Characterization of the MMP/TIMP Imbalance and Collagen Production Induced by IL-1β or TNF-α Release from Human Hepatic Stellate Cells

Abstract

Inflammation has an important role in the development of liver fibrosis in general and the activation of hepatic stellate cells (HSCs) in particular. It is known that HSCs are themselves able to produce cytokines and chemokines, and that this production may be a key event in the initiation of fibrogenesis. However, the direct involvement of cytokines and chemokines in HSC (self-)activation remains uncertain. In this study, the effects of pro-inflammatory cytokines IL-1α and β, TNF-α, and IL-8 on the activation state of HSCs were examined, in comparison to the pro-fibrogenic mediator TGF-β1. LX-2 cells were stimulated for 24 or 48 hours with recombinant human form of the pro-inflammatory cytokines IL-1α and β, TNF-α, and IL-8, and also the pro-fibrogenic mediator TGF-β1. Two drugs were also evaluated, the anti-TNF-α monoclonal antibody infliximab and the IL-1 receptor antagonist anakinra, regarding their inhibitory effects. In LX-2 human HSC, treatment with TGF-β1 are associated with downregulation of the metalloproteinase (MMP)-1 and MMP-3, with upregulation of tissue inhibitor of metalloproteinase (TIMP)-1, collagen type I α1, collagen type IV α1, α-SMA, endothelin-1 and PDGF-BB. Cytokines and chemokines expression were found to be downregulated, excepting IL-6. In contrast, we observed that LX-2 exposure to IL-1, TNF-α and IL-8 can reverse the phenotype of pro-fibrogenic activated cells. Indeed, MMP-1, MMP-3 and MMP-9 were found elevated, associated with downregulation of α-SMA and/or PDGF-BB, and a greater expression of IL-1β, IL-6, IL-8, CXCL1 and CCL2. Lastly, we found that infliximab and anakinra successfully inhibits effects of TNF-α and IL-1 respectively in LX-2 cells. Infliximab and anakinra may be of value in preclinical trials in chronic liver disease. Overall, our results suggest that (i) pro-inflammatory mediators exert complex effects in HSCs via an MMP/TIMP imbalance, and (ii) targeting IL-1 signaling may be a potentially valuable therapeutic strategy in chronic liver diseases.

Ursolic acid ameliorates CCl4‐induced liver fibrosis through the NOXs/ROS pathway

“…Activated HSCs lead to liver metabolism reprogramming, increased autophagy and serious damage to parenchymal cells. This results in loss of the retinoids and enhanced contractility in HSCs, which releases growth factors and inflammatory signal factors in the liver microenvironment, liberates large amounts of extracellular matrix (ECM), and lead to an imbalance of matrix metalloproteinases (MMPs) and matrix inhibitor of metalloproteinase (TIMPs) (Lee et al, ; Robert, Gicquel, Bodin, Lagente, & Boichot, ). HCs and KCs also play an important role in liver fibrosis.…”

Cucurbitacin‐B attenuates CCl4‐induced hepatic fibrosis in mice through inhibition of STAT‐3

“…The potent proinflammatory cytokine TNF‐α is released by HSCs in response to the profibrogenic mediator TGF‐β. It initiates inflammatory responses through stimulating secretion of other proinflammatory cytokines, such as IL‐1β …”

IL-17 and TNF-α co-operation contributes to the proinflammatory response of hepatic stellate cells

“…Another study showed that IL-17 alone had a very weak or no effect on collagen type I α1 and TIMP1 expression [15]. In addition, in LX-2 cells, TNF-α stimulation up-regulated MMP1, MMP3 and MMP9 expression, whereas collagen type I α1, TIMP1 and MMP2 expressions were unchanged [24,25]. In addition, in LX-2 cells, TNF-α stimulation up-regulated MMP1, MMP3 and MMP9 expression, whereas collagen type I α1, TIMP1 and MMP2 expressions were unchanged [24,25].…”