BACKGROUND The prevalence of metabolic dysfunction-associated fatty liver disease(MAFLD)is rapidly increasing,currently affecting approximately 25%of the global population.Liver fibrosis represents a crucial stage in ...BACKGROUND The prevalence of metabolic dysfunction-associated fatty liver disease(MAFLD)is rapidly increasing,currently affecting approximately 25%of the global population.Liver fibrosis represents a crucial stage in the development of MAFLD,with advanced liver fibrosis elevating the risks of cirrhosis and hepatocellular carcinoma.Simple serum markers are less effective in diagnosing liver fibrosis compared to more complex markers.However,imaging techniques like transient elastography face limitations in clinical application due to equipment and technical constraints.Consequently,it is imperative to identify a straightforward yet effective method for assessing MAFLD-associated liver fibrosis.AIM To investigate the predictive value of angiopoietin-like protein 8(ANGPTL8)in MAFLD and its progression.METHODS We analyzed 160 patients who underwent abdominal ultrasonography in the Endocrinology Department,Xiaogan Central Hospital affiliated to Wuhan University of Science and Technology,during September 2021-July 2022.Using abdominal ultrasonography and MAFLD diagnostic criteria,among the 160 patients,80 patients(50%)were diagnosed with MAFLD.The MAFLD group was divided into the liver fibrosis group(n=23)and non-liver fibrosis group(n=57)by using a cut-off fibrosis-4 index≥1.45.Logistical regression was used to analyze the risk of MAFLD and the risk factors for its progression.Receiver operating characteristic curves were used to evaluate the predictive value of serum ANGPTL8 in MAFLD and its progression.RESULTS Compared with non-MAFLD patients,MAFLD patients had higher serum ANGPTL8 and triglyceride-glucose(TyG)index(both P<0.05).Serum ANGPTL8(r=0.576,P<0.001)and TyG index(r=0.473,P<0.001)were positively correlated with MAFLD.Serum ANGPTL8 was a risk factor for MAFLD[odds ratio(OR):1.123,95%confidence interval(CI):1.066-1.184,P<0.001).Serum ANGPTL8 and ANGPTL8+TyG index predicted MAFLD[area under the curve(AUC):0.832 and 0.886,respectively;both P<0.05].Compared with MAFLD patients without fibrosis,those with fibrosis had higher serum ANGPTL8 and TyG index(both P<0.05),and both parameters were positively correlated with MAFLD-associated fibrosis.Elevated serum ANGPTL8(OR:1.093,95%CI:1.044-1.144,P<0.001)and TyG index(OR:2.383,95%CI:1.199-4.736,P<0.013)were risk factors for MAFLD-associated fibrosis.Serum ANGPTL8 and ANGPTL8+TyG index predicted MAFLD-associated fibrosis(AUC:0.812 and 0.835,respectively;both P<0.05).CONCLUSION The serum levels of ANGPTL8 are elevated and positively correlated with MAFLD.They can serve as predictors for the risk of MAFLD and liver fibrosis,with the ANGPTL8+TyG index potentially exhibiting even higher predictive value.展开更多
AIM：To confirm the role of angiopoietin-like protein 8（Angptl 8） in proliferative diabetic retinopathy（PDR）.METHODS：The sera and aqueous humor of 10 PDR patients and 10 non-diabetic retinopathy（NDR） patients（...AIM：To confirm the role of angiopoietin-like protein 8（Angptl 8） in proliferative diabetic retinopathy（PDR）.METHODS：The sera and aqueous humor of 10 PDR patients and 10 non-diabetic retinopathy（NDR） patients（idiopathic macular hole patients） were collected and the expression of Angptl 8 was detected by enzyme linked immune-sorbent assay（ELISA）.Experimental diabetes mice model was induced with streptozotocin.The expression of glycosylated hemoglobin and Angptl 8 in sera was detected.Recombinant Angptl 8 was re-infused into wild type（WT） diabetic mice and spatial frequency threshold and contrast sensitivity were measured.In vitro retinal pigment epithelium（RPE） were stimulated by recombinant Angptl 8 for 24 h.MMT assay were used to detect cell proliferation.At the same time,q RT-PCR and Western blot was used to measure the expression of proliferation-related factors in PRE cells.RESULTS：The expression of Angptl 8 was markedly increased in the sera and aqueous humor of PDR patients（F=99.02,P〈0.0001 in sera;t=10.42,P〈0.0001 in aqueous）.After successfully establishing the diabetic mice model,we found that glycosylated hemoglobin and Angptl 8 expression levels were increased.Re-infusion of recombinant Angptl 8 into WT diabetic mice could further decrease spatial frequency threshold and contrast sensitivity（P〈0.01）.In vitro,RPE cells stimulated by recombinant Angptl 8could increase the relative absorbance of MMT assay（1.486±0.042 vs 1.000±0.104,P〈0.05） and proliferating cell nuclear antigen（PCNA） expression（0.55±0.01 vs 0.29±0.03,P〈0.05）.The proliferative effect of Angptl 8 is mainly mediated by increasing the expression of proliferation-activating factors cyclin A1（4.973±0.205 vs 2.720±0.197,P〈0.05）,cyclin F（5.690±0.219 vs 4.297±0.292,P〈0.05） and E2 F2（2.297±0.102 vs 1.750±0.146,P〈0.05）,and reducing the expression of proliferation-inhibiting factors cdkn1（2.370±0.074 vs 3.317±0.135,P〈0.05） and cdkn2（4.793±0.065 vs 5.387±0.149,P〈0.05）.CONCLUSION：The expression of Angptl 8 is increased in PDR,and the increased Angptl 8 can promote proliferation and increase proliferation-related factors.展开更多
