BACKGROUND Zinc-α2-glycoprotein 1 (AZGP1) plays important roles in metabolism-related diseases. The underlying molecular mechanisms and therapeutic effects of AZGP1 remain unknown in non-alcoholic fatty liver disease...BACKGROUND Zinc-α2-glycoprotein 1 (AZGP1) plays important roles in metabolism-related diseases. The underlying molecular mechanisms and therapeutic effects of AZGP1 remain unknown in non-alcoholic fatty liver disease (NAFLD). AIM To explore the effects and potential mechanism of AZGP1 on NAFLD in vivo and in vitro. METHODS The expression of AZGP1 and its effects on hepatocytes were examined in NAFLD patients, CCl4-treated mice fed a high fat diet (HFD), and human LO2 cells. RESULTS AZGP1 levels were significantly decreased in liver tissues of NAFLD patients and mice. AZGP1 knockdown was found to activate inflammation;enhance steatogenesis, including promoting lipogenesis [sterol regulatory elementbinding protein (SREBP)-1c, liver X receptor (LXR), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and stearoyl CoA desaturase 1 (SCD)-1], increasing lipid transport and accumulation [fatty acid transport protein (FATP), carnitine palmitoyl transferase (CPT)-1A, and adiponectin], and reducing fatty acid β-oxidation [farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor (PPAR)-α];accelerate proliferation;and reverse apoptosis in LO2 cells. AZGP1 overexpression (OV-AZGP1) had the opposite effects. Furthermore, AZGP1 alleviated NAFLD by blocking TNF-α-mediated inflammation and intracellular lipid deposition, promoting proliferation, and inhibiting apoptosis in LO2 cells. Finally, treatment with OV-AZGP1 plasmid dramatically improved liver injury and eliminated liver fat in NAFLD mice. CONCLUSION AZGP1 attenuates NAFLD with regard to ameliorating inflammation, accelerating lipolysis, promoting proliferation, and reducing apoptosis by negatively regulating TNF-α. AZGP1 is suggested to be a novel promising therapeutic target for NAFLD.展开更多
This study aimed to explore the mechanism of a novel mutation (p.Lys38Glu) in apolipoprotein H (APOH) gene causing hereditary beta2-glycoprotein I (β2GPI) deficiency and thrombosis in a proband with thrombophil...This study aimed to explore the mechanism of a novel mutation (p.Lys38Glu) in apolipoprotein H (APOH) gene causing hereditary beta2-glycoprotein I (β2GPI) deficiency and thrombosis in a proband with thrombophilia. The plasma level of β2GPI was measured by ELISA and Western blotting, and anti-β2GPI antibody by ELISA. Lupus anticoagulant (LA) was assayed using the dilute Russell viper venom time. Deficiency of the major natural anticoagulants including protein C (PC), protein S (PS), antithrombin (AT) and thrombomodulin (TM) was excluded from the proband. A mutation analysis was performed by amplification and sequencing of the APOH gene. Wild type and mutant (c.112A〉G) APOH expression plasmids were constructed and transfected into HEK293T cells. The results showed that the thrornbin generation capacity of the proband was higher than that of the other family members. Missense mutation p.Lys38Glu in APOH gene and LA coexisted in the proband. The mutation led to β2GPI deficiency and thrombosis by impairing the protein production and inhibiting the platelet aggregation. It was concluded that the recurrent thrombosis of the proband is associated with the coexistence ofp.Lys38Glu mutation in APOH gene and LA in plasma.展开更多
Objective:To investigate the levels of zinc-α-2-glycoprotein(ZAG) among Omani AIDS patients receiving combined antiretroviral therapy(cART).Methods:A total of 80 Omani AIDS patients(45 males and 33 females),average a...Objective:To investigate the levels of zinc-α-2-glycoprotein(ZAG) among Omani AIDS patients receiving combined antiretroviral therapy(cART).Methods:A total of 80 Omani AIDS patients(45 males and 33 females),average age of 36 vears.who were receiving cART at the Saltan Qaboos University Hospital(SQUH).Muscat,Oman,were tested for the levels of ZAG.In addition,SO healthy blood donors(46 males and 34 females),average age of 26 years,attending the SOUH Blood Bank,were tested in parallel as a control group.Measurement of the ZAG levels was performed using a competitive enzyme—linked immunosorbent assay and in accordance with the manufacturer's instructions.Results:The ZAG levels were found to he significantly higher among AIDS patients compared to the healthy individuals(P=0.033).A total of 56(70%) of the AIDS patients were found to have higher levels of ZAG and 16(20%) AIDS patients were found to have high ZAG levels,which are significantly(P>0.031) associated with weight loss.Conclusions:ZAG levels are high among Omani AIDS patients on cART and this necessitales the measurement of ZAG on routine basis,as it is associated with weight loss.展开更多
