Doctor of Philosophy (PhD), Ohio University, 2020, Translational Biomedical Sciences

Emerging evidence has demonstrated that the gut microbiome plays an important role in both host physiology and pathophysiology of disease. That is, gut microbes and their metabolites influence host metabolism, endocrinology, immunology, neurology, and growth. For instance, gut microbes have been shown to impact linear growth partially by altering the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis. Conversely, several metabolic and intestinal diseases (including chronic undernutrition, inflammatory bowel disease, non-alcoholic fatty liver disease, obesity, and diabetes) not only share a lack of microbial diversity in the gut but have abnormalities in GH action. To date, however, limited research has focused on the potential impact of GH on the gut microbiome. The studies detailed in this dissertation thus aimed to investigate the potential role of GH on the gut microbial profile. The first study optimized the methodology to quantify the mouse gut microbiome from fecal collection to data analysis. The second study set out to characterize the microbial abundance, maturity, and predictive metabolic function in two mouse lines of opposing GH action: 1) a GH deficient (GH-/-) mouse line and 2) a GH excess mouse line (bGH). We observed several distinct microbial and intestinal findings in both mouse lines compared to controls. Collectively, the results presented suggest that GH indeed alters the gut microbiome. Moreover, opposing microbial trends between the two mouse lines suggest that GH is associated with the presence of certain microbes, increases maturation of the microbial community, and alters predictive metabolic pathways involved in acetate, butyrate, folate, and heme B biosynthesis. The third study delved deeper into the relationship between excess GH action and the longitudinal gut microbiome. That is, this study tracked the longitudinal changes in microbial abundance, maturity, and predictive metabolic function and intestinal phenotype in (open full item for complete abstract)

Committee: Darlene Berryman PhD, RD, LD (Advisor); Erin Murphy PhD (Advisor); Ronan Carroll PhD (Committee Chair); Edward List PhD (Committee Member); Cheryl Howe PhD (Committee Member); Helen Raybould PhD (Committee Member) Subjects: Biomedical Research; Endocrinology; Histology; Microbiology; Molecular Biology

Bachelor of Science (BS), Ohio University, 2020, Biological Sciences

Adipose tissue (AT) is a unique energy storage tissue able to undergo significant hypertrophy and atrophy, dependent, in part, on nutrient status. When hypertrophy is in excess and sustained, the result is obesity, a common and widespread health problem. However, when AT stores are selectively depleted or abnormally deposited, the resultant condition known as lipodystrophy can lead to comparable health outcomes as obesity. That is, either extreme in AT mass results in similar metabolic outcomes (insulin resistance, increased immune cell infiltration, and increased production of inflammatory cytokines). With either chronic obesity or lipodystrophy, AT can undergo major remodeling, which can ultimately result in unresolved chronic inflammation and AT fibrosis. Growth hormone radically alters AT mass, and mice that overexpress growth hormone (bGH mice) are lipodystrophic with a notable increase in AT fibrosis. Key players in AT fibrosis could include fibroblast activation protein (FAP) and fibroblast growth factor 21 (FGF21), among others. FAP has been positively correlated with ECM remodeling and its knockdown has been associated with improved metabolism in diet induced obese mice, while FGF21 is associated with increased energy expenditure yet is cleaved and inactivated by FAP. Importantly, FGF21 and FAP levels were also recently assessed in patients with acromegaly, and these molecules were suggested as a marker of tissue fibrosis and positively correlate with GH action. [1] These results provide compelling evidence that assessing the FAP/FGF21 interaction in our bGH mice will help elucidate the mechanisms underlying the relationship between GH and fibrosis. Thus, the purpose of this study was to determine if these molecules are altered in bGH mice. Using serum and plasma collected from bGH and littermate controls and ELISA assays, our results indicate that FAP is not significantly altered in adult bGH mice, although sex s (open full item for complete abstract)

Committee: Darlene Berryman PhD, RD, LD (Advisor) Subjects: Biology; Biomedical Research

Doctor of Philosophy (PhD), Ohio University, 2019, Molecular and Cellular Biology (Arts and Sciences)

