Zhang Man, Liao Yalin, Lönnerdal Bo
Department of Nutrition, University of California, Davis, California.
Department of Genome Sciences, The Australian National University, Canberra, Australia.
Pediatr Res. 2016 Nov;80(5):759-765. doi: 10.1038/pr.2016.150. Epub 2016 Sep 7.
Growth factors (GFs) are milk bioactive components contributing to the regulation of neonatal small intestinal maturation, and their receptors on the small intestinal epithelium play essential roles in mediating the functions of GFs. There is limited data correlating milk GFs and their receptors in the neonatal small intestine during the perinatal period.
Small intestines of C57BL/6N mouse pups were collected at regular intervals during fetal life and up to postnatal day (PD) 60. Gene expression of GF receptors was determined by real-time qPCR. Milk GF concentrations up to PD21 were analyzed by enzyme-linked immunosorbent assay.
The majority of GF receptors showed significantly greater expression in the fetus than in postnatal life, and a sharp decrease occurred from PD14 extending to PD60; solid food restriction (PD14 and PD18) did not affect this decrease. Concentrations of five detected milk GFs demonstrated that GFs and the corresponding small intestinal receptors exhibited different correlations, with only milk transforming growth factor β1 (TGF-β1) having a significant positive correlation with TGF-β receptor 1 mRNA.
Gene expression of small intestinal GF receptors is likely a process of neonatal intestinal maturation that is affected concurrently by milk GFs and additional endogenous factors.
生长因子（GFs）是牛奶中的生物活性成分，有助于调节新生儿小肠成熟，其在小肠上皮细胞上的受体在介导生长因子的功能中起重要作用。围产期新生儿小肠中牛奶生长因子及其受体之间的相关数据有限。
在胎儿期至出生后第60天期间，定期收集C57BL/6N小鼠幼崽的小肠。通过实时定量PCR测定生长因子受体的基因表达。采用酶联免疫吸附测定法分析出生后第21天之前的牛奶生长因子浓度。
大多数生长因子受体在胎儿期的表达明显高于出生后，且从出生后第14天到第60天急剧下降；固体食物限制（出生后第14天和第18天）不影响这种下降。检测到的五种牛奶生长因子的浓度表明，生长因子与相应的小肠受体表现出不同的相关性，只有牛奶转化生长因子β1（TGF-β1）与TGF-β受体1 mRNA呈显著正相关。
小肠生长因子受体的基因表达可能是新生儿肠道成熟的一个过程，同时受到牛奶生长因子和其他内源性因素的影响。
