Nitric oxide produced by periostial hemocytes modulates the bacterial infection-induced reduction of the mosquito heart rate
Nitric oxide produced by periostial hemocytes modulates the bacterial infection-induced reduction of the mosquito heart rate
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DOI：
10.1242/jeb.225821
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发表时间：
2020-08-01
影响因子：
2.8
通讯作者：
Hillyer, Julian F.
中科院分区：
文献类型：
--
作者：
Estevez-Lao, Tania Y.;Sigle, Leah T.;Hillyer, Julian F.
蚊子的循环系统和免疫系统在功能上是一体化的。感染诱导血细胞迁移到背侧血管，特别是心脏口周围的区域。这些孔周血细胞吞噬血腔中血淋巴流量最高的区域的病原体。在这里，我们调查了细菌感染是否会影响非洲疟疾蚊子冈比亚按蚊的心律。我们发现，感染大肠杆菌、金黄色葡萄球菌和表皮葡萄球菌，而不是藤黄微球菌，会降低蚊子的心率，改变心脏收缩的比例方向。感染不会改变编码甲壳动物心脏活性肽（CCAP）、FMRFamide、corazonin、神经肽F或短神经肽F的基因的表达，表明它们不会驱动心脏表型。感染上调两个超氧化物歧化酶（SOD）基因，过氧化氢酶和谷胱甘肽过氧化物酶的转录，但显着诱导上调一氧化氮合酶（NOS）在心脏和血细胞。在心脏内，一氧化氮合酶由孔周血细胞产生，并且使用L-NAME化学抑制一氧化氮的产生逆转感染诱导的心脏表型。最后，感染诱导心脏和其他组织中两种溶菌酶基因的上调，用溶菌酶治疗蚊子会降低心率，这让人想起感染表型。这些数据展示了昆虫免疫和循环系统之间整合的一个令人兴奋的新方面，即血细胞产生的具有免疫活性的因子，即一氧化氮，调节心脏生理学。
The circulatory and immune systems of mosquitoes are functionally integrated. An infection induces the migration of hemocytes to the dorsal vessel, and specifically, to the regions surrounding the ostia of the heart. These periostial hemocytes phagocytose pathogens in the areas of the hemocoel that experience the highest hemolymph flow. Here, we investigated whether a bacterial infection affects cardiac rhythmicity in the African malaria mosquito, Anopheles gambiae. We discovered that infection with Escherichia coli, Staphylococcus aureus and Staphylococcus epidermidis, but not Micrococcus luteus, reduces the mosquito heart rate and alters the proportional directionality of heart contractions. Infection does not alter the expression of genes encoding crustacean cardioactive peptide (CCAP), FMRFamide, corazonin, neuropeptide F or short neuropeptide F, indicating that they do not drive the cardiac phenotype. Infection upregulates the transcription of two superoxide dismutase (SOD) genes, catalase and a glutathione peroxidase, but dramatically induces upregulation of nitric oxide synthase (NOS) in both the heart and hemocytes. Within the heart, nitric oxide synthase is produced by periostial hemocytes, and chemically inhibiting the production of nitric oxide using L-NAME reverses the infection-induced cardiac phenotype. Finally, infection induces the upregulation of two lysozyme genes in the heart and other tissues, and treating mosquitoes with lysozyme reduces the heart rate in amanner reminiscent of the infection phenotype. These data demonstrate an exciting new facet of the integration between the immune and circulatory systems of insects, whereby a hemocyte-produced factor with immune activity, namely nitric oxide, modulates heart physiology.