Guo Yan, Saloupis Peter, Shaw Steven J, Rickman Dennis W
Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Invest Ophthalmol Vis Sci. 2003 Jul;44(7):3194-201. doi: 10.1167/iovs.02-0875.
To optimize delivery parameters for achieving engraftment, migration, and differentiation of adult neural progenitor cells transplanted to the retinas of rats after transient retinal ischemia.
Retinal ischemia was induced by transiently raising the intraocular pressure. Some animals then received transplantation of green fluorescent protein (GFP)-expressing cells derived from the adult rat hippocampus and were allowed to recover for 6 hours to 9 weeks. Retinal cryosections were prepared for TUNEL analysis to determine the time course of ischemia-induced cell death, and some sections were prepared for immunohistochemistry for retinal neuronal antigens.
TUNEL analysis revealed that ischemia-induced cell death peaked at 24 hours. By 96 hours, the inner nuclear (INL) and ganglion cell (GCL) layers were largely obliterated in the central retina, sparing peripheral regions. By 2 weeks after transplantation, numerous GFP-expressing cells had engrafted into the host retina, migrated to the inner retina, and extended processes. At 4 weeks, many GFP-labeled cells were present throughout the INL and displayed horizontal-, bipolar-, and amacrine cell-like morphologies. GFP-expressing cells were also present in the GCL with fibers extending into the nerve fiber layer. At 5 weeks, many GFP-expressing cells were present at the optic nerve head, and some GFP-labeled fibers were present in the optic nerve, occasionally passing through the full extent of the lamina cribrosa. Only rarely were GFP-expressing cells found that coexpressed retinal phenotypic markers at any time point examined.
Adult hippocampus-derived neural progenitor cells transplanted to the subretinal space readily engraft into a host retina that has undergone ischemic injury. Many cells migrate to specific retinal cellular layers and undergo limited morphologic differentiation reminiscent of retinal neurons, including extension of processes into the optic nerve. Concurrent control studies demonstrate that optimal engraftment is achieved by subretinal delivery within a specific temporal window. These results imply that certain inductive cues may be regulated after injury, and they demonstrate the potential for adult neural progenitor cell transplantation for the treatment of retinal neurodegenerative diseases.
优化递送参数，以实现成年神经祖细胞移植到短暂性视网膜缺血后的大鼠视网膜后的植入、迁移和分化。
通过短暂升高眼压诱导视网膜缺血。然后，一些动物接受了源自成年大鼠海马体的绿色荧光蛋白（GFP）表达细胞的移植，并使其恢复6小时至9周。制备视网膜冰冻切片用于TUNEL分析，以确定缺血诱导的细胞死亡的时间进程，并且一些切片用于视网膜神经元抗原的免疫组织化学分析。
TUNEL分析显示，缺血诱导的细胞死亡在24小时达到峰值。到96小时时，视网膜中央的内核层（INL）和神经节细胞层（GCL）在很大程度上消失，周边区域得以保留。移植后2周，大量表达GFP的细胞植入宿主视网膜，迁移到视网膜内层，并伸出突起。在4周时，整个INL中存在许多GFP标记的细胞，并呈现出水平细胞、双极细胞和无长突细胞样形态。表达GFP的细胞也存在于GCL中，其纤维延伸到神经纤维层。在5周时，许多表达GFP的细胞出现在视神经乳头处，并且一些GFP标记的纤维存在于视神经中，偶尔穿过筛板的整个范围。在所检查的任何时间点，仅很少发现共表达视网膜表型标记的表达GFP的细胞。
移植到视网膜下间隙的成年海马体来源的神经祖细胞很容易植入经历过缺血性损伤的宿主视网膜。许多细胞迁移到特定的视网膜细胞层，并经历有限的形态分化，类似于视网膜神经元，包括突起延伸到视神经。同期对照研究表明，在特定的时间窗内通过视网膜下递送可实现最佳植入。这些结果表明，损伤后某些诱导信号可能受到调节，并且它们证明了成年神经祖细胞移植治疗视网膜神经退行性疾病的潜力。
