title: Essential role of MFG-E8 for phagocytic properties of microglial cells.
abstract: Milk fat globule factor-E8 (MFG-E8) has been regarded as a key factor involved in the phagocytosis of apoptotic cells. We induced a lentivirus into the microglial cells for the augmentation or abrogation of MFG-E8 expression in mouse microglial cells, and investigated phagocytosis of phosphatidylserine tagged human red blood cells (hRBCs) in co-cultures. Increased MFG-E8 levels were associated with a significant increase in phagocytic activity compared to the controls. Conversely, phagocytosis dramitically decreased due to the abrogation of MFG-E8. In addition, the expression of the inflammatory cytokines, TNF-α and IL-1β, also increased or decreased in the microglial cells with the augmentation or abrogation of MFG-E8, respectively. Our findings indicate that the enhanced expression of MFG-E8 could increase phagocytosis of apoptotic cells; conversely, the rate of phagocytosis and the expression of inflammatory cytokines decreased when MFG-E8 expression was knocked down. Our results confirm that MFG-E8 plays an important role in phagocytosis, and possibly serves as an essential signal molecule for microglial cells.
authors: Southwest Hospital, Southwest Eye Hospital, Third Military Medical University, Chongqing, China. liu_yong2012@yahoo.com
authors: Yong
authors: Y
authors: Liu
authors: Xuesen
authors: X
authors: Yang
authors: Chenying
authors: C
authors: Guo
authors: Pan
authors: P
authors: Nie
authors: Yan
authors: Y
authors: Liu
authors: Jie
authors: J
authors: Ma
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism*; D017209:Apoptosis; D015153:Blotting, Western; D002478:Cells, Cultured; D018920:Coculture Techniques; D004912:Erythrocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D008894:Milk Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010587:Phagocytosis / Q000502:physiology*; D010718:Phosphatidylserines / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000954:Antigens, Surface; C490919:Mfge8 protein, mouse; D008894:Milk Proteins; D010718:Phosphatidylserines; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014409:Tumor Necrosis Factor-alpha