Selected Grantee Publications
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.
Association of Age at Menopause and Hormone Therapy Use With Tau and β-Amyloid Positron Emission Tomography
Coughlan et al., JAMA Neurology. 2023.
https://pubmed.ncbi.nlm.nih.gov/37010830/
To understand the predominance (70%) of women among individuals with Alzheimer’s disease, the investigators studied regional tau and β-amyloid (Aβ) in relation to age at menopause and hormone therapy (HT) in postmenopausal women and age-matched men using positron emission tomography. The study demonstrated that females exhibited higher tau deposition compared with age-matched males, particularly in the setting of elevated Aβ; earlier age at menopause and late initiation of HT were associated with increased tau vulnerability. This study suggests female individuals with these conditions may be at higher risk of pathological burden. Supported by ORIP (S10OD025245), NIA, and NICHD.
HIV, Asymptomatic STI, and the Rectal Mucosal Immune Environment Among Young Men Who Have Sex With Men
Van Doren et al., PLOS Pathogens. 2023.
https://www.doi.org/10.1371/journal.ppat.1011219
Young men who have sex with men (YMSM) are affected disproportionately by HIV and bacterial sexually transmitted infections (STIs) and therefore are likely to face an increased burden of associated chronic inflammation. Researchers studied the immunologic effects and interactions of HIV and bacterial STIs, as well as their effects on the rectal mucosal immune environment, among various populations of YMSM. Their findings suggest that asymptomatic bacterial STIs could contribute to inflammation, particularly among YMSM with HIV. This study provides insights into the immunopathogenesis of asymptomatic bacterial STIs and identifies a syndemic interaction between HIV and bacterial STIs in YMSM. Supported by ORIP (P51OD011132), NIAID, and NICHD.
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.
Cerebrospinal Fluid Protein Markers Indicate Neuro-Damage in SARS-CoV-2-Infected Nonhuman Primates
Maity et al., Molecular & Cellular Proteomics. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9981268/
In this study, researchers examined the proteins expressed in cerebrospinal fluid (CSF) in nonhuman primates (NHPs) to better understand how COVID-19 infection can result in brain pathology, a common outcome. The study found that even in NHPs with minimal or mild COVID‑19, CSF proteins were significantly dysregulated compared with uninfected NHPs. Furthermore, the most affected proteins were enriched in the same brain regions that show lesions after COVID-19 infection, including the cerebral cortex, basal ganglia, and brain stem. Collectively, these regions have wide-ranging control over such crucial functions as cognition, motor control, and breathing, showing how even mild COVID-19 infection can result in significant neurological impairment. Supported by ORIP (P51OD011104, S10OD032453), NIGMS, NCI, and NICHD.
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.
Impaired Placental Hemodynamics and Function in a Non-Human Primate Model of Gestational Protein Restriction
Lo et al., Scientific Reports. 2023.
https://www.nature.com/articles/s41598-023-28051-y
Maternal malnutrition is a global health epidemic that adversely affects fetal outcomes and results in long-term health complications in children. Investigators used a previously developed model in nonhuman primates for gestational protein restriction to study the impact of undernutrition, specifically protein deficiency, on placental function and pregnancy outcomes. The data demonstrate that a 50% protein-restricted diet reduces maternal placental perfusion, decreases fetal oxygen availability, and increases fetal mortality. These alterations in placental hemodynamics could partly explain human growth restriction and stillbirth seen with severe protein restriction in developing countries. Supported by ORIP (P51OD011092) and NICHD.
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.
Mendelian Gene Identification through Mouse Embryo Viability Screening
Cacheiro et al., Genome Medicine. 2022.
https://www.doi.org/10.1186/s13073-022-01118-7
The investigators dissected phenotypic similarities between patients and model organisms by assessing the embryonic stage at which homozygous loss of function results in lethality in mice of both sexes obtained from the International Mouse Phenotyping Consortium. Information on knockout mouse embryo lethality can be used to prioritize candidate genes associated with certain disorders. Access to unsolved cases from rare-disease genome sequencing programs allows for the screening of those genes for potentially pathogenic variants, which could lead to a diagnosis and new potential treatment options to inform the management of human disease. Supported by ORIP (UM1OD023221, UM1OD023222, U42OD011174) and NHGRI.