Catecholamine stimulated lipolysis in differentiated human preadipocytes in a serum‐free, defined medium

Abstract

Adipocyte precursors from the stromal vascular fraction of human adipose tissue were allowed to differentiate in serum-free defined medium, whereafter their catecholamine stimulated lipolytic response was compared to that of mature isolated human adipocytes. Seventy-five to ninety percent of the fibroblast-like cells accumulated lipid droplets and glycerol-3-phosphate dehydrogenase activities of 1,000-2,800 mU/mg protein were measured in cell homogenates of differentiated cells. Lipolysis could be stimulated by both isoproterenol and norepinephrine in both differentiated preadipocytes as well as mature adipocytes. The results obtained with beta-adrenergic agents suggested the presence of a higher affinity receptor in differentiated preadipocytes as compared to mature adipocytes. Mature adipocytes responded well to beta-adrenergic agents, but no antilipolytic alpha 2-adrenergic response was observed in the differentiated preadipocytes. The presence of Gi proteins in the differentiated preadipocytes was suggested by the antilipolytic effect of adenosine as well as the lipolytic activity generated by pertussis toxin. In conclusion, our medium supported the differentiation of a very high percentage of human preadipocytes which developed a sensitive beta-adrenergic lipolytic response but which lacked an alpha 2-adrenergic antilipolytic response.

Fat Depot–Specific Characteristics Are Retained in Strains Derived From Single Human Preadipocytes

“…Digests were filtered and centrifuged at 800g for 10 min. Digests were treated with an erythrocyte lysis buffer to enhance subsequent differentiation (30,31). Cells were plated in medium (1:1 Dulbecco's modified Eagle's medium; Ham's F12 that contained 10% bovine serum and antibiotics) at 4 ϫ 10 4 cells/cm 2 .…”

Fat depot origin affects adipogenesis in primary cultured and cloned human preadipocytes

“…Digests were filtered and centrifuged at 800 g for 10 min. The digests were treated with an erythrocyte lysis buffer to improve subsequent differentiation (20,60). The cells were then plated by using a low-serum plating medium (1:1 DMEM:Ham's F12 that contained 0.5% bovine serum and antibiotics) at a density of 4 ϫ 10 4 cells/cm 2 .…”

Abundance of two human preadipocyte subtypes with distinct capacities for replication, adipogenesis, and apoptosis varies among fat depots

“…Digests were filtered and centrifuged at 800 g for 10 min. The digests were treated with an erythrocyte lysis buffer (37,81). The cells were then plated using a low-serum plating medium [1:1 Dulbecco's modified Eagle's medium (DMEM)-Ham's F-12 that contained 0.5% bovine serum and antibiotics].…”