Kelly Lisa E, El-Hodiri Heithem M, Crider Andrew, Fischer Andy J
Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, USA.
Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, USA.
Mol Cell Neurosci. 2024 Jun;129:103932. doi: 10.1016/j.mcn.2024.103932. Epub 2024 Apr 26.
Different kinase-dependent cell signaling pathways are known to play important roles in glia-mediated neuroprotection and reprogramming of Müller glia (MG) into Müller glia-derived progenitor cells (MGPCs) in the retina. However, very little is known about the phosphatases that regulate kinase-dependent signaling in MG. Using single-cell RNA-sequencing (scRNA-seq) databases, we investigated patterns of expression of Dual Specificity Phosphatases (DUSP1/6) and other protein phosphatases in normal and damaged chick retinas. We found that DUSP1, DUSP6, PPP3CB, PPP3R1 and PPPM1A/B/D/E/G are widely expressed by many types of retinal neurons and are dynamically expressed by MG and MGPCs in retinas during the process of reprogramming. We find that inhibition of DUSP1/6 and PP2C phosphatases enhances the formation of proliferating MGPCs in damaged retinas and in retinas treated with insulin and FGF2 in the absence of damage. By contrast, inhibition of PP2B phosphatases suppressed the formation of proliferating MGPCs, but increased numbers of proliferating MGPCs in undamaged retinas treated with insulin and FGF2. In damaged retinas, inhibition of DUSP1/6 increased levels of pERK1/2 and cFos in MG whereas inhibition of PP2B's decreased levels of pStat3 and pS6 in MG. Analyses of scRNA-seq libraries identified numerous differentially activated gene modules in MG in damaged retinas versus MG in retinas treated with insulin+FGF2 suggesting significant differences in kinase-dependent signaling pathways that converge on the formation of MGPCs. Inhibition of phosphatases had no significant effects upon numbers of dying cells in damaged retinas. We conclude that the activity of different protein phosphatases acting through retinal neurons and MG "fine-tune" the cell signaling responses of MG in damaged retinas and during the reprogramming of MG into MGPCs.
已知不同的激酶依赖性细胞信号通路在神经胶质细胞介导的神经保护以及视网膜中穆勒胶质细胞（MG）重编程为穆勒胶质细胞衍生祖细胞（MGPCs）的过程中发挥重要作用。然而，对于调节MG中激酶依赖性信号传导的磷酸酶却知之甚少。利用单细胞RNA测序（scRNA-seq）数据库，我们研究了双特异性磷酸酶（DUSP1/6）和其他蛋白磷酸酶在正常和受损鸡视网膜中的表达模式。我们发现，DUSP1、DUSP6、PPP3CB、PPP3R1和PPPM1A/B/D/E/G在多种视网膜神经元中广泛表达，并且在重编程过程中在视网膜的MG和MGPCs中动态表达。我们发现，抑制DUSP1/6和PP2C磷酸酶可增强受损视网膜以及在无损伤情况下用胰岛素和FGF2处理的视网膜中增殖性MGPCs的形成。相比之下，抑制PP2B磷酸酶会抑制增殖性MGPCs的形成，但在用胰岛素和FGF2处理的未受损视网膜中增殖性MGPCs的数量会增加。在受损视网膜中，抑制DUSP1/6会增加MG中pERK1/2和cFos的水平，而抑制PP2B则会降低MG中pStat3和pS6的水平。对scRNA-seq文库的分析确定了受损视网膜中的MG与用胰岛素+FGF2处理的视网膜中的MG之间存在许多差异激活的基因模块，这表明在汇聚于MGPCs形成的激酶依赖性信号通路中存在显著差异。抑制磷酸酶对受损视网膜中死亡细胞的数量没有显著影响。我们得出结论，通过视网膜神经元和MG起作用的不同蛋白磷酸酶的活性在受损视网膜以及MG重编程为MGPCs的过程中“微调”了MG的细胞信号反应。
