Ferritinophagy: molecular mechanisms and its crosstalk with ferroptosis in chronic respiratory diseases.

Ferritinophagy, a selective autophagic process mediated by nuclear receptor coactivator 4 (NCOA4), plays a central role in maintaining cellular iron homeostasis by degrading ferritin and releasing stored iron. Under physiological conditions, this process dynamically regulates iron storage and utilization, thereby preventing both iron deficiency and iron overload. However, under pathological conditions such as chronic inflammation, oxidative stress, and harmful environmental exposures, aberrant activation of ferritinophagy leads to excessive ferritin degradation and abnormal expansion of the cytosolic labile iron pool. This, in turn, drives the accumulation of iron-dependent reactive oxygen species and lipid peroxidation, lowering the threshold for ferroptosis initiation, exacerbating tissue injury, and promoting disease progression. Thus, the pathological significance of ferritinophagy lies not only in iron mobilization itself but also in its close coupling with ferroptosis. This "ferritinophagy-ferroptosis axis" has emerged as a key framework for understanding the link between iron dysregulation and disease pathogenesis. In recent years, increasing evidence has shown that this axis is repeatedly activated in various chronic respiratory diseases (CRDs), where it exerts a pivotal role in disease onset and progression. This review systematically summarizes the molecular mechanisms of NCOA4-mediated ferritinophagy and highlights the potential pathogenic role of the ferritinophagy-ferroptosis axis in different CRDs, aiming to provide a theoretical basis for identifying novel therapeutic strategies and intervention targets.