Barriers to Delivering Prevention and Treatment for HIV and Opioid Use Disorder for Individuals on Probation

Type: Undergraduate
Author(s): Angela Rique Psychology Kevin Knight Psychology Jen Pankow Psychology
Advisor(s): Jen Pankow Psychology Kevin Knight Psychology
Location: SecondFloor, Table 9, Position 2, 1:45-3:45

Opioid Use Disorder (OUD) and HIV are both critical and interconnected public health issues, particularly among individuals who are justice-involved. Individuals under community supervision face significant obstacles in accessing the prevention and treatment services necessary for both OUD and HIV. Although harm reduction strategies such as Medication Assisted Treatment (MAT) for OUD and pre-exposure prophylaxis (PrEP) for HIV prevention have proven effective, these interventions remain underutilized and difficult to access. This research explores barriers to service delivery that service providers face in delivering OUD and HIV care to justice-involved individuals with substance use disorder. Qualitative analysis of data sourced from the National Institute on Drug Abuse (NIDA)-funded study, Addressing Risk through Community Treatment for Infectious Disease and Opioid Use Disorder Now (ACTION) was coded with deductive methods. By identifying systemic, structural, and social barriers, the study aims to understand the challenges that affect care delivery. Key findings included stigma surrounding PrEP, lack of awareness about available services, delays in ART (anti-retroviral treatment) initiation, transportation barriers, judicial resistance to MAT and punitive legal approach to OUD. Addressing these barriers is essential to improving health outcomes and reducing the impact of HIV and OUD in justice-involved individuals, drawing on service provider insights to inform future policy changes.

Survival and seduction: Understanding the adaptive link between threat and sexual openness

Type: Undergraduate
Author(s): Kaylee Sanchez Psychology Melissa Brillhart Psychology
Advisor(s): Sarah Hill Psychology
Location: Third Floor, Table 6, Position 1, 11:30-1:30

For much of human evolutionary history, women have relied on their men for direct benefits like resources and protection. Importantly, men are unlikely to provide these benefits without receiving something in return. One potential strategy women may use to secure these resources is offering men sexual access in exchange for investment. Given that sex is a highly valuable resource for men, as their reproductive success largely depends on the number of women who are willing to grant him sexual access, they should be willing to accept obtaining sexual access in exchange for their investment. For women in harsh environments, having an investing male figure is particularly crucial to survival. As such, we should expect that women’s sexual openness may vary depending on whether they are in a stable or harsh environment as being more sexually open may be advantageous for women who are in harsh environments. Thus, the present research aims to examine the impact of environmental harshness on women’s sexual openness. We predict that women who are in harsh environments will be more sexually open than women who are in stable environments. Data are forthcoming.

Beliefs About Emotion and Emotion Regulation Goals

Type: Undergraduate
Author(s): Vladyslav Shelashskyi Psychology Cathy Cox Psychology
Advisor(s): Cathy Cox Psychology
Location: SecondFloor, Table 2, Position 3, 11:30-1:30

Emotion regulation capability is a major contributor to various areas of functioning, including well-being and mental health(citation). Previous research (Rusk et al., 2011) shows that people differ on how motivated they are to demonstrate their ability to control their emotions (performance goals) and how motivated they are to learn to control their emotions better (learning goals). The current study explored the relationship between beliefs about controllability and usefulness of emotions and how much the participants endorsed higher performance and learning emotion regulation goals. The study also explored how emotion regulation goals and emotion beliefs correlated with various indicators of well-being. The initial correlational study showed that believing emotions can be controlled moderately predicted higher performance-avoidance goals for emotion regulation, while believing that emotions were generally useful had a weak negative association with learning emotion regulation goals. Additionally, higher emotion controllability beliefs, as well as higher performance-avoidance goals, predicted lower well-being. A second study was conducted to assess the causal relationship between emotion controllability beliefs and performance-avoidance emotion regulation goals.

