Matching Items (30)
Description
The NLR family, pyrin domain-containing 3 (NLRP3) inflammasome is essential for the innate immune response to danger signals. Importantly, the NLRP3 inflammasome responds to structurally and functionally dissimilar stimuli. It is currently unknown how the NLRP3 inflammasome responds to such diverse triggers. This dissertation investigates the role of ion flux in regulating the NLRP3 inflammasome. Project 1 explores the relationship between potassium efflux and Syk tyrosine kinase. The results reveal that Syk activity is upstream of mitochondrial oxidative signaling and is crucial for inflammasome assembly, pro-inflammatory cytokine processing, and caspase-1-dependent pyroptotic cell death. Dynamic potassium imaging and molecular analysis revealed that Syk is downstream of, and regulated by, potassium efflux. Project 1 reveals the first identified intermediate regulator of inflammasome activity regulated by potassium efflux. Project 2 focuses on P2X7 purinergic receptor-dependent ion flux in regulating the inflammasome. Dynamic potassium imaging revealed an ATP dose-dependent efflux of potassium driven by P2X7. Surprisingly, ATP induced mitochondrial potassium mobilization, suggesting a mitochondrial detection of purinergic ion flux. ATP-induced potassium and calcium flux was found to regulate mitochondrial oxidative signaling upstream of inflammasome assembly. First-ever multiplexed imaging of potassium and calcium dynamics revealed that potassium efflux is necessary for calcium influx. These results suggest that ATP-induced potassium efflux regulates the inflammasome by calcium influx-dependent mitochondrial oxidative signaling. Project 2 defines a coordinated cation flux dependent on the efflux of potassium and upstream of mitochondrial oxidative signaling in inflammasome regulation. Lastly, this dissertation contributes two methods that will be useful for investigating inflammasome biology: an optimized pipeline for single cell transcriptional analysis, and a mouse macrophage cell line expressing a genetically encoded intracellular ATP sensor. This dissertation contributes to understanding the fundamental role of ion flux in regulation of the NLRP3 inflammasome and identifies potassium flux and Syk as potential targets to modulate inflammation.
ContributorsYaron, Jordan Robin (Author) / Meldrum, Deirdre R (Thesis advisor) / Blattman, Joseph N (Committee member) / Glenn, Honor L (Committee member) / Arizona State University (Publisher)
Created2015
Description
Studies have demonstrated that anthocyanins can function as antioxidants, reduce inflammation, and improve dyslipidemia. Tart cherries are anthocyanin-rich, making them particularly attractive as a functional food to improve cardiovascular disease (CVD) risk. There have been few published studies to date examining the impact of tart cherries on biomarkers of dyslipidemia and inflammation, particularly in overweight and obese individuals at high risk for these conditions. This study evaluated the effect of consuming 100% tart cherry juice daily on blood lipids including total cholesterol, low-density lipoprotein cholesterol (LDL-C), calculated very low density lipoprotein cholesterol (VLDL-C), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), and the CVD risk ratios, as well as the inflammatory biomarkers interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor-alpha (TNF-alpha), C-reactive protein (CRP), monocyte chemotactic protein-1 (MCP-1), and erythrocyte sedimentation rate (ESR) following a 4-week period. Based on the high anthocyanin content of tart cherries, it was hypothesized that the lipid and inflammatory profiles would be significantly improved following the intervention. A total of 26 men and women completed this 4-week randomized, single-blind, placebo-controlled, crossover study. Participants were randomized to drink either 8 ounces of placebo beverage or tart cherry juice daily for 4 weeks. Following a 4-week washout period, the alternate beverage was consumed. Ultimately, this investigation demonstrated no statistically significant alterations in any of the lipid or inflammatory biomarkers when analyzed across time and between interventions (p > 0.05). As expected, glucose and insulin parameters remained stable over the duration of the study, as well as self-reported physical activity level, total calorie consumption, and macronutrient intake. However, trans-fat was reported to be significantly higher during the cherry arm of the study as compared to the placebo arm (p < 0.05), potentially confounding other results. Although the results of this study were equivocal, it is feasible that a higher dose, longer treatment duration, or more susceptible target population may be required to elicit significant effects. Consequently, further investigation is necessary to clarify this research.
