Functional genomic screening identifies dual leucine zipper kinase as a key mediator of retinal ganglion cell death.

Abstract

Glaucoma, a major cause of blindness worldwide, is a neurodegenerative optic neuropathy in which vision loss is caused by loss of retinal ganglion cells (RGCs). To better define the pathways mediating RGC death and identify targets for the development of neuroprotective drugs, we developed a high-throughput RNA interference screen with primary RGCs and used it to screen the full mouse kinome. The screen identified dual leucine zipper kinase (DLK) as a key neuroprotective target in RGCs. In cultured RGCs, DLK signaling is both necessary and sufficient for cell death. DLK undergoes robust posttranscriptional up-regulation in response to axonal injury in vitro and in vivo. Using a conditional knockout approach, we confirmed that DLK is required for RGC JNK activation and cell death in a rodent model of optic neuropathy. In addition, tozasertib, a small molecule protein kinase inhibitor with activity against DLK, protects RGCs from cell death in rodent glaucoma and traumatic optic neuropathy models. Together, our results establish a previously undescribed drug/drug target combination in glaucoma, identify an early marker of RGC injury, and provide a starting point for the development of more specific neuroprotective DLK inhibitors for the treatment of glaucoma, nonglaucomatous forms of optic neuropathy, and perhaps other CNS neurodegenerations.

• Authors: Derek S Welsbie, Zhiyong Yang, Yan Ge, Katherine L Mitchell, Xinrong Zhou, Scott E Martin, Cynthia A Berlinicke, Laszlo Hackler Jr, John Fuller, Jie Fu, Li-hui Cao, Bing Han, Douglas Auld, Tian Xue, Syu-ichi Hirai, Lucie Germain, Caroline Simard-Bisson, Richard Blouin, Judy V Nguyen, Chung-ha O Davis, Raymond A Enke, Sanford L Boye, Shannath L Merbs, Nicholas Marsh-Armstrong, William W Hauswirth, Aaron DiAntonio, Robert W Nickells, James Inglese, Justin Hanes, King-Wai Yau, Harry A Quigley, Donald J Zack
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 110 Issue 10 Pg. 4045-50 (Mar 05 2013) ISSN: 1091-6490 [Electronic] United States
• PMID: 23431148 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Piperazines
• Protein Kinase Inhibitors
• tozasertib
• MAP Kinase Kinase Kinases
• mitogen-activated protein kinase kinase kinase 12

Topics

• Animals
• Cell Death (genetics, physiology)
• Cell Survival (drug effects, genetics, physiology)
• Cells, Cultured
• Disease Models, Animal
• Down-Regulation
• Glaucoma (drug therapy, etiology)
• Humans
• MAP Kinase Kinase Kinases (antagonists & inhibitors, genetics, physiology)
• Male
• Mice
• Optic Nerve Diseases (etiology, pathology)
• Optic Nerve Injuries (drug therapy, enzymology, pathology)
• Piperazines (pharmacology)
• Protein Kinase Inhibitors (pharmacology)
• RNA Interference
• Rats
• Rats, Wistar
• Retinal Ganglion Cells (drug effects, enzymology, pathology)
• Signal Transduction
• Up-Regulation