Greece | 2002 | Ph.D.
University of Crete
Greece | 1997 | M.S.
University of Crete
Greece | 1993 | B.S.
Downers Grove, IL
Demyelinating diseases of the central and the peripheral nervous system
I am interested in the biology of myelinating glial cells i.e. oligodendrocytes in the CNS and Schwann cells in the PNS that produce the myelin sheath, which is the lipid-rich membrane that wraps around the axons and ensures the saltatory propagation of the neuronal action potential. In demyelinating diseases of the central nervous system (CNS) such as multiple sclerosis (MS) and leukodystrophies i.e. the genetic disorders affecting the white matter in the CNS, as well as in demyelinating diseases of the peripheral nervous system (PNS) such as demyelinating Charcot-Marie-Tooth (CMT) diseases the myelin sheath is significantly damaged, leading to motor and sensory dysfunction causing serious neurological deficits. In my lab, we are using genetic mouse models and primary neural cell culture systems to investigate the cellular and molecular mechanisms of myelin and neuronal damage that occurs in CNS and PNS demyelinating diseases as well as to identify new molecular targets to promote myelin repair and restore neuronal function in these devastating neurological diseases.
We have developed several mouse models for CNS neurodegenerative diseases: the Aspanur7 mouse, which is an authentic model for the fatal childhood leukodystrophy Canavan disease and has helped uncover critical information regarding the pathogenesis of this disease (Traka et al., J Neurosci. 2008); the Wdr81nur5 mouse model for cerebellar ataxia, mental retardation and quadrupedal locomotion syndrome (CAMRQ2; Traka et al., J Neurosci. 2013); the diphtheria-toxin A chain (DTA) mouse model that allows for the tamoxifen-induced ablation of oligodendrocytes throughout the CNS. Our studies on the DTA mouse have revealed that the CNS has a robust innate capacity to repair myelin damage and restore neuronal function upon inducing oligodendrocyte cell loss (Traka et al., Brain 2010). Moreover, we recently used the DTA mouse to show that oligodendrocyte death might be the primary trigger of MS (Traka et al., Nat Neurosci. 2016 ; Nature Reviews Neuroscience 17, 76, 2016). This finding is of fundamental importance to our understanding of the origins of the autoimmunity that characterizes MS and it might lead to the development of new therapeutic approaches to the treatment of this devastating disease in the future.
Downers Grove, IL
College of Graduate Studies - IL
Biomedical Sciences (M.A.)
Biomedical Sciences (M.B.S.)
Project I: Mechanisms of demyelination and remyelination in adult-onset demyelinating diseases
To investigate the demyelination and remyelination processes in the central nervous system (CNS), we have developed the DTA mouse model that specifically targets the ablation of mature myelin-forming oligodendrocytes by activating the expression of the diphtheria toxin A subunit (DT-A) expression in these cells through tamoxifen injections into young adult PLP/CreERT;ROSA26-eGFP-DTA (DTA) mice. The tamoxifen-treated DTA mice develop severe neurological symptoms by 5 weeks post-activation (peak of disease) that correlate with widespread oligodendrocyte loss and demyelination in the CNS. Strikingly, these animals fully recover from their motor and physiological defects and display extensive oligodendrocyte replenishment and widespread remyelination of the demyelinated areas by adult oligodendrocyte progenitor cells (OPCs) at approximately 10 weeks post-activation. Overall, the DTA mouse model shows that the CNS has a robust reparative capacity to remyelinate. Interestingly, after the tamoxifen-treated DTA mice recovered from oligodendrocyte loss, they developed a secondary, lethal disease that correlates with increased demyelination, axonal degeneration and T cell inflammation of the CNS staring at approximately 40 weeks post-activation. At this late-onset disease time point, focal inflammatory demyelinating lesions were found in various white matter–rich CNS areas of the tamoxifen-treated DTA mice, which progress to extensive myelin loss throughout the CNS by 1 year after injection. Our findings suggest that primary oligodendrocyte death is sufficient to trigger an adaptive immune response against myelin suggesting that MS may develop secondary to intrinsic myelin damage (Traka et al., Nat Neurosci. 2016; Highlight in Nature Reviews Neuroscience 17, 76, 2016). In this project, we are using the DTA mouse model to investigate the mechanisms of pathogenesis and repair in adult-onset CNS demyelinating diseases such as MS, which is the most common neurological disorder in young adults.
