Fig. 3

Correlation of CYP2E1 protein levels, CYP2E1 gene expression and ROS, with glycemic control. a A scatter plot generated using the SigmaPlot 11.2 software, presenting measurable amounts of CYP2E1 protein in individual subjects (n = 166). Data from this scatter plot shows measurable amounts of CYP2E1 were seen even when HbA1c was 4.2 %. b CYP2E1 gene expression presented as a heat map generated using the GeneSpring 12.6 software. The heat map shows averaged CYP2E1 gene expression of study subjects who were grouped according to their HbA1c percentage. The averaged CYP2E1 gene expression for the groups of subjects who had HbA1c [(< 5.0 %); n = 8] and [(5.1–6.0); n = 20] showed down regulation and groups for subjects with HbA1c percentage [(6.1–7.0); n = 19], [(7.1–8.0); n = 11], [(8.1–9.0); n = 20], [(9.1–10.0); n = 17],[(10.1–11.0); n = 9], [(11.1–12.0); n = 6], [(12.1–13.0); n = 6] showed up-regulation. The gradual change in hues of green from dark green for group (6.1–7.0) to the lightest green in group (12.1–13.0) shows the increments in up regulation intensities of CYP2E1 gene as the HbA1c percentage increases. c CYP2E1 gene expression presented as a heat map generated using the GeneSpring 12.6 software. The heat map shows CYP2E1 gene expression for individual subjects with various HbA1c percentages. The heat map shows that CYP2E1 gene is up regulated even when HbA1c was 5.4 %, which is well within the normal reference limit for HbA1c in clinical practice. d A bar chart representing average ROS levels in the groups of subjects who had HbA1c [(< 5.0 %); n = 8],[(5.1–6.0); n = 20], [(6.1–7.0); n = 19], [(7.1–8.0); n = 11], [(8.1–9.0); n = 20], [(9.1–10.0); n = 17], [(10.1–11.0); n = 9], [(11.1–12.0); n = 6] and [(12.1–13.0); n = 6]. Error bars represent standard deviations (SD) within each group. SD was calculated using the Sigma Plot 11.2 software. Overall, the increment in ROS levels showed increment trends with increasing HbA1c percentage similar to CYP2E1 gene expression and protein amounts. This observation strongly supports the notion that the increase in ROS production during hyperglycemia induces up-regulation of CYP2E1 gene expression in peripheral lymphocytes and subsequently increases in CYP2E1 protein