Mitochondrial uncoupling protein 2 (UCP2) gene polymorphism - 866 G/A in the promoter region is associated with type 2 diabetes mellitus among Kashmiri population of Northern India

Mol Biol Rep. 2023 Jan;50(1):475-483. doi: 10.1007/s11033-022-08055-z. Epub 2022 Nov 8.

Abstract

Objective: The study aimed to evaluate the association of UCP2 gene polymorphism - 866 G/A and its expression with diabetes predisposition in the North Indian population.

Methods: The study involved 850 subjects, including 425 each T2DM and control subjects. The serum metabolic and clinical parameters were estimated using standard protocols. The PCR-RFLP based genotyping was performed to determine UCP2 gene polymorphism, while the expression was measured by real-time quantitative PCR.

Results: The genotypic and allelic frequencies showed a significant difference in cases compared to controls (p < 0.05). The diabetes patients had a 4.2-fold decrease in UCP2 gene expression. The expression was 29.8 and 8.4 fold lower in diabetes patients with homozygous (AA) and heterozygous (GA) mutation at - 866 locus of UCP2 nucleotide sequence, respectively. When categorized according to age and BMI, the T2DM subjects with age ≥ 50 and BMI ≥ 25 had a 5.53 and 8.2-fold decrease in UCP2 expression, respectively. The diabetes subjects with homozygous and heterozygous mutation demonstrated a pathological increase in serum metabolic and clinical parameters, which corroborated with UCP2 gene expression, indicating a strong association between the two. Intriguingly, we did not find any association between - 866 G/A polymorphism of UCP2 with serum insulin levels.

Conclusion: Our investigation is the first among the studies conducted in Jammu and Kashmir to work on adipose tissue and UCP2 gene polymorphism. The association of - 866 G/A SNP of the UCP2 gene with its expression in diabetes patients appears to be an important genetic determinant in the progression of T2DM. Moreover, age ≥ 50 years and BMI ≥ 25 could be considered risk factors for developing T2DM in the studied population.

Keywords: Diabetes; Homozygous mutation; India; Kashmiri population; Obesity; UCP2.

MeSH terms

  • Diabetes Mellitus, Type 2* / epidemiology
  • Diabetes Mellitus, Type 2* / genetics
  • Genotype
  • Humans
  • Ion Channels / genetics
  • Middle Aged
  • Mitochondrial Proteins / genetics
  • Polymorphism, Single Nucleotide / genetics
  • Promoter Regions, Genetic
  • Uncoupling Protein 2 / genetics

Substances

  • Uncoupling Protein 2
  • Ion Channels
  • Mitochondrial Proteins
  • UCP2 protein, human