Determination of genetic changes of Rev-erb beta and Rev-erb alpha genes in Type 2 diabetes mellitus by next-generation sequencing.

Abstract

The nuclear receptors Rev-erb alpha and Rev-erb beta are transcription factors that regulate the function of genes in glucose and lipid metabolism, and they also form a link between circadian rhythm and metabolism. We evaluated the variations in Rev-erb alpha and Rev-erb beta genes together with biochemical parameters as risk factors in type 2 diabetic (T2DM) patients. Molecular analyses of Rev-erb alpha and Rev-erb beta genes were performed on genomic DNA by using next-generation sequencing in 42 T2DM patients (21 obese and 21 non-obese) and 66 healthy controls. We found 26 rare mutations in the study groups, including 13 missense mutations, 9 silent mutations, 3 5'UTR variations, and a 3'UTR variation, of which 9 were novel variations (5 missense and 3 silent and 1 5'UTR). Six common variations were also found in the Rev-erb genes; Rev-erb beta Chr3:24003765 A>G, Rev-erb beta rs924403442 (Chr3:24006717) G>T, Rev-erb alpha Chr17:38253751T>C, Rev-erb alpha rs72836608 C>A, Rev-erb alpha rs2314339 C>T and Rev-erb alpha rs2102928 C>T. Of these, Rev-erb beta Chr3:24003765 A>G was a novel missense mutation (p.Q197R), while others were identified as intronic variants. T2DM patients with Rev-erb beta rs924403442 T allele had lower body surface area (BSA) than noncarriers (GG genotype) (p=0.039). Rev-erb alpha rs72836608 A allele and Rev-erb alpha rs2314339 CC genotype were associated with decreased serum HDL-cholesterol levels in T2DM patients (p=0.025 and p=0.027, respectively). In our study, different effects of Rev-erbs polymorphisms were found according to gender and presence of obesity. Rev-erb alpha rs72836608 (C>A) and rs2314339 (C>T) and Rev-erb alpha rs2102928 (C>T) were associated with low HDL-C levels in male T2DM patients. In female patients, Rev-erb alpha rs2102928 (C>T) was associated with high microalbuminuria and Rev-erb beta rs9244403442 G>T was associated with low HDL and high BSA values. In addition, Rev-erb alpha Chr17: 38,253,751 (T>C), rs72836608 (C>A), and rs2314339 (C>T) and Rev-erb beta Chr3:24003765 (A>G) were associated with increased serum GGT levels in obese T2DM patients. In non-obese patients, Rev-erbs SNPs had no effect on serum GGT levels. Our findings indicate that variations in the Rev-erb alpha and Rev-erb beta genes can affect metabolic changes in T2DM and these effects may vary depending on gender and obesity.