Selected Grantee Publications
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Tumor Explants Elucidate a Cascade of Paracrine SHH, WNT, and VEGF Signals Driving Pancreatic Cancer Angiosuppression
Hasselluhn et al., Cancer Discovery. 2024.
https://pubmed.ncbi.nlm.nih.gov/37966260/
This study presents a key mechanism that prevents pancreatic ductal adenocarcinoma (PDAC) from undergoing neoangiogenesis, which affects its development, pathophysiology, metabolism, and treatment response. Using human and murine PDAC explants, which effectively retain the complex cellular interactions of native tumor tissues, and single-cell regulatory network analysis, the study identified a cascade of three paracrine pathways bridging between multiple cell types and acting sequentially, Hedgehog to WNT to VEGF, as a key suppressor of angiogenesis in KRAS-mutant PDAC cells. This study provides an experimental paradigm for dissecting higher-order cellular interactions in tissues and has implications for PDAC treatment strategies. Supported by ORIP (S10OD012351, S10OD021764), NCI, and NIDDK.
Epigenetic MLH1 Silencing Concurs With Mismatch Repair Deficiency in Sporadic, Naturally Occurring Colorectal Cancer in Rhesus Macaques
Deycmar et al., Journal of Translational Medicine. 2024.
https://pubmed.ncbi.nlm.nih.gov/38504345
Rhesus macaques serve as a useful model for colorectal cancer (CRC) in humans, but more data are needed to understand the molecular pathogenesis of these cancers. Using male and female rhesus macaques, researchers investigated mismatch repair status, microsatellite instability, genetic mutations, transcriptional differences, and epigenetic alterations associated with CRC. Their data indicate that epigenetic silencing suppresses MLH1 transcription, induces the loss of MLH1 protein, abrogates mismatch repair, and drives genomic instability in naturally occurring CRC in rhesus macaques. This work provides a uniquely informative model for human CRC. Supported by ORIP (P51OD011092, R24OD010947, R24OD021324, P40OD012217, U42OD010426, T35OD010946, T32OD010957), NCATS, and NCI.
De Novo Variants in FRYL Are Associated With Developmental Delay, Intellectual Disability, and Dysmorphic Features
Pan et al., The American Journal of Human Genetics. 2024.
https://www.cell.com/ajhg/fulltext/S0002-9297(24)00039-9
FRY-like transcription coactivator (FRYL) belongs to a Furry protein family that is evolutionarily conserved from yeast to humans, and its functions in mammals are largely unknown. Investigators report 13 individuals who have de novo heterozygous variants in FRYL and one individual with a heterozygous FRYL variant that is not confirmed to be de novo. The individuals present with developmental delay; intellectual disability; dysmorphic features; and other congenital anomalies in cardiovascular, skeletal, gastrointestinal, renal, and urogenital systems. Using fruit flies, investigators provide evidence that haploinsufficiency in FRYL likely underlies a disorder in humans with developmental and neurological symptoms. Supported by ORIP (U54OD030165), NHLBI, NICHD, and NCATS.
Molecular Basis of Human Trace Amine-Associated Receptor 1 Activation
Zilberg et al., Nature Communications. 2024.
https://www.nature.com/articles/s41467-023-44601-4
The authors reported the cryogenic electron microscopy structure of human trace amine-associated receptor 1 (hTAAR1, hTA1) signaling complex, a key modulator in monoaminergic neurotransmission, as well as its similarities and differences with other TAAR members and rodent TA1 receptors. This discovery has elucidated hTA1’s molecular mechanisms underlining the strongly divergent pharmacological properties of human and rodent TA1 and therefore will boost the translation of preclinical studies to clinical applications in treating disorders of dopaminergic dysfunction, metabolic disorders, cognitive impairment, and sleep-related dysfunction. Supported by ORIP (S10OD019994, S10OD026880, and S10OD030463), NIDA, NIGMS, NIMH, and NCATS.
