Lung ageing and COPD: is there a role for ageing in abnormal tissue repair?

Abstract

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide, with increasing prevalence, in particular in the elderly. COPD is characterised by abnormal tissue repair resulting in (small) airways disease and emphysema. There is accumulating evidence that ageing hallmarks are prominent features of COPD. These ageing hallmarks have been described in different subsets of COPD patients, in different lung compartments and also in a variety of cell types, and thus might contribute to different COPD phenotypes. A better understanding of the main differences and similarities between normal lung ageing and the pathology of COPD may improve our understanding of the mechanisms driving COPD pathology, in particular in those patients that develop the most severe form of COPD at a relatively young age, i.e. severe early-onset COPD patients.In this review, after introducing the main concepts of lung ageing and COPD pathology, we focus on the role of (abnormal) ageing in lung remodelling and repair in COPD. We discuss the current evidence for the involvement of ageing hallmarks in these pathological features of COPD. We also highlight potential novel treatment strategies and opportunities for future research based on our current knowledge of abnormal lung ageing in COPD.

FIGURE 1

Pathological changes in chronic obstructive pulmonary disease. a) Characteristic picture of airways changes, with increase of goblet cells, a thickened airway wall with some adventitial inflammation, and a small lymphoid follicle at the left upper side. Emphysema is hardly present here. Haematoxylin and eosin, ×200 magnification, scale bar=200 μm. Inset shows magnification of part of the airway with a lymphoid follicle; scale bar=50 μm. b) At the left, an almost longitudinal cross-section of a small airway, and at the right, severe parenchymal destruction by emphysema. Haematoxylin and eosin, ×100 magnification, scale bar=500 μm.