OBJECTIVE Leukotriene B4(LTB4)biosynthesis and subsequently neutrophilic inflammation may provide a potential strategy for the treatment of acute lung injury(ALI)or idiopathic pulmonary fibrosis(IPF).To provide a pote...OBJECTIVE Leukotriene B4(LTB4)biosynthesis and subsequently neutrophilic inflammation may provide a potential strategy for the treatment of acute lung injury(ALI)or idiopathic pulmonary fibrosis(IPF).To provide a potential strategy for the treatment of ALI or IPF,we identified potent inhibitors of Leukotriene A4 hydrolase(LTA4H),a key enzyme in the biosynthesis of LTB4.METHODS In this study,we identified two known histone deacetylase(HDAC)inhibitors,suberanilohydroxamic acid(SAHA)and its analogue 4-(dimethylamino)-N-[7-(hydroxyamino)-7-oxoheptyl]benzamide(M344),as effective inhibitors of LTA4H using enzymatic assay,thermofluor assay,and X-ray crystallographic investigation.We next tested the effect of SAHA and M344 on endogenous LTB4 biosynthesis in neutrophils by ELISA and neutrophil migration by transwell migration assay.A murine experimental model of ALI was induced by lipopolysaccharide(LPS)inhalation.Histopathological analysis of lung tissue using H&E staining revealed the serious pulmonary damage caused by LPS treatment and the effect of the SAHA.We next examined m RNA and protein levels of pro-inflammatory cytokines in lung tissue and bronchoalveolar lavage fluid using q RT-PCR and ELISA to further investigate the underlying mechanisms of anti-inflammatory activities by SAHA.We also investigated the effects of SAHA and M344 on a murine experimental model of bleomycin(BLM)-induced IPF model.RESULTS The results of enzymatic assay and X-ray crystallography showed that both SAHA and M344 bind to LTA4H,significantly decrease LTB4 levels in neutrophil,and markedly diminish early neutrophilic inflammation in mouse models of ALI and IPF under a clinical safety dose.CONCLUSION Collectively,SAHA and M344 would provide promising agents with well-known clinical safety for potential treatment in patients with ALI and IPF via pharmacologically inhibiting LAT4H and blocking LTB4 biosynthesis.展开更多
Trichomoniasis is most common sexually transmitted disease caused by T. vaginalis. The clinical manifestation varies from severe manifestation to asymptomatic condition. However, the exact virulence markers led to var...Trichomoniasis is most common sexually transmitted disease caused by T. vaginalis. The clinical manifestation varies from severe manifestation to asymptomatic condition. However, the exact virulence markers led to varied symptomatology was not well clarified. The role of leukotriene B4 (LTB4) in the pathogenesis of many parasitic diseases has been reported. The present study reports the leukotriene B4 levels on different days post infection (3rd, 7th, 14th, 21st and 28th d.p.i.) in serum and vaginal washes (VWs) and vaginal tissues of mice infected intravaginally with T. vaginalis isolates from 10 symptomatic and 10 asymptomatic women. A significant increase in LTB4 was observed on the 3rd to 28th d.p.i. in serum and VWs of mice infected with T. vaginalis isolates from asymptomatic as compared to symptomatic women. The present study also reports the histopathological changes of the posterior vaginal fornix’s and upper portion of the vagina of mice infected intravaginally with T. vaginalis isolates from 10 symptomatic and 10 asymptomatic women. The results show that there are no significant differences between symptomatic and asymptomatic isolates regarding histopathological changes.展开更多
Modification was made on the reversed-phase high performance liquid chromatography(RP-HPLC)with Yue et al's method as a base.The modified RP-HPLC was used to detect leukotriene B_4(LTB_4)and 5-hydroxyeicosatetraen...Modification was made on the reversed-phase high performance liquid chromatography(RP-HPLC)with Yue et al's method as a base.The modified RP-HPLC was used to detect leukotriene B_4(LTB_4)and 5-hydroxyeicosatetraenoic acid(5-HETE).It was found that the modified method has the merits of simpler procedures,shorter testing time and more satisfactory efficacy.展开更多
