Invasive plant species significantly impact native ecosystems by outcompeting indigenous flora, reducing biodiversity, and disrupting the delicate ecological equilibrium. In collaboration with the Fort Worth Botanic Garden, this research study evaluated the efficacy of utilizing sheep and goats as a sustainable grazing strategy to mitigate invasive plant species within the garden.

Vegetation analyses, specifically vegetative cover and species richness, of pre- and post-grazing indicated an initial decline in plant species richness. However, based on prior studies, plant succession and resilience are anticipated to rebound in the grazed areas over time (Booth & Skelton, 2009; Rathfon et al., 2021). The research findings also indicated environmental and operational benefits, including reduced labor costs, minimized chemical inputs, decreased noise pollution, and mimicked historical ecological processes that have been found to improve soil health and biodiversity. The findings from this research emphasize the targeted use of livestock grazing as a sustainable land management practice. This case study highlights the benefits of integrating controlled livestock grazing into public garden maintenance protocols. Furthermore, this research contributes to the existing literature regarding sustainable land management and the role of livestock in controlling invasive species and restoring ecosystems.

References

Booth, A. L., & Skelton, N. W. (2009). The use of domestic goats and vinegar as municipal weed control alternatives. Environmental Practice, 11(1), 3-16. DOI:10.1017/S1466046609090012

Rathfon, R. A., Greenler, S. M., & Jenkins, M. A. (2021). Effects of prescribed grazing by goats on non‐native invasive shrubs and native plant species in a mixed‐hardwood forest. Restoration Ecology, 29(4).

https://doi.org/10.1111/rec.13361

Mercury (Hg) emitted in temperate and tropical regions can be transported to the Arctic where it is disproportionately deposited across the landscape. In aquatic systems, inorganic forms of Hg can be methylated to the toxic and bioaccumulative species, methylmercury (MeHg). In temperate zones, riparian spiders that specialize in consuming adult insects emerging from aquatic systems (e.g., Araneidae and Tetragnathidae) accumulate high concentrations of MeHg and have been used as sentinels of MeHg contamination. In addition, these taxa frequently accumulate concentrations of MeHg that may pose a risk to arachnivorous songbirds. Although these taxa are useful sentinels in risk assessment studies in the temperate zone, they are not present in the High Arctic. The purpose of the present study was to assess the potential of a generalist spider species, the Arctic wolf spider (Pardosa glacialis), to serve as a sentinel of Hg pollution in the Arctic. In summer 2022, we collected 1460 wolf spiders and 8090 emergent aquatic insects (Chironomidae) from six ponds in Northwest Greenland (centered around 76.5° N, 68.8° W). Spiders and insects were composited by body size and collection site. Hg concentrations for spiders and insects ranged from 230 - 1100 ng/g dry weight (dw) and 75 - 297 ng/g dw, respectively. Spider Hg concentrations were strongly correlated with insect Hg concentrations (R2 = 0.83), suggesting that wolf spiders can be used as sentinels of Hg contamination in Arctic lentic systems and had Hg concentrations that exceeded risk thresholds for arachnivorous songbirds.

Bacteriophages, the most abundant biological entities on Earth, specifically infect bacteria. These viruses initiate the lytic cycle, hijacking the cellular machinery of their bacterial hosts to replicate, which ultimately leads to the host's destruction. Phage therapy has shown promising results in treating antibiotic-resistant infections, though clinical trials are ongoing to fully establish its safety and efficacy. Identifying suitable phages is crucial in developing successful therapy due to the specificity of bacteriophage-host interactions.
Our study refined methods for isolating and studying bacteriophages against Enterobacter aerogenes, a critical ESKAPE pathogen contributing to antibiotic resistance. We evaluated two isolation techniques: the overnight enrichment assay and direct isolation via the whole plate spotting assay. Our comparison found an advantage of the direct isolation method—it not only matched the efficacy of the overnight enrichment but surpassed it by offering accelerated results and minimizing resource utilization. A key refinement for purification was the incorporation of calcium chloride into the soft agar, which markedly enhanced plaque clarity and visibility. Moreover, our exploration of DNA extraction techniques revealed the superiority of zinc chloride precipitation over commercial kits, with the former delivering higher DNA yield and purity.
We isolated three phages, K-1, BB-1, and M-1, effective against E. aerogenes. Noteworthy, phage BB-1 exhibited a rapid lytic cycle, clearing plates in under 10 hours. Future research will focus on examining their infectivity across Enterobacter strains, lysis of host cells, and absorption rates. We will also analyze their genome sequences to determine their novelty and potential for addressing antibiotic resistance.

