Exosomal miR-30d-5p of neutrophils induces M1 macrophage polarization and primes macrophage pyroptosis in sepsis-related acute lung injury

Abstract

Background Polymorphonuclear neutrophils (PMNs) play an important role in sepsis-related acute lung injury (ALI). Accumulating evidence suggests PMN-derived exosomes as a new subcellular entity acting as a fundamental link between PMN-driven inflammation and tissue damage. However, the role of PMN-derived exosomes in sepsis-related ALI and the underlying mechanisms remains unclear. Methods Tumor necrosis factor-α (TNF-α), a key regulator of innate immunity in sepsis-related ALI, was used to stimulate PMNs from healthy C57BL/6J mice in vitro. Exosomes isolated from the supernatant were injected to C57BL/6J wild-type mice intraperitoneally (i.p.) and then examined for lung inflammation, macrophage (Mϕ) polarization and pyroptosis. In vitro co-culture system was applied where the mouse Raw264.7 macrophages or bone marrow-derived macrophages (BMDMs) were co-cultured with PMN-derived exosomes to further confirm the results of in vivo animal study and explore the potential mechanisms involved. Results Exosomes released by TNF-α-stimulated PMNs (TNF-Exo) promoted M1 macrophage activation after in vivo i.p. injection or in vitro co-culture. In addition, TNF-Exo primed macrophage for pyroptosis by upregulating NOD-like receptor 3 (NLRP3) inflammasome expression through nuclear factor κB (NF-κB) signaling pathway. Mechanistic studies demonstrated that miR-30d-5p mediated the function of TNF-Exo by targeting suppressor of cytokine signaling (SOCS-1) and sirtuin 1 (SIRT1) in macrophages. Furthermore, intravenous administration of miR-30d-5p inhibitors significantly decreased TNF-Exo or cecal ligation and puncture (CLP)-induced M1 macrophage activation and macrophage death in the lung, as well as the histological lesions. Conclusions The present study demonstrated that exosomal miR-30d-5p from PMNs contributed to sepsis-related ALI by inducing M1 macrophage polarization and priming macrophage pyroptosis through activating NF-κB signaling. These findings suggest a novel mechanism of PMN-Mϕ interaction in sepsis-related ALI, which may provide new therapeutic strategies in sepsis patients.

Trans-anethole ameliorates lipopolysaccharide-induced acute liver inflammation in broilers via inhibiting NF-κB signaling pathway

“…During immune response processes activated by bacterial stimuli, the macrophages and monocytes are in charge of secreting these inflammatory cytokines ( Cavaillon, 2018 ). Among these cytokines, TNF-α is the prototype of proinflammatory cytokines contributing to many pathogenic processes, such as periodontitis and acute lung injury ( ALI ) ( Jiao et al., 2021 ). Similarly, IL-1β is the most studied member of IL-1 family released from macrophages and IL-6 is one of the major regulators in acute phase reaction ( Iannarelli et al., 2018 ).…”

Extracellular Vesicle/Macrophage Axis: Potential Targets for Inflammatory Disease Intervention

“…In addition to EVs in circulating blood, EVs derived from neutrophils or lung epithelial cells are also involved in the regulation of acute lung injury. EV-miR-30d-5p derived from neutrophils induces M1-like polarization of macrophages in sepsis-related acute lung injury ( 37 ). Moon et al.…”

Epithelial‑derived exosomes promote M2 macrophage polarization via Notch2/SOCS1 during mechanical ventilation

“…BMDM or Raw264.7 macrophages were seeded in 6-well plates (5.0×10 5 cells/well), grown to 70-80% confluence, and divided into the following groups: i) The non-CS-exo (incubated with exosomes, which were isolated from non-CS group medium); and ii) the CS-exo group (incubated with exosomes isolated from CS group medium). The cells were treated with non-CS-exo or CS-exo (100 µ g/ml), as previously described ( 28 ) for 12 h.…”

“…To explore the function of exosome in vivo , a total of 51 male C57BL/6 mice were randomly divided into three groups as follows: The control (ctrl), non-CS-exo and CS-exo. The mice were administrated with non-CS-exo or CS-exo (300 µ g/mouse) ( 28 ) through a tracheal cannula. After 24 h, the animals were sacrificed with an overdose of 2% sodium pentobarbital, and the lung tissues were then collected.…”

“…Exosomal miRNAs can mediate inter-cellular communications between several types of cells, which have been reported to influence biological pathways and further alter cellular functions ( 27 ). Exosomal miR-30d-5p-derived from polymorphonuclear neutrophil (PMN)-induced M1 macrophage polarization to promote sepsis-related ALI ( 28 ). Alveolar EC-derived exosomal miR-92a-3p has also been shown to activate macrophages by regulating the NF-kB signaling pathway and suppressing PTEN ( 29 ).…”