scholarly journals Expression of store-operated Ca2+ entry and transient receptor potential canonical and vanilloid-related proteins in rat distal pulmonary venous smooth muscle

2010 ◽  
Vol 299 (5) ◽  
pp. L621-L630 ◽  
Author(s):  
Gongyong Peng ◽  
Wenju Lu ◽  
Xiaoyan Li ◽  
Yuqin Chen ◽  
Nanshan Zhong ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Transient Receptor Potential ◽  
Pulmonary Veins ◽  
Primary Cultures ◽  
Pulmonary Arteries ◽  
Receptor Potential ◽  
Hypoxic Pulmonary Hypertension ◽  
Fura 2 ◽  
Transient Receptor

Chronic hypoxia causes remodeling and alters contractile responses in both pulmonary arteries and pulmonary veins. Although pulmonary arteries have been studied extensively in these disorders, the mechanisms by which pulmonary veins respond to hypoxia and whether these responses contribute to chronic hypoxic pulmonary hypertension remain poorly understood. In pulmonary arterial smooth muscle, we have previously demonstrated that influx of Ca2+ through store-operated calcium channels (SOCC) thought to be composed of transient receptor potential (TRP) proteins is likely to play an important role in development of chronic hypoxic pulmonary hypertension. To determine whether this mechanism could also be operative in pulmonary venous smooth muscle, we measured intracellular Ca2+ concentration ([Ca2+]i) by fura-2 fluorescence microscopy in primary cultures of pulmonary venous smooth muscle cells (PVSMC) isolated from rat distal pulmonary veins. In cells perfused with Ca2+-free media containing cyclopiazonic acid (10 μM) and nifedipine (5 μM) to deplete sarcoplasmic reticulum Ca2+ stores and block voltage-dependent Ca2+ channels, restoration of extracellular Ca2+ (2.5 mM) caused marked increases in [Ca2+]i, whereas MnCl2 (200 μM) quenched fura-2 fluorescence, indicating store-operated Ca2+ entry (SOCE). SKF-96365 and NiCl2, antagonists of SOCC, blocked SOCE at concentrations that did not alter Ca2+ responses to 60 mM KCl. Of the seven known canonical TRP (TRPC1–7) and six vanilloid-related TRP channels (TRPV1–6), real-time PCR revealed mRNA expression of TRPC1 > TRPC6 > TRPC4 > TRPC2 ≈ TRPC5 > TRPC3, TRPV2 > TRPV4 > TRPV1 in distal PVSMC, and TRPC1 > TRPC6 > TRPC3 > TRPC4 ≈ TRPC5, TRPV2 ≈ TRPV4 > TRPV1 in rat distal pulmonary vein (PV) smooth muscle. Western blotting confirmed protein expression of TRPC1, TRPC6, TRPV2, and TRPV4 in both PVSMC and PV. Our results suggest that SOCE through Ca2+ channels composed of TRP proteins may contribute to Ca2+ signaling in rat distal PV smooth muscle.

scholarly journals Bortezomib alleviates experimental pulmonary hypertension by regulating intracellular calcium homeostasis in PASMCs

2016 ◽  
Vol 311 (3) ◽  
pp. C482-C497 ◽  
Author(s):  
Jun Zhang ◽  
Wenju Lu ◽  
Yuqin Chen ◽  
Qian Jiang ◽  
Kai Yang ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Transient Receptor Potential ◽  
Hypoxia Inducible Factor ◽  
Pulmonary Arteries ◽  
Receptor Potential ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Canonical Transient Receptor Potential ◽  
Transient Receptor

