Deciphering the proteomic signatures of the optic nerve glial lamina in healthy and glaucomatous conditions

Abstract

Projecting neurons of the central nervous system extend their axons through considerable distances from the cell soma. This extreme architecture requires local regulation driven by proteins whose functions are essential for axonal maintenance and survival. Pathways involved in axon survival represent an important question in neurodegenerative conditions like glaucoma. The loss of visual acuity in glaucoma is caused by the degeneration of retinal ganglion cells (RGCs), that transmit visual signals from the retina to the brain. The principal site of RGC axonal insult occurs where the axons exit the eye, weaving through the honeycomb structure of the glial lamina (GL), at the optic nerve head (ONH). While much is understood about the ONH, the specific molecular pathways involved in local regulation of this crucial area is not fully understood. Furthermore, it is not known how these pathways may be altered in glaucoma, which hinders potential therapeutic intervention. Here, we utilize wild-type and glaucomatous mice to decipher the specific proteomic signature of the GL. By Isolating healthy and glaucomatous GL and RL samples, we performed mass spectrometry proteomics analysis to find proteins specifically enriched in the murine GL. Results from wild-type mice showed enrichment of translation proteins in the GL. At the time this thesis is written, proteomics results on glaucomatous mice are not yet available.