Research progress on role of angiopoietin-like 4 in tumor progression / 中国生物制品学杂志

@#Angiopoietin-like 4(ANGPTL4)is one of the angiopoietin family members and plays a regulatory role in lipid metabolism,glucose homeostasis,inflammatory signal transduction,angiogenesis and vascular permeability.Inflammatory reaction in tumor microenvironment regulates tumor progression,and tumor angiogenesis plays a vital role in tumor growth and metastasis,so ANGPTL4 is closely related to tumor occurrence and development.Many studies have shown that ANGPTL4 plays an important regulatory role in tumor growth,anoikis resistance,tumor angiogenesis and tumor metastasis.This paper reviews the role of ANGPTL4 in tumor progression.

Danlou Tablet Improves Chronic Intermittent Hypoxia-Induced Dyslipidemia and Arteriosclerosis by HIF-1α-Angptl4 mRNA Signaling Pathway / 中国结合医学杂志

OBJECTIVE@#To detect whether Danlou Tablet (DLT) regulates the hypoxia-induced factor (HIF)-1α-angiopoietin-like 4 (Angptl4) mRNA signaling pathway and explore the role of DLT in treating chronic intermittent hypoxia (CIH)-induced dyslipidemia and arteriosclerosis.@*METHODS@#The mature adipocytes were obtained from 3T3-L1 cell culturation and allocated into 8 groups including control groups (Groups 1 and 5, 0.1 mL of cell culture grade water); DLT groups (Groups 2 and 6, 0.1 mL of 1,000 µg/mL DLT submicron powder solution); dimethyloxalylglycine (DMOG) groups (Groups 3 and 7, DMOG and 0.1 mL of cell culture grade water); DMOG plus DLT groups (Groups 4 and 8, DMOG and 0.1 mL of 1,000 µg/mL DLT submicron powder solution). Groups 1-4 used mature adipocytes and groups 5-8 used HIF-1 α-siRNA lentivirus-transfected mature adipocytes. After 24-h treatment, real-time polymerase chain reaction and Western blot were employed to determine the mRNA and protein expression levels of HIF-1 α and Angptl4. In animal experiments, the CIH model in ApoE-/- mice was established. Sixteen mice were complete randomly divided into 4 groups including sham group, CIH model group [intermittent hypoxia and normal saline (2 mL/time) gavage once a day]; Angptl4 Ab group [intermittent hypoxia and Angptl4 antibody (30 mg/kg) intraperitoneally injected every week]; DLT group [intermittent hypoxia and DLT (250 mg/kg) once a day], 4 mice in each group. After 4-week treatment, enzyme linked immunosorbent assay was used to detect the expression levels of serum total cholesterol (TC) and triglyceride (TG). Hematoxylin-eosin and CD68 staining were used to observe the morphological properties of arterial plaques.@*RESULTS@#Angptl4 expression was dependent on HIF-1 α, with a reduction in mRNA expression and no response in protein level to DMOG or DLT treatment in relation to siHIF-1 α -transfected cells. DLT inhibited HIF-1 α and Angptl4 mRNA expression (P<0.05 or P<0.01) and reduced HIF-1 α and Angptl4 protein expressions with DMOG in mature adipocytes (all P<0.01), as the effect on HIF-1 α protein also existed in the presence of siHIF-1 α (P<0.01). ApoE-/- mice treated with CIH had increased TG and TC levels (all P<0.01) and atherosclerotic plaque. Angptl4 antibody and DLT both reduce TG and TC levels (all P<0.01), as well as reducing atherosclerotic plaque areas, narrowing arterial wall thickness and alleviating atherosclerotic lesion symptoms to some extent.@*CONCLUSION@#DLT had positive effects in improving dyslipidemia and arteriosclerosis by inhibiting Angptl4 protein level through HIF-1 α-Angptl4 mRNA signaling pathway.

Influence of angiogenin-like protein 4 on pulmonary fibrosis / 中国医师杂志

Objective To investigate the important role of angiogenin-like protein 4 (Angptl4) in pulmonary fibrosis and to provide a new therapeutic targets for pulmonary fibrosis.Methods We established the pulmonary fibrosis animal models in rat by tracheal instillation of bleomycin.Then,we detected the expression of Angptl4 through real-time polymerase chain reaction (RT-PCR) and Western Blot.Rat lung fibroblast (RLF) was transfected into Angptl4-shRNA plasmid.Then we detected the changed collagen expression in RLF cells after transfection through RT-PCR and Western blot.Results The expression of Angptl4 was up-regulated in the bleomycin-induced rat pulmonary fibrosis model.The expression of both collagen Ⅰ and collagen Ⅳ in RLF cells transfected with Angptl4-shRNA plasmids were down-regulated compared with control after TGF-β treatment.Conclusions Inhibiting the expression of Angptl4 can reduce the expression of collagen fibers in lung tissue,then delaying the progression of pulmonary fibrosis.

