Title
The glial cell modulator ibudilast attenuates neuroinflammation and enhances retinal ganglion cell viability in glaucoma through protein kinase A signaling
Date Issued
01 September 2016
Access level
metadata only access
Resource Type
journal article
Author(s)
University of Montreal
Publisher(s)
Academic Press Inc.
Abstract
Glaucoma is a neurodegenerative disease and the leading cause of irreversible blindness worldwide. Vision deficits in glaucoma result from the selective loss of retinal ganglion cells (RGC). Glial cell-mediated neuroinflammation has been proposed to contribute to disease pathophysiology, but whether this response is harmful or beneficial for RGC survival is not well understood. To test this, we characterized the role of ibudilast, a clinically approved cAMP phosphodiesterase (PDE) inhibitor with preferential affinity for PDE type 4 (PDE4). Here, we demonstrate that intraocular administration of ibudilast dampened macroglia and microglia reactivity in the retina and optic nerve hence decreasing production of proinflammatory cytokines in a rat model of ocular hypertension. Importantly, ibudilast promoted robust RGC soma survival, prevented axonal degeneration, and improved anterograde axonal transport in glaucomatous eyes without altering intraocular pressure. Intriguingly, ocular hypertension triggered upregulation of PDE4 subtype A in Müller glia, and ibudilast stimulated cAMP accumulation in these cells. Co-administration of ibudilast with Rp-cAMPS, a cell-permeable and non-hydrolysable cAMP analog that inhibits protein kinase A (PKA), completely blocked ibudilast-induced neuroprotection. Collectively, these data demonstrate that ibudilast, a safe and well-tolerated glial cell modulator, attenuates gliosis, decreases levels of proinflammatory mediators, and enhances neuronal viability in glaucoma through activation of the cAMP/PKA pathway. This study provides insight into PDE4 signaling as a potential target to counter the harmful effects associated with chronic gliosis and neuroinflammation in glaucoma.
Start page
156
End page
171
Volume
93
Language
English
OCDE Knowledge area
BiologÃa celular, MicrobiologÃa
OftalmologÃa
Scopus EID
2-s2.0-84969627657
PubMed ID
Source
Neurobiology of Disease
ISSN of the container
09699961
Sponsor(s)
We thank Dr. Timothy Kennedy (McGill University) for helpful comments on the manuscript. This work was supported by a grant from the Canadian Institutes of Health Research ( CIHR-VIH-105439 ). N.B. is the recipient of a H. H. Jasper Postdoctoral Research Fellowship in Neurosciences from the Groupe de recherche sur le système nerveux central at the Université de Montreal, and a Postdoctoral Fellowship from the Fonds de recherche Québec-Santé (FRQS) A.D.P. is a Chercheur National of FRQS.
Sources of information:
Directorio de Producción CientÃfica
Scopus