The presence of Reactive Oxidative Species (ROS) in the brain have been linked to the etiology of Alzheimer’s disease and neurodegeneration. In this project, novel antioxidant Indole derivative drugs were tested on BV-2 microglial cells using RT-qPCR to assess their ability to activate antioxidant gene expression. Nuclear factor erythroid 2–related factor 2 (Nrf2) is a gene transcription factor that is activated by oxidative stress and binds to a sequence called the Antioxidant Response Element (ARE), a region upstream of the DNA promoter sequence. Nrf2 activates transcription of antioxidative genes. Based on theoretical docking studies, we hypothesize that the novel compounds will disrupt the interaction between Nrf2 and its inhibitor KEAP, releasing Nrf-2 and enabling it to translocate to the nucleus. The novel antioxidant drugs should either increase the transcription of Nrf2-activated genes or reduce overall levels of antioxidative stress within cells. We tested for antioxidant properties by measuring Hemeoxygenase-1 (HO-1) and Nrf2 mRNA levels in BV-2 cells in the presence of these compounds.

Estrogen receptor alpha (ERα) and BRCA1 play an important role in the development of breast cancer, and multiple pathways link these two proteins together. Previous studies have identified the ligand binding domain (LBD) of ERα and residues 1 through 258 of BRCA1 as important in the direct physical interaction between these two proteins. This study aimed to characterize the binding kinetics of this interaction in the presence and absence of 17β-estradiol (estrogen) with a shortened BRCA1 construct (residues 177-258); however, binding between ERα LBD and this BRCA1 construct could not be detected through fluorescence emission spectroscopy or isothermal titration calorimetry (ITC). Synthesizing ERα LBD presented challenges with low yield, so the purification protocol was refined to cool bacterial cultures at an OD600 of 0.2 during growth and add dithiothreitol during lysis for improved yield. A 24% decrease in fluorescence intensity upon addition of estrogen to ERα LBD confirmed the ligand-binding functionality of the protein. Additionally, Stern-Volmer studies verified that the estrogen binding site on ERα LBD is located in close vicinity to the tryptophan residues in the protein since fluorescence quenching was more efficient in the absence of estrogen. Finally, factors contributing to the absence of ERα-BRCA1 binding are discussed, including the length of the BRCA1 construct used or the potential necessity of an additional protein, BARD1.

BRCA1 and PALB2 proteins suppress tumor formation by promoting homologous recombination when DNA damage has occurred. Mutations in BRCA1 and PALB2 are associated with a higher prevalence of breast and ovarian cancers. Phosphorylation of BRCA1 and PALB2 occurs upon DNA damage and is vital for maintaining genomic integrity. The molecular mechanism of how phosphorylation directs the activation of these proteins is unknown. It is established that phosphorylation of BRCA1 and PALB2 occurs in or near the coiled-coil regions of both proteins. The proteins use this domain to heterodimerize, so we hypothesize that the phosphorylation events could promote efficient BRCA1/PALB2 interactions. Our study aims to determine the effect of phosphorylation on the BRCA1/PALB2 binding affinity. The serine and threonine residues that are phosphorylated on BRCA1 or PALB2 were mutated to a glutamic acid to mimic phosphorylation. Glutamic acid carries a negative charge and thus mimics the negative charge added to the protein upon phosphorylation. We overexpressed and purified the protein using a bacterial expression system and measured their heterodimerization affinity with isothermal titration calorimetry (ITC). We will share ITC data suggesting phosphorylation of PALB2 does not affect its binding affinity to BRCA1. The phosophomimicking mutations in BRCA1 have also been generated, both individually and in tandem, and we will share results from these binding studies that are ongoing and hypotheses generated from our results regarding phosphorylation as an activation switch to control BRCA1/PALB2 interactions.