The ubiquitin-proteasome system is considered to be the key regulator of protein degradation. Bortezomib (BTZ) is the first proteasome inhibitor approved by the US Food and Drug Administration for treatment of relapsed multiple myeloma and mantle cell lymphoma. Recently, BTZ treatment was reported to inhibit right ventricular hypertrophy and vascular remodeling in hypoxia-exposed and monocrotaline-injected rats. However, the underlying mechanisms remain poorly understood. We previously confirmed that hypoxia-elevated basal intracellular Ca2+ concentration ([Ca2+]i) and store-operated Ca2+ entry (SOCE) in pulmonary artery smooth muscle cells (PASMCs) are involved in pulmonary vascular remodeling. In this study we aim to determine whether BTZ attenuates the hypoxia-induced elevation of [Ca2+] in PASMCs and the signaling pathway involved in this mechanism. Our results showed that 1) in hypoxia- and monocrotaline-induced rat pulmonary hypertension (PH) models, BTZ markedly attenuated the development and progression of PH, 2) BTZ inhibited the hypoxia-induced increase in cell proliferation, basal [Ca2+]i, and SOCE in PASMCs, and 3) BTZ significantly normalized the hypoxia-upregulated expression of hypoxia-inducible factor-1α, bone morphogenetic protein 4, canonical transient receptor potential isoforms 1 and 6, and the hypoxia-downregulated expression of peroxisome proliferator-activated receptor-γ in rat distal pulmonary arteries and PASMCs. These results indicate that BTZ exerts its protective role in the development of PH potentially by inhibiting the canonical transient receptor potential-SOCE-[Ca2+]i signaling axis in PASMCs.

Capacitative calcium entry and TRPC channel proteins are expressed in rat distal pulmonary arterial smooth muscle

2004 ◽  
Vol 286 (4) ◽  
pp. L848-L858 ◽  
Author(s):  
Jian Wang ◽  
L. A. Shimoda ◽  
J. T. Sylvester
Keyword(s):  
Smooth Muscle ◽  
Transient Receptor Potential ◽  
Main Pulmonary Artery ◽  
Primary Cultures ◽  
Pulmonary Arteries ◽  
Calcium Entry ◽  
Trpc Channels ◽  
Capacitative Calcium Entry ◽  
Fura 2 ◽  
Trpc Proteins

Mammalian homologs of transient receptor potential (TRP) genes in Drosophila encode TRPC proteins, which make up cation channels that play several putative roles, including Ca2+ entry triggered by depletion of Ca2+ stores in endoplasmic reticulum (ER). This capacitative calcium entry (CCE) is thought to replenish Ca2+ stores and contribute to signaling in many tissues, including smooth muscle cells from main pulmonary artery (PASMCs); however, the roles of CCE and TRPC proteins in PASMCs from distal pulmonary arteries, which are thought to be the major site of pulmonary vasoreactivity, remain uncertain. As an initial test of the possibility that TRPC channels contribute to CCE and Ca2+ signaling in distal PASMCs, we measured [Ca2+]i by fura-2 fluorescence in primary cultures of myocytes isolated from rat intrapulmonary arteries (>4th generation). In cells perfused with Ca2+-free media containing cyclopiazonic acid (10 μM) and nifedipine (5 μM) to deplete ER Ca2+ stores and block voltage-dependent Ca2+ channels, restoration of extracellular Ca2+ (2.5 mM) caused marked increases in [Ca2+]i whereas MnCl2 (200 μM) quenched fura-2 fluorescence, indicating CCE. SKF-96365, LaCl3, and NiCl2, blocked CCE at concentrations that did not alter Ca2+ responses to 60 mM KCl (IC50 6.3, 40.4, and 191 μM, respectively). RT-PCR and Western blotting performed on RNA and protein isolated from distal intrapulmonary arteries and PASMCs revealed mRNA and protein expression for TRPC1, -4, and -6, but not TRPC2, -3, -5, or -7. Our results suggest that CCE through TRPC-encoded Ca2+ channels could contribute to Ca2+ signaling in myocytes from distal intrapulmonary arteries.

scholarly journals TRPV4 channel contributes to serotonin-induced pulmonary vasoconstriction and the enhanced vascular reactivity in chronic hypoxic pulmonary hypertension

