Selected Grantee Publications
Molecular and Cellular Evolution of the Primate Dorsolateral Prefrontal Cortex
Ma et al., Science. 2022.
https://www.doi.org/10.1126/science.abo7257
The dorsolateral prefrontal cortex (dlPFC) exists only in primates, lies at the center of high-order cognition, and is a locus of pathology underlying many neuropsychiatric diseases. The investigators generated single-nucleus transcriptome data profiling more than 600,000 nuclei from the dlPFC of adult humans, chimpanzees, rhesus macaques, and common marmosets of both sexes. Postmortem human samples were obtained from tissue donors. The investigators’ analyses delineated dlPFC cell-type homology and transcriptomic conservation across species and identified species divergence at the molecular and cellular levels, as well as potential epigenomic mechanisms underlying these differences. Expression patterns of more than 900 genes associated with brain disorders revealed a variety of conserved, divergent, and group-specific patterns. The resulting data resource will help to vertically integrate marmoset and macaque models with human-focused efforts to develop treatments for neuropsychiatric conditions. Supported by ORIP (P51OD011133), NIA, NICHD, NIDA, NIGMS, NHGRI, NIMH, and NINDS.
X Chromosome Agents of Sexual Differentiation
Arnold et al., Nature Reviews Endocrinology. 2022.
https://www.doi.org/10.1038/s41574-022-00697-0
Many diseases affect one sex disproportionately. A major goal of biomedical research is to understand which sex-biasing factors influence disease severity and to develop therapeutic strategies to target these factors. Two groups of such agents are sex chromosome genes and gonadal hormones. Researchers use the “four core genotypes” model to enable comparisons among animals with different sex chromosomes but the same type of sex hormones, which allows investigators to distinguish disease mechanisms influenced by the sex chromosomes. Supported by ORIP (R01OD030496, R21OD026560), NICHD, NIDDK, and NHLBI.
Wastewater Sequencing Reveals Early Cryptic SARS-CoV-2 Variant Transmission
Karthikeyan et al., Nature. 2022.
https://www.doi.org/10.1038/s41586-022-05049-6
The investigators explored the use of SARS-CoV-2 RNA concentration in wastewater as a practical approach to estimate community prevalence of COVID-19, detect emerging variants, and track regional infection dynamics. Two obstacles must be overcome to leverage wastewater-based genomic surveillance: low-quality sequence data and inability to estimate relative lineage abundance in mixed samples. The investigators developed and deployed improved virus concentration protocols and deconvolution software to fully resolve multiple virus strains from wastewater. Results indicate that emerging variants of concern were detected up to 14 days earlier in wastewater samples, and multiple instances of virus spread that were not captured by clinical genomic surveillance were identified by wastewater-based genomic surveillance. The study provides a scalable solution for wastewater genomic surveillance that allows early detection of SARS-CoV-2 variants and identification of cryptic transmission. The work suggests a critical, urgently needed methodology for early detection of emerging variants and early public health interventions. Supported by ORIP (S10OD026929), and NIAID.
Rbbp4 Loss Disrupts Neural Progenitor Cell Cycle Regulation Independent of Rb and Leads to Tp53 Acetylation and Apoptosis
Schultz-Rogers et al., Developmental Dynamics. 2022.
https://www.doi.org/10.1002/dvdy.467
Retinoblastoma binding protein 4 (Rbbp4) is a component of transcription regulatory complexes that control cell cycle gene expression by cooperating with the Rb tumor suppressor to block cell cycle entry. The authors used genetic analysis to examine the interactions of Rbbp4, Rb, and Tp53 in zebrafish neural progenitor cell cycle regulation and survival. Rbbp4 is upregulated across the spectrum of human embryonal and glial brain cancers, and it is essential for zebrafish neurogenesis. Rbbp4 loss leads to apoptosis and γ-H2AX in the developing brain that is suppressed by tp53 knockdown or maternal zygotic deletion. Mutant retinal neural precursors accumulate in M phase and fail to initiate G0 gene expression. Rbbp4; Rb1 double mutants show an additive effect on the number of M phase cells. The study demonstrates that Rbbp4 is necessary for neural progenitor cell cycle progression and initiation of G0, independent of Rb, and suggests that Rbbp4 is required for cell cycle exit and contributes to neural progenitor survival. Supported by ORIP (R24OD020166) and NIGMS.
Evolution of the Nitric Oxide Synthase Family in Vertebrates and Novel Insights in Gill Development
Annona et al., Proceedings of the Royal Society B. 2022.
https://www.doi.org/10.1098/rspb.2022.0667
Nitric oxide (NO) plays essential roles in biological systems, including cardiovascular homeostasis, neurotransmission, and immunity. Knowledge of NO synthases (NOS) is substantial, but the origin of nos gene orthologues in fishes, with respect to tetrapods, remains largely unknown. The recent identification of nos3 in the spotted gar, considered lost in this lineage, prompted the authors to explore nos gene evolution. Here, they report that nos2 experienced several lineage-specific gene duplications and losses. Additionally, nos3 was found to be lost independently in two teleost lineages, Elopomorpha and Clupeocephala. Further, the expression of at least one nos paralogue in gills of developing shark, bichir, sturgeon, and gar, but not in gills of lamprey, suggests nos expression in the gill might have arisen in the last common ancestor of gnathostomes. These results provide a framework for further research on the role of nos genes. Supported by ORIP (P40OD019794, R01OD011116).
