Potential role of TRPV5 in the formation of epidermal calcium gradients and the epidermal permeability barrier

김현정 ( Hyun Jung Kim ),Se Kyoo Jeong,Ji Min Kim,Min Kyung Jeong,Seung Hun Lee 한국피부장벽학회 2009 한국피부장벽학회지 Vol.11 No.2

TRPV5 and 6, which belong to the superfamily of transient receptor potential channels, constitute the apical Ca2+ entry mechanism in active Ca2+ transport in kidney and intestine. Considering the calcium gradient in viable epidermis, it is interesting that the extracellular calcium ion at the SG-SC junction is abruptly disappeared. Currently, it is unclear which receptors or ion channels are underlying the acute loss of calcium ions at SG-SC junction. In this study, we have investigated the potential role of TRPV5 and 6 in the regulation of epidermal calcium ion concentration. Firstly, epidermal expressions of TRPV5 and 6 were observed in the suprabasal layer of normal skin, whereas in the lesional skin of atopic dermatitis and psoriasis, epidermal expression of TRPV5 and 6 were lost. Treatments of psoriasis, however, resulted in the re-appearance of TRPV5 and 6 expressions in epidermis. In an animal model, acute disruption of epidermal permeability barrier induced the decrease of TRPV 5 and 6 expressions, and the recovery of those proteins was parallel to that of calcium gradient. The occlusion after barrier disruption, which inhibits the recovery of calcium gradient, also inhibited TRPV5 and 6 expressions. These results suggested that TRPV5 and 6 are closely related with the epidermal calcium gradient. Since the extracellular pH environment regulates the expressions of TRPV5 and 6, it can be suggested that TRPV5 and 6 are potential sensor for pH environment, which controls calcium movement and keratinocyte differentiation.

Expression and Prognostic Roles of TRPV5 and TRPV6 in Non-Small Cell Lung Cancer after Curative Resection

Fan, Hong,Shen, Ya-Xing,Yuan, Yun-Feng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Purpose: We investigated the expression of epithelial $Ca^{2+}$ channel transient receptor potential vanilloid (TRPV) 5 and 6 in non-small-cell lung cancer (NSCLC) and assessed their prognostic role in patients after surgical resection. Materials and Methods: From January 2008 to January 2009, 145 patients who had undergone surgical resection of NSCLCs were enrolled in the study. Patient clinical characteristics were retrospectively reviewed. Fresh tumor samples as well as peritumor tissues were analyzed for TRPV5/6 expression using immune-histochemistry (IHC) and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Patients were grouped based on their TRPV5 and TRPV6 levels in the tumor tissues, followed up after surgery, and statistically analyzed to examine the prognostic roles of TRPV5 and TRPV6 on patients' survival after surgical resection of NSCLCs. Results: Using IHC, among the 145 patients who had undergone surgical resection of NSCLCs, strong protein expression (grade${\geq}2$) of TRPV5 and TRPV6 was observed in a lower percentage of primary tumor tissues than in non-tumor tissues of same patients. Similar findigns were obtained with the RT-PCR test for mRNA levels. Decreased overall mRNA levels of TRPV5 and TRPV6 were associated with a worse overall survival rate (p=0.004 and p=0.003 respectively) and shorter recurrence-free survival (p<0.001 and p<0.001 respectively). The combining effect of TRPV5 and TRPV6 on survival was further investigated using multivariate analysis. The results showed that a combination of low expression of TRPV5 and TRPV6 could be an independent predictor of poor recurrence-free survival (p=0.002). Conclusions: Decreased expression of TRPV5/6 in tumor tissues was observed in NSCLC patients and was associated with shorter median survival time after surgical resection. Combined expression of TRPV5 and TRPV6 in tumor tissues demonstrated promising prognostic value in NSCLC patients.

