Respiratory and Cardiovascular Effects in COPD

The age-related impairment of innate immunity and antioxidant defenses likely impacts on development and disease progression of chronic obstructive pulmonary disease, COPD. It has been suggested that aging-related declines in function are accelerated in COPD due to recurrent cycles of inflammation, tissue injury and repair, associated with long-term exposure to cigarette smoke or other airway irritants. Here, the investigators aim to follow up on previous observations of impaired antioxidant responses in the lung of COPD patients, to establish the extent to which this reflects an accelerated aging phenotype, to characterize the molecular mechanisms resulting in this functional deficiency. The proposed studies will employ well-characterized patients with COPD of varying severity and smoking habits, as well as carefully age and smoking history-matched controls. Accelerated aging within the COPD lung will be assessed in endobronchial mucosal biopsies and airway macrophages by assessment of established senescence markers using immunohistochemical, biochemical and PCR-based methods. These markers of tissue age will then be related to the functional activation of transcription factors, known to be induced by oxidative stress and related to cytoprotection such as Nrf2 and AP1. The investigators will also examine whether COPD is associated with an enhanced secretion of inflammatory mediators from senescent cells, consistent with the accelerated aging paradigm and establish how this influences cell function. Deficiencies in metal handling, antioxidant defenses and diminished airway innate immune defenses at the air-lung interface will be assessed. The aim is to identify biomarkers for the risk of rapid lung function deterioration in COPD patients.