Louisiana Research Day Program Book 2025

Biomedical Research: Section 1

Biomedical Research: Section 1

Christine Palma, BS, OMS-II 1 ; Lydia Ta, BS, OMS-II 1 ; Nicholas Wong, BS, OMS-II 1 ; Lin Kang, PhD 1 ; K. Adam Morrow, PhD 1 ; Melissa EH Lipsmeyer MS, PhD 1 1 VCOM-Louisiana 4 EXPLORING THE PROTECTIVE ROLE OF INDOLE-3-PROPIONIC ACID IN OBESITY-DRIVEN BREAST CANCER: INSIGHTS FROM AN IN VITRO MODEL

Codi Vernace, BS, OMS-III 1 ; Sabeen Wazir, BS, OMS-II 1 ; Douglas Le, BS, MS, OMS-II 1 ; Kasia Michalak, BS MS 1 ; Lin Kang, PhD 1 ; Stephen DiGiuseppe, PhD 1 ; Melissa EH Lipsmeyer, ME, PhD 1 1 VCOM-Louisiana 5 DYSREGULATION OF ADIPOCYTE FUNCTION DURING CORONAVIRUS INFECTION

Background: Breast cancer is the second leading cause of cancer death in the U.S. with a variety of genetic and physiological contributors to its development. Obesity is associated both with a higher risk of breast cancer development, and with worse disease outcomes through several mechanisms including chronic inflammation, insulin resistance, and increased production of estrogen from adipocytes, all of which enhance cell proliferation. Furthermore, obesity-related metabolic changes can influence the composition of the gut microbiome, leading to dysbiosis, which may further affect breast cancer risk and outcomes by exacerbating inflammation, altering the hormonal milieu or through secretion of bacterial-derived metabolites that directly impact breast cancer cell function. Indole-3-propionic acid (IPA) is a gut-microbiome derived metabolite with anti inflammatory, anti-oxidative stress and glucose regulatory properties that is reduced in patients with overweight/obesity and has been shown to have cytostatic properties against breast cancer cells. However, precise mechanisms by which IPA elicits these functions, especially in the context of obesity, remain unknown.

Hypothesis: The goal of this study was to determine if IPA could alter obesity-induced changes of a hormone receptor positive (ESR, PGR and HER2) breast cancer cell line, MCF-7, in an in vitro model of obesity. Methods: For these studies, an in vitro model of obesity was utilized where breast cancer cells are cultured in media conditioned by mature human adipocytes (ACM) to mimic an obesogenic environment. MCF-7 cells were treated with either control, vehicle, ACM, IPA (1uM) or ACM+IPA media for 72 hours. Next Generation RNAsequencing analysis was used to identify novel gene pathways altered by ACM and if IPA could reverse these changes. Genes with a significant p-value (<0.05) and a log-fold greater than 2 or less than 0.5 were selected and analyzed in a public bioinformatic tool. Results: Pathway enrichment of significantly altered genes revealed that ACM induced changes in gene networks related to estrogen and insulin signaling as well as cellular tight junctions and focal adhesions. Addition of IPA to ACM treated cells resulted in reduction of insulin-signaling pathways as well as

progesterone and estrogen receptor mediated signaling. Experiments to confirm these changes via QPCR and western blot analysis are ongoing. Conclusion: Based on the preliminary RNAsequencing analysis, ACM induced gene expression changes in MCF7 cells that enhance cell survival or proliferation, and IPA may be able to mitigate these effects. Further validation and characterization of the function of IPA in breast cancer cells is needed to determine its potential therapeutic potential in the context of obesity and provide a mechanism by which balance of the gut-microbiome offers a protective role against the disease.

Context: SARS-CoV-2, the causative virus for the COVID-19 pandemic, is estimated to have caused almost 7 million deaths worldwide according to the World Health Organization. Many COVID-19 patients have other comorbidities such as obesity or diabetes mellitus and are at higher risk of complications and mortality. Reports have shown that these patients develop uncontrolled hyperglycemia that exacerbate the development of severe COVID-19 partly due to inflammation and insulin resistance. Emerging studies have demonstrated that dysfunctional adipose tissue due to SARS-CoV-2 infection likely contributes to the development of hyperglycemia in these patients. However, the precise molecular mechanisms behind the pathological changes in adipose tissue due to viral infection remains elusive. Objective: This study aims to investigate the molecular mechanisms by which adipocytes alter their physiology and insulin signaling in response to coronavirus infection. Methods: As a safe model of SARS-CoV2 infection, we utilized human coronavirus OC43 (HCoV-OC43) to infect mature adipocytes that

had been differentiated from subcutaneous fibroblast stem cells. Adipocytes were infected with HCoV-OC43 for 72 hours, after which samples were collected for RNA sequencing, quantitative PCR (qPCR) and western blot. analyses. Results: Human adipocytes were successfully infected with HCoV-OC43 after 72 hours as evidenced by the presence of OC43 nucleocapsid and spike proteins by western blot analysis. Further western blot analysis determined that OC43 infection significantly altered expression of genes essential for adipocyte function. Ongoing RNA sequencing analysis aims to provide a comprehensive overview of the physiological pathways disrupted by HCoV-OC43 infection. Conclusions: Our findings demonstrate that the human coronavirus HCoV-OC43 can effectively infect differentiated adipocytes and significantly alter genes related to adipocyte function. These alterations not only suggest a proposed mechanism through which SARS-CoV2 may impact metabolic health but may give reason to the potential exacerbations seen in patients with pre-existing comorbidities such as obesity.

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2025 Research Recognition Day