Transient Receptor Potential Vanilloid 1 Expression and Functionality in MCF-7 Cells: A Preliminary Investigation

Cristina Vercelli,Raffaella Barbero,Barbara Cuniberti,Silvia Racca,Giuliana Abbadessa,Francesca Piccione,Giovanni Re 한국유방암학회 2014 Journal of breast cancer Vol.17 No.4

Purpose: Transient receptor potential vanilloid 1 (TRPV1) is a nonselectivecation channel belonging to the transient receptor potentialfamily, and it is expressed in different neoplastic tissues. Its activation is associated with regulation of cancer growth andprogression. The aim of this research was to study the expressionand pharmacological characteristics of TRPV1 in cells derivedfrom human breast cancer MCF-7 cells. Methods: TRPV1presence was assessed by binding studies and Western blotting. Receptor binding characteristics were evaluated through competitionassays, while 3-(4,5-dimethylthiazol-2-yl)-2,5,-dipheyltetrazoliumbromide reduction assays were performed to confirman early hypothesis regarding the modulation of cancer cell proliferation. The functionality of TRPV1 was evaluated by measuringCa2+ uptake in the presence of increasing concentrations ofTRPV1 agonists and antagonists. Results: Binding studies identifieda single class of TRPV1 (Bmax 1,492±192 fmol/mg protein),and Western blot showed a signal at 100 kDa corresponding tothe molecular weight of human TRPV1. Among the different testedagonists and antagonists, anandamide (Ki: 2.8×10-11 M) and5-iodoresiniferatoxin (5-I-RTX) (Ki: 5.6×10-11 M) showed the highestdegrees of affinity for TRPV1, respectively. All tested TRPV1agonists and antagonists caused a significant (p<0.05) decreasein cell growth rate in MCF-7 cells. For agonists and antagonists,the efficacy of tested compounds displayed the following rankorder: resiniferatoxin>anandamide>capsaicin and 5-I-RTX=capsazepine, respectively. Conclusion: These data indicate thatboth TRPV1 agonists and antagonists induce significant inhibitionof MCF-7 cell growth. Even though the mechanisms involvedin the antiproliferative effects of TRPV1 agonists and antagonistsshould be further investigated, it has been suggestedthat agonists cause desensitization of the receptor, leading to alterationin Ca2+-influx regulation. By contrast, antagonists causea functional block of the receptor with consequent fatal dysregulationof cell homeostasis.

카나비노이드 수용체 활성화 및 TRPV1 억제를 통한 arachidonoyl-serotonin (AA-5-HT)의 진통 효과

심은진(Eunjin Sym),심원식(Won-Sik Shim) 대한약학회 2021 약학회지 Vol.65 No.4

Pain is a noxious sensation caused by tissue damage, which can severely interfere with a person’s quality of life. Although numerous analgesics are available for eradicating pain, there remain limitations in terms of safety and efficacy. This review focuses on arachidonoyl-serotonin (AA-5-HT) − an endogenous lipid with a putative antinociceptive effect. After detailed investigation, previous studies have revealed that AA-5-HT can stimulate the cannabinoid system, which results in the inhibition of pain sensation. Moreover, AA-5-HT can inhibit the action of TRPV1, which is a nonselective cation channel that mediates pain signals in the nervous system. This dual effect makes AA-5-HT a potentially safe and potent analgesic. This review summarizes the roles of the cannabinoid system and TRPV1 in pain sensation, and the function of AA-5-HT in pain modulation.

Inhibition of Bone Resorption by Econazole in Rat Osteoclast-like Cells through Suppressing TRPV5

Peng Yan,Tang Li,Meng Bo,Liu Die,Liang Xing 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.6

Osteoclasts are primary bone resorption cells and intervention in osteoclast activation is considered an effective therapeutic approach to treatment of bone diseases involving osteoclasts. TRPV5 was detected in osteoclasts and it has been thought to take part in the transportation of the degraded calcium in the resorption lacuna, which is essential for bone resorption. The aim of the present study was to examine the effects of a modulator of calcium dynamics, econazole, on the expression of TRPV5 and bone resorption activity in rat osteoclast-like cells (OLCs). OLCs were obtained by co-culturing rat bone marrow cells with osteoblasts and then culturing with different concentrations of econazole (0.01, 0.1, 1.0, 10.0 μmol/L). Cell counting and staining protocols were used to determine whether econazole influenced the survival of OLCs. Expression of TRPV5 in response to econazole treatment was assessed by western blotting. Bone resorption activity of OLCs was determined by measuring the resorption area of dentin slices with a microscope and a digital image analysis system. Additionally, Ca^2+ inside OLCs was tested. We found that econazole inhibited expression of TRPV5 in a dose dependent manner while it had no influence on the survival of OLCs and it therefore inhibited bone resorption activity in rat OLCs. Ca^2+ inside OLCs increased, suggesting a limited compensatory mechanism to make up for inhibition of TRPV5 effects.