Type 1 diabetes (T1D) is on the rise globally, and both genetic and environmental factors are thought to play a role in triggering this disease. Female non-obese diabetic (NOD) mice are useful for studying T1D as they spontaneously develop T1D even when raised in a sterile environment. However, viruses, such as Coxsackievirus B4 (CVB4), will accelerate the onset of T1D in NOD mice when the infection occurs after a `threshold of insulitis' has been reached, usually between eight to ten weeks of age. Viral-induced T1D and beta cell destruction is believed to be driven in part by viral triggering of toll-like receptor 3 (TLR3), an innate immune receptor that recognizes viral dsRNA and whose signaling results in the production of key cytokines, chemokines and other antigen presenting molecules that are known to play a role in the pathogenesis of T1D. It has been previously shown that TLR3 plays a critical role in viral acceleration of T1D in female NOD mice since female TLR3 knockout NOD mice are protected from CVB4-induced acceleration of T1D. However, the exact role(s) that TLR3 plays in the pathogenesis of CVB4-induced T1D is not yet known. We utilized a molecular and cellular biology and time-course approach in uninfected and CVB4-infected female wild-type and TLR3 knockout NOD mice to garner a better understanding of the mechanisms by which TLR3 is involved in viral-mediated T1D. Our studies reveal that in uninfected NOD mice, TLR3 is involved in establishment of the `critical threshold of insulitis' by 1) increasing CD3+ T cell infiltration within the pancreas and 2) increasing downstream signaling of CXLC10 needed to recruit immune cells to the pancreatic islets. Additionally, TLR3 is involved in 1) limiting the proportions of T regulatory cells within the spleen, 2) mediating an increase in cytotoxic T cell infiltration and number of macrophages and dendritic cells within the pancreas, as well as 3) upregulating pancreatic chemokines and cytokines that enhance (open full item for complete abstract)

Committee: Kelly McCall (Advisor) Subjects: Endocrinology; Molecular Biology

Master of Science (MS), Ohio University, 2014, Biological Sciences (Arts and Sciences)

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease and renal failure in humans. The molecular pathways that lead to DN are not well known. This research investigates possible roles of several signal transducers and activators of transcription (STAT) proteins in this disease using a STAT5A/B knockout (SKO) mouse model. Based on previous observations of increased inflammation-related gene expression in the kidneys of diabetic SKO mice, the hypothesis of the current project was that the combination of the loss of STAT5 repression and increase of STAT3 activity escalates inflammation-related gene expression in the kidneys of diabetic SKO mice. In support of this hypothesis, an increase of IRF-1 RNA expression, reflective of the loss of STAT5 repression, was observed in the kidneys of diabetic SKO mice. Levels of phosphorylated STAT3 were also increased in the kidneys of diabetic SKO mice. These results suggest that STAT5 acts as a repressor of inflammation-related genes in DN and, in its absence, expression of these genes is no longer repressed, either due to direct loss of the STAT5 repression or due to increased STAT3 activity which could potentially increase their expression.

Committee: Karen Coschigano PhD (Advisor); Calvin James PhD (Committee Member); Ramiro Malgor MD (Committee Member) Subjects: Animals; Biology; Biomedical Research; Immunology; Molecular Biology

MA, University of Cincinnati, 2005, Allied Health Sciences : Audiology

C57BL/6J (B6) mice are the experimental model for presbycusis, and have been shown to be more susceptible to noise-induced hearing loss. The congenic B6-Cast mouse is genetically identical to the B6 strain, except that the Ahl gene has been replaced with a wild-type, gene for normal hearing. As a result, B6-Cast mice are thought to be resistant to the effects of aging and noise. The purpose of this study is to assess the effects of noise-exposure at specific ages on the expression of the Ahl gene. Results indicate that both strains of mice actually exhibit presbycusis and noise-induced hearing loss, but the B6-Cast strain develop hearing loss at a slower pace compared to the B6 strain. These results suggest that there is at least one other gene, other than Ahl, in the background of the B6 mice that contributes to the hearing losses experienced in this study.

