Dillonmcmanus7529

Real-time in vivo imaging provides an essential window into the spatiotemporal cellular events contributing to tissue development and pathology. By coupling longitudinal intravital imaging with genetic lineage tracing, here we capture the earliest cellular events arising in response to active Wnt/β-catenin signaling and the ensuing impact on the organization and differentiation of the mammary epithelium. This enables us to interrogate how Wnt/β-catenin regulates the dynamics of distinct subpopulations of mammary epithelial cells in vivo and in real time. We show that β-catenin stabilization, when targeted to either the mammary luminal or basal epithelial lineage, leads to cellular rearrangements that precipitate the formation of hyperplastic lesions that undergo squamous transdifferentiation. These results enhance our understanding of the earliest stages of hyperplastic lesion formation in vivo and reveal that, in mammary neoplastic development, β-catenin activation dictates a hair follicle/epidermal differentiation program independently of the targeted cell of origin.Diet is a key regulator of metabolism and interacts with the intestinal microbiome. Here, we study the role of the Drosophila intestinal stem cell (ISC)-specific biotin transporter Smvt in midgut homeostasis, infection-induced regeneration, and tumorigenesis. We show that Smvt-transported biotin in ISCs is necessary for ISC mitosis. Smvt deficiency impairs intestinal maintenance, which can be rescued by the human Smvt, encoded by SLC5A6. ISC-specific, Smvt-silenced flies exhibit microbial dysbiosis, whereby the growth of Providencia sneebia, an opportunistic pathogen, is favored. Dysbiosis correlates with increased Nox expression, reactive oxygen species (ROS), and enterocyte apoptosis. Flies acquire biotin from their diet and microbiota. We show that, when dietary biotin is scarce, biotin-producing commensals, e.g., E. coli, can rescue reduced ISC mitosis. Smvt and commensals also control intestinal tumor growth. Our findings suggest that direct modification of the gut microbiome by biotin can serve as an approach for the treatment of dysbiosis-promoted diseases and tumorigenesis control.Immune checkpoint inhibitor (ICI) therapy is generating remarkable responses in individuals with cancer, but only a small portion of individuals with breast cancer respond well. Here we report that tumor-derived Jagged1 is a key regulator of the tumor immune microenvironment. Jagged1 promotes tumorigenesis in multiple spontaneous mammary tumor models. Through Jagged1-induced Notch activation, tumor cells increase expression and secretion of multiple cytokines to help recruit macrophages into the tumor microenvironment. Educated macrophages crosstalk with tumor-infiltrating T cells to inhibit T cell proliferation and tumoricidal activity. In individuals with triple-negative breast cancer, a high expression level of Jagged1 correlates with increased macrophage infiltration and decreased T cell activity. read more Co-administration of an ICI PD-1 antibody with a Notch inhibitor significantly inhibits tumor growth in breast cancer models. Our findings establish a distinct signaling cascade by which Jagged1 promotes adaptive immune evasion of tumor cells and provide several possible therapeutic targets.How metastatic cells arise is unclear. Here, we search for the induction of recently characterized pro-metastatic states as a surrogate for the origin of metastasis. Since cell-death-inducing therapies can paradoxically promote metastasis, we ask if such treatments induce pro-metastatic states in human colon cancer cells. We find that post-near-death cells acquire pro-metastatic states (PAMEs) and form distant metastases in vivo. These PAME ("let's go" in Greek) cells exhibit a multifactorial cytokine storm as well as signs of enhanced endoplasmic reticulum (ER) stress and nuclear reprogramming, requiring CXCL8, INSL4, IL32, PERK-CHOP, and NANOG. PAMEs induce neighboring tumor cells to become PAME-induced migratory cells (PIMs) highly migratory cells that re-enact the storm and enhance PAME migration. Metastases are thus proposed to originate from the induction of pro-metastatic states through intrinsic and extrinsic cues in a pro-metastatic tumoral ecosystem, driven by an impending cell-death experience involving ER stress modulation, metastatic reprogramming, and paracrine recruitment via a cytokine storm.Epstein-Barr virus (EBV) persistently infects people worldwide. Delivery of ∼170-kb EBV genomes to nuclei and use of nuclear membrane-less replication compartments (RCs) for their lytic cycle amplification necessitate evasion of intrinsic antiviral responses. Proteomics analysis indicates that, upon B cell infection or lytic reactivation, EBV depletes the cohesin SMC5/6, which has major roles in chromosome maintenance and DNA damage repair. The major tegument protein BNRF1 targets SMC5/6 complexes by a ubiquitin proteasome pathway dependent on calpain proteolysis and Cullin-7. In the absence of BNRF1, SMC5/6 associates with R-loop structures, including at the viral lytic origin of replication, and interferes with RC formation and encapsidation. CRISPR analysis identifies RC restriction roles of SMC5/6 components involved in DNA entrapment and SUMOylation. Our study highlights SMC5/6 as an intrinsic immune sensor and restriction factor for a human herpesvirus RC and has implications for the pathogenesis of EBV-associated cancers.Hepatitis B virus (HBV) is a global pathogen. We report here that the cellular CRM1 machinery can mediate nuclear export of entire HBV core (HBc) particles containing encapsidated viral RNAs. Two CRM1-mediated nuclear export signals (NESCRM1) cluster at the conformationally flexible spike tips of HBc particles. Mutant NESCRM1 capsids exhibit strongly reduced associations with CRM1 and nucleoporin358 in vivo. CRM1 and NXF1 machineries mediate nuclear export of HBc particles independently. Inhibition of nuclear export has pleiotropic