Defense Date

2011

Document Type

Thesis

Degree Name

Master of Science

Department

Anatomy & Neurobiology

First Advisor

Dong Sun

Abstract

Traumatic Brain Injury (TBI) is one of the leading causes of death and disability among young adults and has been a significant field in medical research over the past decades. Intensive studies focusing on how to repair tissue damage resulting from head injuries have discovered that the central nervous system (CNS) retains a regenerative capacity throughout life due to the persistent presence of neural stem/progenitor cells (NS/NPCs) in the neurogenic regions. In the normal brain, cells generated in the subventricular zone (SVZ) migrate along the rostral migratory stream (RMS) to the olfactory bulb and cells in the subgranular zone (SGZ) migrate laterally into the granule cell layer of the dentate gyrus. Directed movement of these NS/NPCs is controlled by a variety of factors, and among them the chemoattractant SDF-1 is of particular importance. Studies have identified that the chemokine SDF-1α and its receptor CXCR4 play an important role in guiding cell migration in many types of cells including NS/NPCs. The current study tested if SDF-1 could be delivered through alginate to attract and guide migration of NS/NPCs and its progeny both in vitro and in vivo. Using a Boyden chamber migration assay, we found SDF-1α either added directly in the medium or incorporated into alginate threads was capable of influencing migration of cultured NS/NPCs in a dose-dependent manner. In the in vivo study, when injected directly into the cerebral cortex, SDF-1  showed limited capability in inducing neuroblasts migration off the normal tract to the site of SDF-1 injection. When SDF-1 was delivered via alginate thread to the focal injury site at 2 days post TBI, significantly increased number of migrating neuroblasts derived from the SVZ was observed around the injury site. Increased expression of SDF-1 receptor CXCR4 was observed in the NS/NPCs in the SVZ and around the injury site following TBI. These data suggest that bioactive SDF-1α can be delivered via alginate thread and exogenous delivery of SDF-1α and its interaction with receptor CXCR4 mediates migration of newly generated neurons from the SVZ to the site of injury following TBI. Collectively, our study indicates that SDF-1α could be utilized as a guidance cue for tissue repair following brain injury.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

May 2011

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