Loading...
Effects of the Cerebral Palsy-associated Mutation RhoB (S73F) in Cortical Development
Rajavong, Kathleen
Rajavong, Kathleen
Citations
Altmetric:
Genre
Thesis/Dissertation
Date
2022
Advisor
Committee member
Group
Department
Cell Biology
Permanent link to this record
Collections
Research Projects
Organizational Units
Journal Issue
DOI
http://dx.doi.org/10.34944/dspace/7646
Abstract
Cerebral palsy (CP) as a neurodevelopmental disorder that affects individuals’ movement, posture, and balance and occurs in every 2-3 out of 1,000 live births. Symptoms of CP can include seizures, hydrocephalus, impairment of the limbs, and learning disabilities. External contributors to CP are well known, but there are 80% of CP cases are idiopathic and in which no brain injury is reported. Recently, several genetic studies have shown that deleterious de novo mutations in CP patients may be implicated in CP pathogenesis. One such potentially deleterious de novo mutation of RhoB was identified in two CP patients. RhoB encodes for RHOB protein, a Rho GTPase that regulates the actin cytoskeleton. Biochemical and structural analyses of RhoB (S73F) protein suggested that the RhoB mutation generates a hyperactive form of RhoB. However, how the RhoB (S73F) protein may interfere with brain development and can contribute to CP is unknown. To determine whether RhoB (S73F) expression affects cortical development, we used in utero electroporations in mice to study the effect of RhoB (S73F) expression on cellular morphology, polarity, migration, and Golgi localization in the embryonic mouse model at E15.5 and P0, comparing it to a RhoB overexpression model as well as control. To address changes in cell morphology, we examined the cell size, shape, and volume of RhoB expressing cells using Imaris software. We show that RhoB overexpression and RhoB (S73F) expression cause detrimental changes in cell shape, polarity, and neuritogenesis. Furthermore, RhoB (S73F) expressing cells migrate less compared to RhoB overexpressing cells and control. Interestingly, we found that RhoB (S73F) expressing cells that did not migrate away from the ventricular surface still became neurons. To determine the effect of RhoB (S73F) expression on the subcellular environment, we examined the localization of the Golgi apparatus, and found the Golgi to be mislocalized and fragmented when RhoB (S73F) was expressed. Overall, this study shows that overexpression of RhoB is sufficient to cause changes in cell morphology, polarity, migration, and subcellular localization of the Golgi. Importantly, expression of RhoB (S73F) is distinct and unique from RhoB overexpression, causing more severe changes in cell size, shape, polarity, cell process number, and Golgi localization that result in failed neuronal migration. This data suggests the potential for genetic mutations to enact changes within the structure and function of cortical cells, which may contribute to the pathogenesis of CP.
Description
Citation
Citation to related work
Has part
ADA compliance
For Americans with Disabilities Act (ADA) accommodation, including help with reading this content, please contact scholarshare@temple.edu