Matching Items (9)
Filtering by
- Creators: Barrett, The Honors College
- Creators: Kavazanjian, Edward
- Creators: Allenby, Braden
- Creators: Cadillo – Quiroz, Hinsby
Neuroinflammation Following Experimental Diffuse Brain Injury in Pre-pubertal and Peri-pubertal Rats
Description
Traumatic brain injury is the leading cause of mortality and morbidity in children and adolescents. Adolescence is a critical time in development where the body and brain undergoes puberty, which not only includes reproductive maturation, but also adult social and cognitive development. Brain-injury-induced disruptions can cause secondary inflammation processes and as a result, pediatric TBI can lead to significant life-long and debilitating morbidities that continue long after initial injury. In this study, neuroinflammation following diffuse brain injury was explored in prepubertal and peripubertal rats using an adapted method of midline fluid percussion injury (mFPI) for juvenile rats to further understand the relationship between pediatric TBI and puberty disruption due to endocrine dysfunction. We expect the adapted mFPI model to be effective in producing diffuse, moderate brain injury in juvenile rats and hypothesize that pre-pubertal rats (PND35) will have increased neuroinflammation compared to peri-pubertal rats (PND17) and shams because of the potential neuroprotective nature of sex steroids. Male Sprague-Dawley rats (n=90) were subjected to either a diffuse midline fluid percussion injury (mFPI) or sham injury at post-natal day (PND) 17 (pre-puberty) or PND35 (peri-puberty). Animals were sacrificed at different time points defined as days post injury (DPI) including 1DPI, 7DPI and 25DPI to represent both acute and chronic time points, allowing for comparisons within groups (injury vs. sham) and across groups (PND17 vs PND35). Body weight of the rats was measured postoperatively at various time points throughout the study to follow recovery. Tissue was collected and subjected to Heamatoxylin and Eosin (H&E) stain to visualize histology and evaluate the application of diffuse mFPI to juvenile rats. In addition, tissue underwent immunohistochemical analysis using 3,3'-diaminobenzidine (DAB) to stain for ionized calcium binding proteins (Iba1) in order to assess injury-related neuroinflammation in the form of microglia activation. Diffuse brain injury using the mFPI model did not affect rat body weight or cause overt cell death, suggesting adaption of the adult mFPI model for juvenile rats is representative of moderate diffuse brain injury. In addition, diffuse TBI lead to morphological changes in microglia suggesting there is an increased inflammatory response following initial insult, which may directly contribute to improper activation of pubertal timing and progression in adolescent children affected. Since there is little literature on the full effects of puberty dysfunction following TBI in the pediatric population, there is a significant need to further assess this area in order to develop improved interventions and potential therapies for this affected population.
ContributorsNewbold, Kelsey Bevier (Author) / Newbern, Jason (Thesis director) / Rowe, Rachel (Committee member) / Ortiz, J. Bryce (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Tumor associated microglia-and-macrophages (TAMS) may constitute up to 30% of the composition of glioblastoma. Through mechanisms not well understood, TAMS are thought to aid the progression and invasiveness of glioblastoma. In an effort to investigate properties of TAMS in the context of glioblastoma, I utilized data from a PDGF-driven rat model of glioma that highly resembles human glioblastoma. Data was collected from time-lapse microscopy of slice cultures that differentially labels glioma cells and also microglia cells within and outside the tumor microenvironment. Here I show that microglia localize in the tumor and move with greater speed and migration than microglia outside the tumor environment. Following previous studies that show microglia can be characterized by certain movement distributions based on environmental influences, in this study, the majority of microglia movement was characterized by a power law distribution with a characteristic power law exponent lower than outside the tumor region. This indicates that microglia travel at greater distances within the tumor region than outside of it.