The Identification of Novel Genes Related to Iron Acquisition in Bacillus Anthracis Sterne

Jessica Guilhas, Kyle Gallegos, Julio Manceras, Mariah Green, Jacob Malmquist, Shauna M. McGillivray

Bacillus anthracis, the causative agent of anthrax, is a spore-forming, gram-positive bacterium. Its virulence mechanisms are of interest due to its potential use as a biological weapon and high lethality. For B. anthracis to survive and reproduce in a host, it must evade the host's immune response and acquire nutrients. One important nutrient B. anthracis must acquire is iron. Iron is a limiting nutrient in the host because it is usually found sequestered to hemoglobin or bound to host proteins such as transferrin. To acquire iron, pathogens must strip it from the host proteins. To find genes important for iron acquisition from hemoglobin, we screened genetic mutants created through transposon mutagenesis. Media was chelated to remove all divalent cations, including iron, and then hemoglobin was added as the sole iron source. The mutants that were unable to grow were chosen to be tested in a larger volume hemoglobin assay. We confirmed the phenotype of several mutants using this larger volume assay and we are working to confirm the site of transposon disruption via PCR. The mutants thus identified include a mutation in a dUTPase gene and an L-aspartate oxidase gene, neither of which has been previously linked to iron acquisition from hemoglobin. Future directions include making independent mutations and/or complement the disrupted genes to confirm the gene disruption is linked to loss of iron acquisition from hemoglobin. This study allows for a further understanding of how B. anthracis acquires iron and sheds new light on potentially novel virulence mechanisms.

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by the formation of amyloid beta (Aβ) plaques in the brain and is the seventh leading cause of death in the United States. Chronic inflammation and oxidative stress associated with AD leads to neuronal cell death. A cellular protective mechanism against oxidative stress involves the Nuclear factor erythroid 2-related factor (Nrf2) pathway. Nrf2 is responsive to the reactive oxygen species (ROS) produced when the cell is under oxidative stress, leading to its translocation into the nucleus where it activates transcription of genes that produce antioxidant enzymes like heme oxygenase-1 (HO-1). To study this pathway in neurons, our lab chose to use the mouse hippocampal HT-22 neuronal cell line. Our previous attempts to grow these cells in culture proved difficult, leading us to hypothesize that providing a growth-enhancing surface of collagen would provide a more stable surface in which to propagate these cells. Here we show that HT-22 cells grown on rat tail collagen provide a model system to investigate the Nrf2 pathway. We also demonstrate that HT-22 cells are viable on tissue culture plastics without the need for collagen.

Exploring EncT Efflux Pump Functionality and their Role in Lipid Signaling
Gabby Linares, Sawyer Diaz, Natalia Castro-Lopez, Floyd Wormley Jr.
Department of Biology, Texas Christian University

Cryptococcus neoformans, a fungal pathogen mainly affecting immunocompromised individuals, has sparked interest in lipid signaling research due to its role in pathogenesis. Eicosanoids, derived from fatty acids, are crucial in virulence and immune modulation; with C. neoformans lacking human enzyme homologs for eicosanoids biosynthesis, we want to identify the enzymes involved in the biosynthesis of cryptococcal eicosanoids and test their potential as antifungal targets. This project is focused on the EncT gene, encoding an efflux pump, which we observed to be upregulated in response to lipid precursors. Using CRISPR technology, we produced an EncT knockout (KO) strain and the corresponding reconstituted strain, aiming to discern shifts in virulence factors like melanin production, capsule formation, and urea production, among others, comparing the knockout, wild-type, and reconstituted strains and, subsequently, employing a mouse model of pulmonary cryptococcosis to delve deeper into virulence dynamics. Our initial results show early production of melanin EncT KO compared to the WT strain and no changes in the capsule formation or growth at 37°C.

