eritoran and Disease-Models--Animal

Toll-like receptor 4 (TLR4) recognizes lipopolysaccharides and endogenous ligands released after organ injury. Deficiency of TLR4 attenuates the development of left ventricular hypertrophy after transverse aortic constriction (TAC) in mice. We hypothesized that application of the TLR4 antagonist eritoran may also reduce cardiac hypertrophy after TAC surgery.. A catheter was implanted into the jugular vein of C57BL/6 mice to allow repeated administration of eritoran (5 mg/kg body weight) or placebo. Three days after TAC or sham surgery, heart weights were determined and cardiac tissue underwent mRNA and protein quantification. The TAC placebo group exhibited a significant increase in left ventricular weight, left ventricular weight/tibia length, and left ventricular/body weight ratio compared with the sham and TAC eritoran groups. Natriuretic peptide mRNA was elevated significantly only in TAC placebo mice. Transverse aortic constriction surgery led to a distinct increase in interleukin (IL)-1β and IL-6 mRNA and protein expression in the placebo but not the eritoran group. In contrast, IL-10 was significantly increased in both eritoran groups independent from TAC. Matrix metalloproteinase zymographic activity was highest in TAC placebo animals.. Application of the TLR4 antagonist eritoran attenuates the development of cardiac hypertrophy possibly by a reduction in inflammatory and increase in anti-inflammatory cytokines.

Topics: Animals; Cardiomegaly; Disaccharides; Disease Models, Animal; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Interleukins; Male; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Natriuretic Peptide, Brain; Reverse Transcriptase Polymerase Chain Reaction; Sugar Phosphates; Toll-Like Receptor 4

The coronavirus disease 2019 (COVID-19) pandemic threatens human species with mortality rate of roughly 2%. We can hardly predict the time of herd immunity against and end of COVID-19 with or without success of vaccine. One way to overcome the situation is to define what delineates disease severity and serves as a molecular target. The most successful analogy is found in BCR-ABL in chronic myeloid leukemia, which is the golden biomarker, and simultaneously, the most effective molecular target. We hypothesize that S100 calcium-binding protein A8 (S100A8) is one such molecule. The underlying evidence includes accumulating clinical information that S100A8 is upregulated in severe forms of COVID-19, pathological similarities of the affected lungs between COVID-19 and S100A8-induced acute respiratory distress syndrome (ARDS) model, homeostatic inflammation theory in which S100A8 is an endogenous ligand for endotoxin sensor Toll-like receptor 4/Myeloid differentiation protein-2 (TLR4/MD-2) and mediates hyper-inflammation even after elimination of endotoxin-producing extrinsic pathogens, analogous findings between COVID-19-associated ARDS and pre-metastatic lungs such as S100A8 upregulation, pulmonary recruitment of myeloid cells, increased vascular permeability, and activation coagulation cascade. A successful treatment in an animal COVID-19 model is given with a reagent capable of abrogating interaction between S100A8/S100A9 and TLR4. In this paper, we try to verify our hypothesis that S100A8 governs COVID-19-associated ARDS.

Topics: Angiotensin-Converting Enzyme 2; Animals; Antiviral Agents; Calgranulin A; Chemokine CXCL11; COVID-19; Cytokine Release Syndrome; Disaccharides; Disease Models, Animal; Drug Discovery; Epithelial Cells; Humans; Inflammation; Lung; Lung Neoplasms; Lymphocyte Antigen 96; Macaca mulatta; Mice; Mice, Transgenic; Models, Biological; Mutation; Pandemics; Respiratory Distress Syndrome; SARS-CoV-2; Species Specificity; Sugar Phosphates; Toll-Like Receptor 4; Up-Regulation; Virus Internalization