BACKGROUND Intestinal barrier breakdown,a frequent complication of intestinal ischemiareperfusion(I/R)including dysfunction and the structure changes of the intestine,is characterized by a loss of tight junction and e...BACKGROUND Intestinal barrier breakdown,a frequent complication of intestinal ischemiareperfusion(I/R)including dysfunction and the structure changes of the intestine,is characterized by a loss of tight junction and enhanced permeability of the intestinal barrier and increased mortality.To develop effective and novel therapeutics is important for the improvement of outcome of patients with intestinal barrier deterioration.Recombinant human angiopoietin-like protein 4(rhANGPTL4)is reported to protect the blood-brain barrier when administered exogenously,and endogenous ANGPTL4 deficiency deteriorates radiationinduced intestinal injury.AIM To identify whether rhANGPTL4 may protect intestinal barrier breakdown induced by I/R.METHODS Intestinal I/R injury was elicited through clamping the superior mesenteric artery for 60 min followed by 240 min reperfusion.Intestinal epithelial(Caco-2)cells and human umbilical vein endothelial cells were challenged by hypoxia/reoxygenation to mimic I/R in vitro.RESULTS Indicators including fluorescein isothiocyanate-conjugated dextran(4 kilodaltons;FD-4)clearance,ratio of phosphorylated myosin light chain/total myosin light chain,myosin light chain kinase and loss of zonula occludens-1,claudin-2 and VE-cadherin were significantly increased after intestinal I/R or cell hypoxia/reoxygenation.rhANGPTL4 treatment significantly reversed these indicators,which were associated with inhibiting the inflammatory and oxidative cascade,excessive activation of cellular autophagy and apoptosis and improvement of survival rate.Similar results were observed in vitro when cells were challenged by hypoxia/reoxygenation,whereas rhANGPTL4 reversed the indicators close to normal level in Caco-2 cells and human umbilical vein endothelial cells significantly.CONCLUSION rhANGPTL4 can function as a protective agent against intestinal injury induced by intestinal I/R and improve survival via maintenance of intestinal barrier structure and functions.展开更多
Three members of the angiopoietin-like(ANGPTL) protein family-ANGPTL3, ANGPTL4 and ANGPTL8-are important regulators of plasma lipoproteins. They inhibit the enzyme lipoprotein lipase, which plays a key role in the int...Three members of the angiopoietin-like(ANGPTL) protein family-ANGPTL3, ANGPTL4 and ANGPTL8-are important regulators of plasma lipoproteins. They inhibit the enzyme lipoprotein lipase, which plays a key role in the intravascular lipolysis of triglycerides present in some lipoprotein classes. This review focuses on the role of ANGPTL3 as emerged from the study of genetic variants of Angptl3 gene in mice and humans. Both loss of function genetic variants and inactivation of Angptl3 gene in mice are associated with a marked reduction of plasma levels of triglyceride and cholesterol and an increased activity of lipoprotein lipase and endothelial lipase. In humans with ANGPTL3 deficiency, caused by homozygous loss of function(LOF) variants of Angptl3 gene, the levels of all plasma lipoproteins are greatly reduced. This plasma lipid disorder referred to as familial combined hypolipidemia(FHBL2) does not appear to be associated with distinct pathological manifestations. Heterozygous carriers of LOF variants have reduced plasma levels of total cholesterol and triglycerides and are at lower risk of developing atherosclerotic cardiovascular disease, as compared to non-carriers. These observations have paved the way to the development of strategies to reduce the plasma level of atherogenic lipoproteins in man by the inactivation of ANGPTL3, using either a specific monoclonal antibody or anti-sense oligonucleotides.展开更多
AIM:To quantitatively detect aqueous levels of angiopoietin-like(ANGPTL)3,ANGPTL4,and ANGPTL6 and investigate their correlation with optical coherence tomography angiography(OCTA)findings in patients with diabetic mac...AIM:To quantitatively detect aqueous levels of angiopoietin-like(ANGPTL)3,ANGPTL4,and ANGPTL6 and investigate their correlation with optical coherence tomography angiography(OCTA)findings in patients with diabetic macular edema(DME).METHODS:This cross-sectional study included 23 patients(27 eyes)with type 2 diabetes and 16 control subjects(20 eyes).All patients underwent OCTA imaging and ultra-wide field fundus photography.Diabetic patients were categorized into two groups according to the presence or absence of diabetic retinopathy(DME group,14 patients,16 eyes);and non-diabetic retinopathy(NDR)group,9 patients,11 eyes,respectively.Aqueous levels of ANGPTL3,ANGPTL4,and ANGPTL6 were assessed using suspension array technology,and foveal-centered 3×3 mm2 OCTA scans were automatically graded to determine the central,inner,and full vessel density(CVD,IVD,FVD);central,inner,and full perfusion density(CPD,IPD,FPD),foveal avascular zone(FAZ)area,FAZ perimeter,and FAZ circularity index(FAZ-CI)on superficial capillary plexuses.Additionally,central subfield thickness(CST),cube volume(CV),and cube average thickness(CAT)were measured in a model of macular cube 512×128.RESULTS:Aqueous ANGPTL3 levels were not significantly different among the three groups(P>0.05).ANGPTL4 levels were significantly higher in the DME group than the control and NDR groups(P<0.0001 and P<0.001),while ANGPTL6 levels were significantly higher in the DME group than the control group(P<0.05).In the whole cohort,the aqueous ANGPTL3 levels correlated negatively with the IVD,FVD,IPD,and FPD,and positively with the CV and CAT.The aqueous ANGPTL4 levels correlated negatively with the CVD,IVD,FVD,CPD,IPD,and FPD,and positively with the FAZ perimeter,CST,CV,and CAT.The aqueous ANGPTL6 levels correlated negatively with the IVD,FVD,IPD,FPD,FAZCI and positively with CST,CV,CAT.CONCLUSION:ANGPTL4 and ANGPTL6 may be associated with vascular leakage in DME and may represent good targets for DME therapy.In addition,OCTA metrics may be useful for evaluating macular ischemia in DME.展开更多
