601B Life Sciences Center
A myelinated axon is a highly specialized structure that forms as the result of instructive, contact-dependent signaling during development, between the axon and the myelinating glial cell – the Schwann cell in the peripheral nervous system (PNS), the oligodendrocyte in the central nervous system (CNS). Axons regulate gliogenesis and promote the formation of the myelin sheath that spirals around axons. Glial cells, in turn, promote the survival of neurons, and further organize the entire length of the axon into a series of specialized domains that can be distinguished by their structure, molecular composition and physiological function. Axo-glial interactions and subsequent domain organization are crucial to axon function and integrity, as well as for efficient and rapid propagation of action potentials by saltatory conduction. Indeed, a disruption in these interactions results in conduction block and axonal degeneration, and may contribute to age-related changes in axon conduction. The elucidation of the molecular mechanisms that regulate the axo-glial interactions therefore has significant clinical implications.
Work in my lab focuses on cell adhesion molecules (the Nectin-like proteins) whose restricted and complementary axonal and glial pattern of expression regulates axo-glial interactions during myelination. We use an in vitro neuron-glia co-culture myelinating system in conjunction with biomolecular techniques, as well as in vivo mouse models, to: a) determine which domains of the Necl proteins are required to their function, b) address the significance of the Necls' interactions with polarity proteins with regard to PNS and CNS myelination and, c) characterize how the Necl proteins regulate the signaling pathways required for myelination.
B.S. in Natural Sciences, Université Paul Sabatier, Toulouse, France, 1986.
B.S. in Biochemistry & Molecular Biology, Université Paul Sabatier, Toulouse, France, 1986.
M.S. in Pharmacology & Molecular Toxicology, Université Paul Sabatier, Toulouse, France, 1987.
Ph.D. in Developmental Neurobiology, Université Paul Sabatier, Toulouse, France, 1991.
Maurel P., and Salzer J.L. Basal lamina deposition by Schwann cells requires axonal contact and PI 3-kinase activity. In preparation.
Einheber, S., Meng, X., Rubin, M., Lam, I., Mohandas, N., An, X., Shrager, P., Kissil, J., Maurel, P., and Salzer, J.L. The 4.1B cytoskeletal protein regulates the domain organization and sheath thickness of myelinated axons. Glia 61:240-253 (2013).
Yang, D.P., Kim, J., Syed, N., Tung, Y.J., Bhaskaran, A., Mindos, T., Mirsky, R., Jessen, K.R., Maurel, P., Parkinson, D.B., and Kim, H.A. p38 MAPK activation promotes denervated Schwann cell phenotype and functions as a negative regulator of Schwann cell differentiation and myelination. J. Neurosci. 32: 7158-7168 (2012).
Syed, N., Reddy, K., Yang, D.P., Taveggia, C., Salzer, J.L., Maurel, P., and Kim, H.A. Soluble neuregulin-1 has bifunctional, concentration-dependent effects on Schwann cell myelination. J. Neurosci. 30: 6122-6131 (2010).
Kim, H.A., and Maurel P. Primary Schwann cell cultures. In: Protocols for neural cell culture, 4th Edition (L. Doering ed) Totowa: Humana Press Inc/Springer media. (2010).
Maurel P., Einheber S., Galinska J., Thaker P., Lam I., Rubin M.B., Scherer S.S., Murakami Y., Gutmann D.H., and Salzer J.L. Nectin-like proteins mediate axon-Schwann cell interactions along the internode and are essential for myelination. J. Cell Biol. 178:861-874 (2007).
Koticha D., Maurel P., Zanazzi G., Kane-Goldsmith N., Basak S., Babiarz J., Salzer J.L., and Grumet M. Neurofascin interactions play a critical role in clustering sodium channels, ankyrin G and ßIV spectrin at peripheral nodes of Ranvier. Dev. Biol. 293:1-12 (2006).
Melendez-Vasquez C., Carey D.J., Zannazi G., Reizes O, Maurel P., and Salzer J.L. Differential expression of proteoglycans at central and peripheral nodes of Ranvier. Glia 52:301-305 (2005).
Popp S., Maurel P., Andersen J.S., and Margolis R.U. Developmental changes of aggrecan, versican and neurocan in the retina and optic nerve. Experimental Eye Research 79:351-356 (2004).
Popp S., Andersen J.S., Maurel P., and Margolis R.U. Localization of aggrecan and versican in the developing rat central nervous system. Dev. Dynam. 224:143-149 (2003).
Maurel P., and Salzer J.L. Axonal regulation of Schwann cell proliferation and survival and the initial events of myelination requires PI 3-kinase activity. J. Neurosci. 20:4635-4645 (2000).
Lemire J.M., Braun K.R., Maurel P., Kaplan E.D., Schwartz S.M., and Wight T.N. Versican/PG-M isoforms in vascular smooth muscle cells. Arterioscler. Throm. Vas. 19:1630-1639 (1999).
Milev P., Maurel P., Chiba A., Mevissen M., Popp S., Yamaguchi Y., Margolis R.K., and Margolis R.U. Differential regulation of expression of hyaluronan-binding proteoglycans in developing brain: aggrecan, versican, neurocan and brevican. Biochem. Bioph. Res. Co. 247:207-212 (1998).
Margolis R.K., Rauch U., Maurel P., and Magolis R.U. Neurocan and Phosphacan: two major nervous tissue-specific chondroitin sulfate proteoglycans. Persp. Dev. Neurobiol. 3:273-290 (1996).
Milev P., Maurel P., Häring M., Margolis R.K., and Margolis R.U. TAG-1/axonin-1 is a high-affinity ligand of neurocan, phosphacan/proteine tyrosine phosphatase-ζ/ß and N-CAM. J. Biol. Chem. 271:15716-15723 (1996).
Engel M., Maurel P., Margolis R.U., and Margolis R.K. Chondroitin sulfate proteoglycans in the developing central nervous system. I: Cellular sites of synthesis of neurocan and phosphacan. J. Comp. Neurol. 366:34-43 (1996).
Maurel P., Meyer-Puttlitz B., Flad M., Margolis R.U., and Margolis R.K. Nucleotide sequence and molecular variants of rat receptor-type proteine tyrosine phosphatase-ζ/ß. DNA Sequence 5:323-328 (1995).
Maurel P., Rauch U., Flad M., Margolis R.K., and Margolis R.U. Phosphacan, a chondroitin sulfate proteoglycan of brain that interacts with neurons and neural cell-adhesion molecules, is an extracellular variant of a receptor-type proteine tyrosine phosphatase. P. Natl. Acad. Sci. USA, 91:2512-2516 (1994).
Rauch U., Karthikeyan L., Maurel P., Margolis R.U., and Margolis R.K. Cloning and primary structure of neurocan, a developmentally regulated, aggregating chondroitin sulfate proteoglycan of brain. J. Biol. Chem., 267:19536-19547 (1992).
Karthikeyan L., Maurel P., Margolis R.K., and Margolis R.U. Cloning of a major heparan sulfate proteoglycan from brain and identification as the rat form of glypican. Biochem. Bioph. Res. Co., 188:395-401 (1992).