2013 ◽  
Vol 305 (7) ◽  
pp. C704-C715 ◽  
Author(s):  
Yang Xia ◽  
Zhenzhen Fu ◽  
Jinxing Hu ◽  
Chun Huang ◽  
Omkar Paudel ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Reactivity ◽  
Transient Receptor Potential ◽  
Pulmonary Arteries ◽  
Receptor Potential ◽  
Induced Response ◽  
Transient Receptor Potential Vanilloid ◽  
Hypoxic Pulmonary Hypertension ◽  
Mechanical Coupling ◽  
Pulmonary Vasoconstriction

Transient receptor potential vanilloid 4 (TRPV4) is a mechanosensitive channel in pulmonary arterial smooth muscle cells (PASMCs). Its upregulation by chronic hypoxia is associated with enhanced myogenic tone, and genetic deletion of trpv4 suppresses the development of chronic hypoxic pulmonary hypertension (CHPH). Here we further examine the roles of TRPV4 in agonist-induced pulmonary vasoconstriction and in the enhanced vasoreactivity in CHPH. Initial evaluation of TRPV4-selective antagonists HC-067047 and RN-1734 in KCl-contracted pulmonary arteries (PAs) of trpv4−/−mice found that submicromolar HC-067047 was devoid of off-target effect on pulmonary vasoconstriction. Inhibition of TRPV4 with 0.5 μM HC-067047 significantly reduced the sensitivity of serotonin (5-HT)-induced contraction in wild-type (WT) PAs but had no effect on endothelin-1 or phenylephrine-activated response. Similar shift in the concentration-response curve of 5-HT was observed in trpv4−/−PAs, confirming specific TRPV4 contribution to 5-HT-induced vasoconstriction. 5-HT-induced Ca2+response was attenuated by HC-067047 in WT PASMCs but not in trpv4−/−PASMCs, suggesting TRPV4 is a major Ca2+pathway for 5-HT-induced Ca2+mobilization. Nifedipine also attenuated 5-HT-induced Ca2+response in WT PASMCs but did not cause further reduction in the presence of HC-067047, suggesting interdependence of TRPV4 and voltage-gated Ca2+channels in the 5-HT response. Chronic exposure (3–4 wk) of WT mice to 10% O2caused significant increase in 5-HT-induced maximal contraction, which was partially reversed by HC-067047. In concordance, the enhancement of 5-HT-induced contraction was significantly reduced in PAs of CH trpv4−/−mice and HC-067047 had no further effect on the 5-HT induced response. These results suggest unequivocally that TRPV4 contributes to 5-HT-dependent pharmaco-mechanical coupling and plays a major role in the enhanced pulmonary vasoreactivity to 5-HT in CHPH.

scholarly journals Mechanosensitivity in Pulmonary Circulation: Pathophysiological Relevance of Stretch-Activated Channels in Pulmonary Hypertension

Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1389
Author(s):  
Solène Barbeau ◽  
Guillaume Gilbert ◽  
Guillaume Cardouat ◽  
Isabelle Baudrimont ◽  
Véronique Freund-Michel ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Drug Targets ◽  
Transient Receptor Potential ◽  
Pulmonary Arteries ◽  
Receptor Potential ◽  
Cell Types ◽  
Major Step ◽  
Membrane Stretch ◽  
Transient Receptor ◽  
Stretch Activated Channels

A variety of cell types in pulmonary arteries (endothelial cells, fibroblasts, and smooth muscle cells) are continuously exposed to mechanical stimulations such as shear stress and pulsatile blood pressure, which are altered under conditions of pulmonary hypertension (PH). Most functions of such vascular cells (e.g., contraction, migration, proliferation, production of extracellular matrix proteins, etc.) depend on a key event, i.e., the increase in intracellular calcium concentration ([Ca2+]i) which results from an influx of extracellular Ca2+ and/or a release of intracellular stored Ca2+. Calcium entry from the extracellular space is a major step in the elevation of [Ca2+]i, involving a variety of plasmalemmal Ca2+ channels including the superfamily of stretch-activated channels (SAC). A common characteristic of SAC is that their gating depends on membrane stretch. In general, SAC are non-selective Ca2+-permeable cation channels, including proteins of the TRP (Transient Receptor Potential) and Piezo channel superfamily. As membrane mechano-transducers, SAC convert physical forces into biological signals and hence into a cell response. Consequently, SAC play a major role in pulmonary arterial calcium homeostasis and, thus, appear as potential novel drug targets for a better management of PH.

