Selected Grantee Publications
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.
Single-Cell Transcriptomics Predict Novel Potential Regulators of Acute Epithelial Restitution in the Ischemia-Injured Intestine
Rose et al., American Journal of Physiology-Gastrointestinal and Liver Physiology. 2025.
https://pubmed.ncbi.nlm.nih.gov/39853303
Following ischemia in the small intestine, early barrier restoration relies on epithelial restitution to reseal the physical barrier and prevent sepsis. Pigs share a similar gastrointestinal anatomy, physiology, and microbiota with humans. Researchers used neonatal and juvenile, 2- to 6-week-old male and female Yorkshire cross pigs to determine upstream regulators of restitution. Single-cell sequencing of ischemia-injured epithelial cells demonstrated two sub-phenotypes of absorptive enterocytes, with one subset presenting a restitution phenotype. Colony-stimulating factor-1 (CSF1) was the only predicted upstream regulator expressed in juvenile jejunum compared with neonatal jejunum. An in vitro scratch wound assay using IPEC-J2 cells showed that BLZ945, a colony-stimulating factor 1 receptor antagonist, inhibited restitution. Ex vivo ischemia-injured neonatal pig jejunum treated with exogenous CSF1 displayed increased barrier function. This study could inform future research focused on developing novel therapeutics for intestinal barrier injury in patients. Supported by ORIP (T32OD011130, K01OD028207), NCATS, NICHD, and NIDDK.
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.
Transcriptomic Analysis of Skeletal Muscle Regeneration Across Mouse Lifespan Identifies Altered Stem Cell States
Walter et al., Nature Aging. 2024.
https://pubmed.ncbi.nlm.nih.gov/39578558
Age-related skeletal muscle regeneration dysfunction is poorly understood. Using single-cell transcriptomics and high-resolution spatial transcriptomics, researchers evaluated factors contributing to age-related decline in skeletal muscle regeneration after injury in young, old, and geriatric male and female mice (5, 20, and 26 months old). Eight immune cell types were identified and associated with age-related dynamics and distinct muscle stem cell states specific to old and geriatric tissue. The findings emphasize the role of extrinsic and intrinsic factors, including cellular senescence, in disrupting muscle repair. This study provides a spatial and molecular framework for understanding regenerative decline and cellular heterogeneity in aging skeletal muscle. Supported by ORIP (F30OD032097), NIA, NIAID, NIAMS, NICHD, and NIDA.
Placental Gene Therapy in Nonhuman Primates: A Pilot Study of Maternal, Placental, and Fetal Response to Non-Viral, Polymeric Nanoparticle Delivery of IGF1
Wilson et al., Molecular Human Reproduction. 2024.
https://academic.oup.com/molehr/article/30/11/gaae038/7876288#493719584
This study investigates a novel nanoparticle-mediated gene therapy approach for addressing fetal growth restriction (FGR) in pregnant female nonhuman primates. Using polymer-based nanoparticles delivering a human insulin-like growth factor 1 (IGF1) transgene, the therapy targets the placenta via ultrasound-guided injections. Researchers evaluated maternal, placental, and fetal responses by analyzing tissues, immunomodulatory proteins, and hormones (progesterone and estradiol). Findings highlight the potential of IGF1 nanoparticles to correct placental insufficiency by enhancing fetal growth, providing a groundbreaking advancement for in utero treatments. This research supports further exploration of nonviral gene therapies for improving pregnancy outcomes and combating FGR-related complications. Supported by ORIP (P51OD011106) and NICHD.
The Role of ATP Citrate Lyase in Myelin Formation and Maintenance
Schneider et al., Glia. 2024.
https://pubmed.ncbi.nlm.nih.gov/39318247/
Myelin formation by Schwann cells is critical for peripheral nervous system development and long-term neuronal function. The study examined how acetyl coenzyme A (acetyl-CoA), essential for lipid synthesis in myelin, is derived, with a focus on mitochondrial ATP citrate lysate (ACLY). By using both sexes in a Schwann cell–specific ACLY knockout mouse model, the authors reported that ACLY plays a role in acetyl-CoA supply for myelin maintenance but not myelin formation. ACLY is necessary for sustaining myelin gene expression and preventing nerve injury pathways. This work highlights a unique dependency on mitochondrial acetyl-CoA for Schwann cell integrity, providing insights into lipid metabolism in neuronal repair. Supported by ORIP (T35OD011078), NICHD, and NINDS.
