补体抑制剂柴胡多糖对狼疮小鼠的防治作用的机制研究

Systemic lupus erythematosus (SLE) is an autoimmune disease with heterogeneous presentation and clinical manifestations. These aspects represent a problem in the treatment of the disease. Nonspecific medications for SLE that include antimalarials, corticosteroids, and cytotoxic drugs improve the prognosis of SLE yet carry significant side effects. Therefore, new targeted therapies that block pathways involved in the pathogenesis of SLE need to be developed as possible additions to the standard management of the disease. .Our previous experiments had confirme that polysaccharide isolated from Bupleurum smithii var. parvifolium （BPs) had inhibitory properties toward aberrant activation of complement and macrophages. BPs could be a benefit for slowing down the renal damage in lupus mice with reduced autoantibodies production that might related with the improving of the abnormality in immune systems..Aberrant activation of the complement and the monocytes/macrophages system is heavily involved in the frequency and functional activity of the T cell subpopulations that play a dynamic role in the initiation and perpetuation of the systemic autoimmune, result in the altered immune tolerance and organ damage..The aim of this study was to evaluate the protective effect of BPs on two kinds of models for SLE in mice. The study was to address two major issues, as follows: 1) What is the potential impact of BPs on aberrant activation of complement and the monocytes/macrophages system in lupus mice? 2) What is the effect on T cell subpopulations immune responses?.The realization of the mechanism of BPs will coincidence with the theory of traditional Chinese medicine: 'supporting healthy energy to eliminate evils' ..This work proposed some potential suggestions for future research and the direction of the investigation. The established reseaching stage will help new drug discovery by screening from traditional Chinese medicinal materials.

系统性红斑狼疮(SLE)治疗以细胞毒药物和免疫抑制剂为主,抑制补体和免疫调节是抗SLE新药研究热点。补体过度激活和单核/巨噬细胞功能异常是导致Th各亚群格局改变和调节功能丧失的重要原因,并最终导致SLE的形成；我们的研究发现,柴胡多糖抑制补体过度激活;调节单核/巨噬细胞功能;并能防治小鼠SLE,长期给药无明显的毒副作用。本研究拟采用自发型(MRL/lpr)和诱导型(空弯菌)两种SLE模型,重点观察柴胡多糖抑制补体过度激活、调节单核/巨噬细胞多项功能异常(吞噬、分泌、趋化和递呈)的作用,明确单核/巨噬细胞的TLR-4信号系统在其中的作用；其结果影响Th各亚群格局和调节功能(诱导Th2亚群向Th1移动,减少Th17亚群的功能或上调Treg亚群功能),并由此发挥疗效。明确柴胡多糖的作用机制,与中医药扶正祛邪治疗SLE的理念相吻合,为在中药材中筛选其他有类似作用的提取物提供新思路、研究方向和平台。

SLE存在单核-巨噬细胞系统功能功能异常。我们首次发现柴胡多糖（BPs）对单核-巨噬细胞的TLR-4 /TLR-2信号通路具有调节作用。BPs的离体和整体抗炎作用与其对TLR-4/2 信号通路的调节作用相关。BPs对巨噬细胞多项功能(吞噬、分泌、趋化和递呈)都具有调节的作用BPs通过调控TLR-4/TLR-2通路，改善自发型(MRL/lpr)SLE小鼠的肾损伤。.SLE存在补体系统过度激活。我们建立了筛选补体抑制剂的ELISA法，对补体的三条激活通路都可进行检测。弥补了以往补体甘露糖激活途径检测方法的缺乏。首次证实BPs对甘露糖补体活化途径有抑制作用。BPs对三条激活通路：经典、替代和甘露糖补体活化途径均有抑制作用，但不同通路的抑制效应有一定的差异。BPs通过降低抗自身抗体水平和抑制抗体-补体在肾脏的沉积，抑制了内源性激活TLR-4/TLR-2通路的HMGB-1的释放，从而抑制SLE小鼠肾炎性损伤。.辅助性T （Th）各亚群通过分泌相关细胞因子, 促进抗自身抗体的产生，参与狼疮的发生发展。Th中, Th1 介导干扰素-γ (IFN-γ) 的分泌, Th2 和调节性T （Treg）细胞介导白细胞介素-10 (IL-10) 的分泌, Th17 介导IL-17的分泌。BPs对淋巴细胞功能异常有调节作用，下调Th1、Th2 和Treg 的异常分泌功能, 抑制异常表达的抗自身抗体， 但对Th17 亚群分泌的IL-17 没有明显影响。.我们建立了离体抗炎中药筛选平台。通过优化多粘菌素预处理条件，有效地去除内毒素，减少多糖携带的内毒素对研究的干扰，保证了结果的可靠性，在清热解毒中药中筛选到多种具有抗炎作用多糖。并对其中紫草和鱼腥草多糖进行了离体和整体研究，证实了该研究平台的可靠性。.BPs减少了狼疮小鼠的肾损伤。由此，我们开展了BPs的肾保护研究。结果显示，BPs对糖尿病肾病小鼠也有保护作用。该研究获得2017国自然再次支持。.综上所述，补体过度激活和单核-巨噬细胞功能异常，是重要的SLE发病机制。BPs通过抑制补体过度激活和调节单核-巨噬细胞功能，影响Th亚群格局和调节功能，抑制了异常表达的抗自身抗体，减少了狼疮小鼠损伤。本研究明确了BPs的作用机制,与中医药扶正祛邪治疗SLE的理念相吻合,建立了从中草药中筛选其他有类似作用的药物的研究平台。