Committee: Susan Stanton (Advisor) Subjects:

Master of Science (MS), Ohio University, 2008, Nutrition Science (Health and Human Services)

Microarray analyses were performed comparing mRNA expression levels in subcutaneous adipose tissue between mice with disruption in the growth hormone (GH) receptor gene (GHR-/- mice) and littermate controls. The data revealed that 87 genes were significantly upregulated and 72 genes were significantly downregulated in GHR-/- mice versus littermate controls. Among the 159 altered genes, a subgroup of five genes was chosen for confirmation by a second mRNA quantification method, real time reverse transcriptase polymerase chain reaction (RT-RT PCR). RT-RT PCR studies confirmed the altered gene expression for only three genes, angiotensinogen (Agt), adiponutrin (Adpn) and angiopoietin-like protein 4 (Angptl4). To better understand the role of GH in adipose specific expression of these three genes (Adpn, Agt, Angptl4), RT-RT PCR analysis was expanded to include an additional genotype of altered GH function, the bovine GH transgenic mice, an additional diet treatment high-fat diet, as well as two other adipose depots, the epididymal and retroperitoneal adipose depots. This thesis discusses in detail all gene alterations observed in the microarray analyses and the RT-RT PCR analyses for Adpn, Agt, Angptl4 in adipose tissue.

Committee: Darlene E. Berryman PhD (Advisor); Karen Coschigano PhD (Committee Member); Diana Manchester MS (Committee Member) Subjects: Biology; Biomedical Research; Cellular Biology; Molecular Biology; Nutrition

Doctor of Philosophy, Case Western Reserve University, 2006, Pharmacology

The 15-30% of human breast cancers that have upregulated HER2/ErbB2/Neu are highly aggressive and resistant to traditional treatments, resulting in poor prognosis. To identify novel therapeutic targets, we derived the transcriptomes associated with tumor progression in two independent mouse models of ErbB2/Neu-induced tumorigenesis. From MMTV-Neu mice, we identified 324 candidate genes unique to ErbB2/Neu-induced tumors relative to wild-type mammary glands. A subset of these genes also changed expression levels in preneoplastic mammary glands, indicating a pivotal role early in ErbB2/Neu-initiated tumorigenesis. Downregulation of several known transforming growth factor (TGF)-β target genes in the ErbB2/Neu molecular signature suggested attenuation of the TGF-β signaling cascade in these tumors. Analysis of TGF-β-Receptor-I/ALK5 by western blot and immunohistochemistry confirmed that Smad-dependent TGF-β signaling was inactive in these tumors. Although absent in most of the tumor, colocalization of phosphorylated Smad2 and Activin-Receptor-IB/ALK4 at the tumor periphery suggested functional Activin signaling at the leading edge of these tumors. Collectively, these data indicate intrinsic TGF-β pathway suppression in ErbB2/Neu tumors via loss of TGF-β-Receptor-I/ALK5. Recent studies have shown that pregnancy can accelerate ErbB2/Neu tumor development, inducing a susceptible cell population in MMTV-Neu mammary glands. The stochastic pattern of tumor development in multiparous MMTV-Neu mice suggests additional events are required for ErbB2/Neu oncogenesis. It remains unclear whether such events are genetic or reflective of the dynamic, pregnancy-associated hormonal control of the gland. Bitransgenic mice generated by breeding MMTV-Neu mice with a model of ovarian hyperstimulation developed multifocal mammary tumors in an accelerated, synchronous manner compared to virgin MMTV-Neu animals. This synchrony of tumor development suggests that trophic maintenance of the mamm (open full item for complete abstract)

Committee: Ruth Keri (Advisor) Subjects:

Master of Science (MS), Ohio University, 2013, Food and Nutrition Sciences (Health Sciences and Professions)

Growth Hormone (GH) is known as a diabetogenic molecule. In excess it can inhibit insulin's action resulting in insulin resistance and diabetes, which can be seen in the GH receptor knockout (GHR-/-) mice since the absence of GH action throughout the whole body improves insulin sensitivity and increases life span. Three tissues that are both insulin and GH sensitive are liver, adipose tissue, and muscle. To determine their individual contributions, three tissue specific GHR disrupted mouse lines have been independently produced: liver-specific, adipose-specific, and muscle-specific GHR-/- mice using the CRE-LOX system. Tissue specific promoters, albumin, aP2, MCK, were utilized to drive the CRE recombinase expression in liver, adipose, and muscle tissues separately. This thesis aimed to validate the gene deletion in specific tissues at the DNA level. The results confirm that liver and muscle specific GHR-/- mice had the deletion of the GHR gene in the liver and muscle tissues, respectively. However, in the adipose specific GHR-/- mice, all tissues, and not just adipose tissue, had evidence of GHR deletion. These findings need to be taken into account when evaluating the phenotype.

