Expression and role of the TRPC family in TGF-β1-induced calcium influx in podocytes / 生理学报

The TRPC family consists of multiple important cationic channels in mammals that participate in a variety of physiological and pathological processes. Our previous studies have shown that transforming growth factor-β1 (TGF-β1) increases the expression of TRPC6 in podocytes, but the roles of other members of the TRPC family in podocytes require further investigation. In this study, we investigated the effect of TGF-β1 on the expression of the TRPC family and the role of the TRPC family in the changes of the intracellular Ca2+ concentration ([Ca2+]i) in podocytes induced by TGF-β1. The model of podocyte injury was established by treatment with TGF-β1 in immortalized glomerular podocytes (MPC5) in vitro. qRT-PCR and Western blot were used to detect the effect of TGF-β1 on the mRNA and protein expression of each TRPC family member. After the expression of each TRPC family member was knocked down by a siRNA-based approach and blocked by SKF96365, respectively, free cytosolic Ca2+ was measured using the fluorescent Ca2+ indicator Fluo-3/AM, and the dynamic change of [Ca2+]i in podocytes was detected by a dynamic high-speed calcium imaging system. The results showed that TGF-β1 increased the protein expression of TRPC1/3/6 in podocytes, but had no effects on the protein expression of TRPC4. The protein expression levels of TRPC5/7 were only affected by 4 ng/mL and 8 ng/mL TGF-β1, respectively. TGF-β1 increased TRPC1/3/6 mRNA levels in podocytes, however had no effects on TRPC4/5/7 mRNA. TGF-β1 significantly increased [Ca2+]i in podocytes. Knockdown of TRPC1/4/5/7 in podocytes had no significant effect on the [Ca2+]i induced by TGF-β1, but TRPC3/6 knockdown significantly decreased the [Ca2+]i. There was no significant difference in the [Ca2+]i between the TRPC6 siRNA-treated group and SKF96365-treated group, but the [Ca2+]i of the TRPC3 siRNA-treated group was significantly higher than that of SKF96365-treated group. These results demonstrate that TGF-β1 increases the expression of the TRPC1/3/6 in podocytes. TGF-β1 increases [Ca2+]i in podocytes, which is dependent on the TRPC3/6 expression. Our results also suggest that the effect of TRPC6 on [Ca2+]i in podocytes may be greater than that of TRPC3.

A child with diffuse mesangial sclerosis caused by a missense mutation of TRPC6 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic etiology and clinical outcome of a child with steroid-resistant nephrotic syndrome and diffuse mesangial sclerosis.@*METHODS@#Genomic DNA was extracted from peripheral blood leukocytes of the proband and his parents. Targeted capture - next generation sequencing and Sanger sequencing were carried out. Candidate variant was verified by segregation analysis in his family.@*RESULTS@#A heterozygous missense variant of the TRPC6 gene, namely c.325G>A (p.Gly109Ser), was detected in the proband. The same variant was not detected in either parent. According to the guidelines for the interpretation of sequence variants developed by American College of Medical Genetics and Genomics, the variant was predicted as pathogenic.@*CONCLUSION@#The missense variant of the TRPC6 gene probably underlay the diffuse mesangial sclerosis in this patient. Above finding has expanded the phenotypic spectrum of the TRPC6 gene.

Recent advances in the research on mechanisms underlying podocyte-specific gene mutation-related steroid-resistant nephrotic syndrome / 中国当代儿科杂志

Steroid-resistant nephrotic syndrome poses a significant clinical challenge. Its pathogenesis has not been fully elucidated. In recent years, numerous studies have shown that podocyte-specific gene mutations may play important roles in the development of steroid-resistant nephrotic syndrome. Among the identified genes mutated in podocytes include NPHS2, NPHS1, WT1, TRPC6, MDR1, PLCE1, LMX1B, and LAMB2. This review aims to summarize the characteristics of these mutated genes in podocytes. The putative role for these podocyte-specific mutated genes in the pathogenesis, diagnosis, treatment and prognosis of steroid-resistant nephrotic syndrome is also discussed.

