Project description:Alveolar myofibroblasts emerge during postnatal lung development and are substantially cleared following the completion of the alveolar stage of lung development. In this study, we hypothesized that alveolar myofibroblast descendants that escape apoptotic clearance are reactivated in resposne to injury during adult life.
Project description:We induced differentiation from human induced pluripotent stem cell (hiPSC)-derived alveolar type2 (AT2) cells into hiPSC-derived 2D alveoalr type 1 (2D-iAT1) cells. Single cell RNA sequencing revealed that 2D-iAT1 cells were composed of three clusters.
Project description:Early postnatal myofibroblasts are a key cell type involved in postnatal alveolarization. The majority of these cells undergo apoptosis post-alveolarization. However, some dedifferntaite and persist in the adult lung. We utilized single cell RNA seq. to understand transcriptomics of these persisted myofibroblasts.
Project description:Alveolar formation increases the surface area for gas exchange. A molecular understanding of alveologenesis remains incomplete. Here, we show that the autonomic nerve and alveolar myofibroblast form a functional unit in mice. Myofibroblasts secrete neurotrophins to promote neurite extension/survival, whereas neurotransmitters released from autonomic terminals are necessary for myofibroblast proliferation and migration, a key step in alveologenesis. This establishes a functional link between autonomic innervation and alveolar formation. We also discover that planar cell polarity (PCP) signaling employs a Wnt-Fz/Ror-Vangl cascade to regulate the cytoskeleton and neurotransmitter trafficking/release from the terminals of autonomic nerves. This represents a new aspect of PCP signaling in conferring cellular properties. Together, these studies offer molecular insight into how autonomic activity controls alveolar formation. Our work also illustrates the fundamental principle of how two tissues (e.g., nerves and lungs) interact to build alveoli at the organismal level.
Project description:The mesenchyme consists of heterogeneous cell populations that support neighboring structures and are integral to intercellular signaling. Despite such importance, mesenchymal cell types are poorly defined morphologically and molecularly, lagging behind their counterparts in the epithelial, endothelial, and immune lineages. Leveraging single-cell RNA-seq, three-dimensional imaging, and lineage tracing, we classify the mouse lung mesenchyme into three proximal-distal axes that are associated with the endothelium, epithelium, and interstitium, respectively. From proximal to distal, (1) the vascular axis includes vascular smooth muscle cells and pericytes that transition as arterioles and venules ramify into capillaries; (2) the epithelial axis includes airway smooth muscle cells and two populations of myofibroblasts: ductal myofibroblasts, surrounding alveolar ducts and marked by CDH4, HHIP, and LGR6, which persist post-alveologenesis, and alveolar myofibroblasts, surrounding alveoli and marked by high expression of PDGFRA, which undergo developmental apoptosis; (3) the interstitial axis, residing between the epithelial and vascular trees and sharing a newly-identified marker MEOX2, includes fibroblasts in the bronchovascular bundle and the alveolar interstitium that are marked by IL33 and Wnt2, respectively. Single-cell imaging reveals distinct morphology of each mesenchymal cell population. This classification provides a conceptual and experimental framework applicable to other organs.
Project description:A subset of Cancer-Associated Fibroblasts (CAF-S1) mediates immunosuppression in breast cancers (BC), but its heterogeneity and its impact on immunotherapy response remain unknown. Here, we identify 8 CAF-S1 clusters by analyzing more than 18000 single CAF-S1 fibroblasts from BC. We validate the 5 most abundant clusters by flow cytometry and in silico analyses in other cancer types, highlighting their relevance. Myofibroblasts from clusters 0 and 3, characterized by extra-cellular matrix proteins and TGF signaling respectively, are indicative of primary resistance to immunotherapies. Cluster 0 up-regulates PD-1 and CTLA-4 protein levels in regulatory T lymphocytes (Tregs), which in turn increases CAF-S1 cluster 3 cellular content. Thus, our study highlights a positive feedback loop between specific CAF-S1 clusters and Tregs and uncovers their role in immunotherapy resistance.
Project description:All samples are conditioned media from primary cultured human gastric myofibroblasts, derived from either carcinoma tissue, or adjacent non cancerous tissue. In each experiment the cancer-derived myofibroblasts are compared against the non-cancer derived myofibroblasts from the same patient. All of the experiments were samples from Patient 1, except for 648, which is from Patient 2. SILAC labelling in each case is; 567 - Methionine COFRADIC; Cancer-derived = Heavy, Non-cancer = Light 575 - N-terminal COFRADIC; Cancer-derived = Heavy, Non-cancer = Light 646 - Cancer-derived = Light, Non-cancer = Heavy 647 - Non-cancer = Heavy, Non-cancer = Light (same cell line labelled twice to create a control experiment) 648 - Cancer-derived = Heavy, Non-cancer = Light