Selected Grantee Publications
Proinflammatory Cytokines Suppress Stemness-Related Properties and Expression of Tight Junction in Canine Intestinal Organoids
Nakazawa et al., In Vitro Cellular & Developmental Biology—Animal. 2024.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11419940
Cells in the gastrointestinal tract are exposed to numerous stressors that can promote excessive inflammation, including environmental chemicals and dietary substances. Researchers studied how canine intestinal epithelial cell (IEC)–derived organoids responded to exposure to one of three proinflammatory cytokines; interferon-γ (IFN-γ), tumor necrosis factor-α (TNFα), or interleukin-1β (IL1β). Exposure to IFN-γ resulted in downregulation of the stem cell marker Lgr5. Only IFN-γ exposure resulted in increased production of caspase 3 and caspase 8. Exposure to either IFN-γ or IL1β resulted in suppressed cell proliferation. The pro-inflammatory cytokines caused reduced tight junction protein expression and compromised membrane integrity. These findings are important to understanding IEC response to different inflammatory stimuli and to broadening knowledge of gut physiology. Supported by ORIP (K01OD030515, R21OD031903).
The Splicing Factor hnRNPL Demonstrates Conserved Myocardial Regulation Across Species and Is Altered in Heart Failure
Draper et al., FEBS Letters. 2024.
https://pubmed.ncbi.nlm.nih.gov/39300280/
The 5-year mortality rate of heart failure (HF) is approximately 50%. Gene splicing, induced by splice factors, is a post-transcriptional modification of mRNA that may regulate pathological remodeling in HF. Researchers investigated the role of the splice factor heterogenous nuclear ribonucleoprotein-L (hnRNPL) in cardiomyopathy. hnRNPL protein expression is significantly increased in a male C57BL/6 transaortic constriction–induced HF mouse model and in clinical samples derived from canine or human HF patients. Cardiac-restricted knockdown of the hnRNPL homolog in Drosophila revealed systolic dysfunction and reduced life span. This study demonstrates a conserved cross-species role of hnRNPL in regulating heart function. Supported by ORIP (K01OD028205) and NHLBI.
Identifying Mitigating Strategies for Endothelial Cell Dysfunction and Hypertension in Response to VEGF Receptor Inhibitors
Camarda et al., Clinical Science. 2024.
https://pubmed.ncbi.nlm.nih.gov/39282930/
Vascular endothelial growth factor receptor inhibitor (VEGFRi) use can improve survival in patients with advanced solid tumors, but outcomes can worsen because of VEGFRi-induced hypertension, which can increase the risk of cardiovascular mortality. The underlying pathological mechanism is attributed to endothelial cell (EC) dysfunction. The researchers performed phosphoproteomic profiling on human ECs and identified α-adrenergic blockers, specifically doxazosin, as candidates to oppose the VEGFRi proteomic signature and inhibit EC dysfunction. In vitro testing of doxazosin with mouse, canine, and human aortic ECs demonstrated EC-protective effects. In a male C57BL/6J mouse model with VEGFRi-induced hypertension, it was demonstrated that doxazosin prevents EC dysfunction without decreasing blood pressure. In canine cancer patients, both doxazosin and lisinopril improve VEGFRi-induced hypertension. This study demonstrates the use of phosphoproteomic screening to identify EC-protective agents to mitigate cardio-oncology side effects. Supported by ORIP (K01OD028205), NCI, NHGRI, and NIGMS.
Large Animal Models Enhance the Study of Crypt-Mediated Epithelial Recovery From Prolonged Intestinal Ischemia Reperfusion Injury
McKinney-Aguirre et al., American Journal of Physiology-Gastrointestinal and Liver Physiology. 2024.
https://pubmed.ncbi.nlm.nih.gov/39404771/
Intestinal ischemia and reperfusion injury (IRI) is a severe pathological alteration that compromises the intestinal epithelial barrier, causing bacterial translocation, shock, sepsis, and potentially death. Preclinical research for IRI has focused on utilizing murine models, but mice demonstrate key anatomical and physiological intestinal differences from humans, such as tissue enzymes, intestinal permeability, and hypoxic response pathways. The researchers compared a 3-hour IRI porcine model to a 3-hour IRI murine model to reveal which demonstrated a stronger translational capacity. Both models demonstrated crypt damage, but only the porcine model showed recovery-associated crypt death expansion and re-epithelialization. At 72 hours post-IRI, mouse mortality was 84.6%, whereas porcine mortality was 0%. A porcine model would be more reliable for future translational studies focused on understanding IRI mechanisms for diagnosis and therapy advancements. Supported by ORIP (T32OD011130, K01OD010199, R03OD026598) and NIDDK.
Enterohemorrhagic Escherichia coli (EHEC) Disrupts Intestinal Barrier Integrity in Translational Canine Stem Cell-Derived Monolayers
Nagao et al., Microbiology Spectrum. 2024.
https://pubmed.ncbi.nlm.nih.gov/39162490/
EHEC produces Shiga toxin, which causes acute colitis with symptoms such as hemolytic uremic syndrome and bloody diarrhea. The researchers developed a colonoid-derived monolayer model to understand EHEC’s impact on canine gut health. Colonoid-derived monolayers co-cultured with EHEC demonstrated key differences compared with the control and nonpathogenic E. coli co-cultures. Scanning electron microscopy displayed EHEC aggregated and attached to the microvilli. EHEC-infected monolayers demonstrated significantly weakened membrane integrity and increased inflammatory cytokine production, specifically TNFα. The researchers developed a novel in vitro model that offers an additional platform for understanding the mechanisms of EHEC pathogenicity, developing therapeutics for EHEC, and studying additional enteric pathogens. Supported by ORIP (K01OD030515, R21OD031903).
Acquired Dysfunction of CFTR Underlies Cystic Fibrosis-Like Disease of the Canine Gallbladder
Gookin et al., American Journal of Physiology-Gastrointestinal and Liver Physiology. 2024.
https://pubmed.ncbi.nlm.nih.gov/39041675/
Mucocele formation in dogs is pathologically similar to cystic fibrosis. In this study, researchers investigated the role of cystic fibrosis transmembrane conductance regulator (CFTR) in the pathogenesis of the disease. They determined the location and frequency of disease-associated variants in the coding region of CFTR using whole-genome sequence data from 2,642 dogs representing breeds at low risk, high risk, or with confirmed disease. The authors’ findings establish significant loss of CFTR-dependent anion secretion by mucocele gallbladder mucosa. There were no significant differences in CFTR gene variant frequency, type, or predicted impact comparing low-risk, high-risk, and definitively diagnosed groups of dogs. Their results suggest a disease of the canine gallbladder that is similar to cystic fibrosis and is driven by CFTR dysfunction. Supported by ORIP (T35OD011070, K01OD027058).