1. Tehran university 2. Tehran university 3. Tehran university
Abstract
Introduction
Type 2 diabetes (t2d) is a metabolic disorder characterized by insulin resistance resulting in hyperglycemia and pancreatic β-cell failure to produce sufficient amount of insulin. t2d is the result of interaction between epigenetic factors and hereditary component. methylation of dna is one of the important regulatory epigenetic mechanisms of gene transcription.obesity induces a state of chronic low-grade inflammation, which is reflected by an increased production of pro-inflammatory cytokines .il-1β binding to interleukin 1 receptor type 1 (il1r1), via activation of nuclear factor-κb (nf-κb), induces the expression of various inflammatory cytokines and chemokines,thus leading to the attraction of immune cells to the islets.chronic subclinical inflammation, mediated by cytokines, may be associated with insulin resistance and the development of t2d
Methods
Eighteen t2d patients and 18 healthy controls entered in this case-control study. pbmcs were isolated from whole blood with pbs and lympholyte-h . rnx-plus guanidine-based solution and trizol protocol were used for dna extraction. dna was treated with proteinase k and digested with restriction enzymes. denatured dna incubated for 4-16hrs at 50°c with bisulfite.. pcr products of bisulfite-treated dna were sequenced to determine the methylation level of il1r1 gene promoter and statistical analysis was performed using "prism7"
Results
The results of this study showed, increased promoter methylation levels of il1r1-cpg3 gene were identified in t2d patients compared with healthy controls(p value ≤0.005 ). in addition, hemoglobin a1c (a1c) levels were positively correlated with il-1r1 promoter methylation and fasting plasma glucose (fpg) levels
Conclusion
The observed changes in il-1r1 promoter methylation levels in pbmcs may contribute to the development of inflammatory processes involved in the pathogenesis of t2d. hypermethylation of cpg3 at il1r1 in individuals with hyperglycemia may indicate an attempt to reduce the pro-inflammatory effects of il-1β via auto-stimulation. although, the role of innate immune cells in diet- and obesity induced inflammation associated with the disease has been extensively studied, less is known about the alterations and contribution of the adaptive immune cells to the pathogenesis of t2d.
