RESUMO
Obesity is increasing in prevalence and has become a global public health problem. The main cause of obesity is a perturbation in energy homeostasis, whereby energy intake exceeds energy expenditure. Although mitochondrial dysfunction has been linked to the deregulation of energy homeostasis, the precise mechanism is poorly understood. Here, we identify mitochondrial p32 (also known as C1QBP) as an important regulator of lipid homeostasis that regulates both aerobic and anaerobic energy metabolism. We show that while whole-body deletion of the p32 results in an embryonic lethal phenotype, mice heterozygous for p32 are resistant to age- and high-fat diet-induced ailments, including obesity, hyperglycemia, and hepatosteatosis. Notably, p32 +/- mice are apparently healthy, demonstrate an increased lean-to-fat ratio, and show dramatically improved insulin sensitivity despite prolonged high-fat diet feeding. The p32 +/- mice show increased oxygen consumption and heat production, indicating that they expend more energy. Our analysis revealed that haploinsufficiency for p32 impairs glucose oxidation, which results in a compensatory increase in fatty acid oxidation and glycolysis. These metabolic alterations increase both aerobic and anaerobic energy expenditure. Collectively, our data show that p32 plays a critical role in energy homeostasis and represents a potential novel target for the development of anti-obesity drugs.
Assuntos
Metabolismo Energético/genética , Hiperglicemia/genética , Proteínas Mitocondriais/genética , Obesidade/genética , Animais , Dieta Hiperlipídica/efeitos adversos , Ingestão de Energia/genética , Glicólise/genética , Heterozigoto , Homeostase/genética , Hiperglicemia/etiologia , Hiperglicemia/metabolismo , Resistência à Insulina/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Mitocondriais/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Consumo de Oxigênio/genéticaRESUMO
Globally, morbidity and mortality due to cancer are predicted to increase in both men and women in the coming decades. Furthermore, it is estimated that two thirds of these cancer-related deaths will occur in low-and middle-income countries (LMIC). In addition to morbidity and mortality, cancer also causes an enormous economic burden, especially in developing countries. There are several treatment and management options for cancer including chemotherapy, radiation therapy, surgery, and palliative care. Radiotherapy or radiation therapy (RT) can be an effective treatment, especially for localized or solid cancers; about half of cancer patients receive radiation as a curative or palliative treatment. Because of its low cost, for patients from LMIC with inoperable tumors, RT may be the only option. With the overall increase in the number of cancer patients especially in resource-starved LMIC, the need for more RT facilities further affects the economic growth of those countries. Therefore, an advanced molecular-targeted and more integrated approach involving either RT alone or with surgery and improved cancer drug access worldwide are urgent needs for cancer care.