Elk1 enhances inflammatory cell infiltration and exacerbates acute lung injury/acute respiratory distress syndrome by suppressing Fcgr2b transcription.

OBJECTIVE: Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with significant mortality rates. The role of Fcgr2b in the pathogenesis of ALI/ARDS is not fully elucidated. This study aimed to investigate the functions of Fcgr2b in ALI/ARDS and explore its underlying mechanisms. METHODS: Methods: In this study, rat models of ARDS and pulmonary microvascular endothelial cell (PMVEC) injury models were established through the administration of lipopolysaccharide (LPS). The expression levels of Fcgr2b and Elk1 were quantified in both LPS-induced ARDS rats and PMVECs. Subsequent gain- and loss-of-function experiments were conducted, followed by comprehensive assessments of lung tissue for pathomorphological changes, edema, glycogen storage, fibrosis, and infiltration of inflammatory cells. Additionally, bronchoalveolar lavage fluid was analyzed for T-helper 17 (Th17) cell infiltration, inflammatory response, and microvascular permeability to evaluate lung injury severity in ARDS models. Furthermore, the activity, cytotoxicity, apoptosis, and angiogenic potential of PMVECs were assessed to gauge cell injury. The interaction between Elk1 and Fcgr2b was also examined to confirm their regulatory relationship. RESULTS: In the context of LPS-induced ARDS and PMVEC injury, Fcgr2b expression was markedly reduced, whereas Elk1 expression was elevated. Overexpression of Fcgr2b led to a decrease in Th17 cell infiltration and mitigated lung tissue damage in ARDS models, in addition to reducing LPS-induced injury in PMVECs. Elk1 was found to suppress Fcgr2b transcription through the recruitment of histone 3 lysine 9 trimethylation (H3K9me3). Knockdown of Elk1 diminished Th17 cell infiltration and lung tissue damage in ARDS models, and alleviated LPS-induced injury in PMVECs, effects that were reversed upon Fcgr2b upregulation. CONCLUSION: Elk1 negatively regulates Fcgr2b transcription, thereby augmenting the inflammatory response and exacerbating lung injury in LPS-induced ALI/ARDS.

The Influence of Piriform Recess Instillation with Lidocaine Before Bronchoscopy on Post-General Anesthesia Cough: A Randomized Controlled Trial.

Background and Importance: Postoperative cough is a common complication of general anesthesia after bronchoscopy. The aim of the present study was to determine the safety profile and efficacy of piriform recess instillation with lidocaine in reducing the incidence of coughing. Objective: To what extent could piriform recess instillation with lidocaine decrease the incidence of cough at 10min after extubation? Outcome Measures and Analysis: Eighty-eight consecutive patients were equally randomized to a lidocaine group receiving piriform recess instillation with 2mL 2% lidocaine, and a normal saline group receiving piriform recess instillation with 2mL saline. The primary outcome was the incidence of cough after extubation, and the secondary outcomes were throat score at 10 min and 6 h after extubation assessed by the numerical rating scale, cough severity at 10 min and 6 h after extubation assessed by the Visual Analog Scale (VAS), 24 h 40-item Quality of Recovery Score (QoR-40), and subject-rated satisfaction score on a VAS. Main Results: Compared with saline group, the incidence of cough in lidocaine group was significantly lower (63.6% vs 86.4%, P=0.014). The sore throat score at 10 min after extubation was significantly lower (0[0,0] vs 1[0,2], P<0.001). The subject-rated overall anesthesia satisfaction score was significantly higher (84.8[±6.2] vs 76.6[±8.6], P<0.001). The severity of cough at 10 min after extubation was significantly lower (Mild: 36.4% vs 11.4%, P=0.006; Severe: 9.1% vs 43.2%, P<0.001). There was no significant difference in the sore throat score at 6 h after extubation, severity of cough at 6 h after extubation, or QoR-40 at 24 h after extubation between the two groups. Conclusion: Piriform recess instillation with lidocaine before bronchoscopy is a simple and effective method for reducing early cough intensity and alleviating early sore throat. At 6 hours, there were no differences observed between the groups. Clinical Trial Registration: Chinese Clinical Trial Registry (identifier: ChiCTR2200067087).

MiR-122-5p as a potential regulator of pulmonary vascular wall cell in idiopathic pulmonary arterial hypertension.

MicroRNAs (miRNAs) are versatile regulators of pulmonary arterial remodeling in idiopathic pulmonary arterial hypertension (IPAH). We herein aimed to characterize miRNAs in peripheral blood mononuclear cell (PBMC) and plasma exosomes, and investigate specific miRNA expression in pulmonary artery cells and lung tissues in IPAH. A co-dysregulated miRNA was identified from the miRNA expression profiles of PBMC and plasma exosomes in IPAH. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed the potential function of differentially expressed miRNAs. Real-time quantitative reverse transcription polymerase chain reaction was used to validate the expression of specific miRNAs in hypoxia-induced pulmonary microvascular endothelial cells (PMECs), pulmonary artery smooth muscle cells (PASMCs), pericyte cells (PCs), and lung tissues of patients with IPAH and rats. Finally, the miRNA-mRNA mechanisms of miR-122-5p were predicted. MiR-122-5p was the only co-upregulated miRNA in PBMC and plasma exosomes in patients with IPAH. Functional analysis of differentially expressed miRNAs revealed associations with the GO terms "transcription, DNA-templated," "cytoplasm," and "metal ion binding" in both PBMC and plasma exosomes, KEGG pathway MAPK signaling in PBMC, and KEGG-pathway human papillomavirus infection in plasma exosomes. Hypoxic PMECs and PCs, lung tissue of patients with IPAH, and rats showed increased expression of miR-122-5p, but hypoxic PASMCs showed decreased expression. And miR-122-5p mimics and inhibitor affected cell proliferation. Finally, miR-122-5p was found to potentially target DLAT (in lung tissue) and RIMS1 (in PMECs) in IPAH. According to the dual-luciferase assay, miR-122-5p bound to DLAT or RIMS1. In studies, DLAT imbalance was associated with cell proliferation and migration, RIMS1 is differentially expressed in cancer and correlated with cancer prognosis. Our findings suggest that the miR-122-5p is involved in various biological functions in the adjacent vascular wall cells in IPAH.