RT Journal Article SR Electronic T1 Atypical Cadherin FAT3 Is a Novel Mediator for Morphological Changes of Microglia JF eneuro JO eNeuro FD Society for Neuroscience SP ENEURO.0056-20.2020 DO 10.1523/ENEURO.0056-20.2020 VO 7 IS 6 A1 Tomomi Okajima A1 Yichen Gu A1 Rin-ichiro Teruya A1 Sarasa Yano A1 Takumi Taketomi A1 Ban Sato A1 Tomoki Chiba A1 Fuminori Tsuruta YR 2020 UL http://www.eneuro.org/content/7/6/ENEURO.0056-20.2020.abstract AB Microglia are resident macrophages that are critical for brain development and homeostasis. Microglial morphology is dynamically changed during postnatal stages, leading to regulating synaptogenesis and synapse pruning. Moreover, it has been well known that the shape of microglia is also altered in response to the detritus of the apoptotic cells and pathogens such as bacteria and viruses. Although the morphologic changes are crucial for acquiring microglial functions, the exact mechanism which controls their morphology is not fully understood. Here, we report that the FAT atypical cadherin family protein, FAT3, regulates the morphology of microglial cell line, BV2. We found that the shape of BV2 becomes elongated in a high-nutrient medium. Using microarray analysis, we identified that FAT3 expression is induced by culturing with a high-nutrient medium. In addition, we found that purinergic analog, hypoxanthine, promotes FAT3 expression in BV2 and mouse primary microglia. FAT3 expression induced by hypoxanthine extends the time of sustaining the elongated forms in BV2. These data suggest that the hypoxanthine-FAT3 axis is a novel pathway associated with microglial morphology. Our data provide a possibility that FAT3 may control microglial transitions involved in their morphologic changes during the postnatal stages in vivo.