The rockefeller university

Brain metastasis is a common and devastating complication of cancer that affects over 50% of HER2-positive (HER2+) breast cancer patients. The lack of effective long-term treatment options for brain metastasis significantly increases morbidity and mortality among these patients. Therefore, understanding the underlying mechanisms that drive brain metastasis is critically important for developing new strategies to treat it effectively. Genetically engineered mouse models (GEMMs) of HER2+ breast cancer have been instrumental in understanding the development and progression of HER2+ breast cancer. However, the GEMM models for HER2+ breast cancer do not develop brain metastasis and are not suitable for the study of brain metastasis. We therefore developed a fully immunocompetent mouse model of experimental brain metastasis in HER2+ breast cancer by injecting a murine HER2/neu-expressing mammary-tumor-cell line into the arterial circulation of syngeneic FVB/N mice followed by isolation of brain-metastatic derivatives through in-vivo selection. By this in-vivo serial passaging process, we selected highly brain-metastatic (BrM) derivatives known as neu-BrM. Notably, after intracardiac injection, neu-BrM cells generated brain metastasis in 100% of the mice, allowing us to study the later stages of metastatic progression, including cancer-cell extravasation and outgrowth in the brain. Analogous to human brain metastasis, we observed reactive gliosis and significant immune infiltration in the brain tissue of mice injected with neu-BrM cells. We further confirmed that brain-metastatic lesions in the neu-BrM model express HER2. Consistently, we found that the brain-metastatic burden in these mice can be significantly reduced but not eliminated with tucatinib, an FDA-approved, blood-brain-barrier-penetrant HER2 inhibitor. Therefore, the neu-BrM HER2+ breast cancer model can be used to investigate the roles of innate and adaptive immune-system components during brain-metastatic progression and the mechanisms of HER2-therapy response and resistance.

The ability of proteins involved in eukaryotic DNA replication to overcome obstacles - such as protein and DNA 'roadblocks' - is critical for ensuring faithful genome duplication. G-quadruplexes are higher-order nucleic acid structures that form in guanine-rich regions of DNA and have been shown to act as obstacles, interfering with genomic maintenance pathways. This study introduces a real-time, fluorescence microscopy-based method to observe DNA polymerase interactions with G-quadruplex structures. Short, primed DNA oligonucleotides containing a Gquadruplex were immobilized on functionalized glass coverslips within a microfluidic flow cell. Fluorescently labeled DNA polymerases were introduced, allowing their behavior and stoichiometry to be monitored over time. This approach enabled the observation of polymerase behavior as it was stalled by a G-quadruplex. Specifically, using fluorescently labeled yeast polymerase delta, it was found that upon encountering a G-quadruplex, the polymerase undergoes a continuous cycle of binding and unbinding. This single-molecule assay can be adapted to study interactions between various DNA-maintenance proteins and obstacles on the DNA substrate.

Accurately predicting species' responses to anthropogenic climate change is hampered by limited knowledge of their spatiotemporal ecological and evolutionary dynamics. We combine landscape genomics, demographic reconstructions, and species distribution models to assess the eco-evolutionary responses to past climate fluctuations and to future climate of an Afro-Palaearctic migratory raptor, the lesser kestrel (Falco naumanni). We uncover two evolutionarily and ecologically distinct lineages (European and Asian), whose demographic history, evolutionary divergence, and historical distribution range were profoundly shaped by past climatic fluctuations. Using future climate projections, we find that the Asian lineage is at higher risk of range contraction, increased migration distance, climate maladaptation, and consequently greater extinction risk than the European lineage. Our results emphasise the importance of providing historical context as a baseline for understanding species' responses to contemporary climate change, and illustrate how incorporating intraspecific genetic variation improves the ecological realism of climate change vulnerability assessments.

