Breton M, Berrou E, Deudon E, Brahimi-Horn M C, Picard J
Laboratoire de Biochimie, INSERM-U. 181, Faculté de Médecine, Saint-Antoine, Paris, France.
Exp Cell Res. 1988 Jul;177(1):212-20. doi: 10.1016/0014-4827(88)90039-0.
The effect of insulin upon proteoglycan synthesis was studied in cultured smooth muscle cells from pig aorta blocked in the G0 phase by serum deprivation. Insulin enhanced [35S]sulfate incorporation into cell layer and medium-secreted proteoglycans. The increase in incorporation of the precursor was not due to a mitogenic response by smooth muscle cells to the hormone and the specific radioactivity of proteoglycans showed that the stimulation reflected a real increase in sulfated proteoglycan synthesis. Maximal stimulation was observed, for the cell layer as well as for the medium, 40 h after the addition of 1.7 x 10(-7) M insulin and reached respectively 65 and 53%. This stimulation was about 80 and 60% of the level achieved with 10% fetal calf serum for cell layer and medium-secreted proteoglycans, respectively. The half-maximal effect was attained, for both the cell layer and the medium, in the presence of 2.1 x 10(-9) M insulin. Proteoglycans secreted into the medium, in the presence of 1.7 x 10(-8) M insulin for 40 h, showed a higher proportion of complexes (24%) than those synthesized in control medium (11%) and at least 95% of the monomers from culture treated with insulin were characterized by a smaller hydrodynamic size than those synthesized by cells maintained in control medium. This decrease in the size of proteoglycans was partly due to a decrease in the size of their glycanic chains.
在通过血清剥夺使其停滞于G0期的猪主动脉平滑肌细胞中，研究了胰岛素对蛋白聚糖合成的影响。胰岛素增强了[35S]硫酸盐掺入细胞层和培养基分泌的蛋白聚糖中的量。前体掺入量的增加并非由于平滑肌细胞对该激素的促有丝分裂反应，蛋白聚糖的比放射性表明这种刺激反映了硫酸化蛋白聚糖合成的真正增加。在加入1.7×10(-7) M胰岛素后40小时，观察到细胞层和培养基中的刺激作用均达到最大值，分别为65%和53%。对于细胞层和培养基分泌的蛋白聚糖，这种刺激作用分别约为10%胎牛血清所达到水平的80%和60%。对于细胞层和培养基，在存在2.1×10(-9) M胰岛素时达到最大效应的一半。在存在1.7×10(-8) M胰岛素的情况下培养40小时后，分泌到培养基中的蛋白聚糖显示出比对照培养基中合成的蛋白聚糖更高比例的复合物（24%），并且用胰岛素处理的培养物中至少95%的单体的流体动力学尺寸小于对照培养基中细胞合成的单体。蛋白聚糖尺寸的这种减小部分是由于其糖链尺寸的减小。
