Semaphorins in health and disease

Cell-cell communication is pivotal to guide embryo development, as well as to maintain adult tissues homeostasis\r\nand control immune response. Among extracellular factors responsible for this function, are the\r\nSemaphorins, a broad family of around 20 different molecular cues conserved in evolution and widely expressed\r\nin all tissues. The signaling cascades initiated by semaphorins depend on a family of conserved receptors, called\r\nPlexins, and on several additional molecules found in the receptor complexes. Moreover, multiple intracellular\r\npathways have been described to act downstream of semaphorins, highlighting significant diversity in the signaling\r\ncascades controlled by this family. Notably, semaphorin expression is altered in many human diseases,\r\nsuch as immunopathologies, neurodegenerative diseases and cancer. This underscores the importance of semaphorins\r\nas regulatory factors in the tissue microenvironment and has prompted growing interest for assessing\r\ntheir potential relevance in medicine. This review article surveys the main contexts in which semaphorins have\r\nbeen found to regulate developing and healthy adult tissues, and the signaling cascades implicated in these\r\nfunctions. Vis a vis, we will highlight the main pathological processes in which semaphorins are thought to have\r\na role thereof.