Affiliations: Department of Experimental Ophthalmology, University
Eye Hospital Münster, Münster, Germany | Interdisciplinary Center of Clinical Research (IZKF)
Münster, Unit of Integrated functional Genomics (IFG), Münster,
Germany | Department of Neurobiology, University of Oldenburg,
Oldenburg, Germany | Institute of Reproductive Medicine, University of
Münster, Münster, Germany
Note: [] Corresponding author: S. Thanos, Department of Experimental
Ophthalmology, School of Medicine; University of Münster, Domagkstraşe
15, D-48149 Münster, Germany. Tel.: +49 251 8356915; Fax: +49 251 8356916;
E-mail: solon@uni-muenster.de
Abstract: Injury to the mature primate and subprimate optic nerve results in
irreversible impairment and loss of vision, because the retinal ganglion cells
(RGCs) fail to regenerate their cut axons within the optic nerve interior. This
study was performed to examine whether aging monkey RGCs retain the ability to
regenerate their axons in organ culture and whether axonal regeneration is
associated with specific proteomic profile. Retinal stripes obtained from
marmoset eyes (C. jacchus) were cultured between the day of birth and
adult stages on different substrates like laminin-1, laminin-2, collagen,
matrigel and poly-D-lysine. No neurotrophic factors were added to the medium.
Axonal growth was monitored with microscopy and immunohistochemistry. Onset and
rate of growth was examined with time-lapse videography. Vigorous regeneration
of axons occurred from identifiable morphological types of RGCs throughout all
stages of life, although the numbers of axons decreased with age. Axonal growth
occurred virtually only on laminin-1. Growth correlated with re-expression of
the laminin-1 receptor α6-integrin and sustained
staining for GAP-43 as shown by immunohistochemistry and immunoblotting. At
proteomic level, there is a maturation-dependent change in the protein
immunostaining within the retina. When retinal slices of the same age were
compared, regeneration-specific protein staining included calmodulin, fatty
acid binding protein, alpha-crystallin, IFN-gamma, cyclin-dependent kinase
inhibitor (p21), beta-hemoglobin, 60s-ribosomal protein, GAP-DH and
ADP-ribosylation factor (ARF). To our knowledge these data are the first from
subhuman animals to suggest that axonal regeneration of injured RGCs is
correlated to expression of identifiable proteins within the retina.
