, according to the cell variety, mitochondria may also be involved in other metabolic processes, such as CYP1 Molecular Weight calcium and apoptosis signaling (2). Considering their accepted endosymbiotic origin, mitochondria have their own transcriptional machinery, proteome, and DNA (mitochondrial DNA [mtDNA]), which makes them semi-autonomous organelles regulating their homeostasis by autophagy, fusion, and fission (six). Through homeostasis, mitochondria have vital roles in lung function. Mitochondria quantity and intracellular organization can differ in an energy-dependent kind for distinct types of airway epithelial cells (7). Mitochondria can regulate surfactant production, cellular senescence, mucociliary function, and mucus secretion (7). Mitochondria are also crucial in pulmonary immunometabolism and immune cell response, like in alveolar macrophages (8). Appreciation for mitochondrial noncanonical functions has improved our know-how of theirSpecialty section: This short article was submitted to Inflammation, a section in the journal Frontiers in Immunology Received: 23 September 2021 Accepted: 29 October 2021 Published: 23 November 2021 Citation: Caldeira DAF, Weiss DJ, Rocco PRM, Silva PL and Cruz FF (2021) Mitochondria in Focus: From Function to Therapeutic Strategies in Chronic Lung Illnesses. Front. Immunol. 12:782074. doi: 10.3389/fimmu.2021.Frontiers in Immunology | frontiersin.orgNovember 2021 | Volume 12 | ArticleCaldeira et al.Mitochondria and Chronic Lung Diseasesrole in pathophysiologic processes, including chronic lung illnesses for example chronic obstructive pulmonary illness (COPD) (Figure 1), idiopathic pulmonary fibrosis (IPF) (Figure 2), and asthma (Figure 3) (92). The centrality of mitochondrial dysfunction inside the context of chronic MAP4K1/HPK1 Species respiratory diseases has been studied extensively in ailments that have an effect on the trachea, bronchi, bronchioles (13, 14), alveoli (15, 16), and interstitium (17, 18). Mitochondrial dysfunction alters cell bioenergetics and hinders lung recovery following an insult (19). As a result, highlighting the importance and challenges of taking a look at mitochondria as a brand new target for therapeutic techniques in chronic lung diseases is essential (2022). This review summarizes some mitochondrial physiologic and pathologic processes, also as therapeutic methods for chronic lung ailments contemplating mitochondria because the central point.MITOCHONDRIAL MORPHOLOGYStructurally, mitochondria differ from other organelles in that their internal compartment (matrix) is kept aside from the cell cytoplasm by means of inner and outer membranes, separated by an intermembrane space, and all of those components play a fundamental part in their biochemical reactions (23). The conserved inner membrane ultrastructure consists of invaginations or cristae exactly where OX-PHOS enzymes, which are fundamental to mitochondrial functionality, are situated (1, 24). In addition, because of their lipid composition, modest size, and partial transcriptional independence in the nucleus, mitochondria are exceptionally dynamic organelles (25). In response to pathophysiologic adjustments, mitochondria can alter structurally and numerically by means of modifications within the behavior of their protein machinery (26). In major sort II alveolar epithelial cells (AECII) in patients with COPD, abnormalities in the mitochondrial morphology have been reported, like loss of cristae and swollen and fragmented mitochondria (16, 27, 28). In vitro long-term exposure to cigarette smoke extract (CSE) in cultured huma