Host-derived "danger-associated molecular patterns" (DAMPs) contribute to innate immune responses and serve as markers of disease progression and severity for inflammatory and infectious diseases. There is accumulating evidence that generation of DAMPs such as oxidized phospholipids and high-mobility-group box 1 (HMGB1) during influenza virus infection leads to acute lung injury (ALI). Treatment of influenza virus-infected mice and cotton rats with the Toll-like receptor 4 (TLR4) antagonist Eritoran blocked DAMP accumulation and ameliorated influenza virus-induced ALI. However, changes in systemic HMGB1 kinetics during the course of influenza virus infection in animal models and humans have yet to establish an association of HMGB1 release with influenza virus infection. To this end, we used the cotton rat model that is permissive to nonadapted strains of influenza A and B viruses, respiratory syncytial virus (RSV), and human rhinoviruses (HRVs). Serum HMGB1 levels were measured by an enzyme-linked immunosorbent assay (ELISA) prior to infection until day 14 or 18 post-infection. Infection with either influenza A or B virus resulted in a robust increase in serum HMGB1 levels that decreased by days 14 to 18. Inoculation with the live attenuated vaccine FluMist resulted in HMGB1 levels that were significantly lower than those with infection with live influenza viruses. RSV and HRVs showed profiles of serum HMGB1 induction that were consistent with their replication and degree of lung pathology in cotton rats. We further showed that therapeutic treatment with Eritoran of cotton rats infected with influenza B virus significantly blunted serum HMGB1 levels and improved lung pathology, without inhibiting virus replication. These findings support the use of drugs that block HMGB1 to combat influenza virus-induced ALI.

Topics: Animals; Biomarkers; Disaccharides; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; HMGB1 Protein; Immunologic Factors; Orthomyxoviridae Infections; Picornaviridae Infections; Respiratory Syncytial Virus Infections; Serum; Sigmodontinae; Sugar Phosphates; Treatment Outcome

Depression is the disease of the modern era. The lack of response to the available antidepressants, which were developed on the basis of the monoaminergic deficit hypothesis of depression, has encouraged scientists to think about new mechanisms explaining the pathogenesis of depression. In this context, the inflammatory theory has emerged to clarify many aspects of depression that the previous theories have failed to explain. Toll-like receptor-4 (TLR-4) has a regulatory role in the brain's immune response to stress, and its activation is suggested to play a pivotal role in the pathophysiology of depression. In this study, we tested eritoran (ERI), a TLR-4 receptor-4 antagonist, as a potential antidepressant. We investigated the effect of long-term administration of ERI in three different doses on behavioral changes, hippocampal and prefrontal cortex (PFC) neurogenesis, and γ-aminobutyric acid (GABA)/glutamate balance in male Wistar rats exposed to chronic restraint stress (CRS). Long-term administration of ERI ameliorated CRS-induced depressive-like symptoms and hypothalamic-pituitary-adrenal axis hyperactivity alongside reducing levels of hippocampal and PFC inflammatory cytokines, restoring GABA and glutamate balance, and enhancing PFC and hippocampal neurogenesis, by increasing BDNF gene and protein expression in a dose-dependent manner. The results demonstrate an antidepressant-like activity of ERI in Wistar rats exposed to CRS, which may be largely mediated by its ability to reduce neuroinflammation, increase BDNF, and restore GABA/glutamate balance in prefrontal cortex and hippocampus. Nonetheless, further studies are needed to characterize the mechanism of the antidepressant effect of ERI.

Topics: Animals; Antidepressive Agents; Brain-Derived Neurotrophic Factor; Depression; Depressive Disorder; Disaccharides; Disease Models, Animal; gamma-Aminobutyric Acid; Glutamic Acid; Hippocampus; Hypothalamo-Hypophyseal System; Male; Neurogenesis; Pituitary-Adrenal System; Prefrontal Cortex; Rats; Rats, Wistar; Stress, Psychological; Sugar Phosphates; Toll-Like Receptor 4

The 2013-2016 outbreak of Ebola virus (EBOV) in West Africa, which has seen intermittent reemergence since it was officially declared over in February of 2016, has demonstrated the need for the rapid development of therapeutic intervention strategies. Indirect evidence has suggested that the EBOV infection shares several commonalities associated with the onset of bacterial sepsis, including the development of a "cytokine storm." Eritoran, a Toll-like receptor 4 (TLR4) antagonist, was previously shown to result in protection of mice against lethal influenza virus infection. Here, we report that eritoran protects against the lethality caused by EBOV and the closely related Marburg virus (MARV) in mice. Daily administration of eritoran reduced clinical signs of the disease and, unexpectedly, resulted in reduced viral titers. Analysis of peripheral blood indicated that eritoran reduced granulocytosis despite an apparent increase in the percentage of activated neutrophils. Surprisingly, the increased survival rate and reduced viremia were not accompanied by increased CD3

