Abstract 97: High mobility group box-1 Promotes Restenosis Via Toll like receptor-4 Signal Pathway

Background: High-mobility group box 1 (HMGB1) is an endogenous molecule released during cell stress and death termed damage-associated molecular patterns (DAMPs). HMGB1 activates the pattern recognition receptor, toll-like receptor 4 (TLR4), and induces sterile inflammation. However, how HMGB1 and TLR4 affect restenosis, the major complication following balloon and stent intervention clinically, remains unknown. We tested the hypothesis that HMGB1 released following acute arterial injury promotes intimal hyperplasia (IH), a hallmark of restenosis, via TLR4 signaling pathway. Methods and Results: Wire injury of the carotid artery in C57BL/6 wild-type (WT) mice significantly increased intima-to-media ratio in 4 weeks. Global deletion of HMGB1 using an inducible knockout mouse strain prevented IH and vessel remodeling. IH decreased by over 50% in WT mice treated with a HMGB1 neutralizing antibody. Of the mouse strains deficient in putative receptors and co-regulator for HMGB1 (TLR4-/-, TLR2-/-, RAGE-/- and CD14-/-), TLR4-/- mice showed the greatest inhibition of IH after injury. Both TLR4 adaptors MYD88 and TRIF synergistically participated in the inflammatory response to vascular injury. HMGB1 antibody-treated mice and TLR4-/- mice showed a marked decrease in monocytic recruitment following injury. Mice with selective depletion of TLR4 from macrophages (TLR4-/--Mø) exhibited similar level of IH inhibition and macrophage infiltration, compared to the global TLR4-/- mice. In vitro, disulfide HMGB1 concentration-dependently promoted smooth muscle cell (SMC) migration and MCP-1/CCR2 expression, which were abolished by treatment with TLR4 inhibitory peptide. Moreover, conditioned media from HMGB1-treated macrophage induced SMC proliferation, which was blunted by blocking TLR4 on macrophage, but not SMCs. Finally, HMGB1 increased cytokine (TNF-α and IL-6), chemokine (MCP-1) and mitogen (PDGF-A) levels in macrophage in a TLR4-dependent manner. Conclusion: These findings demonstrate, for the first time, that HMGB1 released following acute arterial injury promotes restenosis via SMC migration and MCP-1/CCR2 production as well as macrophage-released TNF-α, IL-6, MCP-1 and PDGF-A in SMC through the TLR4-MyD88/TRIF signal cascade.

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TNF-α Activates High-Mobility Group Box 1 - Toll-Like Receptor 4 Signaling Pathway in Human Aortic Endothelial Cells

Cellular Physiology and Biochemistry ◽

10.1159/000445570 ◽

2016 ◽

Vol 38 (6) ◽

pp. 2139-2151 ◽

Cited By ~ 16

Author(s):

Won Seok Yang ◽

Nam Jeong Han ◽

Jin Ju Kim ◽

Mee Jeong Lee ◽

Su-Kil Park

Keyword(s):

Signal Transduction ◽

Endothelial Cells ◽

High Mobility ◽

Neutralizing Antibody ◽

High Mobility Group ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Aortic Endothelial Cells ◽

Tnf Α ◽

Human Aortic Endothelial Cells

Background/Aims: Toll-like receptor 4 (TLR4) interacts with endogenous substances as well as lipopolysaccharide. We explored whether TLR4 is implicated in tumor necrosis factor-α (TNF-α) signal transduction in human aortic endothelial cells. Methods: The pathway was evaluated by transfection of siRNAs, immunoprecipitation and Western blot analysis. Results: TNF-α activated spleen tyrosine kinase (Syk) within 10 min, which led to endothelin-1 (ET-1) production. TLR4 was also rapidly activated by TNF-α stimulation, as shown by recruitment of interleukin-1 receptor-associated kinase 1 to TLR4 and its adaptor molecule, myeloid differentiation factor 88 (MyD88). siRNA depletion of TLR4 markedly attenuated TNF-α-induced Syk activation and ET-1 production. TLR4 inhibitor (CLI-095), TLR4-neutralizing antibody and siRNA depletion of MyD88 also attenuated TNF-α-induced Syk activation. Syk was co-immunoprecipitated with TLR4, and TNF-α activated Syk bound to TLR4. High-mobility group box 1 (HMGB1) was rapidly released and associated with TLR4 after TNF-α stimulation with a peak at 5 min, which was prevented by N-acetylcysteine, an antioxidant. Glycyrrhizin (HMGB1 inhibitor), HMGB1-neutralizing antibody and siRNA depletion of HMGB1 all suppressed TNF-α-induced Syk activation and ET-1 production. Conclusion: Upon TNF-α stimulation, TLR4 is activated by HMGB1 that is immediately released after the generation of reactive oxygen species, and plays a crucial role in the signal transduction.

