Study On The ProNGF Apoptosis Pro-signal Mediating By Sortilin In Developmental Course Of Rat Nerve Tube Defect

[Objective]:To investigate the relationship bewteen proNGF apoptosis pro-signal mediating by Sortilin and development of rat nerve tube defect.[Methods]:3.5 to 4 months adult clear-grade rats,weighting 200～220g were taken together by female 2 and male 1 at 18:00 clock in the afternoon,and at 8:00 clock next morning,sperm blades were tested under microscope and preserved the photos. The female rats that found sperms were used as the first day of pregnancy date(E1d) animals,the later day as the rero day(E0d),the rest might be deduced by analogy.The pregnancy rats were divided into control and experimental groups randomly each group was parted to E14d,E15d,E16d,E17d,E18d,E19d,E20d and E21d groups. ten of each.Five anmals were used for the immunohistochemistry(IHC) experiment. and the other five were used for Rever Transcription Poly-merase Chain Reaction (RT-PCR) experiment.In the experimental group,after the All-trans Retinoic Acid (ATRA) was dissolved in the olive,ATRA was intragastric administrated by 50mg per kilogram in E10d peragnancy day one time.and Nerve Tube Defects(NTDs) were got. Nothing was done for the peragnancy rats in control group.In homologous time points,all the anmmals were killed and the IHC and RT-PCR were used to detect the expressional changes of Sortilin,proNGF and p75 protein and mRNA in the nerve tubes.[Results]:1,Drenching over-dose ATRA by 50mg per kilogram in the tenth days after pregnant at one time could induce the NTDs.2,Sortilin proteins expressed extensively in E14d and E15d mantle layer of control group,the positive cells were small and round.The positive reactions became stronger in E16d.deeper in alar plate than that in basal plate,and the cells were round.The positive density became weaker in E17d white matter,and many polygon positive cells appeared in iaterai nuclear groups of basal lamina,there were a lot of round positive cells in alar plate.The positive fibers were stained clearly in margina layer,but the small round ceils were little.Many positive cells were detected in E18d grey matter.Large polygon endochylema positive cells were found in the anterior horn in E19d to E21d,and the positive eonfervaceous fibers were showed more clearly in the white matter.Sortilin proteins were found in each stage of defective nerve tube in experimental group,from E14d to E19d,the positive cells were small and round.In E20d and E21d,many polygon positive cells appeared in anterior horn and round ones showed in posterior horn,positive fibers were found in white matter.The result of RT-PCR showed that proNGF mRNA could be detected in control and experimental groups,and in E21d experimental group,it was less than that in control group(P＜0.05) in the homologous time points.3,The expressional pattern of proNGF protein in normal control groups was similar to that of Sortilin's.In E14d,E15d and E16d experimental groups. proNGF protein expressed similarly to that of Sortilin protein in E14d and E15d experimental groups.In E 17d.a lot of round positive cells appeared in alar plate,and the positive fibers in marginal layer were clear.In E18d,the positive expression in hibateral posterior horns expressed differently,mainly small and round cells,and the positive in other grey matters were unclear.The expressional pattern of proNGF protein in E19d.E20d and E21d experimental groups were similar to that of Sortilin's in E20d and E21d experimental groups.RT-PCR results showed that the proNGF mRNA expressed in control and expressional groups,in E14d,E15d and E18d experimental group,it was decreased than that of control groups in the homologous time points(P＜0.05).otherwise,the expression of proNGF mRNA in E20d was less than that in.E19d experimental group.4.Expressional pattern of p75 protein in norma(?) control groups was similar to that of Sortilin's.The p75 protein expressed in E14d to E18d defective nerve tube were similar to that of Sortilin's in E14d and E15d experimental groups,in E19d and E20d.the positive reaction was weak in grey matter. In E21d,the positive reaction was weak.mainly large cells and positive fivers were clear.RT-PCR results showed that p75 mRNA expressed i(?) control and expressional groups,and in E17d expenmentai group,it was less than that in control group in homologous time points(P＜0.05).[Conelusion]:1.In the tenth day.drenching over-dose ATRA to pregnant rats by fifty per kilogram could induce NTDs.it was the best method:2 From the E14d to E21d. normal or defect nerve tubes in the development of rat,the protein and mRNA of Sortilin,proNGF and p75 were all appeared,and the proteins showed extensively in different tissues in each of the stages,otherwise,their expressional patterns were similar to each other,all of these revealed that the proNGF apoptosis pro-signal mediating by Sortilin played a very important role in the normal and defect nerve tube development course of embryo rat,and they release their biology action together.The mRNA of these factors in experimental group were weak than the control group in some time poits,revealed that RA maybe decreased the proNGF apoptosis pro-signal. and then weaker the apoptosis going-to-happen,lastly induced the defect nerve tube.