E3泛素连接酶AMFR调控巨噬细胞极化介导哮喘的作用机制及潜在药靶研究

哮喘是威胁人类健康的难治性疾病，其发病机理和分子机制亟待阐明。我们前期研究发现E3泛素连接酶AMFR在哮喘病人肺泡巨噬细胞中高表达，提示AMFR参与调控哮喘。为此，我们构建了巨噬细胞特异性AMFR敲除小鼠，发现敲除小鼠哮喘性炎症损伤减弱和巨噬细胞M2型极化降低；并初步探明AMFR直接结合磷酸酶SHP-1，诱导其泛素化降解，从而增强STAT6磷酸化，促进巨噬细胞M2型极化；我们基于AMFR和SHP-1相互作用搭建药物筛选系统，获得潜在抑制剂己酮可可碱。依据坚实的前期研究结果，本项目将继续探明AMFR对于哮喘性炎症的影响和巨噬细胞M2型极化的作用；重点探讨AMFR结合降解SHP-1的分子机制，鉴定结合区域和关键分子位点；评价AMFR潜在抑制剂己酮可可碱治疗哮喘的药理机制。综上，本项目将系统阐明AMFR通过调控M2型巨噬细胞极化介导哮喘的分子病理机制，为治疗哮喘提供潜在药靶和可能性治疗药物。

Asthma is a severe disease that threatens human health. The molecular and pathological mechanisms for asthma hasn’t been completely unveiled yet. Our supporting data display that the expression of AMFR was increased in alveolar macrophages of asthmatic patients, indicating AMFR is involved in regulation of asthma. To determine whether AMFR is required for asthma, we generated macrophage specific AMFR knockout mice, which displayed the decreased asthmatic inflammation and reduced M2 macrophage polarization. Furthermore, we identified that AMFR directly interacted with SHP-1 and down-regulated the expression of SHP-1 by ubiquitin-mediated protein degradation, which in turn enhanced the phosphorylation of STAT6 and accentuated M2 macrophage polarization. Based on the interaction between AMFR and SHP-1, we made the drug screening system and found a potential inhibitor pentoxifylline. Based on our solid supporting data, we will comprehensively describe whether AMFR modulates asthma by regulating M2 macrophage polarization by 4 specific aims: (1) To determine whether AMFR is required for asthmatic inflammation; (2) To determine the necessity and sufficiency for AMFR in M2 macrophage polarization; (3) To determine how AMFR regulates the degradation of SHP-1; (4) To determine whether pentoxifylline ameliorates asthma by inhibiting the interaction between AMFR and SHP-1. All in all, our studies will not only describe the molecular pathological mechanisms that AMFR modulates asthmatic inflammation by regulating M2 macrophage polarization, but also provide a scientific basis for discovery of novel medicine for therapeutic intervention of asthma.