Glia are the primary immune cell type in the nervous system. In response to neural infection or trauma they becoming """"""""reactive"""""""", undergoing stereotypical changes in gene expression and morphology. However, the molecular details of glial responses to neural injury or death are poorly understood. We study glial immune functions in Drosophila because it has well-defined glial subtypes that resemble mammalian glia, and it is amenable to genetic analysis. This proposal focuses on the role of Drosophila glia and the newly-identified Drpr receptor in glial engulfment of dead neurons, and glial responses to neural injury in the CNS. Drpr encodes an engulfment receptor essential for glial removal of neuronal cell corpses; the Drpr receptor is also potently transcriptionally upregulated in glia after the axons they ensheath are severed. We will take a molecular genetic approach to understand how Drpr functions in glial responses to neural injury, glial engulfment of injured axons, and additional mechanisms of neuron-glia interactions after neural trauma.
Our specific aims are: 1) Characterize Draper functions in the embryonic CNS: We will define the role for Drpr and specific Drpr receptor isoforms in cell corpse removal and glial morphogenesis in the Drosophila embryonic CNS. 2) Define glial responses to neural injury and roles for Draper in removing injured axons: We will define morphological and molecular changes exhibited by glia in response to neural injury, and determine the requirements for Drpr and glia in the removal of injured axons. 3) Define the cellular and molecular action of Wlds protein: The Wallerian degeneration slow (Wlds) protein protects injured axons from degeneration by unknown mechanisms. We found that Wlds can also spare severed Drosophila axons from degeneration. We will explore Wlds-mediated protection of Drosophila axons, and the consequences of Wlds expression on glial responses to neural injury. Mechanisms of neuron-glia communication after neural injury are likely well-conserved in flies and mice, since Drosophila glia also become reactive and Wlds can protect severed axons in flies. Characterizing genes that regulate neuronal and glial function in response to CNS trauma is essential to identify new avenues for the treatment of CNS injury and neurological disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS053538-04
Application #
7547008
Study Section
Neurodegeneration and Biology of Glia Study Section (NDBG)
Program Officer
Utz, Ursula
Project Start
2006-01-01
Project End
2010-12-31
Budget Start
2009-01-01
Budget End
2009-12-31
Support Year
4
Fiscal Year
2009
Total Cost
$355,022
Indirect Cost
Name
University of Massachusetts Medical School Worcester
Department
Biology
Type
Schools of Medicine
DUNS #
603847393
City
Worcester
State
MA
Country
United States
Zip Code
01655
Cho, Sukhee; Muthukumar, Allie K; Stork, Tobias et al. (2018) Focal adhesion molecules regulate astrocyte morphology and glutamate transporters to suppress seizure-like behavior. Proc Natl Acad Sci U S A 115:11316-11321
Farley, Jonathan E; Burdett, Thomas C; Barria, Romina et al. (2018) Transcription factor Pebbled/RREB1 regulates injury-induced axon degeneration. Proc Natl Acad Sci U S A 115:1358-1363
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Lu, Tsai-Yi; MacDonald, Jennifer M; Neukomm, Lukas J et al. (2017) Axon degeneration induces glial responses through Draper-TRAF4-JNK signalling. Nat Commun 8:14355
Ma, Zhiguo; Stork, Tobias; Bergles, Dwight E et al. (2016) Neuromodulators signal through astrocytes to alter neural circuit activity and behaviour. Nature 539:428-432
He, Jiang; Zhou, Ruobo; Wu, Zhuhao et al. (2016) Prevalent presence of periodic actin-spectrin-based membrane skeleton in a broad range of neuronal cell types and animal species. Proc Natl Acad Sci U S A 113:6029-34
Muthukumar, Allie K; Stork, Tobias; Freeman, Marc R (2014) Activity-dependent regulation of astrocyte GAT levels during synaptogenesis. Nat Neurosci 17:1340-50
Kerr, Kimberly S; Fuentes-Medel, Yuly; Brewer, Cassandra et al. (2014) Glial wingless/Wnt regulates glutamate receptor clustering and synaptic physiology at the Drosophila neuromuscular junction. J Neurosci 34:2910-20
Doherty, Johnna; Sheehan, Amy E; Bradshaw, Rachel et al. (2014) PI3K signaling and Stat92E converge to modulate glial responsiveness to axonal injury. PLoS Biol 12:e1001985
Stork, Tobias; Sheehan, Amy; Tasdemir-Yilmaz, Ozge E et al. (2014) Neuron-glia interactions through the Heartless FGF receptor signaling pathway mediate morphogenesis of Drosophila astrocytes. Neuron 83:388-403

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