Committee: Darlene Berryman (Advisor); Edward List (Committee Member); Deborah Murray (Committee Member) Subjects: Aging; Molecular Biology

Master of Science, The Ohio State University, 1961, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 2007, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1969, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 2008, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1958, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1965, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1923, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1971, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1964, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1950, Graduate School

Committee: Not Provided (Other) Subjects:

Bachelor of Arts, Wittenberg University, 2024, Biology

Obsessive Compulsive Disorder, or OCD, is a disorder characterized by intrusive thoughts and repetitive actions (Couto et al., 2018), and affects about 2-3% of the U.S. population (“What is obsessive-compulsive disorder”, 2024). Although there are no molecular concrete causes of OCD, it is thought that abnormalities in the glutamate and serotonin pathways may have large impacts on the symptoms that cause OCD. Furthermore, there are many genes that may have a linkage to OCD and its comorbidities. Currently, as a main treatment SSRIs may be combined with anti-psychotic drugs such as Risperdal, but they are only effective about 40%- 60% of the time (Allen et al., 2018). Cognitive Behavioral Therapy can also be used in combination as a treatment for OCD. There have been studies in both mice and humans that suggest N-Acetylcysteine, or NAC, may be useful in reducing OCD symptoms (CITATION). Mice were exposed to NAC for 1 or 3 weeks, and then injected with a saline or RU42969 (5HT1A/1B agonist) to induce OCD-like symptoms. They were then observed behaviorally, and their cDNA was harvested. The involvement of different genes in NAC and OCD pathways is not completely known. Therefore, qPCR was used to test the expression of seven different genes—DRD2, GRIK2, SLC1A2, HTR2A, MAOA, PRL, and OXTR—and their connection to OCD and NAC. Two of the seven genes (28.6%) that were studied were significantly affected by 1 Week NAC + OCD. Two of the seven genes (28.6%) were significantly affected by 3 Week NAC + OCD. Three of the seven genes (42.9%) were significantly affected by 3 Week H20 + OCD. Overall, the results suggest that many of the genes we looked at are not necessarily involved in the NAC pathways but perhaps are involved in the OCD pathway. More research is needed to determine the genes that are significantly affected by NAC on its own, and further research can be done to strengthen the literature on interactions between these genes and OCD.

Committee: Michelle McWhorter (Advisor); Gwynne Davis (Committee Member); Margaret Goodman (Committee Member) Subjects: Biology; Mental Health; Neurobiology; Neurology; Neurosciences; Psychobiology; Psychology

Master of Science, Miami University, 2024, Biology

Lyme disease, caused by the bacterium Borrelia burgdorferi , is transmitted to humans through ticks, and it has become an increasing problem in the Midwest. In recent years, cases have been expanding from a hotspot in Wisconsin to Michigan's Lower Peninsula (LP) along the coastline of Lake Michigan. The expansion of cases coincides with increasing populations of deer tick, Ixodes scapularis , and of the white-footed mouse, Peromyscus leucopus , which serves as the primary reservoir host for the bacterium. A study from 2010 testing the infection prevalence in both deer ticks and white-footed mice found no infections in either species in most of the northern LP. For this study, mice were trapped along a transect from the edge of the known range of infected mice northeastwards toward the tip of the LP. Infected mice and ticks were found more than 100km beyond the previous limit but were not found along the eastern part of the transect. The proportion of P. leucopus carrying ticks was correlated with higher infection prevalence in both ticks and mice.

Committee: Susan Hoffman (Advisor); Brian Keane (Committee Member); Tereza Jezkova (Committee Member) Subjects: Biology