大鼠前脂细胞和3T3-F442A细胞对猫血清因子的分子诱导作用的差异性反应(英文)

Differential Responsiveness of Normal Rat Preadipocytes vs. 3T3-F442A Cells to Maturation Induction by a Cat Serum Factor

根据形态学变化 ,甘油 3 磷酸脱氢酶 (GPDH)活力的升高和三酸甘油酯 (TG)积累的增加与胚牛血清(EBS)相比 ,猫血清能显著地使元代培养中大鼠前脂细胞发生分化作用 ,GPDH酶活力因加猫血清者为 :373+ 4 5单位 mg蛋白质 ,而加入FBS者为 :1 1 8+ 2 3单位 mg蛋白质 ;N =2 1 ,P <0 .0 0 1 ,相对应的TG分别为 :1 6 .1 + 2 .7μmol mgDNA与 5 .5 + 1 .2 μmol mgDNA ,N =1 2 ,P <0 .0 0 0 5。分化细胞引发的脂肪细胞转化作用 ,GPDH :FBA与胰岛素组为 1 2 4 7+ - 82单位 mg蛋白质 ,而猫血清 +FBS +胰岛素组为 1 1 4 5 + 80单位 mg蛋白质。猫血清还对大鼠前脂细胞具有促进有丝分裂的作用 ,尤其在接种后的第 4天至第 5天最为明显。此种促分化作用成分在 5 6℃经 4 5分钟后仍稳定 ,但经 1 0 0℃ 30分钟处理即遭破坏。它是非透析性的 ,对胰蛋白酶、链霉菌蛋白酶和羧肽酶A只有抗性 ,但胰凝乳蛋白酶却可使其部分地失活。它对DTT和高碘酸盐不敏感 ,在pH2和pH1 2条件下不稳定 ,其等电点为 5左右 ,它能与ConA琼脂糖相结合 ,看来是一种糖蛋白。凝胶过滤层析表明 :它的分子量为 5 7KDa。结论 :猫血清含有一种能促使元代培养中的大鼠前脂细胞转化成脂肪细胞 ,但却没有使 3T3细胞系细胞发生这种作用 ,表明这两种细胞存?

Differential responsiveness of rat preadipocytes and 3T3-F442A cells to maturation induction was studied in the presence of cat serum. As judged by morphological change and increases in glycerol-3-phosphate dehydrogenase (GPDH) activity and triacylglycerol (TG) accumulation, cat serum induced significantly differentiation of preadipocytes in primary culture as compared to fetal bovine serum (FBS) (GPDH: 373±45 vs. 118±23 U/mg protein with FBS, n=21, p<0.001; TG: 16.1±2.7 vs 5.8±1.2 μmol/mg DNA for FBS, n=12, p<0.0005). The differentiation-promoting effect is a dose -dependent fashion. In contrast, cat serum neither promoted nor inhibited appreciable adipose conversion of 3T3-F442A cells by FBS and insulin (GPDH: 1247+82 vs. 1145±80 U/mg protein with cat serum). The pronouced mitogenic effect of cat serum on rat preadipocytes was also observed, especially from day 4 to day 5 post plating. The adipogenic principle(s) is stable at 56℃ for 45 min but destroyed at 100℃ for 30 min, non-dialyzable, resistant to trypsin, pronase and carboxypeptidase A but partially inactivated by chymotrypsin, insensitive to DTT and periodate, unstable at pH 2 and pH 12 and has a pI of about 5. It is a glycoprotein binding to ConA-Argarose. Gel filtration chromatography showed that the differentiation activity corresponded to a molecular weight of 57 kDa. We conclude that there is a principle(s) in cat serum which promotes adipose conversion of rat preadipocytes in primary culture, but not for 3T3 clonal cells, and that inherent differences exist between rat preadipocytes and 3T3 cell lines.