Selected Grantee Publications
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- 12 results found
- nia
- Alzheimer's Disease
- Microbiome
Mechanical Force of Uterine Occupation Enables Large Vesicle Extrusion From Proteostressed Maternal Neurons
Wang et al., eLife. 2024.
https://pubmed.ncbi.nlm.nih.gov/39255003
This study investigates how mechanical forces from uterine occupation influence large vesicle extrusion (exopher production) from proteostressed maternal neurons in Caenorhabditis elegans. Exophers, previously found to remove damaged cellular components, are poorly understood. Researchers demonstrate that mechanical stress significantly increases exopher release from touch receptor neurons (i.e., ALMR) during peak reproductive periods, coinciding with egg production. Genetic disruptions reducing reproductive activity suppress exopher extrusion, whereas interventions promoting egg retention enhance it. These findings reveal that reproductive and mechanical factors modulate neuronal stress responses, providing insight on how systemic physiological changes affect neuronal health and proteostasis, with broader implications for reproductive-neuronal interactions. Supported by ORIP (R24OD010943, P40OD010440), NIA, and NIGMS.
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.
Effect of Hormone Replacement Therapy on Amyloid Beta (Aβ) Plaque Density in the Rhesus Macaque Amygdala
Appleman et al., Frontiers in Aging Neuroscience. 2024.
https://www.frontiersin.org/articles/10.3389/fnagi.2023.1326747/full
Amyloid beta plaque density is associated with Alzheimer’s disease. In this study, the authors examined its concentration in aged female nonhuman primates’ cerebrospinal fluid, as well as in the amygdala, an area of the brain involved with emotion and memory. They set out to test the hypothesis that estrogen hormone replacement therapy can beneficially affect amygdala Aβ plaque density in “surgically menopausal” females (i.e., aged rhesus macaques that had undergone ovariectomy). Female rhesus macaques that received estrogen replacement therapy showed fewer amyloid plaques than those that did not receive the hormone. This effect was observed regardless of the type of diet that the animals consumed. These findings suggest that hormone replacement might be a helpful treatment to consider for Alzheimer’s disease. Supported by ORIP (P51OD011092, R24OD011895, S10OD025002) and NIA.
Intestinal Microbiota Controls Graft-Versus-Host Disease Independent of Donor–Host Genetic Disparity
Koyama et al., Immunity. 2023.
https://pubmed.ncbi.nlm.nih.gov/37480848/
Allogeneic hematopoietic stem cell transplantation is a curative therapy for hematopoietic malignancies and non-malignant diseases, but acute graft-versus-host disease (GVHD) remains a serious complication. Specifically, severe gut GVHD is the major cause of transplant-related mortality. Here, the authors show that genetically identical mice, sourced from different vendors, had distinct commensal bacterial compositions, which resulted in significantly discordant severity in GVHD. These studies highlight the importance of pre-transplant microbiota composition for the initiation and suppression of immune-mediated pathology in the gastrointestinal tract, demonstrating the impact of non-genetic environmental determinants to transplant outcome. Supported by ORIP (S10OD028685), NIA, NCI, and NHLBI.
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.
Mechanism of STMN2 Cryptic Splice-Polyadenylation and its Correction for TDP-43 Proteinopathies
Baughn et al., Science. 2023.
Loss of the RNA-binding protein TDP-43 from the nuclei of affected neurons is a hallmark of neurodegeneration in TDP-43 proteinopathies (e.g., amyotrophic lateral sclerosis, frontotemporal dementia). Loss of functional TDP-43 is accompanied by misprocessing of the stathmin-2 (STMN2) RNA precursor. Investigators determined the elements through which TDP‑43 regulates STMN2 pre‑mRNA processing and identified steric binding antisense oligonucleotides that are capable of restoring normal STMN2 protein and RNA levels. This approach is potentially applicable for human therapy. Supported by ORIP (U42OD010921), NIA, NCI, NIGMS, and NINDS.
A Class of Anti-Inflammatory Lipids Decrease with Aging in the Central Nervous System
Tan et al., Nature Chemical Biology. 2023.
https://doi.org/10.1038/s41589-022-01165-6
Impaired lipid metabolism in the brain has been implicated in neurological disorders of aging, yet analyses of lipid pathway changes with age have been lacking. The researchers examined the brain lipidome of mice of both sexes across the lifespan using untargeted lipidomics. They found that 3-sulfogalactosyl diacylglycerols (SGDGs) are structural components of myelin and decline with age in the central nervous system. The researchers discovered that SGDGs also are present in male human and rhesus macaque brains, demonstrating their evolutionary conservation in mammals. The investigators showed that SGDGs possess anti-inflammatory activity, suggesting a potential role for this lipid class in age-related neurodegenerative diseases. Supported by ORIP (P51OD011092), NIA, NCI, NIDDK, and NINDS.
Chronic TREM2 Activation Exacerbates Aβ-Associated Tau Seeding and Spreading
Jain et al., Journal of Experimental Medicine. 2023.
Using a mouse model for amyloidosis in which Alzheimer’s Disease (AD)–associated tau is injected into the brain to induce amyloid β (Aβ)–dependent tau seeding/spreading, investigators found that chronic administration of an activating triggering receptor expressed on myeloid cells 2 (TREM2) antibody increases microglial activation of dystrophic neurites surrounding Aβ plaques (NP) but increases NP-tau pathology and neuritic dystrophy without altering Aβ plaque burden. These data suggest that sustained microglial activation through TREM2 that does not result in strong myeloid removal might exacerbate Aβ-induced tau pathology, which could have important clinical implications. Supported by ORIP (S10OD021629) and NIA.
SARS-CoV-2 Infects Neurons and Induces Neuroinflammation in a Non-Human Primate Model of COVID-19
Beckman et al., Cell Reports. 2022.
https://www.doi.org/10.1016/j.celrep.2022.111573
SARS-CoV-2 causes brain fog and other neurological complications in some patients. It has been unclear whether SARS-CoV-2 infects the brain directly or whether central nervous system sequelae result from systemic inflammatory responses triggered in the periphery. Using a rhesus macaque model, researchers detected SARS-CoV-2 in the olfactory cortex and interconnected regions 7 days after infection, demonstrating that the virus enters the brain through the olfactory nerve. Neuroinflammation and neuronal damage were more severe in elderly monkeys with type 2 diabetes. The researchers found that in aged monkeys, SARS-CoV-2 traveled farther along nerve pathways to regions associated with Alzheimer's disease. Supported by ORIP (P51OD011107) and NIA.
Large Comparative Analyses of Primate Body Site Microbiomes Indicate That the Oral Microbiome Is Unique Among All Body Sites and Conserved Among Nonhuman Primates
Asangba et al., Microbiology Spectrum. 2022.
https://www.doi.org/10.1128/spectrum.01643-21
Microbiomes are critical to host health and disease, but large gaps remain in the understanding of the determinants, coevolution, and variation of microbiomes across body sites and host species. Thus, researchers conducted the largest comparative study of primate microbiomes to date by investigating microbiome community composition at eight distinct body sites in 17 host species. They found that the oral microbiome is unique in exhibiting notable similarity across primate species while being distinct from the microbiomes of all other body sites and host species. This finding suggests conserved oral microbial niche specialization, despite substantial dietary and phylogenetic differences among primates. Supported by ORIP (P51OD010425, P51OD011107, P40OD010965, R01OD010980), NIA, NIAID, and NICHD.