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Chow, Y.-H.

Publications and source records attributed to Chow, Y.-H..

2 recordsLinked to original sources

Dynamics of bleomycin-induced lung injury at single-nucleus resolution

Single-cell RNA sequencing (scRNA-seq) has emerged as a powerful tool for studying individual cell populations in complex tissues during injury and repair. However, it involves extensive sample manipulation, limiting its application in rare and difficult-to-dissociate cell populations. Single-nucleus RNA sequencing (snRNA-seq) bypasses several of these challenges, but its performance in lung disease models is not well characterized. In a longitudinal murine model of bleomycin-induced lung injury, we performed whole lung snRNA-seq to systematically map 46 cell populations and states with minimal tissue processing. Our approach captured the emergence of Krt8+/Cdkn1a+ transitional alveolar cells and an expansion of macrophage populations during injury. Additionally, we identified sizeable populations of rare cell types, such as pericytes, and cells sensitive to digestion protocols, including a population of activated fibroblasts. These results indicate that snRNA-seq recapitulates the dynamic changes associated with injury as previously reported using single-cell methods and outperforms these approaches in the representation of cell types that are sensitive to processing, thereby highlighting its utility for high resolution analysis of heterogenous tissues such as lung.

bioinformatics↗

PERICYTE-LIKE CELLS UNDERGO TRANSCRIPTIONAL REPROGRAMMING AND DISTINCT FUNCTIONAL ADAPTATIONS IN ACUTE LUNG INJURY

BackgroundWe previously reported on the role of pericyte-like cells as functional sentinel immune cells in lung injury. However, much about the biological role of pericytes in lung injury remains unknown. Lung pericyte-like cells are well-positioned to sense disruption to the epithelial barrier and coordinate local inflammatory responses due to their anatomic niche within the alveoli. In this report, we characterized transcriptional responses and functional changes in pericyte-like cells following activation by alveolar components from injured and uninjured lungs in a mouse model of acute lung injury (ALI). MethodsWe purified pericyte-like cells from lung digests using PDGFR{beta} as a selection marker and expanded them in culture as previously described (1). We induced sterile acute lung injury in mice with recombinant human Fas ligand (rhFasL) instillation followed by mechanical ventilation (1). We then collected bronchoalveolar lavage fluid (BALF) from injured and uninjured mice. Purified pericyte-like cells in culture were exposed to growth media only (control), BALF from uninjured mice, and BALF from injured mice for 6 and 24 h. RNA collected from these treatment conditions were processed for RNAseq. Targets of interest identified by pathway analysis were validated using in vitro and in vivo assays. ResultsWe observed robust global transcriptional changes in pericyte-like cells following treatment with uninjured and injured BALF at 6 h, but this response persisted for 24 h only after exposure to injured BALF. Functional enrichment analysis of pericytes treated with injured BALF revealed activation of immuno-inflammatory, cell migration and angiogenesis-related pathways, whereas processes associated with tissue development and remodeling were down-regulated. We validated select targets in the inflammatory, angiogenesis-related, and cell migratory pathways using functional biological assays in vitro and in vivo. ConclusionLung pericyte-like cells are highly responsive to alveolar compartment content from both uninjured and injured lungs, but injured BALF elicits a more sustained response. The inflammatory, angiogenic, and migratory changes exhibited by activated pericyte-like cells underscore the phenotypic plasticity of these specialized stromal cells in the setting of acute lung injury.

cell biology↗