Table 1 Characteristics of Fibrolytic Macrophages

Anti-fibrosis↑

Fibrolysis

MMP-1, MMP-2

Degrading collagen

Atherosclerotic plaques

[45]

MMP-14, cathepsin K

Pulmonary fibrosis

[46]

MMP-2, MMP-9

Renal fibrosis

[47]

MMP-13

Liver fibrosis

[48]

ECM uptake

Integrin α2β1

Involved in soluble collagen degradation and phagosome maturation mediated by uPARAP/Endo180 or mannose receptor

In vitro

[49]

Mannose receptor

Binding and internalizing collagen IV and gelatin in a carbohydrate-independent manner

In vitro

[50]

uPARAP (Endo180)

Binding collagen through its Endo180 FNII domain

In vitro

[51]

Mfge8

Binding collagen through its discoidin domains; targeting collagen uptake and digestion by macrophages

Pulmonary fibrosis

[41]

Stabilin-1

A homeostatic scavenger receptor binding ECM osteonectin

Liver fibrosis

[42]

Proresolution cytokine

IL-10

Preventing macrophage production of proinflammatory cytokines; preventing the development of Th1-type and Th2 T-cell responses; promoting regulatory T-cell population

Renal fibrosis

[47]

HGF

Enhancing hepatocyte proliferation after liver injury

Liver fibrosis

[52]

CXCL1

Recruiting collagenase-producing neutrophiles to degrade the ECM

Liver fibrosis

[53]

Profibrosis↓

Profibrotic cytokine

TGF-β1

Regulating fibroblast proliferation, migration, activation and differentiation

Liver fibrosis

[43]

TNF-α

Promoting hepatic stellate cell (fibroblast) survival and activation; upregulating expression of TIMP

Liver fibrosis

[54]

CXCL2 (MIP-2)

Recruiting neutrophiles; promoting fibroblast proliferation

Pulmonary fibrosis

[55]