Abstract
Purpose :
Retinal ganglion cell (RGC) degeneration is a primary cause of vision loss in traumatic optic nerve injuries and in optic neuropathies like glaucoma. A therapy that protects RGCs would be transformative but remains elusive. RGCs, like other mammalian neurons in the central nervous system, cannot robustly regenerate axons after injuries. Therefore, our lab seeks to identify therapeutic candidates that promote axon regeneration and cell survival without altering cell-type specific features. We recently identified that the neuropeptides urocortin (UCN) and corticotropin-releasing hormone (CRH) improve RGC survival and stimulate axon regeneration after optic nerve injury. Here, we investigate the signaling pathways that are downstream of CRH/UCN.
Methods :
To test this, we developed gene therapy vectors to overexpress CRH, UCN, and a constitutively-active CRH receptor 1 (CRHR1-CA) in RGCs (AAV2-hSyn). We are using immunohistochemistry to assay known CRH/UCN targets such as cFOS. Additionally, we have optimized techniques for the collection of single-cell RNA sequencing (scRNA-seq), which can measure cell-type specific gene expression changes in an unbiased way.
Results :
Our preliminary studies verify that our gene therapy vectors efficiently infect RGCs and promote axon regeneration. We observed that CRH/UCN overexpression promotes axon regeneration in vivo. Signaling through CRHR1, CRH/UCN might upregulate some downstream effectors such as cFOS. Furthermore, we have collected a control dataset of >40k RGCs for scRNA-seq.
Conclusions :
Our work demonstrates that UCN and CRH could be potential targets for promoting axon regeneration in CNS neurons. We aim to elucidate the underlying mechanisms using in vivo and in vitro systems along with single-cell transcriptomics.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.