To investigate the relationship between tendinopathy and higher production of prostaglandins E2 (PGE2) and leukotriene B4(LTB4) induced by cyclic stretching of human patellar tendon fibroblasts.Methods We used a novel...To investigate the relationship between tendinopathy and higher production of prostaglandins E2 (PGE2) and leukotriene B4(LTB4) induced by cyclic stretching of human patellar tendon fibroblasts.Methods We used a novel in vitro model system to mimic in vivo conditions,where human patellar tendon fibroblasts (HPTFs) were uniaxially stretched with different magnitudes of stretching (4%,8% and 12%).Non-stretched fibroblasts were used as control.The productions of PGE2 and LTB4 as well as the expression of cycloxygenase (COX) and 5-lipoxygenase (5-LO) were then measured every four hours of cyclic stretching.In addition,we treated the cells with inhibitors of COX or 5-LO.Results It was found that cyclic stretching of fibroblasts at 8% and 12% of stretching increased PGE2 and LTB4 levels.Blocking the COX enzyme with indomethacin (25 mol/L) decreased PGE2 levels but increased LTB4 production and vice versa.Whereas decreasing LTB4 production with MK-886 (10 μmol/L) could increase PGE2 levels compared to cells tretched without inhibitors.Conclusion Cyclic stretching of HPTFs produces high levels of PGE2 and LTB4,where a balance exists:blocking PGE2 production increases the production of LTB4,and vice versa.Therefore,this study raises the possibility that the routine use of COX inhibitors in clinical treatment of tendinopathy may exacerbate the condition by causing neutrophil-mediated inflammatory and degenerative changes in the tendon due to increased levels of LTB4,which is a potent chemoattractant for neutrophils.17 refs,3 figs.展开更多
Background and Objective:LTB4 has been shown to be involved in rheumatoid arthritis(RA)pathogenesis.The effect of Dioscin(Dio)on the LTB4 pathway of RA have not been reported yet.This study aimed at further exploring ...Background and Objective:LTB4 has been shown to be involved in rheumatoid arthritis(RA)pathogenesis.The effect of Dioscin(Dio)on the LTB4 pathway of RA have not been reported yet.This study aimed at further exploring whether Dioscin’s effects on TNF-αinduced collagen-induced arthritis(CIA)rat fibroblast-like synoviocytes(FLS)connected with the LTB4 and its receptor pathway.Materials&Methods:In this experiment,control group,TNF-αgroup,and different concentrations of Dioscin groups were established.Cell viability was evaluated using MTT assay.The levels of LTB4 in the samples of above groups were measured using ELISA.The mRNA expression levels of LTA4H,BLT1,and BLT2 were detected by quantitative real time PCR,while the expression level of LTA4H proteins were detected using western blot.The distribution of LTA4H was assessed by immunofluorescence assay.Results:the LTB4 level of TNF-αgroup in sample supernatant was higher than both control group and Dioscin groups with decreased LTB4 levels(p<0.05).Compared with the control group,the expression of LTA4H was significantly increased in TNF-αgroup(p<0.05),whereas LTA4H expressions were significantly decreased in all Dioscin groups when compared to TNF-αgroup(p<0.05).The mRNA expressions of BLT1 and BLT2 were markedly higher in TNF-αgroup than those in control group while Dioscin treatment significantly inhibited the increased expressions of BLT1 and BLT2 induced by TNF-α(p<0.05).Conclusions:These results firstly demonstrate that the protective effect of Dioscin on TNF-αinduced FLS may involve in its reducing LTB4 production by down-regulating LTA4H expression,and may inhibit its downstream pathway by decreasing LTB4 receptors levels.This findings suggest that dioscin produces a potential therapeutic effects for RA via its influencing LTA4H/LTB4/BLT pathway.展开更多
AIM: To investigate the effects of a novel Leukotriene B4 receptor antagonist and/or tacrolimus on ischemia-reperfusion in a rat liver model. METHODS: Male Lewis rats were pretreated with ONO-4057 (100 mg/kg) and/or t...AIM: To investigate the effects of a novel Leukotriene B4 receptor antagonist and/or tacrolimus on ischemia-reperfusion in a rat liver model. METHODS: Male Lewis rats were pretreated with ONO-4057 (100 mg/kg) and/or tacrolimus (1 mg/kg) orally, and divided into four experimental groups; group 1 (control), group 2 (ONO-4057), group 3 (tacrolimus), group 4 (ONO-4057 + tacrolimus). RESULTS: There was a tendency for long survival in the groups treated with tacrolimus alone and ONO-4057 plus tacrolimus. Post-reperfusion serum aspartate aminotransferase levels decreased more signif icantly in ONO-4057 plus tacrolimus group (P < 0.01), than in the tacrolimus alone group (P < 0.05), compared to controls. CONCLUSION: This study demonstrated that pretreat-ment with ONO-4057 in combination with tacrolimus produced additive effects in a rat model of liver isch-emia-reperfusion injury.展开更多
Chengqi mixture (CM) is a Chinese herbal mixture valuable in treating acute peritonitis.The anti-inflammatory action of Chengqi mixture was investigated on the synthesis of leukotriene B4(LTB4) and shydroxyeicosatetra...Chengqi mixture (CM) is a Chinese herbal mixture valuable in treating acute peritonitis.The anti-inflammatory action of Chengqi mixture was investigated on the synthesis of leukotriene B4(LTB4) and shydroxyeicosatetraenoic acid (5-HETE) of peritoneal macrophages in rats. These mediatorswere determined by Reverse Phase-High Performance Liquid Chromatography. The ultraviolet absorbanceot LTB4 was 280 nm, and of 5-HETE was 235 nm. The results indicated ditferent concentrations ot CM sig-nificantly inhibited the synthesis of LTB4 compared with the control (P<0. 01, n=16) and were dose de-pendent from 0. 15 to 10 g/L. The inhibitory rate of CM for the LTB4 exceeded 95% and for 5-HETE wasabout 70% at the dose of 5 g/L. The inhibitory rate of CM was equal to that of the flutenamic acid groupin which the final concentration was at 10-4M. The half inhibitory rates (IC50) of CM for LTB4 and that for 5-HETE were 0. 8 g/L and 1.1 g/L respectively. It is suggested that the anti-inflammatory actions of CMwas related to the inhibition of synthesis of LTB4 and SHETE from arachidonic acid via 5-lipoxygenase inmacrophages.展开更多
Objective: To study the therapeutic mechanism of Santeng Dingtong recipe (STDT) on monosodium urate crystal (MSU) induced rabbit arthritis Methods: Forty-two rabbits were randomly divided into six groups, 7 in each gr...Objective: To study the therapeutic mechanism of Santeng Dingtong recipe (STDT) on monosodium urate crystal (MSU) induced rabbit arthritis Methods: Forty-two rabbits were randomly divided into six groups, 7 in each group. Group 1 received 0.9% saline 2. 5 ml/kg per day by gastrogavage (ig) for 10 days; Group 2, 3 and 4 received STDT 0.125 g/kg, 1.0 g/kg and 8.0 g/kg per day respectively by ig for 10 days; Group 5 received colchicine 4. 