Broad Receptor Tropism and Immunogenicity of a Clade 3 Sarbecovirus
Lee et al., Cell Host and Microbe. 2023.
https://www.sciencedirect.com/science/article/pii/S1931312823004225
Investigators showed that the S glycoprotein of the clade 3 sarbecovirus PRD-0038 in the African Rhinolophus bat has a broad angiotensin-converting enzyme 2 (ACE2) usage and that receptor-binding domain (RBD) mutations further expand receptor promiscuity and enable human ACE2 utilization. They generated a cryogenic electron microscopy structure of the RBD bound to ACE2, explaining receptor tropism and highlighting differences between SARS-CoV-1 and SARS-CoV-2. PRD‑0038 S vaccination elicits greater titers of antibodies cross-reacting with vaccine-mismatched clade 2 and clade 1a sarbecoviruses, compared with SARS-CoV-2. These findings underline a potential molecular pathway for zoonotic spillover of a clade 3 sarbecovirus, as well as the need to develop pan-sarbecovirus vaccines and countermeasures. Supported by ORIP (S10OD032290, S10OD026959, S10OD021644), NIAID, NCI, and NIGMS.
First-in-Human ImmunoPET Imaging of COVID-19 Convalescent Patients Using Dynamic Total-Body PET and a CD8-Targeted Minibody
Omidvari et al., Science Advances. 2023.
https://pubmed.ncbi.nlm.nih.gov/36993568/
Developing noninvasive methods for in vivo quantification of T cell distribution and kinetics is important because most T cells reside in the tissue. Investigators presented the first use of dynamic positron emission tomography (PET) and kinetic modeling for in vivo measurement of CD8+ T cell distribution in healthy individuals and COVID-19 patients. Kinetic modeling results aligned with the expected T cell trafficking effects. Tissue-to-blood ratios were consistent with modeled net influx rates and flow cytometry analysis. These results provide a promising platform for using dynamic PET to study the total-body immune response and memory. Supported by ORIP (S10OD018223) and NCI.
Using Mass Spectrometry Imaging to Map Fluxes Quantitatively in the Tumor Ecosystem
Schwaiger-Haber et al., Nature Communications. 2023.
https://pubmed.ncbi.nlm.nih.gov/37208361/
Mass spectrometry imaging (MSI) can be used to identify metabolic patterns within different microenvironments of tumors but has not been fully integrated into metabolomics workflows. Investigators developed an integrated approach by combining MSI, stable isotope labeling, and a spatial variant of Isotopologue Spectral Analysis to study metabolic pathways across the brains of mice harboring GL261 glioma, a mouse model for glioblastoma. This study reveals the importance of multiple anabolic pathways, including fatty acid elongation flux, in glioma. Supported by ORIP (R24OD024624).
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.
In Vivo MRI Is Sensitive to Remyelination in a Nonhuman Primate Model of Multiple Sclerosis
Donadieu et al., eLife. 2023.
https://pubmed.ncbi.nlm.nih.gov/37083540/
Experimental autoimmune encephalomyelitis (EAE) in the common marmoset is a model for studying inflammatory demyelination in multiple sclerosis (MS). Researchers investigated the feasibility and sensitivity of magnetic resonance imaging (MRI) in characterizing remyelination, a crucial step to recover from MS. Investigators demonstrated that multisequence 7T MRI could detect spontaneous remyelination in marmoset EAE at high statistical sensitivity and specificity in vivo. This study suggests that in vivo MRI can be used for preclinical testing of therapeutic remyelinating agents for MS. Supported by ORIP (R21OD030163) and NINDS.
An E1–E2 Fusion Protein Primes Antiviral Immune Signaling in Bacteria
Ledvina et al., Nature. 2023.
https://www.nature.com/articles/s41586-022-05647-4
Investigators show that the cGAS/DncV–like nucleotidyltransferase (CD‑NTase)–associated protein 2 (Cap2) primes bacterial CD-NTases for activation through a ubiquitin transferase–like mechanism. A cryo-electron microscopy structure of the Cap2-CD-NTase complex reveals Cap2 as an all-in-one ubiquitin transferase–like protein, with distinct domains resembling eukaryotic E1 and E2 proteins. The structure captures a reactive-intermediate state with the CD-NTase C terminus positioned in the Cap2 E1 active site and conjugated to AMP. Cap2 conjugates the CD-NTase C terminus to a target molecule that primes the CD-NTase for increased cGAMP production. The investigators further demonstrate bacteria control immune signaling using an ancient, minimized ubiquitin transferase–like system and provide insight into the evolution of the E1 and E2 machinery across domains of life. Supported by ORIP (S10OD023498, S10OD021527, S10OD025267) and NIGMS.