Apyrase treatment prevents ischemia–reperfusion injury in rat lung isografts

ObjectiveEndothelial cells express the ectoenzyme ectonucleoside adenosine triphosphate diphosphohydrolase, an apyrase that inhibits vascular inflammation by catalyzing the hydrolysis of adenosine triphosphate and adenosine diphosphate. However, ectonucleoside adenosine triphosphate diphosphohydrolase expression is rapidly lost following oxidative stress, leading to the potential for adenosine triphosphate and related purigenic nucleotides to exacerbate acute solid organ inflammation and injury. We asked if administration of a soluble recombinant apyrase APT102 attenuates lung graft injury in a cold ischemia reperfusion model of rat syngeneic orthotopic lung transplantation.MethodsMale Fisher 344 donor lungs were cold preserved in a low-potassium dextrose solution in the presence or absence of APT102 for 18 hours prior to transplantation into syngeneic male Fisher 344 recipients. Seven minutes after reperfusion, lung transplant recipients received either a bolus of APT102 or vehicle (saline solution). Four hours after reperfusion, APT102- and saline solution–treated groups were evaluated for lung graft function and inflammation.ResultsAPT102 significantly reduced lung graft extracellular pools of adenosine triphosphate and adenosine diphosphate, improved oxygenation, and protected against pulmonary edema. Apyrase treatment was associated with attenuated neutrophil graft sequestration and less evidence of tissue inflammation as assessed by myeloperoxidase activity, expression of proinflammatory mediators, and numbers of apoptotic endothelial cells.ConclusionsAdministration of a soluble recombinant apyrase promotes lung function and limits the tissue damage induced by prolonged cold storage, indicating that extracellular purigenic nucleotides play a key role in promoting ischemia–reperfusion injury following lung transplantation

Inflammatory and Remodeling Events in Asthma with Chronic Exposure to House Dust Mites: A Murine Model

Although animal models with ovalbumin have been used to study chronic asthma, there are difficulties in inducing recurrence as well as in maintaining chronic inflammation in this system. Using a murine model of house dust mite (HDM)-induced bronchial asthma, we examined the airway remodeling process in response to the chronic exposure to HDM. During the seventh and twelfth weeks of study, HDM were inhaled through the nose for three consecutive days and airway responsiveness was measured. Twenty-four hours later, bronchoalveolar lavage and histological examination were performed. The degree of overproduction of mucus, subepithelial fibrosis, and the thickness of the peribronchial smooth muscle in the experimental group was clearly increased compared to the control group. In addition, HDM-exposed mice demonstrated severe airway hyperreactivity to methacholine. In the bronchoalveolar lavage fluid, the number of total cells and eosinophils was increased; during the twelfth week, the number of neutrophils increased in the experimental group. With regard to changes in cytokines, the concentrations of IL-4, IL-13, and transforming growth factor-beta (TGF-β) were increased in the experimental group. The data suggest that eosinophils, IL-4, IL-13, and TGF-β might play an important role in the airway remodeling process and that neutrophils may be involved with increased exposure time

Time Sequence of Airway Remodeling in a Mouse Model of Chronic Asthma: the Relation with Airway Hyperresponsiveness

During the course of establishing an animal model of chronic asthma, we tried to elucidate the time sequence of airway hyperresponsiveness (AHR), airway inflammation, airway remodeling, and associated cytokines. Seven-week-old female BALB/c mice were studied as a chronic asthma model using ovalbumin (OVA). After sensitization, mice were exposed twice weekly to aerosolized OVA, and were divided into three groups depending on the duration of 4 weeks, 8 weeks, and 12 weeks. At each time point, airway responsiveness, inflammatory cells, cytokines in bronchoalveolar lavage fluids (BALF), serum OVA-specific IgE, IgG1, IgG2a, and histological examination were carried out. AHR to methacholine, increased levels of OVA-specific IgG1 and IgG2a, and goblet cell hyperplasia were continuously sustained at each time point of weeks. In contrast, we observed a time-dependent decrease in serum OVA-specific IgE, BALF eosinophils, BALF cytokines such as IL-13, transforming growth factor-beta1, and a time-dependent increase in BALF promatrix metalloproteinase-9 and peribronchial fibrosis. In this OVA-induced chronic asthma model, we observed airway remodelings as well as various cytokines and inflammatory cells being involved in different time-dependent manners. However, increased airway fibrosis did not directly correlate with a further increase in airway hyperresponsiveness

The Soluble Tumor Necrosis Factor-Alpha Receptor Suppresses Airway Inflammation in a Murine Model of Acute Asthma

Asthma is a T helper 2 (Th2)-mediated inflammatory airway disease, characterized by airway hyperresponsiveness (AHR), chronic eosinophilic inflammation, episode of reversible bronchoconstriction, and mucus hypersecretion. In these responsies, several cytokines are considered to take part in a pivotal role. Although Th2 cytokines, including interleukin (IL)-4, IL-5 and IL-13, are important in asthma,1 tumor necrosis factor (TNF)-α has been implicated in the inflammatory response, seen in asthma.2 TNF-α is a multifunctional proinflammatory cytokine, and a chemoattractant for neutrophils and eosinophils.3 It increases the cytotoxic effect of eosinophils on endothelial cells,4 epithelial expression of adhesion molecules, such as intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1),6 and the contractile function of smooth muscles,7 and is involved in the activation of T cells.5 Howarth et al.8 reported that TNF-α concentration in bronchoalveolar lavage fluid (BALF) and TNF-α protein and messenger RNA (mRNA) expression in bronchial biopsy specimens were increased in patients with severe asthma compared those with mild disease

Low ARID1A Expression is Associated with Poor Prognosis in Hepatocellular Carcinoma

AT-rich interactive domain 1A (ARID1A) is one of the most frequently mutated genes in hepatocellular carcinoma (HCC), but its clinical significance is not clarified. We aimed to evaluate the clinical significance of low ARID1A expression in HCC. By analyzing the gene expression data of liver from Arid1a-knockout mice, hepatic Arid1a-specific gene expression signature was identified (p < 0.05 and 0.5-fold difference). From this signature, a prediction model was developed to identify tissues lacking Arid1a activity and was applied to gene expression data from three independent cohorts of HCC patients to stratify patients according to ARID1A activity. The molecular features associated with loss of ARID1A were analyzed using The Cancer Genome Atlas (TCGA) multi-platform data, and Ingenuity Pathway Analysis (IPA) was done to uncover potential signaling pathways associated with ARID1A loss. ARID1A inactivation was clinically associated with poor prognosis in all three independent cohorts and was consistently related to poor prognosis subtypes of previously reported gene signatures (highly proliferative, hepatic stem cell, silence of Hippo pathway, and high recurrence signatures). Immune activity, indicated by significantly lower IFNG6 and cytolytic activity scores and enrichment of regulatory T-cell composition, was lower in the ARID1A-low subtype than ARID1A-high subtype. Ingenuity pathway analysis revealed that direct upstream transcription regulators of the ARID1A signature were genes associated with cell cycle, including E2F group, CCND1, and MYC, while tumor suppressors such as TP53, SMAD3, and CTNNB1 were significantly inhibited. ARID1A plays an important role in immune activity and regulating multiple genes involved in HCC development. Low-ARID1A subtype was associated with poor clinical outcome and suggests the possibility of ARID1A as a prognostic biomarker in HCC patients