AMD3100 ameliorates cigarette smoke-induced emphysema-like manifestations in mice.

We have shown that cigarette smoke (CS)-induced pulmonary emphysema-like manifestations are preceded by marked suppression of the number and function of bone marrow hematopoietic progenitor cells (HPCs). To investigate whether a limited availability of HPCs may contribute to CS-induced lung injury, we used a Food and Drug Administration-approved antagonist of the interactions of stromal cell-derived factor 1 (SDF-1) with its chemokine receptor CXCR4 to promote intermittent HPC mobilization and tested its ability to limit emphysema-like injury following chronic CS. We administered AMD3100 (5mg/kg) to mice during a chronic CS exposure protocol of up to 24 wk. AMD3100 treatment did not affect either lung SDF-1 levels, which were reduced by CS, or lung inflammatory cell counts. However, AMD3100 markedly improved CS-induced bone marrow HPC suppression and significantly ameliorated emphysema-like end points, such as alveolar airspace size, lung volumes, and lung static compliance. These results suggest that antagonism of SDF-1 binding to CXCR4 is associated with protection of both bone marrow and lungs during chronic CS exposure, thus encouraging future studies of potential therapeutic benefit of AMD3100 in emphysema.

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration Use for Subclassification and Genotyping of Lung Non-Small-Cell Carcinoma.

OBJECTIVES: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the primary method for the diagnosis and staging of lung cancer. The purpose of this study was to assess the yield of EBUS-TBNA in the subtyping and genotyping of lung adenocarcinoma. METHODS: Sixty-nine patients at Indiana University Hospital and Sidney and Lois Eskenazi Hospital with possible or confirmed lung adenocarcinoma underwent EBUS-TBNA using a 21-gauge Olympus needle without suction. Samples were sent for molecular testing after rapid onsite specimen evaluation. A total of 6 to 10 passes were placed in a cell block. RESULTS: Sixty-nine samples from patients with non-small-cell lung cancer were sent for molecular testing for epidermal growth factor receptor. Results were obtained in all of the patients. Mutations were found in three patients (4.3%). Fifty-eight samples were sent for V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (100% yield), 10 of which had mutations (17.2%). Fifty-one samples were sent for proto-oncogene tyrosine-protein kinase ROS testing (1 [7.8%] mutant). Tissue samples were inadequate in three patients (94.1% yield). Sixty-three samples were sent for anaplastic lymphoma receptor tyrosine kinase testing (3 [4.8%] mutant, 6 [9.5%] inadequate, 90.5% yield). CONCLUSIONS: EBUS-TBNA with a 21-gauge needle is appropriate for the analysis of multiple mutations and the genotyping of lung adenocarcinoma.

Active trafficking of alpha 1 antitrypsin across the lung endothelium.

The homeostatic lung protective effects of alpha-1 antitrypsin (A1AT) may require the transport of circulating proteinase inhibitor across an intact lung endothelial barrier. We hypothesized that uninjured pulmonary endothelial cells transport A1AT to lung epithelial cells. Purified human A1AT was rapidly taken up by confluent primary rat pulmonary endothelial cell monolayers, was secreted extracellularly, both apically and basolaterally, and was taken up by adjacent rat lung epithelial cells co-cultured on polarized transwells. Similarly, polarized primary human lung epithelial cells took up basolaterally-, but not apically-supplied A1AT, followed by apical secretion. Evidence of A1AT transcytosis across lung microcirculation was confirmed in vivo by two-photon intravital microscopy in mice. Time-lapse confocal microscopy indicated that A1AT co-localized with Golgi in the endothelium whilst inhibition of the classical secretory pathway with tunicamycin significantly increased intracellular retention of A1AT. However, inhibition of Golgi secretion promoted non-classical A1AT secretion, associated with microparticle release. Polymerized A1AT or A1AT supplied to endothelial cells exposed to soluble cigarette smoke extract had decreased transcytosis. These results suggest previously unappreciated pathways of A1AT bidirectional uptake and secretion from lung endothelial cells towards the alveolar epithelium and airspaces. A1AT trafficking may determine its functional bioavailablity in the lung, which could be impaired in individuals exposed to smoking or in those with A1AT deficiency.