Xu Yunhe, Balasubramaniam Balini, Copland David A, Liu Jian, Armitage M John, Dick Andrew D
School of Clinical Sciences, University of Bristol, Bristol, United Kingdom,
Graefes Arch Clin Exp Ophthalmol. 2015 Jul;253(7):1085-96. doi: 10.1007/s00417-015-2961-y. Epub 2015 Feb 14.
Microglia contribute to immune homeostasis of the retina, and thus act as a potential regulator determining successful repair or retinal stem cell transplantation. We investigated the interaction between human microglia and retinal progenitor cells in cell co-culture to further our exploration on developing a new therapeutic strategy for retinal degeneration.
Microglia and retinal progenitor cultures were developed using CD11b(+) and CD133(+), respectively, from adult donor retina. Microglia activation was developed using interferon-gamma and lipopolysaccharide. Retinal progenitor differentiation was analysed in co-culture with or without microglial activation. Retinal progenitor proliferation was analysed in presence of conditioned medium from activated microglia. Phenotype and function of adult human retinal cell cultures were examined using cell morphology, immunohistochemistry and real-time PCR.
By morphology, neuron-like cells generated in co-culture expressed photoreceptor marker recoverin. Neurospheres derived from retinal progenitor cells showed reduced growth in the presence of conditioned medium from activated microglia. Delayed retinal progenitor cell migration and reduced cellular differentiation was observed in co-cultures with activated microglia. In independent experiments, activated microglia showed enhanced mRNA expression of CXCL10, IL-27, IL-6, and TNF-alpha compared to controls.
Adult human retina retains retinal progenitors or potential to reprogram cells to then proliferate and differentiate into neuron-like cells in vitro. Human microglia support retinal progenitor differentiation into neuron-like cells, but such capacity is altered following microglial activation. Modulating microglia activity is a potential approach to promote retinal repair and facilitate success of stem-cell transplantation.
小胶质细胞有助于维持视网膜的免疫稳态，因此作为一种潜在的调节因子，决定着视网膜修复或视网膜干细胞移植是否成功。我们研究了人小胶质细胞与视网膜祖细胞在细胞共培养中的相互作用，以进一步探索开发一种针对视网膜变性的新治疗策略。
分别使用来自成年供体视网膜的CD11b(+)和CD133(+)培养小胶质细胞和视网膜祖细胞。使用干扰素-γ和脂多糖诱导小胶质细胞活化。分析有或没有小胶质细胞活化情况下共培养时视网膜祖细胞的分化情况。在存在活化小胶质细胞条件培养基的情况下分析视网膜祖细胞的增殖情况。使用细胞形态学、免疫组织化学和实时PCR检测成人视网膜细胞培养物的表型和功能。
通过形态学观察，共培养中产生的神经元样细胞表达光感受器标志物恢复蛋白。在存在活化小胶质细胞条件培养基的情况下，源自视网膜祖细胞的神经球生长减缓。在与活化小胶质细胞共培养时观察到视网膜祖细胞迁移延迟和细胞分化减少。在独立实验中，与对照组相比，活化小胶质细胞显示CXCL10、IL-27、IL-6和TNF-α的mRNA表达增强。
成人视网膜保留视网膜祖细胞或具有将细胞重编程的潜力，从而在体外增殖并分化为神经元样细胞。人小胶质细胞支持视网膜祖细胞分化为神经元样细胞，但小胶质细胞活化后这种能力会发生改变。调节小胶质细胞活性是促进视网膜修复和提高干细胞移植成功率的一种潜在方法。
