First Author | Osanai T | Year | 2012 |
Journal | Diabetologia | Volume | 55 |
Issue | 2 | Pages | 520-9 |
PubMed ID | 22038518 | Mgi Jnum | J:181667 |
Mgi Id | MGI:5312203 | Doi | 10.1007/s00125-011-2341-z |
Citation | Osanai T, et al. (2012) Coupling factor 6-induced activation of ecto-F1F(o) complex induces insulin resistance, mild glucose intolerance and elevated blood pressure in mice. Diabetologia 55(2):520-9 |
abstractText | AIMS/HYPOTHESIS: Despite advances in pharmacological treatments, diabetes with hypertension continues to be a major public health problem with high morbidity and mortality rates. We recently identified a circulating peptide coupling factor 6 (CF6), which binds to the plasma membrane ATP synthase (ecto-F(1)F(o) complex), resulting in intracellular acidosis. We investigated whether overexpression of CF6 contributes to diabetes and hypertension by intracellular acidosis. METHODS: Transgenic mice overexpressing CF6 (also known as ATP5J) were generated, and physiological, biochemical and molecular biology studies were performed. RESULTS: CF6 overexpression elicited a sustained decrease in intracellular pH in tissues (aorta, kidney, skeletal muscle and liver, with the exception of adipose tissue) that express its receptor, the beta-subunit of ecto-F(1)F(o) complex. Consistent with the receptor distribution, phospho-insulin receptor beta, phosphoinositide 3-kinase activity and the phospho-Akt1:total Akt1 ratio were all decreased in the skeletal muscle and the liver in transgenic compared with wild-type mice, resulting in a decrease of plasma membrane-bound GLUT4 and an increase in hepatic glucose production. Under a high-sucrose diet, transgenic mice had insulin resistance and mild glucose intolerance; under a high-salt diet, they had elevated blood pressure with increased renal RAS-related C3 botulinum substrate 1 (RAC1)-GTP, which is an activator of mineralocorticoid receptor. CONCLUSIONS/INTERPRETATION: Through its action on the beta-subunit of ecto-F(1)F(o) complex, which results in intracellular acidosis, CF6 plays a crucial role in the development of insulin resistance and hypertension. This finding might advance our understanding of the mechanisms underlying diabetes and hypertension, possibly also providing a novel therapeutic target against cardiovascular disease. |