Heart Failure is the state in which the heart is unable to pump enough blood to meet the needs of the body, resulting from events that progressively damage the myocardium and/or its ability to contract normally. Several compensatory mechanisms allow for short-term maintenance of adequate delivery of blood to the body. Progression from the initial events to heart failure is caused by the accumulation of pathologic changes and their effects, many of which result from chronic activation of these compensatory mechanisms. One of these mechanisms is the activation of the neurohormonal β-adrenergic system, to which the β₃-adrenergic receptor (β₃-AR) belongs. Research on the role of the β₃-AR in the heart has focused on the short-term protective role of the receptor, based on its ability to reduce the effects of over-stimulation of the heart's other adrenergic-system components. However, during the course of heart failure, its up-regulation and functional persistence may also contribute to the progression of the disease. There have been few large-animal studies, no human trials, and no long-term studies of β₃-AR agonists for use in the treatment of heart failure. Ultimately, individualized treatment strategies that, over time, modulate the relative levels of agonistic and antagonistic effects across each of the three β₃-AR subtypes, may be most effective for management of heart failure. However, further research and trials with β₃-AR agonists are realistic and necessary places to start.

The epidemiology of head and neck squamous cell carcinomas (HNSCC), primarily those of the oropharynx, has changed dramatically over the last two decades. Specifically, HNSCC appears to be a distinct entity that is related to infection by human papilloma virus (HPV)(Vokes et al., 2015) (Fakhry et al., 2008). Moreover, the incidence of HPV-associated oropharyngeal (OP) cancers is rising, likely as a consequence of changing life styles and sexual behaviors. These tumors appear to be biologically and clinically distinct from other HNSCC tumors affecting predominantly middle-aged white men having no or only a brief history of tobacco consumption. The cell cycle regulatory protein, p16, is usually over expressed in HPV-OPSCC, and its detection using immunohistochemistry and in situ hybridization is a reliable surrogate marker for the disease (Ang et al., 2012). When compared to traditional head and neck cancer that is associated with the repeated insult of tobacco use, HPV-related OPSCC has a favorable natural history and is more responsive to treatment. As a result, patients with this cancer have improved long-term survival and consequently are more likely to experience chronic therapy-induced morbidity (Ang et al., 2012). The purpose of this thesis is to provide a comprehensive review of the molecular mechanisms that underlie HPV-mediated OPSCC, and the licensed prophylactic HPV vaccinations available, and to discuss the current thoughts on whether to deescalate potentially damaging treatments in these patients.

Duchenne muscular dystrophy is an inherited, X-linked recessive skeletal muscle disorder that is characterized by mutations in the dystrophin gene [1]. Therefore, the disease affects primarily males and women are typically carriers. 1 in 3500 males in the United States are affected [1]. Dystrophin is a critical, large scaffolding protein in the dystrophin-glycoprotein complex found at the sarcolemma of skeletal muscle [1]. The complex helps maintain sarcolemma integrity and stability during muscle contractions by coupling the extracellular matrix proteins to the intracellular cytoskeleton in skeletal muscle [1]. Loss-of-function mutations in the dystrophin protein affect all skeletal muscle found throughout the human body. The 427 kD protein is also present in cardiac muscle, the brain, and peripheral nerves, thus affecting these tissues over time, as well [1]. One theory suggests the weakened stability of the dystrophin-glycoprotein complex when dystrophin is not expressed results in transient membrane tears during contraction, which permit pathological calcium influx [1]. Damaged skeletal muscle results in repair and regeneration of the tissue however, continual damage over time (referred to as muscle wasting) results in extensive fibrosis and loss of muscle fibers. The purpose of this thesis is to provide a comprehensive review on several molecular mechanisms that underlie Duchenne muscular dystrophy and to investigate current treatments and propose potential therapeutic targets for future research.

Chromosomal Instability (CIN) occurs in over 90% of all sporadic tumors and manifests as whole chromosome loss or gain, gene deletions, amplifications, inversion, and translocations. CIN is not only a hallmark of cancer but promotes tumorigenesis. CIN is caused by errors during mitosis and one major CIN-promoting mechanism is centrosome over-duplication (amplification); another cancer hallmark. Centrosome amplification causes abnormal mitotic spindle assembly, directly promoting chromosome mis-segration with consequent aneuploidy and other forms of CIN. Central to controlling centrosome numbers and function are the Polo kinases, including Polo-like kinase 4 (Plk4). Plk4 is a component of centrosomes and recognized as the master-regulator of centrosome function and duplication. Plk4 is a mitotic kinase whose levels increase throughout S-phase and G2 to peak in mitosis. During late mitosis, Plk4 localizes to a spot on parent centrioles, licensing this single site for future daughter centriole assembly. Plk4 activity initiates the hierarchial recruiment of two conserved essential centriole proteins: Ana2, followed by the cartwheel protein Sas6. By analysis in a yeast-2-hybrid screen, we identified several novel interactions of centriole proteins, including the interaction of Ana2 and Plk4. Plk4 phosphorylates Ana2 to both positively and negatively regulate centriole duplication. Our preliminary data suggests that Plk4 recruits Ana2 by phosphorylating a protein on the outer centriole surface, generating a phospho-landing platform, and that this Plk4 target is Sas4 (CPAP in humans). Notably, the Sas4 pattern on centrioles is complex, forming both a ring and an asymmetric spot during mitotic progression. Like Sas4, Ana2 is a Plk4 substrate, and when mixed with purified Ana2, Sas4 stimulates Ana2 hyperphosphorylation in vitro. Thus, Plk4 influences centriole assembly on multiple platforms.