We are also using the DTA mouse model to study the impact of the Schwann cell loss in the PNS, since the tamoxifen-treated DTA mice show loss of the myelinating Schwann cells that leads to mild peripheral nerve demyelination causing associated neurological problems by 3 weeks post-activation and they significantly recover from their PNS defects by 10 weeks post-activation. Therefore, the DTA mouse model is ideal for studying the specific effects of Schwann cell loss on myelin and axonal integrity and for dissecting the molecular pathways that are critical for the demyelination and remyelination processes in the PNS.
Project II: Pathogenesis of Canavan disease
Autosomal recessive mutations of the aspartoacylase (ASPA) gene in humans cause the fatal childhood leukodystrophy Canavan disease (CD), which involves the spongy degeneration of the CNS white matter. Affected individuals suffer from mental retardation, weakness, blindness, and functional disability, and most die by the age of five. We have identified and thoroughly characterized the N-ethyl-N-nitrosourea (ENU)-induced nonsense mutation of the mouse Aspa gene, Aspanur7, which causes an early-onset and progressive spongy degeneration of the myelin sheath in the CNS white matter that strikingly resembles CD. ASPA has been known to catalyze the hydrolysis of the most abundant amino acid in the brain, N-acetylaspartate (NAA), to acetate and aspartic acid in mature oligodendrocytes. Although the NAA-derived acetate is being used for the myelin lipid synthesis, there is not yet a clear link between the deficient NAA hydrolysis and the myelin degeneration observed in CD. In this project, we are using genetic mouse models and myelinating co-cultures of the oligodendrocyte progenitor cells (OPCs) with the retinal ganglion cell neurons (RGCs) to investigate the role of ASPA in CNS myelination and elucidating the downstream effectors of the ASPA activity in mature oligodendrocytes, which is critical for our efforts to develop therapeutic targets that promote myelin repair in this disease.
Traka M. The DTA Mouse Model for Oligodendrocyte Ablation and CNS Demyelination. Methods Mol Biol. 2019;1936:295-310. doi: 10.1007/978-1-4939-9072-6_17. PubMed PMID: 30820906.
Elbaz B, Traka M, Kunjamma RB, Dukala D, Brosius Lutz A, Anton ES, Barres BA, Soliven B, Popko B. Adenomatous polyposis coli regulates radial axonal sorting and myelination in the PNS. Development. 2016 Jul 1;143(13):2356-66. doi: 10.1242/dev.135913. Epub 2016 May 25. PubMed PMID: 27226321; PubMed Central PMCID: PMC4958326.
Traka M, Podojil JR, McCarthy DP, Miller SD, Popko B. Oligodendrocyte death results in immune-mediated CNS demyelination. Nat Neurosci. 2016 Jan;19(1):65-74. doi: 10.1038/nn.4193. Epub 2015 Dec 14. PubMed PMID: 26656646; PubMed Central PMCID: PMC4837900.
Traka M, Millen KJ, Collins D, Elbaz B, Kidd GJ, Gomez CM, Popko B. WDR81 is necessary for purkinje and photoreceptor cell survival. J Neurosci. 2013 Apr 17;33(16):6834-44. doi: 10.1523/JNEUROSCI.2394-12.2013. PubMed PMID: 23595742; PubMed Central PMCID: PMC6618862.
Ghadge GD, Wollmann R, Baida G, Traka M, Roos RP. The L-coding region of the DA strain of Theiler's murine encephalomyelitis virus causes dysfunction and death of myelin-synthesizing cells. J Virol. 2011 Sep;85(18):9377-84. doi: 10.1128/JVI.00178-11. Epub 2011 Jul 13. PubMed PMID: 21752920; PubMed Central PMCID: PMC3165738.
Kim HJ, Miron VE, Dukala D, Proia RL, Ludwin SK, Traka M, Antel JP, Soliven B. Neurobiological effects of sphingosine 1-phosphate receptor modulation in the cuprizone model. FASEB J. 2011 May;25(5):1509-18. doi: 10.1096/fj.10-173203. Epub 2011 Jan 19. PubMed PMID: 21248243; PubMed Central PMCID: PMC3079302.
