BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is associated with obesity,insulin resistance and dyslipidaemia and currently is estimated to affect up to a third of all individuals in developed countries.Current s...BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is associated with obesity,insulin resistance and dyslipidaemia and currently is estimated to affect up to a third of all individuals in developed countries.Current standard of care for patients varies according to disease stage,but includes lifestyle interventions common insulin sensitizers,antioxidants and lipid modifiers.However,to date specific therapies have shown little histological or fibrosis stage improvement in large clinical trials,and there is still no licensed therapy for NAFLD.Given the high prevalence,limited treatment options and significant screening costs for the general population,new treatments are urgently required.AIM To assess the potential for inhibition of the amine oxidase enzyme vascular adhesion protein-1(VAP-1)to modify hepatic lipid accumulation in NAFLD.METHODS We have used immunochemical and qPCR analysis to document expression of VAP-1 and key functional proteins and transporters across the NAFLD spectrum.We then utilised hepatocytes in culture and human precision cut liver slices in concert with selective enzyme activity inhibitors to test the effects of activating the semicarbazide-sensitive amine oxidase activity of VAP-1 on hepatic lipid uptake and triglyceride export.A murine model of NAFLD was also used to determine the consequences of VAP-1 knockout and gene expression arrays were used to quantify the effects of VAP-1 activity on key lipid modifying and proinflammatory gene expression.RESULTS We confirmed that increasing severity of NAFLD and progression to cirrhosis was associated with a significant increase in hepatocellular VAP-1 expression.Hepatocytes in vitro exposed to recombinant VAP-1 and its substrate methylamine showed increased lipid accumulation as determined by quantification of Oil Red O uptake.This was recapitulated using hydrogen peroxide,and lipid accumulation was accompanied by changes in expression of the lipid transporter molecules FABP3,FATP6,insulin receptor subunits and PPARα.Human liver tissue exposed to recombinant VAP-1 or substrates for endo/exogenous VAP-1 produced less triglyceride than untreated tissue and demonstrated an increase in steatosis.This response could be inhibited by using bromoethylamine to inhibit the SSAO activity of VAP-1,and mice deficient in VAP-1/AOC3 also demonstrated reduced steatosis on high fat diet.Exposure of human liver tissue to methylamine to activate VAP-1 resulted in increased expression of FABP2 and 4,FATP3-5,caveolin-1,VLDLR,PPARGC1 and genes associated with the inflammatory response.CONCLUSION Our data confirm that the elevations in hepatic VAP-1 expression reported in nonalcoholic steatohepatitis can contribute to steatosis,metabolic disturbance and inflammation.This suggests that targeting the semicarbazide sensitive amine oxidase capacity of VAP-1 may represent a useful adjunct to other therapeutic strategies in NAFLD.展开更多
目的:通过分析狼疮肾炎患者血Fractalkine(FKN)以及尿血管细胞黏附分子-1(vascular cellular adhesion molecule-1,VCAM-1)的水平及实验室常用指标与中医风湿内扰证候之间的关系。方法:对确诊为66例狼疮肾炎患者进行辨证分型分为风湿内...目的:通过分析狼疮肾炎患者血Fractalkine(FKN)以及尿血管细胞黏附分子-1(vascular cellular adhesion molecule-1,VCAM-1)的水平及实验室常用指标与中医风湿内扰证候之间的关系。方法:对确诊为66例狼疮肾炎患者进行辨证分型分为风湿内扰组36例及非风湿内扰组30例。另选取健康体检的正常人20例作为对照组,收集临床资料及实验室指标并同步留取血、尿标本,ELISA法检测86例标本血Fractalkine与尿VCAM-1水平,综合分析风湿内扰证候与上述指标之间的关系。结果:(1)风湿内扰组患者较非风湿内扰组易出现发热乏力(45.8%VS 19.2%)、关节炎(29.2%VS 3.8%)、高血压(35.9%VS 7.7%)、浮肿(41.7%VS 0%)(P<0.05);(2)风湿内扰组患者血Fractalkine(1.78±1.19 VS 0.94±0.83)及尿VCAM-1(62.37±27.65 VS 27.21±30.14)水平均显著高于非风湿内扰组(P<0.01);血红蛋白定量(113.29±29.21 VS 127.04±12.32)、血白蛋白定量(34.77±6.92 VS 43.33±3.08)均低于非风湿内扰组(P<0.05);风湿内扰组24 h尿蛋白定量水平(2170.01±1469.30 VS 278.25±178.86)、尿红细胞定量(10.00(0.75,20.00)VS 0.00(0.00,0.75))均高于非风湿内扰组,(P<0.01);风湿内扰组中血C3水平低于非风湿内扰组,ANA滴度、anti-dsDNA及anti-SM阳性率明显高于非风湿内扰组(P<0.05);风湿内扰组SLEDAI积分、BILAG积分均高于非风湿内扰组(P<0.01);(3)风湿内扰证候与血Fractalkine、尿VCAM-1、尿红细胞、24 h尿蛋白、SLEDAI积分、BILAG积分、ANA滴度呈正相关(P<0.01),与血白蛋白呈负相关(P<0.01)。(4)风湿内扰组病理类型以IV型及IV+V型为主。结论:狼疮肾炎风湿内扰证候与疾病活动度密切相关,当临床出现风湿内扰证时需警惕狼疮肾炎疾病的活动。展开更多
