Liu Bin, Neufeld Arthur H
Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
Dev Biol. 2004 Sep 15;273(2):297-307. doi: 10.1016/j.ydbio.2004.06.006.
In postnatal developing optic nerves, astrocytes organize their processes in a cribriform network to group axons into bundles. In neonatal rat optic nerves in vivo, the active form of EGFR tyrosine kinase is abundantly present when the organization of astrocytes and axons is most actively occurring. Blocking activity of EGFR tyrosine kinase during the development of rat optic nerves in vivo inhibits astrocytes from extending fine processes to surround axons. In vitro, postnatal optic nerve astrocytes, stimulated by EGF, organize into cribriform structures which look remarkably like the in vivo structure of astrocytes in the optic nerve. In addition, when astrocytes are co-cultured with neonatal rat retinal explants in the presence of EGF, astrocytes that are adjacent to the retinal explants, re-organize to an astrocyte-free zone into which neurites grow out from the retinal tissue. We hypothesize that in the developing optic nerve, EGFR activity directs the formation of a histo-architectural structure of astrocytes which surrounds axons and provides a permissive environment for axon development.
在出生后发育的视神经中，星形胶质细胞将其突起组织成筛状网络，将轴突聚集成束。在新生大鼠体内视神经中，当星形胶质细胞和轴突的组织最活跃地发生时，EGFR酪氨酸激酶的活性形式大量存在。在大鼠体内视神经发育过程中阻断EGFR酪氨酸激酶的活性会抑制星形胶质细胞伸出精细突起以包围轴突。在体外，出生后视神经星形胶质细胞受表皮生长因子（EGF）刺激后会组织成筛状结构，这与视神经中星形胶质细胞的体内结构非常相似。此外，当星形胶质细胞在EGF存在的情况下与新生大鼠视网膜外植体共培养时，与视网膜外植体相邻的星形胶质细胞会重新组织成一个无星形胶质细胞区，神经突从视网膜组织生长到这个区域。我们假设在发育中的视神经中，EGFR活性指导星形胶质细胞形成围绕轴突的组织架构结构，并为轴突发育提供一个许可环境。