Traka M, Arasi K, Avila RL, Podojil JR, Christakos A, Miller SD, Soliven B, Popko B. A genetic mouse model of adult-onset, pervasive central nervous system demyelination with robust remyelination. Brain. 2010 Oct;133(10):3017-29. doi: 10.1093/brain/awq247. Epub 2010 Sep 17. PubMed PMID: 20851998; PubMed Central PMCID: PMC4415057.
Saadat L, Dupree JL, Kilkus J, Han X, Traka M, Proia RL, Dawson G, Popko B. Absence of oligodendroglial glucosylceramide synthesis does not result in CNS myelin abnormalities or alter the dysmyelinating phenotype of CGT-deficient mice. Glia. 2010 Mar;58(4):391-8. doi: 10.1002/glia.20930. PubMed PMID: 19705459; PubMed Central PMCID: PMC2807477.
Howng SY, Avila RL, Emery B, Traka M, Lin W, Watkins T, Cook S, Bronson R, Davisson M, Barres BA, Popko B. ZFP191 is required by oligodendrocytes for CNS myelination. Genes Dev. 2010 Feb 1;24(3):301-11. doi: 10.1101/gad.1864510. Epub 2010 Jan 15. PubMed PMID: 20080941; PubMed Central PMCID: PMC2811831.
Traka M, Wollmann RL, Cerda SR, Dugas J, Barres BA, Popko B. Nur7 is a nonsense mutation in the mouse aspartoacylase gene that causes spongy degeneration of the CNS. J Neurosci. 2008 Nov 5;28(45):11537-49. doi: 10.1523/JNEUROSCI.1490-08.2008. PubMed PMID: 18987190; PubMed Central PMCID: PMC2613291.
Traka M, Seburn KL, Popko B. Nmf11 is a novel ENU-induced mutation in the mouse glycine receptor alpha 1 subunit. Mamm Genome. 2006 Sep;17(9):950-5. doi: 10.1007/s00335-006-0020-z. Epub 2006 Sep 8. PubMed PMID: 16964444.
Soares S, Traka M, von Boxberg Y, Bouquet C, Karagogeos D, Nothias F. Neuronal and glial expression of the adhesion molecule TAG-1 is regulated after peripheral nerve lesion or central neurodegeneration of adult nervous system. Eur J Neurosci. 2005 Mar;21(5):1169-80. doi: 10.1111/j.1460-9568.2005.03961.x. PubMed PMID: 15813926.
Traka M, Goutebroze L, Denisenko N, Bessa M, Nifli A, Havaki S, Iwakura Y, Fukamauchi F, Watanabe K, Soliven B, Girault JA, Karagogeos D. Association of TAG-1 with Caspr2 is essential for the molecular organization of juxtaparanodal regions of myelinated fibers. J Cell Biol. 2003 Sep 15;162(6):1161-72. doi: 10.1083/jcb.200305078. PubMed PMID: 12975355; PubMed Central PMCID: PMC2172849.
Traka M, Dupree JL, Popko B, Karagogeos D. The neuronal adhesion protein TAG-1 is expressed by Schwann cells and oligodendrocytes and is localized to the juxtaparanodal region of myelinated fibers. J Neurosci. 2002 Apr 15;22(8):3016-24. doi: 20026306. PubMed PMID: 11943804; PubMed Central PMCID: PMC6757518.
Member, Society for Neuroscience
Title: Investigating the molecular basis of Canavan disease
Agency: National Institutes of Health (NIH-1R21NS083042-01A1)
Principal Investigator: Maria Traka
Title:Development of an in vitro approach to identify molecular pathways of Canavan disease
Agency: National Tay-Sachs & Allied Diseases Association (NTSAD)
Principal Investigator: Maria Traka
Myelin Repair Foundation (MRF) Award for the Best Scientific Contribution at the MRF annual meeting
National Multiple Sclerosis Society (NMSS) Postdoctoral Fellowship Award
International Society of Neurochemistry (ISN) Fellowship