Fabian Lopez1,2, Cameron Bowers3, Giri Akkaraju1,3, Texas Christian University1, Department of Chemistry and Biochemistry2, Department of Biology3

Microglial cells are resident immune cells in the human brain that mediate the inflammatory response. The molecular hallmarks of Alzheimer’s Disease are neurofibrillary tangles and amyloid-B protein aggregates. In response to this buildup of these proteins, microglial cells release pro-inflammatory cytokines, such as TNF-alpha to recruit other microglia to this site of injury. However, when the microglia are unable to remove the waste, there is then a continuous cycle of cytokine secretion and microglia recruitment that leads to chronic inflammation. The NF-kB pathway is activated when molecules of bacterial cell walls, such as LPS, bind to toll-like receptor 4 (TLR4) in infected cells. This results in the translocation of NF-kB to the nucleus where it induces the expression of the TNF-alpha gene. In order to attenuate this response, our collaborators at P2D Biosciences and the Lab of Dr. Kayla Green at TCU have designed anti-inflammatory drugs. BV-2 cells are microglial mouse cells that are used as a model to test the efficacy of these drugs. The cytotoxicity of these drugs was first measured using an MTT assay to ensure that any observed reductions in secretions of cytokines such as TNF-alpha can be attributed to inhibition of inflammatory signaling pathways by the drug. An Enzyme-Linked Immunosorbent Assay (ELISA) was utilized to quantify and compare the levels of TNF-alpha in control and drug treated groups. The preliminary results suggest that Dr. Green’s drug, PK60, leads to a reduction in the levels of TNF-alpha secreted by BV-2 cells. This work serves as basis for employing techniques to investigate how upstream messengers of the NF-kB pathway are affected by PK60 to identify its mechanism of action.

BRCA1 and PALB2 are two proteins that bind to efficiently repair DNA damage through homologous recombination. Inability for these proteins to dimerize due to genetic variations can increase an individual’s risk of developing breast and ovarian cancer. Currently, most PALB2 genetic variants are classified as variants of unknown significance (VUSs) due to insufficient data to predict pathogenicity. In vivo methods to predict pathogenicity of these variants are time consuming and costly. As a result, we aimed to create a high-throughput and cell-free assay to test the effect of VUSs on the BRCA1-PALB2 binding interaction. Importantly, we wanted to recreate any relevant cellular conditions to obtain the most accurate data, and currently, the effect of PALB2 phosphorylation on the BRCA1-PALB2 binding interaction in vitro is unknown. To determine if phosphorylation affects the binding interaction, we mimic the phosphorylation states of PALB2 using site-directed mutagenesis and test their effect on BRCA1 binding using isothermal titration calorimetry. Our results indicate a surprising finding: PALB2 phosphorylation does not significantly alter the strength of the BRCA1-PALB2 binding interaction with minimized constructs in vitro. Thus, we hypothesize it is not critical to recreate the phosphorylation states of PALB2 when testing the effect of VUSs on the BRCA1-PALB2 binding interaction.

With the surge of multidrug resistant bacteria and increasing antibiotic resistance, there is a critical need for the development of new drug therapies. A new antimicrobial technique revolves around targeting virulence factors, which enable the bacterial pathogen to evade host immune defenses. Inhibitors that target pathogenicity hinder the capacity of the bacterium to cause an infection, thus allowing the host immune system to better clear the infection. In this study, we aim to inhibit the ClpXP protease, a highly conserved intracellular protease involved in virulence in different bacterial pathogens. Previous studies have shown that inhibition of ClpX completely attenuates virulence in Bacillus anthracis, rendering the pathogen more susceptible to cell envelope targeting antibiotics such as penicillin, daptomycin and LL-37. Computational modeling was performed and ten commercially available inhibitors with predicted activity against ClpX were identified, with ritanserin showing the most promise. In this study we explore the antimicrobial effects of ritanserin, a previously identified serotonin 2A receptor antagonist that underwent clinical trials as a potential treatment for schizophrenia and substance dependence. We hypothesized that if ritanserin inhibits ClpX in B. anthracis Sterne it should mimic the phenotype of the knockout clpX mutant, ΔclpX. We found that ritanserin increased WT Bacillus anthracis susceptibility to the cell envelope targeting antibiotics penicillin and daptomycin. Future studies will look at interactions host defenses such as antimicrobial peptides including LL-37. This demonstrates that ritanserin could be potentially repurposed as an antibacterial drug with the potential to be used by itself or in combination with antibiotics.

