Lung macrophages utilize unique cathepsin K-dependent phagosomal machinery to degrade intracellular collagen.

ABSTRACT: Resident tissue macrophages are organ-specialized phagocytes responsible for the maintenance and protection of tissue homeostasis. It is well established that tissue diversity is reflected by the heterogeneity of resident tissue macrophage origin and phenotype. However, much less is known about tissue-specific phagocytic and proteolytic macrophage functions. Here, using a quantitative proteomics approach, we identify cathepsins as key determinants of phagosome maturation in primary peritoneum-, lung-, and brain-resident macrophages. The data further uncover cathepsin K (CtsK) as a molecular marker for lung phagosomes required for intracellular protein and collagen degradation. Pharmacological blockade of CtsK activity diminished phagosomal proteolysis and collagenolysis in lung-resident ma

SUBMITTER: Fabrik I 

PROVIDER: S-EPMC9877437 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature