Objective To explore the effect of hydrostatic pressure on intracellular free calcium concentration ([Ca2+]i) and the gene expression of transient receptor potential vanilloid (TRPV) in cultured human bladder smooth muscle cells (hb-SMCs), and to prel iminarily probe into the possible molecular mechanism of hb-SMCs prol iferation stimulated by hydrostatic pressure. Methods The passage 6-7 hb-SMCs were loaded with Ca2+ indicator Fluo-3/AM. When the hb-SMCs were under 0 cm H2O (1 cm H2O=0.098 kPa) (group A) or 200 cm H2O hydrostatic pressure for 30 minutes (group B) and then removing the 200 cm H2O hydrostatic pressure (group C), the [Ca2+]i was measured respectively by inverted laser anningconfocal microscope. When the hb-SMCs were given the 200 cm H2O hydrostatic pressure for 0 hour, 2 hours, 6 hours, 2 hours, and 24 hours, the mRNA expressions of TRPV1, TRPV2, and TRPV4 were detected by RT-PCR technique. Results The [Ca2+]i of group A, group B, and group C were (100.808 ± 1.724), (122.008 ± 1.575), and (99.918 ± 0.887) U, respectively; group B was significantly higher than groups A and C (P lt; 0.001). The [Ca2+]i of group C decreased to the base l ine level of group A after removing the pressure (t=0.919, P=0.394). The TRPV1, TRPV2, and TRPV4 genes expressed in hb-SMCs under 200 cm H2O hydrostatic pressure at 0 hour, 2 hours, 6 hours, 12 hours, and 24 hours, but the expressions had no obvious changes with time. There was no significant difference in the expressions of TRPV1, TRPV2, and TRPV4 among 3 groups (P gt; 0.05). Conclusion The [Ca2+]i of hb-SMCs increases significantly under high hydrostatic pressure. As possible genes in stretch-activated cation channel, the TRPV1, TRPV2, and TRPV4 express in hb-SMCs under 200 cm H2O hydrostatic pressure. It is possible that the mechanical pressure regulates the [Ca2+]i of hb-SMCs by opening the stretch-activated cation channel rather than up-regulating its expression.
ObjectiveTo explore the metabolic changes during the differentiation of 3T3-L1 adipocytes caused by the treatment of the transient receptor potential vanilloid 4 (TRPV4)-specific agonist GSK1016790A basing on ultra-performance liquid chromatography-mass spectrometry technology. MethodsMouse 3T3-L1 cells were treated with GSK1016790A at different concentrations (0.1, 1, and 10 μmol/L), and the effect of drugs on cell proliferation was detected by cell counting kit-8 method. A mature adipocyte model was constructed, and GSK1016790A was used to activate TRPV4 channel protein activity and verify the expression levels of TRPV4 and triglycerides. Cell metabolites were collected for metabolomic studies, differential metabolites were screened between groups, and related metabolic pathways were analyzed. Results After GSK1016790A intervened in mature adipocytes, the expression levels of TRPV4 mRNA and triglycerides in cells were significantly upregulated (P<0.05). Metabolomics detection found that GSK1016790A screened a total of 45 differential metabolites such as 2-amino-1,3,4-octadecanetriol, linoleic acid, sphingosine, sphinganine, sn-glycerol-3-phosphate and uridine, mainly involving 13 possible metabolic pathways such as sphingolipid metabolism and biosynthesis of unsaturated fatty acids. Conclusion GSK1016790A may promote adipogenesis in adipocytes by activating TRPV4 channel protein activity, and at the same time participate in regulating metabolic pathways such as the biosynthesis of unsaturated fatty acids pathway and sphingolipid metabolism pathway, affecting lipid metabolism in adipocytes.