OBJECTIVE: To explore the mechanism of effects of total saponin fraction from Dioscorea Nipponica Makino (TSDN) on M1/M2 polarization of monocytes/macrophages and arachidonic acid (AA) pathway in rats with gouty arthritis (GA). METHODS: Seventy-two Sprague Dawley rats were randomly divided into 4 groups (n=18 in each): normal, model, TSDN at 160 mg/kg, and celecoxib at 43.3 mg/kg. Monosodium urate crystal (MSU) was injected into the rats' ankle joints to induce an experimental GA model. Blood and tissue samples were collected on the 3rd, 5th, and 8th days of drug administration. Histopathological changes in the synovium of joints were observed via hematoxylin and eosin (HE) staining. The expression levels of arachidonic acid (AA) signaling pathway were assessed via real-time polymerase chain reaction (qPCR) and Western blot. Flow cytometry was used to determine the proportion of M1 and M2 macrophages in the peripheral blood. An enzyme-linked immunosorbent assay (ELISA) was used to detect interleukine (IL)-1 β, tumor necrosis factor-alpha (TNF-α), IL-4, IL-10, prostaglandin E₂ (PGE₂), and leukotriene B4 (LTB4). RESULTS: HE staining showed that TSDN improved the synovial tissue. qPCR and Western blot showed that on the 3rd, 5th and 8th days of drug administration, TSDN reduced the mRNA and protein expressions of cyclooxygenase (COX)2, microsomal prostaglandin E synthase-1 derived eicosanoids (mPGES-1), 5-lipoxygenase (5-LOX), recombinant human mothers against decapentaplegic homolog 3 (Smad3), nucleotide-binding oligomerization domain-like receptor protein 3 (NALP3), and inducible nitric oxide synthase (iNOS) in rats' ankle synovial tissues (P<0.01). TSDN decreased COX1 mRNA and protein expression on 3rd and 5th day of drug administration and raised it on the 8th day (both P<0.01). It lowered CD68 protein expression on days 3 (P<0.01), as well as mRNA and protein expression on days 5 and 8 (P<0.01). On the 3rd, 5th, and 8th days of drug administration, TSDN elevated the mRNA and protein expression of Arg1 and CD163 (P<0.01). Flow cytometry results showed that TSDN decreased the percentage of M1 macrophages while increasing the percentage of M2 in peripheral blood (P<0.05 or P<0.01). ELISA results showed that on the 3rd, 5th, and 8th days of drug administration, TSDN decreased serum levels of IL-1 β, TNF-α, and LTB4 (P<0.01), as well as PGE₂ levels on days 3rd and 8th days (P<0.05 or P<0.01); on day 8 of administration, TSDN increased IL-4 serum levels and enhanced IL-10 contents on days 5 and 8 (P<0.05 or P<0.01). CONCLUSION The anti-inflammatory effect of TSDN on rats with GA may be achieved by influencing M1/M2 polarization through AA signaling pathway.
Rats ; Humans ; Animals ; Arthritis, Gouty/drug therapy* ; Monocytes/pathology* ; Interleukin-10/metabolism* ; Arachidonic Acid/pharmacology* ; Dioscorea/chemistry* ; Rats, Wistar ; Tumor Necrosis Factor-alpha/metabolism* ; Saponins/therapeutic use* ; Interleukin-4/metabolism* ; Leukotriene B4/pharmacology* ; Rats, Sprague-Dawley ; Macrophages ; Signal Transduction ; RNA, Messenger/metabolism*

