Bernardo 2015 J Nutr Biochem
|Bernardo AF, Cortez E, Neves FA, Vieira AKG, Soares V, Rodrigues-Cunha AC, Andrade DC, Thole AA, Gabriel-Costa D, Brum PC, Moura AS, Garcia-Souza EP (2015) Overnutrition during lactation leads to impairment in insulin signaling, upregulation of GLUT1 and increased mitochondrial carbohydrate oxidation in heart of weaned mice. J Nutr Biochem 29:124-32.|
Abstract: Several studies have demonstrated that overnutrition during early postnatal period can increase the long term risk of developing obesity and cardiac disorders, yet the short-term effects of postnatal overfeeding in cardiac metabolism remains unknown. The aim of our study was to investigate the cardiac metabolism of weaned mice submitted to overnutrition during lactation, particularly as to mitochondrial function, substrate preference and insulin signaling. Postnatal overfeeding was induced by litter size reduction in mice at postnatal day 3. At 21 days of age (weaning), mice in the Overfed group (OG) presented biometric and biochemical parameters of obesity, including increased body weight, visceral fat, liver weight and increased left ventricle weight/tibia length ratio; indicating cardiac hypertrophy; hyperglycemia, hyperinsulinemia and increased liver glycogen content compared to control group (CG). In the heart, we detected impaired insulin signaling, mainly due to decreased IRβ, pTyr-IRS1, PI3K, GLUT4 and pAkt/Akt, and increased PTP1B, GLUT1 and pAMPKα/AMPKα content. Activities of lactate dehydrogenase and citrate synthase were increased, accompanied by enhanced carbohydrate oxidation, as observed by high-resolution respirometry. Moreover, OG hearts had lower CPT1, PPARα and increased UCP2 mRNA expression, associated with increased oxidative stress (4-HNE content), BAX/BCL2 ratio and cardiac fibrosis. Ultrastructural analysis of OG hearts demonstrated mild mitochondrial damage without alterations in OxPhos complexes. In conclusion, overnutrition during early life induces short term metabolic disturbances, impairment in heart insulin signaling, upregulates GLUT-1 and switch cardiac fuel preference in juvenile mice.
• Keywords: Overnutrition, Obesity, Cardiac metabolism, Mitochondrial function, Cardiac insulin signaling
• O2k-Network Lab: BR Rio de Janeiro Moura AS
Labels: MiParea: Respiration, Exercise physiology;nutrition;life style Pathology: Diabetes, Obesity
Organism: Mouse Tissue;cell: Heart Preparation: Permeabilized tissue Enzyme: Complex I, Complex II;succinate dehydrogenase, Complex III, Complex IV;cytochrome c oxidase, Complex V;ATP synthase
Coupling state: LEAK, OXPHOS Pathway: F, N, NS HRR: Oxygraph-2k