Document Type
Article
Date of Publication
7-19-2023
Publication Title
bioRxiv : the preprint server for biology
Abstract
Degenerative diseases of the outer retina, including age-related macular degeneration (AMD), are characterized by atrophy of photoreceptors and retinal pigment epithelium (RPE). In these blinding diseases, macrophages are known to accumulate ectopically at sites of atrophy, but their ontogeny and functional specialization within this atrophic niche remain poorly understood, especially in the human context. Here, we uncovered a transcriptionally unique profile of microglia, marked by galectin-3 upregulation, at atrophic sites in mouse models of retinal degeneration and in human AMD. Using disease models, we found that conditional deletion of galectin-3 in microglia led to defects in phagocytosis and consequent augmented photoreceptor death, RPE damage and vision loss, suggestive of a protective role. Mechanistically, Trem2 signaling orchestrated the migration of microglial cells to sites of atrophy, and there, induced galectin-3 expression. Moreover, pharmacologic Trem2 agonization led to heightened protection, but only in a galectin-3-dependent manner, further signifying the functional interdependence of these two molecules. Likewise in elderly human subjects, we identified a highly conserved population of microglia at the transcriptomic, protein and spatial levels, and this population was enriched in the macular region of postmortem AMD subjects. Collectively, our findings reveal an atrophy-associated specialization of microglia that restricts the progression of retinal degeneration in mice and further suggest that these protective microglia are conserved in AMD.
DOI
10.1101/2023.07.19.549403
Recommended Citation
Yu, Chen; Lad, Eleonora M.; Mathew, Rose; Littleton, Sejiro; Chen, Yun; Schlepckow, Kai; Degan, Simone; Chew, Lindsey; Amason, Joshua; Kalnitsky, Joan; Rickman, Catherine Bowes; Proia, A D.; Colonna, Marco; Haass, Christian; and Saban, Daniel R., "Microglia at sites of atrophy restrict the progression of retinal degeneration via galectin-3 and trem2 interactions" (2023). Osteopathic Medicine, Jerry M. Wallace School of. 2409.
https://cufind.campbell.edu/medicine_school/2409