5 mg/kg per day by ig for 4 days; and Group 6 was untreated. MSU crystals 10 mg /500ul containing polymyxin B 10 u/ml was injected into the knee joints of Group 1-5 to make rabbit arthritis models. Leukocytes in synovial lavage fluids was then counted and differentiated; pathological injury of synovial membranes was observed under HE staining; interleukin-1 beta (IL-1B), tumor necrosis factor alpha (TNFa) and leukotriene B4 (LTB4) content in synovial lavage fluids were determined by ELISA. Results: MSU caused a rapid leukocyte infiltration and increased production of IL-1B, TNFa and LTB4 2 hrs after intra-articular injection. STDT inhibited neutrophil infiltration in synovial fluids dose-dependently, protected the synovial membrane against pathological injury and reduced the production of IL-1B, TNFa and LTB4; while colchicine did not decrease the level of TNFa, but significantly inhibited neutrophil infiltration in synovial fluid and reduced the production of IL-11B and LTB4. Conclusion: STDT exerts an anti-inflammatory effect in rabbit model of acute MSU arthritis, its mechanism being probably due to the decrease of XL-1B, TNFa and LTB4 synthesis.展开更多
基金supported by National Natural Science Foundation of China(81402482,91313303)
文摘OBJECTIVE Leukotriene B4(LTB4)biosynthesis and subsequently neutrophilic inflammation may provide a potential strategy for the treatment of acute lung injury(ALI)or idiopathic pulmonary fibrosis(IPF).To provide a potential strategy for the treatment of ALI or IPF,we identified potent inhibitors of Leukotriene A4 hydrolase(LTA4H),a key enzyme in the biosynthesis of LTB4.METHODS In this study,we identified two known histone deacetylase(HDAC)inhibitors,suberanilohydroxamic acid(SAHA)and its analogue 4-(dimethylamino)-N-[7-(hydroxyamino)-7-oxoheptyl]benzamide(M344),as effective inhibitors of LTA4H using enzymatic assay,thermofluor assay,and X-ray crystallographic investigation.We next tested the effect of SAHA and M344 on endogenous LTB4 biosynthesis in neutrophils by ELISA and neutrophil migration by transwell migration assay.A murine experimental model of ALI was induced by lipopolysaccharide(LPS)inhalation.Histopathological analysis of lung tissue using H&E staining revealed the serious pulmonary damage caused by LPS treatment and the effect of the SAHA.We next examined m RNA and protein levels of pro-inflammatory cytokines in lung tissue and bronchoalveolar lavage fluid using q RT-PCR and ELISA to further investigate the underlying mechanisms of anti-inflammatory activities by SAHA.We also investigated the effects of SAHA and M344 on a murine experimental model of bleomycin(BLM)-induced IPF model.RESULTS The results of enzymatic assay and X-ray crystallography showed that both SAHA and M344 bind to LTA4H,significantly decrease LTB4 levels in neutrophil,and markedly diminish early neutrophilic inflammation in mouse models of ALI and IPF under a clinical safety dose.CONCLUSION Collectively,SAHA and M344 would provide promising agents with well-known clinical safety for potential treatment in patients with ALI and IPF via pharmacologically inhibiting LAT4H and blocking LTB4 biosynthesis.
文摘Trichomoniasis is most common sexually transmitted disease caused by T. vaginalis. The clinical manifestation varies from severe manifestation to asymptomatic condition. However, the exact virulence markers led to varied symptomatology was not well clarified. The role of leukotriene B4 (LTB4) in the pathogenesis of many parasitic diseases has been reported. The present study reports the leukotriene B4 levels on different days post infection (3rd, 7th, 14th, 21st and 28th d.p.i.) in serum and vaginal washes (VWs) and vaginal tissues of mice infected intravaginally with T. vaginalis isolates from 10 symptomatic and 10 asymptomatic women. A significant increase in LTB4 was observed on the 3rd to 28th d.p.i. in serum and VWs of mice infected with T. vaginalis isolates from asymptomatic as compared to symptomatic women. The present study also reports the histopathological changes of the posterior vaginal fornix’s and upper portion of the vagina of mice infected intravaginally with T. vaginalis isolates from 10 symptomatic and 10 asymptomatic women. The results show that there are no significant differences between symptomatic and asymptomatic isolates regarding histopathological changes.
