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Biology subjects

Noble, P. W.

Publications and source records attributed to Noble, P. W..

5 recordsLinked to original sources

Syndecan-1 Promotes Alveolar Type 2 Epithelial Cell Senescence during Lung Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is an age-related, progressive, and fatal interstitial lung disease for which effective therapies remain limited. Alveolar type 2 (AT2) epithelial cells serve as facultative stem cells essential for alveolar repair; however, AT2 cell senescence disrupts epithelial regeneration and contributes to fibrotic remodeling in IPF. Syndecan-1 is a transmembrane heparan sulfate proteoglycan predominantly expressed by lung epithelial cells, but its role in AT2 dysfunction during fibrosis is poorly defined. Here, we demonstrate that syndecan-1 is robustly upregulated in AT2 cells in IPF and other fibrotic lung diseases, as well as in murine bleomycin-induced lung fibrosis. Syndecan-1 expression was further enhanced with aging and associated with increased fibrotic burden in aged mice. Using integrated human transcriptomic analyses, mouse genetic models, and epithelial cell-based systems, we show that excess syndecan-1 promotes cell-autonomous epithelial senescence and impairs AT2 progenitor function. Elevated syndecan-1 reduced AT2 renewal capacity, disrupted differentiation, and diminished surfactant protein C level, whereas genetic loss of syndecan-1 attenuated senescence and preserved epithelial function following injury. Together, these findings identify syndecan-1 as a critical epithelial regulator of AT2 senescence and maladaptive repair in pulmonary fibrosis and support targeting syndecan-1-driven epithelial dysfunction as a potential therapeutic strategy.

cell biology↗

A transcriptional cell atlas identifies the decline in the AT2 niche in aged human lungs

Aging poses a global public health challenge, associated with molecular and physiological changes in the lungs. It increases susceptibility to acute and chronic lung diseases, yet the underlying molecular and cellular drivers in aged populations are not fully appreciated. To systematically profile the genetic changes associated with age, we present a single-cell transcriptional atlas comprising nearly half a million cells from the healthy lungs of human subjects spanning various ages, sexes, and smoking statuses. Most annotated cell lineages in aged lungs exhibit dysregulated genetic programs. Specifically, the aged alveolar epithelial cells, including both alveolar type II (AT2) and type I (AT1) cells, demonstrate loss of epithelial identities, heightened inflammaging characterized by increased expression of AP-1 transcription factor and chemokine genes, and significantly increased cellular senescence. Furthermore, the aged mesenchymal cells display a remarkable decrease in Collagen and Elastin transcription. The decline of the AT2 niche is further exacerbated by a weakened endothelial cell phenotype and a dysregulated genetic program in macrophages. These findings highlight the dysregulation observed in both AT2 stem cells and their supportive niche cells, potentially contributing to the increased susceptibility of aged populations to lung diseases.

cell biology↗

cGAS-activating lupus autoantibody for cancer immunotherapy

Cytoplasmic DNA triggers a cGAS-mediated signaling cascade that promotes an innate immune response and is potentially actionable in cancer immunotherapy. Here we show that a cytoplasmic-localizing lupus anti-DNA autoantibody activates cGAS and facilitates an immune-mediated prolongation of survival in orthotopic models of glioblastoma (GBM). Mechanistically, cellular penetration and blood-brain barrier crossing by the anti-DNA autoantibody is linked to nucleoside transport. Pulldown, knockdown, signaling, and cytotoxicity assays demonstrate autoantibody association with and activation of cGAS. In orthotopic GBM models, the autoantibody localizes to brain tumor, increases tumor CD8+ T cell content, and prolongs survival in immunocompetent but not immunodeficient mice. This work introduces the new concept of a cGAS-activating anti-DNA autoantibody, which impacts theories on mechanisms of autoimmunity and has translational applications in cancer immunotherapy.

immunology↗

Single-Cell Transcriptomics Identifies Dysregulated Metabolic Programs of Aging Alveolar Progenitor Cells in Lung Fibrosis

Aging is a critical risk factor in progressive lung fibrotic diseases such as idiopathic pulmonary fibrosis (IPF). Loss of integrity of type 2 alveolar epithelial cells (AEC2s) is the main causal event in the pathogenesis of IPF. To systematically examine the genomic program changes of AEC2s with aging and lung injury, we performed unbiased single cell RNA-seq analyses of lung epithelial cells from either uninjured or bleomycin-injured young and old mice. Major lung epithelial cell types were readily identified with canonical cell markers in our dataset. Heterogenecity of AEC2s was apparent, and AEC2s were then classified into three subsets according to their gene signatures. Genes related to lipid metabolism and glycolysis were significantly altered within these three clusters of AEC2s, and also affected by aging and lung injury. Importantly, IPF AEC2s showed similar genomic programming and metabolic changes as that of AEC2s from bleomycin injured old mouse lungs relative to controls. Furthermore, perturbation of both lipid metabolism and glycolysis significantly changed progenitor renewal capacity in 3-Demensional organoid culture of AEC2s. Taken togather, this work identified metabolic defects of AEC2s in aging and during lung injury. Strategies to rectify these altered programs would promote AEC2 renewal which in turn improves lung repair. One sentence summaryMetabolic defects of alveolar progenitors in aging and during lung injury impair their renewal.

cell biology↗

Senescence of alveolar stem cells drives progressive pulmonary fibrosis

Tissue fibrosis is a common pathological outcome of chronic disease that markedly impairs organ function leading to morbidity and mortality. In the lung, idiopathic pulmonary fibrosis (IPF) is an insidious and fatal interstitial lung disease associated with declining pulmonary function. Here, we show that alveolar type 2 (AT2) stem cells isolated from IPF lung tissue exhibit characteristic transcriptomic features of cellular senescence. We used conditional loss of Sin3a in adult mouse AT2 cells to initiate a program of p53-dependent cellular senescence, AT2 cell depletion, and spontaneous, progressive pulmonary fibrosis. We establish that senescence rather than loss of epithelial stem cells serves as a proximal driver of Tgf{beta} activation and progressive fibrosis and show that either genetic or pharmacologic interventions targeting p53 activation, senescence, or downstream Tgf{beta} activation, block fibrogenesis.

cell biology↗