BACKGROUND. Natural resistance to Mycobacterium tuberculosis (Mtb) infection in some people with HIV (PWH) is unexplained. METHODS. We performed single cell RNA-sequencing of bronchoalveolar lavage cells, unstimulated or exvivo stimulated with Mtb, for 7 PWH who were tuberculin skin test (TST) and IFN-gamma release assay (IGRA) positive (called LTBI) and 6 who were persistently TST and IGRA negative (called resisters). RESULTS. Alveolar macrophages (AM) from resisters displayed a baseline M1 macrophage phenotype while AM from LTBI did not. Resisters displayed alveolar lymphocytosis, with enrichment of all T cell subpopulations including IFNG-expressing cells. In both groups, mycobactericidal granulysin was expressed almost exclusively by a T cell subtype that coexpressed granzyme B, perforin and NK cell receptors. These poly-cytotoxic T lymphocytes (poly-CTL) overexpressed activating NK cell receptors and were increased in resister BAL. Following challenge with Mtb, only intraepithelial lymphocyte-like cells from LTBI participants responded with increased transcription of IFNG. AM from resisters responded with a stronger TNF signature at 6 hours after infection while at 24 hours after infection, AM from LTBI displayed a stronger IFN-gamma signature. Conversely, at 24 hours after infection, only AM from resisters displayed an upregulation of MHC class I polypeptide-related sequence A (MICA) transcripts, which encode an activating ligand for poly-CTL. CONCLUSION. These results suggest that poly-CTL and M1-like pre-activated AM mediate the resister phenotype in PWH. FUNDING. National Institutes of Health. Canadian Institutes of Health Research. Digital Research Alliance of Canada. French National Research Agency. French National Agency for Research on AIDS and Viral Hepatitis. St. Giles Foundation. General Atlantic Foundation. South African Medical Research Council Centre forTuberculosis Research.

Diabetes is a major risk factor for cardiovascular disease, but the molecular mechanisms underlying diabetic vasculopathy have been elusive. Here we report that inositol hexakisphosphate kinase 1 (IP6K1) mediates hyperglycemia-induced endothelial senescence by rewiring liver kinase B1 (LKB1) signaling from the AMPK pathway to the p53 pathway. We found that hyperglycemia upregulated IP6K1, which disrupted Hsp/Hsc70 and carboxyl terminus of Hsc70-interacting protein-mediated LKB1 degradation, leading to increased expression levels of LKB1. High glucose also strengthened the binding of IP6K1 to AMPK, suppressing LKB1-mediated AMPK activation. Thus, elevated LKB1 did not lead to activation of the AMPK pathway. Instead, it bound more to p53, resulting in p53-dependent endothelial senescence. Endothelial cell-specific deletion of IP6K1 alleviated, whereas endothelial cell-specific overexpression of IP6K1 exaggerated, hyperglycemia-induced endothelial senescence. This study reveals a regulatory mechanism of IP6K1 in switching LKB1 activation of the AMPK pathway to activation of the p53 pathway. IP6K1 represents a potential therapeutic target for treating hyperglycemia-induced endothelial dysfunction.Article Highlights Diabetes is a major risk factor for cardiovascular diseases. The mechanisms of hyperglycemia-induced endothelial dysfunction have been elusive. We found that inositol hexakisphosphate kinase 1 (IP6K1) mediates hyperglycemia-induced endothelial senescence by switching liver kinase B1 (LKB1) activation of the AMPK pathway to activation of the p53 pathway. Hyperglycemia upregulates IP6K1, which stabilizes LKB1 by disrupting Hsp/Hsc70 and carboxyl terminus of Hsc70-interacting protein-mediated LKB1 degradation but suppresses LKB1-dependent AMPK activation. Elevated LKB1 binds more to p53, resulting in p53-dependent endothelial senescence. Endothelial cell-specific deletion of IP6K1 attenuates, whereas endothelial cell-specific overexpression of IP6K1 exaggerates, hyperglycemia-induced endothelial senescence.

