DOI
https://doi.org/10.25772/FDRQ-S750
Defense Date
2013
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Integrative Life Sciences
First Advisor
Robert F. Diegelmann
Abstract
DHEA has been determined to have medically significant activity and is the parent compound to the more active metabolites; 17α-AED, 17β-AED and 17β-AET, which exhibit strong biological activity that has been attributed to androgenic, estrogenic or anti-glucocorticoid activity in vivo and in vitro. This study compared DHEA, 17α-AED, 17β-AED and 17β-AET for their ability to activate the human AR, ER and GR receptors and determine the relative androgenicity, estrogenicity and glucocorticoid activity. The results show that, at the receptor level, these androstene hormones are weak AR and even weaker ER activators. Direct androstene hormone activation of the human AR, ERα, and ERβ may not be essential for their biological function. Similarly, these hormones indirectly activated the human GR receptor; only in the presence of high dexamethasone concentrations. These results underscore the major difference between androstene hormone interactions with these nuclear receptors. 17β-AED and 17α-AED, androstene epimers that produce either survival or death, were utilized to treat T98G Glioblastoma cells. We identified 26 genes oppositely regulated by 17β-AED and 17α-AED to directly affect the cellular life or death decision. Network analysis demonstrated that these 26 genes are essential to regulating three critical Glioblastoma pathways. This report, for the first time, demonstrates that naturally occurring, chemically identical adrenal hormones (17β-AED or 17α-AED) direct a cellular life or death decision through contrasting modulation of identical signaling pathways and core regulators. Chronic pressure ulcers represent a significant health problem and are characterized by hypoxia, bacterial infection, repetitive ischemia/reperfusion and altered cellular and systemic stress responses. Whole genome microarray analysis was utilized in conjunction with IPA® premiere networking software to analyze chronic wound edge tissue. IPA® network analysis identified Ubiquitin C (UBC) as the most significant network. Sixteen (16) ubiquitin C associated genes were identified to be different in the chronic pressure ulcer and normal skin control. Targeted network analysis associated core regulators to 8 UBC associated genes that are unique to chronic pressure ulcers. The identification of these genes will allow the establishment of more effective treatments for Spinal Cord Injury (SCI) patients with chronic pressure ulcers.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
8-13-2013