High Dose Vitamin D3 Attenuates the Hypocalciuric Effect of Thiazide in Hypercalciuric Rats

장혜련,이재욱,김세중,허남주,이정환,김효상,정지용,오윤규,나기영,한진석,주권욱 대한의학회 2010 Journal of Korean medical science Vol.25 No.9

Thiazide is known to decrease urinary calcium excretion. We hypothesized that thiazide shows different hypocalciuric effects depending on the stimuli causing hypercalciuria. The hypocalciuric effect of hydrochlorothiazide (HCTZ) and the expression of transient receptor potential vanilloid 5 (TRPV5), calbindin-D28K, and several sodium transporters were assessed in hypercalciuric rats induced by high calcium diet and vitamin D3. Urine calcium excretion and the expression of transporters were measured from 4 groups of Sprague-Dawley rats;control, HCTZ, high calcium-vitamin D, and high calcium-vitamin D with HCTZ groups. HCTZ decreased urinary calcium excretion by 51.4% in the HCTZ group and only 15% in the high calcium-vitamin D with HCTZ group. TRPV5 protein abundance was not changed by HCTZ in the high calcium-vitamin D with HCTZ group compared to the high calciumvitamin D group. Protein abundance of NHE3, SGLT1, and NKCC2 decreased in the hypercalciuric rats, and only SGLT1 protein abundance was increased by HCTZ in the hypercalciuric rats. The hypocalciuric effect of HCTZ is attenuated in high calcium and vitamin D-induced hypercalciuric rats. This attenuation seems to have resulted from the lack of HCTZ’s effect on protein abundance of TRPV5 in severe hypercalciuric condition induced by high calcium and vitamin D.

Dietary Calcium and 1,25-Dihydroxyvitamin D₃ Regulate Transcription of Calcium Transporter Genes in Calbindin-D9k Knockout Mice

KO, Sang-Hwan,LEE, Geun-Shik,VO, Thuy T. B.,JUNG, Eui-Man,CHOI, Kyung-Chul,CHEUNG, Ki-Wha,KIM, Jae Wha,PARK, Jong-Gil,OH, Goo Taeg,JEUNG, Eui-Bae Society for Reproduction and Development 2009 Journal of Reproduction and Development Vol.55 No.2

<P>The effect(s) of oral calcium and vitamin D<SUB>3</SUB> were examined on the expression of duodenal and renal active calcium transport genes, i.e., calbindin-D9k (<I>CaBP-9k</I>) and calbindin-D28k (<I>CaBP-28k</I>), transient receptor potential cation channels (<I>TRPV5</I> and <I>TRPV6</I>), Na<SUP>+</SUP>/Ca<SUP>2+</SUP> exchanger 1 (<I>NCX1</I>) and plasma membrane calcium ATPase 1b (<I>PMCA1b</I>), in <I>CaBP-9k</I> KO mice. Wild-type (WT) and KO mice were provided with calcium and vitamin D<SUB>3</SUB>-deficient diets for 10 weeks. The deficient diet significantly decreased body weights compared with the normal diet groups. The serum calcium concentration of the WT mice was decreased by the deficient diet but was unchanged in the KO mice. The deficient diet significantly increased duodenal transcription of <I>CaBP-9k</I> and <I>TRPV6</I> in the WT mice, but no alteration was observed in the KO mice. In the kidney, the deficient diet significantly increased renal transcripts of <I>CaBP-9k</I>, <I>TRPV6</I>, <I>PMCA1b</I>, <I>CaBP-28k</I> and <I>TRPV5</I> in the WT mice but did not alter calcium-relating genes in the KO mice. Two potential mediators of calcium-processing genes, vitamin D receptor (VDR) and parathyroid hormone receptor (PTHR), have been suggested to be useful for elucidating these differential regulations in the calcium-related genes of the KO mice. Expression of VDR was not significantly affected by diet or the KO mutation. Renal <I>PTHR</I> mRNA levels were reduced by the diet, and reduced expression was also seen in the KO mice given the normal diet. Taken together, these results suggest that the active calcium transporting genes in KO mice may have resistance to the deficiency diet of calcium and vitamin D<SUB>3</SUB>.</P>