Human SGBS cells - a unique tool for studies of human fat cell biology

Abstract

The human Simpson-Golabi-Behmel syndrome (SGBS) preadipocyte cell strain provides a unique and useful tool for studies of human adipocyte biology. The cells originate from an adipose tissue specimen of a patient with SGBS. They are neither transformed nor immortalized, and provide an almost unlimited source due to their ability to proliferate for up to 50 generations with retained capacity for adipogenic differentiation. So far, the cells have been used for a number of studies on adipose differentiation, adipocyte glucose uptake, lipolysis, apoptosis, regulation of expression of adipokines, and protein translocation. The cells are efficiently differentiated in the presence of PPARgammaagonists and in the absence of serum and albumin. SGBS adipocytes respond to insulin stimulation by increasing glucose uptake several-fold (EC50 approximately 100 pmol/l), and by very effectively inhibiting (IC50 approximately 10 pmol/l) catecholamine-stimulated lipolysis.

Fig. 1

Optimal differentiation protocol for human SGBS cells. Differentiation is started (day 0) by incubating cells in a serum-free differentiation medium (2 µmol/l rosiglitazone, 25 nmol/l dexamethasone, 0.5 mmol/l methylisobuthylxantine, 0.1 µmol/l cortisol, 0.01 mg/ml transferrin, 0.2 nmol/l triiodotyronin, and 20 nmol/l human insulin). After 4 days, medium is changed, and cells are further cultured in medium supplemented with 0.1 µmol/l cortisol, 0.01 mg/ml transferrin, 0.2 nmol/l triiodotyronin, and 20 nmol/l human insulin.

Fig. 2

Adipogenic differentiation of SGBS cells. A Microphotographs of SGBS cells during adipose differentiation cultured according to the differentiation protocol. Intracellular lipid droplets are clearly visible on culture day 7. On culture day 14, the cells are filled with high amounts of intracellular lipids. B Markers of adipocyte differentiation and function (mRNA expression of PPARγ, Glut-4, aP2, leptin, adiponectin) are induced and further up-regulated during the differentiation process. One representative experiment out of 3 performed is shown.

Fig. 3

PPARγ-dependent differentiation and insulin-stimulated glucose uptake. A Stimulation with rosiglitazone: intracellular accumulation of triglycerides. B Glucose uptake is increase several-fold upon insulin stimulation.

Fig. 4

Glycerol (A, B) and fatty acid mobilization (C, D) from SGBS adipocytes in response to different combinations of isoproterenol and insulin. (A, C) dose-response curves for isoproterenol at fixed insulin concentrations. (B, D) dose-response curves for the inhibitory effect of insulin at fixed isoproterenol concentrations.