High-risk human papillomaviruses (HPVs) cause 5% of all human cancers worldwide. The HPV capsid consists of 72 disulfide-linked pentamers of major capsid protein L1 and up to 72 molecules of minor capsid protein L2. The viral genome (vDNA) is 8KB circular dsDNA, condensed with histones and complexed with L2. HPV infection requires the virion particle to get access to basal layer keratinocytes, binding and entry of the cells, uncoating, and transport of the viral genomes to the host cell nucleus. During infection, L2 is important for transport of the viral genome from membrane bound vesicular compartments, through the cytosol and into the host cell nucleus. Previous work has identified a conserved disulfide bond between Cys22 and Cys28, which is necessary for HPV16 infection. We hypothesize that endosomal reduction of this disulfide might be important for L2 conformational changes that allow a hydrophobic transmembrane-like region in L2 to span across endosomal membranes, exposing sorting adaptor binding motifs within L2 to the cytosol. Prior research suggests that cytosolic glutathione (GSH) redox potential is important for reduction of disulfide-linked proteins within the lumen of endosomes. This is achieved by endosomal influx of cytosolic reduced cysteine, where it can reduce disulfide bonds in lumenal proteins. Cytosolic GSH regenerates the pool of reduced cysteine needed to maintain endosomal redox potential. Here we studied the relationship between cytosolic GSH and HPV16 infection. siRNA knockdown of critical enzymes of the GSH biosynthesis pathway or the endosomal cystine efflux pump cystinosin caused partial abrogation of HPV16 infection. Likewise, inhibition of the GSH biosynthesis pathway with L-buthionine sulfoximine (L-BSO) blocked HPV16 infection in multiple cell types, suggesting that cytosolic GSH redox may be important for HPV16 infection. Further studies have revealed that the decrease of HPV16 infection is not because of defects in binding, entry, L2 cleavage or capsid uncoating, but rather is due to inefficient cytosolic translocation of L2/viral genome from the trans-Golgi network (TGN). Contrary to our initial hypothesis, we show that L2 is able to span the endosomal membrane and direct TGN localization in the presence of BSO. Lack of cytosolic GSH causes L2/viral genome to become trapped in the TGN lumen. This suggests that there are redox-sensitive viral or cellular factors necessary for L2/viral genome translocation at the TGN. Future research will focus on the redox state of the Cys22-Cys28 disulfide bond during infection of normal and GSH-depleted cells.

Vascular endothelial growth factor-B (VEGF-B), when initially discovered, was thought to be an angiogenic factor, due to its intimate sequence homology and receptor binding similarity to the prototype angiogenic factor, VEGF-A. Studies demonstrated VEGF-B, unlike VEGF-A, did not play a significant role in angiogenesis or vascular permeability and has become an active area of interest because of its role as a survival factor in pathological processes in a multitude of systems, including the brain. By characterization of important downstream targets of VEGF-B that regulate different cellular processes in the nervous system and cardiovascular system, it may be possible to develop more effective clinical interventions in diseases such as Parkinson's disease (PD), Amyotrophic Lateral Sclerosis (ALS) and ischemic heart disease, which all share mitochondrial dysfunction as part of the disease. Here we summarize what is currently known about VEGF-B function in pathological processes, compare probable mechanisms of action and elude to its potential as a homeostatic protective factor to increase mitochondrial function in the setting of neurological disease and cardiovascular disease.

