The Inhibitory Effect Of Decorin On Lymphocyte Proliferation And Immunological Rejection In Skin Transplantation

Organ transplant operation has been an effective and routine therapeutic method of End-stage organ failure. Patients must accept immunosuppressor after organ transplant operation. Immunosuppressor can decrease the incidence of acute immunologic rejection, the development of immunosuppressors promotes the development of organ transplant. About more than half a century, immunosuppressors gain significant achievement in the field of organ transplant, they proceed a tremendous step in the history of Human Sciences. In the 1960s there are seldom immunosuppressors, only Glucocorticoids and Azathioprine. Antilymphocyte Globulin came out and was applied to clinical patients in the 1970s. Cyclosporin came out in the beginning of 1980s. In the 1990s, Mycophemolate Mofeil and tacrolimus were applied to the clinics. For the past few years many new immunosuppressors came out and were used by clinical doctors, they can inhibit effectively immunologic rejection. Although these immunosuppressors have improved tremendously hepatotoxicity, renal toxicity, neurotoxicity and gastrointestinal toxicity, they still have some different and adverse reactions. There are many liver cancer patients in China, some of them must accept liver transplant operations.Decorin was indicated that it had anti-tumor function, The aim of this study was to investigate whether decorin has immunosuppressional function. A liver cancer patient must sume immunosuppressors after the liver transplant operation, these medicines can decrease immunologic rejection, meanwhile, they evoke possiblely the recurrence of liver cancer and infection. Organ transplant doctor should solve above these questions as soon as possible. If we can discover a new medicine which can overcome above deficiencies, it surely profits organ transplant doctors and patients.DCN is one of important components in extracellular matrix, it has many bioactivity. It can inhibit the proliferation of many tumor cells in a great many vitro experiments. Its inhibitory mechanism is the following:①DCN influences cell cycle, it can increase G1 phase Cell Number and decrease S phase Cell Number;②DCN inhibits TGF–βbioactivity and lessen tumor formation or metastasis;③DCN induces tumor apoptosis. Our studying teams have conformed that DCN inhibited liver cancer, Its mechanism is that it regulates cell cycle, promotes metastasis and inhibits the proliferation of liver cancer cells. There are seldom literatures about DCN in immunologic rejection. Mark Stegall reported that their team discovered the following: after rats heart transplant operations, they checked out DCN in 3, 5, 7d, they detected that DCN decreased when time extended in allogeneic graft rats, furthermore, acute rejections are obvious, while DCN didn't change in syngraft rats. This study indicates that DCN possiblely effects immunologic rejection.AIM:To study the effect of decorin on mice lymphocyte proliferation and immunological rejection in skin transplantation; To confirm whether DCN affects the changes of Th1 and Th2 cytokine. We want to confirm whether DCN can inhibit immunologic rejection.METHODS:We got out spleen lymphocyte of C57BL/6J mice, these cells were inoculated in 96 well plate, every well was added with 25μg CoA. these cells were divided into 5 groups and cultured with DCN in different concentration (0, 25, 50, 75, 100μg /L) for different time (24, 48, 72, 96 and 120 h), negative control group was only lymphcells and blank control group was only culture medium. Cell proliferation rates were studied by MTT, the rates of cell apoptosis were analyzed by Flow cytometry. The donor is 24 healthy BALB/c mice. The recipient is 30 C57BL/6J mice and they were divided into 5 groups, we transplanted full-thickness-skin through back to back from donor BALB/c to recipient C57BL/6J. Except group A, each group had been injected with DCN through abdominal cavity after operation. Corresponding dosis were:A: injected 0.9% Nacl 1ml, negative control;B:50μg DCN group;C:100μg DCN group;D:150μg DCN group. F group was skin transplantation between two C57BL/6J mice. We check out Th1 and Th2 cytokine of Peripheral blood by ELISA after 7d operation. Repeat above experiment. After we performed Skin transplantation, we observed the survival time of skin allografts and the time of acute rejection. Skin specimens were collected from one recipient of every group 7 days after operation, they were examined by pathology.RESULTS:DCN obviously depresses mice spleen lymphocyte proliferation in vitro and induces lymphocyte apoptosis in vitro, the inhibitory effect of 100μg/L group was better, the apoptosis rate was 77.6%. Statistical analysis showed that there was difference between 100μg/L group and other groups(P<0.05); We checked out cytokine in acceptor Peripheral blood after 7d operation, resulta are the following: IL-2, IFN-γand TNF-αwent down in A, B, C, D and E groups, Th1 cytokine was the highest one in A group, for example, IL-2 (45.1±1.8 pg/L), but it was the lowest one in E group, IL-2(45.1±1.8 pg/L). IL-4 and IL-10 went up in A, B, C, D and E groups, Th2 cytokine was the lowest one in A group, for example, IL-4(60.9±2.6 pg/L), but it was the highest one in E group, IL-4(88.3±1.4 pg/L). IL-6 didn't have a marked change in each group. Statistical analysis showed that there was difference about IL-2, IFN-γ, TNF-α, IL-4 and IL-10 between E group and other groups (P<0.05) and there was no difference about IL-6. We checked out cytokine in acceptor Peripheral blood after 7d operation , the results are the following: Th1 and Th2 cytokine in A, B and E groups didn't have a obvious change, IL-6 in each group also didn't have a obvious change. IL-2, IFN-γand TNF-αafter 14d operation were higher than them after 7d operation, but IL-4 and IL-10 were contrary. Statistical analysis showed that there was difference about IL-2, IFN-γ, TNF-α, IL-4 and IL-10 between 7d operation and 14d operation (P<0.05). DCN inhibits immunological rejection of skin transplantation and extends the survivaI time of skin allografts. Among all the groups, the graft of 150μg group survived for the longest time, the average survival time was(16.6±2.4)days. Statistical analysis showed that there was difference between 150μg group and other groups(P<0.05). The depressant effect of DCN was better when its dosis was more.CONCLUSION:DCN can depresses lymphocyte proliferation in vitro, Its mechanism may be induce lymphocyte apoptosis; DCN can inhibit to secrete Th1 cytokine and promote to secrete Th2 cytokine, there are dose-effect relationship, it also motivates the proportion of Th1 cytokine and Th2 cytokine to migrate Th2 cytokine; it inhibits acute immunological rejection in skin transplantation. It can extend the survival time of skin.