Rao M, Manishen W J, Maheshwari Y, Sykes D E, Siyanova E Y, Tyner A L, Weiser M M
Department of Medicine, State University of New York at Buffalo.
Gastroenterology. 1994 Sep;107(3):764-72. doi: 10.1016/0016-5085(94)90125-2.
BACKGROUND/AIMS: Studies have identified a 67-kilodalton high-affinity laminin receptor (LR) whose expression has also been related to development, differentiation, and neoplastic transformation. The relationship of the 67-kilodalton LR to hepatic and enterocyte development and to enterocyte differentiation was investigated.
LR messenger RNA (mRNA) was identified using a complementary DNA isolated from a rat crypt cell library. LR and integrin (alpha 6, beta 1, and beta 4) expression by rat intestinal crypt cells was compared with that of the more differentiated villus cells using Northern blotting. Developmental differences in LR expression were studied in fetal and neonatal rats. The pattern of LR expression in fetal and adult rat intestines was examined further by in situ hybridization.
LR mRNA levels were highest in fetal liver and intestine and adult rat crypt cells. LR mRNA levels were 9-10 times greater in crypt than in villus cells. Integrin subunit expression differed little between crypt and villus cells. Nascent transcription studies showed that the proportion of newly transcribed LR mRNA per total RNA synthesized was similar for crypt and villus cells, suggesting posttranscriptional control of LR mRNA levels in villus cells.
Increased LR mRNA expression is a feature of the fetal intestine and of the undifferentiated, mitotically active crypt cells.
背景/目的：研究已鉴定出一种67千道尔顿的高亲和力层粘连蛋白受体（LR），其表达也与发育、分化和肿瘤转化有关。本研究探讨了67千道尔顿LR与肝脏和肠上皮细胞发育以及肠上皮细胞分化的关系。
使用从大鼠隐窝细胞文库中分离的互补DNA鉴定LR信使核糖核酸（mRNA）。采用Northern印迹法比较大鼠肠隐窝细胞与分化程度更高的绒毛细胞中LR和整合素（α6、β1和β4）的表达。研究了胎鼠和新生鼠中LR表达的发育差异。通过原位杂交进一步检测胎鼠和成年大鼠肠道中LR的表达模式。
LR mRNA水平在胎肝、肠以及成年大鼠隐窝细胞中最高。隐窝细胞中LR mRNA水平比绒毛细胞高9 - 10倍。隐窝细胞和绒毛细胞之间整合素亚基表达差异不大。新生转录研究表明，隐窝细胞和绒毛细胞中，新转录的LR mRNA占总合成RNA的比例相似，这表明绒毛细胞中LR mRNA水平存在转录后调控。
LR mRNA表达增加是胎儿肠道以及未分化、有丝分裂活跃的隐窝细胞的一个特征。
