2014年12月10日 訊 /生物谷BIOON/ --巨噬細胞是我們機體中強大的「吃豆小精靈」,其可以吞咽細胞殘渣及病原體來保護機體健康,近日,一篇刊登在國際雜誌The Journal of Cell Biology上的研究論文中,來自威斯康辛-邁迪遜大學大學的研究人員揭示了巨噬細胞如何通過誘導中性白細胞,使其離開機體損傷的組織進而幫助治療炎症。
中性粒細胞是機體中的「第一急救者」,其可以被名為活性氧激活的蛋白激酶所吸引到患處,當中性粒細胞完成工作後,炎症就會通過細胞自殺或凋亡的方式被部分治療,隨後殘留的中性粒細胞就會被巨噬細胞所吞噬;但中性粒細胞可以通過一種逆向遷移的方式離開機體損傷的組織,目前是否巨噬細胞可以促進炎症的恢復尚不明確。
這項研究中,研究人員利用透明的斑馬魚幼體進行研究,結果發現,在被巨噬細胞吞噬前中性粒細胞會被「招募」至傷口處,但是一旦其到達傷口處,巨噬細胞就會同中性粒細胞進行接觸,並且使其遠離機體損傷組織;在缺失巨噬細胞的斑馬魚機體中中性粒細胞可以在斑馬魚患處停留很長時間。就像中性粒細胞一樣,巨噬細胞可以被活性氧和蛋白激酶信號吸引至患處,而且缺失活性氧產生酶類Nox2的巨噬細胞並不能遷移至傷口處,反而會誘導中性粒細胞離開傷口。
更有意思的是,研究人員發現,缺失人類等量Nox2的病人往往會遭受感染的復發及炎性的擴展,這種障礙名為慢性肉芽腫病;本文研究揭示了一種引發病人患慢性肉芽腫病的原因或許是因為機體巨噬細胞並不能遷移到炎性位點來誘導中性粒細胞的反向遷移活動及炎性的恢復。(生物谷Bioon.com)
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Redox and Src family kinase signaling control leukocyte wound attraction and neutrophil reverse migration
Sebastien Tauzin,1 Taylor W. Starnes,2 Francisco Barros Becker,1,3 Pui-ying Lam,1,3 and Anna Huttenlocher1
Tissue damage induces early recruitment of neutrophils through redox-regulated Src family kinase (SFK) signaling in neutrophils. Redox-SFK signaling in epithelium is also necessary for wound resolution and tissue regeneration. How neutrophil-mediated inflammation resolves remains unclear. In this paper, we studied the interactions between macrophages and neutrophils in response to tissue damage in zebrafish and found that macrophages contact neutrophils and induce resolution via neutrophil reverse migration. We found that redox-SFK signaling through p22phox and Yes-related kinase is necessary for macrophage wound attraction and the subsequent reverse migration of neutrophils. Importantly, macrophage-specific reconstitution of p22phox revealed that macrophage redox signaling is necessary for neutrophil reverse migration. Thus, redox-SFK signaling in adjacent tissues is essential for coordinated leukocyte wound attraction and repulsion through pathways that involve contact-mediated guidance.