Student Presentations & Abstracts

 

 

Oral presentations 1: Biology & other: Zoom link

Moderator: Matthew M. & Avery V.

 

Sinchana Basoor (Biology)

Principal Investigator: Dr. James D. Stockand

Intracellular Regulation of Epithelial Na+ Channel (ENaC) by Ankyrin 3 and Casein Kinase 2

Hypertension affects roughly half of the adults in the United States and costs the nation nearly $130 billion every year. Defects in renal sodium transport may contribute to hypertension. The epithelial Na+ channel (ENaC), specific to the distal nephron, reabsorbs Na+ from urine and is regulated by several hormones, including aldosterone and vasopressin. While the function of ENaC is understood, its intracellular regulation remains unclear. Previous research has shown that binding motifs for ankyrin-3 (Ank3) overlap with a casein kinase 2 (CK2) phosphorylation site in β-ENaC’s C terminus (βC). CK2 is activated by PKA, a component of the vasopressin receptor signaling pathway. We hypothesize that CK2 phosphorylation mediates ENaC translocation to the plasma membrane via Ank3, a cytoskeletal transport protein, thereby increasing ENaC activity. To understand this, we tested the interactions of βC with Ank3 and CK2 using biophysical methods. We also examined the physiological implications of CK2 activation via Gs-DREADD mice (a model for the Gαs-cAMP vasopressin signaling pathway selectively activated by CNO). Metabolic cage, immunofluorescence, and patch clamping studies were conducted on Gs-DREADD mice. Urine sodium excretion was reduced after treatment with CNO compared to wild-type mice. Immunofluorescence microscopy showed colocalization of ENaC and Gs-DREADD in the distal tubule. Patch clamping experiments showed that CNO-induced activation of Gs-DREADD led to increased ENaC activity. These results are consistent with a model in which vasopressin increases ENaC trafficking via interactions between CK2 and Ank3. These interactions with ENaC provide potential inhibition targets for blood pressure control.

 

Sanjanaa Senthilkumar (Biology)

Principal Investigator: Dr. Ramon Lavado

Effects of dietary natural products on the fatty acid accumulation in the human liver cell line HepaRG

Non-alcoholic fatty liver disease (NAFLD) and its progressive form non-alcoholic steatohepatitis (NASH) are rapidly becoming among the top causes of cirrhosis, hepatocellular carcinoma, and indications for liver transplantation in the US. Dietary natural compounds have been shown to act through various mechanisms to prevent and improve NAFLD in patients. Still, to date, there is no in vitro study that 1) has used a good model for NAFLD and 2) shown the mechanism of action of those natural compounds. This study investigates the effects of three natural compounds on fatty acid accumulation in the human liver cell line HepaRG. The selected compounds are the indole-3-carbinol, a compound found in vegetables like broccoli and used to prevent several types of cancer; cannabidiol, the active ingredient in cannabis-derived from the hemp plant; and trans-resveratrol, a natural compound present in grapes, red wine, and berries with anticancer properties. HepaRG has characteristics similar to primary human hepatocytes upon differentiation and has been reported as a good NAFLD model. For each compound, cytotoxicity was assessed over a broad range of concentrations (0.1 mM to 0.01 nM). LC50s were in the high uM range (around 30 mg/L), showing the low toxicity of these compounds. Cells were exposed to oleic acid (100 mM) as a positive control, and co-exposures of oleic acid and the selected compounds were done in HepaRG differentiated cells. Fatty acid bioaccumulation was assessed by oil red O (colorimetric) and BODIPY (fluorescent) staining. Both are used to quantify neutral lipids accumulation on oil droplets inside hepatocytes.