ContributorsColes, Katie (Author) / Martin, Keith R. (Thesis advisor) / Traustadottir, Tinna (Committee member) / Vega-Lopez, Sonia (Committee member) / Arizona State University (Publisher)
Created2012
Description
Approximately 2.8 million Americans seek medical care for traumatic brain injury (TBI) each year. Of this population, the majority are sufferers of diffuse TBI, or concussion. It is unknown how many more individuals decline to seek medical care following mild TBI. This likely sizeable population of un- or self-treated individuals combined with a lack of definitive biomarkers or objective post-injury diagnostics creates a unique need for practical therapies among diffuse TBI sufferers. Practical therapies stand to decrease the burden of TBI among those who would otherwise not seek treatment or do not meet clinical diagnostic criteria upon examination. For this unique treatment niche, practical therapies for TBI are defined as having one or more of the following qualities: common availability, easy administration, excellent safety profile, and cost-effectiveness. This dissertation identifies and critically examines the efficacy of four classes of practical treatments in improving rodent outcome from experimental diffuse traumatic brain injury.
Over-the-counter (OTC) analgesics, omega-3 fatty acids, specialized pro-resolving mediators (SPMs), and remote ischemic conditioning (RIC) were administered before or following midline fluid percussion injury. Behavioral, histological, and molecular analyses were used to assess treatment effects on functional outcome and secondary injury progression. Acute administration of common OTC analgesics had little effect on post-injury outcome in mice. Dietary supplementation with omega-3 fatty acid docosahexaenoic acid (DHA) prior to or following diffuse TBI significantly reduced injury-induced sensory sensitivity and markers of neuroinflammation with no effect on spatial learning. Intraperitoneal administration of omega-3 fatty acid-derived SPM resolvin E1 significantly increased post-injury sleep and suppressed microglial activation. Aspirin-triggered (AT) resolvin D1 administration improved both motor and cognitive outcome following diffuse TBI. RIC treatment in mice demonstrated little effect on functional outcome from diffuse TBI. Untargeted proteomic analysis of plasma samples from RIC-treated mice was used to identify candidate molecular correlates of RIC. Identification of these candidates represents a vital first step in elucidating the neuroprotective mechanisms underlying RIC. The overall findings suggest that omega-3 fatty acid supplementation, SPM administration, and RIC may serve as effective practical therapies to reduce the somatic, cognitive, and neurological burden of diffuse TBI felt by millions of Americans.
Over-the-counter (OTC) analgesics, omega-3 fatty acids, specialized pro-resolving mediators (SPMs), and remote ischemic conditioning (RIC) were administered before or following midline fluid percussion injury. Behavioral, histological, and molecular analyses were used to assess treatment effects on functional outcome and secondary injury progression. Acute administration of common OTC analgesics had little effect on post-injury outcome in mice. Dietary supplementation with omega-3 fatty acid docosahexaenoic acid (DHA) prior to or following diffuse TBI significantly reduced injury-induced sensory sensitivity and markers of neuroinflammation with no effect on spatial learning. Intraperitoneal administration of omega-3 fatty acid-derived SPM resolvin E1 significantly increased post-injury sleep and suppressed microglial activation. Aspirin-triggered (AT) resolvin D1 administration improved both motor and cognitive outcome following diffuse TBI. RIC treatment in mice demonstrated little effect on functional outcome from diffuse TBI. Untargeted proteomic analysis of plasma samples from RIC-treated mice was used to identify candidate molecular correlates of RIC. Identification of these candidates represents a vital first step in elucidating the neuroprotective mechanisms underlying RIC. The overall findings suggest that omega-3 fatty acid supplementation, SPM administration, and RIC may serve as effective practical therapies to reduce the somatic, cognitive, and neurological burden of diffuse TBI felt by millions of Americans.