OBJECTIVE: To explore the expression patterns, prognostic implications, and biological role of leukotriene B4 receptor (LTB4R) in patients with acute myeloid leukemia (AML). METHODS: We collected the data of mRNA expression levels and clinical information of patients with AML from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database for mRNA expression analyses, survival analyses, Cox regression analyses and correlation analyses using R studio to assess the expression patterns and prognostic value of LTB4R. The correlation of LTB4R expression levels with clinical characteristics of the patients were analyzed using UALCAN. The co-expressed genes LTB4R were screened from Linkedomics and subjected to functional enrichment analysis. A protein-protein interaction network was constructed using STRING. GSEA analyses of the differentially expressed genes (DEGs) were performed based on datasets from TCGA-LAML stratified by LTB4R expression level. We also collected peripheral blood mononuclear cells (PBMCs) from AML patients and healthy donors for examination of the mRNA expression levels of LTB4R and immune checkpoint genes using qRT-PCR. We also examined serum LTB4R protein levels in the patients using ELISA. RESULTS: The mRNA expression level of LTB4R was significantly increased in AML patients (4.898±1.220 vs 2.252±0.215, P < 0.001), and an elevated LTB4R expression level was correlated with a poor overall survival (OS) of the patients (P=0.004, HR=1.74). LTB4R was identified as an independent prognostic factor for OS (P=0.019, HR=1.66) and was associated with FAB subtypes, cytogenetic risk, karyotype abnormalities and NPM1 mutations. The co- expressed genes of LTB4R were enriched in the functional pathways closely associated with AML leukemogenesis, including neutrophil inflammation, lymphocyte activation, signal transduction, and metabolism. The DEGs were enriched in differentiation, activation of immune cells, and cytokine signaling. Examination of the clinical serum samples also demonstrated significantly increased expressions of LTB4R mRNA (P=0.044) and protein (P=0.008) in AML patients, and LTB4R mRNA expression was positively correlated with the expression of the immune checkpoint HAVCR2 (r= 0.466, P=0.040). CONCLUSION LTB4R can serve as a novel biomarker and independent prognostic indicator of AML and its expression patterns provide insights into the crosstalk of leukemogenesis signaling pathways involving tumor immunity and metabolism.
Humans ; Leukemia, Myeloid, Acute/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Prognosis ; RNA, Messenger/metabolism* ; Receptors, Leukotriene B4/genetics*

Sjogren-Larsson syndrome (SLS) is a rare autosomal recessive neurocutaneous disorder with worldwide incidence of 0.4 per 100,000 people. It is characterized by the triad of congenital ichthyosis, spastic diplegia or quadriplegia, and mental retardation. Herein we report a 2-year-old male child with SLS, asthma, and recurrent pneumonia. SLS was confirmed by a molecular genetics study that revealed a deletion mutation in the ALDH3A2 gene. An ALDH3A2 gene mutation results in dysfunction of the microsomal enzyme fatty aldehyde dehydrogenase and impaired metabolism and accumulation of leukotriene B4, which is a key molecule and a pro-inflammatory mediator in developing allergic diseases, especially asthma. An increased level of leukotriene B4 has been reported in SLS patients. As far as we are aware, this is the first report of SLS associated with asthma and recurrent pneumonia. In conclusion, pediatricians should be aware of and evaluate patients with SLS for possible associated asthma and allergic disorders.
Aldehyde Dehydrogenase ; Asthma* ; Cerebral Palsy ; Child ; Child, Preschool ; Humans ; Ichthyosis ; Incidence ; Intellectual Disability ; Leukotriene B4 ; Male ; Metabolism ; Molecular Biology ; Neurocutaneous Syndromes ; Pneumonia* ; Quadriplegia ; Sequence Deletion ; Sjogren-Larsson Syndrome*

Endotoxic responses to bacterial lipopolysaccharide (LPS) are triggered by Toll-like receptor 4 (TLR4) and involve the production of inflammatory mediators, including interleukin-6 (IL-6), by macrophages. The detailed mechanism of IL-6 production by macrophages in response to LPS has remained unclear, however. We now show that LPS induces IL-6 synthesis in mouse peritoneal macrophages via the leukotriene B4 receptor BLT2. Our results suggest that TLR4-MyD88 signaling functions upstream of BLT2 and that the generation of reactive oxygen species (ROS) by NADPH oxidase 1 (Nox1) and consequent activation of the transcription factor nuclear factor (NF)-kappaB function downstream of BLT2 in this response. These results suggest that a TLR4-MyD88-BLT2-Nox1-ROS-NF-kappaB pathway contributes to the synthesis of IL-6 in LPS-stimulated mouse macrophages.
Animals ; Cell Line ; Interleukin-6/*biosynthesis ; Leukotriene B4/metabolism ; Ligands ; Lipopolysaccharides/immunology ; Macrophages/immunology/*metabolism ; Macrophages, Peritoneal/immunology/metabolism ; Mice ; Myeloid Differentiation Factor 88/*metabolism ; NADH, NADPH Oxidoreductases/metabolism ; NF-kappa B/metabolism ; Reactive Oxygen Species/metabolism ; Receptors, Leukotriene B4/*metabolism ; Signal Transduction

OBJECTIVETo observe the effect of montelukast treatment on levels of serum leukotriene B4 and urinary leukotriene E4 in infants with bronchiolitis.