Alzheimer’s Disease (AD), the most common form of Dementia, is a brain disorder that affects memory, cognition, and behavior. It currently affects 6.7 million Americans in the United States and interferes with daily life. Neuroinflammation in the brain is thought to worsen symptoms and drive the progression of the disease. Inflammation is mediated by the transcription factor NFkB, which typically leads to transcription of pro-inflammatory cytokines, including TNF-alpha and IL-1B. The transcription of these cytokines can lead to a cycle of chronic inflammation if left unregulated. In collaboration with P2D Biosciences and the Green Lab, we focused on testing compounds for their ability to reduce inflammation. Some of the compounds tested here have been shown to reduce cognitive defects in a mouse model of AD. In this study we are trying to understand the mechanism of action of these drugs. We are looking at the effect on the transcription factor NFkB.

B. anthracis is a gram-positive, spore-forming bacterial pathogen and the causative agent of the deadly disease, anthrax. This pathogen produces a lethal infection due to the potency of its virulence factors in inflicting harm upon and defending against their host. While anthrax toxin and capsule encoded in the B. anthracis plasmids are well-studied, there is minimal research into the over 5,000 chromosomal genes. To identify potential chromosomal virulence factors, a B. anthracis Sterne strain transposon mutant library containing thousands of randomly disrupted genomes was created and previously used to successfully screen for loss of virulence-associated phenotypes. In our current screen, we examined attenuation of mutants exposed to oxidative stress in the form of H2O2. ROS are released by innate immune response cells and destroy invading pathogens lacking adequate defense mechanisms. While there are some known antioxidant-encoding genes in B. anthracis, like the catalase gene, we predict there are others that may influence the bacteria’s susceptibility to ROS. To search for additional genes, we screened over 1,300 transposon mutants using H2O2 and selected mutants with growth attenuation compared to wild-type B. anthracis Sterne. Mutants with increased H2O2 susceptibility were further tested to confirm in-vitro phenotypes. Ultimately, we want to screen selected mutants in the G. mellonella invertebrate infection models to prioritize mutants with both in-vitro and in-vivo phenotypes. Our goal is to discover novel virulence factors while also developing validated methods and procedures to study B. anthracis pathogenesis.

Mercury (Hg) is released into the environment by coal-fired power plants, artisanal gold mines, and other human activities. Aquatic bacteria then convert the inorganic mercury into a highly toxic compound called methyl mercury. The methyl mercury builds up through bioaccumulation and biomagnification causing consumption bans for several species of fish in Texas. Dragonfly larvae can be used as bioindicators for methyl mercury contamination in aquatic ecosystems. The carnivorous diet of larvae leads to the bioaccumulation of measurable amounts of methyl mercury. Fort Worth ISD students have been working with TCU on the USGS citizen science - “The Dragonfly Mercury Project”. Dragonfly larvae are collected by students using dipnets at the Fort Worth Nature Center and Refuge along with National Parks across the United States. The larvae are placed in Ziploc bags with a label indicating the family, total length, date and location. Students wore gloves and followed a strict protocol to avoid contamination of samples. The samples are frozen and shipped with dry ice to a USGS lab for analysis. We report the data collected during 2018, 2020, 2021 and 2022 at the Fort Worth Nature Center and Refuge. We sampled three different sites on the refuge, Lake Worth (n=62, x̄=20.5ppb), Lotus Marsh(n=62, x̄=61.4ppb), and West Pasture Pond(n=66, x̄=34.4ppb).

