Role of the transient receptor potential (TRP) channel gene expressions and TRP melastatin (TRPM) channel gene polymorphisms in obesity-related metabolic syndrome.

OBJECTIVE: Metabolic syndrome (MetS) is correlated with increased cardiovascular risk and characterized by several factors, including visceral obesity, hypertension, dyslipidemia, and insulin resistance. The etiology of MetS is complex, and can be influenced by genetic susceptibility. The aim of this study was to investigate a possible association of transient receptor potential (TRP) channels gene expressions and TRP melastatin (TRPM) gene polymorphisms with MetS in a Turkish population. PATIENTS AND METHODS: A total of 142 patients with obesity-related MetS and 166 healthy controls with similar age and sex were enrolled to this study. For polymorphism studies, genomic DNA from the participants was analyzed by a BioMark 96.96 dynamic array system (Fluidigm, South San Francisco, CA, USA). For gene expression studies, mRNA from blood samples was extracted, and real time polymerase chain reaction on the BioMark HD system was performed.
RESULTS: There was an increase in A allele (64.6% in patients vs. 49.5% in controls) and decrease in G allele frequencies (35.4% in patients vs. 50.5% in control, p = 0.0019) of the TRPM5 gene rs4929982 (Arg578Gln) polymorphism. We also observed that the distribution of genotype and allele frequencies of the TRPM8 gene rs12472151 in MetS patients were significantly different from controls (p < 0.0001). Although there were marked decreases in TRPC1, TRPC3, TRPM2, TRPM5, TRPV4, TRPV5, TRPV6, MCOLN2 (TRPML2), and MCOLN3 (TRPML3) gene expressions, an augmentation was noted in TRPC6 gene expression.
CONCLUSIONS: Genetic polymorphisms in TRPM5 and TRPM8 genes may modify individual susceptibility to MetS in the Turkish population. This study also revealed that there is a significant relationship between TRP channels gene expressions and MetS.