Selected Grantee Publications
Newly Identified Roles for PIEZO1 Mechanosensor in Controlling Normal Megakaryocyte Development and in Primary Myelofibrosis
Abbonante et al., American Journal of Hematology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38165047/
Mechanisms through which mature megakaryocytes (Mks) and their progenitors sense the bone marrow extracellular matrix to promote lineage differentiation are only partially understood. The authors report that PIEZO1, a mechanosensitive cation channel, is expressed in mouse and human Mks, and activation of PIEZO1 increased the number of immature Mks in mice. Piezo1/2 knockout mice show an increase in Mk size and platelet count, both at basal state and upon marrow regeneration. Together, these data suggest that PIEZO1 places a brake on Mk maturation and platelet formation in physiology, and its upregulation might contribute to aggravating disease. Supported by ORIP (K01OD025290), NHGRI, NHLBI, and NCATS.
The Monarch Initiative in 2024: An Analytic Platform Integrating Phenotypes, Genes and Diseases Across Species
Putman et al., Nucleic Acids Research. 2024.
https://pubmed.ncbi.nlm.nih.gov/38000386/
The Monarch Initiative aims to bridge the gap between the genetic variations, environmental determinants, and phenotypic outcomes critical for translational research. The Monarch app provides researchers access to curated data sets with information on genes, phenotypes, and diseases across species and advanced analysis tools for such diverse applications as variant prioritization, deep phenotyping, and patient profile matching. Researchers describe upgrades to the app, including scalable cloud-based infrastructure, simplified data ingestion and knowledge graph integration systems, enhanced data mapping and integration standards, and a new user interface with novel search and graph navigation features. A customized plugin for OpenAI’s ChatGPT allows the use of large language models to interrogate knowledge in the Monarch graph and increase the reliability of the responses of Monarch’s analytic tools. These upgrades will enhance clinical diagnosis and the understanding of disease mechanisms. Supported by ORIP (R24OD011883), NLM, and NHGRI.
Lipid Droplets and Peroxisomes Are Co-Regulated to Drive Lifespan Extension in Response to Mono-Unsaturated Fatty Acids
Papsdorf et al., Nature Cell Biology. 2023.
https://www.nature.com/articles/s41556-023-01136-6
Investigators studied the mechanism by which mono-unsaturated fatty acids (MUFAs) extend longevity. They found that MUFAs upregulated the number of lipid droplets in fat storage tissues of Caenorhabditis elegans, and increased lipid droplets are necessary for MUFA-induced longevity and predicted remaining lifespan. Lipidomics data revealed that MUFAs modify the ratio of membrane lipids and ether lipids, which leads to decreased lipid oxidation in middle-aged individuals. MUFAs also upregulate peroxisome number. A targeted screen revealed that induction of both lipid droplets and peroxisomes is optimal for longevity. This study opens new interventive avenues to delay aging. Supported by ORIP (S10OD025004, S10OD028536, P40OD010440), NIA, NCCIH, NIDDK, and NHGRI.
Whole Genome Analysis for 163 gRNAs in Cas9-Edited Mice Reveals Minimal Off-Target Activity
Peterson et al., Communications Biology. 2023.
https://www.nature.com/articles/s42003-023-04974-0
CRISPR/Cas9 genome editing offers potential as a treatment for genetic diseases in humans. Using whole-genome sequencing, investigators assessed the occurrence of Streptococcus pyogenes Cas9–induced off-target mutagenesis in Cas9-edited founder mice. Sequencing and computational analysis indicate that the risk of Cas9 cutting at predicted off-target sites is lower than random genetic variation introduced into the genomes of inbred mice through mating. These findings will inform future design and use of Cas9-edited animal models and can provide context for evaluating off-target potential in genetically diverse patient populations. Supported by ORIP (UM1OD023221, UM1OD023222) and NHGRI.
Resolution of Structural Variation in Diverse Mouse Genomes Reveals Chromatin Remodeling due to Transposable Elements
Ferraj et al., Cell Genomics. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10203049/
Diverse inbred mouse strains are important biomedical research models, yet genome characterization of many strains is fundamentally lacking in comparison with humans. Here, investigators used long-read whole genome sequencing to assemble the genomes of 20 diverse inbred laboratory strains of mice. From whole-genome comparisons, they generated a sequence-resolved callset of 413,758 structural variants. These data are presented as a comprehensive resource that can be used for future genomic studies, aid in modeling and studying the effects of genetic variation, and enhance genotype-to-phenotype research. Supported by ORIP (R24OD021325), NCI, NIGMS, and NHGRI.
