Diabetes modulates capacitative calcium entry and expression of transient receptor potential canonical channels in human saphenous vein

We report the sequence, structure and distribution of a novel transient receptor potential (trp) homologue from Xenopus, Xtrp, determined by screening an oocyte cDNA library. On the basis of sequence similarity and predicted structure, Xtrp appears to be a homologue of mammalian trp1 proteins. Two polyclonal antibodies raised against distinct regions of the Xtrp sequence revealed Xtrp expression in various Xenopus tissues, and the localization of Xtrp at the plasma membrane of Xenopus oocytes and HeLa cells. Since capacitative calcium entry into Xenopus oocytes has been shown previously to be substantially inhibited by trp1 antisense oligonucleotides [Tomita, Kaneko, Funayama, Kondo, Satoh and Akaike (1998) Neurosci. Lett. 248, 195-198] we suggest that Xtrp may underlie capacitative calcium entry in Xenopus tissues.

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Up-Regulation of Transient Receptor Potential Canonical 1 (TRPC1) following Sarco(endo)plasmic Reticulum Ca2+ ATPase 2 Gene Silencing Promotes Cell Survival: A Potential Role for TRPC1 in Darier's Disease

Molecular Biology of the Cell ◽

10.1091/mbc.e06-03-0251 ◽

2006 ◽

Vol 17 (10) ◽

pp. 4446-4458 ◽

Cited By ~ 56

Author(s):

Biswaranjan Pani ◽

Eric Cornatzer ◽

William Cornatzer ◽

Dong-Min Shin ◽

Mark R. Pittelkow ◽

...

Keyword(s):

Cell Survival ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Calcium Entry ◽

Hacat Cells ◽

Transient Receptor Potential Canonical ◽

Darier's Disease ◽

Plasmic Reticulum ◽

Store Operated Calcium Entry ◽

Transient Receptor

The mechanism(s) involved in regulation of store operated calcium entry in Darier's disease (DD) is not known. We investigated the distribution and function of transient receptor potential canonical (TRPC) in epidermal skin cells. DD patients demonstrated up-regulation of TRPC1, but not TRPC3, in the squamous layers. Ca2+ influx was significantly higher in keratinocytes obtained from DD patients and showed enhanced proliferation compared with normal keratinocytes. Similar up-regulation of TRPC1 was also detected in epidermal layers of SERCA2+/− mice. HaCaT cells expressed TRPC1 in the plasma membrane. Expression of sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA)2 small interfering RNA (siRNA) in HaCaT cells increased TRPC1 levels and thapsigargin-stimulated Ca2+ influx, which was blocked by store-operated calcium entry inhibitors. Thapsigargin-stimulated intracellular Ca2+ release was decreased in DD cells. DD keratinocytes exhibited increased cell survival upon thapsigargin treatment. Alternatively, overexpression of TRPC1 or SERCA2-siRNA in HaCaT cells demonstrated resistance to thapsigargin-induced apoptosis. These effects were dependent on external Ca2+ and activation of nuclear factor-κB. Isotretinoin reduced Ca2+ entry in HaCaT cells and decreased survival of HaCaT and DD keratinocytes. These findings put forward a novel consequence of compromised SERCA2 function in DD wherein up-regulation of TRPC1 augments cell proliferation and restrict apoptosis. We suggest that the anti-apoptotic effect of TRPC1 could potentially contribute to abnormal keratosis in DD.

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Physiological Induction of Transient Receptor Potential Canonical Proteins, Calcium Entry Channels, in Human Myometrium: Influence of Pregnancy, Labor, and Interleukin-1β

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2003-031428 ◽

2004 ◽

Vol 89 (3) ◽

pp. 1291-1300 ◽

Cited By ~ 43

Author(s):

A. Dalrymple ◽

D. M. Slater ◽

L. Poston ◽

R. M. Tribe

Keyword(s):

Mrna Expression ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Calcium Entry ◽

Human Myometrium ◽

Physiological Regulation ◽

Transient Receptor Potential Canonical ◽

Active Labor ◽

Transient Receptor ◽

Trpc Proteins

Abstract This study investigated gestational regulation of transient receptor potential canonical (TrpC) proteins, putative calcium entry channels in human myometrium, and the potential modulation of TrpC expression by IL–1β, a cytokine implicated in labor. Total RNA and proteins were isolated from myometrial biopsies obtained from NP women, pregnant women at term not in labor (TNL), or term active labor (TAL) and from primary cultured human myometrial smooth muscle cells incubated with IL–1β or IL–1β with or without nimesulide. Semiquantitative RT-PCR demonstrated significant up-regulation of TrpC1 in TAL and TNL (P ≤ 0.01) and TrpC6 (P ≤ 0.01) and TrpC7 (P ≤ 0.05) in TAL samples. TrpC3 and TrpC4 mRNA expression was unaffected. Western blot demonstrated significant up-regulation of TrpC1 in TAL and TNL (P ≤ 0.05) and TrpC3 (P ≤ 0.01), TrpC4 (P ≤ 0.05), and TrpC6 (P ≤ 0.01) in TAL samples. IL–1β did not alter TrpC1, 3, 4, 6, or 7 mRNA expression; but IL–1β exclusively up-regulated TrpC3 protein expression (P ≤ 0.05). TrpC3 up-regulation was unaffected by cyclooxygenase blockade. These data demonstrate physiological regulation of TrpC mRNA and protein and suggest an important role for TrpC proteins in human myometrium during labor.

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