Extracellular vesicles in ciliary signalling

Primary cilia are tiny cellular protrusions deeply involved in intercellular communication. Initially misjudged as a rudiment of motile cilia, it turned out that the primary cilium functions as the cell’s antenna mediating signals which are indispensable for proper human development and homeostasis. Ciliary dysfunction results in severe human diseases collectively referred to as ciliopathies. Originally, ciliopathies were considered to be rare diseases, but the number of diseases identified as or assumed to be ciliopathies is permanently rising. Even common diseases such as cancer or neurodegenerative diseases are considered to be associated with primary cilia. Remarkably, cilia-mediated signalling is associated with extracellular vesicles. In this review, we summarise the current knowledge about the relationship between primary cilia and extracellular vesicles and discuss the role of this relationship in the development of human diseases.