Langerhans cell histiocytosis (LCH) and Erdheim-Chester disease (ECD) are clonal myeloid disorders associated with mitogen-activated protein (MAP)-kinase-activating mutations and an increased risk of neurodegeneration. We found microglial mutant clones in LCH and ECD patients, whether or not they presented with clinical symptoms of neurodegeneration, associated with microgliosis, astrocytosis, and neuronal loss, predominantly in the rhombencephalon gray nuclei. Neurological symptoms were associated with PU.1+ clone size (p = 0.0003) in patients with the longest evolution of the disease, indicating a phase of subclinical incipient neurodegeneration. Genetic barcoding analysis suggests that clones may originate from definitive or yolk sac hematopoiesis, depending on the patients. In a mouse model, disease topography was attributable to a local clonal proliferative advantage, and microglia depletion by a CSF1R-inhibitor limited neuronal loss and improved survival. These studies characterize a neurodegenerative disease associated with clonal proliferation of inflammatory microglia. The long preclinical stage represents a therapeutic window before irreversible neuronal depletion.

We review key measurements performed by CMS in the context of its heavy ion physics program, using event samples collected in 2010-2018 with several collision systems and energies. These studies provide detailed macroscopic and microscopic probes of the quark-gluon plasma (QGP) created at the LHC energies, a medium characterized by the highest temperature and smallest baryon-chemical potential ever reached in the laboratory. Numerous observables related to high-density quantum chromodynamics (QCD) were studied, leading to some of the most impactful and qualitatively novel results in the 40-year history of the field. Using a dedicated high-multiplicity trigger in the first pp run, CMS discovered that small collision systems can exhibit signs of collectivity, a generic phenomenon with significant implications and presently understood to affect essentially all soft physics processes. This observation opened new paths to understand how fluidity and plasma properties emerge in QCD matter as a function of system size. Measurements of jet quenching have reached a completely new level of detail by directly assessing, for the first time, the medium modification of parton showers, as opposed to simply observing leading hadrons or di-hadrons. The first fully reconstructed beauty hadron and heavy-flavor jet nuclear modifications were also measured. The large size of the event samples, the precision of the measurements, and the extension of the probed kinematical phase space, allowed many other hard probes of the QGP medium to be explored in detail, leading to multiple groundbreaking findings. In particular, the seminal measurements of bottomonium suppression patterns answer fundamental questions that have been actively pursued, both theoretically and experimentally, by the community since the mid-1980s. We conclude by outlining the opportunities offered by the continuation of this physics program at the LHC. (c) 2024 CERN for the benefit of the CMS Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Wang et al. recently reported that during helminth infection, innate lymphoid cell (ILC)-derived IL-13 is sensed by gut neurons, which in turn secretes CGRP to inhibit ILC2 proliferation and anti-helminth responses. Hence, this study demonstrates a bidirectional crosstalk between enteric neurons and immune cells that regulates type-2 immunity.

Apolipoprotein E (APOE) has multiple functions in metabolism and immunoregulation. Its common germ line variants APOE2, APOE3, and APOE4 give rise to 3 functionally distinct gene products. Previous studies reported yin-yang roles of APOE2 and APOE4 in immunological processes, but their effects in hematopoietic stem cell transplantation (HSCT) have never been studied. We performed APOE genotyping in 2 contemporary cohorts of 348 and 447 patients with acute myeloid leukemia who had received allogeneic HSCT and evaluated the associations of recipient and donor APOE genetic variations with posttransplant outcomes. Patients who carried at least 1 APOE2 allele had a higher risk of posttransplant death than APOE4 carriers in the discovery (hazard ratio [HR], 2.09; P = .024) and validation cohorts (HR, 1.96; P = .040). Detrimental APOE2 effects were driven by an increased risk of severe chronic graft-versus-host disease (GVHD; adjusted HR [HRadj], 1.85; P = .034) and nonrelapse death (HRadj, 1.72; P = .044). In non-APOE2 recipients, transplantation of an APOE2-positive allograft was associated with an increased incidence of grade 3 to 4 acute GVHD (HRadj, 2.82; P = .012) and severe chronic GVHD (HRadj, 2.54; P = .022) compared with APOE2-negative grafts. In summary, the APOE2 allele, typically considered a longevity gene in the general population, was associated with a higher risk of acute GVHD (HRadj, 2.75; P = .002), chronic GVHD (HRadj, 2.57; P = .001), and posttransplant mortality (HRadj, 1.79; P = .004), when present in either the host or transplanted from the donor.