title: Myofibroblasts.
abstract: Myofibroblasts are activated in response to tissue injury with the primary task to repair lost or damaged extracellular matrix. Enhanced collagen secretion and subsequent contraction - scarring - are part of the normal wound healing response and crucial to restore tissue integrity. Due to myofibroblasts ability to repair but not regenerate, accumulation of scar tissue is always associated with reduced organ performance. This is a fair price to pay by the body for not falling apart. Whereas myofibroblasts typically vanish after successful repair, dysregulation of the normal repair process can lead to persistent myofibroblast activation, for instance by chronic inflammation or mechanical stress in the tissue. Excessive repair leads to the accumulation of stiff collagenous ECM contractures - fibrosis - with dramatic consequences for organ function. The clinical need to terminate detrimental myofibroblast activities has stimulated researchers to answer a number of essential questions: where do myofibroblasts come from, what are the factors leading to their activation, how do we discriminate myofibroblasts from other cells, what is the molecular basis for their contractile activity, and how can we stop or at least control them? This article reviews the current state of the myofibroblast literature by emphasizing their role in ocular repair and fibrosis. It appears that although the eye is quite an extraordinary organ, ocular myofibroblasts behave or misbehave just like their siblings in other organs.
authors.affiliation: Laboratory of Tissue Repair and Regeneration, Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, 150 College Street, FitzGerald Building, Room 234, Toronto, M5S 3E2 Ontario, Canada. Electronic address: boris.hinz@utoronto.ca.
authors.forename: Boris
authors.initials: B
authors.lastname: Hinz
mesh_terms: D000199:Actins / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D003094:Collagen / Q000378:metabolism; D005131:Eye Injuries / Q000503:physiopathology*; D005347:Fibroblasts / Q000166:cytology; D005355:Fibrosis / Q000503:physiopathology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000502:physiology; D058628:Myofibroblasts / Q000166:cytology / Q000502:physiology*; D014945:Wound Healing / Q000502:physiology
chemical_list: D000199:Actins; D036341:Intercellular Signaling Peptides and Proteins; D003094:Collagen
keywords: Contraction; Contracture; Fibrosis; Inflammation; Scar; Stress fiber; Transforming growth factor beta; α-smooth muscle actin