Sequential opening of IP3-sensitive Ca2+channels and SOC during α-adrenergic activation of rabbit vena cava

2002 ◽  
Vol 282 (5) ◽  
pp. H1768-H1777 ◽  
Author(s):  
Cheng-Han Lee ◽  
Roshanak Rahimian ◽  
Tania Szado ◽  
Jasmin Sandhu ◽  
Damon Poburko ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Transient Receptor Potential ◽  
Vena Cava ◽  
Receptor Potential ◽  
Selective Inhibition ◽  
Pcr Analysis ◽  
Release Channel ◽  
Plasmic Reticulum ◽  
Intracellular Ca ◽  
Transient Receptor

α1-Aderenoceptor-mediated constriction of rabbit inferior vena cava (IVC) is signaled by asynchronous wavelike Ca2+ oscillations in the in situ smooth muscle. We have shown previously that a putative nonselective cationic channel (NSCC) is required for these oscillations. In this report, we show that the application of 2-aminoethoxyphenyl borate (2-APB) to antagonize inositol 1,4,5-trisphosphate (InsP3)-sensitive Ca2+ release channels (IP3R channels) can prevent the initiation and abolish ongoing α1-aderenoceptor-mediated tonic constriction of the venous smooth muscle by inhibiting the generation of these intracellular Ca2+ concentration ([Ca2+]i) oscillations. The observed effects of 2-APB can only be attributed to its selective inhibition on the IP3R channels, not to its slight inhibition of the L-type voltage-gated Ca2+ channel and the sarco(endo)plasmic reticulum Ca2+ ATPase. Furthermore, 2-APB had no effect on the ryanodine-sensitive Ca2+ release channel and the store-operated channel (SOC) in the IVC. These results indicate that the putative NSCC involved in refilling the sarcoplasmic reticulum (SR) and maintaining the tonic contraction is most likely an SOC-type channel because it appears to be activated by IP3R-channel-mediated SR Ca2+ release or store depletion. This is in accordance with its sensitivity to Ni2+ and La3+ (SOC blockers). More interestingly, RT-PCR analysis indicates that transient receptor potential (Trp1) mRNA is strongly expressed in the rabbit IVC. The Trp1 gene is known to encode a component of the store-operated NSCC. These new data suggest that the activation of both the IP3R channels and the SOC are required for PE-mediated [Ca2+]i oscillations and constriction of the rabbit IVC.

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.

Mibefradil suppresses the proliferation of pulmonary artery smooth muscle cells

2016 ◽  
Vol 64 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Hong-Hong Li ◽  
Li-Jian Xie ◽  
Ting-Ting Xiao ◽  
Min Huang ◽  
Jie Shen
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Transient Receptor Potential ◽  
Critical Role ◽  
Receptor Potential ◽  
Channel Expression ◽  
Intracellular Ca ◽  
Pulmonary Arterial ◽  
Pulmonary Artery Smooth Muscle ◽  
Transient Receptor

Intracellular Ca2+ levels play a critical role in the regulation of vasodilation and vasoconstriction by stimulating pulmonary artery smooth muscle cell (PASMC) proliferation, which is important in the pathogenesis of pulmonary arterial hypertension (PAH); however, L-type Ca2+ channel antagonists are useful in only few patients with PAH. The present study sought to assess the effect of mibefradil, which blocks T-type Ca2+ channels, on PASMC proliferation and Ca2+ channel profile. Human PASMCs were stimulated with 25 ng/mL platelet-derived growth factor-BB (PDGF-BB) with and without 10 µM mibefradil or 100 nM sildenafil. After 48 or 72 h, PASMC proliferation and Ca2+ channel expression were assessed by MTT assays and western blot analysis, respectively. PDGF-BB-induced PASMC proliferation at 72 h (p<0.01), which was inhibited by both sildenafil and mibefradil (p<0.01). Transient receptor potential Ca2+ channel 6 (TRPC6) expression was significantly increased with PDGF-BB stimulation (p=0.009); however, no changes in TRPC1, TRPC3, CAV1.2, and CAV3.2 levels were observed. Although both TRPC1 and CAV1.2 expression levels were increased in PDGF-stimulated PASMCs on mibefradil and sildenafil treatment, it was not statistically significant (p=0.086 and 1.000, respectively). Mibefradil inhibits PDGF-BB-stimulated PASMC proliferation; however, the mechanism through which it functions remains to be determined. Further studies are required to elucidate the full therapeutic value of mibefradil for PAH.