 

Tooba Haris (Other)

Principal Investigator: Dr. Mary Lauren Benton

Identifying patterns of transcription factor binding motifs in combination of enhancers

Enhancers are gene-regulatory elements that control the transcription of genes. Enhancers help with proper growth and development of cells and tissues. Mutations in these regions can cause an appearance of traits that were not previously present and likely participate in disease processes. Previous studies have shown that combination of enhancers that regulate the same gene can have redundant elements. These redundant enhancers can help reduce the effects of genetic variants on gene expression levels. We are analyzing a set of more than 70,000 human enhancer sequences in liver cells with predicted gene targets to find evidence of redundant enhancers. We are looking at the similarity of patterns of transcription factor binding motifs within enhancers with the same gene target. We created a data frame of all the motifs present in different enhancer sequences. We found the motifs MAZ to have over 2 million hits and VEFE1 and ZN467 both to have over 1.7 million hits across multiple enhancer sequences. Quantifying the similarity between different enhancer sequences will help us to better understand how enhancers cooperate to regulate genes. This can help us understand how enhancers cooperate to regulate genes and the effects of regulatory genetic variation in liver cells. 

 

Isha Thapar (Other)

Principal Investigator: Dr. Leroy Versteeg (BCM)

Evaluating the Innate Immune Response of mRNA Vaccines

To gain a deeper understanding on how mRNA molecules trigger specific innate immune receptors, we developed an in vitro transfection system to measure the innate responses triggered by mRNA constructs to: 1) identify the innate immune receptors involved in the recognition of mRNA molecules; 2) establish the timing of activation of these immune receptors; and 3) elucidate the differences in the innate immune response between primary and immortal murine cell lines. 

Our preliminary results found that the ligand 3p-hpRNA (RIG-1 ligand) is the strongest inducer of the innate immune response, making it a suitable and robust positive control to be used when testing the innate immune responses of potential mRNA vaccine candidates in vitro. Overall, we observed that transfected BMDCs react more strongly to ligands than DC2.4 and MC57G cells. Furthermore, transfected BMDCs with OVA mRNA and OVA 5moU mRNA produced higher levels of IFN-Alpha and IFN-Beta, as well as the highest fold changes measured by RT-qPCR, followed by MC57G and DC2.4 cells. Additionally, transfected MC57G fibroblasts showed a greater success of transfection with OVA mRNA and OVA 5moU mRNA compared to DC2.4 cells. Modification of OVA 5moU showed a decrease in innate immune activation in BMDCs and MC57G cells, but not in DC2.4 cells. Lastly, timepoint experiments ranging from 3 hours up to 72 hours post transfection with the 3p-hpRNA showed that innate immune responses increase after 6 hours, with the strongest responses observed 24 hours post transfection, both in DC2.4 cells and BMDCs.

 

 

Oral presentations 2: Neuroscience, Chemistry, Philosophy of Medicine: Zoom link

Moderator: Shivani A. & Joyce S.

 

Esther Ko (Neuroscience)

Principal Investigator: Dr. Lara Hwa

Role of serotonin 2C receptors in excessive voluntary drinking in mice

Studies have implicated the role of serotonin (5-HT) in mediating alcohol (EtOH) use disorders and binge-drinking. SB242084, a 5-HT2C receptor antagonist, has shown to reduce EtOH intake in adult male C57BL/6J mice.

The current study uses adult male C57BL/6J mice to investigate the effects of SB242084 on EtOH intake using an intermittent access to 20% (w/v) EtOH protocol, an animal model of long-term binge-like drinking. Mice are given 20% EtOH on alternating days of the week, 3 hours into the dark cycle, with water available ad libitum for 4 weeks. After 4 weeks of EtOH drinking, mice are given 0.3, 1.0, 3.0 mg/kg SB242084 20 minutes before drinking through intraperitoneal injections and ethanol consumption during the initial 2, 4, and 24 hours is measured in the intermittent access group, which is compared to a group of mice given continuous, every day access to 20% EtOH and water. Water drinking is also monitored as a second fluid control. The study also investigates the effects of SB242084 on anxiety-like and locomotor behavior in B6 mice through an open field test. 

After 4 weeks of intermittent access to EtOH and SB242084 injection, C57BL/6J mice had a dose-dependent reduction in EtOH consumption without reductions in water consumption. In contrast,  mice drinking on a continuous access schedule showed no significant reduction in EtOH consumption after SB242084 administration.  Mice also did not display reduced anxiety-like or locomotor behavior after SB242084 administration. 