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Toll-like receptor 4 (TLR4) on hepatocytes mediates high mobility group box-1 (HMGB1) release after hepatic ischemia reperfusion in a JNK-dependent manner

Journal of the American College of Surgeons ◽

10.1016/j.jamcollsurg.2012.06.358 ◽

2012 ◽

Vol 215 (3) ◽

pp. S139

Author(s):

Gary W. Nace ◽

Hai Huang ◽

John R. Klune ◽

Raymond E. Eid ◽

Timothy R. Billiar ◽

...

Keyword(s):

Ischemia Reperfusion ◽

High Mobility ◽

High Mobility Group ◽

Dependent Manner ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Hepatic Ischemia ◽

Hepatic Ischemia Reperfusion

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Circulating high mobility group box-1 and toll-like receptor 4 expressions increase the risk and severity of epilepsy

Brazilian Journal of Medical and Biological Research ◽

10.1590/1414-431x20197374 ◽

2019 ◽

Vol 52 (7) ◽

Cited By ~ 3

Author(s):

Minchen Kan ◽

Lihong Song ◽

Xueqiang Zhang ◽

Jing Zhang ◽

Pingping Fang

Keyword(s):

High Mobility ◽

High Mobility Group ◽

Toll Like Receptor ◽

Toll Like Receptor 4

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Betaine Protects Against High-Fat-Diet-Induced Liver Injury by Inhibition of High-Mobility Group Box 1 and Toll-Like Receptor 4 Expression in Rats

Digestive Diseases and Sciences ◽

10.1007/s10620-013-2775-x ◽

2013 ◽

Vol 58 (11) ◽

pp. 3198-3206 ◽

Cited By ~ 44

Author(s):

Wei Zhang ◽

Lu-wen Wang ◽

Li-kun Wang ◽

Xun Li ◽

Hong Zhang ◽

...

Keyword(s):

Liver Injury ◽

High Fat Diet ◽

High Mobility ◽

High Mobility Group ◽

Toll Like Receptor ◽

High Fat ◽

Toll Like Receptor 4

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Micrococcus luteus Teichuronic Acids Activate Human and Murine Monocytic Cells in a CD14- and Toll-Like Receptor 4-Dependent Manner

Infection and Immunity ◽

10.1128/iai.69.4.2025-2030.2001 ◽

2001 ◽

Vol 69 (4) ◽

pp. 2025-2030 ◽

Cited By ~ 32

Author(s):

Shuhua Yang ◽

Shunji Sugawara ◽

Toshihiko Monodane ◽

Masahiro Nishijima ◽

Yoshiyuki Adachi ◽

...

Keyword(s):

Lipid A ◽

Micrococcus Luteus ◽

Dependent Manner ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Necrosis Factor Alpha ◽

Monocytic Cells ◽

Tnf Α

ABSTRACT Teichuronic acid (TUA), a component of the cell walls of the gram-positive organism Micrococcus luteus (formerlyMicrococcus lysodeikticus), induced inflammatory cytokines in C3H/HeN mice but not in lipopolysaccharide (LPS)-resistant C3H/HeJ mice that have a defect in the Toll-like receptor 4 (TLR4) gene, both in vivo and in vitro, similarly to LPS (T. Monodane, Y. Kawabata, S. Yang, S. Hase, and H. Takada, J. Med. Microbiol. 50:4–12, 2001). In this study, we found that purified TUA (p-TUA) induced tumor necrosis factor alpha (TNF-α) in murine monocytic J774.1 cells but not in mutant LR-9 cells expressing membrane CD14 at a lower level than the parent J774.1 cells. The TNF-α-inducing activity of p-TUA in J774.1 cells was completely inhibited by anti-mouse CD14 monoclonal antibody (MAb). p-TUA also induced interleukin-8 (IL-8) in human monocytic THP-1 cells differentiated to macrophage-like cells expressing CD14. Anti-human CD14 MAb, anti-human TLR4 MAb, and synthetic lipid A precursor IVA, an LPS antagonist, almost completely inhibited the IL-8-inducing ability of p-TUA, as well as LPS, in the differentiated THP-1 cells. Reduced p-TUA did not exhibit any activities in J774.1 or THP-1 cells. These findings strongly suggested that M. luteus TUA activates murine and human monocytic cells in a CD14- and TLR4-dependent manner, similar to LPS.

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