Selected Grantee Publications
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- 40 results found
- Alzheimer's Disease
- Microbiome
The Contribution of Maternal Oral, Vaginal, and Gut Microbiota to the Developing Offspring Gut
Russell et al., Scientific Reports. 2023.
https://www.nature.com/articles/s41598-023-40703-7#Ack1
The maturation process of the gut microbiota (GM) is an essential process for life-long health that is defined by the acquisition and colonization of microorganisms in the gut and the subsequent immune system induction that occurs during early life. To address significant knowledge gaps in this area, investigators characterized the neonatal fecal and ileal microbiota of entire litters of mice at multiple pre-weaning time-points. Results indicated that specific-pathogen-free mouse microbiotas undergo a dynamic and somewhat characteristic maturation process, culminating by roughly two to three weeks of age. Prior to that, the neonatal GM is more similar in composition to the maternal oral microbiota, as opposed to the vaginal and fecal microbiotas. Further studies are needed to expand our knowledge regarding the effect of these developmental exposures on host development. Supported by ORIP (U42OD010918, R03OD028259).
Disentangling the Link Between Zebrafish Diet, Gut Microbiome Succession, and Mycobacterium chelonae Infection
Sieler et al., Animal Microbiome. 2023.
https://pubmed.ncbi.nlm.nih.gov/37563644/
Despite the long-established importance of zebrafish (Danio rerio) as a model organism and their increasing use in microbiome-targeted studies, relatively little is known about how husbandry practices involving diet impact the zebrafish gut microbiome. Given the microbiome's important role in mediating host physiology and the potential for diet to drive variation in microbiome composition, the authors sought to clarify how three different dietary formulations that are commonly used in zebrafish facilities impact the gut microbiome. They report that diet drives the successional development of the gut microbiome, as well as its sensitivity to exogenous exposure. Consequently, investigators should carefully consider the role of diet in their microbiome zebrafish investigations, especially when integrating results across studies that vary by diet. Supported by ORIP (R24OD010998) and NIEHS.
A Germ-Free Humanized Mouse Model Shows the Contribution of Resident Microbiota to Human-Specific Pathogen Infection
Wahl et al., Nature Biotechnology. 2023.
https://www.nature.com/articles/s41587-023-01906-5
Germ-free (GF) mice are of limited value in the study of human-specific pathogens because they do not support their replication. In this report, investigators developed a GF humanized mouse model using the bone marrow–liver–thymus platform to provide a robust and flexible in vivo model that can be used to study the role of resident microbiota in human health and disease. They demonstrated that resident microbiota promote viral acquisition and pathogenesis by using two human-specific pathogens, Epstein–Barr virus and HIV. Supported by ORIP (P40OD010995), FIC, NIAID, NCI, and NIDDK.
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.
Gut Microbiome Dysbiosis in Antibiotic-Treated COVID-19 Patients Is Associated with Microbial Translocation and Bacteremia
Bernard-Raichon et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-33395-6
The investigators demonstrated that SARS-CoV-2 infection induced gut microbiome dysbiosis in male mice. Samples collected from human COVID-19 patients of both sexes also revealed substantial gut microbiome dysbiosis. Analysis of blood culture results testing for secondary microbial bloodstream infections with paired microbiome data indicated that bacteria might translocate from the gut into the systemic circulation of COVID-19 patients. These results were consistent with a direct role for gut microbiome dysbiosis in enabling dangerous secondary infections during COVID-19. Supported by ORIP (S10OD021747), NCI, NHLBI, NIAID, and NIDDK.
Sociability in a Non-Captive Macaque Population Is Associated with Beneficial Gut Bacteria
Johnson et al., Frontiers in Microbiology. 2022.
https://www.doi.org/10.3389/fmicb.2022.1032495
Social connections are essential for good health and well-being in social animals, such as humans and other primates. Increasingly, evidence suggests that the gut microbiome—through the so-called “gut–brain axis”—plays a key role in physical and mental health and that bacteria can be transmitted socially (e.g., through touch). Here, the authors explore behavioral variation in non‑captive rhesus macaques of both sexes with respect to the abundance of specific bacterial genera. Their results indicate that microorganisms whose abundance varies with individual social behavior also have functional links to host immune status. Overall, these findings highlight the connections between social behavior, microbiome composition, and health in an animal population. Supported by ORIP (P40OD012217) and NIMH.
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.