scholarly journals Ca2+ handling is altered when arterial myocytes progress from a contractile to a proliferative phenotype in culture

2008 ◽  
Vol 295 (3) ◽  
pp. C779-C790 ◽  
Author(s):  
Roberto Berra-Romani ◽  
Amparo Mazzocco-Spezzia ◽  
Maria V. Pulina ◽  
Vera A. Golovina
Keyword(s):  
Transient Receptor Potential ◽  
Critical Role ◽  
Cyclopiazonic Acid ◽  
Receptor Potential ◽  
Proliferating Cells ◽  
Functional Changes ◽  
Plasmic Reticulum ◽  
Rat Mesenteric Artery ◽  
Intracellular Ca ◽  
Transient Receptor

Phenotypic modulation of vascular myocytes is important for vascular development and adaptation. A characteristic feature of this process is alteration in intracellular Ca2+ handling, which is not completely understood. We studied mechanisms involved in functional changes of inositol 1,4,5-trisphosphate (IP3)- and ryanodine (Ry)-sensitive Ca2+ stores, store-operated Ca2+ entry (SOCE), and receptor-operated Ca2+ entry (ROCE) associated with arterial myocyte modulation from a contractile to a proliferative phenotype in culture. Proliferating, cultured myocytes from rat mesenteric artery have elevated resting cytosolic Ca2+ levels and increased IP3-sensitive Ca2+ store content. ATP- and cyclopiazonic acid [CPA; a sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) inhibitor]-induced Ca2+ transients in Ca2+-free medium are significantly larger in proliferating arterial smooth muscle cells (ASMCs) than in freshly dissociated myocytes, whereas caffeine (Caf)-induced Ca2+ release is much smaller. Moreover, the Caf/Ry-sensitive store gradually loses sensitivity to Caf activation during cell culture. These changes can be explained by increased expression of all three IP3 receptors and a switch from Ry receptor type II to type III expression during proliferation. SOCE, activated by depletion of the IP3/CPA-sensitive store, is greatly increased in proliferating ASMCs. Augmented SOCE and ROCE (activated by the diacylglycerol analog 1-oleoyl-2-acetyl- sn-glycerol) in proliferating myocytes can be attributed to upregulated expression of, respectively, transient receptor potential proteins TRPC1/4/5 and TRPC3/6. Moreover, stromal interacting molecule 1 (STIM1) and Orai proteins are upregulated in proliferating cells. Increased expression of IP3 receptors, SERCA2b, TRPCs, Orai(s), and STIM1 in proliferating ASMCs suggests that these proteins play a critical role in an altered Ca2+ handling that occurs during vascular growth and remodeling.

Enhanced capacitative calcium entry and TRPC channel gene expression in human LES smooth muscle

2003 ◽  
Vol 284 (6) ◽  
pp. G1074-G1083 ◽  
Author(s):  
Jian Wang ◽  
Lisanne G. Laurier ◽  
Stephen M. Sims ◽  
Harold G. Preiksaitis
Keyword(s):  
Gene Expression ◽  
Smooth Muscle ◽  
Transient Receptor Potential ◽  
Smooth Muscles ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Transcriptional Expression ◽  
External Application ◽  
Intracellular Ca ◽  
Transient Receptor

Transient receptor potential channel ( TRPC) genes encode Ca2+-permeable channels mediating capacitative Ca2+ entry (CCE), which maintains intracellular Ca2+ stores. We compared TRPC gene expression and CCE in human esophageal body (EB) and lower esophageal sphincter (LES), because these smooth muscles have distinct contractile functions that are likely associated with different Ca2+ regulatory mechanisms. Circular layer smooth muscle cells were grown in primary culture. Transcriptional expression of TRPC genes was compared by semiquantitative RT-PCR. CCE was measured by fura 2 Ca2+ fluorescence after blockade of sarcoplasmic reticulum Ca2+-ATPase with thapsigargin. mRNA for TRPC1, TRPC3, TRPC4, TRPC5, and TRPC6was identified in EB and LES. TRPC3 and TRPC4were more abundant in LES than EB. Basal concentration of free intracellular Ca2+ ([Ca2+]i) was similar in cells from LES (138 ± 8 nmol/l) and EB (110 ± 6 nmol/l) and increased with ACh (10 μmol/l; 650 ± 28 and 590 ± 21 nmol/l, respectively). With zero Ca2+ in bath, thapsigargin (2 μmol/l) increased [Ca2+]i more in LES (550 ± 22 nmol/l) than EB (250 ± 15 nmol/l, P < 0.001). Subsequent external application of 1 mmol/l Ca2+ increased [Ca2+]i more in LES (585 ± 35 nmol/l) than EB (295 ± 21 nmol/l, P < 0.001), indicating enhanced CCE in LES. This demonstrates CCE and TRPC transcriptional expression in human esophageal smooth muscle. In LES cells, enhanced CCE and expression of TRPC3 and TRPC4 may contribute to the physiological characteristics that distinguish LES from EB.

