148 DIFFERENTIAL REGULATION OF CALCIUM TRANSPORT GENES, I.E., Na+/Ca2+ EXCHANGERS, TRANSIENT RECEPTOR POTENTIAL CATION CHANNEL 6 AND CALBINDINS, IN THE DIVERSE PLACENTAL TISSUES OF CALBINDIN-D9k AND -28k KNOCKOUT MICE VIA PUTATIVE STEROIDS

2012 ◽  
Vol 24 (1) ◽  
pp. 186
Author(s):  
T. H. Koo ◽  
E. B. Jeung
Keyword(s):  
Calcium Binding ◽  
Calcium Transport ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Differential Regulation ◽  
Wild Type ◽  
Rt Pcr ◽  
Calbindin D9k ◽  
Ef Hand ◽  
Transient Receptor

During pregnancy, the placenta represents the establishment of an intimate connection between mother and fetus that is specific to mammals. Calbindins [Calbindin-D9k (CaBP-9k) and -D28k (CaBP-28k)] are proteins possessing EF-hand motifs that have a high affinity for Ca2+ ions and play an important role in the regulation and buffering of Ca2+ in the various tissues. Many types of calcium channels, intracellular calcium binding proteins, Na+/Ca2+ exchangers (NCX) and transient receptor potential cation channels (TRPV) have been found in the placenta. In this study, the calcium channel in maternal-fetal Ca2+ transport was investigated using the phenotypes of wild-type, CaBP-9k, CaBP-28k and CaBP-9k/28k knockout (KO) mouse models. Expressions of calcium transport genes in 3 dissected sections of placenta (MP: maternal, CP: central, FP: fetal) were examined by real-time RT-PCR (RT-qPCR) and Western blot analysis at gestational Day 19 in these mice. The level of TRPV6 mRNA and protein was highest in the MP and CP of CaBP-28k KO mice and the FP of CaBP-9k KO mice compared with other sections of KO mice. The level of CaBP-9k was significantly induced in CaBP-28k KO mice in MP, CP and FP compared with in WT mice, which levels were elevated from maternal to fetal sections. The expression of CaBP-28k mRNA and protein was reduced in CaBP-9k KO mice compared with WT in the 3 sections of placenta. The expression of NCX1 mRNA and protein was higher in all KO mice than in WT in MP and NCX1 was highest in CaBP-28k KO mice in CP, but strong in CaBP-9k KO mice in FP compared with other strains. These results indicate that TRPV6 and NCX1 participate in transferring calcium ions between maternal and fetal compartments and alteration of CaBP-9k/28k is involved in the intracellular Ca2+ buffering system among WT and KO mice. These results taken together indicate that TRPV6 and CaBP-9k genes may play a role as a key element in controlling placental calcium transport during pregnancy.

scholarly journals Evidence for a Role of Prolactin in Calcium Homeostasis: Regulation of Intestinal Transient Receptor Potential Vanilloid Type 6, Intestinal Calcium Absorption, and the 25-Hydroxyvitamin D3 1α Hydroxylase Gene by Prolactin

Endocrinology ◽  
2010 ◽  
Vol 151 (7) ◽  
pp. 2974-2984 ◽  
Author(s):  
Dare V. Ajibade ◽  
Puneet Dhawan ◽  
Adam J. Fechner ◽  
Mark B. Meyer ◽  
J. Wesley Pike ◽  
...  
Keyword(s):  
Vitamin D ◽  
Calcium Homeostasis ◽  
Calcium Transport ◽  
Transient Receptor Potential ◽  
Prolactin Receptor ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Calbindin D9k ◽  
Intestinal Calcium Transport ◽  
Transient Receptor

Increased calcium transport has been observed in vitamin D-deficient pregnant and lactating rats, indicating that another factor besides 1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) is involved in intestinal calcium transport. To investigate prolactin as a hormone involved in calcium homeostasis, vitamin D-deficient male mice were injected with 1,25(OH)2D3, prolactin, or prolactin + 1,25(OH)2D3. Prolactin alone (1 μg/g body weight 48, 24, and 4 h before termination) significantly induced duodenal transient receptor potential vanilloid type 6 (TRPV6) mRNA (4-fold) but caused no change in calbindin-D9k. Combined treatment with 1,25(OH)2D3 and prolactin resulted in an enhancement of the 1,25(OH)2D3 induction of duodenal TRPV6 mRNA, calbindin-D9k mRNA, and an induction of duodenal calcium transport [P < 0.05 compared with 1,25(OH)2D3 alone]. Because lactation is associated with an increase in circulating 1,25(OH)2D3, experiments were done to determine whether prolactin also has a direct effect on induction of 25-hydroxyvitamin D3 1α hydroxylase [1α(OH)ase]. Using AOK B-50 cells cotransfected with the prolactin receptor and the mouse 1α(OH)ase promoter −1651/+22 cooperative effects between prolactin and signal transducer and activator of transcription 5 were observed in the regulation of 1α(OH)ase. In addition, in prolactin receptor transfected AOK B-50 cells, prolactin treatment (400 ng/ml) and signal transducer and activator of transcription 5 significantly induced 1α(OH)ase protein as determined by Western blot analysis. Thus, prolactin, by multiple mechanisms, including regulation of vitamin D metabolism, induction of TRPV6 mRNA, and cooperation with 1,25(OH)2D3 in induction of intestinal calcium transport genes and intestinal calcium transport, can act as an important modulator of vitamin D-regulated calcium homeostasis.