Topics: Animals; Cytokines; Disaccharides; Disease Models, Animal; Hemorrhagic Fever, Ebola; Immunologic Factors; Marburg Virus Disease; Mice; Sugar Phosphates; Survival Analysis; Toll-Like Receptor 4; Treatment Outcome

Colorectal carcinogenesis is affected by overexpression of the lipopolysaccharide (LPS) receptors CD14 and TLR4, which antagonize each other by affecting epithelial cell proliferation and apoptosis. Eritoran is an investigational drug for sepsis treatment that resembles the lipid A moiety of LPS and therefore acts as a TLR4 inhibitor. In the present study, we explored the potential therapeutic uses and mechanisms of action of eritoran in reducing colon cancer progression. Eritoran administration via intracolonic, intragastric, or intravenous routes significantly reduced tumor burden in a chemically induced mouse model of colorectal carcinoma. Decreased proliferation and increased apoptosis were observed in mouse tumor cells after eritoran treatment. In vitro cultures of mouse primary tumor spheroids and human cancer cell lines displayed increased cell proliferation and cell-cycle progression following LPS challenge. This effect was inhibited by eritoran and by silencing CD14 or TLR4. In contrast, apoptosis induced by eritoran was eliminated by silencing CD14 or protein kinase Cζ (PKCζ) but not TLR4. Lastly, LPS and eritoran caused hyperphosphorylation of PKCζ in a CD14-dependent and TLR4-independent manner. Blocking PKCζ activation by a Src kinase inhibitor and a PKCζ-pseudosubstrate prevented eritoran-induced apoptosis. In summary, our work offers a preclinical proof of concept for the exploration of eritoran as a clinical treatment, with a mechanistic rationale to reposition this drug to improve the management of colorectal cancer. Cancer Res; 76(16); 4684-95. ©2016 AACR.

Topics: Animals; Antineoplastic Agents; Apoptosis; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Disaccharides; Disease Models, Animal; Fluorescent Antibody Technique; Humans; In Situ Nick-End Labeling; Lipopolysaccharide Receptors; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Sugar Phosphates; Toll-Like Receptor 4

Pain caused by acute pulpitis (AP) is a common symptom in clinical settings. However, its underlying mechanisms have largely remained unknown. Using AP model, we demonstrated that dental injury caused severe pulp inflammation with up-regulated serum IL-1β. Assessment from head-withdrawal reflex thresholds (HWTs) and open-field test demonstrated nociceptive response at 1 day post injury. A consistent up-regulation of Toll-like receptor 4 (TLR4) in the trigeminal ganglion (TG) ipsilateral to the injured pulp was found; and downstream signaling components of TLR4, including MyD88, TRIF and NF-κB, and cytokines such as TNF-α and IL-1β, were also increased. Retrograde labeling indicated that most TLR4 positve neuron in the TG innnervated the pulp and TLR4 immunoreactivity was mainly in the medium and small neurons. Double labeling showed that the TLR4 expressing neurons in the ipsilateral TG were TRPV1 and CGRP positive, but IB4 negative. Furthermore, blocking TLR4 by eritoran (TLR4 antagonist) in TGs of the AP model significantly down-regulated MyD88, TRIF, NF-κB, TNF-α and IL-1β production and behavior of nociceptive response. Our findings suggest that TLR4 signaling in TG cells, particularly the peptidergic TRPV1 neurons, plays a key role in AP-induced nociception, and indicate that TLR4 signaling could be a potential therapeutic target for orofacial pain.

