Richardson R L, Hausman G J, Wright J T
USDA, ARS, R. B. Russell Agricultural Research Center, Animal Physiology Research Unit, Athens, GA 30604-5677, USA.
Growth Dev Aging. 1998 Spring-Summer;62(1-2):3-12.
The influence of anti-IGF-1 and anti-transforming growth factor beta (TGF-beta) neutralizing antibodies on preadipocyte differentiation and secretion of IGFBPs was examined in serum free porcine stromal-vascular cultures. Cultures were stained for morphological analysis and conditioned media were collected for: TGF-beta determination by ELISA, IGF-1 by RIA, and IGFBP analysis by ligand blotting. After 6 d of treatment, anti-TGF-beta increased fat proportions by 2.7 fold compared to controls. Anti-IGF-1 decreased fat cell proportions by 14-fold. Anti-TGF-beta increased concentrations of IGF-1 5.8-fold and IGFBP-2 and IGFBP-3 by 8- and 7-fold in conditioned media whereas IGFBP-4 decreased 5-fold. Anti-IGF-1 increased concentrations of IGFBP-2 and 3 by 9- and 35-fold, respectively. TGF-beta increased concentrations of IGFBP-1, 2 and 3 by 3-fold, 18-fold and 3-fold, respectively, after 9 d in culture (6 d of treatment). There was no change in TGF-beta levels in anti-IGF-1 treated cultures compared to controls. Control antibodies and negative controls had no effect. These results provide evidence that endogenously produced IGF-1 and TGF-beta has a major influence on preadipocyte differentiation in serum free media by modulating IGFBP production/secretion.
在无血清猪基质血管培养物中，研究了抗胰岛素样生长因子-1（IGF-1）中和抗体及抗转化生长因子β（TGF-β）中和抗体对前脂肪细胞分化和胰岛素样生长因子结合蛋白（IGFBPs）分泌的影响。对培养物进行染色以进行形态学分析，并收集条件培养基用于：通过酶联免疫吸附测定（ELISA）测定TGF-β，通过放射免疫分析（RIA）测定IGF-1，以及通过配体印迹法分析IGFBP。处理6天后，与对照组相比，抗TGF-β使脂肪比例增加了2.7倍。抗IGF-1使脂肪细胞比例降低了14倍。抗TGF-β使条件培养基中IGF-1的浓度增加了5.8倍，IGFBP-2和IGFBP-3的浓度分别增加了8倍和7倍，而IGFBP-4降低了5倍。抗IGF-1使IGFBP-2和IGFBP-3的浓度分别增加了9倍和35倍。培养9天（处理6天）后，TGF-β使IGFBP-1、IGFBP-2和IGFBP-3的浓度分别增加了3倍、18倍和3倍。与对照组相比，抗IGF-1处理的培养物中TGF-β水平没有变化。对照抗体和阴性对照没有影响。这些结果表明，内源性产生的IGF-1和TGF-β通过调节IGFBP的产生/分泌，对无血清培养基中的前脂肪细胞分化有重大影响。
