Pericyte Secretome.

The role of pericytes seems to extend beyond their known function in angiogenesis, fibrosis and wound healing, blood-brain barrier maintenance, and blood flow regulation. More and more data are currently accumulating indicating that pericytes, uniquely positioned at the interface between blood and parenchyma, secrete a large plethora of different molecules in response to microenvironmental changes. Their secretome is tissue-specific and stimulus-specific and includes pro- and anti-inflammatory factors, growth factors, and extracellular matrix as well as microvesicles suggesting the important role of pericytes in the regulation of immune response and immune evasion of tumors. However, the angiogenic and trophic secretome of pericytes indicates that their secretome plays a role in physiological homeostasis but possibly also in disease progression or could be exploited for regenerative processes in the future. This book chapter summarizes the current data on the secretory properties of pericytes from different tissues in response to certain pathological stimuli such as inflammatory stimuli, hypoxia, high glucose, and others and thereby aims to provide insights into the possible role of pericytes in these conditions.