Effect of Zuoguiwan on Expression of Ca2+ Transport Pathway-related Protein in Ovariectomized Rats / 中国实验方剂学杂志

Objective::To explore the effect of Zuoguiwan on the bone mineral density (BMD) and the expressions of Ca2+ transport-associated protein in ovariectomized rats. Method::The 48 female SD rats were randomly divided into six groups: normal group, model group, sham operation group, estrogen group(0.167 mg·kg-1) and low and high-dose Zuoguiwan groups(9.6, 38.4 g·kg-1), with 10 rats in each group. Except for the sham-operated group, the ovariectomized rats in the other groups received the bilateral ovariectomy. Therapeutic intervention was given in each group for 3 months after the establishment of the model. After 12 weeks, BMD was measured using dualenergy X-ray absorptiometry. Tartrated presistant acid phosphatse(TRACP) and serum calcium were detected by biochemical kits.Protein expression in Ca2+ transport (Bone tissue) was detected by Western blot. Result::Compared with the normal group, the serum calcium of the model group was decreased(P<0.01). Compared with the normal group, BMD of the model group was decreased (P<0.01). The serum calcium of rats in high-dose group and western medicine group was higher than that of model group(P<0.01). BMD in model group was lower than that of Zuoguiwan groups and estrogen group(P<0.05). There was no significant difference in TRACP among the groups. Nilestriol and Zuoguiwan can down-regulate the expressions of TRPV5, NCX1, CaBP-D28K and PMCA1b in bone tissue of castrated rats(P<0.05, P<0.01). Conclusion::Zuoguiwan can down-regulate the expressions of Ca2+ transport-associated proteins (Bone tissues) in rat osteoclasts, with an efficacy on osteoporosis.

Effect of TRPV5 and TRPV6 channels on the biological behaviors of SW480 colon cancer cell line / 中国肿瘤临床

Objective:To investigate the role of TRPV5 and TRPV6 in intracellular calcium regulation and biological behaviors of SW480 colon cancer cells. Methods:qRT-PCR, Western blot, and immunocytochemistry were applied to determine the mRNA and protein ex-pression levels of TRPV5 and TRPV6 in SW480 colon cancer cell line upon treatment with TRPV5 and TRPV6 agonist, 1-25(OH)2D3, and inhibitor, CuCl2. The change of intracellular Ca2+level was examined with a confocal laser scanning microscope. Scratch test, MTT, and TUNEL assays were used to analyze the cell migration, proliferation, and apoptosis, respectively. Results:As an agonist of TRPV5 and TRPV6, 1-25(OH)2D3 significantly up-regulated the mRNA and protein expression levels of TRPV5 and TRPV6 in SW480 cell lines. On the other hand, CuCl2, being an inhibitor of TRPV5 and TRPV6, effectively down-regulated the TRPV5 and TRPV6 mRNA and protein expres-sion levels (P<0.05). The intracellular calcium concentration in SW480 cell line significantly increased upon treatment with 1-25 (OH)2D3, and significantly decreased with CuCl2 treatment (P<0.05). 1-25(OH)2D3 promoted cell proliferation and migration, and inhibit-ed apoptosis of SW480 cell in a time-and dose-dependent manner (P<0.05). However, CuCl2 significantly repressed cell proliferation and migration and induced apoptosis (P<0.05). Conclusion: TRPV5 and TRPV6 can affect the biological behaviors of colon cancer SW480 cells by regulating intracellular Ca2+level.

Effects of RLMF and RLMP on Expression of TRPV5 in IgA Nephropathy Rat Renal Tissue / 医药导报

Objective To investigate the effects of Rosa Laevigata Michx Flavoid( RLMF) and Rosa laevigata Michx Polysaccharose (RLMP) on expression of TRPV5 in IgA Nephropathy (IgAN) rat renal tissue. Methods Forty Sprague-Dawley rats were randomly assigned to four groups.The rat model of IgA nephropathy was induced by intragastric administration of bovine serumalbumin and injections of LPS and CC14.Eight weeks later,the rats with IgAN were treated with RLMF or RLMP (4 weeks), or normal saline.Rats was sacrificed at thirteenth weeks, and RNA was extracted from the kidney.Expression of TRPV5 in tubulointerstitial tissues were analyzed by fluorescent quantitative RT-PCR. Results After RFLP intervention,the expression levels of TRPV5 were markedly increased (P<0.01) than model control group,while decreased (P<0.05) than normal control group but had no significance with model control group after RFLF intervention. Conclusion TRPV5 expression is decreased in IgAN,and RLMP can adjust TRPV5 expression and improve renal function of IgAN.

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

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-D(28K), 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 calcium-vitamin 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.

The Expression and Implication ofTRPV5, Calbindin-D28k and NCX1 in Idiopathic Hypercalciuria / 华中科技大学学报（医学）（英德文版）

Summary: The expression of calcium epithelium TRPV5, alcium binding protein Calbindin-D28k and Na+/Ca2+ exchanger NCX1 was detected in renal distal convoluted tubule, and their effects on urine calcium reabsorption and the possible pathogenic mechanism in idiopathic hypercalciuria (IH) were investigated. Genetic hypercalciuric stone-forming (GHS) rats were chosen as animal models to study urine calcium reabsorption and IH. The cognate female and male rats that had maximal urine calcium were matched to breed next generation. Twelve GHS rats and 12 normal control (NC) SD rats were selected. Western blot and real time quantitative PCR were used to detect the protein and gene expression of TRPV5, Calbindin-D28k and NCX1 respectively. The expression levels of TRPV5 protein and mRNA in GHS rats were significantly lower than in NC rats (P<0.05). Western blot revealed that the expression levels of Caibindin-D28k in GHS rats and NC rats were 0.49±0.02 and 0.20±0.01 respectively, with the difference being significant between them (P<0.05). By using real time quantitative PCR, it was found that there was no significant difference in Calbindin-28k mRNA expression levels between GHS rats and NC rats (P0.05). There was no significant difference in the NCX1 expression between GHS rats and NC rats (P0.05). It was suggested that TRPV5 and Caibindin-D28k might play an important role in urine calcium reabsorption and IH, but they differently contributed to the pathogenesis: The down-regulation of TRPV5 decreases urine calcium reabsorption, directly leading to loss of the urine calcium and resulting in hypercalciuria, and the increased Calbindin-D28k expression could relieve, neutralize and decrease intracellular Ca2+ concentration to maintain calcium balance. NCX1 is not the key protein in urine calcium reabsorption.