Expression of nervous tissue–specific proteoglycans in the retina after transplantation of neural precursor cells.

Abstract

Abstract: : Purpose:Nervous tissue–specific proteoglycans are suggested to play important roles in cell adhesion and proliferation, differentiation, axonal growth, and axonal pathfinding during development of the nervous system. After brain or retinal injury, nervous tissue–specific proteoglycans are upregurated in the glial scar. This study was conducted in an attempt to investigate the expression of nervous tissue specific proteoglycan in retina after transplantation of neural precursor cells (NPCs). Method: N–methyl–D–aspartate (NMDA; 4mM, 5µl) was injected into the intravitreal space of adult rat to induce retinal cell death. NPCs were prepared from the telencephalic neuroepithelium of EGFP (enhanced green fluorescence protein) transgenic mice on embryonic day 14. Cell suspension (5x10⁵ cells) was injected into intravitreal space of NMDA–treated eyes. At 1, 2 or 4 week after transplantation, sections were prepared for immunohistochemistry of nervous tissue–specific proteoglycans (neurocan, phosphacan, and neuroglycan C). Results: The expression of nervous tissue–specific proteoglycans is abundant in developing rat retina, but is only faint in mature retina. These proteoglycans were expressed in inner plexiform layer and outer plexiform layer in the host mature retina with incorporation of NPCs. Furthermore the neurites of some incorporated NPCs expressed these proteoglycans. Conclusion: We demonstrated that the upregulated expression of nervous tissue specific proteoglycan in the retina after transplantation of NPCs. The results suggest that the proteoglycan may play a role in differentiation and axonal growth of NPCs in the host retina.

Keywords: transplantation • proteoglycans/glycosaminoglycans • immunohistochemistry