Regulation of the nitric oxide system in human adipose tissue.
Nitric oxide (NO) is involved in adipose tissue biology by influencing adipogenesis, insulin-stimulated glucose uptake, and lipolysis. The enzymes responsible for NO formation in adipose cells are endothelial NO synthase (eNOS) and inducible NO synthase (iNOS), whereas neuronal NO synthase (bNOS) is not expressed in adipocytes. We characterized the expression pattern and the influence of adipogenesis, obesity, and weight loss on genes belonging to the NO system in human subcutaneous adipose cells by combining in vivo and in vitro studies. Expression of most of the genes known to belong to the NO system (eNOS, iNOS, subunits of the soluble guanylate cyclase, and both genes encoding cGMP-dependent protein kinases) in human adipose tissue and isolated human adipocytes was detected. In vitro adipogenic differentiation increased the expression level of iNOS significantly, whereas eNOS expression levels were not influenced. The genes encoding eNOS, iNOS, and cGMP-dependent protein kinase 1 were expressed at higher levels in obese women. Expression of these genes, however, was not influenced by 5% weight loss. Insulin and angiotensin II (Ang II) increased NO production by human preadipocytes in vitro. Increased eNOS and iNOS expression in adipocytes and local effects of insulin and Ang II may increase adipose tissue production of NO in obesity.
Engeli
Stefan
S
HELIOS-Klinikum Berlin, Franz Volhard Clinic, Charite University Medicine in Berlin, Max Delbruck Center for Molecular Medicine, Berlin, Germany. engeli@fvk.charite-buch.de
Janke
Jürgen
J
Gorzelniak
Kerstin
K
Böhnke
Jana
J
Ghose
Nila
N
Lindschau
Carsten
C
Luft
Friedrich C
FC
Sharma
Arya M
AM
D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism*; D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism*; D000328:Adult; D000804:Angiotensin II / Q000494:pharmacology; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D008875:Middle Aged; D009569:Nitric Oxide / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism; D015431:Weight Loss
D007328:Insulin; D000804:Angiotensin II; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase