PhD, University of Cincinnati, 2019, Medicine: Molecular, Cellular and Biochemical Pharmacology

In this dissertation, the functional role of Tumor susceptibility gene (Tsg101) in the regulation of physiological cardiac hypertrophy and endotoxin-induced cardiac dysfunction was explored. Development of physiological cardiac hypertrophy has primarily been ascribed to the insulin-like growth factor 1 (IGF-1) and its receptor, IGF-1R, and subsequent activation of the Akt pathway. However, regulation of endosome-mediated recycling and degradation of IGF-1R during physiological hypertrophy has not been investigated. Furthermore, cardiac mitochondrial damage and subsequent inflammation are hallmarks of endotoxin-induced myocardial depression. Activation of the Parkin/PINK1 pathway has been shown to promote autophagy of damaged mitochondria (mitophagy) and protect from endotoxin-induced cardiac dysfunction. Tsg101 has been demonstrated to play diverse roles in the cell including virus budding, cytokinesis, transcriptional regulation, endosomal recycling of receptors and activation of autophagic flux. Hence, the first goal of this dissertation was to elucidate the role of Tg101 in endosome-mediated recycling of IGF-1R in physiological cardiac remodeling. The second goal of this dissertation was to investigate whether Tsg101 regulates mitophagy and thus contribute to endotoxin-caused myocardial dysfunction. Firstly, in a physiological hypertrophy model of treadmill-exercised mice, we observed that levels of Tsg101 were dramatically elevated in the heart, compared to sedentary controls. To determine the role of Tsg101 on physiological hypertrophy, we generated a transgenic mouse model with cardiac-specific overexpression of Tsg101. These transgenic (TG) mice exhibited physiological cardiac hypertrophy at 8 weeks, evidenced by significant enhancement of cardiac function without fibrosis, increased total and membrane levels of IGF-1R, as well as Akt activation, compared to wild-types. Mechanistically, we identified that Tsg101 interacted with FIP3 and IGF-1R, thereby s (open full item for complete abstract)

Committee: Guochang Fan Ph.D. (Committee Chair); Charles Caldwell Ph.D. (Committee Member); Terence Kirley Ph.D. (Committee Member); Evangelia Kranias Ph.D. (Committee Member); Jack Rubinstein M.D. (Committee Member) Subjects: Physiological Psychology

Doctor of Philosophy, The Ohio State University, 2017, Ohio State University Nutrition

Green tea extract (GTE) protects against nuclear factor kappa B (NFkappaB)-mediated liver inflammation during nonalcoholic steatohepatitis (NASH). However, the mechanisms by which GTE exerts its antiinflammatory activities during NASH are unclear. There are several potential pathways and environmental conditions that mediate hepatic NFkappaB activation during NASH, including intracellular oxidative stress that is downregulated by nuclear factor E2-related factor 2 (Nrf2)-dependent antioxidant defenses, as well as the extracellular receptor-mediated pathways toll-like receptor 4 (TLR4) and tumor necrosis factor receptor 1 (TNFR1). Therefore, this dissertation aimed to define the involvement of these pathways in relation to antiinflammatory activities of GTE on hepatic NFkappaB activation during NASH. The central hypothesis was that GTE suppresses hepatic NFkappaB activation by increasing the activities of Nrf2, and by decreasing TLR4- and TNFR1-mediated signaling. Contrary to the hypothesis, studies in Nrf2-knockout mice demonstrated that GTE exerts its antiinflammatory activities against NFkappaB activation during NASH in an Nrf2-independent manner. Studies in wild-type mice that were fed with low-fat (LF) or high-fat (HF) diet containing 0 or 2% GTE demonstrated that GTE lowers NFkappaB-dependent inflammatory responses by reducing ligand availability for, and receptor expression of, TNFR1 and TLR4 pathways. Also, GTE protects against metabolic endotoxemia by restoring intestinal tight junction protein expression. Lastly, studies in loss-of-function TLR4-mutant mice showed that GTE exerts it antiinflammatory activities at the liver in a TLR4-dependent manner, whereas intestinal-level benefits are mediated in a TLR4-independent manner. These findings are of significance in that they provide evidence to support GTE as a dietary strategy for NASH, specifically inflammation that mediates hepatic injury. These findings also provide basis for future clinical trials on the (open full item for complete abstract)

Committee: Richard Bruno (Advisor); Amanda Bird (Committee Member); Ouliana Ziouzenkova (Committee Member); Andrea Doseff (Committee Member) Subjects: Nutrition

PhD, University of Cincinnati, 2011, Medicine: Industrial Hygiene (Environmental Health)