scholarly journals A capsaicinoid-based soft drug, AG1529, for attenuating TRPV1-mediated histaminergic and inflammatory sensory neuron excitability

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Magdalena Nikolaeva-Koleva ◽  
Laura Butron ◽  
Sara González-Rodríguez ◽  
Isabel Devesa ◽  
Pierluigi Valente ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Primary Cultures ◽  
Receptor Potential ◽  
Neuronal Firing ◽  
In Vivo Model ◽  
Drg Neurons ◽  
Trpv1 Channels ◽  
Soft Drug ◽  
Transient Receptor

AbstractTRPV1, a member of the transient receptor potential (TRP) family, is a nonselective calcium permeable ion channel gated by physical and chemical stimuli. In the skin, TRPV1 plays an important role in neurogenic inflammation, pain and pruritus associated to many dermatological diseases. Consequently, TRPV1 modulators could represent pharmacological tools to respond to important patient needs that still represent an unmet medical demand. Previously, we reported the design of capsaicinoid-based molecules that undergo dermal deactivation (soft drugs), thus preventing their long-term dermal accumulation. Here, we investigated the pharmacological properties of the lead antagonist, 2-((4-hydroxy-2-iodo-5-methoxybenzyl) amino)-2-oxoethyl dodecanoate (AG1529), on heterologously expressed human TRPV1 (hTRPV1), on nociceptor excitability and on an in vivo model of acute pruritus. We report that AG1529 competitively blocked capsaicin-evoked activation of hTRPV1 with micromolar potency, moderately affected pH-induced gating, and did not alter voltage- and heat-mediated responses. AG1529 displays modest receptor selectivity as it mildly blocked recombinant hTRPA1 and hTRPM8 channels. In primary cultures of rat dorsal root ganglion (DRG) neurons, AG1529 potently reduced capsaicin-evoked neuronal firing. AG1529 exhibited lower potency on pH-evoked TRPV1 firing, and TRPA1-elicited nociceptor excitability. Furthermore, AG1529 abolished histaminergic and inflammation mediated TRPV1 sensitization in primary cultures of DRG neurons. Noteworthy, dermal wiping of AG1529, either in an acetone-based formulation or in an anhydrous ointment, dose-dependently attenuated acute histaminergic itch in a rodent model. This cutaneous anti-pruritic effect was devoid of the normal nocifensive action evoked by the burning sensation of capsaicin. Taken together, these preclinical results unveil the mode of action of AG1529 on TRPV1 channels and substantiate the tenet that this capsaicinoid-based soft drug is a promising candidate for drug development as a topical anti-pruritic and anti-inflammatory medication.

Role of capacitative Ca2+ entry in bronchial contraction and remodeling

2002 ◽  
Vol 92 (4) ◽  
pp. 1594-1602 ◽  
Author(s):  
Michele Sweeney ◽  
Sharon S. McDaniel ◽  
Oleksandr Platoshyn ◽  
Shen Zhang ◽  
Ying Yu ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Transient Receptor Potential ◽  
Bronchial Hyperresponsiveness ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Wall Thickening ◽  
Bronchial Wall ◽  
Intracellular Ca ◽  
Transient Receptor

