Origin and development of human retinal astrocyte / 中华实验眼科杂志

ABSTRACT

BackgroundRetinal astrocytes are the main glial cells of retina,their origin and evolution progress are always the hot and difficult points in domestic and foreign researches. ObjectiveThis study was to explore the origin and development of retinal astrocytes in human fetal retina.Methods Thirty-three human embryonic eyes were collected from the abortion with the embryonic ages of 8-12 gestation weeks (20 eyes),15-17 gestation weeks ( 2 eyes),19-23 gestation weeks ( 4 eyes ),25 - 28 gestation weeks ( 4 eyes ),30 - 32 gestation weeks (3 eyes).The section of eyeball wall was prepared to observe the morphology and structure of different embryonic ages of retinas by regular histopathology examination.The origin of human embryonic retinal astrocytes was assessed by evaluating the change of GFAP expression in different embryonic ages of retinas using immunochemistry and immunofluorescence under the light and laser scanning confocal microscope.Theresearch was approved by the the Ethics Committee.Results The optic cup in embryonic 6- 7 weeks was in the retinal layering phase.Some immature short or round spindle-like cells appeared in primitive non-cell layer in the inner layer of the optic cup in embryonic 9 weeks of eyes.There were no positive GFAP-immunoactive cell was detected until embryonic 15 weeks of eyes.Some spindle-like cells migrated from a single layer primitive neuroepithelium next to optic disc expressing GFAP in the eyes with embryonic 19 weeks,and positive immunostaing for GFAP were detected in stellate cells surround blood vessels,and some seem to form the vessel wall in the ganglion cell layer and nerve fiber layer of the fetal central retina from 25 weeks through 26 weeks.Some positive response cells for GFAP presented in inner layer of the retina closed to ora serrata with the connection to nonpigmented epithelium (NPE) of the ciliary body during this period.Human retinal astrocytes showed typical stellate-like in shape,and the cellular processes crossed into inner plexiform layer in embryonic 28-week eyes.Conclusions Human retinal astrocytes mainly seem to have three kinds of origin in human embryonic eyes,and they are vascular precursor cell/pericytes,primitive neuroepithelium and nonpigmented epithelium of the ciliary body.