GSE201254
Overlapping transcriptional programs promote survival and axonal regeneration of injured retinal ganglion cells [1]
Neurons of the central nervous system (CNS) display only a limited ability to survive and regenerate their axons after an injury. In mice, 85% of retinal ganglion cells (RGCs) die within 2 weeks of axotomy by optic nerve crush (ONC) and only few survivors regenerate axons. In the past years, a multitude of interventions have been identified to improve RGC survival and regeneration after an injury, however, each only protects a subset of neurons and stimulates axon regrowth in an even smaller set.. Here, we sought out to elucidate the molecular mechanisms underlying this selective responsiveness and investigated genes regulated by three well established survival and regeneration-promoting interventions – activation of the MTOR pathway via deletion of its inhibitor Pten, activation of the Jak/Stat-pathway by deletion of its endogenous inhibitor Socs3, and overexpression of the neurotrophic cytokine CNTF. Analysis of the transcriptomes from >125,000 single RGCs at various time points after ONC showed that while broad survival of all RGC types could be induced with each intervention, type-independent axon regeneration was only overcome with the manipulation of multiple pathways. Those RGCs were able to mitigate the injury response and simultaneously upregulated survival and regeneration associated programs (prior and after injury). Four independent ways of analysis identified these programs to be differentially regulated among RGCs, with distinct signatures for degenerating, surviving and regenerating cells. Finally, testing some genes associated with the regeneration-program in vivo identified potential future therapeutic targets to promote neuroprotection and axonal regeneration. Overall design: In these experiments, we FACS sorted for retinal ganglion cells using a combination of a transgenic reporter (Thy1-YFP17) crossed with Pten fl/fl or Pten/Socs3 fl/fl mice and a surface protein (CD90) from dissociated retinas of adult (6-8 wk old) mice, including uninjured controls, and at 3 time points following optic nerve crush (2d, 7d, 21d).