Selected Grantee Publications
Establishing the Hybrid Rat Diversity Program: A Resource for Dissecting Complex Traits
Dwinell et al., Mammalian Genome. 2025.
https://pubmed.ncbi.nlm.nih.gov/39907792
Rat models have been extensively used for studying human complex disease mechanisms, behavioral phenotypes, and environmental factors and for discovering and developing drugs. Systems genetics approaches have been used to study the effects of both genetic variation and environmental factors. This approach recognizes the complexity of common disorders and uses intermediate phenotypes to find relationships between genetic variation and clinical traits. This article describes the Hybrid Rat Diversity Program (HDRP) at the Medical College of Wisconsin, which involves 96 inbred rat strains and aims to provide a renewable and reusable resource in terms of the HRDP panel of inbred rat strains, the genomic data derived from the HRDP strains, and banked resources available for additional studies. Supported by ORIP (R24OD024617) and NHLBI.
A Comprehensive Atlas of AAV Tropism in the Mouse
Walkey et al., Molecular Therapy. 2025.
https://pubmed.ncbi.nlm.nih.gov/39863928
Over the past three decades, adeno-associated viruses (AAVs) have emerged as the leading viral vector for in vivo gene therapy. This study presents a comprehensive atlas of AAV tropism in male and female mice, evaluating 10 naturally occurring AAV serotypes across 22 tissues using systemic delivery. Researchers employed a fluorescent protein activation approach to visualize AAV transduction patterns and detected transduction of unexpected tissues, including in adrenal glands, testes, and ovaries. Biodistribution closely matched the fluorescent signal intensity. This publicly available data set provides valuable insights into AAV vector targeting and supports optimal serotype selection for basic research and preclinical gene therapy applications in murine models. Supported by ORIP (U42OD026645, U42OD035581, U42OD026635), NCI, NHLBI, NICHD, and NIDDK.
In Vivo Expansion of Gene-Targeted Hepatocytes Through Transient Inhibition of an Essential Gene
De Giorgi et al., Science Translational Medicine. 2025.
https://pubmed.ncbi.nlm.nih.gov/39937884
This study explores Repair Drive, a platform technology that selectively expands homology-directed repair for treating liver diseases in male and female mice. Through transient conditioning of the liver by knocking down an essential gene—fumarylacetoacetate hydrolase—and delivering an untraceable version of that essential gene with a therapeutic transgene, Repair Drive significantly increases the percentage of gene-targeted hepatocytes (liver cells) up to 25% without inducing toxicity or tumorigenesis after a 1-year follow-up. This also resulted in a fivefold increase in expression of human factor IX, a therapeutic transgene. Repair Drive offers a promising platform for precise, safe, and durable correction of liver-related genetic disorders and may expand the applicability of somatic cell genome editing in a broad range of liver diseases in humans. Supported by ORIP (U42OD035581, U42OD026645), NCI, NHLBI, and NIDDK.
Peripherally Mediated Opioid Combination Therapy in Mouse and Pig
Peterson et al., The Journal of Pain. 2025.
https://pubmed.ncbi.nlm.nih.gov/39542192
This study evaluates novel opioid combinations for pain relief with reduced side effects. Researchers investigated loperamide (a μ-opioid agonist) with either oxymorphindole or N‑benzyl-oxymorphindole—both δ-opioid receptor partial agonists—in mice (male and female) and pigs (male). These combinations produced synergistic analgesia across species without causing adverse effects or respiratory depression. The therapies significantly reduced hypersensitivity in post-injury models, outperforming morphine alone. These findings suggest that peripherally acting opioid combinations can offer effective, safer alternatives for pain management, potentially lowering opioid misuse and side effects. This approach could improve clinical strategies for treating chronic and acute pain with limited central opioid exposure. Supported by ORIP (T32OD010993), NHLBI, and NIDA.
Failure of Colonization Following Gut Microbiota Transfer Exacerbates DSS-Induced Colitis
Gustafson et al., Gut Microbes. 2025.
https://pubmed.ncbi.nlm.nih.gov/39812347/
Microorganisms that inhabit the gastrointestinal tract, known as the gut microbiome (GM), play a vital role in health and disease. Dysbiosis, the reduced richness of symbiotic commensals in the GM, exacerbates inflammation and increases inflammatory bowel disease (IBD) severity. Researchers used a mouse model for IBD to determine the role of GM composition, richness, and transfer methods on IBD disease severity. A comparison of GM transfer methods demonstrated that co-housing was not as efficient as embryonic transfer and cross-fostering. The GM of the donor and recipient during co-housing determined transfer efficiency. Transfer of a low richness GM to a recipient with high GM richness, followed by dextran sodium sulfate administration to induce IBD, resulted in significant weight loss, greater lesion severity, increased inflammatory response, and higher mortality rates. This study provides evidence regarding the role of GM composition and colonization in IBD modulation. Supported by ORIP (T32OD011126, U42OD010918) and NIGMS.
Spatiotemporal Characterization of Cyclooxygenase Pathway Enzymes During Vertebrate Embryonic Development
Leathers et al., Developmental Biology. 2025.
https://pubmed.ncbi.nlm.nih.gov/39581452/
The cyclooxygenase (COX) pathway plays a fundamental role in embryonic development. Disruptions of the COX pathway during pregnancy cause developmental anomalies, including craniofacial clefts, impaired gut innervation, and neural tube defects in the embryo. Researchers used Gallus gallus embryos to study the expression of COX pathway enzymes during neurulation. COX-1 protein expression was upregulated in cells undergoing mitosis, whereas COX-2 protein expression was ubiquitous. This study provides spatiotemporal expression data of COX pathway enzymes at key embryonic development stages in G. gallus and guides future studies focused on defining the role of these enzymes during embryonic development. Supported by ORIP (T35OD010956), NEI, NIDCR, and NIGMS.
Plural Molecular and Cellular Mechanisms of Pore Domain KCNQ2 Encephalopathy
Abreo et al., eLife. 2025.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11703504
This study investigates the cellular and molecular mechanisms underlying KCNQ2 encephalopathy, a severe type of early-onset epilepsy caused by mutations in the KCNQ2 gene. Researchers describe a case study of a child with a specific KCNQ2 gene mutation, G256W, and found that it disrupts normal brain activity, leading to seizures and developmental impairments. Male and female Kcnq2G256W/+ mice have reduced KCNQ2 protein levels, epilepsy, brain hyperactivity, and premature deaths. As seen in the patient study, ezogabine treatment rescued seizures in mice, suggesting a potential treatment avenue. These findings provide important insights into KCNQ2-related epilepsy and highlight possible therapeutic strategies. Supported by ORIP (U54OD020351, S10OD026804, U54OD030187), NCI, NHLBI, NICHD, NIGMS, NIMH, and NINDS.