Hepatic insulin synthesis increases in rat models of diabetes mellitus type 1 and 2 differently.

Insulin-positive (+) cells (IPCs), detected in multiple organs, are of great interest as a probable alternative to ameliorate pancreatic beta-cells dysfunction and insulin deficiency in diabetes. Liver is a potential source of IPCs due to it common embryological origin with pancreas. We previously demonstrated the presence of IPCs in the liver of healthy and diabetic rats, but detailed description and analysis of the factors, which potentially can induced ectopic hepatic expression of insulin in type 1 (T1D) and type 2 diabetes (T2D), were not performed. In present study we evaluate mass of hepatic IPCs in the rat models of T1D and T2D and discuss factors, which may stimulate it generation: glycaemia, organ injury, involving of hepatic stem/progenitor cell compartment, expression of transcription factors and inflammation. Quantity of IPCs in the liver was up by 1.7-fold in rats with T1D and 10-fold in T2D compared to non-diabetic (ND) rats. We concluded that ectopic hepatic expression of insulin gene is activated by combined action of a number of factors, with inflammation playing a decision role.

The role of cytokines and T-bet, GATA3, ROR-γt, and FOXP3 transcription factors of T cell subsets in the natural clinical progression of Type 1 Diabetes.

Th cells play an important role in pathogenesis of type 1 diabetes (T1D). Peripheral blood mononuclear cells were isolated from peripheral blood samples from newly diagnosed (ND), 1-year (1YD), and 5-year T1D (5YD) patients (n:8 of each group), 8 healthy controls (HC), and cultured for 24 h under unstimulated (US) and stimulated conditions. Cell ratios of Th1, Th2, Th17, Treg, and intracellular levels of IFN-γ, TNF-α, IL-10, TGF-ß, IL-5, IL-13, IL-17, and IL-21 cytokines were evaluated using the flow cytometry. mRNA expressions of transcription factors T-bet, GATA3, ROR-γt, and FOXP3 of these cells were determined by real-time PCR. Reduced CD4+CD25high cell ratios were detected in ND. CD4+CD25high cells were found to be reduced in ND and 1YD compared to HC under IL-2-stimulated conditions. Intracellular IFN-γ and TNF-α levels were low in all patients under US and IL-12-stimulated conditions. IL-17A and IL-21 were found to be high in patients with IL-6-stimulated conditions. Expressions of IL-10 and TGF-ß have been observed to be reduced in patients. Th1/Th2, Th17/Treg, and Th1/Treg ratios were higher in patient groups. FOXP3 and GATA3 mRNA expressions were found to be low in patients, while RORγt and T-bet mRNA levels were higher than HC. Th1, Th17, and Treg cells and their cytokines have been shown to be associated with type 1 diabetes.