Selected Grantee Publications
Senescent-like Microglia Limit Remyelination Through the Senescence Associated Secretory Phenotype
Gross et al., Nature Communications. 2025.
https://www.nature.com/articles/s41467-025-57632-w
Multiple sclerosis (MS) is a chronic, immune-mediated demyelinating disease in which immune cells infiltrate the central nervous system and promote deterioration of myelin and neurodegeneration. The capacity to regenerate myelin in the central nervous system diminishes with age. In this study, researchers used 2- to 3-month-old (young), 12-month-old (middle-aged), and 18- to 22-month-old (aged) C57BL/6 male and female mice. Results showed an upregulation of the senescence marker P16ink4a (P16) in microglial and macrophage cells within demyelinated lesions. Notably, treatment of senescent cells using genetic and pharmacological senolytic methods leads to enhanced remyelination in young and middle-aged mice but fails to improve remyelination in aged mice. These results suggest that therapeutic targeting of senescence-associated secretory phenotype components may improve remyelination in aging and MS. Supported by ORIP (R24OD036199), NIA, NINDS, and NIMH.
Suppressing APOE4-Induced Neural Pathologies by Targeting the VHL-HIF Axis
Jiang et al., PNAS. 2025.
https://pubmed.ncbi.nlm.nih.gov/39874294
The ε4 variant of human apolipoprotein E (APOE4) is a major genetic risk factor for Alzheimer’s disease and increases mortality and neurodegeneration. Using Caenorhabditis elegans and male APOE-expressing mice, researchers determined that the Von Hippel-Lindau 1 (VHL-1) protein is a key modulator of APOE4-induced neural pathologies. This study demonstrated protective effects of the VHL-1 protein; the loss of this protein reduced APOE4-associated neuronal and behavioral damage by stabilizing hypoxia-inducible factor 1 (HIF-1), a transcription factor that protects against cellular stress and injury. Genetic VHL-1 inhibition also mitigated cerebral vascular injury and synaptic damage in APOE4-expressing mice. These findings suggest that targeting the VHL–HIF axis in nonproliferative tissues could reduce APOE4-driven mortality and neurodegeneration. Supported by ORIP (R24OD010943, R21OD032463, P40OD010440), NHGRI, NIA, and NIGMS.
A Murine Model of Trypanosoma brucei-Induced Myocarditis and Cardiac Dysfunction
Crilly et al., Microbiology Spectrum. 2025.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11792545
Trypanosoma brucei is a protozoan parasite that causes human and animal African trypanosomiases, HAT and AAT, respectively. Cardiac symptoms are commonly reported in HAT patients, and intracardiac parasites with accompanying myocarditis have been observed in both natural hosts and animal models for T. brucei infection. A clinically relevant, reproducible murine model for T. brucei–associated cardiomyopathy is currently unavailable. The researchers developed a 7- to 10-week-old C57Bl/6J male and female mouse model for T. brucei infection that demonstrates myocarditis, elevated serum levels of NT-proBNP, and electrocardiographic abnormalities, recapitulating the clinical features of infection. The results demonstrate the importance of interstitial space in T. brucei colonization and provide a relevant, reproducible murine model to investigate the pathogenesis and potential therapeutics of T. brucei-mediated heart damage. Supported by ORIP (T32OD011089, S10OD026859), NCI, and NIA.
Functional Differences Between Rodent and Human PD-1 Linked to Evolutionary Divergence
Masubuchi et al., Science Immunology. 2025.
https://pubmed.ncbi.nlm.nih.gov/39752535/
Programmed cell death protein 1 (PD-1), an immune checkpoint receptor, regulates immunity against cancer. Rodent models (e.g., mice) do not exhibit the same response rates and immune-related adverse effects to PD-1 blocking drugs as patients with cancer. Only 59.6% amino acid sequence identity is conserved in human PD-1 (hu PD-1) and mouse PD-1 (mo PD-1). Researchers used mouse tumor models, coculture assays, and biophysical assays to determine key functional and biochemical differences between hu PD-1 and mo PD-1. HuPD-1 demonstrates stronger suppressive activity of interleukin-2 secretion and CD69 expression than mo PD-1 because of the ectodomain and intracellular domain, but not the transmembrane domain. Analysis of rodent evolution demonstrated that other inhibitory immunoreceptors were positively selected or had selection intensification over PD-1. Understanding the conservation and divergence of PD-1 signaling at the molecular level in humans compared with mice is needed to properly translate preclinical data to clinical therapeutics. Supported by ORIP (S10OD026929), NCI, and NIA.