scholarly journals Reconstitution of lysosomal NAADP-TRP-ML1 signaling pathway and its function in TRP-ML1−/− cells

2011 ◽  
Vol 301 (2) ◽  
pp. C421-C430 ◽  
Author(s):  
Fan Zhang ◽  
Ming Xu ◽  
Wei-Qing Han ◽  
Pin-Lan Li
Keyword(s):  
Transient Receptor Potential ◽  
Human Fibroblasts ◽  
Receptor Potential ◽  
Channel Activity ◽  
Lysosomal Storage ◽  
Release Channel ◽  
Lipid Trafficking ◽  
Intracellular Ca ◽  
Mucolipidosis Iv ◽  
Transient Receptor

It is well known that the mutation of TRP-ML1 (transient receptor potential-mucolipin-1) causes mucolipidosis IV, a lysosomal storage disease. Given that lysosomal nicotinic acid adenine dinucleotide phosphate (NAADP)-Ca2+ release channel activity is associated with TRP-ML1, the present study was designed to test the hypothesis that NAADP regulates lysosome function via activation of TRP-ML1 channel activity. Using lysosomal preparations from wild-type (TRP-ML1+/+) human fibroblasts, channel reconstitution experiments demonstrated that NAADP (0.01–1.0 μM) produced a concentration-dependent increase in TRP-ML1 channel activity. This NAADP-induced activation of TRP-ML1 channels could not be observed in lysosomes from TRP-ML1−/− cells, but was restored by introducing a TRP-ML1 transgene into these cells. Microscopic Ca2+ fluorescence imaging showed that NAADP significantly increased intracellular Ca2+ concentration to 302.4 ± 74.28 nM (vs. 180 ± 44.13 nM of the basal) in TRP-ML1+/+ cells, but it had no effect in TRP-ML1−/− cells. If a TRP-ML1 gene was transfected into TRP-ML1−/− cells, the Ca2+ response to NAADP was restored to the level comparable to TRP-ML1+/+ cells. Functionally, confocal microscopy revealed that NAADP significantly enhanced the dynamic interaction of endosomes and lysosomes and the lipid delivery to lysosomes in TRP-ML1+/+ cells. This functional action of NAADP was abolished in TRP-ML1−/− cells, but restored after TRP-ML1 gene was rescued in these cells. Our results suggest that NAADP increases lysosomal TRP-ML1 channel activity to release Ca2+, which promotes the interaction of endosomes and lysosomes and thereby regulates lipid transport to lysosomes. Failure of NAADP-TRP-ML1 signaling may be one of the important mechanisms resulting in intracellular lipid trafficking disorder and consequent mucolipidosis.

scholarly journals Transient Receptor Potential Channels in the Vasculature

2015 ◽  
Vol 95 (2) ◽  
pp. 645-690 ◽  
Author(s):  
Scott Earley ◽  
Joseph E. Brayden
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Muscle Cells ◽  
Intracellular Ca ◽  
Transient Receptor

The mammalian genome encodes 28 distinct members of the transient receptor potential (TRP) superfamily of cation channels, which exhibit varying degrees of selectivity for different ionic species. Multiple TRP channels are present in all cells and are involved in diverse aspects of cellular function, including sensory perception and signal transduction. Notably, TRP channels are involved in regulating vascular function and pathophysiology, the focus of this review. TRP channels in vascular smooth muscle cells participate in regulating contractility and proliferation, whereas endothelial TRP channel activity is an important contributor to endothelium-dependent vasodilation, vascular wall permeability, and angiogenesis. TRP channels are also present in perivascular sensory neurons and astrocytic endfeet proximal to cerebral arterioles, where they participate in the regulation of vascular tone. Almost all of these functions are mediated by changes in global intracellular Ca2+ levels or subcellular Ca2+ signaling events. In addition to directly mediating Ca2+ entry, TRP channels influence intracellular Ca2+ dynamics through membrane depolarization associated with the influx of cations or through receptor- or store-operated mechanisms. Dysregulation of TRP channels is associated with vascular-related pathologies, including hypertension, neointimal injury, ischemia-reperfusion injury, pulmonary edema, and neurogenic inflammation. In this review, we briefly consider general aspects of TRP channel biology and provide an in-depth discussion of the functions of TRP channels in vascular smooth muscle cells, endothelial cells, and perivascular cells under normal and pathophysiological conditions.