Antiphospholipid syndrome(APS)is typically characterized by increased levels of three classes of antiphospholipid antibodies,namely lupus anticoagulant,anti-β2-glycoprotein I(anti-β2GPI),and anticardiolipin antibodi...Antiphospholipid syndrome(APS)is typically characterized by increased levels of three classes of antiphospholipid antibodies,namely lupus anticoagulant,anti-β2-glycoprotein I(anti-β2GPI),and anticardiolipin antibodies.β2-Glycoprotein(β2GPI)is a phospholipid-binding protein composed of five domains(DI-V)and a major antigen in APS.β2GPI is expressed on the surfaces of several cell types,including endothelial cells,monocytes,trophoblast cells,and platelets.Its binding to the anti-β2GPI antibody triggers downstream signaling events and ultimately exerts a variety of cellular effects.β2GPI modulates hemostasis and the complement system,as well as playing an important role in APS-associated vascular injury.Therefore,studying β2GPI will help elucidate the pathogenesis of APS and improve the treatment of patients with this condition.This review will mainly focus on the structure and function of β2GPI,as well as its implication in the pathogenesis of APS.展开更多
Zinc-α2-glycoprotein(ZAG), encoded by the AZGP1 gene, is a major histocompatibility complex I molecule and a lipid-mobilizing factor. ZAG has been demonstrated to promote lipid metabolism and glucose utilization, and...Zinc-α2-glycoprotein(ZAG), encoded by the AZGP1 gene, is a major histocompatibility complex I molecule and a lipid-mobilizing factor. ZAG has been demonstrated to promote lipid metabolism and glucose utilization, and to regulate insulin sensitivity. Apart from adipose tissue, skeletal muscle, liver, and kidney, ZAG also occurs in brain tissue, but its distribution in brain is debatable. Only a few studies have investigated ZAG in the brain. It has been found in the brains of patients with Krabbe disease and epilepsy, and in the cerebrospinal fluid of patients with Alzheimer disease, frontotemporal lobe dementia, and amyotrophic lateral sclerosis. Both ZAG protein and AZGP1 m RNA are decreased in epilepsy patients and animal models, while overexpression of ZAG suppresses seizure and epileptic discharges in animal models of epilepsy, but knowledge of the specific mechanism of ZAG in epilepsy is limited. In this review, we summarize the known roles and molecular mechanisms of ZAG in lipid metabolism and glucose metabolism, and in the regulation of insulin sensitivity, and discuss the possible mechanisms by which it suppresses epilepsy.展开更多
AIM: To establish and compare serum proteomic of diabetic retinopathy (DR) patients in various phases and discuss pathogenesis of DR so as to find out possible serum specific molecular markers for early diagnosis of D...AIM: To establish and compare serum proteomic of diabetic retinopathy (DR) patients in various phases and discuss pathogenesis of DR so as to find out possible serum specific molecular markers for early diagnosis of DR. METHODS: Thirty-two subjects were divided into four groups: one group of eight type 2 diabetes mellitus (T2DM) patients without apparent DR (No-DR, NDR), one group of eight T2DM patients with non-proliferative diabetic retinopathy (NPDR), one group of eight T2DM patients with proliferative diabetic retinopathy(PDR) and one group of eight healthy volunteer participants. Two dimensional fluorescence difference gel electrophoresis (2D-DIGE) was applied to establish differential protein expression profiles in four groups. Matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry (MALDI-TOF-TOF MS) was applied to identify mass spectrometry of differential proteins and analyze follow-up bioinformatics. RESULTS: 2D-DIGE maps of serum protein were satisfactory obtained from NDR, NPDR, PDR and normal control groups. Twenty-six different proteins spots were screened(the volume ratio was > 1.5 based on DeCyder software analysis). Twenty-four of them were verified and two of them were not. Fifteen proteins were verified. Most of them were high-abundant proteins in serum. The four relatively low-abundant ones were beta 2-glycoprotein I (beta (2)-GPI), alpha2-HS-glycoprotein (AHSG), alpha1-acid glycoprotein (alpha(1)-AGP) and apolipoprotein A-1 (apo A-1). beta (2)-GPI expression was gradually increased in the development of DR but unrelated to the severity of DR. The volume ratio of beta (2)-GPI is 1.54, 2.43, and 2.84 in NDR, NPDR and PDR group respectively compared with normal control group. CONCLUSION: Serum proteomic analysis of 2D-DIGE combined with MALDI-TOF-TOF MS is feasible to be applied in the study of DR. 13 2-GPI probably takes part in the process of DR occurrence and development and it could be a candidate biomarker on DR diagnosis in early phase.展开更多