Pregnancy toxemia is a metabolic disorder of lipid and glucose. Recent investigations have found that angiopoietin-like protein 3 （ANGPTL3） can contribute to disorder of carbohydrate and lipid metabolism. The presen...Pregnancy toxemia is a metabolic disorder of lipid and glucose. Recent investigations have found that angiopoietin-like protein 3 （ANGPTL3） can contribute to disorder of carbohydrate and lipid metabolism. The present study was conducted to investigate the change of ANGPTL3 expression during pregnancy toxemia, We firstly cloned the full-length cDNA of ANGPTL3 in Liuyang Black goats, revealing that goat ANGPTL3 had the typical structure of the angiopoietin-like family, and its mRNA was exclusively expressed in liver. Pregnancy toxemia of pregnant goat does with twins during late gestation was induced by being fasted for 72 h, and then they were recovered after 5 d ofrefeeding. Hepatic ANGPTL3 gene expression was significantly down-regulated concomitantly with decreased serum glucose concentration, elevated serum β-hydroxybutyrate and free fatty acid levels in pregnant toxemic goats, and these changes were reversed after refeeding. These results suggest ANGPTL3 may play a certain role in the development of pregnancy toxemia in goats.展开更多
Objective： The aim of the study was to construct the eukaryotic expression vector of human angiopoietin-like protein 4 （ANGPTL4） and observe the effect of ANGPTL4 overexpression on the growth of esophageal carcinom...Objective： The aim of the study was to construct the eukaryotic expression vector of human angiopoietin-like protein 4 （ANGPTL4） and observe the effect of ANGPTL4 overexpression on the growth of esophageal carcinoma EC9706 cells. Methods： Total RNA was extracted from normal hepatic tissue, and ANGPTL4 cDNA was amplified by RT-PCR. The PCR product was doubly digested by Xbal and Sail, and then recombined into eukaryotic expression vector. Then, plRES-GFP-ANGPTL4 was obtained by G418 selection, then plRES-GFP-ANGPTL4 and plRES-GFP were transfected into EC9706 cells with lipidosome-packaged method. Meanwhile, the transfected cells were selected by G418, and then stable transfected cell lines were obtained. ANGPTL4 mRNA levels, the celt cycles and growth curves of EC9706 cells in experiment group （transfected with plRES-GFP-ANGPTL4）, empty vector group （transfected with plRES-GFP） and blank control group （EC9706 cells without transfection） were detected with RT-PCR, flow cytometry and MTT methods, respectively. Results： Eukaryotic ANGPTL4 expression vector plRES-GFP-ANGPTL4 was successfully constructed. The ANGPTL4 mRNA level （0.21 ± 0.03） in experiment group was significantly higher than that of the empty vector group （0.04 ± 0.008） and the blank control group （0.05 ± 0.007）, with significant differences （P 〈 0.01）. The proportion of cells in S phase in experiment group was significantly different with those of the other two groups （P 〈 0.05）. The cell growth of EC9706 cells in experiment group was slower than those of the other two groups. From the third day, the differences began to be significant. Conclusion： ANGPTL4 overexpression in esophageal carcinoma EC9706 cells could inhibit the growth of EC9706 cells.展开更多
Recovery of functional beta cell mass offers a biological cure for type 1 diabetes. However, beta cell mass is difficult to regain once lost since the proliferation rate of beta cells after youth is very low. Angiopoi...Recovery of functional beta cell mass offers a biological cure for type 1 diabetes. However, beta cell mass is difficult to regain once lost since the proliferation rate of beta cells after youth is very low. Angiopoietin like-protein 8 (ANGPTL8), a peptide that has a role in the regulation of lipoprotein lipase activity, was reported to increase beta cell proliferation in mice in 2013. Subsequent studies of human ANGPTL8 for short term (3 to 8 days) in non-diabetic mice showed little or no increase in beta cell proliferation. Here, we examined the effect of ANGPTL8 on glucose homeostasis in models that have not been examined previously. We expressed mouse ANGPTL8 using adenovirus in 2 mouse models of diabetes (streptozotocin and Non-Obese Diabetic (NOD) mice) over 2 weeks. Also, we tested ANGPTL8 in NOD mice deficient in leukocyte 12-lipoxygenase (12LO), an enzyme that contributes to insulitis and loss of beta cell function in NOD, in an effort to determine whether 12LO deficiency alters the response to ANGPTL8. Adenovirus-mediated expression of ANGPTL8 lowered blood glucose levels in streptozotocin treated mice without an increase in beta cell proliferation or serum insulin concentration. While ANGPTL8 did not reverse hyperglycemia in overtly hyperglycemic NOD mice or alter glucose homeostasis of non-diabetic NOD mice, ANGPTL8 reduced blood glucose levels in 12LOKO NOD mice. However, the lower glucose levels in 12LOKO NOD were not associated with higher serum insulin levels or beta cell proliferation. In summary, while mouse ANGPTL8 does not increase beta cell proliferation in NOD mice or streptozotocin treated mice in agreement with studies in non-diabetic mice, it lowers blood glucose levels in multiple low-dose streptozotocin induced diabetes and 12LO deficiency indicating that host factors influence the impact of ANGPTL8 on glucose homeostasis.展开更多
