Lemaire Irma, Falzoni Simonetta, Adinolfi Elena
Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
Front Biosci (Elite Ed). 2012 Jan 1;4(1):41-55. doi: 10.2741/359.
Cell fusion into multinucleated giant cells (MGC) is an essential process that contributes to many important biological mechanisms in mammalians. In the bone and immune system, macrophages are endowed with a remarkable potential for cell fusion events as evidenced by their propensity to fuse with other cells and between themselves during both normal processes and disease. Macrophage fusion is critical for the normal development of multinucleated osteoclasts, the cells responsible for bone resorption. Macrophages from various tissue compartments also undergo fusion into MGC, a hallmark of granulomatous inflammation. To date, the mechanisms underlying macrophage fusion remain poorly understood. Receptor-ligand interactions are thought to mediate this process and several lines of evidence implicate purinergic receptors in both osteoclast and MGC formation. Notably, the P2X7 receptor for extracellular ATP is expressed in osteoclasts and in many types of granulomas associated with infection, foreign body response and sterile inflammation. Through their ability to sense extracellular cues and ATP, a messenger of intercellular communication, purinergic receptors likely contribute to cell-cell interactions that result in macrophage fusion.
细胞融合形成多核巨细胞（MGC）是一个重要过程，它参与哺乳动物许多重要的生物学机制。在骨骼和免疫系统中，巨噬细胞具有显著的细胞融合潜能，在正常过程和疾病期间，它们与其他细胞以及彼此之间融合的倾向就证明了这一点。巨噬细胞融合对于负责骨吸收的多核破骨细胞的正常发育至关重要。来自各种组织区室的巨噬细胞也会融合形成MGC，这是肉芽肿性炎症的一个标志。迄今为止，巨噬细胞融合的潜在机制仍知之甚少。受体 - 配体相互作用被认为介导这一过程，并且有几条证据表明嘌呤能受体与破骨细胞和MGC的形成有关。值得注意的是，细胞外ATP的P2X7受体在破骨细胞以及与感染、异物反应和无菌性炎症相关的多种类型肉芽肿中表达。通过它们感知细胞外信号和细胞间通讯信使ATP的能力，嘌呤能受体可能有助于导致巨噬细胞融合的细胞间相互作用。
