Depletion of Intracellular Ca
            2+
            Stores Stimulates the Translocation of Vanilloid Transient Receptor Potential 4-C1 Heteromeric Channels to the Plasma Membrane

Mammalian homologues of the Drosophila canonical Transient Receptor Potential (TRPC) protein have been proposed to encode the store-operated Ca2+ influx (SOC) channel(s). This study examines the role of TRPC1 in the SOC mechanism of retinal cells. htrpc1 transcript was detected in bovine retinal and in human adult retinal pigment epithelial (ARPE) cells. Western blot analysis also confirmed the expression of TRPC1 protein in neuronal cells including retina and ARPE cells. To determine the role of TRPC1 protein in retinal cells, TRPC1 was recombinantly expressed in ARPE cells and changes in intracellular Ca2+ were analyzed. ARPE cells stably transfected with htrp1 cDNA displayed 2-fold higher Ca2+ influx with no significant increase in the basal influx. Consistent with this the overexpressed TRPC1 protein was localized in the plasma membrane region of ARPE cells. Interestingly, both bovine retinal tissues and ARPE cells showed that TRPC1 protein co-localizes and could be co-immunoprecipitated with β-tubulin. Disruption of tubulin by colchicine significantly decreased both plasma membrane staining of the TRPC1 protein and Ca2+ influx in ARPE cells. These results suggest that TRPC1 channel protein is expressed in retinal cells, further, targeting/retention of the TRPC1 protein to the plasma membrane in retinal cells is mediated via its interaction with β-tubulin.

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Distinct calcium regulation of TRPM7 mechanosensitive channels at plasma membrane microdomains visualized by FRET-based single cell imaging

Scientific Reports ◽

10.1038/s41598-021-97326-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Irina Starostina ◽

Yoon-Kwan Jang ◽

Heon-Su Kim ◽

Jung-Soo Suh ◽

Sang-Hyun Ahn ◽

...

Keyword(s):

Plasma Membrane ◽

Transient Receptor Potential ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Receptor Potential ◽

Membrane Microdomains ◽

Mechanosensitive Channels ◽

Intracellular Ca ◽

Transient Receptor ◽

Plasma Membrane Microdomains

AbstractTransient receptor potential subfamily M member 7 (TRPM7), a mechanosensitive Ca2+ channel, plays a crucial role in intracellular Ca2+ homeostasis. However, it is currently unclear how cell mechanical cues control TRPM7 activity and its associated Ca2+ influx at plasma membrane microdomains. Using two different types of Ca2+ biosensors (Lyn-D3cpv and Kras-D3cpv) based on fluorescence resonance energy transfer, we investigate how Ca2+ influx generated by the TRPM7-specific agonist naltriben is mediated at the detergent-resistant membrane (DRM) and non-DRM regions. This study reveals that TRPM7-induced Ca2+ influx mainly occurs at the DRM, and chemically induced mechanical perturbations in the cell mechanosensitive apparatus substantially reduce Ca2+ influx through TRPM7, preferably located at the DRM. Such perturbations include the disintegration of lipid rafts, microtubules, or actomyosin filaments; the alteration of actomyosin contractility; and the inhibition of focal adhesion and Src kinases. These results suggest that the mechanical membrane environment contributes to the TRPM7 function and activity. Thus, this study provides a fundamental understanding of how the mechanical aspects of the cell membrane regulate the function of mechanosensitive channels.