Systemic lupus erythematosus is a prototypic model for B-cell epitope spread in autoimmunity.Autoantibodies to numerous molecularly distinct self-antigens emerge in a sequential manner over several years,leading to di...Systemic lupus erythematosus is a prototypic model for B-cell epitope spread in autoimmunity.Autoantibodies to numerous molecularly distinct self-antigens emerge in a sequential manner over several years,leading to disease manifestations.Among the earliest autoantibodies to appear are those targeting phospholipid-binding proteins,particularlyβ2-glycoprotein Ⅰ.Notably,mice immunized with β2-glycoprotein Ⅰ and lipopolysaccharide develop a strong T cell response to β2-glycoprotein Ⅰ that is associated with autoantibody production and renal disease,similar to that seen in human SLE.Here we hypothesized that mice with murine systemic lupus erythematosus,whether induced or spontaneous,should have T cells that recognizeβ2-glycoprotein I.We evaluated the response of splenic T cells from mice with induced(C57BL/6 and C3H/HeN)and spontaneous(MRL/lpr)systemic lupus erythematosus to peptides spanning the entire sequence of humanβ2GPI.We found that mice with induced and spontaneous systemic lupus erythematosus recognize a common T cell epitope(peptide 31;LYRDTAVFECLPQHAMFG)in domain Ⅲ ofβ2-glycoprotein I.β2GPI-reactive CD4^(+)T cells from the two models differed primarily in cytokine production:T cells from mice with induced SLE expressed IFN-γ,while T cells from MRL/lpr mice expressed both IL-17 and IFN-γ,indicating that IL-17-expressing T cells are not necessary for generating aβ2GPI-reactive T cell response.These data suggest that the generation of aβ2-glycoprotein Ireactive T cell response is shared by both induced and spontaneous models of systemic lupus erythematosus and that this T cell response may mediate epitope spread to autoantibodies in both models.展开更多
AIM:To investigate the effect of leucine-rich-alpha-2-glycoprotein 1(LRG1)on epithelial-mesenchymal transition(EMT)in retinal pigment epithelium(RPE)cells,and to explore the role of NADPH oxidase 4(NOX4).METHODS:RPE c...AIM:To investigate the effect of leucine-rich-alpha-2-glycoprotein 1(LRG1)on epithelial-mesenchymal transition(EMT)in retinal pigment epithelium(RPE)cells,and to explore the role of NADPH oxidase 4(NOX4).METHODS:RPE cells(ARPE-19 cell line)were treated with transforming growth factor-β1(TGF-β1)to induce EMT.Changes of the m RNA and protein expression levels of LRG1 were tested in the TGF-β1 treated cells.The recombinant human LRG1 protein(r LRG1)and si RNA of LRG1 were used to establish accumulation of exogenous LRG1 model and the down-regulation of LRG1 model in ARPE-19 cells respectively,and to detect EMT-related markers including fibronectin,α-smooth muscle actin(α-SMA)and zonula occludens-1(ZO-1).The m RNA and protein expression level of NOX4 were measured according to the above treatments.VAS2870 was used as a NOX4 inhibitor in r LRG1-treated cells.EMT-related markers were detected to verify the effect of NOX4 in the process of EMT.RESULTS:TGF-β1 promoted the expression of LRG1 at both the m RNA and protein levels during the process of EMT which showed the up-regulation of fibronectin andα-SMA,as well as the down-regulation of ZO-1.Furthermore,the r LRG1 promoted EMT of ARPE-19 cells,which manifested high levels of fibronectin andα-SMA and low level of ZO-1,whereas knockdown of LRG1 prevented EMT by decreasing the expressions of fibronectin andα-SMA and increasing the expression of ZO-1 in ARPE-19 cells.Besides,the r LRG1 activated and LRG1 si RNA suppressed NOX4 expression.EMT was inhibited when VAS2870 was used in the r LRG1-treated cells.CONCLUSION:These results for the first time demonstrate that LRG1 promotes EMT of RPE cells by activating NOX4,which may provide a novel direction to explore the mechanisms of subretinal fibrosis.展开更多