scholarly journals Active Intestinal Calcium Transport in the Absence of Transient Receptor Potential Vanilloid Type 6 and Calbindin-D9k

Endocrinology ◽  
2008 ◽  
Vol 149 (6) ◽  
pp. 3196-3205 ◽  
Author(s):  
Bryan S. Benn ◽  
Dare Ajibade ◽  
Angela Porta ◽  
Puneet Dhawan ◽  
Matthias Hediger ◽  
...  
Keyword(s):  
Vitamin D ◽  
Calcium Transport ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Fold Increase ◽  
Transient Receptor Potential Vanilloid ◽  
Low Calcium Diet ◽  
Calbindin D9k ◽  
Intestinal Calcium Transport ◽  
Transient Receptor

To study the role of the epithelial calcium channel transient receptor potential vanilloid type 6 (TRPV6) and the calcium-binding protein calbindin-D9k in intestinal calcium absorption, TRPV6 knockout (KO), calbindin-D9k KO, and TRPV6/calbindin-D9k double-KO (DKO) mice were generated. TRPV6 KO, calbindin-D9k KO, and TRPV6/calbindin-D9k DKO mice have serum calcium levels similar to those of wild-type (WT) mice (∼10 mg Ca2+/dl). In the TRPV6 KO and the DKO mice, however, there is a 1.8-fold increase in serum PTH levels (P < 0.05 compared with WT). Active intestinal calcium transport was measured using the everted gut sac method. Under low dietary calcium conditions there was a 4.1-, 2.9-, and 3.9-fold increase in calcium transport in the duodenum of WT, TRPV6 KO, and calbindin-D9k KO mice, respectively (n = 8–22 per group; P > 0.1, WT vs. calbindin-D9k KO, and P < 0.05, WT vs. TRPV6 KO on the low-calcium diet). Duodenal calcium transport was increased 2.1-fold in the TRPV6/calbindin-D9k DKO mice fed the low-calcium diet (P < 0.05, WT vs. DKO). Active calcium transport was not stimulated by low dietary calcium in the ileum of the WT or KO mice. 1,25-Dihydroxyvitamin D3 administration to vitamin D-deficient null mutant and WT mice also resulted in a significant increase in duodenal calcium transport (1.4- to 2.0-fold, P < 0.05 compared with vitamin D-deficient mice). This study provides evidence for the first time using null mutant mice that significant active intestinal calcium transport occurs in the absence of TRPV6 and calbindin-D9k, thus challenging the dogma that TRPV6 and calbindin-D9k are essential for vitamin D-induced active intestinal calcium transport.

Effects of methylglyoxal on human cardiac fibroblast: roles of transient receptor potential ankyrin 1 (TRPA1) channels

2014 ◽  
Vol 307 (9) ◽  
pp. H1339-H1352 ◽  
Author(s):  
Gaku Oguri ◽  
Toshiaki Nakajima ◽  
Yumiko Yamamoto ◽  
Nami Takano ◽  
Tomofumi Tanaka ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Diabetic Cardiomyopathy ◽  
Cell Cycle Progression ◽  
Transient Receptor Potential ◽  
Cardiac Fibroblasts ◽  
Receptor Potential ◽  
Rt Pcr ◽  
Cycle Progression ◽  
Transient Receptor ◽  
Human Cardiac Fibroblasts