Background：A recent study reported a positive association between elevated serum levels of angiopoietin-like protein 2 （ANGPTL2） and the development of type 2 diabetes in a general population.However,the relationsh...Background：A recent study reported a positive association between elevated serum levels of angiopoietin-like protein 2 （ANGPTL2） and the development of type 2 diabetes in a general population.However,the relationship of serum ANGPTL2 levels with the risk of developing gestational diabetes mellitus （GDM） has not been reported to date.The aim of this study was to investigate the change of maternal serum ANGPTL2 concentrations in the first trimester of pregnancy and to determine whether ANGPTL2 is a biomarker for subsequent GDM development.Methods：We conducted a prospective,nested case-control study in a pregnancy cohort.First-trimester ANGPTL2 levels were measured using a high-resolution assay in 89 women who subsequently developed GDM and in a random sample of 177 women who remained euglycemic throughout the pregnancy.Median ANGPTL2 levels were compared using Mann-Whitney U-test.Logistic regression was used to compute unadjusted and multivariable-adjusted odds ratios for developing GDM among ANGPTL2 quartiles.Results：The serum levels of ANGPTL2 was higher in women with GDM than that in women without GDM （3.06 [2.59,3.65] ng/ml vs.2.46 [2.05,2.96] ng/ml,P =0.003）.Fasting blood glucose was higher in women with GDM than that in women without GDM （5.0 ± 0.9 mmol/L vs.4.4 ± 0.6 mmol/L,P 〈 0.001）.Glucose challenge test showed that the blood glucose was higher in women with GDM than that in women without GDM （9.1 ± 3.5 mmol/L vs.6.2 ± 1.2 mmol/L,P 〈 0.001）.A multivariate model adjusted for baseline characteristics,medical complications,and gestational characteristics revealed that the risk of developing GDM among women in Q4 compared with Q1 was 2.90-fold more likely to develop GDM later in pregnancy.Conclusions：At 1 1-13 weeks in pregnancies that develop GDM,the serum concentration of ANGPTL2 is increased,and it can be combined with maternal factors to provide effective early screening for GDM.展开更多
Recent advances in hematopoietic stem cells(HSCs)expansion by growth factors including angiopoietin-like proteins(Angptls)have opened up the possibility to use HSCs in regenerative medicine.However,the unavailability ...Recent advances in hematopoietic stem cells(HSCs)expansion by growth factors including angiopoietin-like proteins(Angptls)have opened up the possibility to use HSCs in regenerative medicine.However,the unavailability of true in vitro HSCs expansion by these growth factors has limited the understanding of the cellular and molecular mechanism of HSCs expansion.Here,we report the functional role of mouse Angptls 1,2,3,4,6 and 7 and growth factors SCF,TPO,IGF-2 and FGF-1 on purified mouse bone-marrow(BM)Lineage-Sca-1+(Lin-Sca-1+)HSCs.The recombinant retroviral transduced-CHO-S cells that secrete Angptls in serum-free medium were used alone or in combination with growth factors(SCF,TPO,IGF-2 and FGF-1).None of the Angptls stimu-lated HSC proliferation,enhanced or inhibited HSCs colony formation,but they did support the survival of HSCs.By contrast,any of the six Angptls together with saturating levels of growth factors dramatically stimulated a 3-to 4.5-fold net expansion of HSCs compared to stimulation with a combination of those growth factors alone.These findings lead to an understanding of the basic function of Angptls on signaling pathways for the survival as well as expansion of HSCs in the bone marrow niche.展开更多
Podocyte injury is an important cause of proteinuria.Angiopoietin-like protein 4(Angptl4)is a secreted glycoprotein and has a role in proteinuria.However,the exact role of Angptl4 in podocyte injury and its upstream r...Podocyte injury is an important cause of proteinuria.Angiopoietin-like protein 4(Angptl4)is a secreted glycoprotein and has a role in proteinuria.However,the exact role of Angptl4 in podocyte injury and its upstream regulators has not been clarified.In this study,we used lipopolysaccharide(LPS)-induced mice and cultured podocytes as podocyte injury models.Our results indicated that LPS increased the expression of podocyte Angptl4 in vivo and in vitro.Furthermore,we showed that Angptl4 overexpression deteriorated LPS-induced podocyte injury by inducing podocyte cytoskeleton rearrangement,reducing the expression of synaptopodin while Angptl4 knockdown alleviated LPS-induced podocyte injury.In addition,we found that inhibitors and siRNA targeting TLR4/MyD88/NF-κB signaling inhibited the upregulation of Angptl4 in LPS-induced podocytes.Moreover,inhibitors and siRNA targeting calcineurin/NFAT signaling also relieved LPS-induced Angptl4 expression and podocyte injury in vivo and in vitro.Taken together,our study has elucidated that both of the TLR4/MyD88/NF-κB and calcineurin/NFAT signaling mediate the upregulation of Angptl4 in LPS-induced podocytes,which has important implications for further understanding the molecular mechanism of LPS-induced podocyte injury.展开更多
