TY - CHAP M1 - Book, Section TI - Fibroblasts in Lung Homeostasis and Disease A1 - Zhou, Yong A1 - Thannickal, Victor J. A2 - Grippi, Michael A. A2 - Elias, Jack A. A2 - Fishman, Jay A. A2 - Kotloff, Robert M. A2 - Pack, Allan I. A2 - Senior, Robert M. A2 - Siegel, Mark D. Y1 - 2015 N1 - T2 - Fishman's Pulmonary Diseases and Disorders, 5e AB - Fibroblasts are the primary cellular source responsible for synthesis and remodeling of the extracellular matrix (ECM). These cells are in communication with the surrounding microenvironment and play a key role in lung homoeostasis. Following lung injury, fibroblasts are activated and undergo myofibroblast differentiation. Myofibroblasts are key effector cells for lung repair following injury. In addition to fibroblasts, perivascular pericytes and mesenchymal stem cells (MSCs) of bone marrow (BM) origins contribute to myofibroblast population. There is evidence that type II alveolar epithelial cells can differentiate into myofibroblasts in vitro through a process known as epithelial–mesenchymal transition (EMT); however, the role of EMT in fibrogenesis in vivo remains controversial. Myofibroblasts express α-smooth muscle actin (α-SMA), develop robust actin filaments (stress fibers), and acquire contractile activity. The function and behavior of myofibroblasts are regulated by both biochemical and physical cues in the surrounding microenvironment. The fate of myofibroblasts is a key determinant of whether an injury–repair response will resolve or progress into fibrosis. Destruction and aberrant remodeling of the ECM is a common feature of many lung diseases, including pulmonary fibrosis, asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. Targeting myofibroblasts and tissue remodeling may provide a novel and effective strategy for treating a number of chronic lung diseases. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1122356487 ER -