The results suggest the therapeutic potential of SB242084 for alcohol use disorders. Observed differences in responses to SB242084 between drinking groups also imply differing neural mechanisms between excessive and moderate drinking driven by serotonin in the brain. The current study uses male mice, but future studies may benefit from investigating sex differences with the addition of female mice.

 

Sean Duval-Arnould (Neuroscience)

Principal Investigator: Dr. Lara Hwa 

Intermittent Access-induced Output of Hippocampal b-Dynorphin on Fear Learning

It is well established that limbic system is a brain region critical in fear learning and memory. It is furthermore established that the consumption of ethanol has positive effects on the output of hippocampal beta-dynorphins – a neuropeptide that is considered to be significantly correlated to limbic system long-term potentiation, implicating spatial learning and fear-forming memories. Here I, under the supervision of personal investigator Dr. Lara Hwa, will investigated the role of dynorphins in the formation and extinction of fear memories in alcohol-dependent mice. While dynorphin microinjections and ethanol consumption have separately been used as paradigms to study fear learning in mice models, the use of an intermittent access ethanol-consumption paradigm, with a focus on hippocampal dynorphin output, in studying fear memory is novel. Currently the research is in its intermediary phase with both cohorts of C57BL/6J mice, eight in the experimental intermittent-access group and eight in the control water-drinking group, currently under intermittent access consumption conditions. Fear conditioning and experimentation post a five-week ethanol consumption period through the use of a fear box apparatus, which that delivers an aversive foot shocks paired with a loud tone, will commence in three weeks’ time.

 

Maddy Brown (Chemistry)

Principal Investigator: Dr. Daniel Romo

Pharmacophore Directed Retrosynthesis Applied to Lajollamycin

Total synthesis is the completion of chemical synthesis of a complex molecule, often organic natural products, using commercially available starting materials. In the Romo Lab, retrosynthesis is used to complete total synthesis of biologically active natural products. Retrosynthesis is a strategy used to plan a total synthesis by beginning with the target molecule, then working backwards by disassembling the target molecule into simpler precursor structures, until commercially available starting materials are reached. Pharmacophore directed retrosynthesis (PDR), developed by the Romo lab, is a unique type of retrosynthesis which considers the pharmacophore, the minimal structure needed for biological activity, during retrosynthetic planning. Using this approach, the pharmacophore is synthesized first, and structure-activity relationship (SAR) information is gathered en route to the natural product from increasingly complex derivatives. PDR is most useful when applied to natural products where little is known regarding its presumed cellular targets, or structural features required for biological activity, such as the natural product lajollamycin. Lajollamycin is part of the oxazolomycin family, whose members all bear a spiro-β-lactone-γ-lactam core. In addition to the structural complexity of lajollamycin, the Romo group is also interested in lajollamycin’s range of biological activity against various cancer cell lines, HIV strains, and many drug-sensitive and drug-resistant bacteria, such as penicillin-resistant Streptococcus pneumoniae. Derivatives of lajollamycin are currently being synthesized en route to the natural product. These derivates will be assayed for biological activity to aid in identification of the pharmacophore. Furthermore, biologically active derivatives will be subject to a proteomics study to identify lajollamycin’s protein targets and contribute to knowledge about the human proteome. 

 

Andre Chavez (Philosophy of Medicine)

Principal Investigator: Andre Chavez

Constructing a Phenomenological Account of Illness: Revisiting Sartre’s Constitutional Progression

During the latter half of the twentieth century, the dominant biomedical model of health led to an acute devaluation of the lived illness experience. In response, a phenomenological model of health was proposed to resolve the problems in treating patients that arose with the biomedical model, by revaluing the experience of illness rather than physiologically objectifying disease—especially with respect to healing persons, not curing diseases, as its goal. In this paper, I articulate Sartre’s constitutional progression of illness through the triad of maladies—disease, sickness, and illness—to make it more compatible with contemporary philosophy of medicine and explore its relevance for the medical practice. To accomplish this, I discuss the Sartrean levels of pre-reflective pain; lived, bodily discomfort; suffered illness; disease pondering; and disease state, as delineated by Toombs and extended by Svenaeus. Then, I examine incongruencies between Sartre’s constitutional progression and recent philosophy of medicine. Afterward, I apply Hofmann’s revision of Twaddle’s triad to address term ambiguities that emerge in Sartre’s progression, as read with current understandings of ‘illness’ and ‘disease.’ Having made a dialectical clarification, I then discuss the scope and limitations of constructing a phenomenological account of illness. I conclude by discussing the implications of these associations for medical practice.



