Biology subjects

Lopez-Rodriguez, E.

Publications and source records attributed to Lopez-Rodriguez, E..

3 recordsLinked to original sources

bioRxiv2024

Neutrophil-chemoattractant CXCL5 induces lung barrier permeability in acute lung injury

RationaleAcute lung injury is frequently caused by pneumonia, and severity correlates with inflammatory cell recruitment and lung barrier failure. Deciphering drug-targetable pathways is of clinical importance. ObjectivesInvestigation of paracrine and autocrine effects of epithelial-derived chemokine CXCL5 in acute lung injury. MethodsWe assessed the role of CXCL5 and related chemokines in patients with severe pneumonia and primary cells or cell lines challenged with Streptococcus pneumoniae or exposed to mechanical stretch. Furthermore, we evaluated the role of CXCL5 in in vivo models of acute lung injury through use of Cxcl5-deficient mice and in vitro human lung barrier models. ResultsPneumococcal infection and mechanical ventilation were associated with CXCL5 production in human subjects and in mice. CXCL5 was produced by bronchial and alveolar epithelial cells. The alveolar-epithelial barrier was protected in acute lung injury models in Cxcl5-deficient mice, independent of alveolar neutrophil recruitment. Single-cell transcriptomics revealed enhanced cell junctional transcripts in epithelial, but not endothelial cells in Cxcl5-deficient mice. Accordingly, CXCL5 exposure disrupted the barrier function of TNF-primed human primary alveolar epithelial cells, but not pulmonary microvascular endothelial cells. ConclusionsWe describe a novel function of CXCL5 in acute lung injury. Besides its recognized role in recruiting highly inflammatory cells such as neutrophils, CXCL5 increases alveolar-epithelial barrier permeability. Thus, in severe bacterial pneumonia, targeting of CXCL5 as adjunctive therapy to antibiotics may aid in reducing overshooting inflammation as well as stabilizing lung barrier function.

immunology↗

bioRxiv2024

Cell surface RNA expression modulates alveolar epithelial function

Glycosylated RNA (glycoRNA) has recently emerged as a novel constituent of the glycocalyx on cell surfaces, yet its biological functions remain largely unexplored. In this report, we present the first analysis of glycoRNA expression and functionality in alveolar epithelial cells. To this end, we optimized new techniques for the detection of glycoRNA on living cell surfaces and in cell membrane-associated RNA samples through in-gel imaging after labeling with fluorescent dye conjugates. Specifically, we used conjugation of Cy5-hydrazide following mild oxidation with sodium periodate for detection of the entire cell surface sialoglycoRNA pool. Conjugation of dibenzocyclooctyne-sulfo-Cy5 (DBCO-Sulfo-Cy5) in cells fed with tetraacetylated N-azidoacetyl-mannosamine (Ac4ManNAz) or 6-azido-L-fucose (FucAz) detected de novo formed sialoglycoRNA or fucoglycoRNA. Finally, biotinylated lectins in combination with infrared dye-conjugated streptavidin was used to differentiate between specific glycosidic linkages. Comparisons across primary alveolar epithelial cells and different alveolar-epithelial like cell lines revealed a cell-type specific variation in glycoRNA abundance. Treatment of primary alveolar epithelial cells with an RNAse cocktail reduced epithelial surface glycoRNA and was associated with a reduction in trans-epithelial electrical resistance and influenza A viral particle abundance. As such, the present work identifies glycoRNA as a novel component of the alveolar epithelial glycocalyx, suggesting its potential relevance in epithelial barrier regulation and viral infection.

physiology↗

bioRxiv2024

Enzymatic modulation of the pulmonary glycocalyx alters susceptibility to Streptococcus pneumoniae

The pulmonary epithelial glycocalyx is rich in glycosaminoglycans such as hyaluronan and heparan sulfate. Despite their presence, the precise role of these glycosaminoglycans in bacterial lung infections remains elusive. To address this, we intranasally inoculated mice with Streptococcus pneumoniae in the presence or absence of enzymes targeting pulmonary hyaluronan and heparan sulfate, followed by characterization of subsequent disease pathology, pulmonary inflammation, and lung barrier dysfunction. Enzymatic degradation of hyaluronan and heparan sulfate exacerbated pneumonia in mice, as evidenced by increased disease scores and alveolar neutrophil recruitment. However, targeting epithelial hyaluronan further exacerbated systemic disease, indicated by elevated splenic bacterial load and plasma levels of pro-inflammatory cytokines. In contrast, enzymatic cleavage of heparan sulfate resulted in increased bronchoalveolar bacterial burden, lung damage and pulmonary inflammation in mice infected with Streptococcus pneumoniae. Accordingly, heparinase-treated mice also exhibited disrupted lung barrier integrity as evidenced by higher alveolar edema scores and vascular protein leakage into the airways. This finding was corroborated in a human alveolus-on-a-chip platform, confirming that heparinase treatment also disrupts the human lung barrier. Notably, enzymatic pre-treatment with either hyaluronidase or heparinase also rendered human epithelial cells more sensitive to pneumococcal-induced barrier disruption, as determined by transepithelial electrical resistance measurements, consistent with our findings in murine pneumonia. Taken together, these findings demonstrate the importance of intact hyaluronan and heparan sulfate in controlling pneumococcal virulence, pulmonary inflammation, and epithelial barrier function.

molecular biology↗