Macrophage polarization pathways

Macrophage polarization pathways represent the complex signaling networks that dictate the functional plasticity of macrophages in response to environmental stimuli [PMID: 24445666]. Macrophages can be polarized into two main phenotypes: the classically activated M1 phenotype, which is pro-inflammatory and microbicidal, and the alternatively activated M2 phenotype, which promotes anti-inflammatory responses and tissue repair [PMID: 25870903]. This process is regulated by key transcription factors such as STAT1 and NF-κB for M1, and STAT6, STAT3, and PPARγ for M2 [PMID: 25870903]. In many diseases, an imbalance in polarization occurs; for example, tumor-associated macrophages (TAMs) often adopt an M2-like state that supports tumor growth and suppresses the immune system [PMID: 28263170]. Therapeutic strategies aim to modulate these pathways to re-polarize macrophages, such as using CSF1R inhibitors or TLR agonists to convert pro-tumoral M2 macrophages into anti-tumoral M1 cells [PMID: 31015324]. Because Macrophage polarization pathways refers to a biological process rather than a single protein, it is considered a pathway-level target rather than a discrete molecular target.

Other names

M1/M2 polarizationMacrophage activation pathwaysMacrophage phenotypic switching

Modulation of intracellular signaling cascades (e.g., JAK/STAT, NF-kB, PI3K) and surface receptors (e.g., TLRs, CSF1R) to shift macrophage functional states between pro-inflammatory (M1) and anti-inflammatory/pro-repair (M2) phenotypes.