基金Supported by Youth Talents Project of Joint Fund of Hubei Health Commission,No.WJ2019H170and Xiaogan Natural Science Project,No.XGKJ2020010033。
文摘BACKGROUND The prevalence of metabolic dysfunction-associated fatty liver disease(MAFLD)is rapidly increasing,currently affecting approximately 25%of the global population.Liver fibrosis represents a crucial stage in the development of MAFLD,with advanced liver fibrosis elevating the risks of cirrhosis and hepatocellular carcinoma.Simple serum markers are less effective in diagnosing liver fibrosis compared to more complex markers.However,imaging techniques like transient elastography face limitations in clinical application due to equipment and technical constraints.Consequently,it is imperative to identify a straightforward yet effective method for assessing MAFLD-associated liver fibrosis.AIM To investigate the predictive value of angiopoietin-like protein 8(ANGPTL8)in MAFLD and its progression.METHODS We analyzed 160 patients who underwent abdominal ultrasonography in the Endocrinology Department,Xiaogan Central Hospital affiliated to Wuhan University of Science and Technology,during September 2021-July 2022.Using abdominal ultrasonography and MAFLD diagnostic criteria,among the 160 patients,80 patients(50%)were diagnosed with MAFLD.The MAFLD group was divided into the liver fibrosis group(n=23)and non-liver fibrosis group(n=57)by using a cut-off fibrosis-4 index≥1.45.Logistical regression was used to analyze the risk of MAFLD and the risk factors for its progression.Receiver operating characteristic curves were used to evaluate the predictive value of serum ANGPTL8 in MAFLD and its progression.RESULTS Compared with non-MAFLD patients,MAFLD patients had higher serum ANGPTL8 and triglyceride-glucose(TyG)index(both P<0.05).Serum ANGPTL8(r=0.576,P<0.001)and TyG index(r=0.473,P<0.001)were positively correlated with MAFLD.Serum ANGPTL8 was a risk factor for MAFLD[odds ratio(OR):1.123,95%confidence interval(CI):1.066-1.184,P<0.001).Serum ANGPTL8 and ANGPTL8+TyG index predicted MAFLD[area under the curve(AUC):0.832 and 0.886,respectively;both P<0.05].Compared with MAFLD patients without fibrosis,those with fibrosis had higher serum ANGPTL8 and TyG index(both P<0.05),and both parameters were positively correlated with MAFLD-associated fibrosis.Elevated serum ANGPTL8(OR:1.093,95%CI:1.044-1.144,P<0.001)and TyG index(OR:2.383,95%CI:1.199-4.736,P<0.013)were risk factors for MAFLD-associated fibrosis.Serum ANGPTL8 and ANGPTL8+TyG index predicted MAFLD-associated fibrosis(AUC:0.812 and 0.835,respectively;both P<0.05).CONCLUSION The serum levels of ANGPTL8 are elevated and positively correlated with MAFLD.They can serve as predictors for the risk of MAFLD and liver fibrosis,with the ANGPTL8+TyG index potentially exhibiting even higher predictive value.
文摘AIM：To confirm the role of angiopoietin-like protein 8（Angptl 8） in proliferative diabetic retinopathy（PDR）.METHODS：The sera and aqueous humor of 10 PDR patients and 10 non-diabetic retinopathy（NDR） patients（idiopathic macular hole patients） were collected and the expression of Angptl 8 was detected by enzyme linked immune-sorbent assay（ELISA）.Experimental diabetes mice model was induced with streptozotocin.The expression of glycosylated hemoglobin and Angptl 8 in sera was detected.Recombinant Angptl 8 was re-infused into wild type（WT） diabetic mice and spatial frequency threshold and contrast sensitivity were measured.In vitro retinal pigment epithelium（RPE） were stimulated by recombinant Angptl 8 for 24 h.MMT assay were used to detect cell proliferation.At the same time,q RT-PCR and Western blot was used to measure the expression of proliferation-related factors in PRE cells.RESULTS：The expression of Angptl 8 was markedly increased in the sera and aqueous humor of PDR patients（F=99.02,P〈0.0001 in sera;t=10.42,P〈0.0001 in aqueous）.After successfully establishing the diabetic mice model,we found that glycosylated hemoglobin and Angptl 8 expression levels were increased.Re-infusion of recombinant Angptl 8 into WT diabetic mice could further decrease spatial frequency threshold and contrast sensitivity（P〈0.01）.In vitro,RPE cells stimulated by recombinant Angptl 8could increase the relative absorbance of MMT assay（1.486±0.042 vs 1.000±0.104,P〈0.05） and proliferating cell nuclear antigen（PCNA） expression（0.55±0.01 vs 0.29±0.03,P〈0.05）.The proliferative effect of Angptl 8 is mainly mediated by increasing the expression of proliferation-activating factors cyclin A1（4.973±0.205 vs 2.720±0.197,P〈0.05）,cyclin F（5.690±0.219 vs 4.297±0.292,P〈0.05） and E2 F2（2.297±0.102 vs 1.750±0.146,P〈0.05）,and reducing the expression of proliferation-inhibiting factors cdkn1（2.370±0.074 vs 3.317±0.135,P〈0.05） and cdkn2（4.793±0.065 vs 5.387±0.149,P〈0.05）.CONCLUSION：The expression of Angptl 8 is increased in PDR,and the increased Angptl 8 can promote proliferation and increase proliferation-related factors.
