| Objective:Chronic hepatitis B virus is a kind of common infectious diseases influencing human beings’ health. Its prevention and treatment is the focus in the research on the liver diseases. However, when establishing animal models of chronic hepatitis B virus, lack of appropriate experimental animals and more "transient" infection is the main factor for hindering the establishment of animal models and further research. Some recent studies proves that tree shrews are susceptible to HBV and Sodium-taurocholic acid transit peptides (NTCP) are proved the receptor of HBV and its expression level can be regulated by some chemicals. This research is to establish NTCP overexpression models of animals and increase the susceptivity of tree shrews to HBV and further optimize chronic HBV infection models of tree shrews by exploring effective intervention means of arousing tree shrews to overexpress NTCP(sodium-Taurocholic acid transit peptides). This will provide theoretical basis for prevention and treatment schedule of further research on Chronic viral hepatitis B and some related diseases.Methods:The first part:exploring the similarities and differences of NTCP expressions of tree shrews at various ages. The number of neonatal(within 7 days) tree shrews chose n at random is 3, adolescent(from 4 to 6 weeks) 3, adult(from 4 to 6 months) 3. After doing the test by using ELISA, the concentration of NTCP are measured and their differences are compared.The second part:exploring and establishing NTCP overexpression models of tree shrews by different intervention means. Experimental group 1:adult tree shrews (six, from 4 to 6 months), feeding for four days by adding powdered cholestyramine to tree shrews’ fodder. Experimental group 2:adult tree shrews (six, from 4 to 6 months), dexamethasone intraperitoneal injection, once a day for four days. Experimental group3:adult tree shrews (six, from 4 to 6 months), combination of cholestyramine and dexamethasone, same intervention as experimental group 1 and 2. Negative control groups are set respectively for experimental group 1 and 2. Similarly, NTCP protein and gene levels are measured and their differences are compared by using ELISA and estern Blot、Real-time PCR.Results:The first part:after analysis by statistics methods, NTCP concentration on neonatal tree shrews are compared with adolescent and adult tree shrews. P<0.05 means statistics significance and there are differences between neonatal tree shrews and ado-lescent or adult tree shrews in terms of NTCP concentration. By comparing adolescent and adult tree shrews, P>0.05 means the differences between adolescent and adult tree shrews in terms of NTCP concentration are not obvious.The second part:experimental group 1 and 2 are compared respectively with their negative control groups in terms of NTCP concentration. P<0.05 means statistics significance and cholestyramine and dexamethasone have changed NTCP expression level in livers of tree shrews. The statistics analysis done on comparing experimental group 3 with 1 or 2 shows P<0.05, which means there exist some differences of NTCP expression levels between using both cholestyramine and dexamethasone and using either of them.By gathering the serum and liver sample from different periods of tree shrews and detecting NTCP concentration and doing the intra-group comparison, there is no s-tatistic significance because P>0.05 after statistic analysis.Conclusion:(1)NTCP concentration level in livers of neonatal tree shrews is lower than childhood and adult level.(2) since the childhood, the NTCP expression of tree shrews has increased to adult level, and the expression level tends to be stable.(3)Both cholestyramine and dexamethasone can increase NTCP expression levels in livers of tree shrews and the effect by using both of them is better than that by using either of them.(4)The time of drugs intervention is nothing to do with altering NTCP expression levels in livers of tree shrews... |
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