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Browsing by Author "Moreno, Julie A., committee member"

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    A multimethod simulation paradigm for investigating complex cellular responses in biological systems of aging and disease
    (Colorado State University. Libraries, 2019) Hoffman, Timothy Edward, author; Hanneman, William H., advisor; Legare, Marie E., advisor; Wallis, Lyle E., committee member; Moreno, Julie A., committee member
    Classical studies in toxicology and disease research have relied on the use of high-dose experiments and often lacked quantitative and comprehensive components essential to understanding biological queries. These shortcomings in the research community have been the result of modern methodological limitations, however, more robust and expansive experimental and computational methods are emerging. In this dissertation, I present a novel multimethod computational simulation paradigm that adds value to new and existing studies of toxicological and pathological endeavors. First, I established the use of this approach for pharmacokinetic and pharmacodynamic applications, with published examples in regulatory exposure toxicology and contemporary dose-response nuances. Following establishing the success of this approach in toxicology, I then applied this methodology to the broader question of degenerative aging, as it has been arduous with conventional techniques to understand the various mechanisms that contribute to and protect against cellular aging. The foundational simulation created for general cellular aging was then expanded in the context of tauopathies and Alzheimer's disease to better quantify and understand the pathways involved in this age-dependent disorder. The final results presented here improve experimental translatability, robustness and descriptiveness in order to better understand age-related diseases. More broadly, this dissertation in totality attempts to minimize quantitative deficits in toxicological and pharmacological research.
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    Novel therapeutics, associated adverse effects, and changes in immune responses during pulmonary infection with Mycobacterium tuberculosis
    (Colorado State University. Libraries, 2024) Ali, Malik Zohaib, author; Gonzalez-Juarrero, Mercedes, advisor; Basaraba, Randall J., committee member; Moreno, Julie A., committee member; Chen, Chaoping, committee member
    Patients diagnosed with multidrug resistant (MDR) or extensively drug resistant (XDR) tuberculosis (TB) have limited treatment options. The Nix-TB clinical trial evaluated a new 6-month regimen containing three-oral-drugs; bedaquiline (B), pretomanid (Pa) and linezolid (L) collectively termed as BPaL for the treatment of TB. This regimen achieved remarkable results as almost 90% of the participants suffering from MDR- or XDR-TB had favorable outcomes. Despite the extraordinary outcomes, many patients also developed severe adverse effects (AEs) which were associated with the long-term administration of the oxazolidinone protein synthesis inhibitor linezolid. Spectinamide 1599 (S) is also a potent protein synthesis inhibitor of Mycobacterium tuberculosis (Mtb) with an excellent safety profile, but which lacks oral bioavailability. In chapter 2, we hypothesized that inhaled spectinamide 1599, combined with BPa ––BPaS regimen ––, has similar efficacy to that of BPaL regimen while simultaneously avoiding the L-associated AEs. The BPaL and BPaS regimens were compared in the BALB/c (permissive resistant) and C3HeB/FeJ (permissive susceptible) murine chronic TB efficacy models. Both regimens promoted similar bactericidal effects in lung and spleen of both models after 4 weeks. However, treatment with BPaL resulted in significant weight loss and the complete blood count suggested development of anemia. These effects were not similarly observed in mice treated with BPaS. BPaL treatment also decreased myeloid to erythroid ratio and increased concentration of proinflammatory cytokines in bone marrow compared to mice receiving BPaS regimen. During therapy both regimens improved the lung lesion burden, reduced neutrophil and cytotoxic T cell counts while increased the number of B and helper and regulatory T cells. This combined data suggests that inhaled spectinamide 1599 combined with BPa is an effective TB therapy that avoids L-associated AEs. The granuloma formation is the pathological hallmark of TB, and several studies suggest that there are temporal and spatial changes in their distinct immune responses. These changes differ not only from one granuloma to another in a single individual but also depend on the severity of the disease. In chapter 3, we attempted to understand longitudinal changes in immune cells, their relationships, and their spatial distribution in granulomas of Mtb infected BALB/c and C3HeB/FeJ mouse models using a novel technique of multispectral imaging microscopy. Multiplex fluorescence immunohistochemistry (mfIHC) is unique in its ability to provide both expression and location of several immune cells along with their co-localization in a single tissue section while preserving tissue architecture and spatial context. The results showed that as the infection progresses, there are also dynamic changes in the immune phenotypes forming the granulomas and those located within the parenchymal tissue. Moreover, the histologically similar granulomas manifested complexity in their immune cell composition mainly due to the presence of adaptive immune responses. The advanced cellular granulomas in BALB/c TB model were mainly predominated by CD4 and CD8 T cells, Ly6G stained neutrophils, B220 B cells and all these were surrounded by F4/80 macrophages. With time post infection, there was an increased uniform recruitment of CD4 and Foxp3 T cells, F4/80 macrophages and Ly6G neutrophils within granulomas compared to parenchymal tissue where IFNγ and IL-10 secreting cells were in abundance. Moreover, B220 B cells and CD8 T cells also showed increased but heterogeneous distribution among the advancing granulomas especially B220 B cells formed clusters. The spatial analysis showed an increased median distance for Ly6G neutrophils, whereas this distance was decreased for B220 B cells when measured from CD4 and CD8 cells. In summary, combining the spatial and temporal data in addition to the mere cell counts helps to uncover interactions and relationships between different immune cells within the granuloma.
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    Targeting proteostatic maintenance and mitochondrial function with phytochemical compounds in models of brain and skeletal muscle aging
    (Colorado State University. Libraries, 2024) Walsh, Maureen Ann, author; Hamilton, Karyn L., advisor; Fling, Brett W., committee member; Moreno, Julie A., committee member; LaRocca, Thomas J., committee member; Santangelo, Kelly S., committee member
    There is a growing population of older adults (>65+ years) worldwide that is projected to increase in coming decades, presenting both a challenge and an opportunity. Specifically, age is the number one risk factor for chronic diseases like sarcopenia, the loss of muscle mass and function, and neurodegenerative diseases such as Alzheimer's Disease. The twelve hallmarks of aging are a collection of cellular changes that drive the aging process. Two highly interconnected hallmarks of aging that drive the development and progression of sarcopenia and neurodegeneration are loss of proteostasis (protein homeostasis) and mitochondrial dysfunction. While progress has been made in understanding the etiology of chronic diseases, treatments for age-related chronic diseases affecting skeletal muscle and the brain are lacking. One reason for the lack of effective treatments in humans is the absence of preclinical animal models that recapitulate human aging. However, our group previously identified the Hartley guinea pig as a novel model of brain and skeletal muscle aging. We then treated these guinea pigs with a phytochemical compound to delay the onset and/or slow the progression of brain and skeletal muscle aging. Through the experiments in this dissertation, I observed that: 1.) phytochemical compounds, branded as Protandim, can improve mechanisms of proteostasis independent of changes in mitochondrial respiration in muscle precursor cells; 2.) the phytochemical compound, branded as PB125, can improve mechanisms of skeletal muscle proteostasis in the Hartley guinea pig; 3.) PB125 can also decrease neuroinflammation in the Hartley guinea pig; and 4.) despite the lack of declines in hippocampal mitochondrial respiration with age, Hartley guinea pigs exhibit decreased mitochondrial efficiency. Collectively, this dissertation builds on prior work suggesting that the Hartley guinea pig is a valuable model to test preclinical interventions.