Investigation of hyperglycemia mediated inflammation on risk of cardiovascular disease in type 2-diabetes
Dr. Shaper Mirza (LUMS) and Dr. Bilal Bin Younas (SIHS)
The collaboration between Dr. Bilal and Dr. Shaper is part of a ground-breaking research that aims to:
- equip Diagnia, a smartphone application developed by the Biomedical Informatics Research Laboratory (BIRL) at the Lahore University of Management Sciences (LUMS), with real-world data to assist in clinical investigation of patients suffering from diabetes by precisely predicting the probability of the disease and
- study the effect of Hyperglycemia in upregulation of NFKB in Diabetics and non-Diabetics.
Type 2-diabetes and its associated chronic low-grade inflammation is partially attributed to increased levels of blood glucose or hyperglycemia. Effect of hyperglycemia on inflammation is poorly understood. Therefore the goal of this project was to determine how hyperglycemia induced inflammation.
We hypothesize that hyperglycemia either induce epigenetic changes or posttranslational modifications in genes regulating pro-inflammatory cytokines, resulting in elevated levels of cytokines and subsequent low-grade inflammation.
The hypothesis was tested by the following two aims:
(i) determine if hyperglycemia modulates posttranslational modification of p65 subunit of NF-kb, a master regulator of proinflammatory cytokines, thus activating the protein and its facilitating its mobilization into nucleus,
(ii) determine if persistent hyperglycemia causes epigenetic changes in RelA gene that encodes for p65 subunit of NF-kB.
To assess the effects of hyperglycemia, we incubated neutrophils isolated from healthy controls with increasing concentrations of glucose for four hours. Results of our studies demonstrated that NF-kB was activated and translocated into nucleus by phosphorylation of p65 subunit. Phosphorylation of NF-kB was found to be dependent on hyperglycemia mediated oxidative stress, where blocking ROS production, under hyperglycemic conditions led to decrease in phosphorylation and decrease in translocation of NF-kB into nuclear. We observed no changes in levels of methylation or RNA levels were observed when neutrophils were incubated with glucose. Neutrophils isolated from those with poorly controlled and well controlled type 2-diabetes indicated phosphorylation and translocation of RelA/p65 subunit of NF-kB. Additionally we also observed hypomethylation of the RelA gene. These contrasting results suggested that persistent hyperglycemia as observed in those with poorly controlled diabetes would result in epigenetic changes in the gene which together with posttranslational modifications would result in modulating the activity of NF-kB gene leading to chronic low-grade inflammation.
In conclusion our preliminary studies were able to demonstrate epigenetic changes in the RelA gene, which is impacting activation of NF-kB in hyperglycemic conditions. The next step will be measuring the level of proinflammatory cytokines that we hypothesize would be upregulated in response to methylation and subsequent translocation of NF-kB gene. Our future studies will be focused on identifying and measuring a range of biomarkers, which include both biochemical and molecular components in serum to develop a signature that can be used toward prediction of cardiovascular disease in those with poorly controlled diabetes.