Antiviral Drug Ganciclovir Is a Potent Inhibitor of the Proliferation of Müller Glia-Derived Progenitors During Zebrafish Retinal Regeneration.
OBJECTIVE
The purpose of this study was to investigate the effect of the antiviral drug ganciclovir (GCV) on Müller glia dedifferentiation and proliferation and the underlying cellular and molecular mechanisms in adult zebrafish.


METHODS
A Tg(1016tuba1a:GFP) transgenic line was generated to identify injury-induced dedifferentiation of Müller glia. Mechanical retinal damage was induced by a needle-poke injury on the back of the eyes in adult zebrafish. Phosphate-buffered saline or GCV was injected into the vitreous of the eye at the time of injury or through the cornea. The GCV clearance rate from the eye was determined by a reversed-phase HPLC method. Green fluorescent protein (GFP) and bromodeoxyuridine (BrdU) immunofluorescence were used to determine the effect of GCV on retinal regeneration. Cell apoptosis was evaluated by TUNEL staining. Microglia were labeled by vitreous injection of isolectin IB4 conjugates. Quantitative (q)PCR and Western blot analysis were used to determine gene expression in the retina.


RESULTS
Ganciclovir treatment significantly reduced the number of BrdU+ Müller glia-derived progenitor cells (MGPCs) at 4 days post injury. Further analysis showed that GCV had no impact on Müller glia dedifferentiation and the initial formation of MGPCs. Our data indicate that GCV irreversibly inhibited MGPC proliferation likely through a p53-p21(cip1)-dependent pathway. Interestingly, unlike control cells, GCV-treated Müller glia cells were "locked" in a prolonged dedifferentiated state.


CONCLUSIONS
Our study uncovered a novel inhibitory effect of GCV on MGPC proliferation and suggests its potential use as a tool to uncover molecular mechanisms underlying retinal regeneration in zebrafish.
Jiangsu Key Lab of Neuroregeneration Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China.
Shuqiang
S
Zhang
Eye Institute, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China.
Zhaoxia
Z
Mu
Jiangsu Key Lab of Neuroregeneration Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China.
Chunjiao
C
He
College of Biological Science, Nantong University, Nantong, Jiangsu Province, China.
Minmin
M
Zhou
Jiangsu Key Lab of Neuroregeneration Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China.
Dong
D
Liu
Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States.
Xiao-Feng
XF
Zhao
Molecular and Behavioral Neuroscience Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, United States.
Daniel
D
Goldman
Jiangsu Key Lab of Neuroregeneration Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China.
Hui
H
Xu
D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D063928:Ependymoglial Cells / Q000187:drug effects* / Q000502:physiology; D005455:Fluorescent Antibody Technique; D015774:Ganciclovir / Q000494:pharmacology*; D058953:Neural Stem Cells / Q000187:drug effects* / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D012038:Regeneration / Q000187:drug effects*; D012160:Retina / Q000187:drug effects / Q000254:growth & development*; D015027:Zebrafish
D000998:Antiviral Agents; D015774:Ganciclovir