基金the National Natural Science Foundation of China,No.81600446the Science and Technology of Traditional Chinese Medicine Foundation in Qingdao,No.2021-zyyz03the Science and technology development of Medicine and health Foundation in Shandong Province,China,No.202004010508.
文摘BACKGROUND Intestinal barrier breakdown,a frequent complication of intestinal ischemiareperfusion(I/R)including dysfunction and the structure changes of the intestine,is characterized by a loss of tight junction and enhanced permeability of the intestinal barrier and increased mortality.To develop effective and novel therapeutics is important for the improvement of outcome of patients with intestinal barrier deterioration.Recombinant human angiopoietin-like protein 4(rhANGPTL4)is reported to protect the blood-brain barrier when administered exogenously,and endogenous ANGPTL4 deficiency deteriorates radiationinduced intestinal injury.AIM To identify whether rhANGPTL4 may protect intestinal barrier breakdown induced by I/R.METHODS Intestinal I/R injury was elicited through clamping the superior mesenteric artery for 60 min followed by 240 min reperfusion.Intestinal epithelial(Caco-2)cells and human umbilical vein endothelial cells were challenged by hypoxia/reoxygenation to mimic I/R in vitro.RESULTS Indicators including fluorescein isothiocyanate-conjugated dextran(4 kilodaltons;FD-4)clearance,ratio of phosphorylated myosin light chain/total myosin light chain,myosin light chain kinase and loss of zonula occludens-1,claudin-2 and VE-cadherin were significantly increased after intestinal I/R or cell hypoxia/reoxygenation.rhANGPTL4 treatment significantly reversed these indicators,which were associated with inhibiting the inflammatory and oxidative cascade,excessive activation of cellular autophagy and apoptosis and improvement of survival rate.Similar results were observed in vitro when cells were challenged by hypoxia/reoxygenation,whereas rhANGPTL4 reversed the indicators close to normal level in Caco-2 cells and human umbilical vein endothelial cells significantly.CONCLUSION rhANGPTL4 can function as a protective agent against intestinal injury induced by intestinal I/R and improve survival via maintenance of intestinal barrier structure and functions.
文摘Three members of the angiopoietin-like(ANGPTL) protein family-ANGPTL3, ANGPTL4 and ANGPTL8-are important regulators of plasma lipoproteins. They inhibit the enzyme lipoprotein lipase, which plays a key role in the intravascular lipolysis of triglycerides present in some lipoprotein classes. This review focuses on the role of ANGPTL3 as emerged from the study of genetic variants of Angptl3 gene in mice and humans. Both loss of function genetic variants and inactivation of Angptl3 gene in mice are associated with a marked reduction of plasma levels of triglyceride and cholesterol and an increased activity of lipoprotein lipase and endothelial lipase. In humans with ANGPTL3 deficiency, caused by homozygous loss of function(LOF) variants of Angptl3 gene, the levels of all plasma lipoproteins are greatly reduced. This plasma lipid disorder referred to as familial combined hypolipidemia(FHBL2) does not appear to be associated with distinct pathological manifestations. Heterozygous carriers of LOF variants have reduced plasma levels of total cholesterol and triglycerides and are at lower risk of developing atherosclerotic cardiovascular disease, as compared to non-carriers. These observations have paved the way to the development of strategies to reduce the plasma level of atherogenic lipoproteins in man by the inactivation of ANGPTL3, using either a specific monoclonal antibody or anti-sense oligonucleotides.
基金National Natural Science Foundation of China(No.81741058)Key Research and Development Program of Shaanxi Province(No.2021SF-155)First Affiliated Hospital of Xi’an Jiaotong University(No.2019QN-05).
文摘AIM:To quantitatively detect aqueous levels of angiopoietin-like(ANGPTL)3,ANGPTL4,and ANGPTL6 and investigate their correlation with optical coherence tomography angiography(OCTA)findings in patients with diabetic macular edema(DME).METHODS:This cross-sectional study included 23 patients(27 eyes)with type 2 diabetes and 16 control subjects(20 eyes).All patients underwent OCTA imaging and ultra-wide field fundus photography.Diabetic patients were categorized into two groups according to the presence or absence of diabetic retinopathy(DME group,14 patients,16 eyes);and non-diabetic retinopathy(NDR)group,9 patients,11 eyes,respectively.Aqueous levels of ANGPTL3,ANGPTL4,and ANGPTL6 were assessed using suspension array technology,and foveal-centered 3×3 mm2 OCTA scans were automatically graded to determine the central,inner,and full vessel density(CVD,IVD,FVD);central,inner,and full perfusion density(CPD,IPD,FPD),foveal avascular zone(FAZ)area,FAZ perimeter,and FAZ circularity index(FAZ-CI)on superficial capillary plexuses.Additionally,central subfield thickness(CST),cube volume(CV),and cube average thickness(CAT)were measured in a model of macular cube 512×128.RESULTS:Aqueous ANGPTL3 levels were not significantly different among the three groups(P>0.05).ANGPTL4 levels were significantly higher in the DME group than the control and NDR groups(P<0.0001 and P<0.001),while ANGPTL6 levels were significantly higher in the DME group than the control group(P<0.05).In the whole cohort,the aqueous ANGPTL3 levels correlated negatively with the IVD,FVD,IPD,and FPD,and positively with the CV and CAT.The aqueous ANGPTL4 levels correlated negatively with the CVD,IVD,FVD,CPD,IPD,and FPD,and positively with the FAZ perimeter,CST,CV,and CAT.The aqueous ANGPTL6 levels correlated negatively with the IVD,FVD,IPD,FPD,FAZCI and positively with CST,CV,CAT.CONCLUSION:ANGPTL4 and ANGPTL6 may be associated with vascular leakage in DME and may represent good targets for DME therapy.In addition,OCTA metrics may be useful for evaluating macular ischemia in DME.