Introduction: Exposures to airborne microbial contaminants in sub-micrometer particles (PM1) have not been well characterized in different environments. Health effects due to these exposures are even more obscure. Methods: Concentrations of airborne size specific (=1, 1-1.8, >1.8 µm) microbial contaminants (endotoxin, ß-glucan) were determined using cyclone samplers in two distinctly different environments: farms and homes. Using inhalable samplers and vacuum cleaners airborne inhalable and dust contaminants from these homes were collected. This approach was used to compare PM1 microbial contaminants in a particular home with those in inhalable particles and in dust inside the same home. Samples were analyzed with Limulus Amebocyte Lysate assays for endotoxin and ß-glucan. Walkthrough surveys and questionnaires determined home characteristics and other exposures. Airway inflammation was assessed in school-age children by measuring exhaled nitric oxide (eNO) levels with non-invasive nitric oxide monitoring system (NIOX-Flex). Skin-prick test were also employed to determine atopy. Results: Relative proportions of PM1 (=1 µm) microbial contaminants from total airborne concentrations were significantly higher in homes despite their significantly higher actual concentrations on farms. In homes, PM1 and inhalable endotoxin concentrations correlated weakly with that in dust and with each other. PM1 endotoxin levels were not significantly associated with eNO levels in asthmatics but had significant inverse association with eNO levels in non-asthmatics. Among non-asthmatics, eNO levels were significantly lower for those children who lived in homes with levels of dog allergens above detection limits and for those with lower parental income. Discussion: Moderate disturbance activities in homes preferentially allow PM1 microbial contaminants to predominate among total airborne particles compared to farming environments that have dynamic activity levels that cause re-suspe (open full item for complete abstract)

Committee: Tiina Reponen PhD (Committee Chair); Nancy Clark Burton PhD,MPH,CIH (Committee Member); Brett James Green PhD (Committee Member); Sergey Grinshpun PhD (Committee Member); Linda Levin PhD (Committee Member); Clara Ross MD (Committee Member) Subjects: Environmental Health

Master of Science, The Ohio State University, 2011, Animal Sciences

The development of systemic and local endotoxin tolerance (ET) in mid-lactation cows that experienced chronic subacute ruminal acidosis (SARA) or acute SARA and subsequent endotoxin mastitis was investigated. Twenty-four Holstein cows, both primiparous and multiparous, were assigned to eight blocks of three cows grouped by milk production, parity, and days in milk. Cows within blocks were randomly assigned to one of three treatments: 1) Control (Con), 2) High grain (Hi; formulated to reduce milk fat), and 3) Acidosis (designed to reduce milk fat for short periods and potentially induce clinical signs of rumen upset during these periods). Con and Hi treatment animals were fed their respective diets throughout the trial. The Acidosis cows were primarily fed the Con diet, but the Acidosis diet was fed for two two-day periods one week apart. Both Hi and Acidosis diet cows experienced SARA as measured by milk fatty acid profile alterations. Hi cows experienced reduced milk fat percentage, increased trans-10-octadecenoic acid, trans-10, cis-12 conjugated linoleic acid, and increased total trans fatty acids. Acidosis cows had increased trans-10-octadecenoic acid and increased total trans fatty acid content during acidosis bouts. On d 20, all cows were challenged via intramammary infusion with 10 µg of lipopolysaccharide (Escherichia coli 0111:B4) in one mammary quarter 3 h after morning milking. No systemic indicators of ET were observed among treatments. Evidence of an ET response at the local level of the mammary gland was observed. Hi diet animals had reduced milk amyloid A concentration at 12 and 24 h post-LPS in comparison with Con diet cows. Acidosis cows also had lower milk amyloid A concentrations than Con diet cows at 12 h. In addition, Hi diet cows had lower peak somatic cell count at 12 h when compared with Con diet cows. Our data suggest cows which experience varying degrees of SARA and subsequent experimental endotoxin mastitis experience endotoxin tolerance (open full item for complete abstract)

Committee: Joseph S. Hogan PhD (Advisor); William P. Weiss PhD (Committee Member); Kristy M. Daniels PhD (Committee Member) Subjects: Animal Diseases; Animal Sciences

