The effect of fenofibrate, a PPARα activator on toll-like receptor-4 signal transduction in melanoma both in vitro and in vivo

Traumatic brain injury (TBI) is one of the leading causes of mortality and disability worldwide without any validated biomarker or set of biomarkers to help the diagnosis and evaluation of the evolution/prognosis of TBI patients. To achieve this aim, a deeper knowledge of the biochemical and pathophysiological processes triggered after the trauma is essential. Here, we identified the serum amyloid A1 protein-Toll-like receptor 4 (SAA1-TLR4) axis as an important link between inflammation and the outcome of TBI patients. Using serum and mRNA from white blood cells (WBC) of TBI patients, we found a positive correlation between serum SAA1 levels and injury severity, as well as with the 6-month outcome of TBI patients. SAA1 levels also correlate with the presence of TLR4 mRNA in WBC. In vitro, we found that SAA1 contributes to inflammation via TLR4 activation that releases inflammatory cytokines, which in turn increases SAA1 levels, establishing a positive proinflammatory loop. In vivo, post-TBI treatment with the TLR4-antagonist TAK242 reduces SAA1 levels, improves neurobehavioral outcome, and prevents blood–brain barrier disruption. Our data support further evaluation of (i) post-TBI treatment in the presence of TLR4 inhibition for limiting TBI-induced damage and (ii) SAA1-TLR4 as a biomarker of injury progression in TBI patients.

Download Full-text

Ginsenoside Rb1 exerts anti-inflammatory effects in vitro and in vivo by modulating toll-like receptor 4 dimerization and NF-kB/MAPKs signaling pathways

Phytomedicine ◽

10.1016/j.phymed.2020.153197 ◽

2020 ◽

Vol 69 ◽

pp. 153197 ◽

Cited By ~ 5

Author(s):

Hongwei Gao ◽

Naixin Kang ◽

Chao Hu ◽

Ziyu Zhang ◽

Qiongming Xu ◽

...

Keyword(s):

Signaling Pathways ◽

Ginsenoside Rb1 ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Anti Inflammatory

Download Full-text

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.

Download Full-text

Pseudomonas aeruginosa Lipopolysaccharide Induces Osteoclastogenesis Through a Toll-Like Receptor 4 Mediated Pathway in Vitro and in Vivo

The Laryngoscope ◽

10.1097/mlg.0b013e318033783a ◽

2007 ◽

Vol 117 (5) ◽

pp. 841-847 ◽

Cited By ~ 23

Author(s):

Lei Zhuang ◽

Jae Y. Jung ◽

Eric W. Wang ◽

Patrick Houlihan ◽

Lisette Ramos ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Toll Like Receptor ◽

Toll Like Receptor 4

Download Full-text

Leukocyte- and Platelet-Derived Microvesicle Interactions following In Vitro and In Vivo Activation of Toll-Like Receptor 4 by Lipopolysaccharide

PLoS ONE ◽

10.1371/journal.pone.0025504 ◽

2011 ◽

Vol 6 (9) ◽

pp. e25504 ◽

Cited By ~ 5

Author(s):

Jing Xiong ◽

Virginia M. Miller ◽

Larry W. Hunter ◽

Yunman Li ◽

Muthuvel Jayachandran

Keyword(s):

Toll Like Receptor ◽

Toll Like Receptor 4

Download Full-text

194 A Non-Gluten Component of Wheat is a Strong Stimulator of Innate Immune Responses In Vitro and In Vivo and Acts via Toll Like Receptor 4

Gastroenterology ◽

10.1016/s0016-5085(10)60165-5 ◽

2010 ◽

Vol 138 (5) ◽

pp. S-36

Author(s):

Yvonne Junker ◽

Donatella Barisani ◽

Daniel A. Leffler ◽

Towia Libermann ◽

Simon T. Dillon ◽

...

Keyword(s):

Immune Responses ◽

Innate Immune ◽

Innate Immune Responses ◽

Toll Like Receptor ◽

Toll Like Receptor 4

Download Full-text

Vitamin D inhibits lipopolysaccharide-induced inflammatory response potentially through the Toll-like receptor 4 signalling pathway in the intestine and enterocytes of juvenile Jian carp (Cyprinus carpio var. Jian)

British Journal Of Nutrition ◽

10.1017/s0007114515003256 ◽

2015 ◽

Vol 114 (10) ◽

pp. 1560-1568 ◽

Cited By ~ 21

Author(s):

Jun Jiang ◽

Dan Shi ◽

Xiao-Qiu Zhou ◽

Long Yin ◽

Lin Feng ◽

...