The effects of ANGPTL4 gene on the growth of different HCC cell lines / 肿瘤

Objective: To observe the effects of angiopoietin-like 4 (ANGPTL4) gene on the growth of different hepatocellular carcinoma (HCC) cell lines. Methods: The expression of ANGPTL4 was tested by reverse transcriptase-polymerase chain reaction and Western blotting in 9 HCC cell lines and immortal liver cells. Huh-7 cells and MHCC-LM3 cells with low ANGPTL4 expression and MHCC-97L cells with moderate ANGPTL4 expression were transfected with fused ANGPTL4-GFP and empty pEGFP-N1 plasmids via Lipofetamine 2000, respectively. GFP-positive cells were screened with G418 and sorted by flow cytometry (FCM) to establish stable cell lines with over-expression of ANGPTL4, Cell array was prepared and Ki-67 fluorescent immunocytochemical techniques were used to detect in vitro proliferation of the three HCC cell lines. Xenografted tumor formation in nude mice was used to observe the effect of ANGPTL4 on the growth of the three HCC cells in vivo. Results: ANGPTL4 mRNA had low expression in Huh-7 and MHCC-LM3 cell lines, moderate expression in MHCC-97L cells, and high expression in Hep3B cells. The results of cell array showed that cell proliferation rate was lower in Huh-7 cells (P = 0.000 74), but higher in MHCC-LM3 (P = 0.073 08) and MHCC-97L (P = 0.011 52) cells with over-expression of ANGPTL4 compared with the cells transfected with empty plasmid. Over-expression of ANGPTL4 significantly inhibited xenografted tumor formation of Huh-7 cells (P = 0.001 10), but markedly promoted the xenografted tumor formation of MHCC-LM3 (P=0.057 50) and MHCC-97L (P = 0.018 91) cells in nude mice. Conclusion: ANGPTL4 plays different roles in the growth of different HCC cell lines, but the effects of ANGPTL4 on the growth of the same cell line was consistent in vitro and in vivo.

Gene transfer of human ANGPTL4 mediated by recombinant retroviral vector inhibits the growth of liver cancer / 中国普通外科杂志

Objective To construct recombinant retroviral vector containing human hepatocellular carcinoma-related gene ANGPTL4 ( angiopoietin-like 4) cDNA and to evaluate antitumor effect of recombinant retroviral vector-mediated human ANGPTL4 gene transfer. Methods ANGPTL4 cDNA was cloned in vitro from human liver cell lines HL-7702 and subcloned into plasmid vector pMSCV and sequenced. High-tiler recombinant retrovirus pMSCV-ANGPTLA and blank retrovirus pMSCV packaged under mediation of lipofectamine infected HepG2 cells in vitro, respectively. Flow cytometry and fluorescence microscopy detected expression of GFP (green fluorescence protein) in HepG2 cells. The expression of ANGPTL4 mRNA in HepG2 cells was determined. Results Recombinant retroviral vector pMSCV-ANGPTL4 was constructed successfully. Titer of recombinant retrovirus pMSCV-ANGPTL4 packaged is 1. 4 ? 106 infective viral grains /ml. Titer of blank retrovirus pMSCV packaged was 1. 5 ? 106 infective viral grains /ml. Positive cell rate of HepG2-ANGPTL4 cells group expressing GFP was 68.45% , and average intensity of fluorescence of HepG2-ANGPTL4 cells group was 31.67 -fold as that of HepG2 cells group. Positive cell rate of HepG2-pMSCV cells group expressing GFP was 77.72%, and average intensity of fluorescence of HepG2-pMSCV cells group was 64. 87 -fold as that of HepG2 cells group. The expression of ANGPTL4 mRNA in HepG2-ANGPTL4 cells group was higher than that in HepG2-pMSCV cells group (154%) and HepG2 cells group( 161%). The proliferation rate of HepG2-ANGPTL4 cells group in vitro was lower than HepG2-pMSCV cells group and HepG2 cells group (P