Inflammatory Cytokines

Inflammatory cytokines are a group of peptide hormones capable of eliciting endocrine, paracrine and autocrine actions. Cytokines are essential to the development and functioning of both the innate and adaptive immune responses and are secreted by e.g., monocytes and macrophages. The secretion of TNF for example by macrophages in damaged muscle (or by the muscle itself) is thought to lead to the recruitment of satellite cells to the site of damage. Inflammatory cytokines also promote protein degradation and are therefore often referred to as catabolic hormones. To this end, they activate a series of intracellular pathways (e.g., those involving nuclear factor kappa beta (NFĸβ)), which culminate in the degradation of protein (generally via the ubiquitin proteosome pathway), thus yielding amino acids and ATP energy sources as well as heat, which underlies the occurrence of fevers. The breakdown of protein stimulated by inflammatory cytokines is beneficial in acute illness in terms of...