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Inositol lipids and TRPC channel activation

Biochemical Society Symposium ◽

10.1042/bss2007c04 ◽

2007 ◽

Vol 74 ◽

pp. 37-45 ◽

Cited By ~ 12

Author(s):

James W. Putney

Keyword(s):

Plasma Membrane ◽

Phospholipase C ◽

Transient Receptor Potential ◽

Calcium Signalling ◽

Receptor Potential ◽

Breakdown Product ◽

Channel Activation ◽

Inositol Lipids ◽

Transient Receptor ◽

Secondary Mechanism

The original hypothesis put forth by Bob Michell in his seminal 1975 review held that inositol lipid breakdown was involved in the activation of plasma membrane calcium channels or ‘gates’. Subsequently, it was demonstrated that while the interposition of inositol lipid breakdown upstream of calcium signalling was correct, it was predominantly the release of Ca2+ that was activated, through the formation of Ins(1,4,5)P3. Ca2+ entry across the plasma membrane involved a secondary mechanism signalled in an unknown manner by depletion of intracellular Ca2+ stores. In recent years, however, additional non-store-operated mechanisms for Ca2+ entry have emerged. In many instances, these pathways involve homologues of the Drosophila trp (transient receptor potential) gene. In mammalian systems there are seven members of the TRP superfamily, designated TRPC1–TRPC7, which appear to be reasonably close structural and functional homologues of Drosophila TRP. Although these channels can sometimes function as store-operated channels, in the majority of instances they function as channels more directly linked to phospholipase C activity. Three members of this family, TRPC3, 6 and 7, are activated by the phosphoinositide breakdown product, diacylglycerol. Two others, TRPC4 and 5, are also activated as a consequence of phospholipase C activity, although the precise substrate or product molecules involved are still unclear. Thus the TRPCs represent a family of ion channels that are directly activated by inositol lipid breakdown, confirming Bob Michell's original prediction 30 years ago.

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

Molecular Pain ◽

10.1177/1744806920925425 ◽

2020 ◽

Vol 16 ◽

pp. 174480692092542 ◽

Cited By ~ 2

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.

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Role of capacitative Ca2+ entry in bronchial contraction and remodeling

Journal of Applied Physiology ◽

10.1152/japplphysiol.00722.2001 ◽

2002 ◽

Vol 92 (4) ◽

pp. 1594-1602 ◽

Cited By ~ 100

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.

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Diacylglycerol activates the influx of extracellular cations in T-lymphocytes independently of intracellular calcium-store depletion and possibly involving endogenous TRP6 gene products

Biochemical Journal ◽

10.1042/bj3640245 ◽

2002 ◽

Vol 364 (1) ◽

pp. 245-254 ◽

Cited By ~ 60

Author(s):

Alessandra GAMBERUCCI ◽

Emanuele GIURISATO ◽

Paola PIZZO ◽

Maristella TASSI ◽

Roberta GIUNTI ◽

...

Keyword(s):

Plasma Membrane ◽

T Lymphocytes ◽

Peripheral Blood ◽

Transient Receptor Potential ◽

Human Peripheral Blood ◽

Receptor Potential ◽

Animal Cells ◽

Bivalent Cation ◽

Intracellular Calcium Store ◽

Transient Receptor

In Jurkat and human peripheral blood T-lymphocytes, 1-oleoyl-2-acetyl-sn-glycerol (OAG), a membrane-permeant analogue of diacylglycerol, activated the influx of Ca2+, Ba2+ and Sr2+. OAG also caused plasma-membrane depolarization in Ca2+-free media that was recovered by the addition of bivalent cation, indicating the activation of Na+ influx. OAG-induced cation influx was (i) mimicked by the natural dacylglycerol 1-stearoyl-2-arachidonyl-sn-glycerol, (ii) not blocked by inhibiting protein kinase C or in the absence of phopholipase C activity and (iii) blocked by La3+ and Gd3+. Differently from OAG, both thapsigargin and phytohaemagglutinin activated a potent influx of Ca2+, but little influx of Ba2+ and Sr2+. Moreover, the influx of Ca2+ activated by thapsigargin and that activated by OAG were additive. Furthermore, several drugs (i.e. econazole, SKF96365, carbonyl cyanide p-trifluoromethoxyphenylhydrazone, 2-aminoethoxy diphenylborate and calyculin-A), while inhibiting the influx of Ca2+ induced by both thapsigargin and phytohaemagglutinin, did not affect OAG-stimulated cation influx. Transient receptor potential (TRP) 3 and TRP6 proteins have been shown previously to be activated by diacylglycerol when expressed heterologously in animal cells [Hofmann, Obukhov, Schaefer, Harteneck, Gudermann and Schultz (1999) Nature (London) 397, 259–263]. In both Jurkat and peripheral blood T-lymphocytes, mRNA encoding TRP proteins 1, 3, 4 and 6 was detected by reverse transcriptase PCR, and the TRP6 protein was detected by Western blotting in a purified plasma-membrane fraction. We conclude that T-cells express a diacylglycerol-activated cation channel, unrelated to the channel involved in capacitative Ca2+ entry, and associated with the expression of TRP6 protein.

