basal intracellular calcium concentration ([Ca2+]i) as determined by fluorescent microscopy using the Ca2+ indicator Fura-2 AM. Perfusing cells with Ca2+-free Krebs-Ringer bicarbonate solution (KRBS) or KRBS containing SOCC antagonists SKF-96365 or NiCl2 attenuated the increases in basal [Ca2+]i caused by BMP4. Specific knockdown of BMP4 by small interference RNA significantly decreased the mRNA and protein expression of TRPC1, TRPC4, and TRPC6 and reduced SOCE and basal [Ca2+]i in serum-stimulated PASMCs. We conclude that BMP4 regulates calcium signaling in PASMCs likely via upregulation of TRPC expression, leading to enhanced SOCE and basal [Ca2+]i in PASMCs, and by this mechanism contributes to pulmonary vascular remodeling during pulmonary arterial hypertension.

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Attenuation of Canonical Transient Receptor Potential-Like Channel 6 Expression Specifically Reduces the Diacylglycerol-Mediated Increase in Intracellular Calcium in Human Myometrial Cells

Endocrinology ◽

10.1210/en.2009-0085 ◽

2010 ◽

Vol 151 (1) ◽

pp. 406-416 ◽

Cited By ~ 11

Author(s):

Daesuk Chung ◽

Yoon-Sun Kim ◽

Jennifer N. Phillips ◽

Aida Ulloa ◽

Chun-Ying Ku ◽

...

Keyword(s):

Smooth Muscle ◽

Transient Receptor Potential ◽

Contractile Activity ◽

Receptor Potential ◽

Myometrial Cells ◽

Canonical Transient Receptor Potential ◽

Voltage Dependent ◽

Transient Receptor ◽

Entry Mechanism

Abstract An increase in intracellular Ca2+ ([Ca2+]i) as a result of release of Ca2+ from intracellular stores or influx of extracellular Ca2+ contributes to the regulation of smooth muscle contractile activity. Human uterine smooth muscle cells exhibit receptor-, store-, and diacylglycerol (OAG)-mediated extracellular Ca2+-dependent increases in [Ca2+]i (SRCE) and express canonical transient receptor potential-like channels (TRPC) mRNAs (predominantly TRPC1, -4, and -6) that have been implicated in SRCE. To determine the role of TRPC6 in human myometrial SRCE, short hairpin RNA constructs were designed that effectively targeted a TRPC6 mRNA reporter for degradation. One sequence was used to produce an adenovirus construct (TC6sh1). TC6sh1 reduced TRPC6 mRNA but not TRPC1, -3, -4, -5, or -7 mRNAs in PHM1-41 myometrial cells. Compared with uninfected cells or cells infected with empty vector, the increase in [Ca2+]i in response to OAG was specifically inhibited by TC6sh1, whereas SRCE responses elicited by either oxytocin or thapsigargin were not changed. Similar findings were observed in primary pregnant human myometrial cells. When PHM1-41 cells were activated by OAG in the absence of extracellular Na+, the increase in [Ca2+]i was partially reduced. Furthermore, pretreatment with nifedipine, an L-type calcium channel blocker, also partially reduced the OAG-induced [Ca2+]i increase. Similar effects were observed in primary human myometrial cells. These findings suggest that OAG activates channels containing TRPC6 in myometrial cells and that these channels act via both enhanced Na+ entry coupled to activation of voltage-dependent Ca2+ entry channels and a nifedipine-independent Ca2+ entry mechanism to promote elevation of intracellular Ca2+.

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Canonical Transient Receptor Potential Channels and Vascular Smooth Muscle Cell Plasticity

Journal of Lipid and Atherosclerosis ◽

10.12997/jla.2020.9.1.124 ◽

2020 ◽

Vol 9 (1) ◽

pp. 124

Author(s):

Motohiro Nishida ◽

Tomohiro Tanaka ◽

Supachoke Mangmool ◽

Kazuhiro Nishiyama ◽

Akiyuki Nishimura

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cell ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Transient Receptor Potential Channels ◽

Cell Plasticity ◽

Canonical Transient Receptor Potential ◽

Potential Channels ◽

Transient Receptor

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TRPC3 mediates pyrimidine receptor-induced depolarization of cerebral arteries

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00861.2004 ◽

2005 ◽

Vol 288 (5) ◽

pp. H2055-H2061 ◽

Cited By ~ 115

Author(s):

S. A. Reading ◽

S. Earley ◽

B. J. Waldron ◽

D. G. Welsh ◽

J. E. Brayden

Keyword(s):

Transient Receptor Potential ◽

Cerebral Arteries ◽

Receptor Potential ◽

Receptor Activation ◽

Antisense Oligodeoxynucleotides ◽

Canonical Transient Receptor Potential ◽

Cell Current ◽

Arterial Smooth Muscle Cells ◽

Transient Receptor ◽

Intravascular Pressure

We tested the hypothesis that TRPC3, a member of the canonical transient receptor potential (TRP) family of channels, mediates agonist-induced depolarization of arterial smooth muscle cells (SMCs). In support of this hypothesis, we observed that suppression of arterial SMC TRPC3 expression with antisense oligodeoxynucleotides significantly decreased the depolarization and constriction of intact cerebral arteries in response to UTP. In contrast, depolarization and contraction of SMCs induced by increased intravascular pressure, i.e., myogenic responses, were not altered by TRPC3 suppression. Interestingly, UTP-evoked responses were not affected by suppression of a related TRP channel, TRPC6, which was previously found to be involved in myogenic depolarization and vasoconstriction. In patch-clamp experiments, UTP activated a whole cell current that was greatly reduced or absent in TRPC3 antisense-treated SMCs. These results indicate that TRPC3 mediates UTP-induced depolarization of arterial SMCs and that TRPC3 and TRPC6 may be differentially regulated by receptor activation and mechanical stimulation, respectively.

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