基金the National Natural Science Foundation of China (31072167)the Key Project of Hunan Provincial Science & Technology Department, China(2009FJ1005)Innovation Project of Hunan Provincial Education Department (CX2009B153), China
文摘Pregnancy toxemia is a metabolic disorder of lipid and glucose. Recent investigations have found that angiopoietin-like protein 3 （ANGPTL3） can contribute to disorder of carbohydrate and lipid metabolism. The present study was conducted to investigate the change of ANGPTL3 expression during pregnancy toxemia, We firstly cloned the full-length cDNA of ANGPTL3 in Liuyang Black goats, revealing that goat ANGPTL3 had the typical structure of the angiopoietin-like family, and its mRNA was exclusively expressed in liver. Pregnancy toxemia of pregnant goat does with twins during late gestation was induced by being fasted for 72 h, and then they were recovered after 5 d ofrefeeding. Hepatic ANGPTL3 gene expression was significantly down-regulated concomitantly with decreased serum glucose concentration, elevated serum β-hydroxybutyrate and free fatty acid levels in pregnant toxemic goats, and these changes were reversed after refeeding. These results suggest ANGPTL3 may play a certain role in the development of pregnancy toxemia in goats.
文摘Objective： The aim of the study was to construct the eukaryotic expression vector of human angiopoietin-like protein 4 （ANGPTL4） and observe the effect of ANGPTL4 overexpression on the growth of esophageal carcinoma EC9706 cells. Methods： Total RNA was extracted from normal hepatic tissue, and ANGPTL4 cDNA was amplified by RT-PCR. The PCR product was doubly digested by Xbal and Sail, and then recombined into eukaryotic expression vector. Then, plRES-GFP-ANGPTL4 was obtained by G418 selection, then plRES-GFP-ANGPTL4 and plRES-GFP were transfected into EC9706 cells with lipidosome-packaged method. Meanwhile, the transfected cells were selected by G418, and then stable transfected cell lines were obtained. ANGPTL4 mRNA levels, the celt cycles and growth curves of EC9706 cells in experiment group （transfected with plRES-GFP-ANGPTL4）, empty vector group （transfected with plRES-GFP） and blank control group （EC9706 cells without transfection） were detected with RT-PCR, flow cytometry and MTT methods, respectively. Results： Eukaryotic ANGPTL4 expression vector plRES-GFP-ANGPTL4 was successfully constructed. The ANGPTL4 mRNA level （0.21 ± 0.03） in experiment group was significantly higher than that of the empty vector group （0.04 ± 0.008） and the blank control group （0.05 ± 0.007）, with significant differences （P 〈 0.01）. The proportion of cells in S phase in experiment group was significantly different with those of the other two groups （P 〈 0.05）. The cell growth of EC9706 cells in experiment group was slower than those of the other two groups. From the third day, the differences began to be significant. Conclusion： ANGPTL4 overexpression in esophageal carcinoma EC9706 cells could inhibit the growth of EC9706 cells.
文摘Recovery of functional beta cell mass offers a biological cure for type 1 diabetes. However, beta cell mass is difficult to regain once lost since the proliferation rate of beta cells after youth is very low. Angiopoietin like-protein 8 (ANGPTL8), a peptide that has a role in the regulation of lipoprotein lipase activity, was reported to increase beta cell proliferation in mice in 2013. Subsequent studies of human ANGPTL8 for short term (3 to 8 days) in non-diabetic mice showed little or no increase in beta cell proliferation. Here, we examined the effect of ANGPTL8 on glucose homeostasis in models that have not been examined previously. We expressed mouse ANGPTL8 using adenovirus in 2 mouse models of diabetes (streptozotocin and Non-Obese Diabetic (NOD) mice) over 2 weeks. Also, we tested ANGPTL8 in NOD mice deficient in leukocyte 12-lipoxygenase (12LO), an enzyme that contributes to insulitis and loss of beta cell function in NOD, in an effort to determine whether 12LO deficiency alters the response to ANGPTL8. Adenovirus-mediated expression of ANGPTL8 lowered blood glucose levels in streptozotocin treated mice without an increase in beta cell proliferation or serum insulin concentration. While ANGPTL8 did not reverse hyperglycemia in overtly hyperglycemic NOD mice or alter glucose homeostasis of non-diabetic NOD mice, ANGPTL8 reduced blood glucose levels in 12LOKO NOD mice. However, the lower glucose levels in 12LOKO NOD were not associated with higher serum insulin levels or beta cell proliferation. In summary, while mouse ANGPTL8 does not increase beta cell proliferation in NOD mice or streptozotocin treated mice in agreement with studies in non-diabetic mice, it lowers blood glucose levels in multiple low-dose streptozotocin induced diabetes and 12LO deficiency indicating that host factors influence the impact of ANGPTL8 on glucose homeostasis.
