Selected Grantee Publications
Senescent-like Microglia Limit Remyelination Through the Senescence Associated Secretory Phenotype
Gross et al., Nature Communications. 2025.
https://www.nature.com/articles/s41467-025-57632-w
Multiple sclerosis (MS) is a chronic, immune-mediated demyelinating disease in which immune cells infiltrate the central nervous system and promote deterioration of myelin and neurodegeneration. The capacity to regenerate myelin in the central nervous system diminishes with age. In this study, researchers used 2- to 3-month-old (young), 12-month-old (middle-aged), and 18- to 22-month-old (aged) C57BL/6 male and female mice. Results showed an upregulation of the senescence marker P16ink4a (P16) in microglial and macrophage cells within demyelinated lesions. Notably, treatment of senescent cells using genetic and pharmacological senolytic methods leads to enhanced remyelination in young and middle-aged mice but fails to improve remyelination in aged mice. These results suggest that therapeutic targeting of senescence-associated secretory phenotype components may improve remyelination in aging and MS. Supported by ORIP (R24OD036199), NIA, NINDS, and NIMH.
Differentiation Success of Reprogrammed Cells Is Heterogeneous In Vivo and Modulated by Somatic Cell Identity Memory
Zikmund et al., Stem Cell Reports. 2025.
https://pubmed.ncbi.nlm.nih.gov/40086446
Nuclear reprogramming can change cellular fates, yet reprogramming efficiency is low, and the resulting cell types are often not functional. Researchers used nuclear transfer to Xenopus eggs to follow single cells during reprogramming in vivo. Results showed that the differentiation success of reprogrammed cells varies across cell types and depends on the expression of genes specific to the previous cellular identity. Subsets of reprogramming-resistant cells fail to form functional cell types and undergo cell death or disrupt normal body patterning. Reducing expression levels of genes specific to the cell type of origin leads to better reprogramming and improved differentiation trajectories. This study demonstrates that failing to reprogram in vivo is cell type specific and emphasizes the necessity of minimizing aberrant transcripts of the previous somatic identity for improving reprogramming. Supported by ORIP (R24OD031956).
A New Drosophila melanogaster Research Resource: CRISPR-Induced Mutations for Clonal Analysis of Fourth Chromosome Genes
Weasner et al., G3 (Bethesda). 2025.
https://pubmed.ncbi.nlm.nih.gov/39804955
The fruit fly, Drosophila melanogaster, shares approximately 60% of its genes with human homologs and is an excellent model organism for studying mechanisms underlying human health and disease. However, the fourth chromosome of this organism is challenging to study because of the lack of genetic resources. This study presents a new resource—the Fourth Chromosome Resource Project—for studying the fourth chromosome of the fruit fly and expanding the understanding of gene function and disease mechanisms. Using gene editing approaches, researchers generated and characterized 119 mutations in 62 fourth chromosome genes, including 84 predicted null alleles and 29 in-frame deletions. Phenotypic assessments included tests for lethality, sterility, and visible traits. Many stable mutant stocks were submitted into public repositories in the United States and Japan for research purposes. Supported by ORIP (P40OD018537, R24OD028242) and NHGRI.
Suppressing APOE4-Induced Neural Pathologies by Targeting the VHL-HIF Axis
Jiang et al., PNAS. 2025.
https://pubmed.ncbi.nlm.nih.gov/39874294
The ε4 variant of human apolipoprotein E (APOE4) is a major genetic risk factor for Alzheimer’s disease and increases mortality and neurodegeneration. Using Caenorhabditis elegans and male APOE-expressing mice, researchers determined that the Von Hippel-Lindau 1 (VHL-1) protein is a key modulator of APOE4-induced neural pathologies. This study demonstrated protective effects of the VHL-1 protein; the loss of this protein reduced APOE4-associated neuronal and behavioral damage by stabilizing hypoxia-inducible factor 1 (HIF-1), a transcription factor that protects against cellular stress and injury. Genetic VHL-1 inhibition also mitigated cerebral vascular injury and synaptic damage in APOE4-expressing mice. These findings suggest that targeting the VHL–HIF axis in nonproliferative tissues could reduce APOE4-driven mortality and neurodegeneration. Supported by ORIP (R24OD010943, R21OD032463, P40OD010440), NHGRI, NIA, and NIGMS.
A Collection of Split-Gal4 Drivers Targeting Conserved Signaling Ligands in Drosophila
Ewen-Campen et al., G3 (Bethesda). 2025.
https://pubmed.ncbi.nlm.nih.gov/39569452
A modest number of highly conserved signaling pathways are known to generate a broad range of responses in multicellular animals, including mammals. How this remarkable feat is achieved is not well understood. Investigators developed and characterized a collection of genetic resources, called knock-in split-Gal4 lines, that target ligands from highly conserved signaling pathways in development and biological processes, including Notch, Hedgehog, fibroblast growth factor, epidermal growth factor, and transforming growth factor β. These Drosophila lines are useful in identifying tissues that co-express ligands of interest, genetically manipulating specific cell populations, and elucidating potential crosstalk among different conserved pathways. These resources are highly valuable for studying conserved intercellular signaling pathways relevant to human health and disease. Supported by ORIP (R24OD026435, R24OD031952, P40OD018537) and NIGMS.
Systematic Ocular Phenotyping of 8,707 Knockout Mouse Lines Identifies Genes Associated With Abnormal Corneal Phenotypes
Vo et al., BMC Genomics. 2025.
https://pubmed.ncbi.nlm.nih.gov/39833678
Corneal dysmorphologies (CDs) are a group of acquired but predominantly genetically inherited eye disorders that cause progressive vision loss and can be associated with systemic abnormalities. This study aimed to identify candidate CD genes in humans by looking at knockout mice with targeted deletions of orthologous genes that exhibited statistically significant corneal abnormalities. Analysis of data from 8,707 knockout mouse lines identified 213 candidate CD genes; 176 (83%) genes have not been implicated previously in CD. Bioinformatic analyses implicated candidate genes in several signaling pathways (e.g., integrin signaling pathway, cytoskeletal regulation by Rho GTPase, FAS signaling pathway), which are potential therapeutic targets. Supported by ORIP (U42OD011175, R03OD032622, UM1OD023221), NEI, and NHGRI.
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.
Preclinical Use of a Clinically-Relevant scAAV9/SUMF1 Vector for the Treatment of Multiple Sulfatase Deficiency
Presa et al., Communications Medicine. 2025.
https://pubmed.ncbi.nlm.nih.gov/39870870
This study evaluates a gene therapy strategy using an adeno-associated virus (AAV)/SUMF1 vector to treat multiple sulfatase deficiency (MSD), a rare and fatal lysosomal storage disorder caused by mutations in the SUMF1 gene. Researchers delivered the functional gene to male and female Sumf1 knockout mice either neonatally or after symptom onset. Neonatal treatment via cerebral spinal fluid extended survival up to 1 year, alleviated MSD symptoms, and restored normal behavior and cardiac and visual function without toxicity. Treated tissues showed widespread SUMF1 expression and enzymatic activity. These findings support the translational potential of this gene replacement therapy for clinical use in MSD patients. Supported by ORIP (U42OD010921, U54OD020351, U54OD030187) and NCI.
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.