Stromal P53 Regulates Breast Cancer Development, the Immune Landscape, and Survival in an Oncogene-Specific Manner
Wu et al., Molecular Cancer Research. 2022.
https://www.doi.org/10.1158/1541-7786.MCR-21-0960
Loss of stromal p53 function drives tumor progression in breast cancer, but the exact mechanisms have been relatively unexplored. Using mouse models, researchers demonstrated that loss of cancer-associated fibroblast (CAF) p53 enhances carcinoma formation driven by oncogenic KRAS G12D, but not ERBB2, in mammary epithelia. These results corresponded with increased tumor cell proliferation and DNA damage, as well as decreased apoptosis, in the KRAS G12D model. Furthermore, a gene cluster associated with CAF p53 deficiency was found to associate negatively with survival in microarray and heat map analyses. These data indicate that stromal p53 loss promotes mammary tumorigenesis in an oncogene-specific manner, influences the tumor immune landscape, and ultimately affects patient survival. Supported by ORIP (K01OD026527) and NCI.
Sunitinib Inhibits STAT3 Phosphorylation in Cardiac Muscle and Prevents Cardiomyopathy in the mdx Mouse Model of Duchenne Muscular Dystrophy
Oliveira-Santos et al., Human Molecular Genetics. 2022.
https://www.doi.org/10.1093/hmg/ddac042
Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy, affecting about 1 in 5,000 boys worldwide. DMD is a fatal X-linked genetic disorder that results from mutations in the dystrophin gene and leads to progressive muscular degeneration. Individuals with DMD often die at a young age from respiratory or heart failure. To date, few studies have examined the basis of cardiac failure associated with DMD, and no effective U.S. Food and Drug Administration (FDA)–approved treatment options are available. Using a mouse model of both sexes, researchers characterized the effectiveness of sunitinib, an FDA-approved small-molecule drug, in preventing DMD-related cardiomyopathy. The treatment reduced STAT3 activation in cardiac muscle and prevented cardiomyopathy disease progression. Inhibition of STAT3 activation in cardiac muscle can reduce inflammation and fibrosis and prevent heart failure. These findings demonstrate sunitinib’s potential as a novel treatment option for skeletal and cardiac muscle dysfunction in patients with DMD. Supported by ORIP (R42OD030543).
A Novel DPH5-Related Diphthamide-Deficiency Syndrome Causing Embryonic Lethality or Profound Neurodevelopmental Disorder
Shankar et al., Genetics in Medicine. 2022.
https://www.doi.org/10.1016/j.gim.2022.03.014
Neurodevelopmental disorders (NDDs) affect more than 3% of the pediatric population and often have associated neurologic or multisystem involvement. The underlying genetic etiology of NDDs remains unknown in many individuals. Investigators characterized the molecular basis of NDDs in children of both sexes with nonverbal NDDs from three unrelated families with distinct overlapping craniofacial features. The investigators also used a mouse model of both sexes to determine the pathogenicity of variants of uncertain significance, as well as genes of uncertain significance, to advance translational genomics and provide precision health care. They identified several variants in DPH5 as a potential cause of profound NDD. Their findings provide strong clinical, biochemical, and functional evidence for DPH5 variants as a novel cause of embryonic lethality or profound NDD with multisystem involvement. Based on these findings, the authors propose that “DPH5-related diphthamide deficiency syndrome” is a novel autosomal-recessive Mendelian disorder. Supported by ORIP (K01OD026608, U42OD012210) and NHGRI.
Allogeneic MHC‑Matched T‑Cell Receptor Α/Β‑Depleted Bone Marrow Transplants in SHIV‑Infected, ART‑Suppressed Mauritian Cynomolgus Macaques
Weinfurter et al., Scientific Reports. 2022.
https://www.doi.org/10.1038/s41598-022-16306-z
Allogeneic hematopoietic stem cell transplants are effective in reducing HIV reservoirs following antiretroviral therapy (ART). A better understanding of this mechanism could enable the development of safer and more efficacious HIV treatment regimens. In this study, the researchers used a Mauritian cynomolgus macaque model to study the effects of allogeneic major histocompatibility complex–matched α/β T cell–depleted bone marrow cell transplantation following infection with simian–human immunodeficiency virus (SHIV). The macaques began ART 6 to 16 weeks post-infection. In three of the four macaques, SHIV DNA was undetectable in blood but persisted in other tissues. These results suggest that extended ART likely is needed to eradicate the HIV reservoir following transplantation. In future studies, full donor engraftment should be balanced with suppression of graft-versus-host disease. Supported by ORIP (P51OD011106, R24OD021322), and NCI.
Innate Immune Regulation in HIV Latency Models
Olson et al., Retrovirology. 2022.
https://www.doi.org/10.1186/s12977-022-00599-z
Researchers are interested in developing therapeutic approaches to target latent HIV reservoirs, which are unaffected by antiretroviral therapy. Previous studies suggest that HIV latency might be related to viral RNA sensing, interferon (IFN) signaling, and IFN-stimulated gene (ISG) activation. In this study, the researchers evaluated responses to stimulation by retinoic acid–inducible gene I agonists and IFN in multiple CD4+ T cell line models for HIV latency. The models represented various aspects of latent infection and viral control. Several of the cell lines demonstrated reduced ISG induction, suggesting that long-term latency might be related to dysregulation of the downstream IFN response. These effects likely reflect transcriptional changes occurring within a core set of ISGs and altering IFN responses. Additional studies could provide insight into the functions of these ISGs in HIV latency. Supported by ORIP (P51OD010425), NCATS, and NIAID.