Exploring the effects of a comprehensive Mediterranean diet verses a typical American diet on peripheral inflammation and the expression of inflammation-related genes in the dorsal hippocampus
Catherine Shoffner, Mary Skrabanek, Raleigh Robinson, Caleb Pryor, Morgan Bertrand, Vivienne Lacy, Paige Braden Kuhle, Gary Boehm, Michael Chumley
Approximately 72% of Americans are overweight or obese, partially due to the consumption of a Western diet (WD). The highly-processed WD is composed of simple carbohydrates, sugars, and saturated fats. The WD has been identified as a risk factor for Alzheimer’s disease (AD) due to the elevated levels of pro-inflammatory cytokines following long-term diet consumption. In contrast to the WD, the Mediterranean diet (MD) is a plant-based, mostly unsaturated fat diet. Research has shown that it is crucial to consume a balanced omega-6 to omega-3 ratio of 1:1 or 2:1, like that in the MD, as elevated ratios found in the WD lead to increased inflammation.
Previous studies generally utilize an extremely high-fat Western rodent diet that does not resemble that of the typical American. Thus, our lab designed two novel macronutrient-matched diets that mimic typical American or Mediterranean diets. In the current study, we examined the effects of the typical American diet (TAD) versus the MD in relation to pro-inflammatory cytokine production in serum and gene expression in the dorsal hippocampus of C57BL/6J mice. Following six months of TAD or MD consumption, the mice were treated with one intraperitoneal injection of lipopolysaccharide (LPS) or saline 4 hours prior to euthanasia. In comparison to the MD, mice consuming the TAD had increased expression and levels of pro-inflammatory cytokines in the dorsal hippocampus and serum, respectively.

In attempt to characterize the toxic effects of effluents discharged into surface waters, a previous study has shown crude oil contamination alters both mortality and hatching success among two model organisms: inland silversides and sheepshead minnows. Through toxicity testing it has become apparent that pollutants have the capacity to significantly alter growth and development of marine life. Specifically, it was found that exposure delayed the time of hatch or didn’t allow for hatch at all, and the unhatched embryos were less likely to survive. In addition, differences in both hatch and mortality were observed between the two organisms. Since the experimental conditions of the previous study were held constant for both groups the observed differences must be a result of a physiological difference, and a key distinction between the two species may lie in the differential use of the yolk sac. In the early stages of development marine organisms utilize the yolk sac as an internal source of energy prior to free feeding. It has been indicated that energy reserves and rate of depletions can differ between species. To determine the rate of yolk sac depletion in both inland silversides and sheepshead minnows, a total of 48 embryos per species were collected and raised to hatch. A subset of larvae at 24- to 96-hours post hatch were collected and the presence or absence of the yolk sac was determined. It was found that the yolk sac was depleted in 100% of the larvae 24-hours earlier for inland silversides as compared to sheepshead minnows. This observed difference shows a difference in the rates of energy reserve use and is indicative of a dissimilar response to external stressors, such as crude oil. These results may provide evidence of a mechanisms by which marine organisms experience differential hatch success and mortality when exposed to pollutants. Future research efforts might focus on the effect of yolk sac depletion as a key physiological distinction between species when outlining adverse effects of additional chemical exposures.

Oncorhynchus mykiss, commonly known as rainbow trout, exhibit partial migratory behavior, in which some individuals in a population will opt to migrate, whereas others do not. Consequently, there are two ecotypes of O. mykiss: the non-migratory rainbow trout (also known as residents) and the migratory steelhead (also known as migrants). Previous evidence generated from our lab demonstrated that various loci in the rainbow trout genome segregate between resident rainbow trout and migrant steelhead trout in the Sashin creek system of Alaska. A unique feature of the Sashin system is that a series of waterfalls separate the lake and stream, thereby inhibiting gene flow between the lake between migratory stream individuals and resident lake individuals. However, it is still unknown whether these same genetic markers also segregate between behaviors in other freshwater systems. Therefore, the goal of my research project is to use DMAS-qPCR to genotype known migrant individuals and known resident individuals from Little Sheep Creek, Oregon. This population is geographically separated from the Sashin Creek watershed and differs from Sashin in that both life histories can and do interbreed. From this project, I will be able to deduce 1) if genetic markers associated with life history development are shared across freshwater drainages and 2) to test if there is evidence of assortative mating (i.e., residents mating with residents and migrants mating with migrants) within the Little Sheep Creek system which would suggest genetic differences between life histories.

