Selected Grantee Publications
Very-Long-Chain Fatty Acids Induce Glial-Derived Sphingosine-1-Phosphate Synthesis, Secretion, and Neuroinflammation
Chung et al., Cell Metabolism. 2023.
https://pubmed.ncbi.nlm.nih.gov/37084732/
Very-long-chain fatty acids (VLCFAs) are the most abundant fatty acids in myelin. During age‑associated degeneration of myelin, glia are exposed to increased levels of VLCFAs. Investigators previously described a novel phenotype in patients that harbors a novel variant in the peroxisomal enzyme ACOX1. Here, they report that that glial loss of ACOX1 leads to an increase of VLCFAs, which results in a concomitant increase in sphingosine-1-phosphate (S1P). They found that suppressing S1P function attenuates the pathological phenotypes caused by excess VLCFAs. This work suggests that lowering of VLCFAs and S1P could be applied as a treatment avenue for multiple sclerosis. Supported by ORIP (R24OD022005, R24OD031447, P40OD018537), NINDS, and NICHD
Exosome Cell Origin Affects In Vitro Markers of Tendon Repair in Ovine Macrophages and Tenocytes
von Stade et al., Tissue Engineering Part A. 2023.
https://pubmed.ncbi.nlm.nih.gov/36792933/
The underlying pathogenesis of rotator cuff tendinopathy reflects a combination of intrinsic and extrinsic factors, and recent work suggests that cell-to-cell communication drives the severity of tendon changes. Researchers are interested in the role of extracellular vesicles in tendon mechanical resilience, tissue organization, and anti-inflammatory macrophage phenotype predominance in response to tendon injury. In this study, investigators demonstrated how exosomes differ functionally based on cell source. This work suggests that control of exosome composition could lead to more effective therapies for certain tissues. Supported by ORIP (K01OD022982) and NCATS.
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.
Investigation of Monoclonal Antibody CSX-1004 for Fentanyl Overdose
Bremer et al., Nature Communications. 2023.
https://pubmed.ncbi.nlm.nih.gov/38052779/
The opioid crisis in the United States is primarily driven by the highly potent synthetic opioid fentanyl and has led to more than 70,000 overdose deaths annually; thus, new therapies for fentanyl overdose are urgently needed. Here, the authors present the first clinic-ready, fully human monoclonal antibody CSX-1004 with picomolar affinity for fentanyl and related analogs. In mice, CSX-1004 reverses fentanyl antinociception and the intractable respiratory depression caused by the ultrapotent opioid carfentanil. Using a highly translational nonhuman primate model for respiratory depression, they demonstrate CSX-1004-mediated protection from repeated fentanyl challenges for 3–4 weeks. These data establish the feasibility of CSX-1004 as a promising candidate medication for preventing and reversing fentanyl-induced overdose. Supported by ORIP (P40OD010938) and NIDA.
Tenth Aquatic Models of Human Disease Conference 2022 Workshop Report: Aquatics Nutrition and Reference Diet Development
Sharpton et al., Zebrafish. 2023.
https://pubmed.ncbi.nlm.nih.gov/38117219/
Standard reference diets (SRDs) for aquatic model organisms, vital for supporting scientific rigor and reproducibility, are yet to be adopted. At this workshop, the authors presented findings from a 7-month diet test study conducted across three aquatic research facilities: Zebrafish International Resource Center (University of Oregon), Kent and Sharpton laboratories (Oregon State University), and Xiphophorus Genetic Stock Center (Texas State University). They compared the effects of two commercial diets and a suggested zebrafish SRD on general fish husbandry, microbiome composition, and health in three fish species (zebrafish, Xiphophorus, and medaka), and three zebrafish wild-type strains. They reported outcomes, gathered community feedback, and addressed the aquatic research community's need for SRD development. Discussions underscored the influence of diet on aquatic research variability, emphasizing the need for SRDs to control cross-experiment and cross-laboratory reproducibility. Supported by ORIP (P40OD011021, R24OD011120, and R24OD010998) 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.
Host Immunity Associated With Spontaneous Suppression of Viremia in Therapy-Naïve Young Rhesus Macaques Following Neonatal SHIV Infection
Evangelous et al., Journal of Virology. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10688376/
Previously, investigators developed a pediatric rhesus macaque model for simian–human immunodeficiency virus infection that can be exploited to identify host immunity associated with viremia suppression. In the present study, they used the model (with male and female animals) to characterize humoral and cellular immunity and plasma biomarkers associated with spontaneous viremia suppression. They identified CD8-expressing cells and varied T-cell subsets that were associated with viremia suppression. Additionally, the authors observed intermediate monocytes with upregulation of inhibitory genes that previously had been reported only in cytotoxic cells. These findings suggest a complex immunologic milieu of viremia suppression in pediatric populations. Supported by ORIP (P51OD011092, U42OD010426) and NIAID.
Conjugation of HIV-1 Envelope to Hepatitis B Surface Antigen Alters Vaccine Responses in Rhesus Macaques
Nettere et al., NPJ Vaccines. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10673864/
Researchers are interested in developing an HIV-1 vaccine that improves upon the regimen used in the RV144 clinical trial. The authors tested the hypothesis that a conjugate vaccine based on the learned response to immunization with hepatitis B virus could be utilized to expand T-cell help and improve antibody production against HIV-1. Using juvenile rhesus macaques of both sexes, they evaluated the immunogenicity of their conjugate regimen. Their findings suggest that conjugate vaccination can engage both HIV-1 Env– and hepatitis B surface antigen–specific Tcell help and modify antibody responses at early time points. This work may help inform future efforts to improve the durability and efficacy of next-generation HIV vaccines. Supported by ORIP (P51OD011107, K01OD024877) and NIAID.
The Impact of SIV-Induced Immunodeficiency on Clinical Manifestation, Immune Response, and Viral Dynamics in SARS-CoV-2 Coinfection
Melton et al., bioRxiv. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10680717/
The effects of immunodeficiency caused by chronic HIV infection on COVID-19 have not been directly addressed in a controlled setting. Investigators conducted a pilot study in which two pigtail macaques (PTMs) chronically infected with SIVmac239 were exposed to SARS-CoV-2 and compared with SIV-naive PTMs infected with SARS-CoV-2. Despite the marked decrease in CD4+ T cells in the SIV-positive animals prior to exposure to SARS-CoV-2, investigators found that disease progression, viral persistence, and evolution of SARS-CoV-2 were comparable to the control group. These findings suggest that SIV-induced immunodeficiency alters the immune response to SARS-CoV-2 infection, leading to impaired cellular and humoral immunity. However, this impairment does not significantly alter the course of infection. Supported by ORIP (P51OD011104, U42OD013117, S10OD026800, S10OD030347) and NIAID.
Prime Editing–Mediated Correction of the CFTR W1282X Mutation in iPSCs and Derived Airway Epithelial Cells
Li et al., PLOS ONE. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10686454/
Cystic fibrosis (CF) is caused by recessive mutations in the CF transmembrane conductance regulator (CFTR) gene. Correction of nonsense CFTR mutations, which affects 10% of CF patients, via genomic editing represents a promising therapeutic approach. In this study, investigators tested whether prime editing can be applied as a potential therapeutic modality. Induced pluripotent stem cells (iPSCs) from a CF patient homozygous for the CFTR W1282X mutation were used. Studies demonstrated that prime editing corrected mutant allele in iPSCs, which effectively restored CFTR function in iPSC-derived airway epithelial cells and organoids. Supported by ORIP (R01OD01026594).