Chondroitinase ABC Treatment Enhances Synaptogenesis between Transplant and Host Neurons in Model of Retinal Degeneration

Although recent studies revealed chondroitinase ABC (ChABC), an enzyme that degrades chondroitin sulfate proteoglycans, promotes CNS regeneration in vivo, the usefulness of its application for transplantation is not clear. We investigated if treatment with ChABC can promote synapse formation between...

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Bibliographic Details
Main Authors: Takuya Suzuki, Masayuki Akimoto, Hiroo Imai, Yoshiki Ueda, Michiko Mandai, Nagahisa Yoshimura, Anand Swaroop, Masayo Takahashi
Format: Article
Language:English
Published: SAGE Publishing 2007-05-01
Series:Cell Transplantation
Online Access:https://doi.org/10.3727/000000007783464966
Description
Summary:Although recent studies revealed chondroitinase ABC (ChABC), an enzyme that degrades chondroitin sulfate proteoglycans, promotes CNS regeneration in vivo, the usefulness of its application for transplantation is not clear. We investigated if treatment with ChABC can promote synapse formation between graft and host neurons following retinal transplantation. Dissociated retinal cells were prepared from neonatal Nrl-GFP transgenic mice in which rod photoreceptors and their progenitor cells are labeled with GFP. Each cell suspension with or without ChABC (Nrl/ChABC group and Nrl group, respectively) was injected subretinally into the eyes of mice following chemically induced photoreceptor degeneration. The survival and functional integration of the transplanted photoreceptors were examined by histologically and electrophysio-logically. Up to 4 weeks after transplantation, almost all the grafted GFP+ photoreceptor cells were widely distributed at the outer margin of the host retina where the photoreceptor layer was located originally. In the Nrl/ChABC group, 33.6% of the GFP+ photoreceptors elaborated neurites horizontally or vertically, and 4.6% elaborated neurites toward the retina. These neurites extended over the glial seal at the graft–host interface, and established synaptic contacts with neurons in the host retina as determined by confocal microscopy and three-dimensional analysis. Although 30.7% cells (p = 0.68) elaborated neurites in the Nrl group, only 1.2% cells (p < 0.05) projected neurites towards the host tissue and synaptic contacts were rare. Our results illustrate the potential utility of ChABC for enhancing synaptogenesis between transplanted neurons and host retina.
ISSN:0963-6897
1555-3892