Mercury (Hg) is a global contaminant produced primarily by anthropogenic activities (i.e. coal-fired power plants, artisanal gold-mining operations) and is found in all freshwater systems. Primary producers (e.g., algae) and aquatic organisms that consume algae (e.g., emerging aquatic insects) are exposed to mercury through their diet. As adults, these emerging insects leave freshwater systems to reproduce, transferring both energy and Hg from their aquatic environment to the adjacent terrestrial environment. We assessed the emergence biomass of aquatic insects and insect–mediated Hg flux from 6 ponds in Northwest Greenland from July 1-30, 2022. Emergence biomass ranged from 0.09 to 176.91 mg/m2/day and insect-mediated Hg flux ranged from 0.009 ng/m2/day to 23.67 ng/m2/day across all ponds for the sampling period. This study suggests that small pongs in the High Arctic are important sources of both energy and contaminants to food webs in surrounding terrestrial ecosystems.

Alzheimer’s disease (AD) is ranked as the seventh leading cause of death in the US with over 6 million Americans currently diagnosed, and that number is projected to reach about 13 million by 2050. AD is currently believed to be caused by numerous factors ranging from genetics, lifestyle, and environmental conditions. The exact pathogenesis of AD remains uncertain, but the pathology of the disease includes the presence of amyloid beta (Aβ) plaques and neurofibrillary tangles composed of the protein tau in the brain. These are two proteins are normally found in the brains of healthy individuals, but amyloid-beta peptides are often degraded under normal conditions, while tau plays a role in stabilizing our cell’s cytoskeletal structures. In Alzheimer’s however, these proteins are misfolded and accumulate, causing disruptions in cell signaling and neuronal death, therefore worsening the disease. Aβ plaques also activate microglial cells, which produce cytokines and induce inflammation. Cytokines are signaling molecules produced by immune cells that mediate inflammatory signaling. Activation of an inflammasome complex found in microglial cells, NLRP3, leads to the production of the cytokine IL-1β which has been implicated in Alzheimer’s due to its ability to induce and maintain this chronic cycle of inflammation, and possibly results in more amyloid-beta deposition. Our research looks into the mode of action of novel anti-inflammatory drugs and their potential to reduce inflammation at the level of the NLRP3 inflammasome as a mechanism to slow down the progression of AD.
 

Alzheimer’s disease is the most common form of dementia and affects over 6 million Americans 65 and older. In the absence of a cure, addressing modifiable risk factors could potentially reduce the risk of AD development. There is an established relationship between diet and AD risk. For example, studies in rodents found that highly processed Western diets are associated with cognitive impairment and increased amyloid-beta in the hippocampus, a brain region critical for learning and memory. Conversely, plant-based diets like the Mediterranean diet (MD) have been shown to protect against cognitive impairment.

A key limitation in the scientific literature is that most animal studies have only examined the effects of extremely high-fat WD (providing over 40-60% kcal from fat), or a MD with only one or two key nutritional components. We aimed to fill a gap in the literature by designing a rodent diet that mimicked the typical American diet (TAD), rather than an exaggerated WD, and a macronutrient-matched MD. C57BL/6J mice were weaned onto one of the two diets at postnatal day 21. Following six months of diet, we conducted behavioral tests, including open field, elevated zero, and object-location memory task (OLMT). In comparison to the MD, mice consuming the TAD had decreased locomotor activity and exploratory behavior, increased anxiety-like behavior, and reduced spatial memory.

