熊果酸对人外周血淋巴细胞细胞因子表达的影响

发布时间：2018-03-24 03:04

本文选题：熊果酸　切入点：外周血淋巴细胞　出处：《武汉大学》2005年硕士论文

【摘要】：背景及目的: 熊果酸为五环三萜类化合物,广泛存在于中草药和食品中,具有广泛的生物学活性和药理学功效,如抗肿瘤、抗炎、免疫调节和恢复造血等。在熊果酸对机体免疫功能影响的研究中,You等发现熊果酸可通过促进巨噬细胞释放TNF-α和NO从而增强细胞免疫功能。辅助性淋巴细胞(Th细胞)在机体的免疫中起着极为关键的作用,尤其是通过分泌细胞因子调节免疫功能,目前尚无熊果酸对Th细胞影响的报道。本实验旨在研究熊果酸对正常人外周血淋巴细胞分泌Th1型细胞因子(IFN-γ,和IL-2)的影响,并检测Th1型细胞因子分泌过程中MAPK的变化,对机制作初步探讨。方法: 采用密度梯度离心法分离正常人外周血单个核细胞,再用黏附法分离得到外周血淋巴细胞。实验分别用不同浓度熊果酸(5～30μM)及PHA/PMA刺激外周血淋巴细胞,采用MTT实验分析刺激24小时的淋巴细胞的增殖情况,双抗体夹心法ELISA和半定量RT-PCR分别检测Th1型细胞因子(IFN-γ和IL-2)分泌及mRNA表达的变化;Western Blot检测p38 MAPK的表达及活化水平。结果: 淋巴细胞在不同浓度熊果酸作用后,各组细胞增殖无显著差异,而Th1型细胞因子(IFN-γ和IL-2)的分泌和mRNA的表达水平均随熊果酸浓度的增加呈浓度依赖性下降(P0.05),在高浓度熊果酸作用后,p38MAPK的活化水平出现显著性降低。结论: 熊果酸在本研究浓度范围内对丝裂原活化的淋巴细胞增殖无影响,但显著抑制Th1型细胞因子的分泌和mRNA的表达,提示抑制可能是在转录和/或转录后水平发挥作用,抑制p38MAPK的活化可能是其机制之一。熊果酸和地塞米松分子结构相似,推测熊果酸可能通过类似地塞米松下调糖皮质激素受体发挥作用。熊果酸有可能用于自身免疫性疾病和超敏反应性疾病的防治。
[Abstract]:Background and purpose:
Ursolic acid is three pentacyclic triterpenoids, widely exists in Chinese herbal medicine and food, has a wide range of biological activities and pharmacological effects, such as anti-tumor, anti-inflammatory, immune regulation and hematopoietic recovery. Study the effects of ursolic acid on immune function, You found that ursolic acid can stimulate macrophages to release TNF- alpha and NO can enhance the cellular immune function. Helper lymphocytes (Th cells) in immune plays a key role, especially through the secretion of cytokines regulate the immune function, there is no reported effects of ursolic acid on Th cells. This experiment aims to study on ursolic acid in normal human peripheral blood lymphocyte Th1 cytokines (IFN-, and IL-2) the influence, and to detect changes of Th1 cytokine secretion process in MAPK, preliminary study on the mechanism.
Method:
Using density gradient centrifugation of normal human peripheral blood mononuclear cells isolated from peripheral blood lymphocytes by adhesion method. Experiments with different concentration of ursolic acid (5~30 M) and PHA/PMA stimulated peripheral blood lymphocytes, the analysis of the proliferation of lymph cells stimulated 24 hours MTT experiment, double antibody sandwich ELISA and semi quantitative RT-PCR were used to detect Th1 type cytokines (IFN- gamma and IL-2) changes in the secretion and expression of mRNA; expression of Western Blot p38 MAPK detection and activation level.
Result:
Lymphocytes in different concentration of ursolic acid. After that, there was no significant difference between the cells proliferation, and Th1 type cytokines (IFN- gamma and IL-2) expression and mRNA secretion were increased with the increase of the concentration of ursolic acid in a concentration dependent decrease (P0.05), the high concentration of ursolic acid after activation level of p38MAPK significantly decreased.
Conclusion:
No effect of ursolic acid on the activation of mitogen in this study in the concentration range of lymphocyte proliferation, secretion and expression of mRNA but inhibited Th1 type cytokines, suggesting that inhibition may be in transcriptional and / or post transcriptional levels play a role in inhibiting the activation of p38MAPK may be one of the mechanisms of ursolic acid and dexamethasone. Similar molecular structure. That ursolic acid may play a role through the down-regulation of glucocorticoid receptor is similar to dexamethasone. Ursolic acid may be used for the prevention and treatment of autoimmune diseases and allergic diseases.

【学位授予单位】：武汉大学
【学位级别】：硕士
【学位授予年份】：2005
【分类号】：R392

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