Doctor of Philosophy, The Ohio State University, 2007, Animal Science

Failure to terminate the inflammatory response results in chronic inflammation that may lead to disease or cancer, especially in epithelial cells. We explored mammary epithelial cells as a model to identify mechanisms of anti-inflammatory activity in epithelia alone in the absence of immune cells. Bacterial endotoxin (ET) added to SCp2 mammary secretory epithelial cells: (1) induced both interleukin-6 (IL-6) secretion and nitric oxide (NO) production, but with unexpected delay in expression of mRNA for iNOS compared to IL-6; and (2) NFκB activation by 1 h after ET application (post-ET) that was transient for NFκB/p65 but persisted for NFκB/p50. Selective inhibition of NFκB activation by Wedelolactone reduced ET-induced expression of IL-6 mRNA and protein but not iNOS mRNA or NO production, suggesting differences in ET-induced IL-6 and iNOS regulation via NFκB activation. Serum supplementation but not soluble extracellular matrix (EHS) enhanced ET-induced IL-6 mRNA expression and protein secretion without affecting iNOS mRNA expression or NO production, confirming the different modes of regulation of IL-6 and iNOS expressions. Culturing SCp2 cells on a confluent monolayer of SCg6 mouse mammary myoepithelial cells increased IL-6 secretion dramatically even in the absence of ET, with ET treatment further increasing IL-6 secretion but having little effect on induction of NO production over that for SCp2 cells alone; showing importance of microenvironment and cell-cell interaction in regulation of inflammation and likely its link to cancer in epithelia. ET-induced inflammation in SCp2 cells was used to screen and identify anti-inflammatory fractions of methanol extracts of wild Lebanese Centaurea ainetensis, used in Lebanese folk medicine to treat inflammatory diseases. A partially purified solid phase (SPE columns) methanolic elution fraction of C. ainetensis followed by methanol gradient elution on reverse phase HPLC chromatography (RP-HPLC) strongly inhibited ET-induc (open full item for complete abstract)

Committee: Floyd Schanbacher (Advisor); Charles Brooks (Other); James DeWille (Other); Joy Pate (Other) Subjects:

Doctor of Philosophy, Case Western Reserve University, 2010, EECS - Electrical Engineering

Microfabricated silicon nanoporous membranes (SNM) are a breakthrough technology with potential in biomedical applications that include, but are not limited to, artificial organs, drug delivery, cell encapsulation, and water purification. SNM have a number of highly advantageous characteristics when compared to polymer filters commonly used in such applications, such as increased chemical and mechanical stability. The characteristic of greatest interest, however, is the monodisperse pore size distribution achieved by the sacrificial removal of a highly controlled silicon oxide layer grown by thermal oxidation. The monodisperse pore size distribution allows for a greater level of characterization of pore and membrane behavior than would otherwise be possible. As such, investigations into the transport and electrical properties of SNM as a whole can be interpreted as an aggregate of individual pores. This work explores the electrical properties of the solution-pore interface via the streaming potential. This is followed by investigations of the size-based and charge-based filtration characteristics of the SNM using fluorescently labeled neutral and anionic Ficoll, a polysaccharide with low asymmetry. Finally, SNM are employed in the removal of endotoxin from an aqueous solution, a critical process in the production of medical grade water.

Committee: Christian Zorman PhD (Committee Chair); Aaron Fleischman PhD (Committee Co-Chair); Francis Merat PhD (Committee Member); Miklos Gratzl PhD (Committee Member) Subjects: Electrical Engineering

Master of Science, University of Akron, 2006, Biology

The purpose of this project was to investigate how zirconium alloys resist microbial biofilm formation and endotoxin adhesion in a simulated biological system. With the intent of potentially developing this class of alloys for orthopedic implant applications, it was necessary to determine their stability in a biological environment. Because zirconium alloys have been shown to demonstrate chemical stability in industrial applications, it follows that their corrosion resistant properties have the potential to transfer to biological systems. The analytical scope of this project assessed the ability of un-oxidized Zirconium-705 (Zr-705), thermally processed Zr-705, and thermally processed Zircaloy-2 (Zry-2) to resist biofilm formation and endotoxin adhesion by clinical strains of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Candida albicans, and all four in combination. Microbial analysis specifically involved viable counts and the limulus amebocyte lysate gel clot assay. Statistical analyses revealed that the thermally processed 4µm Zr-705, when compared to un-oxidized Zr-705, 2µm Zr-705, and 4µm Zry-2, demonstrated an overall greater resistance to microbial biofilm formation. The 4µm Zry-2, albeit statistically not significant, was optimal in deterring bacterial endotoxin adhesion. Further, a shaken incubation condition, on average, was significantly more effective than a stationary incubation condition in resisting microbial and endotoxin adhesion. This project demonstrated the potential usefulness of zirconium alloys for orthopedic implants.

Committee: Dr. Martha Kory (Advisor); Dr. Monte Turner (Other); Dr. Rex Ramsier (Other); Dr. Richard Londraville (Other) Subjects: Biology, Microbiology