Cdk8/CDK19 Promotes Mitochondrial Fission Through Drp1 Phosphorylation and Can Phenotypically Suppress Pink1 Deficiency in Drosophila
Liao et al., Nature Communications. 2024.
https://www.nature.com/articles/s41467-024-47623-8
Pink1 is a mitochondrial kinase implicated in Parkinson’s disease and is conserved among humans, rodents, and flies. In this study, researchers found that Cdk8 in Drosophila (i.e., the orthologue of vertebrate CDK8 and CDK19) promotes the phosphorylation of Drp1 (i.e., a protein required for mitochondrial fission) at the same residue as Pink1. Cdk8 is expressed in both the cytoplasm and nucleus, and neuronal loss of Cdk8 reduces fly life span and causes bang sensitivity and elongated mitochondria in both muscles and neurons. Overexpression of Cdk8 suppresses elevated levels of reactive oxygen species, mitochondrial dysmorphology, and behavioral defects in flies with low levels of Pink1. These findings suggest that Cdk8 regulates Drp1-mediated mitochondrial fission in a similar manner as Pink1 and may contribute to the development of Parkinson’s disease. Supported by ORIP (R24OD022005, R24OD031447, P40OD018537, P40OD010949), NICHD, and NINDS.
De Novo Variants in FRYL Are Associated With Developmental Delay, Intellectual Disability, and Dysmorphic Features
Pan et al., The American Journal of Human Genetics. 2024.
https://www.cell.com/ajhg/fulltext/S0002-9297(24)00039-9
FRY-like transcription coactivator (FRYL) belongs to a Furry protein family that is evolutionarily conserved from yeast to humans, and its functions in mammals are largely unknown. Investigators report 13 individuals who have de novo heterozygous variants in FRYL and one individual with a heterozygous FRYL variant that is not confirmed to be de novo. The individuals present with developmental delay; intellectual disability; dysmorphic features; and other congenital anomalies in cardiovascular, skeletal, gastrointestinal, renal, and urogenital systems. Using fruit flies, investigators provide evidence that haploinsufficiency in FRYL likely underlies a disorder in humans with developmental and neurological symptoms. Supported by ORIP (U54OD030165), NHLBI, NICHD, and NCATS.
Identification of Constrained Sequence Elements Across 239 Primate Genomes
Kuderna et al., Nature. 2024.
https://pubmed.ncbi.nlm.nih.gov/38030727/
Functional genomic elements that have acquired selective constraints specific to the primate order are prime candidates for understanding evolutionary changes in humans, but the selective constraints specific to the phylogenetic branch from which the human species ultimately emerged remain largely unidentified. Researchers constructed a genome-wide multiple sequence alignment of 239 primate species to better characterize constraint at noncoding regulatory sequences in the human genome. Their work reveals noncoding regulatory elements that are under selective constraint in primates but not in other placental mammals and are enriched for variants that affect human gene expression and complex traits in diseases. These findings highlight the important role of recent evolution in regulatory sequence elements differentiating primates, including humans, from other placental mammals. Supported by ORIP (P40OD024628), NHGRI, NIA, and NICHD.
Age-Associated DNA Methylation Changes in Xenopus Frogs
Morselli et al., Epigenetics. 2023.
https://www.tandfonline.com/doi/full/10.1080/15592294.2023.2201517
Age-associated changes in DNA methylation have not been characterized yet in amphibians, which include widely studied model organisms. Here the authors present clear evidence that the aquatic vertebrate species Xenopus tropicalis displays patterns of age-associated changes in DNA methylation. Whole-genome bisulfite sequencing profiles from skin samples of frogs representing young, mature, and old adults demonstrated that many of the methylation features and changes they observed are consistent with what is known in mammalian species, suggesting that the mechanism of age-related changes is conserved. The results of this study will allow researchers to leverage the unique resources available for Xenopus to study how DNA methylation relates to other hallmarks of aging. Supported by ORIP (P40OD010997, R24OD031956, R24OD030008) and NICHD.