文摘Modification was made on the reversed-phase high performance liquid chromatography(RP-HPLC)with Yue et al's method as a base.The modified RP-HPLC was used to detect leukotriene B_4(LTB_4)and 5-hydroxyeicosatetraenoic acid(5-HETE).It was found that the modified method has the merits of simpler procedures,shorter testing time and more satisfactory efficacy.
文摘To investigate the relationship between tendinopathy and higher production of prostaglandins E2 (PGE2) and leukotriene B4(LTB4) induced by cyclic stretching of human patellar tendon fibroblasts.Methods We used a novel in vitro model system to mimic in vivo conditions,where human patellar tendon fibroblasts (HPTFs) were uniaxially stretched with different magnitudes of stretching (4%,8% and 12%).Non-stretched fibroblasts were used as control.The productions of PGE2 and LTB4 as well as the expression of cycloxygenase (COX) and 5-lipoxygenase (5-LO) were then measured every four hours of cyclic stretching.In addition,we treated the cells with inhibitors of COX or 5-LO.Results It was found that cyclic stretching of fibroblasts at 8% and 12% of stretching increased PGE2 and LTB4 levels.Blocking the COX enzyme with indomethacin (25 mol/L) decreased PGE2 levels but increased LTB4 production and vice versa.Whereas decreasing LTB4 production with MK-886 (10 μmol/L) could increase PGE2 levels compared to cells tretched without inhibitors.Conclusion Cyclic stretching of HPTFs produces high levels of PGE2 and LTB4,where a balance exists:blocking PGE2 production increases the production of LTB4,and vice versa.Therefore,this study raises the possibility that the routine use of COX inhibitors in clinical treatment of tendinopathy may exacerbate the condition by causing neutrophil-mediated inflammatory and degenerative changes in the tendon due to increased levels of LTB4,which is a potent chemoattractant for neutrophils.17 refs,3 figs.
基金supported by the National Natural Science Foundation of China(Nos.82060661,81660751,81660151)Jiangxi Provincial Natural Science Foundation of China(No.20171BAB205085).
文摘Background and Objective:LTB4 has been shown to be involved in rheumatoid arthritis(RA)pathogenesis.The effect of Dioscin(Dio)on the LTB4 pathway of RA have not been reported yet.This study aimed at further exploring whether Dioscin’s effects on TNF-αinduced collagen-induced arthritis(CIA)rat fibroblast-like synoviocytes(FLS)connected with the LTB4 and its receptor pathway.Materials&Methods:In this experiment,control group,TNF-αgroup,and different concentrations of Dioscin groups were established.Cell viability was evaluated using MTT assay.The levels of LTB4 in the samples of above groups were measured using ELISA.The mRNA expression levels of LTA4H,BLT1,and BLT2 were detected by quantitative real time PCR,while the expression level of LTA4H proteins were detected using western blot.The distribution of LTA4H was assessed by immunofluorescence assay.Results:the LTB4 level of TNF-αgroup in sample supernatant was higher than both control group and Dioscin groups with decreased LTB4 levels(p<0.05).Compared with the control group,the expression of LTA4H was significantly increased in TNF-αgroup(p<0.05),whereas LTA4H expressions were significantly decreased in all Dioscin groups when compared to TNF-αgroup(p<0.05).The mRNA expressions of BLT1 and BLT2 were markedly higher in TNF-αgroup than those in control group while Dioscin treatment significantly inhibited the increased expressions of BLT1 and BLT2 induced by TNF-α(p<0.05).Conclusions:These results firstly demonstrate that the protective effect of Dioscin on TNF-αinduced FLS may involve in its reducing LTB4 production by down-regulating LTA4H expression,and may inhibit its downstream pathway by decreasing LTB4 receptors levels.This findings suggest that dioscin produces a potential therapeutic effects for RA via its influencing LTA4H/LTB4/BLT pathway.