Changes in Wellness Among Women Who Discontinue Using Hormonal Birth Control

Type: Undergraduate
Author(s): Adison Sokolosky Psychology Melissa Brillhart Psychology
Advisor(s): Sarah Hill Psychology
Location: Third Floor, Table 7, Position 2, 11:30-1:30

Research looking at the association between hormonal birth control and mental health outcomes has primarily looked at what happens to women when they start using hormonal birth control. However, researchers have not begun to delve deep into the influence of discontinuing hormonal birth control on women’s mental health outcomes. Therefore, this study aimed to address this gap in the literature by investigating mental health outcomes of those who have discontinued hormonal birth control. Participants included women who had never used hormonal birth control (HBC), were currently using hormonal birth control, or had discontinued using hormonal birth control. All participants answered survey questions related to their current mental health outcomes. Results revealed that there were no differences in trait anxiety between never HBC users, current HBC users, or previous HBC users. However, there were differences in depression levels among the groups, such that individuals who had never used HBC reported higher levels of depression than previous HBC users. Therefore, these findings suggest that hormonal birth control usage may act as a neuroprotective intervention against depression during a developmentally critical time in which mood disorders commonly arise.

A Zebra Finch's Lateral Eye View of Self Recognition: Studying Cognition Through Songs and Mirror

Type: Undergraduate
Author(s): Maria Solis Psychology Soseh Asadoorian Psychology Kevin Bien Psychology Andrew Magee Psychology Dimitri McLain Psychology Hannah Scheffer Psychology Samantha Shah Chemistry & Biochemistry
Advisor(s): Brenton Cooper Psychology
Location: Third Floor, Table 1, Position 3, 11:30-1:30

Self-recognition is a key indicator of higher cognitive processing and is atypical in children with autism spectrum disorder. A normal hallmark of typical social development requires knowledge of self and others. Self-recognition has been tested in a variety of different species and has been seen in a small number of mammals, birds, and fish. It is classically demonstrated by visual recognition using the mirror mark test. Parishar et al. (2021) previously examined self-recognition in zebra finches (Taeniopygia guttata), and despite some potentially promising findings, none of the birds in their experiments passed the mirror mark test. This study sought to extend previous research by exploring whether zebra finches demonstrate self-recognition using a more thorough and exhaustive procedure exposing zebra finches to a mirror following the application of visible mark. Six male zebra finches were habituated to an experimental cage and were exposed to four different conditions (mirror, male bird, female bird, control). Then, two analyses were performed: Experiment 1 examined whether zebra finches change the spectrotemporal features of song in each of the four conditions, and Experiment 2 assessed whether birds attempted to inspect or remove a mark only visible when birds viewed their reflection in a mirror in each condition. Observations suggest that some birds may show attention towards the mark test because as seen by mark-directed behavior. Song characteristics will be explored to determine if zebra finches modify their song structure when facing a mirror compared to singing to a male bird, a female bird, or an empty cage (control). This would provide evidence supporting self-recognition if the singing behavior directed toward the mirror is distinct from that toward a conspecific. This study explores whether self-recognition is observed in zebra finches, providing insight into evolutionary and cognitive mechanisms of self-recognition that can be used for future studies in the neurobiology of social and cognitive behaviors.

Existential Isolation and Its Impact on Empathy and Perspective Taking

Type: Undergraduate
Author(s): Emily Spinning Psychology Cathy Cox Psychology Matthew Espinosa Psychology
Advisor(s): Cathy Cox Psychology
Location: Third Floor, Table 9, Position 2, 1:45-3:45