Effects of TRPC6 on invasibility of low-differentiated prostate cancer cells

OBJECTIVE@#To study the expression of TRPC6 among prostate cancer cells, establish high expression cell lines of TRPC6, and to provide potential cell mode for prostate cancer oncogenesis and development.@*METHODS@#Occurrence and development of prostate cancer cells, PC3, PC-3 m DU145, 22 rv1, LNCaP and normal prostate epithelial cells in the PrEC TRPC6 expression level were detected by QPCR method. Calcium phosphate transfection method was used to package retrovirus pLEGFP-N1-TRPC6 and pLEGFP-N1-vector and infect the prostate cancer cells, a stable high expression of TRPC6 prostate cancer cells. Sable cell lines of TRPC6, matrix metalloproteinase (MMP) 2, MMP9 expression was detected by QPCR and Western blot. Change of cell invasion ability was detected by Transwell.@*RESULTS@#The expression level of prostate cancer cells TRPC6 were higher than control group PrEC cells. Among TPRC6 the expression of cell line PC 3 transfer potential wre the lowest, and high transfer cell line PC-3M express was the highest. Real-time fluorescent quantitative PCR and western blot results showed that after filter, the seventh generation of cell TRPC6 protein and mRNA expression levels were higher than the control group obviously. Transwell experimental results showed that the overexpression of TRPC6 could promote the invasion ability of PC3 prostate cancer cells.@*CONCLUSIONS@#TRPC6 expressed in prostate cancer cells is in disorder, and its action may be associated with the invasion and metastasis of prostate cancer cells; successful establishment of stable high expression of TRPC6 prostate cancer cells primarily confirm the invasion-trigger ability of TRPC6 on prostate cancer, and lay down the Foundation for exploring the TRPC6's role in the occurrence and development of prostate cancer mechanism.

Essential role of TRPC6 in the proliferation of gastric cancer and its mechanism / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the essential role and mechanism of TRPC6 gene in the development of gastric cancer.</p><p><b>METHODS</b>The expression of TRPC6 protein was assessed in gastric cancer tissues and normal tissues adjacent to the cancer from 30 patients with gastric cancer. The inhibiting effect of TRPC6 activity on cell growth, cell cycle of a human gastric cancer cell line AGS cells, tumor progression and development of xenografted human gastric cancer in a mouse model was tested using dominant-negative mutant TRPC6 (DNC6). The survival of mice bearing xenografted tumors in the GFP and DNC6 was compared using Kaplan-Meier analysis. All statistical tests were two-sided.</p><p><b>RESULTS</b>The TRPC6 protein in the tumor tissues and para-tumor tissues was (21.60 ± 8.32)% versus (7.14 ± 2.24)%. After transfection of DNC6 virus for 24 hours, 48 hours, 72 hours and 96 hours, the growth inhibition rates of gastric cancer cells were (36.90 ± 1.13)%, (44.06 ± 2.17)%, (52.12 ± 2.76)% and (50.89 ± 1.97)%, respectively. The clone formation rates of control group and DNC6 group were (14.70 ± 3.00)% versus (43.80 ± 7.00)%. After transfection with DNC6 virus for 0, 24, 36 and 48 hours, the G(2)/M phase arrest was (20.34 ± 1.98)%, (24.31 ± 2.37)%, (27.70 ± 2.36)%, (35.10 ± 3.0)% in the DNC6 group and (18.40 ± 2.01)%, (18.0% ± 1.72)%, (17.50 ± 1.74)%, (16.80 ± 1.71)% in the control group, respectively. Inhibition of TRPC6 activity also reduced the subcutaneous tumor volume in the mouse models with xenografted human tumors (P < 0.05).</p><p><b>CONCLUSION</b>In the preclinical models tested, TRPC6 channels are essential for gastric cancer development via regulation of G(2)/M phase transition.</p>