TY - JOUR
T1 - Insulin increases lipogenic enzyme activity in human adipocytes in primary culture
AU - Moustaïd, Naïma
AU - Jones, Brynn H.
AU - Taylor, James W.
PY - 1996/4
Y1 - 1996/4
N2 - Studies with human adipose tissue have demonstrated the presence of key enzymes of fat synthesis. However, long-term regulation of these enzymes has not been reported. To address this issue, we used human adipocytes in primary culture. Human adipose tissue was obtained from abdominal fat of patients undergoing abdominal surgery. Adipocytes were isolated by collagenase digestion and cultured in media supplemented with 1% fetal bovine serum. To evaluate metabolic activity of cultured cells, we assessed the following during the culture: DNA pattern, cell size, glucose consumption and activities for two lipogenic enzymes, fatty acid synthase (FAS) and glycerol- 3-phosphate dehydrogenase (GPDH). Analysis of DNA pattern showed that human adipocytes cultured under the above conditions did not undergo cell apoptosis. In addition, no significant change in the cell size occurred during 22 d of culture. Glucose consumption by cultured cells was also constant during the culture and was 60% greater in the presence of 10 nmol/L of insulin. Treatment of cultured human adipocytes with insulin for 3-22 d increased GPDH and FAS activity by 60% and 2.8-fold, respectively, compared to cells cultured without insulin. Furthermore, the increase in FAS activity due to insulin treatment was dose dependent and maximal at 10 nmol/L. Our studies show for the first time that human adipocytes can be maintained viable and metabolically active for 2-3 wk in culture. Interestingly, cultured cells remain responsive to insulin. Therefore, this system will allow further characterization of long-term regulation of lipogenesis in human adipocytes and will be useful for developing pharmacological treatments of obesity.
AB - Studies with human adipose tissue have demonstrated the presence of key enzymes of fat synthesis. However, long-term regulation of these enzymes has not been reported. To address this issue, we used human adipocytes in primary culture. Human adipose tissue was obtained from abdominal fat of patients undergoing abdominal surgery. Adipocytes were isolated by collagenase digestion and cultured in media supplemented with 1% fetal bovine serum. To evaluate metabolic activity of cultured cells, we assessed the following during the culture: DNA pattern, cell size, glucose consumption and activities for two lipogenic enzymes, fatty acid synthase (FAS) and glycerol- 3-phosphate dehydrogenase (GPDH). Analysis of DNA pattern showed that human adipocytes cultured under the above conditions did not undergo cell apoptosis. In addition, no significant change in the cell size occurred during 22 d of culture. Glucose consumption by cultured cells was also constant during the culture and was 60% greater in the presence of 10 nmol/L of insulin. Treatment of cultured human adipocytes with insulin for 3-22 d increased GPDH and FAS activity by 60% and 2.8-fold, respectively, compared to cells cultured without insulin. Furthermore, the increase in FAS activity due to insulin treatment was dose dependent and maximal at 10 nmol/L. Our studies show for the first time that human adipocytes can be maintained viable and metabolically active for 2-3 wk in culture. Interestingly, cultured cells remain responsive to insulin. Therefore, this system will allow further characterization of long-term regulation of lipogenesis in human adipocytes and will be useful for developing pharmacological treatments of obesity.
KW - fatty acid synthase
KW - glycerol-3- phosphate dehydrogenase
KW - human adipocytes
KW - insulin
KW - primary culture
UR - http://www.scopus.com/inward/record.url?scp=0029972520&partnerID=8YFLogxK
U2 - 10.1093/jn/126.4.865
DO - 10.1093/jn/126.4.865
M3 - Article
C2 - 8613889
AN - SCOPUS:0029972520
VL - 126
SP - 865
EP - 870
JO - Journal of Nutrition
JF - Journal of Nutrition
SN - 0022-3166
IS - 4
ER -