Novel insights into the pathological features of COPD: Focus on oxidative stress and mitophagy

Chronic airway obstructive pulmonary disease (COPD) is a preventable and curable disease characterised by persistent airflow limitation. It is characterised by chronic bronchitis and/or emphysema, and its aetiology is related to various factors such as smoking and infectious factors, and so forth. The pathogenesis is complex and prone to frequent exacerbations, and the prognosis of acute exacerbations of COPD is often poor. As a crucial component of the innate immune system, lung macrophages significantly influence the onset and progression of COPD. When macrophage mitochondria become dysfunctional, many macrophage functions (e.g., phagocytosis, cytokine secretion, chemotaxis, etc.) change. The aim of this paper is to describe the three major pathological features of COPD (oxidative stress imbalance, macrophage polarisation and mitochondrial membrane potential [MMP] production and mitochondrial autophagy), to describe in detail the mechanism of mitochondrial autophagy pathway and its association with oxidative stress and macrophage polarisation and to emphasise the role of macrophage mitochondrial reactive oxygen species (mROS) in COPD, with the aim of providing ideas and directions for subsequent studies.