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Capacitative Ca2+ entry in agonist-induced pulmonary vasoconstriction

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.2001.280.5.l870 ◽

2001 ◽

Vol 280 (5) ◽

pp. L870-L880 ◽

Cited By ~ 111

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.

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Analgesic Effects of Lipid Raft Disruption by Sphingomyelinase and Myriocin via Transient Receptor Potential Vanilloid 1 and Transient Receptor Potential Ankyrin 1 Ion Channel Modulation

Frontiers in Pharmacology ◽

10.3389/fphar.2020.593319 ◽

2021 ◽

Vol 11 ◽

Author(s):

Ádám Horváth ◽

Maja Payrits ◽

Anita Steib ◽

Boglárka Kántás ◽

Tünde Biró-Süt ◽

...

Keyword(s):

Plasma Membrane ◽

Lipid Raft ◽

Transient Receptor Potential ◽

Trp Channels ◽

Receptor Potential ◽

Membrane Microdomains ◽

Neuronal Cultures ◽

Transient Receptor Potential Vanilloid ◽

Peripheral Sensitization ◽

Transient Receptor

Transient Receptor Potential (TRP) Vanilloid 1 and Ankyrin 1 (TRPV1, TRPA1) cation channels are expressed in nociceptive primary sensory neurons, and integratively regulate nociceptor and inflammatory functions. Lipid rafts are liquid-ordered plasma membrane microdomains rich in cholesterol, sphingomyelin and gangliosides. We earlier showed that lipid raft disruption inhibits TRPV1 and TRPA1 functions in primary sensory neuronal cultures. Here we investigated the effects of sphingomyelinase (SMase) cleaving membrane sphingomyelin and myriocin (Myr) prohibiting sphingolipid synthesis in mouse pain models of different mechanisms. SMase (50 mU) or Myr (1 mM) pretreatment significantly decreased TRPV1 activation (capsaicin)-induced nocifensive eye-wiping movements by 37 and 41%, respectively. Intraplantar pretreatment by both compounds significantly diminished TRPV1 stimulation (resiniferatoxin)-evoked thermal allodynia developing mainly by peripheral sensitization. SMase (50 mU) also decreased mechanical hyperalgesia related to both peripheral and central sensitizations. SMase (50 mU) significantly reduced TRPA1 activation (formalin)-induced acute nocifensive behaviors by 64% in the second, neurogenic inflammatory phase. Myr, but not SMase altered the plasma membrane polarity related to the cholesterol composition as shown by fluorescence spectroscopy. These are the first in vivo results showing that sphingolipids play a key role in lipid raft integrity around nociceptive TRP channels, their activation and pain sensation. It is concluded that local SMase administration might open novel perspective for analgesic therapy.

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Functional characterization of transient receptor potential channels in mouse urothelial cells

AJP Renal Physiology ◽

10.1152/ajprenal.00599.2009 ◽

2010 ◽

Vol 298 (3) ◽

pp. F692-F701 ◽

Cited By ~ 101

Author(s):

Wouter Everaerts ◽

Joris Vriens ◽

Grzegorz Owsianik ◽

Giovanni Appendino ◽

Thomas Voets ◽

...

