title: Low early B-cell factor 1 (EBF1) activity in human subcutaneous adipose tissue is linked to a pernicious metabolic profile.
abstract: OBJECTIVE
  Recently, in both human and murine white adipose tissue (WAT), transcription factor early B-cell factor 1 (EBF1) has been shown to regulate adipocyte differentiation, adipose morphology and triglyceride hydrolysis (lipolysis). This study investigated whether EBF1 expression and biological activity in WAT is related to different metabolic parameters.
  
  
  METHODS
  In this cross-sectional study of abdominal subcutaneous WAT, EBF1 protein levels were examined in 18 non-obese subjects, while biological activity was determined in 56 obese and non-obese subjects. Results were assessed by anthropometric measures and blood pressure as well as by plasma lipid levels and insulin sensitivity.
  
  
  RESULTS
  EBF1 protein levels were negatively associated with waist circumference (r=-0.56; P=0.015), but not with body mass index (BMI) or body fat (P=0.10-0.29). Biological activity of EBF1 correlated negatively with plasma triglycerides (r=-0.46; P=0.0005) and plasma insulin (r=-0.39; P=0.0027), but positively with plasma HDL cholesterol (r=0.48; P=0.0002) and insulin sensitivity, as assessed by intravenous insulin tolerance test (r=0.64; P<0.0001). These relationships, except for plasma insulin, remained statistically significant after adjusting for BMI and adipose morphology. EBF1 activity was not associated with age, systolic/diastolic blood pressure or total plasma cholesterol (P=0.17-0.48). In contrast to EBF1 activity, after adjusting for BMI, EBF1 mRNA levels displayed only an association with plasma triglycerides.
  
  
  CONCLUSIONS
  Low EBF1 protein expression and activity in abdominal subcutaneous WAT is a BMI-independent marker for several traits associated with the metabolic syndrome. However, whether EBF1 constitutes a novel treatment target remains to be demonstrated.
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, 14186 Stockholm, Sweden.
authors: P
authors: P
authors: Petrus
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, 14186 Stockholm, Sweden.
authors: N
authors: N
authors: Mejhert
authors: Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, 14186 Stockholm, Sweden.
authors: H
authors: H
authors: Gao
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, 14186 Stockholm, Sweden.
authors: J
authors: J
authors: Bäckdahl
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, 14186 Stockholm, Sweden; RIKEN Center for Life Science Technologies (Division of Genomic Technologies), RIKEN Yokohama Institute, Yokohama, 230-0045 Kanagawa, Japan.
authors: E
authors: E
authors: Arner
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, 14186 Stockholm, Sweden.
authors: P
authors: P
authors: Arner
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, 14186 Stockholm, Sweden. Electronic address: mikael.ryden@ki.se.
authors: M
authors: M
authors: Rydén
mesh_terms: D050153:Abdominal Fat / Q000737:chemistry; D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008055:Lipids / Q000097:blood; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology / Q000378:metabolism; D050151:Subcutaneous Fat / Q000737:chemistry*; D015534:Trans-Activators / Q000032:analysis*
chemical_list: C081976:EBF1 protein, human; D008055:Lipids; D015534:Trans-Activators
keywords: Diabetes; Dyslipidaemia; Insulin resistance; Obesity