Table 1.

Characteristics of quiescent and activated PSC phenotypes.

	Quiescent PSCs	Activated PSCs
Vitamin A lipid droplets	Present	Absent
α Smooth muscle actin	Absent	Present
Proliferation	Limited	Increased
Migration	Limited	Increased
Extracellular matrix production	Limited	Increased
Matrix metalloproteinases (MMPs) and tissue inhibitors of matrix proteinases (TIMPs)	Complement of MMPs and TIMPs to maintain normal ECM turnover	Change in types of MMPs and TIMPs to facilitate ECM deposition
Production of cytokines	Limited	Increased (PDGF, TGFβ, CTGF, IL1, IL6, IL15)
Capacity for phagocytosis	Absent	Present
Proteomic analyses	Basal protein expression	Differential expression of proteins related to the cell cytoskeleton, cell metabolism, motility, growth and invasion