Existential Isolation and Its Impact on Empathy and Perspective Taking

Existential Isolation (EI) is the experience of feeling as though you are alone in your experience of the world; and that those around you do not share or understand your experiences. Past research demonstrates that EI is associated with negative influences on personal well-being including: loneliness, depression, anxiety, and lower levels of self-esteem. The impact of EI on our interactions or perceptions of others is less known and understood. Individuals that feel existentially isolated perceive a disconnect between how they experience the world and how others experience the world. Due to this disconnect, people with higher levels of EI may have difficulty taking the perspective of others or “walking in someone else’s shoes”. Perspective taking is a vital cognitive factor for feeling empathetic towards others. To explore if EI is associated with less empathy for others due to a difficulty in perspective taking, 186 undergraduate students were presented with three short stories depicting someone experiencing stress (e.g., recently experienced the death of a parent), and asked to try taking the perspective of the people in the stories. Results indicated that people who reported greater feelings of EI also reported greater difficulty with perspective taking and, subsequently, reported feeling less empathy for the people in the stories. These findings suggest that EI may inhibit people’s feelings of empathy due to increasing their difficulty with perspective taking. The implications of these findings for the role of EI in helping and supporting behaviors are discussed.

Existential Isolation and Its Impact on Empathy and Perspective Taking

Type: Undergraduate
Author(s): Emily Spinning Psychology Cathy Cox Psychology Matthew Espinosa Psychology
Advisor(s): Cathy Cox Psychology

Existential Isolation and Its Impact on Empathy and Perspective Taking

Type: Undergraduate
Author(s):
Advisor(s): Cathy Cox Psychology

The Independent Relationships Between Emotion Dysregulation and Anxiety on Marijuana Use for Youth in the Legal System

Type: Undergraduate
Author(s): Jessie Swartz Psychology Danica Knight Psychology Lillyan Shelley Psychology
Advisor(s): Danica Knight Psychology
Location: Third Floor, Table 9, Position 1, 1:45-3:45

In conjunction with the legalization of medical marijuana, there has been an increase in recreational marijuana use among youth. In 2016, marijuana use for youth in the legal system (YLS) hit a high of 64%, which far exceeded the 11% rate for youth outside the legal system. Youth that frequently or occasionally use marijuana are linked to adverse health problems, including both physical and emotional, and have poor school outcomes. Prior research has found that youth who use marijuana are more susceptible to emotional dysregulation and higher levels of anxiety. Higher anxiety levels have been linked to greater marijuana use, more significant anxiety symptoms, and increases in anxiety over time. This is concerning as research shows that youth with higher levels of anxiety sensitivity, or fear of anxiety, used marijuana to detach or manage emotional distress. Due to the risks associated with cannabis use, this study examined marijuana use among a sample of YLS, specifically looking at its connection to both emotion dysregulation and anxiety. Data were utilized over three timepoints (i.e., baseline, 3-month follow-up, and 6-month follow-up) from a 5-year longitudinal study. Consistent with prior research, it is expected that there would be a positive relationship between anxiety and marijuana use, as well as emotion dysregulation and marijuana use. Utilizing Pearson’s correlations, results indicated a significant negative relationship between marijuana use and the emotion dysregulation subscale of nonacceptance at baseline. However, there were no significant relationship between marijuana use and anxiety. At month 3 follow-up, there were significant positive relationships between marijuana use and anxiety, as well as marijuana use and emotion dysregulation for total scores and the nonacceptance subscale. At the month 6 follow-up, results indicated a positive relationship between marijuana use and anxiety. However, there was no longer a significant relationship between marijuana use and emotion dysregulation. These preliminary results suggest there is a complicated relationship between emotion dysregulation and anxiety when it comes to marijuana use. Future research should continue examining these relationships to better inform intervention work.

