The expression and function of midkine in the vertebrate retina
Version of Record online: 24 JAN 2014
© 2013 The Authors. British Journal of Pharmacology published by John Wiley &. Sons Ltd on behalf of The British Pharmacological Society.
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British Journal of Pharmacology
Special Issue: Themed Section: Midkine. Guest Editors: Takashi Muramatsu and Kenji Kadomatsu
Volume 171, Issue 4, pages 913–923, February 2014
How to Cite
Gramage, E., Li, J. and Hitchcock, P. (2014), The expression and function of midkine in the vertebrate retina. British Journal of Pharmacology, 171: 913–923. doi: 10.1111/bph.12495
- Issue online: 24 JAN 2014
- Version of Record online: 24 JAN 2014
- Manuscript Accepted: 24 OCT 2013
- Manuscript Revised: 21 OCT 2013
- Manuscript Received: 3 JUL 2013
- National Institutes of Health. Grant Numbers: R01 EYO7060, P30 EY07003
- Foundation for the Research to Prevent Blindness
- Müller glia;
The functional role of midkine during development, following injury and in disease has been studied in a variety of tissues. In this review, we summarize what is known about midkine in the vertebrate retina, focusing largely on recent studies utilizing the zebrafish (Danio rerio) as an animal model. Zebrafish are a valuable animal model for studying the retina, due to its very rapid development and amazing ability for functional neuronal regeneration following neuronal cell death. The zebrafish genome harbours two midkine paralogues, midkine-a (mdka) and midkine-b (mdkb), which, during development, are expressed in nested patterns among different cell types. mdka is expressed in the retinal progenitors and mdkb is expressed in newly post-mitotic cells. Interestingly, studies of loss- and gain-of-function in zebrafish larvae indicate that midkine-a regulates cell cycle kinetics. Moreover, both mdka and mdkb are expressed in different cell types in the normal adult zebrafish retina, but after light-induced death of photoreceptors, both are up-regulated and expressed in proliferating Müller glia and photoreceptor progenitors, suggesting an important and (perhaps) coincident role for these cytokines during stem cell-based neuronal regeneration. Based on its known role in other tissues and the expression and function of the midkine paralogues in the zebrafish retina, we propose that midkine has an important functional role both during development and regeneration in the retina. Further studies are needed to understand this role and the mechanisms that underlie it.
This article is part of a themed section on Midkine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-4