| Objective: The present study was conducted to observe the expression in the tune course and spatial distribution of protooncogene c-Jun, anti-oncogene wtp53, the gene of endogenous liver fatty acid binding protein and p38, p21 in small intestine epithelium during the developmental phase of rats. Also we investigated the biology influence of their network regulated mechanism in transcription, translation level on the differentiation and proliferation of epithelial stem cells in small intestine, which will give a hand on investigation to adult stem cells in vitro in the aspect of embryogenesis.Material and methods: 41 Wistar rats were randomly divided into ten groups as follows: (1) normal control groups (n=5); (2) the rests were divided into nine groups according to the ratio of 3 female rats and 1 male rat. The day was calculated as cyesis zero day when female rats appeared colp-lock. were killed and five embryo rats from difference fertilized rats at embryo 14day, 17day, 10 day were obtained, respectively. Five newly rats at postnatal 1,2, 3, 7, 14, 28 day and five adult rats were killed. The length 2-3 cm of small intestines obtained from each groups was removed to 4% paraformaldehyde for 2 hours, and the rests hi liquid nitrogen. In situ hybridization was used to detect 1-fabp mRNA and reverse transcription polymerase chain reaction (RT-PCR) was used to detected 1-fabp, wtp53 and p21 mRNA. Strreptavidin/peroxidase (SP) immunohistochemistry method was used to localize the protein expression of wtp53, p21, c-Jun, p38. The experimental results were analyzed by computer scanning.Results: Morpholog showed through HE stain: epithelial cellular form, quantity of villi and crypts were significant difference at the differenced developmental stages. There were no villi and crypts at embryo 14 day in bowel chamber, and epithelial cells whose nucleus were bigger, chromatin sparse, which appeared to be infantilism and the array of epithelial cells appeared to be honeycomb appearance. Immature epithelial cells in mucous membrane began to be inferior fovea , to form micro-villi when epithelial cells were immature at E17 day. Villi began to form and gradually turned into high villi and no crypts from E19d to P1d; the form of mucous membrane in intestine became mature, and there were integrity crypts at P28d.The expression of difference genes at each developmental stage in intestine was as follows;C-Jun: the ratio of positive cells at mucous membrane in intestine was 98% during the embryo 14 to 19 day, 90%, 90%, 55%, 51%, 26% at Pld, P2d, P7d, P14d, P28d, respectively. With the intestinal development increasing mature, quantity of positive cells was reducing along the ax-villi down to up, and the positive cells were only limited to the top of villi at the period of mature.P38: the ratio of positive cells at mucous membrane was very low at each developmental phase in intestine, and only localized at the interspace between villi during postnatal phase, localized in the crypts during mature phase, which were karyokinesising. The ratio of positive cells was 3%(E14d), 4%(E17d), 7%(E19d), 8%(P1d), 9%(P2d), 6%(P3d), 6%(P7d), 4%(P28d), 2%(mature), respectively.Wtp53: the positive signal of wtp53 could be detected from E17d during intestinal development. The range of positive cells distribution became widen and the positive intensity was obviously higher at P2d than another. Withintestinal development, the positive ratio of wtp53 expression increasinglyreduced. No positive signal was detected at P28d. IN the other hand, wtp53 mRNA level in intestine had no change from embryo to mature phase.P21: the expression of p21 and mRNA level could not be detected from embryo to mature phase.L-fabp mRNA: the 1-fabp mRNA level was detected by RT-PCR method at E19d, and the 1-fabp mRNA level was significantly enhanced at P2d. The change of the 1-fabp mRNA level from P3d to the mature was not obvious.L-fabp mRNA hybridization in situ: the positive cells just appeared and only localized at the top of newl...
|
PDF Full Text Request