Human papillomaviruses (HPV) are among the most common sexually transmitted infections and are responsible for 5% of all human cancers. HPV type 16 is the most prevalent of the high-risk HPVs (a subgroup of HPVs with potential to cause cancer), accounting for ~55% of HPV-associated cancers. HPV16 is a nonenveloped virus, composed of the major capsid protein L1, the minor capsid protein L2, and a circular double-stranded DNA genome (vDNA) condensed with human histones. HPV initially infects undifferentiated basal keratinocytes and viral replication is dependent on epithelial differentiation. Like many other DNA viruses, HPV must deliver its vDNA to the host cell nucleus to successfully replicate. Initial binding of HPV16 to host cells is through L1 interactions with cell surface heparan sulfate receptors. Shortly after virus binding, L2 is believed to undergo furin cleavage-dependent conformational changes, resulting in spanning of the protein across the local membrane and exposure of the central and C-terminal regions of L2 (which was lumenal and and inaccessible before furin cleavage) to the host cell cytosol. L2 is critical for transport of the L2/vDNA from endosomes to the trans-Golgi network (TGN). We hypothesize that furin-dependent early L2 spanning, through the direct binding and recruitment of cytosolic sorting factors, may contribute to viral endocytosis and subcellular retrograde trafficking (trafficking from endosomes to Golgi) of vDNA. We have developed a Tac receptor (CD25 or IL2 receptor, a transmembrane cell surface protein) chimera system to study L2-dependent endocytosis and trafficking. In this system the Tac ecto- and transmembrane domains are fused to the ~400 amino acid portion of L2 that is likely cytosolic upon L2 spanning. Through transient expression of Tac-L2 chimera we use anti-Tac ectodomain antibodies to label and track cell surface populations by immunofluorescence and confocal microscopy. We have also adopted this system to study endocytosis through a cell surface biotinylation approach. Both approaches suggest that L2 may enhance endocytosis and preliminary evidence suggests that the Tac-L2 chimera may recruit the cytosolic retromer complex (the host cytosolic factors help protein retrograde trafficking) to preferentially traffic to the TGN. Retromer-dependent trafficking of cargo from early endosomes to the TGN is known to involve certain members of the sorting nexin family, specifically the SNX-BAR proteins. We performed a small siRNA screen and identify SNX6 and SNX32 (aka SNX6b) as SNX-BAR proteins that may be specifically involved in retrograde trafficking of HPV16 L2/vDNA during infection. Future work will focus on the mechanisms through which L2 and SNX6 influence HPV16 entry and trafficking.

Nicotine from smoking or from other products containing nicotine has adverse effects on the fetus during pregnancy, such as respiratory problems. Our laboratory has previously shown that exposure to nicotine during development (DNE) alters hypoglossal motor neuron (XII MN) function, including decreased excitatory synaptic input, desensitized nicotinic acetylcholine receptors, increased input resistance, and differences in the precision and reliability of spike timing in XIIMNs. Evidence of DNE effects on XIIMN function prompted us to test the hypothesis that DNE will affect the development of primary dendrites and the soma. Brainstem slices were collected from neonates and motoneurons were filled with neurobiotin via whole-cell patch clamp. Filled cells were visualized with heavy metal intensified-3,3'-Diaminobenzidine (DAB) reaction. DAB-stained cells were analyzed using Neurolucida hardware and software. On average, the maximum soma diameter of more rostral XIIMNs was larger than that in more caudal cells. Also, caudal XIIMNs had more primary nodes than rostral XIIMNs, and there was a significant treatment effect on minimum soma diameter (Control, 13.76 ± 0.71 µm; DNE, 18.09 ± 1.22 µm). The results from this study uncovered potential effects of nicotine on XIIMNs found in rostral and caudal regions of the hypoglossal nucleus.

Malaria is a leading cause of death in some developing countries. The malaria parasite has been around for over a century, and has coevolved with humans. Coming up with an effective vaccine for P. falciparum will save millions of lives and reduce the morbidity and mortality of malaria globally. Understanding the role of exported parasite proteins i.e PfEMP1 a virulence factor and major cause of malarial pathogenesis, has been of great interest to vaccine researchers in the last decade. The focus of this review is to provide a literature review on PfEMP1s, their interaction with the human immune system, and their role in helping P. falciparum parasite to evade the immune system. This review will primarily focus on the intra-erythrocytic stage, which is the stage that results in the symptoms of malaria. A review is necessary to understand the antigenic variation of PfEMP1s, and how PfEMP1s challenge the different arms of the immune response, both the innate and adaptive. This review is unique in touching on the major parts of the immune system's interaction with the PfEMP1 antigen. Furthermore, the review explores the discussion of future research and therapeutic opportunities based on our knowledge of PfEMP1 antigens.

Myasthenia gravis (MG) is an autoimmune disease whose name means "grave muscular weakness". MG is a rare disease affecting only 200-400 persons per million and the characteristic symptoms include muscle weakness, particularly in highly active voluntary muscles. MG affects the neuromuscular junction in an antibody-mediated manner, resulting in impaired nerve-muscle cell communication in affected individuals. Specifically, two main proteins are targeted: nicotinic acetylcholine receptors (ACh receptors) and a muscle-specific tyrosine kinase (MuSK). Previous studies have discovered the mechanism of MG pathogenesis but the exact mechanisms which cause the failure to maintain self-tolerance have not been discovered. Based on current knowledge of MG, this paper will explore potential causes of the disease and provide numerous hypotheses directed at future research opportunities.