基金Supported by the National Natural Science Foundation of China,No.81570547 and No.81770597the Development Program of China during the 13~(th) Five-year Plan Period,No.2017ZX10203202003005
文摘BACKGROUND Zinc-α2-glycoprotein 1 (AZGP1) plays important roles in metabolism-related diseases. The underlying molecular mechanisms and therapeutic effects of AZGP1 remain unknown in non-alcoholic fatty liver disease (NAFLD). AIM To explore the effects and potential mechanism of AZGP1 on NAFLD in vivo and in vitro. METHODS The expression of AZGP1 and its effects on hepatocytes were examined in NAFLD patients, CCl4-treated mice fed a high fat diet (HFD), and human LO2 cells. RESULTS AZGP1 levels were significantly decreased in liver tissues of NAFLD patients and mice. AZGP1 knockdown was found to activate inflammation;enhance steatogenesis, including promoting lipogenesis [sterol regulatory elementbinding protein (SREBP)-1c, liver X receptor (LXR), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and stearoyl CoA desaturase 1 (SCD)-1], increasing lipid transport and accumulation [fatty acid transport protein (FATP), carnitine palmitoyl transferase (CPT)-1A, and adiponectin], and reducing fatty acid β-oxidation [farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor (PPAR)-α];accelerate proliferation;and reverse apoptosis in LO2 cells. AZGP1 overexpression (OV-AZGP1) had the opposite effects. Furthermore, AZGP1 alleviated NAFLD by blocking TNF-α-mediated inflammation and intracellular lipid deposition, promoting proliferation, and inhibiting apoptosis in LO2 cells. Finally, treatment with OV-AZGP1 plasmid dramatically improved liver injury and eliminated liver fat in NAFLD mice. CONCLUSION AZGP1 attenuates NAFLD with regard to ameliorating inflammation, accelerating lipolysis, promoting proliferation, and reducing apoptosis by negatively regulating TNF-α. AZGP1 is suggested to be a novel promising therapeutic target for NAFLD.
文摘This study aimed to explore the mechanism of a novel mutation (p.Lys38Glu) in apolipoprotein H (APOH) gene causing hereditary beta2-glycoprotein I (β2GPI) deficiency and thrombosis in a proband with thrombophilia. The plasma level of β2GPI was measured by ELISA and Western blotting, and anti-β2GPI antibody by ELISA. Lupus anticoagulant (LA) was assayed using the dilute Russell viper venom time. Deficiency of the major natural anticoagulants including protein C (PC), protein S (PS), antithrombin (AT) and thrombomodulin (TM) was excluded from the proband. A mutation analysis was performed by amplification and sequencing of the APOH gene. Wild type and mutant (c.112A〉G) APOH expression plasmids were constructed and transfected into HEK293T cells. The results showed that the thrornbin generation capacity of the proband was higher than that of the other family members. Missense mutation p.Lys38Glu in APOH gene and LA coexisted in the proband. The mutation led to β2GPI deficiency and thrombosis by impairing the protein production and inhibiting the platelet aggregation. It was concluded that the recurrent thrombosis of the proband is associated with the coexistence ofp.Lys38Glu mutation in APOH gene and LA in plasma.
基金Supported by the Research Council of the Sultanate of Oman(RC/MED/MICR/11/01)the College of Medicine and Health Sciences,Sultan Qaboos University(Internal-Grant/2013).Oman
文摘Objective:To investigate the levels of zinc-α-2-glycoprotein(ZAG) among Omani AIDS patients receiving combined antiretroviral therapy(cART).Methods:A total of 80 Omani AIDS patients(45 males and 33 females),average age of 36 vears.who were receiving cART at the Saltan Qaboos University Hospital(SQUH).Muscat,Oman,were tested for the levels of ZAG.In addition,SO healthy blood donors(46 males and 34 females),average age of 26 years,attending the SOUH Blood Bank,were tested in parallel as a control group.Measurement of the ZAG levels was performed using a competitive enzyme—linked immunosorbent assay and in accordance with the manufacturer's instructions.Results:The ZAG levels were found to he significantly higher among AIDS patients compared to the healthy individuals(P=0.033).A total of 56(70%) of the AIDS patients were found to have higher levels of ZAG and 16(20%) AIDS patients were found to have high ZAG levels,which are significantly(P>0.031) associated with weight loss.Conclusions:ZAG levels are high among Omani AIDS patients on cART and this necessitales the measurement of ZAG on routine basis,as it is associated with weight loss.