Keyword(s):

Plasma Membrane ◽

Patch Clamp ◽

Calcium Imaging ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Functional Expression ◽

Sensory Function ◽

Trp Channel ◽

Urothelial Cells ◽

Transient Receptor

The bladder urothelium is currently believed to be a sensory structure, contributing to mechano- and chemosensation in the bladder. Transient receptor potential (TRP) cation channels act as polymodal sensors and may underlie some of the receptive properties of urothelial cells. However, the exact TRP channel expression profile of urothelial cells is unclear. In this study, we have performed a systematic analysis of the molecular and functional expression of various TRP channels in mouse urothelium. Urothelial cells from control and trpv4−/− mice were isolated, cultured (12–48 h), and used for quantitative real-time PCR, immunocytochemistry, calcium imaging, and whole cell patch-clamp experiments. At the mRNA level, TRPV4, TRPV2, and TRPM7 were the most abundantly expressed TRP genes. Immunohistochemistry showed a clear expression of TRPV4 in the plasma membrane, whereas TRPV2 was more prominent in the cytoplasm. TRPM7 was detected in the plasma membrane as well as cytoplasmic vesicles. Calcium imaging and patch-clamp experiments using TRP channel agonists and antagonists provided evidence for the functional expression of TRPV4, TRPV2, and TRPM7 but not of TRPA1, TRPV1, and TRPM8. In conclusion, we have demonstrated functional expression of TRPV4, TRPV2, and TRPM7 in mouse urothelial cells. These channels may contribute to the (mechano)sensory function of the urothelial layer and represent potential targets for the treatment of bladder dysfunction.

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Nifedipine-activated Ca2+ permeability in newborn rat cortical collecting duct cells in primary culture

AJP Cell Physiology ◽

10.1152/ajpcell.2001.280.5.c1193 ◽

2001 ◽

Vol 280 (5) ◽

pp. C1193-C1203 ◽

Cited By ~ 5

Author(s):

Laura Valencia ◽

Michel Bidet ◽

Sonia Martial ◽

Elsa Sanchez ◽

Estela Melendez ◽

...

Keyword(s):

Primary Culture ◽

Transient Receptor Potential ◽

Collecting Duct ◽

Primary Cultures ◽

Receptor Potential ◽

Cortical Collecting Duct ◽

Newborn Rat ◽

Adult Rat ◽

Intracellular Ca ◽

Transient Receptor

To characterize Ca2+ transport in newborn rat cortical collecting duct (CCD) cells, we used nifedipine, which in adult rat distal tubules inhibits the intracellular Ca2+concentration ([Ca2+]i) increase in response to hormonal activation. We found that the dihydropyridine (DHP) nifedipine (20 μM) produced an increase in [Ca2+]i from 87.6 ± 3.3 nM to 389.9 ± 29.0 nM in 65% of the cells. Similar effects of other DHP (BAY K 8644, isradipine) were also observed. Conversely, DHPs did not induce any increase in [Ca2+]i in cells obtained from proximal convoluted tubule. In CCD cells, neither verapamil nor diltiazem induced any rise in [Ca2+]i. Experiments in the presence of EGTA showed that external Ca2+ was required for the nifedipine effect, while lanthanum (20 μM), gadolinium (100 μM), and diltiazem (20 μM) inhibited the effect. Experiments done in the presence of valinomycin resulted in the same nifedipine effect, showing that K+ channels were not involved in the nifedipine-induced [Ca2+]i rise. H2O2also triggered [Ca2+]i rise. However, nifedipine-induced [Ca2+]i increase was not affected by protamine. In conclusion, the present results indicate that 1) primary cultures of cells from terminal nephron of newborn rats are a useful tool for investigating Ca2+transport mechanisms during growth, and 2) newborn rat CCD cells in primary culture exhibit a new apical nifedipine-activated Ca2+ channel of capacitive type (either transient receptor potential or leak channel).

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