FIG. 1.

DAMPs released from mitochondria. During cell death, various cellular components are released to the extracellular space or exposed to cell surface. The molecules released from dying cells have immune functions and are involved in inflammatory response. These molecules are called DAMPs. Of note, mitochondria release various mitochondrial components, which are involved in inflammatory responses (mitochondrial DAMPs). Damaged cells caused by trauma or infection may undergo cell death, including necrosis. Under these conditions, the necrotic cells can massively leak intracellular components, including mitochondria-related molecules, whereas it is believed that the release of DAMPs from apoptotic cells is limited. Under these conditions, the cells can leak intracellular components, including mitochondria-related molecules. The released or exposed mitochondrial DAMPs can initiate innate or adaptive immune responses by activating cell surface receptors (e.g., P2X7R or FPRs) or intracellular receptors (e.g., TLR9 or NLRP3) after their internalization into the cells. DAMPs, damage-associated molecular patterns; FPR, formyl peptide receptor; TLR, toll-like receptor. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars