Selected Grantee Publications
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- 10 results found
- Alzheimer's Disease
- Microbiome
- 2024
Multimodal Analysis of Dysregulated Heme Metabolism, Hypoxic Signaling, and Stress Erythropoiesis in Down Syndrome
Donovan et al., Cell Reports. 2024.
https://pubmed.ncbi.nlm.nih.gov/39120971
Down syndrome (DS), a genetic condition caused by the presence of an extra copy of chromosome 21, is characterized by intellectual and developmental disability. Infants with DS often suffer from low oxygen saturation, and DS is associated with obstructive sleep apnea. Investigators assessed the role that hypoxia plays in driving health conditions that are comorbid with DS. A multiomic analysis showed that people with DS exhibit elevated heme metabolism and activated stress erythropoiesis, which are indicators of chronic hypoxia; these results were recapitulated in a mouse model for DS. This study identified hypoxia as a possible mechanism underlying several conditions that co-occur with DS, including congenital heart defects, seizure disorders, autoimmune disorders, several leukemias, and Alzheimer's disease. Supported by ORIP (R24OD035579), NCATS, NCI, and NIAID.
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.
Stat3 Mediates Fyn Kinase-Driven Dopaminergic Neurodegeneration and Microglia Activation
Siddiqui et al., Disease Models & Mechanisms. 2024.
https://pubmed.ncbi.nlm.nih.gov/39641161
The FYN gene is a risk locus for Alzheimer’s disease and several other neurodegenerative disorders. FYN encodes Fyn kinase, and previous studies have shown that Fyn signaling in dopaminergic neurons and microglia plays a role during neurodegeneration. This study investigated Fyn signaling using zebrafish that express a constitutively active Fyn Y531F mutant in neural cells. Activated neural Fyn signaling in the mutant animals resulted in dopaminergic neuron loss and induced inflammatory cytokine expression when compared with controls. Transcriptomic and chemical inhibition analyses revealed that Fyn-driven changes were dependent on the Stat3 and NF-κB signaling pathways, which work synergistically to activate neuronal inflammation and degeneration. This study provides insight into the mechanisms underlying neurodegeneration, identifying Stat3 as a novel effector of Fyn signaling and a potential translational target. Supported by ORIP (R24OD020166).
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.
The Mutant Mouse Resource and Research Center (MMRRC) Consortium: The U.S.-Based Public Mouse Repository System
Agca et al., Mammalian Genome. 2024.
https://link.springer.com/article/10.1007/s00335-024-10070-3
The MMRRC has been the nation’s preeminent public repository and distribution archive of mutant mouse models for 25 years. The Consortium, with support from NIH, facilitates biomedical research by identifying, acquiring, evaluating, characterizing, preserving, and distributing a variety of mutant mouse strains to investigators around the world. Since its inception, the MMRRC has fulfilled more than 20,000 orders from 13,651 scientists at 8,441 institutions worldwide. Today, the MMRRC maintains an archive of mice, cryopreserved embryos and sperm, embryonic stem-cell lines, and murine monoclonal antibodies for nearly 65,000 alleles. The Consortium also provides scientific consultation, technical assistance, genetic assays, microbiome analysis, analytical phenotyping, pathology, husbandry, breeding and colony management, and more. Supported by ORIP (U42OD010918, U42OD010924, U42OD010983).
Time of Sample Collection Is Critical for the Replicability of Microbiome Analyses
Allaband et al., Nature Metabolism. 2024.
https://pubmed.ncbi.nlm.nih.gov/38951660/
Lack of replicability remains a challenge in microbiome studies. As the microbiome field moves from descriptive and associative research to mechanistic and interventional studies, being able to account for all confounding variables in the experimental design will be critical. Researchers conducted a retrospective analysis of 16S amplicon sequencing studies in male mice. They report that sample collection time affects the conclusions drawn from microbiome studies. The lack of consistency in the time of sample collection could help explain poor cross-study replicability in microbiome research. The effect of diurnal rhythms on the outcomes and study designs of other fields is unknown but is likely significant. Supported by ORIP (T32OD017863), NCATS, NCI, NHLBI, NIAAA, NIAID, NIBIB, NIDDK, and NIGMS.
Natural Killer–Like B Cells Are a Distinct but Infrequent Innate Immune Cell Subset Modulated by SIV Infection of Rhesus Macaques
Manickam et al., PLOS Pathogens. 2024.
https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1012223
Natural killer–like B (NKB) cells express both natural killer (NK) and B cell receptors. Intracellular signaling proteins and trafficking markers were expressed differentially on naive NKB cells. CD20+ NKG2A/C+ NKB cells were identified in organs and lymph nodes of naive rhesus macaques (RMs). Single-cell RNA sequencing (scRNAseq) of sorted NKB cells confirmed that NKB cells are unique, and transcriptomic analysis of naive splenic NKB cells by scRNAseq showed that NKB cells undergo somatic hypermutation and express Ig receptors, similar to B cells. Expanded NKB frequencies were observed in RM gut and buccal mucosa after simian immunodeficiency virus (SIV) infection, and mucosal and peripheral NKB cells were associated with colorectal cytokine milieu and oral microbiome changes. NKB cells gated on CD3-CD14-CD20+NKG2A/C+ cells were inclusive of transcriptomically conventional B and NK cells in addition to true NKB cells, confounding accurate phenotyping and frequency recordings. Supported by ORIP (P51OD011132, S10OD026799) and NIAID.
Intestinal Epithelial Adaptations to Vertical Sleeve Gastrectomy Defined at Single-Cell Resolution
Koch-Laskowski et al., Genomics. 2024.
https://pubmed.ncbi.nlm.nih.gov/38309446/
Perturbations in the intestinal epithelium have been linked to the pathogenesis of metabolic disease. Bariatric procedures, such as vertical sleeve gastrectomy (VSG), cause gut adaptations that induce robust metabolic improvements. Using a male mouse model, the authors assessed the effects of VSG on different cell lineages of the small intestinal epithelium. They show that Paneth cells display increased expression of the gut peptide Reg3g after VSG. Additionally, VSG restores pathways pertaining to mitochondrial respiration and cellular metabolism, especially within crypt-based cells. Overall, this work demonstrates how adaptations among specific cell types can affect gut epithelial homeostasis; these findings can help researchers develop targeted, less invasive treatment strategies for metabolic disease. Supported by ORIP (F30OD031914), NCI, and NIDDK.
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.
Antibiotic-Induced Gut Dysbiosis Elicits Gut–Brain–Axis Relevant Multi-Omic Signatures and Behavioral and Neuroendocrine Changes in a Nonhuman Primate Model
Hayer et al., Gut Microbes. 2024.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10826635/
Gut microbiome–mammalian cell interactions influence the development of metabolic, immune-mediated, and neuropsychiatric disorders. Dysbiosis of the gut microbiome has been linked to behavioral characteristics in previous nonhuman primate (NHP) studies, but additional studies using NHPs are necessary to understand microbiota–gut–brain communication. The authors sought to evaluate whether antibiotic-induced gut dysbiosis can elicit changes in gut metabolites and behavior indicative of gut–brain axis disruption in common marmosets of both sexes. For the first time in an NHP model, this study demonstrated that antibiotics induce gut dysbiosis, alter gut metabolites relevant to gut–brain communication, affect neuroendocrine responses in response to stressful stimuli, and change social behavior. Supported by ORIP (K01OD030514), NCI, and NIGMS.