Hepatic insulin gene therapy normalizes diurnal fluctuation of oxidative metabolism in diabetic BB/Wor rats.
Previous studies of hepatic insulin gene therapy (HIGT) focused on glycemic effects of insulin produced from hepatocytes. In this study, we extend the observations of glycemic control with metabolically regulated HIGT to include systemic responses and whole-body metabolism. An insulin transgene was administered with an adenoviral vector [Ad/(GlRE)(3)BP1-2xfur] to livers of BB/Wor rats made diabetic with polyinosinic polycytidilic acid (poly-I:C) (HIGT group), and results compared with nondiabetic controls (non-DM), and diabetic rats receiving different doses of continuous-release insulin implants (DM-low BG and DM-high BG). Blood glucose and growth normalized in HIGT, with lower systemic insulin levels, elevated glucagon, and increased heat production compared with non-DM. Minimal regulation of systemic insulin levels were observed with HIGT, yet the animals maintained normal switching from carbohydrate to lipid metabolism determined by respiratory quotients (RQs), and tolerated 24-hour fasts without severe hypoglycemia. HIGT did not restore serum lipids as we observed increased triglycerides (TGs) and increased free fatty acids, but reduced weight of visceral fat pads despite normal total body fat content and retroperitoneal fat depots. HIGT favorably affects blood glucose, normalizes metabolic switching in diabetic rats, and reduces intra-abdominal fat deposition.
Olson
Darin E
DE
Research Service Line, Atlanta VA Medical Center, Decatur, Georgia 30033, USA.
Campbell
Adam G
AG
Porter
Marty H
MH
Freeman
Kimberly G
KG
Kelso
Emily
E
Flatt
William P
WP
Thulé
Peter M
PM
D050153:Abdominal Fat / Q000378:metabolism; D000256:Adenoviridae; D000818:Animals; D001786:Blood Glucose; D001823:Body Composition; D002940:Circadian Rhythm; D003921:Diabetes Mellitus, Experimental / Q000628:therapy*; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D007328:Insulin / Q000097:blood / Q000235:genetics*; D008099:Liver / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D011919:Rats, Inbred Strains; D014161:Transduction, Genetic; D014280:Triglycerides / Q000097:blood / Q000378:metabolism
D001786:Blood Glucose; D007328:Insulin; D014280:Triglycerides