Selected Grantee Publications
SALL1 Enforces Microglia-Specific DNA Binding and Function of SMADs to Establish Microglia Identity
Fixsen et al., Nature Immunology. 2023.
https://doi.org/10.1038/s41590-023-01528-8
Microglia function is thought to play a role in neurodevelopmental, psychiatric, and neurodegenerative diseases. Using knockout mice, investigators explored functional interactions between spalt-like transcription factor 1 (SALL1) and SMAD4, which demonstrated that interactions are mediated by a conserved microglia-specific SALL1 super-enhancer and result in direct activation of regulatory elements. The concerted interactions induce a microglia lineage determining program of gene expression. These findings indicate that expression of SALL1 and associated genes could contribute to phenotypes of aging and neurodegenerative diseases. Supported by ORIP (S10OD026929), NIA, NIMH, and NINDS.
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.
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.
Identification of a Heterogeneous and Dynamic Ciliome during Embryonic Development and Cell Differentiation
Elliott et al., Development. 2023.
Ciliopathies are a class of diseases that arise when the structure or function of the cilium is compromised. To definitively determine the extent of heterogeneity within the ciliome, investigators compared the ciliomes of six distinct embryonic domains. The data comprehensively revealed that about 30% of the ciliome is differentially expressed across analyzed tissues in the developing embryo. Furthermore, upregulation of numerous ciliary genes correlated with osteogenic cell-fate decisions, suggesting that changes in the ciliome contribute to distinct functions of cell types in vertebrate species. Supported by ORIP (UM1OD023222), NIDCR, and NIGMS.
Pembrolizumab and Cabozantinib in Recurrent Metastatic Head and Neck Squamous Cell Carcinoma: A Phase 2 Trial
Saba et al., Nature Medicine. 2023.
https://www.doi.org/10.1038/s41591-023-02275-x
A multicenter clinical trial was conducted in 33 evaluable (36 enrolled) patients with recurrent metastatic head and neck squamous cell carcinoma (RMHNSCC) on a regimen combining cabozantinib, a tyrosine kinase inhibitor, with the standard of care of anti–programmed cell death protein 1 agent pembrolizumab. Results showed that 17 patients (52%) exhibited partial response and 13 (39%) exhibited stable disease, with an overall clinical benefit rate of 91%. Median progression-free survival (PFS) was 14.6 months, and the 1-year PFS was 54%. The pembrolizumab and cabozantinib regimen was well tolerated in patients with RMHNSCC. The promising clinical benefit warrants further investigation. Supported by ORIP (S10OD021644), NCI, and NIDCR.
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.
Production and Characterization of Monoclonal Antibodies to Xenopus Proteins
Horr et al., Development. 2023.
https://pubmed.ncbi.nlm.nih.gov/36789951/
Monoclonal antibodies are powerful and versatile tools that enable the study of proteins in diverse contexts. They are often utilized to assist with identification of subcellular localization and characterization of the function of target proteins of interest. However, because there can be considerable sequence diversity between orthologous proteins in Xenopus and mammals, antibodies produced against mouse or human proteins often do not recognize Xenopus counterparts. To address this issue, the authors refined existing mouse monoclonal antibody production protocols to generate antibodies against Xenopus proteins of interest. Here, they describe several approaches for the generation of useful mouse anti-Xenopus antibodies to multiple Xenopus proteins and their validation in various experimental approaches. Supported by ORIP (R24OD021485, S10OD010645) and NIDCR.
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.