Selected Grantee Publications
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- 5 results found
- Stem Cells/Regenerative Medicine
- U42
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.
Lipid Nanoparticle-Mediated mRNA Delivery to CD34+ Cells in Rhesus Monkeys
Kim et al., Nature Biotechnology. 2024.
https://pubmed.ncbi.nlm.nih.gov/39578569
Blood cells, which are derived from hematopoietic stem cells (HSCs), promote pathologies including anemia, sickle cell disease, immunodeficiency, and metabolic disorders when dysfunctional. Because of the morbidity that results from the bone marrow mobilization and chemotherapy patient conditioning of current HSC therapies, novel treatment strategies that deliver RNA to HSCs are needed. Researchers found a lipid nanoparticle (LNP), LNP67, that delivers messenger RNA (mRNA) to murine HSCs in vivo and human HSCs ex vivo without the use of a cKit-targeting ligand. When tested in 7- to 8-month-old male and female rhesus monkeys, LNP67 successfully delivered mRNA to CD34+ cells and liver cells without adverse effects. These results show the potential translational relevance of an in vivo LNP–mRNA drug. Supported by ORIP (U42OD027094, P51OD011107), NIDDK, and NCATS.
Bone Marrow Transplantation Increases Sulfatase Activity in Somatic Tissues in a Multiple Sulfatase Deficiency Mouse Model
Presa et al., Communications Medicine. 2024.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11502872/pdf/43856_2024_Article_648.pdf
Multiple Sulfatase Deficiency (MSD) is a rare genetic disorder where patients demonstrate loss of function mutations in the SUMF1 gene, resulting in a severe reduction in sulfatase activity. This enzyme deficiency causes impaired lysosomal function and widespread inflammation, leading to clinical manifestations like neurodegeneration, vision and hearing loss, and cardiac disease. The researchers evaluated the therapeutic potential of hematopoietic stem cell transplant (HSCT) to initiate cross-correction, where functional sulfatase enzymes secreted from the healthy donor cells are taken up to restore function in enzyme-deficient host cells. Bone marrow from healthy male and female B6-Sumf1(+/+) mice were transplanted into B6-Sumf1(S153P/S153P) mice, a model for MSD. The results showed that HSCT is suitable to rescue sulfatase activity in peripheral organs, such as the liver, spleen, and heart, but is not beneficial alone in inhibiting the central nervous system pathology of MSD. Supported by ORIP (U54OD020351, U54OD030187, U42OD010921) and NCI.
The Mutant Mouse Resource and Research Center (MMRRC) Consortium: The U.S.-Based Public Mouse Repository System
Agca et al., Mammalian Genome. 2024.
https://link.springer.com/article/10.1007/s00335-024-10070-3
The MMRRC has been the nation’s preeminent public repository and distribution archive of mutant mouse models for 25 years. The Consortium, with support from NIH, facilitates biomedical research by identifying, acquiring, evaluating, characterizing, preserving, and distributing a variety of mutant mouse strains to investigators around the world. Since its inception, the MMRRC has fulfilled more than 20,000 orders from 13,651 scientists at 8,441 institutions worldwide. Today, the MMRRC maintains an archive of mice, cryopreserved embryos and sperm, embryonic stem-cell lines, and murine monoclonal antibodies for nearly 65,000 alleles. The Consortium also provides scientific consultation, technical assistance, genetic assays, microbiome analysis, analytical phenotyping, pathology, husbandry, breeding and colony management, and more. Supported by ORIP (U42OD010918, U42OD010924, U42OD010983).
Limited Expansion of Human Hepatocytes in FAH/RAG2-Deficient Swine
Nelson et al., Tissue Engineering – Part A. 2021.
https://pubmed.ncbi.nlm.nih.gov/34309416/
The mammalian liver's regenerative ability has led researchers to engineer animals as incubators for expansion of human hepatocytes. Nelson et al. engineered immunodeficient swine to support expansion of human hepatocytes and identify barriers to their clinical application. Immunodeficient swine were engineered by knockout of the recombinase-activating gene 2 (RAG2) and fumarylacetoacetate hydrolase (FAH). Immature human hepatocytes (ihHCs) were injected into fetal swine by intrauterine cell transplantation (IUCT) at day 40 of gestation. They identified the mechanism of the eventual graft rejection by the intact NK cell population. They confirmed the presence of residual adaptive immunity in this model of immunodeficiency. Supported by ORIP (U42OD011140).