Clock genes are implicated in the human metabolic syndrome

• Published in: International Journal of Obesity 2008-01, Vol.32 (1), p.121-128
• Main Authors: Gómez-Abellán, P, Hernández-Morante, J J, Luján, J A, Madrid, J A, Garaulet, M
• Format: Article
• Language: English
• Subjects: Abdomen; Adipose tissue; Adipose tissues; Adult; Analysis; ARNTL Transcription Factors; Basic Helix-Loop-Helix Transcription Factors - genetics; Biological and medical sciences; Biological Clocks - genetics; Biopsy; Body fat; Cholesterol; Circadian rhythm; Cryptochromes; Diabetes; Epidemiology; Feedback; Flavoproteins - genetics; Gastrointestinal surgery; Gene expression; Gene Expression Regulation; Genetic aspects; Health Promotion and Disease Prevention; Health risks; Homeostasis; Humans; Insulin resistance; Internal Medicine; Intra-Abdominal Fat - physiopathology; Laparoscopy; Male; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Metabolic disorders; Metabolic syndrome; Metabolic Syndrome - genetics; Metabolic Syndrome - physiopathology; Metabolic syndrome X; Middle Aged; Miscellaneous; Nuclear Proteins - genetics; Obesity; Obesity, Morbid - genetics; Obesity, Morbid - physiopathology; original-article; Other metabolic disorders; Period Circadian Proteins; Physiology; Public Health; Reverse Transcriptase Polymerase Chain Reaction; Risk factors; RNA, Messenger - genetics; Subcutaneous Fat, Abdominal - physiopathology; Transcription Factors - genetics
• ISSN: 0307-0565; 1476-5497
• DOI: 10.1038/sj.ijo.0803689

Background: Clock genes play a role in adipose tissue (AT) in animal experimental models. However, it remains to be elucidated whether these genes are expressed in human AT. Objective: We investigated the expression of several clock genes, Bmal1 , Per2 and Cry1 , in human AT from visceral and subcutaneous abdominal depots. A second objective was to elucidate whether these clock genes expressions were related to the metabolic syndrome features. Methods: Visceral and subcutaneous AT samples were obtained from morbid obese men ( n =8), age: 42±13 years and body mass index⩾40 kg/m 2 , undergoing laparoscopic surgery due to obesity. Biopsies were taken as paired samples at the beginning of the surgical process (1100 hour). Metabolic syndrome features such as waist circumference, plasma glucose, triglycerides, total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein (LDL) cholesterol were also studied. Homeostasis model assessment index of insulin resistance was also calculated. The expression of the different clock genes, hBmal1 , hPer2 and hCry1 , was determined by quantitative real-time PCR. Results: Clock genes were expressed in both human AT depots. hBmal1 expression was significantly lower than hPer2 and hCry1 in both AT ( P