Mercury contamination is of increasing concern. As the earth’s temperature continues to rise, it is vital to study the trends of MeHg absorption. Continuing to gather MeHg absorption data in the Northwest part of Greenland will help to grow our understanding of MeHg trends in Arctic territories. This study will increase the amount of data collected on MeHg levels, allowing a more accurate comparison between MeHg level patterns and species behavior, breeding success, and death rates in Arctic bird species (Chastel et al., 2022). Understanding how MeHg contamination affects health and prosperity is critical, not only for the environment and animals but people as well, as these birds are often part of the native Greenlander diet (Hong et al. 2012; Johansen et al. 2004). Temporal monitoring is also highly beneficial for evaluating the efficacy of policies aiming to reduce anthropogenic Hg emissions (AMAP 2021).

Pyridinophane molecules have recently been shown to have both antioxidant and pharmacological properties suitable for therapeutic applications targeting neurodegenerative diseases, including Alzheimer’s Disease. We have synthesized derivatives of this parent molecule with added moiety substitutions. These substitutions are designed to enhance the permeability and antioxidant activity beyond that of the parent molecule in the hopes of producing a molecule suitable for pharmacological testing in animal models. To establish a principle between moiety location on the parent molecule and its activity, we have placed 8-hydroxyquinoline, a moiety established in our lab to improve the antioxidant activity of parent molecules, in varying locations. The results presented here will detail our evaluation of the substitution of 8-hydroxyquinoline in varying locations and its impact on the molecule’s permeability and reactivity through a series of statistics, including a DPPH assay, determination of logBB, and the determination of chelating equilibrium quotients at varying pH (“log beta”).

Alzheimer’s Disease (AD) affects over 6.5 million Americans over the age of 65. Previous research links AD with Amyloid-Beta-40 (AB40) aggregation in the brain, which creates neurotoxic plaques, associated with AD. A potential mechanism in the treatment of AD is using therapeutics that will prevent the formation of these plaques, which is possible with Metal Chelation Therapy.
Metal ion chelation ideally stops metal ions from aiding in the aggregation of AB40. However, to deliver metal chelating agents to the brain, a drug-delivery mechanism is required that will be able to deliver this medicine across the Blood-Brain Barrier. Porous silica is a potential drug delivery material due to its small particle size, high loading capacity, surface tunability, and biocompatibility. Along with these characteristics, porous silica can create a “sustained” release of a given drug, allowing for a slow and steady release profile, reducing the risks of medication side effects.
This project seeks to establish the optimal loading capacities of a class of potential metal ion chelate therapeutic molecules known as pyclens into porous silica, each with different pyridyl moieties and chemical functionalities along the rim of the molecule. Encapsulation efficiencies measurements for these pyclen derivatives reveal loading percentages in the 10-19% range, varying by pyclen identity. Additionally, release studies monitored diffusion over time to find which pyclen molecule achieved “sustained” release. All loaded pyclen species were able to show sustained release after 20 minutes, both in the presence and absence of copper (II) ions. Turbidity assays with AB40 present showed that all pyclen species decreased protein aggregation in the presence of copper (relative to non-pyclen controls), showing that all pyclen species were able to successfully prevent the aggregation of AB40 in the presence of copper.
Release studies in a more authentic BBB model remain to be completed.

Polyvinyl pyrrolidone (PVP) is a nonionic synthetic polymer often employed in drug formulations. Due to its hydrophilicity, it is often found in aqueous solutions where it can act as a solubilizing agent for organic molecules with poor water solubility. Interestingly, PVP also exhibits fluorescence in water. Furthermore, PVP fluorescence intensity is known to decrease as the concentration of salt increases. This effect has been attributed to the affinity of inorganic anions to PVP chains. In this poster, we examine the effect of an anionic surfactant, sodium dodecyl sulfate (SDS), on PVP fluorescence. In contrast with inorganic anions, we found that PVP fluorescence intensity increases with SDS concentration. We attribute this effect to the binding of SDS anions to PVP chains. This hypothesis is supported by a crystallization assay showing that PVP suppresses formation of SDS crystals. Our experimental results indicate that PVP fluorescence could be used to determine concentration of other types of anionic surfactants in water. These include perfluoroalkyl substances (PFAS), which are relevant environmental chemistry.