Year: 2011
Type: article
Abstract: OBJECTIVE: Macrophage recruitment to adipose tissue is a reproducible feature of obesity. However, the events that result in chemokine production and macrophage recruitment to adipose tissue during states of energetic excess are not clear. Sirtuin 1 (SirT1) is an essential nutrient-sensing histone deacetylase, which is increased by caloric restriction and reduced by overfeeding. We discovered that SirT1 depletion causes anorexia by stimulating production of inflammatory factors in white adipose tissue and thus posit that decreases in SirT1 link overnutrition and adipose tissue inflammation. RESEARCH DESIGN AND METHODS: We used antisense oligonucleotides to reduce SirT1 to levels similar to those seen during overnutrition and studied SirT1-overexpressing transgenic mice and fat-specific SirT1 knockout animals. Finally, we analyzed subcutaneous adipose tissue biopsies from two independent cohorts of human subjects. RESULTS: We found that inducible or genetic reduction of SirT1 in vivo causes macrophage recruitment to adipose tissue, whereas overexpression of SirT1 prevents adipose tissue macrophage accumulation caused by chronic high-fat feeding. We also found that SirT1 expression in human subcutaneous fat is inversely related to adipose tissue macrophage infiltration. CONCLUSIONS: Reduction of adipose tissue SirT1 expression, which leads to histone hyperacetylation and ectopic inflammatory gene expression, is identified as a key regulatory component of macrophage influx into adipose tissue during overnutrition in rodents and humans. Our results suggest that SirT1 regulates adipose tissue inflammation by controlling the gain of proinflammatory transcription in response to inducers such as fatty acids, hypoxia, and endoplasmic reticulum stress.
Source: Diabetes
DOI: 10.2337/db11-0616
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Funders: American Diabetes Association, Yale University, National Institutes of Health, U.S. Public Health Service, National Institute of General Medical Sciences, National Institute of Diabetes and Digestive and Kidney Diseases, National Institute of Biomedical Imaging and Bioengineering, National Center for Research Resources, Eunice Kennedy Shriver National Institute of Child Health and Human Development
Awards: G1216600262, G1236451951, G1248990499, G15181057, G1582702618, G1851815138, G2630622763, G2842009580, G3194548547, G362750040, Mechanisms of Lipid-Induced Hepatic Insulin Resistance, G4144142245, G453267231, G4731839318, G584496469, G66353979, Center for Reproductive Science and Medicine, Medical Scientist Training Program, Pathophysiology of Metabolic Defects of Juvenile Obesity, G9000010118, G9000032419, G9000083535, G9000192000, G9000329287, G977113172
OpenAlex ID: W2109194972