Topics: Animals; Dental Pulp; Disaccharides; Disease Models, Animal; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Immunohistochemistry; Interleukin-1beta; Male; Microscopy, Fluorescence; Myeloid Differentiation Factor 88; Neurons; NF-kappa B; Nociception; Pulpitis; Rats; Rats, Sprague-Dawley; Signal Transduction; Sugar Phosphates; Toll-Like Receptor 4; Trigeminal Ganglion; Tumor Necrosis Factor-alpha; Up-Regulation

Purpose. To investigate the corneal expression of toll-like receptor (TLR) 4 and determine its contribution to the immunopathogenesis of dry eye disease (DED). Methods. Seven to 8-week-old female C57BL/6 mice were housed in a controlled environment chamber and administered scopolamine to induce experimental DED. Mice received intravenous TLR4 inhibitor (Eritoran) to block systemic TLR4-mediated activity. The expression of TLR4 by the corneal epithelium and stroma was evaluated using real-time polymerase chain reaction and flow cytometry. Corneal fluorescein staining (CFS) was performed to evaluate clinical disease severity. The corneal expression of proinflammatory cytokines (IL-1β, IL-6, TNF, and CCL2), corneal infiltration of CD11b(+) antigen-presenting cells, and lymph node frequency of mature MHC-II(hi) CD11b(+) cells were assessed. Results. The epithelial cells of normal corneas expressed TLR4 intracellularly; however, DED significantly increased the cell surface expression of TLR4. Similarly, flow cytometric analysis of stromal cells revealed a significant increase in the expression of TLR4 proteins by DED-induced corneas as compared with normal corneas. DED increased the mRNA expression of TLR4 in corneal stromal cells, but not epithelial cells. TLR4 inhibition decreased the severity of CFS and significantly reduced the mRNA expression of IL-1β, IL-6, and TNF. Furthermore, TLR4 inhibition significantly reduced the corneal infiltration of CD11b(+) cells and the lymph node frequency of MHC-II(hi) CD11b(+) cells. Conclusions. These results suggest that DED increases the corneal expression of TLR4 and that TLR4 participates in the inflammatory response to ocular surface desiccating stress.

Topics: Animals; Cholinergic Antagonists; Corneal Stroma; Cytoplasm; Dendritic Cells; Disaccharides; Disease Models, Animal; Dry Eye Syndromes; Epithelium, Corneal; Female; Gene Expression; Interleukin-1beta; Interleukin-6; Keratitis; Mice; Mice, Inbred C57BL; Receptors, Cell Surface; RNA, Messenger; Scopolamine; Sugar Phosphates; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

Peroxisome proliferator-activated receptor γ (PPARγ) has been reported to attenuate intimal hyperplasia. This study aimed to test the hypothesis that PPARγ inhibits intimal hyperplasia through suppressing Toll-like receptor 4 (TLR4)-mediated inflammation in vascular smooth muscle cells.. TLR4(-/-) mice on a C57BL/6J background were used. Increased TLR4 and pro-inflammatory cytokines were observed in wire-injury-induced carotid neointima and in platelet-derived growth factor (PDGF)-activated vascular smooth muscle cells. The TLR4 deficiency protected the injured carotid from neointimal formation and impaired the cellular proliferation and migration in response to lipopolysaccharide and PDGF. Rosiglitazone attenuated intimal hyperplasia. Overexpression of PPARγ suppressed PDGF-induced proliferation and migration and inhibited TLR4-mediated inflammation in vascular smooth muscle cells, while PPARγ silencing exerted the opposite effect. Lipopolysaccharide counteracted the inhibitory effect of PPARγ on PDGF-induced proliferation and migration. Eritoran suppressed the proliferation and migration induced by PDGF and PPARγ silencing. Vascular smooth muscle cells derived from TLR4(-/-) mice showed impaired proliferation and migration upon PDGF activation and displayed no response to PPARγ manipulation.. PPARγ inhibits vascular smooth muscle cell proliferation and migration by suppressing TLR4-mediated inflammation and ultimately attenuates intimal hyperplasia after carotid injury.

