Louisiana Via Research Day Book 2026

Biomedical Research: Section 1

Biomedical Research: Section 1

Taylor Raff, OMS-II; Roya Noorbakhsh, OMS-II; Kayla Griffith, OMS-II, Rose Pwint, OMS-II; Hannah Khairandish, OMS-II; Francheska Brzazgon, OMS-II; Kasia Michalak, MSc; Zakaria Abd Elmageed, PhD; Hassan Ebrahim, PhD VCOM-Louisiana 4 THE NATURAL DITERPENE INCENSOLE ACETATE INTERFERES WITH ONCOGENIC C-MET ACTIVATION IN BREAST CANCER CELLS

Erin Knight, OMS-III 1 ; Krishna Patel; Sophia R. Voth; Chung-Sik Choi, PhD 2 ; Mike T. Lin 2 , PhD; Troy Stevens, PhD 2 ; Melissa Lipsmeyer PhD 1 ; Rebekah Morrow PhD 3 ; K. Adam Morrow PhD 1* ’ and Sarah Voth PhD 1 *Indicates equal contributions 1 Cell Biology and Physiology, VCOM-Louisiana 2 Physiology and Cell Biology, University of South Alabama College of Medicine 3 Microbiology and Immunology, VCOM-Louisiana 3 CYSTATIN C ATTENUATES TRANSMISSIBLE TAU CYTOTOXICITY IN ACUTE LUNG INFECTION

Rationale: Pseudomonas aeruginosa is a common agent of pneumonia induced acute respiratory distress syndrome (ARDS). Virulent respiratory strains of P. aeruginosa utilize a type III secretion system (T3SS) to inject toxins directly into host cells. The T3SS toxin exoenzyme Y (ExoY) is a soluble nucleotidyl cyclase expressed by 90% of clinical strains. ExoY generates unregulated production of cytosolic cyclic nucleotides that induce the hyperphosphorylation of microtubule stabilizing tau. Hyperphosphorylated tau falls from the microtubules promoting cytoskeletal collapse, increased permeability, and the aggregation and release of hyperphosphorylated tau cytotoxins into the extracellular space. Oligomeric tau propagates damage from cell-to-cell and can be passed infectiously from one species to another as a toxic prion. ExoY-elicited tau is often found complexed with lung endothelial-derived amyloid-beta (Aß) converting it into a transmissible cytotoxins as well. Cystatin C (CysC), a ubiquitous cysteine protease that modulates Aß homeostasis, autophagy, and innate defense, is often precipitated with Aß-tau complexes. In these studies, we sought to determine whether

repletion of proteolytically active CysC during ExoY-competent infection would reduce the virulence of ExoY-generated transmissible cytotoxins. Methods: Established rat secondary pulmonary microvascular endothelial cells (PMVECs) were treated with either vehicle control or recombinant active CysC over a range of concentrations (50 ng/ml, 100 ng/ ml, 150 ng/ml) both with and without infection. Confluent monolayers were infected with either the isogenic control strain (ExoYK81M; no cyclase activity) to the virulent ExoY+ lab strain (injects ExoY only) or the ExoY-competent clinical isolate PA808 at a multiplicity of infection of 201 in HBSS. Cell Supernatants, whole cell lysates, and RNA were collected at ~ 5 h post-infection. Supernatants were filter sterilized. Supernatants and lysates were immunoblotted for tau, Aß, CysC, and autophagy proteins SQSTM1 and LC3-I and LC3-II. RT-qPCR was used to assess transcript for each protein. Filter-sterilized supernatants were boiled for 15 min and then iced for 15 min to inactivate non-amyloid proteins prior to transfer to naïve monolayers. Lactate

dehydrogenase (LDH) assays and resazurin assays were utilized to assess cytotoxicity and redox homeostasis, respectively. Results: Treatment of uninfected PMVECs with CysC was not cytotoxic or disruptive to redox homeostasis at any concentration. CysC repletion increased innate immune transcripts and promoted autophagic flux. Treatment of infected PMVECs at even the lowest dose of CysC reduced the release of pathologic tau by 4-fold as compared to untreated cells intoxicated with ExoY. Treatment with 50 ng/ml of CysC during ExoY-competent infection had the most significant impact in reducing amyloid mediated transmissible injury (p < 0.018), while treatment with 100 ng/ml CysC was only slightly less effective (p < 0.0190), and treatment with 150 ng/ml CysC did not significantly reduce transmissible cytotoxicity as compared to untreated ExoY intoxicated cells. Conclusions: Repletion of proteolytically active CysC during ExoY-competent infection is cytoprotective and suppresses the virulence of transmissible cytotoxicity.

Context: Frankincense, also known as olibanum, is an aromatic resin used in

overexpressed in TNBC and is associated with tumor aggressiveness, invasion and metastasis, chemotherapy resistance. Objective and/or Hypothesis: As a part of an ongoing project to discover novel c-Met modulators, we explored the anti-breast cancer potential IA against TNBC cells. Methods: MTT assay was used to evaluate the proliferation of cancerous cells, while scratch assay was used to monitor cell migration. Western blot was used to uncover the potential molecular target mediating the anticancer effect of IA. Results: IA effectively suppressed the proliferation, migration, invasion, and colonization of TNBC cells at low µM concentrations. Furthermore, IA effectively suppressed the phosphorylation (activation) of c-Met in a dose-dependent manner, as demonstrated by Western blot. Furthermore, molecular modeling studies suggested in-pocket binding conformation of IA which is energetically stabilized by interactions with amino acids at the hinge region of the kinase domain. Our ongoing

research focuses on exploring the effect of IA on the downstream signaling pathways of c-Met.

incense and perfume for spiritual, religious, and meditative purposes. Recent research have shown its utility for the management of inflammation, pain, arthritis and cancer. Incensole acetate (IA) is the main diterpene found in olibanum and can be purified using chromatographic techniques. Breast cancer (BC) is the most diagnosed cancer in women and the second leading cause of cancer death, after lung cancer. Recent statistics estimate that 316,950 women will be diagnosed with invasive BC and 42,170 women will die in 2025. BC is a highly heterogenous disease, characterized by a wide range of subtypes that vary in their biological features, clinical presentation, and response to treatment. Subtypes like hormone receptor-positive, HER2-positive, and triple negative breast cancer (TNBC) exhibit distinct patterns of growth, metastasis, and resistance to therapies. TNBC is the most aggressive subtype with highest potential for metastasis and recurrence. Chemotherapy remains the mainstay therapeutic modality for TNBC, as hormone and HER-2 targeted therapies are ineffective. C-Met is a receptor tyrosine kinase that is

Conclusions: IA is a novel c-Met modulator diterpene amenable for further development as a lead compound for the control of aggressive c-Met-addicted TNBC.

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2026 Research Recognition Day