Role of TRPV4 channels in high glucose-induced neurotoxicity in a neuronal-like cell model

Neurological dysfunction caused by hyperglycemia has been linked to abnormal activity of the transient receptor potential vanilloid (TRPV) channel family, especially in diabetic neuropathy. TRPV4 functions as a sensor of oxidative stress related to acute high glucose toxicity in various models. However, the effects of acute high glucose on TRPV4 channels have not been studied in SH-SY5Y cells. The purpose of this study was to evaluate how a high glucose environment influences TRPV4 channels in SH-SY5Y cells. The MTT assay was used to evaluate cell viability in SH-SY5Y cells, and a dose-response curve was created to identify the glucose concentration that causes toxicity. To measure TRPV4 channel activity, calcium levels were analyzed using spectrofluorometry with FURA-2 AM in cell suspensions. Measurements lasted 100 seconds, with a TRPV4-selective agonist, GSK1016790A (100 nM), applied at 50 seconds. qPCR assays measured the effect of high glucose (HG) conditions on relative TRPV4 gene expression using the ΔΔCt method, and Western blot experiments assessed protein expression. Under HG conditions (45 mM, 24 hours), inhibition of TRPV4 with GSK2913874 (100 nM) significantly improved cell viability. HG conditions suppressed TRPV4-dependent calcium increase compared to basal conditions. A significant reduction in gene and protein expression of TRPV4 was observed in SH-SY5Y cells exposed to HG. Overall, these data indicate that HG environments decrease TRPV4 channel activity and expression, which can impair neuronal function by disrupting calcium signaling.