Rats susceptible to virus-induced asthma have a persistent virus-induced change in the predominant pulmonary form of the NF-κB inhibitor IκBα

Vitamin D ameliorates asthma-induced lung injury by regulating HIF-1α/Notch1 signaling during autophagy

Herein, we aimed to determine the effect of vitamin D (Vit D) and underlying mechanisms on asthma-induced lung injury via regulation of HIF-1α/Notch1 (hypoxia-inducible factor 1 alpha/neurogenic locus notch homolog protein 1) signaling during autophagy. We established an asthma mouse model using respiratory syncytial virus (RSV) nasal drop combined with ovalbumin (OVA) atomization. Mice were treated with different Vit D concentrations. Pathological changes and cell apoptosis were examined using hematoxylin-eosin (HE) staining and TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end-labeling) assay, respectively. Additionally, periodic acid-Schiff (PAS) and Masson's trichrome staining solutions were used to examine changes in lung tissue. Immunofluorescence determined LC 3B (microtubule-associated protein 1 light chain 3B) expression in lung tissues, whereas western blotting and immunohistochemistry were used to evaluate other proteins, including HIF-1α and Notch1. Compared with the normal group, the asthma model group exhibited pathological lung tissue deterioration, elevated fibrosis, increased apoptosis cell numbers, and upregulated autophagy. Vitamin D supplementation ameliorated pathological changes and fibrosis in the lung tissue. Furthermore, Vit D treatment significantly suppressed apoptotic cell numbers and autophagy while enhancing the HIF-1α/Notch1 pathway. Given the HIF-1α/Notch1 agonistic activity, Vit D treatment inhibited apoptosis cell numbers, which were increased following asthma-induced upregulation of autophagy. Vitamin D improved asthma-induced lung tissue injury by suppressing autophagy via regulation of HIF-1α/Notch1 signaling in vivo.

Small Animal Models of Respiratory Viral Infection Related to Asthma

Respiratory viral infections are strongly associated with asthma exacerbations. Rhinovirus is most frequently-detected pathogen; followed by respiratory syncytial virus; metapneumovirus; parainfluenza virus; enterovirus and coronavirus. In addition; viral infection; in combination with genetics; allergen exposure; microbiome and other pathogens; may play a role in asthma development. In particular; asthma development has been linked to wheezing-associated respiratory viral infections in early life. To understand underlying mechanisms of viral-induced airways disease; investigators have studied respiratory viral infections in small animals. This report reviews animal models of human respiratory viral infection employing mice; rats; guinea pigs; hamsters and ferrets. Investigators have modeled asthma exacerbations by infecting mice with allergic airways disease. Asthma development has been modeled by administration of virus to immature animals. Small animal models of respiratory viral infection will identify cell and molecular targets for the treatment of asthma.

Failure of respiratory defenses in the pathogenesis of bacterial pneumonia of cattle

The respiratory system is well defended against inhaled bacteria by a dynamic system of interacting layers, including mucociliary clearance, host defense factors including antimicrobial peptides in the epithelial lining fluid, proinflammatory responses of the respiratory epithelium, resident alveolar macrophages, and recruited neutrophils and monocytes. Nevertheless, these manifold defenses are susceptible to failure as a result of stress, glucocorticoids, viral infections, abrupt exposure to cold air, and poor air quality. When some of these defenses fail, the lung can be colonized by bacterial pathogens that are equipped to evade the remaining defenses, resulting in the development of pneumonia. This review considers the mechanisms by which these predisposing factors compromise the defenses of the lung, with a focus on the development of bacterial pneumonia in cattle and supplemented with advances based on mouse models and the study of human disease. Deepening our understanding of how the respiratory defenses fail is expected to lead to interventions that restore these dynamic immune responses and prevent disease.