ContributorsJuliano, Joseph Dominic (Author) / Kostelich, Eric (Thesis director) / Nagy, John (Committee member) / Swanson, Kristin (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2013-12
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
Currently conventional Subtitle D landfills are the primary means of disposing of our waste in the United States. While this method of waste disposal aims at protecting the environment, it does so through the use of liners and caps that effectively freeze the breakdown of waste. Because this method can keep landfills active, and thus a potential groundwater threat for over a hundred years, I take an in depth look at the ability of bioreactor landfills to quickly stabilize waste. In the thesis I detail the current state of bioreactor landfill technologies, assessing the pros and cons of anaerobic and aerobic bioreactor technologies. Finally, with an industrial perspective, I conclude that moving on to bioreactor landfills as an alternative isn't as simple as it may first appear, and that it is a contextually specific solution that must be further refined before replacing current landfills.
ContributorsWhitten, George Avery (Author) / Kavazanjian, Edward (Thesis director) / Allenby, Braden (Committee member) / Houston, Sandra (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2013-05
Characterization and Manipulation of Microbiomes From Arid Landfills for Improved Methane Production
Description
Environmentally harmful byproducts from solid waste’s decomposition, including methane (CH4) emissions, are managed through standardized landfill engineering and gas-capture mechanisms. Yet only a limited number of studies have analyzed the development and composition of Bacteria and Archaea involved in CH4 production from landfills. The objectives of this research were to compare microbiomes and bioactivity from CH4-producing communities in contrasting spatial areas of arid landfills and to tests a new technology to biostimulate CH4 production (methanogenesis) from solid waste under dynamic environmental conditions controlled in the laboratory. My hypothesis was that the diversity and abundance of methanogenic Archaea in municipal solid waste (MSW), or its leachate, play an important role on CH4 production partially attributed to the group’s wide hydrogen (H2) consumption capabilities. I tested this hypothesis by conducting complementary field observations and laboratory experiments. I describe niches of methanogenic Archaea in MSW leachate across defined areas within a single landfill, while demonstrating functional H2-dependent activity. To alleviate limited H2 bioavailability encountered in-situ, I present biostimulant feasibility and proof-of-concepts studies through the amendment of zero valent metals (ZVMs). My results demonstrate that older-aged MSW was minimally biostimulated for greater CH4 production relative to a control when exposed to iron (Fe0) or manganese (Mn0), due to highly discernable traits of soluble carbon, nitrogen, and unidentified fluorophores found in water extracts between young and old aged, starting MSW. Acetate and inhibitory H2 partial pressures accumulated in microcosms containing old-aged MSW. In a final experiment, repeated amendments of ZVMs to MSW in a 600 day mesocosm experiment mediated significantly higher CH4 concentrations and yields during the first of three ZVM injections. Fe0 and Mn0 experimental treatments at mesocosm-scale also highlighted accelerated development of seemingly important, but elusive Archaea including Methanobacteriaceae, a methane-producing family that is found in diverse environments. Also, prokaryotic classes including Candidatus Bathyarchaeota, an uncultured group commonly found in carbon-rich ecosystems, and Clostridia; All three taxa I identified as highly predictive in the time-dependent progression of MSW decomposition. Altogether, my experiments demonstrate the importance of H2 bioavailability on CH4 production and the consistent development of Methanobacteriaceae in productive MSW microbiomes.
ContributorsReynolds, Mark Christian (Author) / Cadillo-Quiroz, Hinsby (Thesis advisor) / Krajmalnik-Brown, Rosa (Thesis advisor) / Wang, Xuan (Committee member) / Kavazanjian, Edward (Committee member) / Arizona State University (Publisher)
Created2022
Description
Neuroinflammation contributes significantly to the pathogenesis of Alzheimer’s and Parkinson’s diseases. However, the inflammatory pathways contributing to neurodegeneration are not well understood. Moreover, there is a need to identify changes in inflammatory signaling that may occur early in disease progression to identify potential targets for therapeutic intervention. An important step towards addressing this need is understanding how the extracellular vesicles (EVs) released by microglia can be detected in the periphery. For microglia, phagocytic macrophages, and CD 14+ monocytes share many genes and membrane- bound proteins, and there is currently no method to distinguish microglia EVs from those generated by macrophages or monocytes. Therefore, this study aims to identify membrane-bound proteins unique to microglia EVs to enable their reliable isolation. Liquid-chromatography tandem mass spectrometry analysis was used to detect proteins in the EVs from both normal and disease-associated human stem-cell differentiated microglia (iMGL), and human induced pluripotent stem cell-derived CD 14+ monocytes and macrophages. We identified 23 proteins unique to the microglial EVs, eight of which localize to the membrane and may be potential targets for isolation. This investigation also used RNA sequencing to gain insight into the contents of DAM-like and control iMGL EVs and of microglia and white blood cells in Alzheimer’s disease. We propose that the contents of microglial EVs isolated from peripheral compartments will provide crucial insight for understanding the current inflammatory state of CNS microglia. This approach could provide a means to track changes in microglial activation over time, which is critical for understanding the progression of neuroinflammatory diseases like Alzheimer's and Parkinson's. Additionally, it may offer insights into potential therapeutic targets for modulating neuroinflammation.