The unique role of thought suppression in predicting panic symptom severity

Type: Undergraduate
Author(s): Michael Wrucke Psychology Thomas Sease Psychology
Advisor(s): Thomas Sease Psychology Cathy Cox Psychology
Location: Basement, Table 8, Position 1, 1:45-3:45

Panic disorder is a debilitating mental health disorder characterized by recurrent panic attacks, fear of future panic attacks and maladaptive behavioral changes. While only 4.7% of Americans will battle panic disorder in their lifetime, 27.3% of Americans will experience at least one panic attack. Cognitive models of panic attacks have historically emphasized the role of anxiety sensitivity in predicting symptoms, but other transdiagnostic variables, such as thought suppression, have yet to be explored. The purpose of this study was to test the ability of thought suppression to predict panic symptom severity above and beyond other predictors. To do this, we recruited participants (N = 161) on Cloud Research using Amazon's Mechanical Turk (MTurk) Toolkit. Participants completed an online survey consisting of self-report measures of panic symptom severity, thought suppression, anxiety sensitivity, and trait anxiety. Results of simultaneous and hierarchical multiple regressions revealed that thought suppression was a significant positive predictor of panic symptom severity and accounted for additional variance in the model above and beyond anxiety sensitivity and trait anxiety. This unique finding suggests that perhaps attempts to suppress anxious or catastrophic thoughts strengthens them and feeds the panic cognitive loop. It also supports the exploration of acceptance-based interventions to address thought suppression differently than traditional cognitive-behavioral therapy.

Effects of Sensory Modality in a Visual Working Memory Task in Pigeons

Type: Undergraduate
Author(s): Hampton Zidlicky Psychology Ashley Kyle Psychology John Solorzano Restrepo Psychology Brianna Vaughan Psychology
Advisor(s): Kenneth Leising Psychology
Location: SecondFloor, Table 1, Position 1, 11:30-1:30

Prior research has found that visual cues presented before (pre) or after (retro) an object improve object properties recognition, like identity (what it is) and spatial location (where it is), in humans (Griffin & Nobre, 2003) and monkeys (Brady & Hampton, 2018). However, this has not yet been tested in other species or using other cue modalities (e.g., auditory). The current experiment will analyze the effect of visual and auditory cues on object recognition in 6 pigeons, explicitly examining how these cues influence identity and spatial location processing in a visual working memory task.

Pigeons will perform a change detection task,in a Plexiglas chamber with a monitor, touch screen, and speakers. In each trial, the subject will peck a white crosshair on the center of the screen to start. After 1500 ms, a sample pair of colored circles will appear on the left and right sides of the screen for 5000 ms. After a 1500 ms delay, a test stimulus will be displayed on the screen’s left or right side. Pigeons must compare the test stimulus to the sample previously presented on the same side of the screen. During some trials, pigeons will receive pre- or retro-cue signaling which sample stimulus will be tested (e.g., the one displayed on the left). For half of the pigeons, the cues will be different frequency sounds (auditory group), and for the rest, colored backgrounds (visual group). It is predicted that the auditory group will have higher accuracy than the visual group, suggesting auditory cues may enhance recognition of visual objects more than visual cues.

Goats in the Garden: Sustainable Grazing for Ecological Restoration and Land Management

Type: Undergraduate
Author(s): Taryn Mitchell Ranch Management Sebastian Alarcon Ranch Management Brooke Best Ranch Management
Advisor(s): Jeffrey Geider Ranch Management
Location: SecondFloor, Table 4, Position 1, 1:45-3:45

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 contamination of a High Arctic invertebrate food web and potential risk to arachnivorous birds

Type: Undergraduate
Author(s): Aleah Appel Biology Benjamin D. Barst Biology Kurt Burnham Biology Morgan Capone Biology Matthew Chumchal Biology Maddy Hannappel Biology Reuben Heine Biology Benjamin Katzenmeyer Biology Kevin Myer Biology Iris Schmeder Biology Sarah Scott Biology Benjamin Strang Biology Emma Sullivan Biology Tyler Williams Biology
Advisor(s): Matt Chumchal Biology
Location: First Floor, Table 6, Position 2, 1:45-3:45

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.

REFINING METHODS FOR ISOLATING, PURIFYING, AND CHARACTERIZING BACTERIOPHAGES.

