Macrophage function and polarization in cardiovascular disease: a role of estrogen signaling?

Macrophages are plastic and versatile cells adapting their function/phenotype to the microenvironment. Distinct macrophage subpopulations with different functions, including classically (M1) and (M2) activated macrophages, have been described. Reciprocal skewing of macrophage polarization between the M1 and M2 state is a process modulated by transcription factors, such as the nuclear peroxisome proliferator-activated receptors. However, whether the estrogen/estrogen receptor pathways control the balance between M1/M2 macrophages is only partially understood. Estrogen-dependent effects on the macrophage system may be regarded as potential targets of pharmacological approaches to protect postmenopausal women from the elevated risk of cardiovascular disease.