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
OBJECTIVE To investigate the mechanisms of histone deacetylase 6(HDAC6)deacetylation activity on NALP3 inflammasome activation and explore the protective effect s of pharmacological inhibition of HDAC6 on dopaminergic...OBJECTIVE To investigate the mechanisms of histone deacetylase 6(HDAC6)deacetylation activity on NALP3 inflammasome activation and explore the protective effect s of pharmacological inhibition of HDAC6 on dopaminergic injury.METHODS In vitro and in vivo6-OHDA induced Parkinson disease(PD) model was used.To distinguish the effect of deacetylase catalytic domains of HDAC6,we used a specific HDAC6 inhibitor tubastatin A(TBA),siRNAHDAC6,and pcDNA-HDAC6-FLAG plasmid.First,the role of pharmacological inhibition or siRNA or overexpression of HDAC6 on NALP3 inflammasome and cell death was explored by using Western blotting,TUNEL,and flow cytometric analysis.Then,the acetylation level of peroxiredoxin 2(Prx2) and the production of reactive oxygen species(ROS) in cells under different treatments was examined by using immunoprecipitation and DCFH-DA fluorescence assay.The effects of TBA on neuroinflammation and nigrostriatal dopaminergic system in vivo was further investigated by using Western blotting,immunohistochemistry and HPLC analysis.RESULTS TBA remarkably inhibited 6-OHDA induced NALP3 inflammasome activation,reduced dopaminergic neurodegeneration and neuroinflammation as demonstrated by increased TH-positive neurons,striatal levels of DA and its metabolites,and decreased gliocyte proliferation.TBA recovered acetylation of Prx2,and reduced ROS production,which was associated with decreased NALP3 inflammasome activation.CONCLUSION HDAC6 may medicate deacetylation of Prx2 contributes to NALP3 inflammasome activation in PD pathology,suggesting that the development of specific pharmacological inhibitors of HDAC6 be required for this kind of disease.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.
基金Key Technologies Research and Development Program of Shandong Province (2017GSF18171,2018GSF118139).
文摘OBJECTIVE To investigate the mechanisms of histone deacetylase 6(HDAC6)deacetylation activity on NALP3 inflammasome activation and explore the protective effect s of pharmacological inhibition of HDAC6 on dopaminergic injury.METHODS In vitro and in vivo6-OHDA induced Parkinson disease(PD) model was used.To distinguish the effect of deacetylase catalytic domains of HDAC6,we used a specific HDAC6 inhibitor tubastatin A(TBA),siRNAHDAC6,and pcDNA-HDAC6-FLAG plasmid.First,the role of pharmacological inhibition or siRNA or overexpression of HDAC6 on NALP3 inflammasome and cell death was explored by using Western blotting,TUNEL,and flow cytometric analysis.Then,the acetylation level of peroxiredoxin 2(Prx2) and the production of reactive oxygen species(ROS) in cells under different treatments was examined by using immunoprecipitation and DCFH-DA fluorescence assay.The effects of TBA on neuroinflammation and nigrostriatal dopaminergic system in vivo was further investigated by using Western blotting,immunohistochemistry and HPLC analysis.RESULTS TBA remarkably inhibited 6-OHDA induced NALP3 inflammasome activation,reduced dopaminergic neurodegeneration and neuroinflammation as demonstrated by increased TH-positive neurons,striatal levels of DA and its metabolites,and decreased gliocyte proliferation.TBA recovered acetylation of Prx2,and reduced ROS production,which was associated with decreased NALP3 inflammasome activation.CONCLUSION HDAC6 may medicate deacetylation of Prx2 contributes to NALP3 inflammasome activation in PD pathology,suggesting that the development of specific pharmacological inhibitors of HDAC6 be required for this kind of disease.