METHODSSeventy-five children who were diagnosed with bronchiolitis between June 2014 and December 2014 were randomly assigned into two groups, one with thirty-eight cases as the montelukast treatment group and another thirty-seven cases as the control group. All of the children were given routine medical treatment. The children in the montelukast treatment group were additionally given montelukast daily (4 mg once a day, for 7 days). The serum leukotriene B4 and urinary leukotriene E4 levels were measured using ELISA before and after treatment. The relationship between serum leukotriene B4 and urinary leukotriene E4 levels was analyzed by Peason correlation analysis.

RESULTSAfter 7 days of treatment, the serum leukotriene B4 and urinary leukotriene E4 levels in the montelukast treatment and control groups were significantly reduced compared with before treatment (P<0.05). The montelukast treatment group showed significantly lower serum leukotriene B4 and urinary leukotriene E4 levels than the control group (P<0.05). The remission time of cough, wheezing and lung wheezes and the length of hospital stay in the montelukast treatment group were significantly shortened compared with the control group (P<0.05). There was a positive correlation between serum leukotriene B4 and urinary leukotriene E4 levels (r=0.723, P<0.05).

CONCLUSIONSMontelukast has a reliable clinical curative efficacy for bronchiolitis in infants, possibly by decreasing serum leukotriene D4 and urinary leukotriene E4 levels.

Acetates ; therapeutic use ; Bronchiolitis ; drug therapy ; metabolism ; Humans ; Infant ; Leukotriene B4 ; blood ; Leukotriene E4 ; urine ; Quinolines ; therapeutic use

OBJECTIVETo study the antalgic and antiphlogistic functions and mechanism of ronggudingtong (RGDT) plaster (traditional Chinese medicine).

METHODSThe painful models were established with hot plate test or acetic acid writhing and the inflammatory models were established with daubing dimethylbenzene on auricle or injecting formaldehyde in toe or synovial envelope to study the antalgic and antiphlogistic functions of RGDT Plaster. The total protein and leukotriene B4(LTB4) in inflammatory exudate were detected to investigate the antalgic and antiphlogistic mechanism of RGDT plaster. The mice were randomly divided into different groups (n = 11), on the basis of drug using, the indexes of pain threshold, swelling degree were observed. Sixty-six mice were used to establish gasbag synovitis model and randomly divided into normal control group,model control group, positive control group (Voltaren gel 0.8 mg/d)and low/medium/high dosage RGDT plaster treating groups(30 mg/d, 60 mg/d, 120 mg/d).

RESULTS30 mg/d, 60 mg/d,120 mg/d RGDT plaster could upgrade the pain thresholds, remit auricular and foot swelling (P < 0.05, P < 0.01), and degrade total protein and LTB4 in inflammatory exudates (P < 0.05, P < 0.01).

CONCLUSIONRGDT plaster has some antalgic and antiphlogistic functions, and one of the mechanisms is depressing synthesis of LTB4.

Analgesics ; pharmacology ; Animals ; Anti-Inflammatory Agents ; pharmacology ; Leukotriene B4 ; metabolism ; Medicine, Chinese Traditional ; Mice ; Pain ; drug therapy

OBJECTIVETo observe the effects of docosahexaenoic acid (DHA) on the expressions of TNF-α, IL-6, and leukotriene B4 (LTB4) in serum and expression of NF-κB in pulmonary tissue of rats with severe scald injury.

METHODSOne hundred and sixty SD rats were divided into sham injury (A), sham injury+DHA (B), scald (C), and scald+DHA (D) groups according to the random number table, with 40 rats in each group. Rats in groups A and B were sham injured, while rats in groups C and D were inflicted with 30% TBSA full-thickness scald on the back. Rats in groups B and D were injected with 0.5 mg/mL DHA solution with the dosage of 1 mL/kg via tail vein 5 minutes post injury, while rats in groups A and C with normal saline solution 1 mL/kg. At post injury hour (PIH) 3, 6, 12, 24, and 48, pulmonary tissue and abdominal aorta blood were collected from 8 rats in each group. The serum levels of TNF-α, IL-6, and LTB4 were determined with ELISA, and the protein expression of NF-κB p65 in pulmonary tissue was determined with Western blotting. Data were processed with analysis of variance of factorial design and LSD-t test.

