RESUMEN
Exposure to chlorine (Cl2) gas during industrial accidents or chemical warfare leads to significant airway and distal lung epithelial injury that continues post exposure. While lung epithelial injury is prevalent, relatively little is known about whether Cl2 gas also promotes injury to the pulmonary vasculature. To determine this, rats were subjected to a sub-lethal Cl2 gas exposure (400 ppm, 30 min) and then brought back to room air. Pulmonary arteries (PA) were isolated from rats at various times post-exposure and contractile (phenylephrine) and nitric oxide (NO)-dependent vasodilation (acetylcholine and mahmanonoate) responses measured ex vivo. PA contractility did not change, however significant inhibition of NO-dependent vasodilation was observed that was maximal at 24-48 h post exposure. Superoxide dismutase restored NO-dependent vasodilation suggesting a role for increased superoxide formation. This was supported by â¼2-fold increase in superoxide formation (measured using 2-hydroethidine oxidation to 2-OH-E+) from PA isolated from Cl2 exposed rats. We next measured PA pressures in anesthetized rats. Surprisingly, PA pressures were significantly (â¼4 mmHg) lower in rats that had been exposed to Cl2 gas 24 h earlier suggesting that deficit in NO-signaling observed in isolated PA experiments did not manifest as increased PA pressures in vivo. Administration of the iNOS selective inhibitor 1400W, restored PA pressures to normal in Cl2 exposed, but not control rats suggesting that any deficit in NO-signaling due to increased superoxide formation in the PA, is offset by increased NO-formation from iNOS. These data indicate that disruption of endogenous NO-signaling mechanisms that maintain PA tone is an important aspect of post-Cl2 gas exposure toxicity.
Asunto(s)
Cloro/toxicidad , Homeostasis/efectos de los fármacos , Pulmón/metabolismo , Óxido Nítrico/metabolismo , Circulación Pulmonar/efectos de los fármacos , Animales , Inhibidores Enzimáticos/farmacología , Gases , Masculino , Tono Muscular/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico Sintasa/metabolismo , Nitritos/metabolismo , Arteria Pulmonar/efectos de los fármacos , Arteria Pulmonar/metabolismo , Presión Esfenoidal Pulmonar/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Superóxidos/metabolismo , Vasoconstricción/efectos de los fármacos , Vasodilatación/efectos de los fármacosRESUMEN
BACKGROUND: Endothelial cell responses during inflammation are heterogeneous and key for selectivity in how leukocytes hone in on specific sites and why vascular diseases are highly bed specific. However, mechanisms for this specificity remain unclear. METHODS AND RESULTS: Here, we exposed human endothelial cells isolated from 5 systemic arterial beds from 1 donor (to overcome donor-to-donor genetic/epigenetic differences), the umbilical vein, and pulmonary microvasculature to TNF-α, LPS, and IL-1ß and assessed acute (ERK1/2 and p65) and chronic (ICAM-1, VCAM-1 total and surface expression) signaling responses and assessed changes in surface N-glycans and monocyte adhesion. Significant diversity in responses was evident by disparate changes in ERK1/2 and p65 NF-κB phosphorylation, which varied up to 5-fold between different cells and in temporal and magnitude differences in ICAM-1 and VCAM-1 expression (maximal VCAM-1 induction typically being observed by 4 hours, whereas ICAM-1 expression was increased further at 24 hours relative to 4 hours). N-glycan profiles both basally and with stimulation were also bed specific, with hypoglycosylated N-glycans correlating with increased THP-1 monocyte adhesion. Differences in surface N-glycan expression tracked with dynamic up- or downregulation of α-mannosidase activity during inflammation. CONCLUSIONS: These results demonstrate a critical role for the vascular bed of origin in controlling endothelial responses and function to inflammatory stimuli and suggest that bed-specific expression of N-linked sugars may provide a signature for select leukocyte recruitment.
Asunto(s)
Células Endoteliales/metabolismo , Mediadores de Inflamación/metabolismo , Inflamación/metabolismo , Pulmón/irrigación sanguínea , Aorta/inmunología , Aorta/metabolismo , Tronco Braquiocefálico/inmunología , Tronco Braquiocefálico/metabolismo , Arterias Carótidas/inmunología , Arterias Carótidas/metabolismo , Adhesión Celular , Línea Celular , Quimiotaxis de Leucocito , Vasos Coronarios/inmunología , Vasos Coronarios/metabolismo , Células Endoteliales/efectos de los fármacos , Células Endoteliales/inmunología , Femenino , Glicosilación , Células Endoteliales de la Vena Umbilical Humana/inmunología , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Inflamación/inmunología , Molécula 1 de Adhesión Intercelular/metabolismo , Interleucina-1beta/metabolismo , Lipopolisacáridos/farmacología , Masculino , Microvasos/inmunología , Microvasos/metabolismo , Persona de Mediana Edad , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Monocitos/inmunología , Monocitos/metabolismo , Fosforilación , Transducción de Señal , Arteria Subclavia/inmunología , Arteria Subclavia/metabolismo , Factores de Tiempo , Factor de Transcripción ReIA/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Molécula 1 de Adhesión Celular Vascular/metabolismoRESUMEN
Neutropenia is common to both Hermansky-Pudlak syndrome type 2 and canine cyclic hematopoiesis (CH) which are caused by mutations in the AP3B1 gene. The purpose of this study was to determine if pearl mice were neutropenic. Complete blood counts (CBCs) and bone marrow differential counts, colony forming unit (CFU) assay, bone marrow lineage negative (lin(-)), Sca(+) and c-kit(+) cells (LSK cells), bone marrow elastase, myeloperoxidase, and cathepsin G enzyme activity were compared in C57Bl6 (Bl/6) and pearl mice. Stress granulopoiesis was evaluated following 200 mg/kg cyclophosphamide or 1 mg/kg bortezomib administration and by limiting dilution bone marrow transplantation. The CBCs and CFUs were determined in Bl/6 and pearl mice following AMD3100 or granulocyte colony-stimulating factor (G-CSF) administration. Pearl mice were not neutropenic and did not have cyclic neutropenia. Bone marrow elastase, myeloperoxidase, and cathepsin G enzyme activity were similar in pearl and Bl/6 mice. The numbers of CFU-G, CFU-GEMM, and LSK cells were increased moderately in pearl mice. Stress granulopoiesis was similar in Bl/6 and pearl mice. CFU assays and CBCs performed on Bl/6 and pearl mice administered AMD3100 resulted in similar results. However, normal mice administered G-CSF had higher peripheral blood neutrophil counts and greater CFU numbers compared with pearl mice. Unlike patients with HPS-2 and dogs with CH, pearl mice did not have neutropenia or CH but had decreased hematopoietic progenitor cell and granulocyte mobilization in response to G-CSF.