Topologically Associating Domain Boundaries Are Required for Normal Genome Function
Rajderkar et al., Communications Biology. 2023.
https://www.nature.com/articles/s42003-023-04819-w
Eukaryotic genomes fold into topologically associating domains (TADs), sub-megabase-scale chromatin segments characterized by high intra-domain chromatin contact frequency. Investigators selected eight independent TAD boundaries in the vicinity of genes active during embryonic development, individually deleted these boundaries from the mouse genome, and systematically examined the consequences on survival, genome organization, gene expression, and development. Results of the studies demonstrate the importance of TAD boundary sequences for in vivo genome function and reinforce the critical need to consider the potential pathogenicity of deletions affecting TAD boundaries in clinical genetics screening. Supported by ORIP (UM1OD023221), NIGMS, and NHGRI.
Naturally Occurring Osteochondrosis Latens Lesions Identified by Quantitative and Morphological 10.5 T MRI in Pigs
Armstrong et al., Journal of Orthopaedic Research. 2023.
https://pubmed.ncbi.nlm.nih.gov/35716161/
Juvenile osteochondritis dissecans (JOCD) is a pediatric orthopedic disorder that is associated with pain and gait deficits. JOCD lesions form in the knee, elbow, and ankle joints and can progress to early-onset osteoarthritis. In this study, researchers used a noninvasive magnetic resonance imaging (MRI) method to identify naturally occurring lesions in intact knee and elbow joints of juvenile pigs. This work can be applied to noninvasive identification and monitoring of early JOCD lesions and determination of risk factors that contribute to their progression in children. Supported by ORIP (K01OD021293, T32OD010993), NIAMS, and NIBIB.
TMEM161B Modulates Radial Glial Scaffolding in Neocortical Development
Wang et al., PNAS. 2023.
https://www.pnas.org/doi/10.1073/pnas.2209983120
Neocortical folding (i.e., gyrification) is a fundamental evolutionary mechanism allowing the expansion of cortical surface area and increased cognitive function. This study identifies TMEM161B in gyral spacing in humans, likely affecting radial glial cell polarity through effects on the actin cytoskeleton. Patients carrying TMEM161B mutations exhibit striking neocortical polymicrogyria and intellectual disability. TMEM161B knockout mice fail to develop midline hemispheric cleavage, whereas knock-in of patient mutations and patient-derived brain organoids show defects in apical cell polarity and radial glial scaffolding. The data implicating TMEM161B in murine holoprosencephaly may suggest shared mechanisms between the formation of the brain midline and cortical gyrification. Supported by ORIP (U54OD030187), NINDS, and NHGRI.
Gigapixel Imaging With a Novel Multi-Camera Array Microscope
Thomson et al., eLife. 2022.
https://www.doi.org/10.7554/eLife.74988
The dynamics of living organisms are organized across many spatial scales. The investigators created assembled a scalable multi-camera array microscope (MCAM) that enables comprehensive high-resolution, large field-of-view recording from multiple spatial scales simultaneously, ranging from structures that approach the cellular scale to large-group behavioral dynamics. By collecting data from up to 96 cameras, they computationally generated gigapixel-scale images and movies with a field of view over hundreds of square centimeters at an optical resolution of 18 µm. This system allows the team to observe the behavior and fine anatomical features of numerous freely moving model organisms on multiple spatial scales (e.g., larval zebrafish, fruit flies, slime mold). Overall, by removing the bottlenecks imposed by single-camera image acquisition systems, the MCAM provides a powerful platform for investigating detailed biological features and behavioral processes of small model organisms. Supported by ORIP (R44OD024879), NIEHS, NCI, and NIBIB.
Two Neuronal Peptides Encoded from a Single Transcript Regulate Mitochondrial Complex III in Drosophila
Bosch et al., eLife. 2022.
https://www.doi.org/10.7554/eLife.82709
Transcripts with small open-reading frames (smORFs) are underrepresented in genome annotations. Functions of peptides encoded by smORFs are poorly understood. The investigators systematically characterized human-conserved smORF genes in Drosophila and found two peptides, Sloth1 and Sloth2, that are highly expressed in neurons. They showed that Sloth1 and Sloth2 are paralogs with high sequence similarity but are not functionally redundant. Loss of either peptide resulted in lethality, impaired mitochondrial function, and neurodegeneration. This work suggests the value of phenotypic analysis of smORFs using Drosophila as a model. Supported by ORIP (R24OD019847), NHGRI, and NIGMS.