RESULTS(1) The serum levels of TNF-α and IL-6 of rats in group A were similar to those of group B at each time point (with tTNF-α values from 0.223 to 0.947, tIL-6 values from 0.767 to 2.084, P values above 0.05). Compared with those of group A, the serum levels of TNF-α and IL-6 of rats in groups C and D were significantly higher at each time point (with tTNF-α values from 11.800 to 40.357, tIL-6 values from 10.334 to 39.321, P values below 0.01). The serum levels of TNF-α and IL-6 of rats in group D were significantly lower than those of group C at each time point (with tTNF-α values from -17.643 to -8.331, tIL-6 values from -21.596 to -6.332, P values below 0.01). The serum levels of TNF-α and IL-6 in groups C and D both showed a trend of increase earlier and decrease later, and they peaked at PIH 12, respectively (360.4 ± 13.2), (306.8 ± 7.2) pg/mL and (265.4 ± 12.3), (230.5 ± 2.2) pg/mL. (2) The serum level of LTB4 in group A was similar to that of group B at each time point (with t values from 0.787 to 1.096, P values above 0.05). The serum level of LTB4 was significantly higher in groups C and D than in group A at each time point (with t values from 7.501 to 38.962, P values below 0.01). The serum level of LTB4 in group D was obviously lower than that of group C at each time point (with t values from -19.244 to -2.532, P values below 0.01). The serum level of LTB4 in groups C and D both showed a trend of increase earlier and decrease later, and it peaked at PIH 12, (4.59 ± 0.29) and (2.85 ± 0.32) ng/mL respectively. (3) The protein expression of NF-κB p65 in pulmonary tissue in group A was similar to that of group B at each time point (with t values from 0.847 to 1.256, P values above 0.05). The protein expression of NF-κB p65 was significantly higher in groups C and D than in group A at each time point (with t values from 15.167 to 98.074, P values below 0.01). The protein expression of NF-κB p65 in group D was obviously lower than that of group C at each time point (with t values from -37.190 to -14.415, P values below 0.01). The protein expression of NF-κB p65 in groups C and D both showed a trend of increase earlier and decrease later, and it peaked at PIH 12, respectively 4.46 ± 0.12 and 2.94 ± 0.21.

CONCLUSIONSParenteral supply of DHA to rats with severe scald injury can reduce the levels of TNF-α, IL-6, and LTB4 in serum and decrease the expression of NF-κB in pulmonary tissue, thus alleviating the inflammation response.

Animals ; Blotting, Western ; Burns ; Cytokines ; Docosahexaenoic Acids ; Enzyme-Linked Immunosorbent Assay ; Inflammation ; Interleukin-6 ; blood ; Leukotriene B4 ; blood ; Lung ; metabolism ; pathology ; NF-kappa B ; metabolism ; Rats ; Rats, Sprague-Dawley ; Serum ; Soft Tissue Injuries ; Tumor Necrosis Factor-alpha ; blood ; genetics ; Up-Regulation ; physiology

12(S)-Hydroxyheptadeca-5Z,8E,10E-trienoic acid (12-HHT) is an enzymatic product of prostaglandin H2 (PGH2) derived from cyclooxygenase (COX)-mediated arachidonic acid metabolism. Despite the high level of 12-HHT present in tissues and bodily fluids, its precise function remains largely unknown. In this study, we found that 12-HHT treatment in HaCaT cells remarkably down-regulated the ultraviolet B (UVB) irradiation-induced synthesis of interleukin-6 (IL-6), a pro-inflammatory cytokine associated with cutaneous inflammation. In an approach to identify the down-stream signaling mechanism by which 12-HHT down-regulates UVB-induced IL-6 synthesis in keratinocytes, we observed that 12-HHT inhibits the UVB-stimulated activation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-kappaB). In addition, we found that 12-HHT markedly up-regulates MAPK phosphatase-1 (MKP-1), a critical negative regulator of p38 MAPK. When MKP-1 was suppressed by siRNA knock-down, the 12-HHT-mediated inhibitory effects on the UVB-stimulated activation of p38 MAPK and NF-kappaB, as well as the production of IL-6, were attenuated in HaCaT cells. Taken together, our results suggest that 12-HHT exerts anti-inflammatory effect via up-regulation of MKP-1, which negatively regulates p38 MAPK and NF-kappaB, thus attenuating IL-6 production in UVB-irradiated HaCaT cells. Considering the critical role of IL-6 in cutaneous inflammation, our findings provide the basis for the application of 12-HHT as a potential anti-inflammatory therapeutic agent in UV-induced skin diseases.
Anti-Inflammatory Agents, Non-Steroidal/pharmacology ; Cell Line ; Dual Specificity Phosphatase 1/biosynthesis/genetics ; Enzyme Activation ; Fatty Acids, Unsaturated/*pharmacology ; Humans ; Interleukin-6/*biosynthesis ; Keratinocytes/*metabolism/radiation effects ; NF-kappa B/metabolism ; RNA Interference ; RNA, Small Interfering ; Receptors, Leukotriene B4/genetics ; Signal Transduction/drug effects ; Skin Diseases/drug therapy ; *Ultraviolet Rays ; Up-Regulation ; p38 Mitogen-Activated Protein Kinases/metabolism

