Reduction in Rubicon by cigarette smoke is associated with impaired phagocytosis and occurs through lysosomal degradation pathway

Background A common feature of COPD is a defective lung macrophage phagocytic capacity that can contribute to chronic lung inflammation and infection. The precise mechanisms remain incompletely understood, although cigarette smoke is a known contributor. We previously showed deficiency of the LC3-associated phagocytosis (LAP) regulator, Rubicon, in macrophages from COPD subjects and in response to cigarette smoke. The current study investigated the molecular basis by which cigarette smoke extract (CSE) reduces Rubicon in THP-1, alveolar and blood monocyte-derived macrophages, and the relationship between Rubicon deficiency and CSE-impaired phagocytosis. Methodology Phagocytic capacity of CSE-treated macrophages was measured by flow cytometry, Rubicon expression by Western blot and real time polymerase chain reaction, and autophagic-flux by LC3 and p62 levels. The effect of CSE on Rubicon degradation was determined using cycloheximide inhibition and Rubicon protein synthesis and half-life assessment. Results Phagocytosis was significantly impaired in CSE-exposed macrophages and strongly correlated with Rubicon expression. CSE-impaired autophagy, accelerated Rubicon degradation, and reduced its half-life. Lysosomal protease inhibitors, but not proteasome inhibitors, attenuated this effect. Autophagy induction did not significantly affect Rubicon expression. Conclusions CSE decreases Rubicon through the lysosomal degradation pathway. Rubicon degradation and/or LAP impairment may contribute to dysregulated phagocytosis perpetuated by CSE..

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:23

Enthalten in:

Clinical and experimental medicine - 23(2023), 7 vom: 13. Juni, Seite 4041-4055

Sprache:

Englisch

Beteiligte Personen:

Asare, Patrick F. [VerfasserIn]
Hurtado, Plinio R. [VerfasserIn]
Tran, Hai B. [VerfasserIn]
Perkins, Griffith B. [VerfasserIn]
Roscioli, Eugene [VerfasserIn]
Hodge, Sandra [VerfasserIn]

Links:

Volltext [lizenzpflichtig]

Themen:

Autophagy
Inflammation
LC3-associated phagocytosis (LAP)
Phagocytosis
Rubicon

Anmerkungen:

© The Author(s), under exclusive licence to Springer Nature Switzerland AG 2023

doi:

10.1007/s10238-023-01105-1

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

SPR053585186