Secretion of adiponectin multimeric complexes from adipose tissue explants is not modified by very low calorie diet.
OBJECTIVE
Adiponectin is a protein abundantly secreted by the adipose tissue (AT). Plasma adiponectin levels are decreased in obese, insulin-resistant, and type 2 diabetic patients. Various multimeric complexes, i.e. high-, middle-, and low-molecular weight isoforms (HMW, MMW and LMW), are present in plasma. Here, we investigated the effect of weight reducing diet on the distribution of adiponectin isoforms in plasma and on their secretion in AT explants from obese subjects.


METHODS
A total of 20 obese subjects (age 37.8+/-7.3 years, body mass index 33.9+/-5.0 kg/m(2)) underwent eight weeks of very low-calorie diet (VLCD). A needle biopsy of subcutaneous abdominal AT and blood samples were taken before and after dietary intervention. AT explants were incubated in culture medium for 4 h. ELISA assay and western blot analyses were used to identify adiponectin complexes in culture media and in plasma.


RESULTS
The distribution of adiponectin polymers in plasma was different from that secreted in human AT explants. Before VLCD, the relative amount of HMW isoform was 75.5+/-9.1% of total adiponectin in culture media and 52.2+/-11.2% in plasma. Despite the diet-induced weight loss and improvement of insulin sensitivity, VLCD neither induced change in total adiponectin level nor in the ratio of HMW to total adiponectin in plasma and in culture media of AT explants.


CONCLUSIONS
The profile of adiponectin polymeric isoforms secreted by AT explants into culture media differs from the plasma profile. A dietary intervention leading to weight loss and improvement of insulin sensitivity was not associated with modifications of AT secretion of total or HMW adiponectin.
Kovacova
Zuzana
Z
Sports Medicine Department, Division of Cell and Molecular Biology, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic. zuzana.kovacova@post.lf3.cuni.cz
Vitkova
Michaela
M
Kovacikova
Michaela
M
Klimcakova
Eva
E
Bajzova
Magda
M
Hnevkovska
Zuzana
Z
Rossmeislova
Lenka
L
Stich
Vladimir
V
Langin
Dominique
D
Polak
Jan
J
D052242:Adiponectin / Q000737:chemistry / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001707:Biopsy, Needle; D015153:Blotting, Western; D001827:Body Height / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D031204:Caloric Restriction; D003470:Culture Media; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007700:Kinetics; D049449:Luminescence; D008297:Male; D008970:Molecular Weight; D009765:Obesity / Q000178:diet therapy / Q000378:metabolism; D011108:Polymers / Q000737:chemistry / Q000378:metabolism; D046509:Tissue Culture Techniques; D049629:Waist-Hip Ratio; D015431:Weight Loss / Q000502:physiology
D052242:Adiponectin; D003470:Culture Media; D011108:Polymers