RESUMO
Cathepsin S (CatS) is upregulated in the lungs of patients with cystic fibrosis (CF). However, its role in CF lung disease pathogenesis remains unclear.In this study, ß-epithelial Na+ channel-overexpressing transgenic (ßENaC-Tg) mice, a model of CF-like lung disease, were crossed with CatS null (CatS-/-) mice or treated with the CatS inhibitor VBY-999.Levels of active CatS were elevated in the lungs of ßENaC-Tg mice compared with wild-type (WT) littermates. CatS-/-ßENaC-Tg mice exhibited decreased pulmonary inflammation, mucus obstruction and structural lung damage compared with ßENaC-Tg mice. Pharmacological inhibition of CatS resulted in a significant decrease in pulmonary inflammation, lung damage and mucus plugging in the lungs of ßENaC-Tg mice. In addition, instillation of CatS into the lungs of WT mice resulted in inflammation, lung remodelling and upregulation of mucin expression. Inhibition of the CatS target, protease-activated receptor 2 (PAR2), in ßENaC-Tg mice resulted in a reduction in airway inflammation and mucin expression, indicating a role for this receptor in CatS-induced lung pathology.Our data indicate an important role for CatS in the pathogenesis of CF-like lung disease mediated in part by PAR2 and highlight CatS as a therapeutic target.
Assuntos
Catepsinas/metabolismo , Fibrose Cística/metabolismo , Muco/metabolismo , Pneumonia/metabolismo , Receptor PAR-2/metabolismo , Obstrução das Vias Respiratórias/metabolismo , Animais , Catepsinas/genética , Modelos Animais de Doenças , Canais Epiteliais de Sódio/genética , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pneumonia/etiologiaRESUMO
Although commonly fatal, bacterial pericarditis is often not diagnosed antemortem due to its infrequent occurrence and fulminant course. Historically, Streptococcus pneumoniae has been the most common cause of bacterial pericarditis. Over the past 70 years, however, it has become largely eliminated and now occurs almost exclusively in immunocompromised individuals with a preceding primary site of infection. Herein, we present a case of primary S. pneumoniae pericarditis that developed over the course of 3 to 4 weeks in an immunocompetent 45-year-old man. The patient, who developed cardiac tamponade shortly after admission, experienced a rapid resolution of symptoms following pericardial drainage and initiation of antibiotics.