Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.
PLoS One. 2023 Mar 31;18(3):e0283696. doi: 10.1371/journal.pone.0283696. eCollection 2023.
Leishmania is a protozoan that causes leishmaniasis, a neglected tropical disease with clinical manifestations classified as cutaneous, mucocutaneous, and visceral leishmaniasis. In the infection context, the parasite can modulate macrophage gene expression affecting the microbicidal activity and immune response. The metabolism of L-arginine into polyamines putrescine, spermidine, and spermine reduces nitric oxide (NO) production, favoring Leishmania survival. Here, we investigate the effect of supplementation with L-arginine and polyamines in infection of murine BALB/c macrophages by L. amazonensis and in the transcriptional regulation of genes involved in arginine metabolism and proinflammatory response. We showed a reduction in the percentage of infected macrophages upon putrescine supplementation compared to L-arginine, spermidine, and spermine supplementation. Unexpectedly, deprivation of L-arginine increased nitric oxide synthase (Nos2) gene expression without changes in NO production. Putrescine supplementation increased transcript levels of polyamine metabolism-related genes Arg2, ornithine decarboxylase (Odc1), Spermidine synthase (SpdS), and Spermine synthase (SpmS), but reduced Arg1 in L. amazonensis infected macrophages, while spermidine and spermine promoted opposite effects. Putrescine increased Nos2 expression without leading to NO production, while L-arginine plus spermine led to NO production in uninfected macrophages, suggesting that polyamines can induce NO production. Besides, L-arginine supplementation reduced Il-1b during infection, and L-arginine or L-arginine plus putrescine increased Mcp1 at 24h of infection, suggesting that polyamines availability can interfere with cytokine/chemokine production. Our data showed that putrescine shifts L-arginine-metabolism related-genes on BALB/c macrophages and affects infection by L. amazonensis.
利什曼原虫是一种原生动物，可引起利什曼病，这是一种被忽视的热带病，临床表现可分为皮肤利什曼病、黏膜皮肤利什曼病和内脏利什曼病。在感染环境中，寄生虫可以调节巨噬细胞基因表达，影响杀菌活性和免疫反应。L-精氨酸代谢为腐胺、亚精胺和精胺会减少一氧化氮（NO）的产生，有利于利什曼原虫的存活。在这里，我们研究了补充 L-精氨酸和多胺对 L. amazonensis 感染小鼠 BALB/c 巨噬细胞的影响，以及对参与精氨酸代谢和促炎反应的基因的转录调控。我们发现，与 L-精氨酸、亚精胺和精胺相比，腐胺补充后感染巨噬细胞的比例降低。出乎意料的是，剥夺 L-精氨酸会增加一氧化氮合酶（Nos2）基因的表达，而不会改变 NO 的产生。腐胺补充增加了多胺代谢相关基因 Arg2、鸟氨酸脱羧酶（Odc1）、亚精胺合酶（SpdS）和精胺合酶（SpmS）的转录水平，但减少了 L. amazonensis 感染巨噬细胞中的 Arg1，而亚精胺和精胺则产生相反的效果。腐胺增加了 Nos2 的表达，但没有导致 NO 的产生，而 L-精氨酸加精胺则导致未感染的巨噬细胞产生 NO，这表明多胺可以诱导 NO 的产生。此外，L-精氨酸补充减少了感染期间的 Il-1b，而 L-精氨酸或 L-精氨酸加腐胺在感染 24 小时增加了 Mcp1，这表明多胺的可用性会干扰细胞因子/趋化因子的产生。我们的数据表明，腐胺改变了 BALB/c 巨噬细胞中的 L-精氨酸代谢相关基因，并影响了 L. amazonensis 的感染。