Keyword(s):

Vitamin D ◽

Inflammatory Response ◽

Mrna Expression ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Jian Carp ◽

Pre Treatment ◽

Inflammatory Effect

AbstractThe present study was conducted to investigate the anti-inflammatory effect of vitamin D both in juvenile Jian carp (Cyprinus carpio var. Jian) in vivo and in enterocytes in vitro. In primary enterocytes, exposure to 10 mg lipopolysaccharide (LPS)/l increased lactate dehydrogenase activity in the culture medium (P<0·05) and resulted in a significant loss of cell viability (P<0·05). LPS exposure increased (P<0·05) the mRNA expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-8), which was decreased by pre-treatment with 1,25-dihydroxyvitamin D (1,25D3) in a dose-dependent manner (P<0·05). Further results showed that pre-treatment with 1,25D3 down-regulated Toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (Myd88) and NF-κB p65 mRNA expression (P<0·05), suggesting potential mechanisms against LPS-induced inflammatory response. In vivo, intraperitoneal injection of LPS significantly increased TNF-α, IL-1β, IL-6 and IL-8 mRNA expression in the intestine of carp (P<0·05). Pre-treatment of fish with vitamin D3 protected the fish intestine from the LPS-induced increase of TNF-α, IL-1β, IL-6 and IL-8 mainly by downregulating TLR4, Myd88 and NF-κB p65 mRNA expression (P<0·05). These observations suggest that vitamin D could inhibit LPS-induced inflammatory response in juvenile Jian carp in vivo and in enterocytes in vitro. The anti-inflammatory effect of vitamin D is mediated at least in part by TLR4-Myd88 signalling pathways in the intestine and enterocytes of juvenile Jian carp.

Download Full-text

Toll-like receptor 4 is activated by platinum and contributes to cisplatin-induced ototoxicity

10.1101/2020.06.19.162057 ◽

2020 ◽

Author(s):

Ghazal Babolmorad ◽

Asna Latif ◽

Niall M. Pollock ◽

Ivan K. Domingo ◽

Cole Delyea ◽

...

Keyword(s):

Transition Metals ◽

Hair Cell ◽

Childhood Cancer ◽

Small Molecule ◽

Therapeutic Target ◽

Outer Hair Cell ◽

Toll Like Receptor ◽

Toll Like Receptor 4

AbstractToll-like receptor 4 (TLR4) is famous for recognizing the bacterial endotoxin lipopolysaccharide (LPS) as its canonical ligand. TLR4 is also activated by other classes of agonist including some Group 9/10 transition metals. Roles for these non-canonical ligands in pathobiology mostly remain obscure, though TLR4 interactions with metals can mediate immune hypersensitivity reactions. In this work, we tested whether TLR4 can be activated by the Group 10 transition metal, platinum. We demonstrated that in the presence of TLR4, platinum activates pathways downstream of TLR4 to a similar extent as the known TLR4 agonists LPS and nickel. Platinum is the active moiety in cisplatin, a very potent and invaluable chemotherapeutic used to treat solid tumors in childhood cancer patients. Unfortunately, cisplatin use is limited due to an adverse effect of permanent hearing loss (cisplatin-induced ototoxicity, CIO). Herein, we demonstrated that cisplatin also activates TLR4, prompting the hypothesis that TLR4 mediates aspects of CIO. Cisplatin activation of TLR4 was independent of the TLR4 co-receptors CD14 and MD-2, which is consistent with TLR4 signaling elicited by transition metals. We found that TLR4 is required for cisplatin-induced inflammatory, oxidative and apoptotic responses in an ear outer hair cell line and for hair cell damage in vivo. Thus, TLR4 is a promising therapeutic target to mitigate CIO. We additionally identify a TLR4 small molecule inhibitor able to curtail cisplatin toxicity in vitro. Further work is warranted towards inhibiting TLR4 as a route to mitigating this adverse outcome of childhood cancer treatment.Significance StatementThis work identifies platinum, and its derivative cisplatin, as new agonists for TLR4. TLR4 contributes to cisplatin-induced hair cell death in vitro and in vivo. Genetic and small molecule inhibition of TLR4 identify this receptor as a druggable therapeutic target with promise to curtail cisplatin-induced ototoxicity, a devastating side-effect of an otherwise invaluable chemotherapeutic tool.

Download Full-text