Mechanisms of the alternative activation of macrophages and non-coding RNAs in the development of radiation-induced lung fibrosis

Figure 1 Non-coding RNAs regulation of macrophage polarization in radiation-induced lung fibrosis. Radiation pneumonitis develops approximately 3 mo after ionizing radiation, resulting from the accumulation of M1 macrophages. Six to twelve months after ionizing radiation (IR) the accumulation of M2 macrophages activates myofibroblast differentiation, resulting in a fibrotic microenvironment and radiation-induced lung fibrosis (RILF). Non-coding RNAs regulate the pathways involved in RILF, and are temporally regulated through RILF development and progression. ECM: Extracellular matrix. This figure was produced using Servier medical art, available from http://www.servier.com/Powerpoint-image-bank.