■麻风病是由麻风分枝杆菌引起的慢性传染病,会导致神经退行性疾病.麻风分枝杆菌优先感染周围神经系统的皮肤巨噬细胞和雪旺细胞-神经胶质细胞。感染改变了宿主细胞的脂质代谢,颠覆它,有利于形成富含胆固醇的脂滴(LD),这是细菌生存所必需的。尽管研究人员在了解麻风病发病机制方面取得了进展,宿主-病原体相互作用的分子和细胞机制的许多方面仍然需要澄清。嘌呤能系统利用细胞外ATP和腺苷作为关键信号分子,并在病理生理过程中发挥多种作用。此外,核苷表面受体如腺苷受体A2AR参与神经免疫反应,脂质代谢,和神经元-神经胶质相互作用是治疗不同疾病的目标。尽管这个系统很重要,没有描述过它在麻风病中的作用,特别是在麻风分枝杆菌-雪旺氏细胞相互作用期间的腺苷能信号(AdoS)。
■M.从无胸腺nu/nu小鼠的后足垫中纯化麻风。在存在或不存在AdoS的特异性激动剂或拮抗剂的情况下,用麻风分枝杆菌感染ST88-14人细胞。酶活性测定,荧光显微镜,西方印迹,进行RT-qPCR分析。通过RT-qPCR研究了麻风分枝杆菌的活力,和细胞因子通过酶联免疫吸附试验进行评估。
■我们证明了麻风分枝杆菌感染的雪旺氏细胞上调CD73和ADA,并下调A2AR表达和转录因子CREB(p-CREB)的磷酸化。另一方面,用其选择性激动剂激活A2AR,CGS21680导致:1)减少的脂滴积累和促脂肪生成基因表达;2)减少的IL-6和IL-8的产生;3)减少的细胞内麻风分枝杆菌活力;4)增加的p-CREB水平。
■这些发现表明AdoS参与麻风神经发病机制,并支持麻风分枝杆菌,通过下调A2AR在施万细胞中的表达和活性,减少A2AR下游信号,有助于维持细菌的LD积累和细胞内活力。
UNASSIGNED: Leprosy is a chronic infectious disease caused by Mycobacterium leprae, which can lead to a disabling neurodegenerative condition. M. leprae preferentially infects skin macrophages and Schwann cells-glial cells of the peripheral nervous system. The infection modifies the host cell lipid metabolism, subverting it in favor of the formation of cholesterol-rich lipid droplets (LD) that are essential for bacterial survival. Although researchers have made progress in understanding leprosy pathogenesis, many aspects of the molecular and cellular mechanisms of host-pathogen interaction still require clarification. The purinergic system utilizes extracellular ATP and adenosine as critical signaling molecules and plays several roles in pathophysiological processes. Furthermore, nucleoside surface receptors such as the adenosine receptor A2AR involved in neuroimmune response, lipid metabolism, and neuron-glia interaction are targets for the treatment of different diseases. Despite the importance of this system, nothing has been described about its role in leprosy, particularly adenosinergic signaling (AdoS) during M. leprae-Schwann cell interaction.
UNASSIGNED: M. leprae was purified from the hind footpad of athymic nu/nu mice. ST88-14 human cells were infected with M. leprae in the presence or absence of specific agonists or antagonists of AdoS. Enzymatic activity assays, fluorescence microscopy, Western blotting, and RT-qPCR analysis were performed. M. leprae viability was investigated by RT-qPCR, and cytokines were evaluated by enzyme-linked immunosorbent assay.
UNASSIGNED: We demonstrated that M. leprae-infected Schwann cells upregulated CD73 and ADA and downregulated A2AR expression and the phosphorylation of the transcription factor CREB (p-CREB). On the other hand, activation of A2AR with its selective agonist, CGS21680, resulted in: 1) reduced lipid droplets accumulation and pro-lipogenic gene expression; 2) reduced production of IL-6 and IL-8; 3) reduced intracellular M. leprae viability; 4) increased levels of p-CREB.
UNASSIGNED: These findings suggest the involvement of the AdoS in leprosy neuropathogenesis and support the idea that M. leprae, by downmodulating the expression and activity of A2AR in Schwann cells, decreases A2AR downstream signaling, contributing to the maintenance of LD accumulation and intracellular viability of the bacillus.