Matrikine Stimulation of Equine Synovial Fibroblasts and Chondrocytes Results in an In Vitro Osteoarthritis Phenotype
Gagliardi et al., Journal of Orthopaedic Research. 2025.
https://pubmed.ncbi.nlm.nih.gov/39486895
Advancements in therapy development for osteoarthritis (OA) currently are limited due to a lack of physiologically relevant in vitro models. This study aimed to understand the effect of matrikine stimulation, using human recombinant fibronectin fragment containing domains 7–10 (FN7–10), on equine synovial fibroblasts and chondrocytes. Inflammatory cytokines, chemokines, and matrix degradation genes in equine synovial fibroblasts and chondrocytes were significantly altered in response to FN7–10 stimulation; marked upregulation was observed in interleukin-6 (IL-6), IL-4, IL-10, matrix metalloproteinase 1 (MMP1), MMP3, MMP13, CCL2/MCP1, and CXCL6/GCP-2 gene expression. Only IL-6 protein production was significantly increased in media isolated from cells stimulated with FN7–10. These results support the potential use of equine synovial fibroblasts and chondrocytes—employing FN7–10—as representative in vitro models to study OA. Supported by ORIP (T32OD011130) and NIAMS.
Impaired Skeletal Development by Disruption of Presenilin-1 in Pigs and Generation of Novel Pig Models for Alzheimer's Disease
Uh et al., Journal of Alzheimer's Disease. 2024.
https://pubmed.ncbi.nlm.nih.gov/39177593/
This study explored the effects of presenilin 1 (PSEN1) disruption on vertebral malformations in male and female PSEN1 mutant pigs. Researchers observed significant skeletal impairments and early deaths in pigs with a PSEN1 null mutation, mirroring phenotypes seen in mouse models of Alzheimer’s disease (AD). This porcine model provides valuable insights into pathological hallmarks of PSEN1 mutations in AD, offering a robust platform of therapeutic exploration. The findings establish pigs as an essential translational model for AD, enabling advanced studies on pathophysiology and treatment development for human skeletal and neurological conditions. Supported by ORIP (U42OD011140), NHLBI, NIA, NIAID.
Loss of Lymphatic IKKα Disrupts Lung Immune Homeostasis, Drives BALT Formation, and Protects Against Influenza
Cully et al., Immunohorizons. 2024.
https://pubmed.ncbi.nlm.nih.gov/39007717/
Tertiary lymphoid structures (TLS) have context-specific roles, and more work is needed to understand how they function in separate diseases to drive or reduce pathology. Researchers showed previously that lymph node formation is ablated in mice constitutively lacking IκB kinase alpha (IKKα) in lymphatic endothelial cells (LECs). In this study, they demonstrated that loss of IKKα in lymphatic endothelial cells leads to the formation of bronchus-associated lymphoid tissue in the lung. Additionally, they showed that male and female mice challenged with influenza A virus (IAV) exhibited markedly improved survival rates and reduced weight loss, compared with littermate controls. They concluded that ablating IKKα in this tissue reduces the susceptibility of the mice to IAV infection through a decrease in proinflammatory stimuli. This work provides a new model to explore the mechanisms of TLS formation and the immunoregulatory function of lung lymphatics. Supported by ORIP (T35OD010919), NHLBI, NIAID, and NIAMS.
Murine MHC-Deficient Nonobese Diabetic Mice Carrying Human HLA-DQ8 Develop Severe Myocarditis and Myositis in Response to Anti-PD-1 Immune Checkpoint Inhibitor Cancer Therapy
Racine et al., Journal of Immunology. 2024.
Myocarditis has emerged as a relatively rare but often lethal autoimmune complication of checkpoint inhibitor (ICI) cancer therapy, and significant mortality is associated with this phenomenon. Investigators developed a new mouse model system that spontaneously develops myocarditis. These mice are highly susceptible to myocarditis and acute heart failure following anti-PD-1 ICI-induced treatment. Additionally, the treatment accelerates skeletal muscle myositis. The team performed characterization of cardiac and skeletal muscle T cells using histology, flow cytometry, adoptive transfers, and RNA sequencing analyses. This study sheds light on underlying immunological mechanisms in ICI myocarditis and provides the basis for further detailed analyses of diagnostic and therapeutic strategies. Supported by ORIP (U54OD020351, U54OD030187), NCI, NIA, NIDDK, and NIGMS.
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.
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.