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.
De Novo and Inherited Variants in DDX39B Cause a Novel Neurodevelopmental Syndrome
Booth et al., Brain. 2025.
https://academic.oup.com/brain/advance-article/doi/10.1093/brain/awaf035/8004980?login=true
DDX39B is a core component of the TRanscription-EXport (TREX) super protein complex. Recent studies have highlighted the important role of TREX subunits in neurodevelopmental disorders. Researchers describe a cohort of six individuals (male and female) from five families with disease-causing de novo missense variants or inherited splice-altering variants in DDX39B. Three individuals in the cohort are affected by mild to severe developmental delay, hypotonia, history of epilepsy or seizure, short stature, skeletal abnormalities, variable dysmorphic features, and microcephaly. Using a combination of patient genomic and transcriptomic data, in silico modeling, in vitro assays, and in vivo Drosophila and zebrafish models, this study implicates disruption of DDX39B in a novel neurodevelopmental disorder called TREX-complex-related neurodevelopmental syndrome. Supported by ORIP (U54OD030165).
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.
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.
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.
Multimodal Analysis of Dysregulated Heme Metabolism, Hypoxic Signaling, and Stress Erythropoiesis in Down Syndrome
Donovan et al., Cell Reports. 2024.
https://pubmed.ncbi.nlm.nih.gov/39120971
Down syndrome (DS), a genetic condition caused by the presence of an extra copy of chromosome 21, is characterized by intellectual and developmental disability. Infants with DS often suffer from low oxygen saturation, and DS is associated with obstructive sleep apnea. Investigators assessed the role that hypoxia plays in driving health conditions that are comorbid with DS. A multiomic analysis showed that people with DS exhibit elevated heme metabolism and activated stress erythropoiesis, which are indicators of chronic hypoxia; these results were recapitulated in a mouse model for DS. This study identified hypoxia as a possible mechanism underlying several conditions that co-occur with DS, including congenital heart defects, seizure disorders, autoimmune disorders, several leukemias, and Alzheimer's disease. Supported by ORIP (R24OD035579), NCATS, NCI, and NIAID.