Topics: Animals; Carotid Artery Injuries; Cell Movement; Cell Proliferation; Cells, Cultured; Disaccharides; Disease Models, Animal; Hyperplasia; Inflammation; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Platelet-Derived Growth Factor; PPAR gamma; RNA Interference; Rosiglitazone; Sugar Phosphates; Thiazolidinediones; Toll-Like Receptor 4; Transfection; Tunica Intima

Ischemia-reperfusion injury (I/R) has a negative effect on renal allograft survival. Using a rat model of kidney IR injury, we demonstrated inhibition of Toll-like receptor (TLR) 4 with erotoran may shed new light on I/R therapy.. All 44 Fisher rats were anesthetized with ethrane. Animals were randomly divided into the S group (sham, n = 11) that received only right kidney nephrectomy or the I/R group of right kidney nephrectomy and ichemia for 40 minutes by clamping of left renal artery (n = 11). In addition, the E group (Eritoran, n = 11) and the V group (vehicle, n = 11) received eritoran (5 mg x kg(-1)) and vehicle pretreatment, respectively. Analysis of renal histology, function, cytokine/chemokine production, as well as animal mortality was performed in parallel groups by ribonuclease protection assay (RPA).. At 24 hours, the creatinine value 1.49 +/- 0.2 mg/dL in the eritoran group was significantly lower than untreated controls (2.17 +/- 0.4 mg/dL). Histological findings showed tubular loss and morphological stutus as well as animal survival post-I/R injury compared to vehicle-treated rats; the difference between the S versus E groups was significant. Eritoran administration significantly attenuated monocyte infiltration into the kidney. RPA assays showed the following fold increase over sham normalized to that of GAPDH mRNA expression of tumor necrosis factor-alpha (4.67 +/- 1.52 vs 1.37 +/- 0.05), interleukin (IL)-1beta (5.11 +/- 1.17 vs 1.92 +/- 0.27), IL-6 (4.20 +/- 0.29 vs 1.21 +/- 0.37) and monocyte chemoattractant protein-1 (8.77 +/- 1.24 vs 2.57 +/- 1.59). GAPDH was markedly reduced by eritoran treatment (eritoran vs vehicle group).. These data demonstrated that inhibition of TLR4 with eritoran reduced I/R-related inflammatory responses and improved the course of kidney I/R injury.

Topics: Animals; Chemokines; Creatinine; Cytokines; Disaccharides; Disease Models, Animal; Kidney; Kidney Function Tests; Male; Rats; Rats, Inbred F344; Renal Artery; Renal Circulation; Reperfusion Injury; RNA, Messenger; Sugar Phosphates; Toll-Like Receptor 4

Aim was to assess whether lipopolysaccharide (LPS)-induced decrease of total peripheral resistance depends on Toll-like receptor (TLR)4 signaling and whether it is sensitive to NO-synthase or TLR4 antagonists.. C3H/HeN mice (control), expressing a functional, and C3H/HeJ mice, expressing a nonfunctional TLR4, were compared. LPS (20 mg/kg) was injected i.p. 6 hours before hemodynamic measurements. L-NAME and SMT, inhibitors of NO production, and Eritoran, a TLR4 antagonist, were tested for their impact on vascular contractility. Aortic rings were incubated for 6 hours with or without LPS (1 microg/mL), or with LPS+Eritoran (2 microg/mL) and their phenylephrine-induced contractility was measured using a myograph. The expression of cytokines in aortic tissue was examined by real-time polymerase chain reaction. In control mice LPS induced a significant decrease of blood pressure and an increase of heart rate, whereas C3H/HeJ remained unaffected. LPS induced an increase of cytokine expression and a depression of vascular contractility only in control mice but not in C3H/HeJ. L-NAME and SMT increased contractility in all rings and restored LPS-dependent depression of contractility. Eritoran prevented LPS-induced loss of contractility.. LPS upregulates cytokine expression via TLR4 and induces attenuation of smooth muscle contractility which can be effectively antagonized.

Topics: Animals; Aorta; Blood Pressure; Cytokines; Disaccharides; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Inhibitors; Heart Rate; Isothiuronium; Lipopolysaccharides; Mice; Mice, Inbred C3H; Mice, Mutant Strains; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase Type II; Point Mutation; RNA, Messenger; Shock, Septic; Signal Transduction; Sugar Phosphates; Time Factors; Toll-Like Receptor 4; Vasoconstriction