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Biology subjects

Cantu, E.

Publications and source records attributed to Cantu, E..

7 recordsLinked to original sources

A Single-Cell Atlas of PVOD Across the Lifespan Reveals Cellular and Molecular Therapeutic Targets

Rationale Pulmonary veno-occlusive disease (PVOD) is a progressive and lethal disease cured only lung transplant. While genetic mutations in EIF2AK4 have been identified in some cases, 70% of PVOD patients have no known etiology. Objectives To construct a single-cell atlas to define the cellular and molecular constituents driving pathophysiology in PVOD. Methods Lung samples were collected from four idiopathic non-EIF2AK4 mutation pediatric and adult PVOD patients and age-matched controls. Analyses of single-cell RNA sequencing, Xenium spatial transcriptomics, and immunohistochemistry were performed to identify cell state changes and differential gene expression between controls and PVOD and subsequent transcriptome comparison between our PVOD and published pulmonary arterial hypertension (PAH) datasets. Measurement and Main Results The single-cell atlas reveals marked changes in the PVOD endothelium compared to controls. EndMT and ectopic COL15A1+ systemic venous shunts and pulmonary vein endothelium are hallmarks of PVOD. Molecular analyses reveal activation of the integrated stress response (ISR)/ATF4, TGF{beta} signaling, MAPK signaling, and BRD4 are potential key players in the pathophysiology of PVOD. While PVOD and PAH share both pathological and some molecular mechanisms, ISR and TGF{beta} signaling are more prominent in PVOD than PAH. Conclusions These data indicate that endothelial dysfunction is a primary etiology in the development of PVOD with activation of multiple pathways with druggable targets.

molecular biology↗

A postnatal human lung developmental atlas reveals windows of genetic vulnerability to chronic lung disease

At birth, the lungs undergo an abrupt physiologic change, as the function of gas exchange transitions from the placenta to the lung. Subsequent postnatal development of the lungs is marked by a rapid and profound increase in the growth of the distal airways and alveolar gas exchange compartment. Insults during this period increase the risk of developing lung disease later in life, though how early-life events affect adult disease onset remains unclear. We generated a single-cell atlas of postnatal human lung development from birth through adulthood and mapped temporally regulated gene expression changes in each cell lineage. Using this atlas, we identified disease risk-associated genes with developmentally regulated expression. These analyses reveal cell type-specific and temporally restricted expression of genes associated with adult lung disease risk, including COPD. Heritability enrichment analysis demonstrated that COPD genetic risk is enriched in genes active during early postnatal endothelial development, linking early-life vascular maturation to adult disease susceptibility. These findings characterize the early window of susceptibility for adult chronic lung diseases and establish a framework to guide mechanistic studies of disease-associated genes.

developmental biology↗

Marginated neutrophils in the lungs effectively compete for nanoparticles targeted to the endothelium, serving as a part of the reticuloendothelial system

Nanomedicine has long pursued the goal of targeted delivery to specific organs and cell types but has not achieved this goal with the vast majority of targets. One rare example of success in this pursuit has been the 25+ years of studies targeting the lung endothelium using nanoparticles conjugated to antibodies against endothelial surface molecules. However, here we show that such "endothelial-targeted" nanocarriers also effectively target the lungs numerous marginated neutrophils, which reside in the pulmonary capillaries and patrol for pathogens. We show that marginated neutrophils uptake of many of these "endothelial-targeted" nanocarriers is on par with endothelial uptake. This generalizes across diverse nanomaterials and targeting moieties and was even found with physicochemical lung tropism (i.e., without targeting moieties). Further, we observed this in ex vivo human lungs and in vivo healthy mice, with an increase in marginated neutrophil uptake of nanoparticles caused by local or distant inflammation. These findings have implications for nanomedicine development for lung diseases. These data also suggest that marginated neutrophils, especially in the lungs, should be considered a major part of the reticuloendothelial system (RES), with a special role in clearing nanoparticles that adhere to the lumenal surfaces of blood vessels. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=172 SRC="FIGDIR/small/597904v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@17e0518org.highwire.dtl.DTLVardef@809eb6org.highwire.dtl.DTLVardef@33d9a7org.highwire.dtl.DTLVardef@169863_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

A longitudinal atlas of post-viral lung regeneration reveals persistent injury-associated cell states

Functional regeneration of the lungs gas exchange surface following injury requires the coordination of a complex series of cell behaviors within the alveolar niche. Using a multi-modal approach, we have mapped the temporal sequencing of mouse lung regeneration after acute viral injury, demonstrating that this response is asynchronously phased across different cellular compartments. This longitudinal atlas of regeneration has produced a catalogue of new cell states that reflect transient and persistent transcriptional alterations in daughter cells as they transit across axes of differentiation. These new cell states include an injury-induced capillary endothelial cell (iCAP) that arises after injury, persists indefinitely, and shares transcriptional hallmarks with both developing lung endothelium and the endothelial aberrations found in degenerative human lung diseases. This comprehensive atlas of lung regeneration provides a foundational resource to understand the complexity of the cellular and molecular responses to injury, reveals the critical importance of capillary endothelium in maintaining and rebuilding the alveolar niche after injury, and correlates these responses to those found in development and human lung diseases.