基金National Natural Science Foundation of China,Grant/Award Numbers:92268107,82170476Natural Science Foundation of Beijing,China,Grant/Award Number:M21008。
文摘Antiphospholipid syndrome(APS)is typically characterized by increased levels of three classes of antiphospholipid antibodies,namely lupus anticoagulant,anti-β2-glycoprotein I(anti-β2GPI),and anticardiolipin antibodies.β2-Glycoprotein(β2GPI)is a phospholipid-binding protein composed of five domains(DI-V)and a major antigen in APS.β2GPI is expressed on the surfaces of several cell types,including endothelial cells,monocytes,trophoblast cells,and platelets.Its binding to the anti-β2GPI antibody triggers downstream signaling events and ultimately exerts a variety of cellular effects.β2GPI modulates hemostasis and the complement system,as well as playing an important role in APS-associated vascular injury.Therefore,studying β2GPI will help elucidate the pathogenesis of APS and improve the treatment of patients with this condition.This review will mainly focus on the structure and function of β2GPI,as well as its implication in the pathogenesis of APS.
基金supported by the National Natural Science Foundation of China(81771391,81401073)Chongqing Municipal Public Health Bureau,Chongqing People’s Municipal Government(20142026)the Program for Innovative Research Team of Chongqing Kuanren Hospital,China
文摘Zinc-α2-glycoprotein(ZAG), encoded by the AZGP1 gene, is a major histocompatibility complex I molecule and a lipid-mobilizing factor. ZAG has been demonstrated to promote lipid metabolism and glucose utilization, and to regulate insulin sensitivity. Apart from adipose tissue, skeletal muscle, liver, and kidney, ZAG also occurs in brain tissue, but its distribution in brain is debatable. Only a few studies have investigated ZAG in the brain. It has been found in the brains of patients with Krabbe disease and epilepsy, and in the cerebrospinal fluid of patients with Alzheimer disease, frontotemporal lobe dementia, and amyotrophic lateral sclerosis. Both ZAG protein and AZGP1 m RNA are decreased in epilepsy patients and animal models, while overexpression of ZAG suppresses seizure and epileptic discharges in animal models of epilepsy, but knowledge of the specific mechanism of ZAG in epilepsy is limited. In this review, we summarize the known roles and molecular mechanisms of ZAG in lipid metabolism and glucose metabolism, and in the regulation of insulin sensitivity, and discuss the possible mechanisms by which it suppresses epilepsy.
基金Supported by Natural Science Fund for Colleges and Universities in Anhui Province, China (No.KJ2007B208)
文摘AIM: To establish and compare serum proteomic of diabetic retinopathy (DR) patients in various phases and discuss pathogenesis of DR so as to find out possible serum specific molecular markers for early diagnosis of DR. METHODS: Thirty-two subjects were divided into four groups: one group of eight type 2 diabetes mellitus (T2DM) patients without apparent DR (No-DR, NDR), one group of eight T2DM patients with non-proliferative diabetic retinopathy (NPDR), one group of eight T2DM patients with proliferative diabetic retinopathy(PDR) and one group of eight healthy volunteer participants. Two dimensional fluorescence difference gel electrophoresis (2D-DIGE) was applied to establish differential protein expression profiles in four groups. Matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry (MALDI-TOF-TOF MS) was applied to identify mass spectrometry of differential proteins and analyze follow-up bioinformatics. RESULTS: 2D-DIGE maps of serum protein were satisfactory obtained from NDR, NPDR, PDR and normal control groups. Twenty-six different proteins spots were screened(the volume ratio was > 1.5 based on DeCyder software analysis). Twenty-four of them were verified and two of them were not. Fifteen proteins were verified. Most of them were high-abundant proteins in serum. The four relatively low-abundant ones were beta 2-glycoprotein I (beta (2)-GPI), alpha2-HS-glycoprotein (AHSG), alpha1-acid glycoprotein (alpha(1)-AGP) and apolipoprotein A-1 (apo A-1). beta (2)-GPI expression was gradually increased in the development of DR but unrelated to the severity of DR. The volume ratio of beta (2)-GPI is 1.54, 2.43, and 2.84 in NDR, NPDR and PDR group respectively compared with normal control group. CONCLUSION: Serum proteomic analysis of 2D-DIGE combined with MALDI-TOF-TOF MS is feasible to be applied in the study of DR. 13 2-GPI probably takes part in the process of DR occurrence and development and it could be a candidate biomarker on DR diagnosis in early phase.
