MiR-146a调控Langerhans细胞分化的分子机制及银屑灵干预作用研究

Psoriasis is one of the immune mediated systemic diseases. It is also called “Bai Bi” in traditional Chinese medicine. Mature langerhans cells secret IL-23, and then activate T cells, which is the most important pathogenesis of psoriasis. Our results indicate that miR-146a knock out can decrease the ratio of Langerhans cells in skin lesion of IMQ-induced psoriasis dermatitis in mice. Yinxieling is a herb formula for psoriasis based on the clinical experience of the famous veteran doctor of traditional Chinese medicine, which can inhibit the relative expression of IL-23 mRNA in mice. However, there are no research about that does Yinxieling have effects on miR-146a regulating LC differentiation..Therefore, this project is proposed on the basis of our previous results. Firstly, we try to decipher that Yinxieling decrease the ratio of LC in skin lesion from C57BL/6 mice which were induced by imiquimod. Secondly, MUTZ - 3 progenitor cells were employed to exploring the mechanism of miR-146a regulating LC differentiation and the intervention effects of Yinxieling. we focus on the regulative effect of miR-146a in LC differentiation and the target genes by knock-out or over-expression of miR-146a in TGF–β induced MUTZ-3 cells. Finally, we are exploring the intervention effects on TGF-β/PU.1/miR-146a/target genes, and then inhibiting LC differentiation, for Yinxieling, as to provide new theoretical basis for clinic therapy of Chinese medicine for psoriasis.

银屑病（Psoriasis，Ps）是一种由免疫介导的慢性皮肤疾病，中医称之为“白疪”。朗格汗氏细胞（Langerhans cells，LC）分泌的IL-23是银屑病发病过程中最重要的细胞因子之一。前期结果显示miR-146a基因敲除能降低小鼠皮损中LC的比例，名老中医验方银屑灵可抑制IL-23 的表达。但是，银屑灵干预miR-146a调控LC分化的作用及机制尚未进行研究。因此，本项目拟采用银屑灵对咪喹莫特诱导C57BL/6小鼠皮肤病变进行干预，明确银屑灵对LC比例，以及TGF-β/PU.1/miR-146a信号轴的干预作用；再用TGF-β诱导MUTZ-3始祖细胞分化为LC，研究银屑灵大鼠含药血清通过调控TGF-β/PU.1/miR-146a/靶基因信号轴，抑制LC分化的作用及机制。为中药治疗银屑病提供新依据。

研究背景：银屑病（Psoriasis，Ps）是一种由免疫介导的慢性皮肤炎症，全世界的发病率约为2-5%。皮肤中的朗格汗氏细胞（Langerhans cells，LC）是重要的抗原提呈细胞，在银屑病发病过程中起关键作用。银屑灵是我院名老中医禤国维教授临床实践多年的验方，临床用于治疗血瘀证寻常型银屑病近三十年，疗效确切。.研究内容：首先，从动物水平研究银屑灵的药效，并考察银屑灵对TGF-β/PU.1/miR-146a信号轴的干预作用；其次，通过生物信息学预测和基因敲除或过表达技术，研究 miR-146a调控LC分化的靶基因，并进行实验验证；最后采用银屑灵进行干预，明确银屑灵调控LC分化的作用靶点。为中药治疗银屑病提供新的理论依据。.研究结果及关键数据：.（1）.银屑灵能显著降低小鼠PASI评分（p<0.05），抑制皮肤增厚、炎症细胞渗出，munro’s 微囊肿产生等类似病理改变。同时银屑灵对LC迁移、成熟、抗原提呈三个环节均具有显著的抑制作用（p < 0.05）。并且能显著减低皮损中LC的比例和TGFβ的表达量（p < 0.05），但对PU.1+LC的比例无显著影响（p > 0.05）。.（2）.咪喹莫特可以诱导小鼠皮损中mir-146a高表达（p<0.01）,尤其在表皮的LC中具有显著的高表达（p<0.01）。经过靶基因预测，共得到36个交集基因，5条信号通路。其中， mir-146a通过靶基因NUMB和LFNG调控Nohch1信号。.（3）.银屑灵通过抑制mir-146a/NUMB/LFNG/Notch1（p < 0.05）信号通路，缓解小鼠类似银屑病皮肤炎症。.科学意义：本项目运用分子生物学和生物信息学技术，研究miR-146a调控LC分化的作用及机制，揭示其在银屑病发病过程的作用。银屑灵前期的研究主要集中在对角质细胞和促炎症细胞因子的作用上，本项目研究银屑灵对miR-146a调控LC分化的干预作用，可能与LC的分化与体内稳态，以及疾病的转归密切相关。对其进行进一步的研究对加深疾病的认识具有重要意义。用现代技术阐述名老中医验方银屑灵通过干预TGF-β/ miR-146a/NUMB/LFNG/Notch 1信号轴，治疗寻常型银屑病的作用机制。可为中药治疗银屑病提新的依据，同时促进名老中医经验传承。