Cardiac fibroblasts contribute to the pathogenesis of cardiac remodeling. Methylglyoxal (MG) is an endogenous carbonyl compound produced under hyperglycemic conditions, which may play a role in the development of pathophysiological conditions including diabetic cardiomyopathy. However, the mechanism by which this occurs and the molecular targets of MG are unclear. We investigated the effects of MG on Ca2+ signals, its underlying mechanism, and cell cycle progression/cell differentiation in human cardiac fibroblasts. The conventional and quantitative real-time RT-PCR, Western blot, immunocytochemical analysis, and intracellular Ca2+ concentration [Ca2+]i measurement were applied. Cell cycle progression was assessed using the fluorescence activated cell sorting. MG induced Ca2+ entry concentration dependently. Ruthenium red (RR), a general cation channel blocker, and HC030031 , a selective transient receptor potential ankyrin 1 (TRPA1) antagonist, inhibited MG-induced Ca2+ entry. Treatment with aminoguanidine, a MG scavenger, also inhibited it. Allyl isothiocyanate, a selective TRPA1 agonist, increased Ca2+ entry. The use of small interfering RNA to knock down TRPA1 reduced the MG-induced Ca2+ entry as well as TRPA1 mRNA expression. The quantitative real-time RT-PCR analysis showed the prominent existence of TRPA1 mRNA. Expression of TRPA1 protein was confirmed by Western blotting and immunocytochemical analyses. MG promoted cell cycle progression from G0/G1 to S/G2/M, which was suppressed by HC030031 or RR. MG also enhanced α-smooth muscle actin expression. The present results suggest that methylglyoxal activates TRPA1 and promotes cell cycle progression and differentiation in human cardiac fibroblasts. MG might participate the development of pathophysiological conditions including diabetic cardiomyopathy via activation of TRPA1.

scholarly journals Novel role of transient receptor potential vanilloid 2 in the regulation of cardiac performance

2014 ◽  
Vol 306 (4) ◽  
pp. H574-H584 ◽  
Author(s):  
Jack Rubinstein ◽  
Valerie M. Lasko ◽  
Sheryl E. Koch ◽  
Vivek P. Singh ◽  
Vinicius Carreira ◽  
...  
Keyword(s):  
Vascular Function ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Wild Type ◽  
Transient Receptor ◽  
Systolic And Diastolic Function ◽  
Myocyte Contractility

Transient receptor potential cation channels have been implicated in the regulation of cardiovascular function, but only recently has our laboratory described the vanilloid-2 subtype (TRPV2) in the cardiomyocyte, though its exact mechanism of action has not yet been established. This study tests the hypothesis that TRPV2 plays an important role in regulating myocyte contractility under physiological conditions. Therefore, we measured cardiac and vascular function in wild-type and TRPV2−/− mice in vitro and in vivo and found that TRPV2 deletion resulted in a decrease in basal systolic and diastolic function without affecting loading conditions or vascular tone. TRPV2 stimulation with probenecid, a relatively selective TRPV2 agonist, caused an increase in both inotropy and lusitropy in wild-type mice that was blunted in TRPV2−/− mice. We examined the mechanism of TRPV2 inotropy/lusitropy in isolated myocytes and found that it modulates Ca2+ transients and sarcoplasmic reticulum Ca2+ loading. We show that the activity of this channel is necessary for normal cardiac function and that there is increased contractility in response to agonism of TRPV2 with probenecid.

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.

Monosodium urate crystal interleukin-1β release is dependent on Toll-like receptor 4 and transient receptor potential V1 activation

Rheumatology ◽  
2019 ◽  
Author(s):  
Mateus F. Rossato ◽  
Carin Hoffmeister ◽  
Gabriela Trevisan ◽  
Fabio Bezerra ◽  
Thiago M. Cunha ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Synovial Fluid ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Acute Gout ◽  
Toll Like Receptor ◽  
Wild Type ◽  
Toll Like Receptor 4 ◽  
Transient Receptor ◽  
Nitrite Nitrate

AbstractObjectiveThe present study aimed to elucidate the mechanisms involved in MSU-induced IL-1β release in a rodent animal model of acute gout arthritis.MethodsPainful (mechanical and thermal hypersensitivity, ongoing pain and arthritis score) and inflammatory (oedema, plasma extravasation, cell infiltration and IL-1β release) parameters were assessed several hours after intra-articular injection of MSU (100 µg/articulation) in wild-type or knockout mice for Toll-like receptor 4 (TLR4), inducible nitric oxide synthase (iNOS), transient receptor potential (TRP) V1 and the IL-1 receptor (IL-1R). Also, wild-type animals were treated with clodronate, lipopolysaccharide from Rhodobacter sphaeroides (LPS-RS) (TLR4 antagonist), spleen tyrosine kinase (SYK) inhibitor (iSYK), aminoguanidine (AMG, an iNOS inhibitor) or SB366791 (TRPV1 antagonist). Nitrite/nitrate and IL-1β levels were measured on the synovial fluid of wild-type mice, 2 h after intra-articular MSU injections, or medium from macrophages stimulated for MSU (1000 μg) for 2 h.ResultsIntra-articular MSU injection caused robust nociception and severe inflammation from 2 up to 6 h after injection, which were prevented by the pre-treatment with clodronate, LPS-RS, iSYK, AMG and SB366791, or the genetic ablation of TLR4, iNOS, TRPV1 or IL-1R. MSU also increased nitrite/nitrate and IL-1β levels in the synovial fluid, which was prevented by clodronate, LPS-RS, iSYK and AMG, but not by SB366791. Similarly, MSU-stimulated peritoneal macrophages released nitric oxide, which was prevented by LPS-RS, iSYK and AMG, but not by SB366791, and released IL-1β, which was prevented by LPS-RS, iSYK, AMG and SB366791.ConclusionOur data indicate that MSU may activate TLR4, SYK, iNOS and TRPV1 to induce the release of IL-1β by macrophages, triggering nociception and inflammation during acute gout attack.