Type: Undergraduate
Author(s): Maykeling Arauz Gutierrez Biology Sophie Cronk Biology Aeron Pennington Biology
Advisor(s): Shauna McGillivray Biology
Location: Second Floor, Table 3, Position 2, 1:45-3:45

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.

Testing the Effect of Novel Antioxidant Compounds on the Activation of the Antioxidant Gene Activator Nrf2

Type: Undergraduate
Author(s): Robert Benafield Biology
Advisor(s): Giridhar Akkaraju Biology Kayla Green Chemistry & Biochemistry
Location: Third Floor, Table 2, Position 3, 11:30-1:30

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.

Molecular details of the BRCA1 interaction with estrogen receptor alpha (ERα)

Type: Undergraduate
Author(s): Aiza Butt Chemistry & Biochemistry Emma Alexander Physics & Astronomy Zygmunt Gryczynski Physics & Astronomy Mikaela Stewart Biology
Advisor(s): Mikaela Stewart Biology
Location: Basement, Table 15, Position 2, 11:30-1:30

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.

Investigating the effects of phosphorylation on the BRCA1/PALB2 interaction

Type: Undergraduate
Author(s): Audrey Dolt Biology Hayes Martin Biology
Advisor(s): Mikaela Stewart Biology
Location: Basement, Table 15, Position 1, 11:30-1:30

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

Type: Undergraduate
Author(s): Jessica Guilhas Biology Kyle Gallegos Biology Mariah Green Biology Jacob Malmquist Biology Julio Manceras Biology Shauna McGillivray Biology
Advisor(s): Shauna McGillivray Biology
Location: Second Floor, Table 1, Position 2, 1:45-3:45

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.

HT-22 Hippocampal Neurons as a Model System to Study Oxidative Stress and the Nrf2 pathway

Type: Undergraduate
Author(s): Alia Hannon Biology
Advisor(s): LaTrina Parker Hall Interdisciplinary Michael Chumley Biology
Location: Basement, Table 1, Position 1, 11:30-1:30

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

Type: Undergraduate
Author(s): Gabby Linares Biology
Advisor(s): Dr. Floyd Wormley Biology
Location: Basement, Table 4, Position 3, 11:30-1:30

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.

Testing the Ability of Novel Drugs to Modulate LPS-Induced TNF-alpha Production in BV-2 Microglial Cells

Type: Undergraduate
Author(s): Fabian Lopez Chemistry & Biochemistry Cameron Bowers Biology
Advisor(s): Giridhar Akkaraju Biology
Location: Basement, Table 1, Position 2, 1:45-3:45

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.

In Vitro Study of the Effect of PALB2 Phosphorylation on BRCA1-PALB2 Dimerization

Type: Undergraduate
Author(s): Hayes Martin Biology Mikaela Stewart Biology
Advisor(s): Mikaela Stewart Biology
Location: Third Floor, Table 1, Position 3, 1:45-3:45

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.

Repurposing Drugs: Ritanserin as a Potential Novel Antibiotic

Type: Undergraduate
Author(s): Sheridan O'Coyne Biology Alex Caron Biology Shauna McGillivray Biology Mikaela Stewart Biology
Advisor(s): Shauna McGillivray Biology
Location: First Floor, Table 5, Position 2, 1:45-3:45

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.

The Effect of Novel Anti-Inflammatory Compounds on NFkB Activation in TNF-a-Induced HEK293 Cells

Type: Undergraduate
Author(s): Kaelie Paugh Biology
Advisor(s): Giridhar Akkaraju Biology
Location: Third Floor, Table 1, Position 1, 11:30-1:30

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.

Anti-Virulence as a New Antibiotic Class: Searching for Novel Virulence Genes in B. anthracis

Type: Undergraduate
Author(s): Abi Plylar Biology
Advisor(s): Shauna McGillivray Biology
Location: Basement, Table 9, Position 1, 1:45-3:45

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.