Intron specific polymorphic site of vaspin gene along with vaspin circulatory levels can influence pathophysiology of type 2 diabetes

Abstract

Vaspin, an insulin-sensitizing adipokine, has been associated with type 2 diabetes (T2D). The present study aimed to investigate the distribution of genotypes and high-risk alleles of vaspin genetic variants (rs77060950 G/T and rs2236242 A/T), in Gujarat subpopulation (India). Genomic DNA isolated from PBMCs was used to genotype vaspin polymorphisms by PCR-RFLP and ARMS-PCR from 502 controls and 478 patients. RNA isolated from visceral adipose tissue (VAT) of 22 controls and 20 patients was used to assess vaspin transcript levels by qPCR while the vaspin titre of the subjects was assayed using ELISA. Phenotypic characteristics of Fasting Blood Glucose (FBG), BMI and plasma lipid profile were estimated and analyzed for the genotype-phenotype correlation. We identified a significant association of rs2236242 A/T with T2D as the TT genotype conferred a 3.087-fold increased risk. The TT genotype showed association with increased FBG, BMI and Triglycerides levels. Increased GA, GT and TA haplotype frequencies, decreased VAT transcript and vaspin protein levels in T2D patients was observed, which were further negatively correlated with FBG and BMI. In conclusion, rs2274907 A/T polymorphism is strongly associated with reduced vaspin transcript and protein levels, and related metabolic alterations that may play a role in the advancement of T2D.

Keywords: Adipokine; Dyslipidemia; Genotype-phenotype correlation; Haplotype; Obesity; Single nucleotide polymorphism.