Intercellular Communication Mediating Successful Optic Nerve Regeneration in Zebrafish Identified Through Systems Biology
Matthew B Veldman PhD Medical College of Wisconsin, Cell Biology, Neurobiology, and Anatomy
Unlike glaucoma patients and mammalian experimental models, zebrafish respond to optic nerve injury with robust axon regeneration and virtually no loss of Retinal Ganglion Cells (RGCs). The molecular mechanisms driving RGC survival and axon regeneration in this model have not been thoroughly analyzed. Recent findings suggest that non-RGC cells in the retina and optic nerve support RGC survival and axon regeneration and may represent therapeutically targetable pathways to improve patient outcomes. To systematically analyze intercellular signals mediating optic nerve regeneration in zebrafish, we have performed transcriptomic analysis of laser capture microdissected samples of the RGC layer, inner nuclear layer, and outer nuclear layer as well as the retinal pigmented epithelial layer and optic nerve for comparison of control uninjured and three day post optic nerve crush injury conditions. Three days post injury was chosen because it is an early time point when robust axon regeneration is observed in zebrafish. Integrated analysis of these RNA-seq data sets focused on identifying ligand receptor pairs, cell adhesion molecules, and other extracellular signaling molecules that might support RGC survival and axon regeneration. In addition, we have generated a set of genetic tools with which we will test the identified pathways and cell type-specific role(s) contributing to RGC survival and optic nerve regeneration. This consists of a panel of retina and glial cell type specific promoters from which to conditionally drive gene overexpression or knockout in zebrafish. Future studies will explore the role of identified signaling pathways and molecules in mammalian preclinical models of optic nerve injury and glaucoma.
Funding Sources: Medical College of Wisconsin Research Affairs Committee New Faculty Pilot Grant
