Perr H, Oh P, Johnson D
Department of Pediatrics, University of California, San Francisco, USA.
Gastroenterology. 1996 Jan;110(1):92-101. doi: 10.1053/gast.1996.v110.pm8536892.
BACKGROUND & AIMS: The intestinal wall is formed by smooth muscle and the regulated deposition of specific collagen types. This study is the first to examine transforming growth factor beta (TGF-beta) in human fetal intestinal muscle. Studies localized TGF-beta within the muscularis propria, identified the cellular source, measured TGF-beta, and determined effects on collagen synthesis from 10 to 21 weeks of gestation.
Localization of TGF-beta within the intestinal wall and in cultured cells was determined immunohistochemically. TGF-beta was measured by the CCL-64 cell growth inhibition assay. Collagen production was assayed as the uptake of 3H-proline into collagenase-digestible protein. Collagen types were identified by polyacrylamide slab gel electrophoresis and quantitated by densitometry. Experiments were performed in TGF-beta (50-200 pg/mL) or anti-TGF-beta (50-200 micrograms/mL).
TGF-beta 1 was localized in muscle cells of the muscularis propria and in culture. Muscle cells produced 340% more TGF-beta at 11 weeks of gestation than at 20 weeks. At 10 weeks of gestation, TGF-beta inhibited collagen production by 38%, but stimulated collagen synthesis by 70% at 21 weeks of gestation. TGF-beta altered the expression of individual collagen chains in an age-specific manner.
Smooth muscle cells secrete TGF-beta during human fetal intestinal development. TGF-beta stimulates or inhibits the expression of specific collagen chains depending on gestational age.
肠壁由平滑肌和特定类型胶原蛋白的有序沉积构成。本研究首次检测人胎儿肠肌中的转化生长因子β（TGF-β）。研究确定了妊娠10至21周期间TGF-β在固有肌层中的定位、细胞来源、TGF-β的测量以及对胶原蛋白合成的影响。
通过免疫组织化学法确定TGF-β在肠壁和培养细胞中的定位。采用CCL-64细胞生长抑制试验测量TGF-β。通过测定3H-脯氨酸掺入胶原酶可消化蛋白的量来检测胶原蛋白的产生。通过聚丙烯酰胺平板凝胶电泳鉴定胶原蛋白类型，并通过光密度法进行定量。实验分别用TGF-β（50 - 200 pg/mL）或抗TGF-β（50 - 200 μg/mL）进行。
TGF-β1定位于固有肌层的肌细胞以及培养细胞中。妊娠11周时肌细胞产生的TGF-β比20周时多340%。妊娠10周时，TGF-β抑制胶原蛋白产生38%，但在妊娠21周时刺激胶原蛋白合成70%。TGF-β以年龄特异性方式改变单个胶原链的表达。
在人胎儿肠道发育过程中，平滑肌细胞分泌TGF-β。TGF-β根据胎龄刺激或抑制特定胶原链
