Chen Jing, Lu Tu, Chen Chen, Zheng Wenbin, Lu Lin, Li Naiyang
Department of Ophthalmology, Zhongshan City People's Hospital, Zhongshan, Guangdong, China.
Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China.
Eur J Med Res. 2024 Dec 23;29(1):615. doi: 10.1186/s40001-024-02163-1.
Age-related macular degeneration (AMD), is a neurodegenerative ocular disease. This study investigated the role of ferroptosis-related genes and their interaction with immune cell infiltration in AMD.
We screened differential expression genes (DEGs) of AMD from data sets in Gene Expression Omnibus. We identified ferroptosis-related differentially expressed genes (ferroDEGs) by intersecting DEGs with ferroptosis-related genes. Protein-protein interactions network and Cytoscape were used for screening hub genes. Next, we analyzed immune cell infiltration using CIBERSORT and examined the crosstalk between hub ferroDEGs and immune cell infiltration. Hub genes expression in each cell cluster and the proportions of different cell clusters between AMD and normal samples were examined using single-cell data. The hub ferroDEG expressions were verified in cell and mouse models using RT-qPCR, western blot, and immunofluorescence assay. The roles of ANXA1 in ferroptosis and its crosstalk with microglia were investigated.
We identified hub ferroDEGs that include six genes (ANXA1, DKK1, CD44, VIM, TGFB2, DUSP1). Functional analysis of those hub ferroDEGs was found to be correlated with leukocyte migration and chemotaxis, macrophage migration, and gliogenesis. The high-risk ferroptosis group exhibited elevated levels of CD8 T cells, activated NK cells, and M2 macrophages. Single-cell sequencing data revealed a high degree of cell heterogeneity in macular degeneration and the monocytes proportion in the macular area was higher in AMD samples. Moreover, we observed elevated mRNA and protein levels of CD44, ANXA1 (P < 0.01), while ANXA1 knockdown reduced GPX4 expression in the cell model. Finally, we validated increased ANXA1 expression and observed its colocalization with microglia in mouse models using immunofluorescence assays.
This study offers insights into the AMD pathogenesis and identifies ANXA1 as a potential target related to protecting from ferroptosis and immune response for future research.
年龄相关性黄斑变性（AMD）是一种神经退行性眼病。本研究调查了铁死亡相关基因在AMD中的作用及其与免疫细胞浸润的相互作用。
我们从基因表达综合数据库的数据集中筛选AMD的差异表达基因（DEGs）。通过将DEGs与铁死亡相关基因相交，鉴定出铁死亡相关差异表达基因（ferroDEGs）。使用蛋白质-蛋白质相互作用网络和Cytoscape筛选枢纽基因。接下来，我们使用CIBERSORT分析免疫细胞浸润，并检查枢纽ferroDEGs与免疫细胞浸润之间的相互作用。使用单细胞数据检查每个细胞簇中枢纽基因的表达以及AMD与正常样本之间不同细胞簇的比例。使用RT-qPCR、蛋白质印迹和免疫荧光测定法在细胞和小鼠模型中验证枢纽ferroDEG的表达。研究了膜联蛋白A1（ANXA1）在铁死亡中的作用及其与小胶质细胞的相互作用。
我们鉴定出包括六个基因（ANXA1、DKK1、CD44、波形蛋白、转化生长因子β2、双特异性磷酸酶1）的枢纽ferroDEGs。发现这些枢纽ferroDEGs的功能分析与白细胞迁移和趋化性、巨噬细胞迁移和成胶质细胞生成相关。高风险铁死亡组的CD8 T细胞、活化的自然杀伤细胞和M2巨噬细胞水平升高。单细胞测序数据显示黄斑变性中细胞异质性程度高，且AMD样本中黄斑区的单核细胞比例更高。此外，我们观察到CD44、ANXA1的mRNA和蛋白质水平升高（P < 0.01），而在细胞模型中敲低ANXA1可降低谷胱甘肽过氧化物酶4（GPX4）的表达。最后，我们使用免疫荧光测定法在小鼠模型中验证了ANXA1表达增加，并观察到其与小胶质细胞共定位。
本研究为AMD的发病机制提供了见解，并确定ANXA1作为未来研究中与保护免受铁死亡和免疫反应相关的潜在靶点。
