Grigoryan Eleonora N
Koltsov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia.
Biomedicines. 2020 Jul 12;8(7):208. doi: 10.3390/biomedicines8070208.
Retinal diseases often cause the loss of photoreceptor cells and, consequently, impairment of vision. To date, several cell populations are known as potential endogenous retinal regeneration cell sources (RRCSs): the eye ciliary zone, the retinal pigment epithelium, the iris, and Müller glia. Factors that can activate the regenerative responses of RRCSs are currently under investigation. The present review considers accumulated data on the relationship between the progenitor properties of RRCSs and the features determining their differentiation. Specialized RRCSs (all except the ciliary zone in low vertebrates), despite their differences, appear to be partially "prepared" to exhibit their plasticity and be reprogrammed into retinal neurons due to the specific gene expression and epigenetic landscape. The "developmental" characteristics of RRCS gene expression are predefined by the pathway by which these cell populations form during eye morphogenesis; the epigenetic features responsible for chromatin organization in RRCSs are under intracellular regulation. Such genetic and epigenetic readiness is manifested in vivo in lower vertebrates and in vitro in higher ones under conditions permissive for cell phenotype transformation. Current studies on gene expression in RRCSs and changes in their epigenetic landscape help find experimental approaches to replacing dead cells through recruiting cells from endogenous resources in vertebrates and humans.
视网膜疾病常常导致光感受器细胞丧失，进而造成视力损害。迄今为止，已知有几种细胞群体可作为潜在的内源性视网膜再生细胞来源（RRCSs）：眼睫状体区、视网膜色素上皮、虹膜和 Müller 胶质细胞。目前正在研究能够激活 RRCSs 再生反应的因素。本综述考虑了关于 RRCSs 的祖细胞特性与其分化决定特征之间关系的累积数据。尽管存在差异，但专门的 RRCSs（低等脊椎动物中除睫状体区外的所有细胞群体）似乎部分“准备好”展现其可塑性，并由于特定的基因表达和表观遗传格局而被重编程为视网膜神经元。RRCS 基因表达的“发育”特征由这些细胞群体在眼睛形态发生过程中的形成途径预先确定；负责 RRCSs 染色质组织的表观遗传特征受细胞内调控。这种遗传和表观遗传准备状态在低等脊椎动物体内以及高等脊椎动物体外允许细胞表型转化的条件下得以体现。目前关于 RRCSs 基因表达及其表观遗传格局变化的研究有助于找到通过从脊椎动物和人类的内源性资源中募集细胞来替代死亡细胞的实验方法。