ContributorsLopatin, Ulia (Author) / Mastroeni, Diego (Thesis director) / Velazquez, Ramon (Committee member) / Van Keuren-Jensen, Kendall (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2024-05
Description
Zero-Valent Metals (ZVM) are highly reactive materials and have been proved to be effective in contaminant reduction in soils and groundwater remediation. In fact, zero-Valent Iron (ZVI) has proven to be very effective in removing, particularly chlorinated organics, heavy metals, and odorous sulfides. Addition of ZVI has also been proved in enhancing the methane gas generation in anaerobic digestion of activated sludge. However, no studies have been conducted regarding the effect of ZVM stimulation to Municipal Solid Waste (MSW) degradation. Therefore, a collaborative study was developed to manipulate microbial activity in the landfill bioreactors to favor methane production by adding ZVMs. This study focuses on evaluating the effects of added ZVM on the leachate generated from replicated lab scale landfill bioreactors. The specific objective was to investigate the effects of ZVMs addition on the organic and inorganic pollutants in leachate. The hypothesis here evaluated was that adding ZVM including ZVI and Zero Valent Manganese (ZVMn) will enhance the removal rates of the organic pollutants present in the leachate, likely by a putative higher rate of microbial metabolism. Test with six (4.23 gallons) bioreactors assembled with MSW collected from the Salt River Landfill and Southwest Regional Landfill showed that under 5 grams /liter of ZVI and 0.625 grams/liter of ZVMn additions, no significant difference was observed in the pH and temperature data of the leachate generated from these reactors. The conductivity data suggested the steady rise across all reactors over the period of time. The removal efficiency of sCOD was highest (27.112 mg/lit/day) for the reactors added with ZVMn at the end of 150 days for bottom layer, however the removal rate was highest (16.955 mg/lit/day) for ZVI after the end of 150 days of the middle layer. Similar trends in the results was observed in TC analysis. HPLC study indicated the dominance of the concentration of heptanoate and isovalerate were leachate generated from the bottom layer across all reactors. Heptanoate continued to dominate in the ZVMn added leachate even after middle layer injection. IC analysis concluded the chloride was dominant in the leachate generated from all the reactors and there was a steady increase in the chloride content over the period of time. Along with chloride, fluoride, bromide, nitrate, nitrite, phosphate and sulfate were also detected in considerable concentrations. In the summary, the addition of the zero valent metals has proved to be efficient in removal of the organics present in the leachate.