ContributorsHarrison, Jordan L (Author) / Lifshitz, Jonathan (Thesis advisor) / Neisewander, Janet (Thesis advisor) / Stabenfeldt, Sarah (Committee member) / Willyerd, Frederick A (Committee member) / Pirrotte, Patrick (Committee member) / Arizona State University (Publisher)
Created2017
Description
The prevalence of obesity and obesity-related disorders have increased world-wide. In the last decade, the intestinal microbiome has become a major indicator of metabolic and gastrointestinal health. Previous research has shown that high-fat diet (HFD) consumption can alter the microbial composition of the gut by increasing the abundance of gram-positive bacteria associated with the onset of obesity and type 2 diabetes. Although, the most common form of obesity and metabolic syndrome intervention is exercise and diet, these recommendations may not improve severe cases of obesity. Thus, an important relevance of my project was to investigate whether the intake of an organometallic complex (OMC) would prevent the onset of metabolic and gastrointestinal complications associated with high-fat diet intake. I hypothesized that the consumption of a HFD for 6 weeks would promote the development of metabolic and gastrointestinal disease risk factors. Next, it was hypothesized that OMC treatment would decrease metabolic risk factors by improving insulin sensitivity and decreasing weight gain. Finally, I hypothesized that HFD-intake would increase the abundance of gram-positive bacteria associated with gastrointestinal disease. My preliminary data investigated the effects of a 6-week HFD on the development of hepatic steatosis, intestinal permeability and inflammation in male Sprague Dawley rats. I found that a 6-week HFD increases hepatic triglyceride concentrations, plasma endotoxins and promotes the production of pro-inflammatory cytokines in the cecum wall. I then investigated whether OMC treatment could prevent metabolic risk factors in male Sprague-Dawley rats fed a HFD for 10 weeks and found that OMC can mitigate risk factors such hyperglycemia, liver disease, impaired endothelial function, and inflammation. Lastly, I investigated the effects of a 10-week HFD on the gastrointestinal system and found an increase in liver triglycerides and free glycerol and alterations of the distal gut microbiome. My results support the hypothesis that a HFD can promote metabolic risk factors, alter the gut microbiome and increase systemic inflammation and that OMC treatment may help mitigate some of these effects. Together, these studies are among the first to demonstrate the effects of a soil-derived compound on metabolic complications. Additionally, these conclusions also provide an essential basis for future gastrointestinal and microbiome studies of OMC treatment.
ContributorsCrawford, Meli'sa Shaunte (Author) / Sweazea, Karen L (Thesis advisor) / Deviche, Pierre (Thesis advisor) / Al-Nakkash, Layla (Committee member) / Whisner, Corrie (Committee member) / Hyatt, Jon-Philippe (Committee member) / Arizona State University (Publisher)
Created2019
Description
There has long been a link tied between obesity and such pathological conditions as nonalcoholic fatty liver disease and type two diabetes. Studies have shown that feeding rats a diet high in fat results in hepatic steatosis and steatohepatitis. Using a novel short term diet of six weeks with male adolescent Sprague-Dawley rats, our laboratory sought to investigate the early effects of high fat intake on the liver. Prior findings in our laboratory found that a high fat diet (HFD) leads to nonalcoholic fatty liver disease as well as other symptoms of metabolic syndrome. This study hypothesized that rats fed a 60% HFD for 6 weeks, unlike a high sucrose or standard chow diet, would have an elevated expression of pro-inflammatory cytokines associated with steatohepatitis. TNF-α, TLR4 and XBP1 were chosen for their link to hepatic inflammation. The results of this study found that contrary to the hypothesis, the high fat diet did not induce significant changes in the expression of any inflammatory marker in comparison to a high sucrose or control chow diet.