A variety of benzylidenethiazole analogs have been demonstrated to inhibit 5-lipoxygenase (5-LOX). Here we report the anti-atherogenic potential of 5-(4-hydroxy-2,3,5-trimethylbenzylidene) thiazolidin-2,4-dione (HMB-TZD), a benzylidenethiazole analog, and its potential mechanism of action in LDL receptor-deficient (Ldlr-/-) mice. HMB-TZD Treatment reduced leukotriene B4 (LTB4) production significantly in RAW264.7 macrophages and SVEC4-10 endothelial cells. Macrophages or endothelial cells pre-incubated with HMB-TZD for 2 h and then stimulated with lipopolysaccharide or tumor necrosis factor-alpha (TNF-alpha) displayed reduced cytokine production. Also, HMB-TZD reduced cell migration and adhesion in accordance with decreased proinflammatory molecule production in vitro and ex vivo. HMB-TZD treatment of 8-week-old male Ldlr-/- mice resulted in significantly reduced atherosclerotic lesions without a change to plasma lipid profiles. Moreover, aortic expression of pro-atherogenic molecules involved in the recruitment of monocytes to the aortic wall, including TNF-alpha , MCP-1, and VCAM-1, was downregulated. HMB-TZD also reduced macrophage infiltration into atherosclerotic lesions. In conclusion, HMB-TZD ameliorates atherosclerotic lesion formation possibly by reducing the expression of proinflammatory molecules and monocyte/macrophage recruitment to the lesion. These results suggest that HMB-TZD, and benzylidenethiazole analogs in general, may have therapeutic potential as treatments for atherosclerosis.
Animals ; Atherosclerosis/*drug therapy ; Cell Adhesion/drug effects ; Cell Line ; Cell Movement/drug effects ; Chemokine CCL2/metabolism ; Dinoprostone/metabolism ; Enzyme-Linked Immunosorbent Assay ; Humans ; Leukotriene B4/metabolism ; Macrophages/cytology/drug effects ; Male ; Mice ; Monocytes/cytology/*drug effects ; Random Allocation ; Receptors, LDL/deficiency/genetics ; Thiazolidinediones/*therapeutic use ; Tumor Necrosis Factor-alpha/pharmacology

The incidence rates of urinary bladder cancer continue to rise yearly, and thus new therapeutic approaches and early diagnostic markers for bladder cancer are urgently needed. Thus, identifying the key mediators and molecular mechanisms responsible for the survival of bladder cancer has valuable implications for the development of therapy. In this study, the role of BLT2, a receptor for leukotriene B4 (LTB4) and 12(S)-hydroxyeicosatetraenoic acid (HETE), in the survival of bladder cancer 253J-BV cells was investigated. We found that the expression of BLT2 is highly elevated in bladder cancer cells. Also, we observed that blockade of BLT2 with an antagonist or BLT2 siRNA resulted in cell cycle arrest and apoptotic cell death, suggesting a role of BLT2 in the survival of human bladder cancer 253J-BV cells. Further experiments aimed at elucidating the mechanism by which BLT2 mediates survival revealed that enhanced level of reactive oxygen species (ROS) are generated via a BLT2-dependent up-regulation of NADPH oxidase members NOX1 and NOX4. Additionally, we observed that inhibition of ROS generation by either NOX1/4 siRNAs or treatment with an ROS-scavenging agent results in apoptotic cell death in 253J-BV bladder cancer cells. These results demonstrated that a 'BLT2-NOX1/4-ROS' cascade plays a role in the survival of this aggressive bladder cancer cells, thus pointing to BLT2 as a potential target for anti-bladder cancer therapy.
*Apoptosis ; Blotting, Western ; Cell Proliferation ; Cells, Cultured ; Gene Expression Regulation, Neoplastic/*physiology ; Humans ; Leukotriene Antagonists/pharmacology ; NADPH Oxidase/antagonists & inhibitors/genetics/metabolism ; Phosphorylation ; RNA, Messenger/genetics ; RNA, Small Interfering/genetics ; Reactive Oxygen Species/*metabolism ; Receptors, Leukotriene B4/antagonists & inhibitors/*genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; Tetrazoles/pharmacology ; Up-Regulation ; Urinary Bladder Neoplasms/*genetics/mortality