Tissue expression of DPP-IV in obesity-diabetes and modulatory effects on peptide regulation of insulin secretion

Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Aine M. McKillop, Claire L. Stevenson, Brian M. Moran, Yasser H.A. Abdel-Wahab, Peter R. Flatt Dipeptidyl peptidase type 4 (DPP-4) inhibitors represent an important class of glucose-lowering drug for type 2 diabetes. DPP-4 enzyme activity has been observed to be significantly altered in type 2 diabetes. Here, the role of DPP-4 was examined in a high fat fed (HFF) mouse model of insulin resistance. HFF mice had an increased bodyweight (p < .01), were hyperglycaemic (p < .01) and hyperinsulinaemic (p < .05). Compared to normal diet, HFF mice exhibited increased plasma DPP-4 activity (p < .01). Tissue distribution patterns in lean and HFF mice demonstrated highest levels of DPP-4 activity in lung (20–26 μmol/min/mg protein) and small intestine (13–14 μmol/min/mg protein), and lowest activity in the spleen (3.8 μmol/min/mg protein). Modulation of DPP-4 activity by high fat feeding was observed in several tissues with increases in the lung (p < .05), liver (p < .05), kidney (p < .05) and pancreas (p < .05). With a high fat diet, DPP-4 gene expression was upregulated in the liver (p < .001) and downregulated in the pancreas (p < 0.001) and small intestine (p < .001). Immunohistochemical analysis revealed increased DPP-4 immunostaining localised primarily in the pancreatic i...
Source: Peptides - Category: Biochemistry Source Type: research