ContributorsCalhoun, Matthew (Author) / Sweazea, Karen (Thesis director) / Deviche, Pierre (Reviewer) / Barrett, The Honors College (Contributor)
Created2015-05
Description
One of the most prominent biological challenges for the field of drug delivery is the blood-brain barrier. This physiological system blocks the entry of or actively removes almost all small molecules into the central nervous system (CNS), including many drugs that could be used to treat diseases in the CNS. Previous studies have shown that activation of the adenosine receptor signaling pathway through the use of agonists has been demonstrated to increase BBB permeability. For example, regadenoson is an adenosine A2A receptor agonist that has been shown to disrupt the BBB and allow for increased drug uptake in the CNS. The goal of this study was to verify this property of regadenoson. We hypothesized that co-administration of regadenoson with a non-brain penetrant macromolecule would facilitate its entry into the central nervous system. To test this hypothesis, healthy mice were administered regadenoson or saline concomitantly with a fluorescent dextran solution. The brain tissue was either homogenized to measure quantity of fluorescent molecule, or cryosectioned for imaging with confocal fluorescence microscopy. These experiments did not identify any significant difference in the amount of fluorescence detected in the brain after regadenoson treatment. These results contradict those of previous studies and highlight potential differences in injection methodology, time windows, and properties of brain impermeant molecules.
ContributorsWohlleb, Gregory Michael (Author) / Sirianni, Rachael (Thesis director) / Stabenfeldt, Sarah (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2015-05
Description
Neuroinflammation is an important secondary injury response occurring after traumatic brain injury (TBI). Anxiety-like disorders are commonly exacerbated after TBI and are mediated through the amygdala; however, the amygdala remains understudied despite its important contribution in processing emotional and stressful stimuli. Therefore, we wanted to study neuroinflammation after experimental TBI using midline fluid percussion in rodent models. We assessed microglia morphology over time post-injury in two circuit related nuclei of the amygdala, the basolateral amygdala (BLA) and central amygdala of the nucleus (CeA), using skeletal analysis. We also looked at silver staining and glial fibrillary acidic protein (GFAP) to evaluate the role of neuropathology and astrocytosis to evaluate for neuroinflammation in the amygdala. We hypothesized that experimental diffuse TBI leads to microglial activation in the BLA-CeA circuitry over time post-injury due to changes in microglial morphology and increased astrocytosis in the absence of neuropathology. Microglial cell count was found to decrease in the BLA at 1 DPI before returning to sham levels by 28 DPI. No change was found in the CeA. Microglial ramification (process length/cell and endpoints/cell) was found to decrease at 1DPI compared to sham in the CeA, but not in the BLA. Silver staining and GFAP immunoreactivity did not find any evidence of neurodegeneration or activated astrocytes in the respectively. Together, these data indicate that diffuse TBI does not necessarily lead to the same microglial response in the amygdala nuclei, although an alternative mechanism for a neuroinflammatory response in the CeA likely contributes to the widespread neuronal and circuit dysfunction that occurs after TBI.
