Single-cell transcriptome atlas of spontaneous dry age-related macular degeneration in macaques.

Age-related macular degeneration is the leading cause of irreversible visual impairment in the elderly. It manifests in two forms, wet and dry. However, the mechanisms underlying spontaneous dry age-related macular degeneration (SD-AMD) remain unclear. Herein, we constructed a single-cell retinal transcription atlas in aged non-human primates with SD-AMD. Retinal tissues affected by SD-AMD exhibited a more degenerative and dysfunctional transcriptomic landscape, with global activation of the oxidative stress response and apoptotic signaling pathway. We found two distinct Müller glia subtypes in normal aged and SD-AMD macaques, one exhibiting a photoreceptor-like transcriptome and the other exhibiting a typical Müller glia transcriptome. As SD-AMD progressed, the proportion of photoreceptor-like Müller glial cells decreased, and photoreceptor-function-associated genes were downregulated, indicating weaker Müller glia potential to transit into photoreceptor-like functional states. Microglial cells showed activated features, and the complement system was activated during disease pathogenesis. We also found that the disruption of iron homeostasis and ferroptosis could promote SD-AMD pathogenesis in neural cells. Further experimentation revealed that a ferroptosis inhibitor exerted a profound rescuing effect in SD-AMD mouse models. Based on these results, our study introduces a path toward understanding the pathogenesis of SD-AMD in a non-human primate model at single-cell resolution.