The master transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) regulates the expression of antioxidant and phase II-metabolizing enzymes by activating the antioxidant response element (ARE) and thereby protects cells and tissues from oxidative stress. Pulmonary complications remain the leading cause of death in human immunodeficiency virus (HIV)-1-infected individuals, who display systemic oxidative stress and glutathione deficiency that can be modeled in transgenic rats where HIV-1-related viral proteins decrease glutathione levels and cause epithelial barrier dysfunction within the alveolar space by as yet unknown mechanisms. We hypothesized that HIV-1-related proteins inhibit Nrf2-mediated antioxidant defenses and thereby disrupt the normally tight alveolar epithelial barrier. Nrf2 RNA silencing dampened Nrf2/ARE activity, decreased the expression of the tight junction proteins zonula occludens-1, occludin, and claudin-18, increased paracellular permeability of alveolar epithelial monolayers derived from wild-type rats, and therefore reproduced the effects of HIV-1 transgene expression on the epithelial barrier that we had previously described. In contrast, upregulating Nrf2 activity, either by plasmid-mediated overexpression or treatment with the Nrf2 activator sulforaphane, increased the expression of ARE-dependent antioxidants, including NAD(P)H dehydrogenase, quinone 1 and glutathione, improved the expression of tight junction proteins, and restored the ability to form tight barriers in alveolar epithelial cells from HIV-1 transgenic rats. Taken together, these new findings argue that HIV-1-related proteins downregulate Nrf2 expression and/or activity within the alveolar epithelium, which in turn impairs antioxidant defenses and barrier function, thereby rendering the lung susceptible to oxidative stress and injury. Furthermore, this study suggests that activating the Nrf2/ARE pathway with the dietary supplement sulforaphane could augment antioxidant defenses and lung health in HIV-1-infected individuals.

Excessive alcohol use increases the risk of acute lung injury and pneumonia. Chronic alcohol ingestion causes oxidative stress within the alveolar space, including near depletion of glutathione (GSH), which impairs alveolar epithelial and macrophage function, in experimental animals and human subjects. However, the fundamental mechanism(s) by which alcohol induces such profound lung oxidative stress is unknown. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a redoxsensitive master transcription factor that regulates activation of the antioxidant response element (ARE). As the alveolar epithelium controls GSH levels within the alveolar space, we hypothesized that alcohol also decreases Nrf2 expression and/or activation within the alveolar epithelium. In this study, we determined that alcohol ingestion in vivo or direct alcohol exposure in vitro down-regulated the Nrf2-ARE pathway in lung epithelial cells, decreased the expression of antioxidant genes, and lowered intracellular GSH levels. RNA silencing of Nrf2 gene expression in alveolar epithelial cells in vitro decreased expression of these same antioxidant genes, and likewise lowered intracellular GSH levels, findings that mirrored the effects of alcohol. In contrast, treating alcoholexposed alveolar epithelial cells in vitro with the Nrf2 activator, sulforaphane, preserved Nrf2 expression, ARE activation, intracellular GSH levels, and epithelial barrier function. These new experimental findings implicate down-regulation of the Nrf2-ARE signaling pathway as a fundamental mechanism by which alcohol causes profound oxidative stress and alveolar epithelial dysfunction, and suggest that treatments, such as sulforaphane, that activate this pathway could mitigate the pathophysiological consequences of alcohol on the lung and other organs.Keywords: acute respiratory distress syndrome; glutathione; lung; redox signaling; oxidative stress Alcohol is the most commonly used and abused drug throughout the United States and the rest of the world. Although the overuse of alcohol is commonly associated with disorders of the liver, brain, and gastrointestinal tract, the role of alcohol in diseases of the respiratory system is becoming more widely recognized. Although a connection between alcohol abuse and pneumonia has been known for centuries, it was only in 1996 that an epidemiological association with the acute respiratory distress syndrome (ARDS) was recognized (1), an observation later validated in a prospective study (2). ARDS is a severe form of acute lung injury, characterized by alveolar epithelial barrier disruption and flooding of the alveolar space with proteinaceous fluid that interferes with gas exchange and causes profound respiratory failure. ARDS can result from a wide range of critical illnesses, including pneumonia, sepsis, massive gastric aspiration, severe burns, and trauma; recent estimates place its incidence at approximately 200,000 cases per year in the United States and, despite aggressive supportive care, is associated with a mortality rate o...

Background-Using an experimental model of airway fibrosis following lung transplantation, we recently showed that chronic alcohol ingestion by donor rats amplifies airway fibrosis in the recipient. Associated with alcohol-mediated amplification of airway fibrosis is increased transforming growth factor beta-1(TGFβ 1 ) and alpha-smooth muscle actin (α-SMA) expression. Other studies have shown that interleukin-13 (IL-13) modulates TGFβ 1 signaling during experimentally-induced airway fibrosis. Therefore, we hypothesized that IL-13 is a component of alcohol-mediated amplification of pro-fibrotic mediators in the alcoholic lung.

BackgroundAutologous hematopoietic stem cell transplantation (aHSCT) using hematopoietic progenitor cells (HPCs) has become an important therapeutic modality for patients with high‐risk malignancies. Current literature on standardized method for HPC apheresis in children is sparse and failure rate reported as high as 30%.Patients/MethodsA retrospective study of 125 pediatric patients with high‐risk malignancies undergoing aHSCT in Western Australia between 1997 and 2016 was conducted.ResultsMobilization was achieved by means of chemotherapy and granulocyte colony‐stimulating factor (G‐CSF). Patients underwent apheresis the day after CD34+ counts reached ≥20/µL and an additional dose of G‐CSF. Peripheral arterial and intravenous lines were inserted in pediatric intensive care unit under local anesthetic and/or sedation, omitting the need for general anesthesia as well as facilitating an uninterrupted apheresis flow. Larger apheresis total blood volumes were processed in patients weighing ≤20 kg. The minimal dose of ≥2 × 106 CD34+ cells/kg was successfully collected in 98.4% of all patients. The optimal dose of 3‐5 × 106 CD34+ cells/kg was collected in 96% of patients scheduled for a single aHSCT, 87.5% for tandem, and 100% for triple aHSCT. All HPC collections were completed in one apheresis session. Mobilization after ≤3 chemotherapy cycles and cycles including cyclophosphamide resulted in a significantly higher yield of CD34+ cells.ConclusionOur approach to HPC mobilization by means of chemotherapy and single myeloid growth factor combined with optimal collection timing facilitated by continuous apheresis flow resulted in highly effective HPC harvest in children and adolescents with high‐risk cancers.