| dc.identifier.uri | http://hdl.handle.net/11401/76521 | |
| dc.description.sponsorship | This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree. | en_US |
| dc.format | Monograph | |
| dc.format.medium | Electronic Resource | en_US |
| dc.language.iso | en_US | |
| dc.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dc.type | Dissertation | |
| dcterms.abstract | Oligodendrocyte progenitor cells (OPCs) are characterized by their capacity for proliferation, migration, and maturation into myelinating oligodendrocytes. Among the known molecular mechanisms that regulate OPC development are 1) the extracellular matrix (ECM) protein laminin that is known to regulate OPC development as it is required for timely oligodendrocyte differentiation and myelination, and 2) an oligodendroglial laminin receptor, dystroglycan, which regulates oligodendrocyte morphology and maturation. ECM proteins and receptors can be remodeled by proteolytic enzymes known as the matrix metalloproteinases (MMPs), but little is known regarding these events and their consequent functions in CNS development and regeneration. While the laminin-dystroglycan adhesion complex appears to be important for oligodendrocyte development, it remains unknown whether proteolytic remodeling of this complex regulates its function and if it influences oligodendroglial development. Several MMPs have been shown to cleave laminins and dystroglycan in other cell types, suggesting that these proteins may undergo MMP-mediated proteolysis. Furthermore, oligodendroglia express at least 17 different members of the MMP family, and their patterns of expression change during differentiation, suggesting that oligodendroglia utilize these enzymes during development. In this thesis project, I investigated whether oligodendroglial dystroglycan is proteolytically processed by MMPs in the developing brain and whether such processing plays a role in oligodendroglial development. I found that dystroglycan is cleaved in the postnatal cerebral cortex and that decreasing levels of dystroglycan cleavage correlate with developmental myelination. Similarly, OPCs in culture exhibit dystroglycan cleavage, which substantially decreases with oligodendroglial differentiation and appears to be promoted by laminin-211 but not laminin-111. Furthermore, while dystroglycan processing is due to metalloproteinase activity, it is not mediated by the metalloproteinases that cleave dystroglycan in other tissues (MMPs-2 and -9). Blocking dystroglycan cleavage using metalloproteinase inhibitors resulted in decreased OPC proliferation, where a transient G0/G1 arrest in cell cycle progression correlated with decreased expression of cyclin-cdk complex proteins. Inversely, the expression of a dystroglycan construct designed to mimic cleaved dystroglycan resulted in an increased trend in OPC proliferation. These results suggest that dystroglycan cleavage is involved in OPC proliferation and that appropriate dystroglycan remodeling may contribute to generating appropriate numbers of OPCs required for normal myelination. In other tissues, it is known that MMP-7 cleaves the dystroglycan ligand laminin. I found that exogenous MMP-7 impedes normal oligodendrocyte differentiation while MMP-7 inhibition promotes it, suggesting that MMP-7 is an inhibitor of myelination. Together, these studies demonstrate that MMP activity is important for multiple steps in oligodendroglial development, including OPC proliferation and oligodendrocyte maturation. | |
| dcterms.available | 2017-09-20T16:50:32Z | |
| dcterms.contributor | Colognato, Holly A | en_US |
| dcterms.contributor | Cao, Jian | en_US |
| dcterms.contributor | Ge, Shaoyu | en_US |
| dcterms.contributor | Crawford, Howard | en_US |
| dcterms.contributor | Czaplinski, Kevin. | en_US |
| dcterms.creator | Leiton, Cindy Viviana | |
| dcterms.dateAccepted | 2017-09-20T16:50:32Z | |
| dcterms.dateSubmitted | 2017-09-20T16:50:32Z | |
| dcterms.description | Department of Molecular and Cellular Pharmacology. | en_US |
| dcterms.extent | 125 pg. | en_US |
| dcterms.format | Application/PDF | en_US |
| dcterms.format | Monograph | |
| dcterms.identifier | http://hdl.handle.net/11401/76521 | |
| dcterms.issued | 2014-12-01 | |
| dcterms.language | en_US | |
| dcterms.provenance | Made available in DSpace on 2017-09-20T16:50:32Z (GMT). No. of bitstreams: 1
Leiton_grad.sunysb_0771E_11715.pdf: 4744912 bytes, checksum: ee98321a2fbcd09d6a1a3e98dedbaeeb (MD5)
Previous issue date: 1 | en |
| dcterms.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dcterms.subject | Dystroglycan, laminin, MMP, oligodendrocyte, OPC, Proteolysis | |
| dcterms.subject | Neurosciences | |
| dcterms.title | The Role of Matrix Metalloproteinases in Oligodendrocyte Development | |
| dcterms.type | Dissertation | |