scholarly journals Satellite glial cells in sensory ganglia express functional transient receptor potential ankyrin 1 that is sensitized in neuropathic and inflammatory pain

2020 ◽  
Vol 16 ◽  
pp. 174480692092542 ◽  
Author(s):  
Seung Min Shin ◽  
Brandon Itson-Zoske ◽  
Yongsong Cai ◽  
Chensheng Qiu ◽  
Bin Pan ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Nerve Injury ◽  
Glial Cells ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Allyl Isothiocyanate ◽  
Sensory Ganglia ◽  
Satellite Glial Cells ◽  
Intracellular Ca ◽  
Transient Receptor

Transient receptor potential ankyrin 1 (TRPA1) is well documented as an important molecule in pain hypersensitivity following inflammation and nerve injury and in many other cellular biological processes. Here, we show that TRPA1 is expressed not only by sensory neurons of the dorsal root ganglia (DRG) but also in their adjacent satellite glial cells (SGCs), as well as nonmyelinating Schwann cells. TRPA1 immunoreactivity is also detected in various cutaneous structures of sensory neuronal terminals, including small and large caliber cutaneous sensory fibers and endings. The SGC-expressed TRPA1 is functional. Like DRG neurons, dissociated SGCs exhibit a robust response to the TRPA1-selective agonist allyl isothiocyanate (AITC) by an increase of intracellular Ca2+ concentration ([Ca2+]i). These responses are abolished by the TRPA1 antagonist HC030031 and are absent in SGCs and neurons from global TRPA1 null mice. SGCs and neurons harvested from DRG proximal to painful tissue inflammation induced by plantar injection of complete Freund’s adjuvant show greater AITC-evoked elevation of [Ca2+]i and slower recovery compared to sham controls. Similar TRPA1 sensitization occurs in both SGCs and neurons during neuropathic pain induced by spared nerve injury. Together, these results show that functional TRPA1 is expressed by sensory ganglia SGCs, and TRPA1 function in SGCs is enhanced after both peripheral inflammation and nerve injury, and suggest that TRPA1 in SGCs may contribute to inflammatory and neuropathic pain.

scholarly journals Capacitative Ca2+ entry in agonist-induced pulmonary vasoconstriction

2001 ◽  
Vol 280 (5) ◽  
pp. L870-L880 ◽  
Author(s):  
Sharon S. McDaniel ◽  
Oleksandr Platoshyn ◽  
Jian Wang ◽  
Ying Yu ◽  
Michele Sweeney ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Channel Blocker ◽  
Receptor Potential ◽  
Rt Pcr ◽  
Pulmonary Vasoconstriction ◽  
Store Depletion ◽  
Intracellular Ca ◽  
Gene Transcripts ◽  
Transient Receptor ◽  
Sustained Increase

Agonist-induced increases in cytosolic Ca2+ concentration ([Ca2+]cyt) in pulmonary artery (PA) smooth muscle cells (SMCs) consist of a transient Ca2+ release from intracellular stores followed by a sustained Ca2+ influx. Depletion of intracellular Ca2+ stores triggers capacitative Ca2+ entry (CCE), which contributes to the sustained increase in [Ca2+]cyt and the refilling of Ca2+ into the stores. In isolated PAs superfused with Ca2+-free solution, phenylephrine induced a transient contraction, apparently by a rise in [Ca2+]cyt due to Ca2+ release from the intracellular stores. The transient contraction lasted for 3–4 min until the Ca2+ store was depleted. Restoration of extracellular Ca2+ in the presence of phentolamine produced a contraction potentially due to a rise in [Ca2+]cyt via CCE. The store-operated Ca2+ channel blocker Ni2+ reduced the store depletion-activated Ca2+ currents, decreased CCE, and inhibited the CCE-mediated contraction. In single PASMCs, we identified, using RT-PCR, five transient receptor potential gene transcripts. These results suggest that CCE, potentially through transient receptor potential-encoded Ca2+ channels, plays an important role in agonist-mediated PA contraction.

Sign in / Sign up

Export Citation Format

Share Document