cell biology↗

An injury-induced tissue niche shaped by mesenchymal plasticity coordinates the regenerative and disease response in the lung

Severe lung injury causes basal stem cells to migrate and outcompete alveolar stem cells resulting in dysplastic repair and a loss of gas exchange function. This "stem cell collision" is part of a multistep process that is now revealed to generate an injury-induced tissue niche (iTCH) containing Keratin 5+ epithelial cells and plastic Pdgfra+ mesenchymal cells. Temporal and spatial single cell analysis reveals that iTCHs are governed by mesenchymal proliferation and Notch signaling, which suppresses Wnt and Fgf signaling in iTCHs. Conversely, loss of Notch in iTCHs rewires alveolar signaling patterns to promote euplastic regeneration and gas exchange. The signaling patterns of iTCHs can differentially phenotype fibrotic from degenerative human lung diseases, through apposing flows of FGF and WNT signaling. These data reveal the emergence of an injury and disease associated iTCH in the lung and the ability of using iTCH specific signaling patterns to discriminate human lung disease phenotypes.

cell biology↗

Vascular Endothelial-derived SPARCL1 Exacerbates Viral Pneumonia Through Pro-Inflammatory Macrophage Activation

Inflammation upon infectious lung injury is a double-edged sword: while tissue-infiltrating immune cells and cytokines are necessary to control infection, these same factors often aggravate injury. Full appreciation of both the sources and targets of inflammatory mediators is required to facilitate strategies to maintain antimicrobial effects while minimizing off-target epithelial and endothelial damage. Recognizing that the vasculature is centrally involved in tissue responses to injury and infection, we observed that pulmonary capillary endothelial cells (ECs) exhibit dramatic transcriptomic changes upon influenza injury punctuated by profound upregulation of Sparcl1. Endothelial deletion and overexpression of SPARCL1 implicated this secreted matricellular protein in driving key pathophysiologic symptoms of pneumonia, which we demonstrate result from its effects on macrophage polarization. SPARCL1 induces a shift to a pro-inflammatory "M1-like" phenotype (CD86+CD206-), thereby increasing associated cytokine levels. Mechanistically, SPARCL1 acts directly on macrophages in vitro to induce the pro-inflammatory phenotype via activation of TLR4, and TLR4 inhibition in vivo ameliorates inflammatory exacerbations caused by endothelial Sparcl1 overexpression. Finally, we confirmed significant elevation of SPARCL1 in COVID-19 lung ECs in comparison with those from healthy donors. Survival analysis demonstrated that patients with fatal COVID-19 had higher levels of circulating SPARCL1 protein compared to those who recovered, indicating the potential of SPARCL1 as a biomarker for prognosis of pneumonia and suggesting that personalized medicine approaches might be harnessed to block SPARCL1 and improve outcomes in high-expressing patients.

immunology↗

Hyperactive mTOR in Lung Mesenchyme Induces Endothelial Dysfunction and Pulmonary Vascular Remodeling

Pulmonary vascular remodeling is the key structural abnormality in pulmonary hypertension (PH). Mechanistic target of rapamycin (mTOR) has long been suspected to play a role in the development of pulmonary vascular remodeling. However, underlying cellular and molecular mechanisms leading to this pathophysiological condition remain incompletely understood. To elucidate the crosstalk between lung mesenchyme with activated mTOR and endothelial cells (ECs), we focused on a monogenic lung disease, pulmonary lymphangioleiomyomatosis (LAM). LAM is a progressive cystic lung disease caused by a mutational inactivation of tuberous sclerosis complex (TSC1/TSC2), which results in constitutive mTOR activation in mesenchymal LAM cells. ECs derived from LAM lung explants showed increased proliferation, migration, and defective angiogenesis compared to age- and sex-matched ECs from control human lung. In LAM cells, we found increased WNT2 ligand expression. We also identified corresponding Frizzled 4 (FZD) receptors on ECs isolated from distal LAM lung, suggesting cellular crosstalk between LAM cells and ECs. In endothelial-fibroblast cocultures, treatment of normal ECs with WNT2 ligands recapitulated LAM EC phenotype and morphology. We observed transcriptomic upregulation in metabolic, angiogenic and growth pathways in ECs of young mice, while 1-year-old Tsc2KO mice spontaneously developed pulmonary vascular remodeling with concurrent elevation in right ventricular systolic pressure. Our study demonstrates that LAM cells are not just a pathological mesenchymal cell state but a signaling hub that contributes to dysregulated cellular response in the surrounding vasculature, eventual pulmonary vascular remodeling and PH.

molecular biology↗