Anatomy and Neuroscience - Theses

Permanent URI for this collection

http://hdl.handle.net/11343/182

Filters

2015 1
1
Reset filters

Settings
Statistics
Citations
Start date: 2010 × End date: 2019 × Subject: myelin × Author: Hay, Curtis Mackenzie ×

Search Results

Now showing 1 - 1 of 1
  • Item
    Thumbnail Image
    Investigating the role of Gpr62 in oligodendrocyte development and central nervous system myelination
    Hay, Curtis Mackenzie ( 2015)
    Myelination is a highly regulated process in the vertebrate nervous system whereby glial cells wraps axons with insulating myelin in order to allow rapid electrical conduction and metabolic support, a process which is fundamental for proper axon function and survival. Current research in the central nervous system (CNS) has focused on factors affecting oligodendroglial differentiation, yet the molecular interactions that occur post-differentiation between the oligodendrocyte and other CNS cell types during developmental myelination and myelin maintenance are still unclear. This thesis investigates the role the orphan G-protein coupled receptor (GPCR) Gpr62, as it relates to oligodendrocyte development and myelination. First, in silico analysis in conjunction with in situ hybridization showed that Gpr62 is specific to and highly expressed in the CNS, specifically within myelinating oligodendrocytes. Moreover, Gpr62 expression was shown to be regulated by myelin regulatory factor (MyRF), a key transcription factor regulating expression of major myelin genes. Secondly, a germline knockout mouse strain of Gpr62 was investigated. Gpr62 knockout mice showed no significant affect on myelin thickness, myelin gene or protein expression, initiation of myelination, or oligodendrocyte formation relative to their wildtype littermates, all of which were assessed in the developing, adult, and aging brain. An RNA-sequencing analysis revealed few differentially expressed genes between the knockout and wildtype controls, which were not validated in independent cohorts. Interestingly, the RNA- sequencing revealed several differentially expressed genes in close proximity to the Gpr62 locus. Further analysis indicated that these differentially regulated genes proximal to the Gpr62 locus were the result of Sv129-inherited DNA from the ES cells used for targeting, a result with significant implications for other germline knockout lines generated in the same fashion. Finally, forced viral expression of a tagged version of Gpr62 using an AAV virus demonstrated for the first time the cellular localization of the Gpr62 protein, showing expression within the oligodendrocyte extensions and myelin sheath, expressed along the adaxonal space. Collectively, these results indicated that Gpr62 is a novel oligodendrocyte-specific GPCR located along the myelin sheath, yet it is dispensable for myelin development and maintenance. Thus, failure to identify a role for Gpr62 may be the results Gpr62 having a function in the oligodendrocyte outside of developmental myelination. Indeed, the specificity and regulation of Gpr62 expression in oligodendrocytes by MyRF, and its localization within the myelin sheath, suggests Gpr62 may play a role in the oligodendrocyte that has yet to be explored.