基金This study was supported by the grant of the National Natural Science Foundation of China （No. 81471427）.
文摘Background：A recent study reported a positive association between elevated serum levels of angiopoietin-like protein 2 （ANGPTL2） and the development of type 2 diabetes in a general population.However,the relationship of serum ANGPTL2 levels with the risk of developing gestational diabetes mellitus （GDM） has not been reported to date.The aim of this study was to investigate the change of maternal serum ANGPTL2 concentrations in the first trimester of pregnancy and to determine whether ANGPTL2 is a biomarker for subsequent GDM development.Methods：We conducted a prospective,nested case-control study in a pregnancy cohort.First-trimester ANGPTL2 levels were measured using a high-resolution assay in 89 women who subsequently developed GDM and in a random sample of 177 women who remained euglycemic throughout the pregnancy.Median ANGPTL2 levels were compared using Mann-Whitney U-test.Logistic regression was used to compute unadjusted and multivariable-adjusted odds ratios for developing GDM among ANGPTL2 quartiles.Results：The serum levels of ANGPTL2 was higher in women with GDM than that in women without GDM （3.06 [2.59,3.65] ng/ml vs.2.46 [2.05,2.96] ng/ml,P =0.003）.Fasting blood glucose was higher in women with GDM than that in women without GDM （5.0 ± 0.9 mmol/L vs.4.4 ± 0.6 mmol/L,P 〈 0.001）.Glucose challenge test showed that the blood glucose was higher in women with GDM than that in women without GDM （9.1 ± 3.5 mmol/L vs.6.2 ± 1.2 mmol/L,P 〈 0.001）.A multivariate model adjusted for baseline characteristics,medical complications,and gestational characteristics revealed that the risk of developing GDM among women in Q4 compared with Q1 was 2.90-fold more likely to develop GDM later in pregnancy.Conclusions：At 1 1-13 weeks in pregnancies that develop GDM,the serum concentration of ANGPTL2 is increased,and it can be combined with maternal factors to provide effective early screening for GDM.
基金supported by Technology Development Program for Agriculture and Forestry No.610002-3,Ministry for Food,Agriculture,Forestry and Fisheries,Republic of Korea。
文摘Recent advances in hematopoietic stem cells(HSCs)expansion by growth factors including angiopoietin-like proteins(Angptls)have opened up the possibility to use HSCs in regenerative medicine.However,the unavailability of true in vitro HSCs expansion by these growth factors has limited the understanding of the cellular and molecular mechanism of HSCs expansion.Here,we report the functional role of mouse Angptls 1,2,3,4,6 and 7 and growth factors SCF,TPO,IGF-2 and FGF-1 on purified mouse bone-marrow(BM)Lineage-Sca-1+(Lin-Sca-1+)HSCs.The recombinant retroviral transduced-CHO-S cells that secrete Angptls in serum-free medium were used alone or in combination with growth factors(SCF,TPO,IGF-2 and FGF-1).None of the Angptls stimu-lated HSC proliferation,enhanced or inhibited HSCs colony formation,but they did support the survival of HSCs.By contrast,any of the six Angptls together with saturating levels of growth factors dramatically stimulated a 3-to 4.5-fold net expansion of HSCs compared to stimulation with a combination of those growth factors alone.These findings lead to an understanding of the basic function of Angptls on signaling pathways for the survival as well as expansion of HSCs in the bone marrow niche.
基金This study was supported by the National Natural Science Foundation of China(No.81400716)the Zhejiang Provincial Natural Science Foundation of China(No.LY20H050007,LY19H050005)Medical Health Science and Technology Project of Zhejiang Provincial Health Commission(No.2020383770).
文摘Podocyte injury is an important cause of proteinuria.Angiopoietin-like protein 4(Angptl4)is a secreted glycoprotein and has a role in proteinuria.However,the exact role of Angptl4 in podocyte injury and its upstream regulators has not been clarified.In this study,we used lipopolysaccharide(LPS)-induced mice and cultured podocytes as podocyte injury models.Our results indicated that LPS increased the expression of podocyte Angptl4 in vivo and in vitro.Furthermore,we showed that Angptl4 overexpression deteriorated LPS-induced podocyte injury by inducing podocyte cytoskeleton rearrangement,reducing the expression of synaptopodin while Angptl4 knockdown alleviated LPS-induced podocyte injury.In addition,we found that inhibitors and siRNA targeting TLR4/MyD88/NF-κB signaling inhibited the upregulation of Angptl4 in LPS-induced podocytes.Moreover,inhibitors and siRNA targeting calcineurin/NFAT signaling also relieved LPS-induced Angptl4 expression and podocyte injury in vivo and in vitro.Taken together,our study has elucidated that both of the TLR4/MyD88/NF-κB and calcineurin/NFAT signaling mediate the upregulation of Angptl4 in LPS-induced podocytes,which has important implications for further understanding the molecular mechanism of LPS-induced podocyte injury.
