Selected Grantee Publications
Phytochemical Compound PB125 Attenuates Skeletal Muscle Mitochondrial Dysfunction and Impaired Proteostasis in a Model of Musculoskeletal Decline
Musci et al., Journal of Physiology. 2023.
https://physoc.onlinelibrary.wiley.com/doi/10.1113/JP282273
Age-related musculoskeletal decline contributes to disability and cardiometabolic diseases and is linked to impaired mitochondrial function and disrupted proteostasis. Using male and female Hartley guinea pigs, investigators tested a purported phytochemical activator of nuclear factor erythroid 2-related factor 2, which helps promote redox homeostasis, proteome maintenance, and mitochondrial energetics. They reported that the activator, PB125, improved mitochondrial respiration and attenuated disease- and age-related declines in skeletal muscle protein synthesis. This study provides insights for the development of interventions in humans. Supported by ORIP (T32OD010437) and NIA.
p38MAPKα Stromal Reprogramming Sensitizes Metastatic Breast Cancer to Immunotherapy
Faget et al., Cancer Discovery. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10238649/
This study emphasizes the importance of the metastatic tumor microenvironment in metastatic breast cancer growth and the identification of effective antimetastatic therapies. Using a stromal labeling approach and single-cell RNA sequencing, the authors showed that a combination of p38MAPK inhibition (p38i) and anti-OX40 synergistically reduced metastatic tumor growth and increased overall survival. Further engagement of cytotoxic T cells cured all metastatic disease in mice and produced durable immunologic memory. The Cancer Genome Atlas data analysis revealed that patients with p38i metastatic stromal signature and a high tumor mutational burden (TMB) had increased overall survival. These findings suggest that patients with high TMB would benefit the most from the p38i plus anti-OX40 approach. Supported by ORIP (S10OD028483), NIA, NCI, and NIGMS.
Lymph-Node-Based CD3+ CD20+ Cells Emerge From Membrane Exchange Between T Follicular Helper Cells and B Cells and Increase Their Frequency Following Simian Immunodeficiency Virus Infection
Samer et al., Journal of Virology. 2023.
https://www.doi.org/10.1128/jvi.01760-22
CD4+ T follicular helper cells are known to persist during antiretroviral therapy (ART) and have been identified as key targets for viral replication and persistence. Researchers identified a lymphocyte population that expresses CD3 (i.e., T cell lineage marker) and CD20 (i.e., B cell lineage marker) on the cellular surface in lymphoid tissues from rhesus macaques of both sexes and humans of male and female sexes. In macaques, the cells increased following simian immunodeficiency virus infection, were reduced with ART, and increased in frequency after ART interruption. These cells represent a potential area for future therapeutic strategies. Supported by ORIP (P51OD011132, U42OD011023), NIAID, NCI, NIDDK, NIDA, NHLBI, and NINDS.
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.
CD8+ T Cells Promote HIV Latency by Remodeling CD4+ T Cell Metabolism to Enhance Their Survival, Quiescence, and Stemness
Mutascio et al., Immunity. 2023.
https://www.doi.org/10.1016/j.immuni.2023.03.010
An HIV reservoir persists following antiretroviral therapy, representing the main barrier to an HIV cure. Using a validated in vitro model, investigators explored the mechanism by which CD8+ T cells promote HIV latency and inhibit latency reversal in HIV-infected CD4+ T cells. They reported that CD8+ T cells favor the establishment of HIV latency by modulating metabolic, stemness, and survival pathways that correlate with the downregulation of HIV expression and promote HIV latency. In future studies, comparative analyses may provide insight into common molecular mechanisms in the silencing of HIV expression by CD8+ T cells and macrophages, which can be applied to new intervention strategies that target the HIV reservoir. Supported by ORIP (P51OD011132, S10OD026799), NIAID, NIDDK, NIDA, NHLBI, and NINDS.
Cannabinoid Enhancement of lncRNA MMP25-AS1/MMP25 Interaction Reduces Neutrophil Infiltration and Intestinal Epithelial Injury in HIV/SIV Infection
Premadasa et al., Journal of Clinical Investigation Insight. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10132162/
Gastrointestinal CD4+ T cell depletion during acute simian immunodeficiency virus (SIV) and HIV infection causes significant structural and functional damage, disrupting intestinal immune homeostasis and leading to intestinal epithelial barrier dysfunction. Oral phytocannabinoids are safe and well tolerated in people with HIV, but more information is needed regarding the effects of long-term tetrahydrocannabinol (THC) use on the intestinal epithelial compartment. Investigators profiled gene expression in the colonic epithelium of SIV-infected rhesus macaques of both sexes that were administered THC. They reported that low-dose THC can reduce neutrophil infiltration and intestinal epithelial injury, potentially by downregulating MMP25 expression through modulation of a long noncoding RNA, MMP25-AS1. Supported by ORIP (P51OD011104, P51OD011103), NIAID, and NIDA.
Longitudinal Characterization of Circulating Extracellular Vesicles and Small RNA During Simian Immunodeficiency Virus Infection and Antiretroviral Therapy
Huang et al., AIDS. 2023.
https://www.doi.org/10.1097/QAD.0000000000003487
Antiretroviral therapy is effective for controlling HIV infection but does not fully prevent early aging disorders or serious non-AIDS events among people with HIV. Using pigtail and rhesus macaques (sex not specified), researchers profiled extracellular vesicle small RNAs during different phases of simian immunodeficiency virus infection to explore the potential relationship between extracellular vesicle–associated small RNAs and the infection process. They reported that average particle counts correlated with infection, but the trend could not be explained fully by virions. These findings raise new questions about the distribution of extracellular vesicle RNAs in HIV latent infection. Supported by ORIP (U42OD013117), NIDA, NIMH, NIAID, NCI, and NINDS.
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.
Cannabinoids Modulate the Microbiota–Gut–Brain Axis in HIV/SIV Infection by Reducing Neuroinflammation and Dysbiosis while Concurrently Elevating Endocannabinoid and Indole-3-Propionate Levels
McDew-White et al., Journal of Neuroinflammation. 2023.
https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-023-02729-6
Chronic neuroinflammation is thought to be a significant contributor to HIV-associated neurocognitive disorders. Using rhesus macaques of both sexes, researchers investigated the effects of simian immunodeficiency virus (SIV) infection on the microbiota–gut–brain axis (MGBA), as well as the use of low-dose cannabinoids to reverse MGBA dysregulation. They reported that tetrahydrocannabinol reduced neuroinflammation and dysbiosis and increased plasma endocannabinoid, endocannabinoid-like, glycerophospholipid, and indole-3-propionate levels. This study offers a potential strategy to promote brain health in people with HIV. Supported by ORIP (P51OD011104, P51OD011103), NIAID, and NIDA.
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.