 

Poster Presentations

Biology, Psychology, Neuroscience, Environmental Science, & Anthropology: Zoom Link

Moderators: Tiffany L. & Ruhi T. 

 

Naya Jimenez (Biology)

Principle Investigator: Dr. Bessie Kebaara

Growth and Expression of Diverse Saccharomyces cerevisiae Wild-Type and  Nonsense-Mediated mRNA Decay Mutants on Nutritional V.S. Toxic Metals

The nonsense-mediated mRNA decay pathway (NMD) is an mRNA degradation pathway observed in most eukaryotic organisms. NMD allows for the rapid recognition and degradation of mRNAs that prematurely terminate translation. This includes mRNAs containing premature termination codons alongside natural mRNAs. Natural mRNAs, regulated by NMD, encode fully functional proteins which carry out a variety of cellular processes. One of these processes includes bio-metal homeostasis. To explore the significance of NMD regulation on bio-metal homeostasis, wildtype and NMD mutant yeast strains of diverse genetic backgrounds were grown in complete minimal media containing copper and cadmium. Although copper serves an essential physiological role as a coenzyme, excessive intracellular copper concentrations can be directly linked to cell toxicity. Additionally, although cadmium ions are known carcinogens, pollutants, and teratogens, little is known surrounding cadmium’s underlying molecular mechanisms. To further understand the roles of both heavy metal ions on the NMD pathway, the growth rates of select strains of Saccharomyces cerevisiae were analyzed as they were cultured within a variety of environmental conditions. Along with this, the changing expression rates of PCA1, an NMD-regulated gene, were also examined. It was hypothesized that yeast cell populations would adapt differently in response to the environmental presence of copper and cadmium as the functionality of the NMD-regulation process fluctuated. Through this, the effect of the presence or absence of these metal ions in relation to a functional NMD pathway was determined. It has been discovered that S. cerevisiae strains from diverse genetic backgrounds respond differentially to environmental stimuli. 

 

Grace Jang (Psychology)

Principle Investigator: Grace Jang

How Gender Attitudes Affect Preferential Hiring of Women

Benevolent sexism, beliefs that seem positive but paint women as inferior to men, has shown a relationship with the lack of challenges given to female workers (King et al., 2010). Research has shown that women more likely get what they want in a workplace when their behaviors line up with stereotypical gender roles (Cheung et al., 2015). In this study, we examined the relationship between stereotypical gender attitudes and preferential hiring of women in a nationally representative sample (N = 628). Multiple regression analyses revealed that the belief that women should work from home after their youngest is in school, as well as disagreement with the sentiment that what most women want is a home and kids predicted opposition to the preferential hiring of women. Future research with benevolent sexism can be expanded into looking how it relates to equality and diversity initiatives within the workplace.

 

Vanessa Muniz (Psychology)

Principle Investigator: Vanessa Muniz 

Feasibility of the Elkins Hypnotizability Scale- Spanish Translation

The Elkins Hypnotizability Scale (EHS) is a valid and highly reliable standardized scale that measures individual differences in hypnotizability. Given the brevity and validity of the EHS it is a gold standard of hypnotizability in clinical care and research. The EHS currently does not provide a Spanish version of the scale for Spanish-language speakers. This suggests disproportional accessibility to the EHS, leading to scarcity of clinical research and access to the EHS in clinical interventions in a more diverse population. The present study addressed this gap in the literature to make the EHS accessible to Spanish-speaking adults. This study translated the EHS to Spanish and administered it to a Spanish-speaking sample to observe its feasibility and usefulness. The participants’ hypnotizability levels were measured with the EHS and post-assessment questionnaires were used to evaluate participants’ ratings of the EHS and open-ended feedback regarding their experience. Descriptive statistics were calculated for each of the outcome measures; differences in hypnotizability levels were observed to further assess the feasibility of the Spanish scale and potential cultural variables that might influence an individual’s response to hypnosis.

