Fibrocytes: a unique cell population implicated in wound healing

Following tissue damage, host wound healing ensues. This process requires an elaborate interplay between numerous cell types which orchestrate a series of regulated and overlapping events. These events include the initiation of an antigen-specific host immune response, blood vessel formation, as well as the production of critical extracellular matrix molecules, cytokines and growth factors which mediate tissue repair and wound closure. Connective tissue fibroblasts are considered essential for successful wound healing; however, their origin remains a mystery. A unique cell population, known as fibrocytes, has been identified and characterized. One of the unique features of these blood-borne cells is their ability to home to sites of tissue damage. This article reviews the identification and characterization of fibrocytes, summarizes the potential role of fibrocytes in the numerous steps of the wound-healing process and highlights the potential role of fibrocytes in fibrotic disease pathogenesis.Received 25 November 2002; received after revision 31 December 2002; accepted 16 January 2003