ContributorsPandit, Gandhar Abhay (Author) / Cadillo – Quiroz, Hinsby (Thesis advisor) / Olson, Larry (Thesis advisor) / Boyer, Treavor (Committee member) / Arizona State University (Publisher)
Created2019
Time-Lapse Visualization of Microglia Cell Processes using Fluorescent Miniature (Miniscope) Imaging
Description
In the United States, an estimated 2 million cases of traumatic brain injury (TBI) resulting in more than 50,000 deaths occur every year. TBI induces an immediate primary injury resulting in local or diffuse cell death in the brain. Then a secondary injury occurs through neuroinflammation from immune cells in response to primary injury. Microglia, the resident immune cell of the central nervous system, play a critical role in neuroinflammation following TBI. Microglia make up 10% of all cells in the nervous system and are the fastest moving cells in the brain, scanning the entire parenchyma every several hours. Microglia have roles in both the healthy and injured brain. In the healthy brain, microglia can produce neuroprotective factors, clear cellular debris, and organize neurorestorative processes to recover from TBI. However, microglia mediated neuroinflammation during secondary injury produces pro-inflammatory and cytotoxic mediators contributing to neuronal dysfunction, inhibition of CNS repair, and cell death. Furthermore, neuroinflammation is a prominent feature in many neurodegenerative diseases such as Alzheimer’s, and Parkinson’s disease, of which include overactive microglia function. Microglia cell morphology, activation, and response to TBI is poorly understood. Currently, imaging microglia can only be performed while the animal is stationary and under anesthesia. The Miniscope technology allows for real-time visualization of microglia in awake behaving animals. The Miniscope is a miniature fluorescent microscope that can be implanted over a craniectomy to image microglia. Currently, the goals of Miniscope imaging are to improve image quality and develop time-lapse imaging capabilities. There were five main sub-projects that focused on these goals including surgical nose cone design, surgical holder design, improved GRIN lens setup, improved magnification through achromatic lenses, and time-lapse imaging hardware development. Completing these goals would allow for the visualization of microglia function in the healthy and injured brain, elucidating important immune functions that could provide new strategies for treating brain diseases.
ContributorsNelson, Andrew Frederick (Author) / Stabenfeldt, Sarah (Thesis director) / Lifshitz, Jonathan (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Traumatic brain injury (TBI)—sudden impact or acceleration trauma to the head—is a major cause of death and disability worldwide and is particularly amplified in pediatric cases. TBI is the leading cause of mortality and morbidity in children and adolescents. Adolescence is a critical time where the brain undergoes cognitive development and brain injury-induced disruptions to these processes can lead to life-long debilitating morbidities. The aim of this study was to determine if exercising spatial and contextual memory circuits using a novel rehabilitation strategy called Peg Forest Rehabilitation (PFR) could mitigate the onset of injury-induced cognitive deficits in juvenile rats subjected to diffuse TBI. The PFR aims to synthesize neuroplasticity-based enrichment to improve cognitive outcomes after TBI. We hypothesized that PFR treatment would mitigate the onset of brain injury-induced cognitive deficits and reduce neuroinflammation. Juvenile male Sprague-Dawley rats (post-natal day 35) were subjected to diffuse traumatic brain injury via midline fluid percussion injury or a control surgery. One-week post-injury, rats were exposed to PFR or cage control exploration (15 min/day). PFR allowed free navigation through random configuration of the peg-filled arena for 10 days over 2 weeks. Control rats remained in home cages in the center of the arena with the peg-board removed for 15 min/day/10 days. One-week post-rehabilitation (one-month post-injury), cognitive performance was assessed for short-term (novel object recognition; NOR), long-term (novel location recognition; NLR), and working (temporal order recognition; TOR) memory performance, calculated as a discrimination index between novel and familiar objects. Tissue was collected for immunohistochemistry and stained for ionized calcium binding proteins (Iba-1) to visualize microglia morphology, and somatostatin. PFR attenuated TBI-induced deficits on the NOR task, where the TBI-PFR treatment group spent significantly more time with the novel object compared with the familiar (*p=0.0046). Regardless of rehabilitation, brain-injured rats had hyper-ramified microglia in the hypothalamus indicated by longer branch lengths and more endpoints per cell compared with uninjured shams. Analysis of somatostatin data is ongoing. In this study, passive, intermittent PFR that involved dynamic, novel spatial navigation, prevented TBI-induced cognitive impairment in adolescent rats. Spatial navigation training may have clinical efficacy and should be further investigated.
ContributorsAftab, Umar (Author) / Rowe, Rachel K. (Thesis director) / Newbern, Jason M. (Thesis director) / Ortiz, J. Bryce (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05