文摘BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is associated with obesity,insulin resistance and dyslipidaemia and currently is estimated to affect up to a third of all individuals in developed countries.Current standard of care for patients varies according to disease stage,but includes lifestyle interventions common insulin sensitizers,antioxidants and lipid modifiers.However,to date specific therapies have shown little histological or fibrosis stage improvement in large clinical trials,and there is still no licensed therapy for NAFLD.Given the high prevalence,limited treatment options and significant screening costs for the general population,new treatments are urgently required.AIM To assess the potential for inhibition of the amine oxidase enzyme vascular adhesion protein-1(VAP-1)to modify hepatic lipid accumulation in NAFLD.METHODS We have used immunochemical and qPCR analysis to document expression of VAP-1 and key functional proteins and transporters across the NAFLD spectrum.We then utilised hepatocytes in culture and human precision cut liver slices in concert with selective enzyme activity inhibitors to test the effects of activating the semicarbazide-sensitive amine oxidase activity of VAP-1 on hepatic lipid uptake and triglyceride export.A murine model of NAFLD was also used to determine the consequences of VAP-1 knockout and gene expression arrays were used to quantify the effects of VAP-1 activity on key lipid modifying and proinflammatory gene expression.RESULTS We confirmed that increasing severity of NAFLD and progression to cirrhosis was associated with a significant increase in hepatocellular VAP-1 expression.Hepatocytes in vitro exposed to recombinant VAP-1 and its substrate methylamine showed increased lipid accumulation as determined by quantification of Oil Red O uptake.This was recapitulated using hydrogen peroxide,and lipid accumulation was accompanied by changes in expression of the lipid transporter molecules FABP3,FATP6,insulin receptor subunits and PPARα.Human liver tissue exposed to recombinant VAP-1 or substrates for endo/exogenous VAP-1 produced less triglyceride than untreated tissue and demonstrated an increase in steatosis.This response could be inhibited by using bromoethylamine to inhibit the SSAO activity of VAP-1,and mice deficient in VAP-1/AOC3 also demonstrated reduced steatosis on high fat diet.Exposure of human liver tissue to methylamine to activate VAP-1 resulted in increased expression of FABP2 and 4,FATP3-5,caveolin-1,VLDLR,PPARGC1 and genes associated with the inflammatory response.CONCLUSION Our data confirm that the elevations in hepatic VAP-1 expression reported in nonalcoholic steatohepatitis can contribute to steatosis,metabolic disturbance and inflammation.This suggests that targeting the semicarbazide sensitive amine oxidase capacity of VAP-1 may represent a useful adjunct to other therapeutic strategies in NAFLD.
文摘目的:通过分析狼疮肾炎患者血Fractalkine(FKN)以及尿血管细胞黏附分子-1(vascular cellular adhesion molecule-1,VCAM-1)的水平及实验室常用指标与中医风湿内扰证候之间的关系。方法:对确诊为66例狼疮肾炎患者进行辨证分型分为风湿内扰组36例及非风湿内扰组30例。另选取健康体检的正常人20例作为对照组,收集临床资料及实验室指标并同步留取血、尿标本,ELISA法检测86例标本血Fractalkine与尿VCAM-1水平,综合分析风湿内扰证候与上述指标之间的关系。结果:(1)风湿内扰组患者较非风湿内扰组易出现发热乏力(45.8%VS 19.2%)、关节炎(29.2%VS 3.8%)、高血压(35.9%VS 7.7%)、浮肿(41.7%VS 0%)(P<0.05);(2)风湿内扰组患者血Fractalkine(1.78±1.19 VS 0.94±0.83)及尿VCAM-1(62.37±27.65 VS 27.21±30.14)水平均显著高于非风湿内扰组(P<0.01);血红蛋白定量(113.29±29.21 VS 127.04±12.32)、血白蛋白定量(34.77±6.92 VS 43.33±3.08)均低于非风湿内扰组(P<0.05);风湿内扰组24 h尿蛋白定量水平(2170.01±1469.30 VS 278.25±178.86)、尿红细胞定量(10.00(0.75,20.00)VS 0.00(0.00,0.75))均高于非风湿内扰组,(P<0.01);风湿内扰组中血C3水平低于非风湿内扰组,ANA滴度、anti-dsDNA及anti-SM阳性率明显高于非风湿内扰组(P<0.05);风湿内扰组SLEDAI积分、BILAG积分均高于非风湿内扰组(P<0.01);(3)风湿内扰证候与血Fractalkine、尿VCAM-1、尿红细胞、24 h尿蛋白、SLEDAI积分、BILAG积分、ANA滴度呈正相关(P<0.01),与血白蛋白呈负相关(P<0.01)。(4)风湿内扰组病理类型以IV型及IV+V型为主。结论:狼疮肾炎风湿内扰证候与疾病活动度密切相关,当临床出现风湿内扰证时需警惕狼疮肾炎疾病的活动。