TRPC4 forms store-operated Ca2+ channels in mouse mesangial cells

2004 ◽  
Vol 287 (2) ◽  
pp. C357-C364 ◽  
Author(s):  
Xiaoxia Wang ◽  
Jennifer L. Pluznick ◽  
Peilin Wei ◽  
Babu J. Padanilam ◽  
Steven C. Sansom
Keyword(s):  
Transient Receptor Potential ◽  
Mesangial Cells ◽  
Receptor Potential ◽  
Immunocytochemical Staining ◽  
Rt Pcr ◽  
Fura 2 ◽  
Intracellular Ca ◽  
Transient Receptor ◽  
Ca2 Channels

Studies were performed to identify the molecular component responsible for store-operated Ca2+ entry in murine mesangial cells (MMC). Because the canonical transient receptor potential (TRPC) family of proteins was previously shown to comprise Ca2+-selective and -nonselective cation channels in a variety of cells, we screened TRPC1–TRPC7 with the use of molecular methods and the fura 2 method to determine their participation as components of the mesangial store-operated Ca2+ (SOC) channel. Using TRPC-specific primers and RT-PCR, we found that cultured MMC contained mRNA for TRPC1 and TRPC4 but not for TRPC2, TRPC3, TRPC5, TRPC6, and TRPC7. Immunocytochemical staining of MMC revealed predominantly cytoplasmic expression of TRPC1 and plasmalemmal expression of TRPC4. The role of TRPC4 in SOC was determined with TRPC4 antisense and fura 2 ratiometric measurements of intracellular Ca2+ concentration ([Ca2+]i). SOC was measured as the increase in [Ca2+]i after extracellular Ca2+ was increased from <10 nM to 1 mM in the continued presence of thapsigargin. We found that TRPC4 antisense, which reduced plasmalemmal expression of TRPC4, inhibited SOC by 83%. Incubation with scrambled TRPC4 oligonucleotides did not affect SOC. Immunohistochemical staining identified expressed TRPC4 in the glomeruli of mouse renal sections. The results of RT-PCR performed to distinguish between TRPC4-α and TRPC4-β were consistent with expression of both isoforms in brain but with only TRPC4-α expression in MMC. These studies show that TRPC4-α may form the homotetrameric SOC in mouse mesangial cells.

scholarly journals Mapping of CaM, S100A1 and PIP2-Binding Epitopes in the Intracellular N- and C-Termini of TRPM4

2020 ◽  
Vol 21 (12) ◽  
pp. 4323
Author(s):  
Kristyna Bousova ◽  
Ivan Barvik ◽  
Petr Herman ◽  
Kateřina Hofbauerová ◽  
Lenka Monincova ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Md Simulations ◽  
Protein Docking ◽  
Alanine Scanning Mutagenesis ◽  
Rational Drug ◽  
Transient Receptor ◽  
Endogenous Modulators

Molecular determinants of the binding of various endogenous modulators to transient receptor potential (TRP) channels are crucial for the understanding of necessary cellular pathways, as well as new paths for rational drug designs. The aim of this study was to characterise interactions between the TRP cation channel subfamily melastatin member 4 (TRPM4) and endogenous intracellular modulators—calcium-binding proteins (calmodulin (CaM) and S100A1) and phosphatidylinositol 4, 5-bisphosphate (PIP2). We have found binding epitopes at the N- and C-termini of TRPM4 shared by CaM, S100A1 and PIP2. The binding affinities of short peptides representing the binding epitopes of N- and C-termini were measured by means of fluorescence anisotropy (FA). The importance of representative basic amino acids and their combinations from both peptides for the binding of endogenous TRPM4 modulators was proved using point alanine-scanning mutagenesis. In silico protein–protein docking of both peptides to CaM and S100A1 and extensive molecular dynamics (MD) simulations enabled the description of key stabilising interactions at the atomic level. Recently solved cryo-Electron Microscopy (EM) structures made it possible to put our findings into the context of the entire TRPM4 channel and to deduce how the binding of these endogenous modulators could allosterically affect the gating of TRPM4. Moreover, both identified binding epitopes seem to be ideally positioned to mediate the involvement of TRPM4 in higher-order hetero-multimeric complexes with important physiological functions.

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