基金funded in part by operating grants from the Canadian Institutes of Health Research(CIHR,MOP-67101 and MOP-97916,J.R.)。
文摘Systemic lupus erythematosus is a prototypic model for B-cell epitope spread in autoimmunity.Autoantibodies to numerous molecularly distinct self-antigens emerge in a sequential manner over several years,leading to disease manifestations.Among the earliest autoantibodies to appear are those targeting phospholipid-binding proteins,particularlyβ2-glycoprotein Ⅰ.Notably,mice immunized with β2-glycoprotein Ⅰ and lipopolysaccharide develop a strong T cell response to β2-glycoprotein Ⅰ that is associated with autoantibody production and renal disease,similar to that seen in human SLE.Here we hypothesized that mice with murine systemic lupus erythematosus,whether induced or spontaneous,should have T cells that recognizeβ2-glycoprotein I.We evaluated the response of splenic T cells from mice with induced(C57BL/6 and C3H/HeN)and spontaneous(MRL/lpr)systemic lupus erythematosus to peptides spanning the entire sequence of humanβ2GPI.We found that mice with induced and spontaneous systemic lupus erythematosus recognize a common T cell epitope(peptide 31;LYRDTAVFECLPQHAMFG)in domain Ⅲ ofβ2-glycoprotein I.β2GPI-reactive CD4^(+)T cells from the two models differed primarily in cytokine production:T cells from mice with induced SLE expressed IFN-γ,while T cells from MRL/lpr mice expressed both IL-17 and IFN-γ,indicating that IL-17-expressing T cells are not necessary for generating aβ2GPI-reactive T cell response.These data suggest that the generation of aβ2-glycoprotein Ireactive T cell response is shared by both induced and spontaneous models of systemic lupus erythematosus and that this T cell response may mediate epitope spread to autoantibodies in both models.
基金Supported by the National Natural Science Foundation of China(No.81670828)the Shandong Provincial Key Research and Development Program(No.2017GSF18141)+1 种基金the Innovation Project of Shandong Academy of Medical Sciences and the National Science and Technology Major Project of China(No.2017ZX09304-010)partially supported by the Taishan Scholar Youth Professional Program(No.tspd20150215,No.tsgn20161059)。
文摘AIM:To investigate the effect of leucine-rich-alpha-2-glycoprotein 1(LRG1)on epithelial-mesenchymal transition(EMT)in retinal pigment epithelium(RPE)cells,and to explore the role of NADPH oxidase 4(NOX4).METHODS:RPE cells(ARPE-19 cell line)were treated with transforming growth factor-β1(TGF-β1)to induce EMT.Changes of the m RNA and protein expression levels of LRG1 were tested in the TGF-β1 treated cells.The recombinant human LRG1 protein(r LRG1)and si RNA of LRG1 were used to establish accumulation of exogenous LRG1 model and the down-regulation of LRG1 model in ARPE-19 cells respectively,and to detect EMT-related markers including fibronectin,α-smooth muscle actin(α-SMA)and zonula occludens-1(ZO-1).The m RNA and protein expression level of NOX4 were measured according to the above treatments.VAS2870 was used as a NOX4 inhibitor in r LRG1-treated cells.EMT-related markers were detected to verify the effect of NOX4 in the process of EMT.RESULTS:TGF-β1 promoted the expression of LRG1 at both the m RNA and protein levels during the process of EMT which showed the up-regulation of fibronectin andα-SMA,as well as the down-regulation of ZO-1.Furthermore,the r LRG1 promoted EMT of ARPE-19 cells,which manifested high levels of fibronectin andα-SMA and low level of ZO-1,whereas knockdown of LRG1 prevented EMT by decreasing the expressions of fibronectin andα-SMA and increasing the expression of ZO-1 in ARPE-19 cells.Besides,the r LRG1 activated and LRG1 si RNA suppressed NOX4 expression.EMT was inhibited when VAS2870 was used in the r LRG1-treated cells.CONCLUSION:These results for the first time demonstrate that LRG1 promotes EMT of RPE cells by activating NOX4,which may provide a novel direction to explore the mechanisms of subretinal fibrosis.