 

Nick Ahmed (Neuroscience)

Principle Investigator: Dr. Lara Hwa

The Impact of Social Hierarchy Stress on Voluntary Alcohol Consumption in C57BL/6J Mice

With widespread access and higher social acceptability, Alcohol use disorder has been found to be the most common form of substance use in the United States. One prominent risk factor in alcohol use disorder is the pervasion of stress in an individual’s life. This research seeks to identify the underlying neurological mechanisms of the stress risk factor, specifically in the context of a social hierarchy, in animal models. While social hierarchies are naturally formed among group-housed mice, we utilize the tube test protocol to identify these rankings followed by a battery of behavioral tests to identify anxiety-like behaviors. These anxiety-like behaviors serve as secondary indicators of lower ranked mice. Specific assays include the open field, elevated plus maze, three-chamber social interaction test, exposure to predator odor, forced swim test, and intermittent, two-bottle choice alcohol drinking. Our hypothesis states that lower ranking mice will consume more ethanol within the intermittent access paradigm, and initial findings do uphold this assumption. Further studies will expand to female mice as they may not have the same response to social hierarchy stress paradigm thus limiting any potential effects if exposed to the intermittent access alcohol drinking protocol.

 

Maddison Vrazel (Env. Science)

Principle Investigator: Dr. Ramon Lavado

Cytotoxic Effects of Indoles on MSC (Mesenchymal stem cells)

Indoles are a form of phytochemical produced by the intestinal bacteria and are commonly found in the microbiota. At this time, its health benefits are unknown although, there is suggestion of it partaking in some gastrointestinal and liver diseases. Due to this, it is important that we screen the toxicity levels of several indoles using in vitro methods. This experiment involves the use of a cytotoxicity test on the cell line, MSC, to study 5 indole compounds: Indole-3-acidic acid, Indole-3-carboxyaldehyde, Indole-3-carboxylicic acid, Indole-3-propionic acid, and 3-Methylindole. Differentiated MSC were exposed to each concentration ranging from 100 mM to 100 pM.

Brian Adjetey (Anthropology)

Principle Investigator: Dr. Samuel Urlacher

Predictors of a biomarker of Environmental Enteric Dysfunction and its relationship to linear growth among Amazonian children

Childhood growth faltering has been linked to poor cognitive development, oral vaccine failure, and increased susceptibility to infectious and chronic diseases. In low-and middle-income countries (LMICs), recent studies suggest that Environmental Enteric Dysfunction (EED), a subclinical condition of the small intestine linked to poor sanitation, is a leading cause of poor infant growth. However, EED’s environmental predictors and its relationship to growth has never been investigated among children over the age of 5. Capitalizing on a unique dataset from 86 rural and peri-urban living Amazonian Shuar children (ages 4-12; 49% female), this study aims to define the relationships between environmental conditions, Endotoxin Core Antibodies (EndoCAb, a biomarker of EED measured in finger-prick dried blood spots), and linear growth among school-age children. As predicted, children from households with lower incomes and less modernized homes had greater EndoCAb levels (both p< 0.05). When more specific household variables were examined, dirt floors were strongly associated with elevated EED levels (p= 0.017). Surprisingly, urban-living children had higher mean EndoCAb than their rural counterparts (p= 0.010), potentially indicating greater overall pathogen exposure among urban children, due to greater population density. Sample-wide, 24% of participants were classified as growth stunted using international standards. While EndoCAb did not directly predict stunting or children’s height-for-age, there appear to be complex relationships linking EndoCAb and child growth. Our findings point to the importance of understanding gut function for understanding child development and health in LMICs.