The role of macrophages polarization in sepsis-induced acute lung injury

Abstract

Sepsis presents as a severe infectious disease frequently documented in clinical settings. Characterized by its systemic inflammatory response syndrome, sepsis has the potential to trigger multi-organ dysfunction and can escalate to becoming life-threatening. A common fallout from sepsis is acute lung injury (ALI), which often progresses to acute respiratory distress syndrome (ARDS). Macrophages, due to their significant role in the immune system, are receiving increased attention in clinical studies. Macrophage polarization is a process that hinges on an intricate regulatory network influenced by a myriad of signaling molecules, transcription factors, epigenetic modifications, and metabolic reprogramming. In this review, our primary focus is on the classically activated macrophages (M1-like) and alternatively activated macrophages (M2-like) as the two paramount phenotypes instrumental in sepsis’ host immune response. An imbalance between M1-like and M2-like macrophages can precipitate the onset and exacerbate the progression of sepsis. This review provides a comprehensive understanding of the interplay between macrophage polarization and sepsis-induced acute lung injury (SALI) and elaborates on the intervention strategy that centers around the crucial process of macrophage polarization.

BAP31 Promotes Adhesion Between Endothelial Cells and Macrophages Through the NF-κB Signaling Pathway in Sepsis

“…Different phenotypes are the hallmarks of macrophages which represent two terminals of macrophage activation during inflammation. 21 In this study, we wanted to understand whether BAP31 can affect the phenotype and function of macrophages upon binding to EC. As we know, M1 macrophages express surface molecular markers, such as CD80 and CD86, and secrete pro-inflammatory cytokines like IL-1β and TNF-α; while M2 macrophages express surface molecular markers, such as CD163 and CD206, and secrete cytokines, like IL-10 and TGF-β, which involved in anti-inflammatory reactions and tissue remodeling.…”

Roles of Macrophages and Endothelial Cells and Their Crosstalk in Acute Lung Injury

“…M1 macrophages are primarily associated with pro-inflammatory responses and play a pivotal role in host defense against invading pathogens [ 22 , 29 , 54 , 58 , 59 ]. They are characterized by their capacity to produce pro-inflammatory cytokines and generate reactive oxygen species, thereby aiding in the elimination of microorganisms [ 23 , 55 , 60 ]. In the context of ALI, M1 macrophages are instrumental in initiating the immune response and contributing to tissue damage during the early stages of the condition [ 17 , 29 , 60 ].…”

“…The process of macrophage polarization in ALI is dynamic and heavily influenced by various factors present within the lung microenvironment [ 17 , 18 , 30 , 60 , 62 ]. The delicate balance between M1 and M2 polarization states plays a pivotal role in determining the overall inflammatory response and, consequently, the progression or resolution of ALI [ 31 , 33 , 35 , 55 , 57 ].…”

Polymeric Particle BAM15 Targeting Macrophages Attenuates the Severity of LPS-Induced Sepsis: A Proof of Concept for Specific Immune Cell-Targeted Therapy

“…Over the past decade, regulating macrophage polarization has become a potential strategy in the treatment of immune-related diseases, such as sepsis, autoimmunity, and cancer. Blockage of pro-inflammatory M1 macrophage polarization attenuates overwhelming inflammation in severe infection and autoimmune diseases [ 2 , 4 ], while reduction in anti-inflammatory M2 macrophage polarization enhances inflammatory responses that are necessary for controlling malignant cells [ 5 , 6 ]. The polarization between M1 and M2 macrophages requires different energy sources and metabolic pathways.…”