Xu Jie, Li Yi, Li Xiangyu, Tan Xuan, Liu Lihua, Cao Lining, Xu Hui
Key Lab of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu Province, China.
Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China.
Invest Ophthalmol Vis Sci. 2025 Apr 1;66(4):67. doi: 10.1167/iovs.66.4.67.
Inflammation activates the Jak1-Stat3 signaling pathway in zebrafish Müller glia (MG), leading to their status transition and proliferation following retinal injury. However, the source of Stat3-activating molecules remains unclear. This study aims to explore the expression and function of a Stat3-activating cytokine IL-6 in zebrafish retina regeneration.
Mechanical retinal injury was induced in adult zebrafish by a needle-poke lesion. Single-cell RNA sequencing (scRNAseq) and PCR were used to determine gene expression. Microglia ablation was performed by using the mpeg1:nsfb-mcherry transgenic zebrafish. Morpholino oligonucleotides, a recombinant zebrafish IL-6 protein and drugs, were used to manipulate IL-6 or Stat3 signaling in the retina. The 5-Ethynyl-2'-deoxyuridine (EdU) labeling was used to evaluate MG proliferation and the formation of MG-derived progenitor cells (MGPCs). Neuronal regeneration in the retina was analyzed by lineage tracing and immunostaining.
The scRNAseq reveals that IL-6 is mainly expressed by a subset of pro-inflammatory microglia in the injured retina. Loss- and gain-of-function experiments demonstrate that IL-6 signaling promotes MG proliferation and the formation of MGPCs following retinal injury. Additionally, IL-6 facilitates MG status transition by modulating Jak1-Stat3 signaling and the expression of regeneration-associated genes. Interestingly, IL-6 may also regulate MGPC formation via phase-dependent pro-inflammatory and anti-inflammatory mechanisms. Finally, IL-6 promotes the early differentiation of MGPCs and contributes to the regeneration of retinal neurons in the injured retina.
Our study unveils the critical role of microglia-derived IL-6 in zebrafish retina regeneration, with potential implications for mammalian MG reprogramming.
炎症激活斑马鱼穆勒胶质细胞（MG）中的Jak1-Stat3信号通路，导致视网膜损伤后其状态转变和增殖。然而，激活Stat3的分子来源尚不清楚。本研究旨在探索一种激活Stat3的细胞因子IL-6在斑马鱼视网膜再生中的表达及功能。
通过针刺损伤诱导成年斑马鱼发生机械性视网膜损伤。采用单细胞RNA测序（scRNAseq）和聚合酶链反应（PCR）来确定基因表达。利用mpeg1:nsfb-mcherry转基因斑马鱼进行小胶质细胞消融。使用吗啉代寡核苷酸、重组斑马鱼IL-6蛋白和药物来调控视网膜中的IL-6或Stat3信号。采用5-乙炔基-2'-脱氧尿苷（EdU）标记来评估MG增殖以及MG衍生祖细胞（MGPCs）的形成。通过谱系追踪和免疫染色分析视网膜中的神经元再生。
scRNAseq显示，IL-6主要由受损视网膜中的一群促炎性小胶质细胞表达。功能缺失和功能获得实验表明，IL-6信号通路促进视网膜损伤后MG增殖和MGPCs的形成。此外，IL-6通过调节Jak1-Stat3信号通路和再生相关基因的表达来促进MG状态转变。有趣的是，IL-6还可能通过阶段依赖性促炎和抗炎机制调节MGPCs的形成。最后，IL-6促进MGPCs的早期分化，并有助于受损视网膜中视网膜神经元的再生。
我们的研究揭示了小胶质细胞衍生的IL-6在斑马鱼视网膜再生中的关键作用，对哺乳动物MG重编程具有潜在意义。
