부산대학교 도서관

Astrocyte motility plays an important role in the response of the brain to injury and during regeneration. We used two in vitroassays, a wound‐healing model and a chemotaxis assay, to study mechanisms that control astrocyte motility. Ryanodine receptors (RyR), intracellular calcium‐release channels, modulate intracellular Ca2+levels, and also motility: 1) blocking RyR with antagonizing concentration of ryanodine (200 μM) strongly attenuated motility and 2) motility of astrocytes cultured from homozygous RyR type 3 knockout mice was impaired strongly compared with wild‐type. In contrast, MIP‐1α‐induced chemotaxis was neither impaired in the presence of ryanodine nor in the cells from the knockout animals. Reverse transcription‐polymerase chain reaction (RT‐PCR) analysis combined with Western blotting and immunocytochemistry confirmed the expression of RyR type 3, but not type 1 or 2 in cultured and acutely isolated astrocytes. RyR in astrocytes are linked to Ca2+signaling because the RyR agonist 4‐chloro‐m‐cresol induced a release of Ca2+from intracellular stores. These results indicate that astrocytes express only RyR type 3 and that this receptor is important for controlling astrocyte motility.