ContributorsHur, Yerin (Author) / Newbern, Jason (Thesis director) / Thomas, Theresa Currier (Committee member) / Beitchman, Joshua (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Vascular inflammation is a key component for cerebrovascular disease and ischemic injury is suggested to be a significant contributor, resulting in either myocardial ischemia or stroke. A strong inflammatory response is characterized by the release of inflammatory cytokines, thus producing and/or activating pro-inflammatory proteins in the cell. Our previous studies have demonstrated that hypoxia plus glucose deprivation (HGD), an in vitro model of ischemia, increases the proinflammatory mediator, cyclooxygenase-2 levels (COX-2), in vascular tissues. Nuclear factor kappa B (NF-κB) activation is an upstream transcription factor of COX-2 and had been suggested to be involved in “sterile” inflammation in experimental stroke models. Mechanisms underlying the development and progression of inflammation in the cerebrovasculature following ischemic injury in human tissue has not been addressed. Thus, the purpose of this study was to examine the impact of HGD on NF-κB expression and activation in human brain vascular smooth muscle cells (HBVSMC). In addition, we assessed pro-inflammatory mediator levels of downstream NF-κB transcription products, COX-2 and iNOS, and level of its upstream receptor, TLR4. Primary HBVSMC at passage 7 were treated with normoxia (room air) or HGD (1% O2). Following exposure to HGD (3h), cells were isolated, homogenized, and total protein content determined. Lysates, either whole cell or nuclear and cytosolic fractions, were prepped for western blot and analysis. Anti-α-smooth muscle actin was used to verify HBVSMC origin and -actin was used as a loading control. NF-κBp65, phosphorylated NF-κBp65, COX-2, and TLR4 protein levels were all measured post HGD. NF-κBp65 total protein was expressed in HBVSMC and a trend for an increase in levels following HGD was observed. Indirect activation of pNF-kBp65 was assessed via nuclear fractionation studies and was increased following HGD. Lamin AC was used to verify nuclear fractionation. Additional findings suggested that HBVSMC expressed TLR4 however, total protein levels of TLR4 were not altered by HGD. COX-2 and iNOS protein levels were also increased following HGD. In conclusion, these studies indicate that HGD alters proinflammatory enzyme levels, potentially by altering NF-κBp65 activation in human vascular smooth muscle cells. Funding Support: University of Arizona Sarver Heart Center and University of Arizona Valley Research Project Grant VRP P1 (RG).
ContributorsRahman, Sanna (Author) / Sweazea, Karen (Thesis director) / Gonzales, Rayna (Committee member) / Li, Yu-Jing (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
The purpose of this cookbook is to provide pre-diabetic, type 1 and type 2 diabetics with a foundation of recipes. These recipes have been created with the intent of regulating inflammation which can be caused by such metabolic abnormalities. I want to educate patients who suffer from these conditions that there are several ingredients that work alongside their condition rather than feeling that they are limited to foods and recipes. I want to increase patients moral and self-efficacy to explore and work with new ingredients. These series of recipes should be used as a guide to trying new foods however patients should know that they are able to add their own ingredients that are suitable to their liking or condition.
ContributorsBhuyan, Nikita (Author) / Grant, Shauna (Thesis director) / Morse, Lisa (Committee member) / School of Nutrition and Health Promotion (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
Alzheimer’s disease (AD) is a progressive cognitive and behavior disorder that is characterized by the deposition of extracellular Aβ plaques, intracellular neurofibrillary tangles, and neuroinflammation. Aβ is generated by cleavage of the amyloid precursor protein (APP) by β-secretase (BACE1) and, subsequently, y- secretase. In recent years, there has been an increasing interest in studying and understanding inflammation as a therapeutic target for AD. Inflammation manifests in the brain in the form of activated microglia and astrocytes. These cells are able to release high levels of inflammatory cytokines such as Tumor Necrosis Factor-α (TNF-α). TNF-α is a major cytokine, which is involved in early inflammatory events and plays a role in the progression of AD pathology. There are currently no treatments that target chronic neuroinflammation. However, previous work in our laboratory with transgenic mice modeling AD suggested that the anti-cancer drug lenalidomide could lower neuroinflammation and slow AD progression, though the cellular and molecular mechanisms are yet to be elucidated. Here we hypothesized that lenalidomide can modulate TNF-α production in microglia and decrease amyloidogenesis. Using immortal cell lines mimicking several brain cell types, we discovered that lenalidomide is likely to decrease inflammation by modulating microglia cells rather than neurons or astrocytes. In addition, the drug may prevent the overexpression of BACE1 upon inflammation, thus blocking the overproduction of Aβ. If confirmed, these results could lead to a better understanding of how inflammation regulates Aβ synthesis and provide novel cellular and molecular therapeutic targets to control the progression AD.
ContributorsGujju, Manasa (Author) / DeCourt, Boris (Thesis director) / Olive, M. Foster (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05