Kaplan M W
Neurological Sciences Institute, Oregon Health Sciences University, Portland 97209-1595, USA.
Curr Eye Res. 1998 Aug;17(8):793-7.
The sclerad surface of the retina is exposed to serum proteins in several retinal pathologies that result in degeneration of photoreceptor outer segments. Abnormal disk membrane morphogenesis is observed in rod photoreceptors of detached Xenopus retinas when they are cultured in serum-containing medium. Retinas that remain attached to the pigment epithelium layer produce normal disks. Experiments were conducted to determine whether abnormal disk morphogenesis in detached, cultured retinas is due to the presence of serum in the microenvironment of the rod outer segments.
Detached retinas and retinas attached to the retinal pigment epithelium in eyecups were cultured in either serum-containing or serum-free medium, and the morphology of the disk lamellae formed in vitro retinas was evaluated. Using protein extraction and immunochemical methods, the presence of albumin in the microenvironment of the outer segments was confirmed for retinas incubated in serum-containing medium.
There were no obvious differences in the abnormal disk-like lamellae formed in detached retinas when the retinas were incubated either in serum-containing or in serum-free culture medium. Proteins extracted from detached retinas cultured in serum-containing medium showed a prominent band at 63 kDa that co-localized primarily with outer segment-enriched fractions. Immunolabeling showed that the band was serum albumin.
Rod cells in detached retinas formed abnormal disk-like lamellar membranes in either serum-containing or serum-free medium. This suggests that exposing outer segments to serum albumin or other serum components is not responsible for the abnormal in vitro disk membrane morphogenesis seen in detached retinas.
在几种导致光感受器外段退化的视网膜病变中，视网膜的巩膜表面会暴露于血清蛋白。当非洲爪蟾分离的视网膜在含血清培养基中培养时，可观察到视杆光感受器中出现异常的盘膜形态发生。仍与色素上皮层相连的视网膜会产生正常的盘。进行实验以确定分离的培养视网膜中异常的盘膜形态发生是否是由于视杆外段微环境中存在血清。
将分离的视网膜和眼杯中与视网膜色素上皮相连的视网膜分别在含血清或无血清培养基中培养，并评估体外培养视网膜中形成的盘状片层的形态。使用蛋白质提取和免疫化学方法，证实了在含血清培养基中孵育的视网膜外段微环境中存在白蛋白。
当分离的视网膜在含血清或无血清培养基中孵育时，形成的异常盘状片层没有明显差异。从在含血清培养基中培养的分离视网膜中提取的蛋白质在63 kDa处显示出一条突出的条带，该条带主要与富含外段的组分共定位。免疫标记显示该条带为血清白蛋白。
分离的视网膜中的视杆细胞在含血清或无血清培养基中均形成异常的盘状层膜。这表明将外段暴露于血清白蛋白或其他血清成分并非分离视网膜中所见的体外盘膜异常形态发生的原因。