Asthma is characterized by airway inflammation, bronchial hyperresponsiveness, and airway obstruction by bronchospasm and bronchial wall thickening due to smooth muscle hypertrophy. A rise in cytosolic free Ca2+ concentration ([Ca2+]cyt) may serve as a shared signal transduction element that causes bronchial constriction and bronchial wall thickening in asthma. In this study, we examined whether capacitative Ca2+ entry (CCE) induced by depletion of intracellular Ca2+ stores was involved in agonist-mediated bronchial constriction and bronchial smooth muscle cell (BSMC) proliferation. In isolated bronchial rings, acetylcholine (ACh) induced a transient contraction in the absence of extracellular Ca2+ because of Ca2+ release from intracellular Ca2+ stores. Restoration of extracellular Ca2+in the presence of atropine, an M-receptor blocker, induced a further contraction that was apparently caused by a rise in [Ca2+]cyt due to CCE. In single BSMC, amplitudes of the store depletion-activated currents ( I SOC) and CCE were both enhanced when the cells proliferate, whereas chelation of extracellular Ca2+ with EGTA significantly inhibited the cell growth in the presence of serum. Furthermore, the mRNA expression of TRPC1, a transient receptor potential channel gene, was much greater in proliferating BSMC than in growth-arrested cells. Blockade of the store-operated Ca2+channels by Ni2+ decreased I SOC and CCE and markedly attenuated BSMC proliferation. These results suggest that upregulated TRPC1 expression, increased I SOC, enhanced CCE, and elevated [Ca2+]cyt may play important roles in mediating bronchial constriction and BSMC proliferation.

Acute hypoxia increases intracellular [Ca2+] in pulmonary arterial smooth muscle by enhancing capacitative Ca2+ entry

2005 ◽  
Vol 288 (6) ◽  
pp. L1059-L1069 ◽  
Author(s):  
Jian Wang ◽  
Larissa A. Shimoda ◽  
Letitia Weigand ◽  
Wenqian Wang ◽  
Dejun Sun ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Acute Hypoxia ◽  
Primary Cultures ◽  
Fluorescent Microscopy ◽  
Pulmonary Arteries ◽  
Arterial Smooth Muscle ◽  
Fura 2 ◽  
Pulmonary Arterial ◽  
Pulmonary Arterial Smooth Muscle

Hypoxic pulmonary vasoconstriction (HPV) requires influx of extracellular Ca2+ in pulmonary arterial smooth muscle cells (PASMCs). To determine whether capacitative Ca2+ entry (CCE) through store-operated Ca2+ channels (SOCCs) contributes to this influx, we used fluorescent microscopy and the Ca2+-sensitive dye fura-2 to measure effects of 4% O2 on intracellular [Ca2+] ([Ca2+]i) and CCE in primary cultures of PASMCs from rat distal pulmonary arteries. In PASMCs perfused with Ca2+-free Krebs Ringer bicarbonate solution (KRBS) containing cyclopiazonic acid to deplete Ca2+ stores in sarcoplasmic reticulum and nifedipine to prevent Ca2+ entry through L-type voltage-operated Ca2+ channels (VOCCs), hypoxia markedly enhanced both the increase in [Ca2+]i caused by restoration of extracellular [Ca2+] and the rate at which extracellular Mn2+ quenched fura-2 fluorescence. These effects, as well as the increased [Ca2+]i caused by hypoxia in PASMCs perfused with normal salt solutions, were blocked by the SOCC antagonists SKF-96365, NiCl2, and LaCl3 at concentrations that inhibited CCE >80% but did not alter [Ca2+]i responses to 60 mM KCl. In contrast, the VOCC antagonist nifedipine inhibited [Ca2+]i responses to hypoxia by only 50% at concentrations that completely blocked responses to KCl. The increased [Ca2+]i caused by hypoxia was completely reversed by perfusion with Ca2+-free KRBS. LaCl3 increased basal [Ca2+]i during normoxia, indicating effects other than inhibition of SOCCs. Our results suggest that acute hypoxia enhances CCE through SOCCs in distal PASMCs, leading to depolarization, secondary activation of VOCCs, and increased [Ca2+]i. SOCCs and CCE may play important roles in HPV.

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