文摘AIM: To investigate the effects of a novel Leukotriene B4 receptor antagonist and/or tacrolimus on ischemia-reperfusion in a rat liver model. METHODS: Male Lewis rats were pretreated with ONO-4057 (100 mg/kg) and/or tacrolimus (1 mg/kg) orally, and divided into four experimental groups; group 1 (control), group 2 (ONO-4057), group 3 (tacrolimus), group 4 (ONO-4057 + tacrolimus). RESULTS: There was a tendency for long survival in the groups treated with tacrolimus alone and ONO-4057 plus tacrolimus. Post-reperfusion serum aspartate aminotransferase levels decreased more signif icantly in ONO-4057 plus tacrolimus group (P < 0.01), than in the tacrolimus alone group (P < 0.05), compared to controls. CONCLUSION: This study demonstrated that pretreat-ment with ONO-4057 in combination with tacrolimus produced additive effects in a rat model of liver isch-emia-reperfusion injury.
文摘Chengqi mixture (CM) is a Chinese herbal mixture valuable in treating acute peritonitis.The anti-inflammatory action of Chengqi mixture was investigated on the synthesis of leukotriene B4(LTB4) and shydroxyeicosatetraenoic acid (5-HETE) of peritoneal macrophages in rats. These mediatorswere determined by Reverse Phase-High Performance Liquid Chromatography. The ultraviolet absorbanceot LTB4 was 280 nm, and of 5-HETE was 235 nm. The results indicated ditferent concentrations ot CM sig-nificantly inhibited the synthesis of LTB4 compared with the control (P<0. 01, n=16) and were dose de-pendent from 0. 15 to 10 g/L. The inhibitory rate of CM for the LTB4 exceeded 95% and for 5-HETE wasabout 70% at the dose of 5 g/L. The inhibitory rate of CM was equal to that of the flutenamic acid groupin which the final concentration was at 10-4M. The half inhibitory rates (IC50) of CM for LTB4 and that for 5-HETE were 0. 8 g/L and 1.1 g/L respectively. It is suggested that the anti-inflammatory actions of CMwas related to the inhibition of synthesis of LTB4 and SHETE from arachidonic acid via 5-lipoxygenase inmacrophages.
基金This program was supported by the National New Drugs Foundation(No.98-35-N-13)
文摘Objective: To study the therapeutic mechanism of Santeng Dingtong recipe (STDT) on monosodium urate crystal (MSU) induced rabbit arthritis Methods: Forty-two rabbits were randomly divided into six groups, 7 in each group. Group 1 received 0.9% saline 2. 5 ml/kg per day by gastrogavage (ig) for 10 days; Group 2, 3 and 4 received STDT 0.125 g/kg, 1.0 g/kg and 8.0 g/kg per day respectively by ig for 10 days; Group 5 received colchicine 4. 5 mg/kg per day by ig for 4 days; and Group 6 was untreated. MSU crystals 10 mg /500ul containing polymyxin B 10 u/ml was injected into the knee joints of Group 1-5 to make rabbit arthritis models. Leukocytes in synovial lavage fluids was then counted and differentiated; pathological injury of synovial membranes was observed under HE staining; interleukin-1 beta (IL-1B), tumor necrosis factor alpha (TNFa) and leukotriene B4 (LTB4) content in synovial lavage fluids were determined by ELISA. Results: MSU caused a rapid leukocyte infiltration and increased production of IL-1B, TNFa and LTB4 2 hrs after intra-articular injection. STDT inhibited neutrophil infiltration in synovial fluids dose-dependently, protected the synovial membrane against pathological injury and reduced the production of IL-1B, TNFa and LTB4; while colchicine did not decrease the level of TNFa, but significantly inhibited neutrophil infiltration in synovial fluid and reduced the production of IL-11B and LTB4. Conclusion: STDT exerts an anti-inflammatory effect in rabbit model of acute MSU arthritis, its mechanism being probably due to the decrease of XL-1B, TNFa and LTB4 synthesis.