consequences, including nuclear accumulation of HBc particles, a significant reduction of encapsidated viral RNAs in the cytoplasm but not in the nucleus, and barely detectable viral DNA. We hypothesize an HBV life cycle where encapsidation of the RNA pregenome can initiate early in the nucleus, whereas DNA genome maturation occurs mainly in the cytoplasm. We identified a druggable target for HBV by blocking its intracellular trafficking.Myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) play critical roles in tumorigenesis. However, the mechanisms underlying MDSC and TAM development and function remain unclear. In this study, we find that myeloid-specific activation of Notch/RBP-J signaling downregulates lactate transporter MCT2 transcription via its downstream molecule Hes1, leading to reduced intracellular lactate levels, blunted granulocytic MDSC (G-MDSC) differentiation, and enhanced TAM maturation. We identify c-Jun as a novel intracellular sensor of lactate in myeloid cells using liquid-chromatography-mass spectrometry (LC-MS) followed by CRISPR-Cas9-mediated gene disruption. Meanwhile, lactate interacts with c-Jun to protect from FBW7 ubiquitin-ligase-mediated degradation. Activation of Notch signaling and blockade of lactate import repress tumor progression by remodeling myeloid development. Consistently, the relationship between the Notch-MCT2/lactate-c-Jun axis in myeloid cells and tumorigenesis is also confirmed in clinical lung cancer biopsies. Taken together, our current study shows that lactate metabolism regulated by activated Notch signaling might participate in MDSC differentiation and TAM maturation.Type I interferons (IFN-I) are essential to establish antiviral innate immunity. Unanchored (or free) polyubiquitin (poly-Ub) has been shown to regulate IFN-I responses. However, few unanchored poly-Ub interactors are known. To identify factors regulated by unanchored poly-Ub in a physiological setting, we developed an approach to isolate unanchored poly-Ub from lung tissue. We identified the RNA helicase DHX16 as a potential pattern recognition receptor (PRR). Silencing of DHX16 in cells and in vivo diminished IFN-I responses against influenza virus. These effects extended to members of other virus families, including Zika and SARS-CoV-2. DHX16-dependent IFN-I production requires RIG-I and unanchored K48-poly-Ub synthesized by the E3-Ub ligase TRIM6. DHX16 recognizes a signal in influenza RNA segments that undergo splicing and requires its RNA helicase motif for direct, high-affinity interactions with specific viral RNAs. Our study establishes DHX16 as a PRR that partners with RIG-I for optimal activation of antiviral immunity requiring unanchored poly-Ub.The mechanisms by which astrocytes modulate neural homeostasis, synaptic plasticity, and memory are still poorly explored. Astrocytes form large intercellular networks by gap junction coupling, mainly composed of two gap junction channel proteins, connexin 30 (Cx30) and connexin 43 (Cx43). To circumvent developmental perturbations and to test whether astrocytic gap junction coupling is required for hippocampal neural circuit function and behavior, we generate and study inducible, astrocyte-specific Cx30 and Cx43 double knockouts. Surprisingly, disrupting astrocytic coupling in adult mice results in broad activation of astrocytes and microglia, without obvious signs of pathology. We show that hippocampal CA1 neuron excitability, excitatory synaptic transmission, and long-term potentiation are significantly affected. Moreover, behavioral inspection reveals deficits in sensorimotor performance and a complete lack of spatial learning and memory. Together, our findings establish that astrocytic connexins and an intact astroglial network in the adult brain are vital for neural homeostasis, plasticity, and spatial cognition.Despite their importance in tissue homeostasis and renewal, human pituitary stem cells (PSCs) are incompletely characterized. We describe a human single nucleus RNA-seq and ATAC-seq resource from pediatric, adult, and aged postmortem pituitaries (snpituitaryatlas.princeton.edu) and characterize cell-type-specific gene expression and chromatin accessibility programs for all major pituitary cell lineages. We identify uncommitted PSCs, committing progenitor cells, and sex differences. Pseudotime trajectory analysis indicates that early-life PSCs are distinct from the other age groups. Linear modeling of same-cell multiome data identifies regulatory domain accessibility sites and transcription factors that are significantly associated with gene expression in PSCs compared with other cell types and within PSCs. We identify distinct deterministic mechanisms that contribute to heterogeneous marker expression within PSCs. These findings characterize human stem cell lineages and reveal diverse mechanisms regulating key PSC genes and cell type identity.The 12-h clock coordinates lipid homeostasis, energy metabolism, and stress rhythms via the transcriptional regulator XBP1. However, the biochemical and physiological bases for integrated control of the 12-h clock and diverse metabolic pathways remain unclear. Here, we show that steroid receptor coactivator SRC-3 coactivates XBP1 transcription and regulates hepatic 12-h cistrome and gene rhythmicity. Mice lacking SRC-3 show abnormal 12-h rhythms in hepatic transcription, metabolic functions, systemic energetics, and rate-limiting lipid metabolic processes, including triglyceride, phospholipid, and cardiolipin pathways. Notably, 12-h clock coactivation is not only preserved, with its cistromic activation priming ahead of the zeitgeber cue of light, but concomitant with rhythmic remodeling in the absence of food. These findings reveal that SRC-3 integrates the mammalian 12-h clock, energy metabolism, and membrane and lipid homeostasis and demonstrates a role for the 12-h clock machinery as an active transcriptional mechanism in anticipating physiological and metabolic energy needs and stresses.