. Author manuscript; available in PMC: 2021 Feb 27.

Published in final edited form as: Nat Rev Rheumatol. 2019 Dec 2;16(1):11–31. doi: 10.1038/s41584-019-0324-5

Table 1 |.

Characteristics of fibroblasts and myofibroblasts

Characteristic	Fibroblasts	Myofibroblasts	Refs
Distribution	Ubiquitous in connective tissues	Damaged tissues, fibrosis and cancer	²⁹⁹
Morphology	Large, flat and elongated (spindleshaped) cells that contain cortical actin microfilaments	Smooth muscle-like cells that contain contractile actin-myosin bundles and have specialized adhesion structures	¹⁵
Origin	Mesoderm	Tissue-resident fibroblasts, epithelial cells, endothelial cells, pericytes and mesenchymal stem cells	¹⁷
Functions	Maintain ECM homeostasis by secreting ECM proteins and matrix-degrading enzymes; proliferate and migrate into the wound bed to deposit granulation tissue during tissue repair	Produce large amounts of type I collagen during tissue repair; contract wound margins to facilitate re-epithelialization and restoration of tissue integrity; their persistence contributes to the pathogenesis of fibrosis and cancer	^1,30,300
Molecular markers	Vimentin⁺α-SMA⁻ cells that secrete ECM proteins and produce MMPs and TIMPs	Fibronectin ED-A⁺α-SMA⁺ cells that synthesize type I collagen and produce matrix crosslinking enzymes	⁹⁸
Proliferative capacity	High (during wound healing)	Low	³⁰¹
Metabolic activity	Low	High (aerobic glycolysis)	¹⁶⁸
Biomechanical activity	Low	High (hypercontractile phenotype)	³⁰²
Apoptosis sensitivity	Low	High (primed for death)	⁸⁶

ECM, extracellular matrix; fibronectin ED-A, fibronectin extra domain A; MMP, matrix metalloproteinase; TIMP, tissue inhibitor of metalloproteinase; α-SMA, α-smooth muscle actin.