angptl4 recombinant protein  (MedChemExpress)

Journal: Journal of orthopaedic research : official publication of the Orthopaedic Research Society

Article Title: Lipolysis products from triglyceride-rich lipoproteins induce stress protein ATF3 in osteoblasts.

doi: 10.1002/jor.25756

Figure Lengend Snippet: FIGURE 5 Lipolysis products induce the expression of Angptl4 in MC3T3‐E1 cells. Cells were exposed to 0−150 mg/dL TGRL mixed with 2 units/mL LPL for 3 or 6 h. Bars represent mean ± SEM, n = 4−6, ****p < 0.0001 compared to 0 TGRL + LPL (Ctrl). LPL, lipoprotein lipase; TGRL, triglyceride‐rich lipoproteins.

Article Snippet: Recombinant full length murine ANGPTL4 (4880‐AN‐050) was purchased from R&D Systems.

Techniques: Expressing

Journal: Journal of orthopaedic research : official publication of the Orthopaedic Research Society

Article Title: Lipolysis products from triglyceride-rich lipoproteins induce stress protein ATF3 in osteoblasts.

doi: 10.1002/jor.25756

Figure Lengend Snippet: FIGURE 6 Recombinant ANGPTL4 inhibits lipolysis product‐ induction of Atf3 in MC3T3‐E1 cells. Cells were exposed to 100 mg/dL TGRL mixed with 2 units/mL LPL for 6 h. In some experiments, LPL and ANGPTL4 (0.1−5 µg/mL) were mixed for 30 min before the addition of TGRL. Ctrl represents cells not exposed to TGRL/LPL/ANGPTL4. Bars represent mean ± SEM, n = 4−6. *p < 0.05, ***p < 0.001, ****p < 0.0001 compared to 0 µg/mL ANGPTL4. LPL, lipoprotein lipase; TGRL, triglyceride‐rich lipoproteins.

Article Snippet: Recombinant full length murine ANGPTL4 (4880‐AN‐050) was purchased from R&D Systems.

Techniques: Recombinant

Journal: Journal of orthopaedic research : official publication of the Orthopaedic Research Society

Article Title: Lipolysis products from triglyceride-rich lipoproteins induce stress protein ATF3 in osteoblasts.

doi: 10.1002/jor.25756

Figure Lengend Snippet: FIGURE 11 (A) Lipoprotein lipase (LPL) (or hepatic lipase) secreted by the osteoblast translocates to the plasma membrane of endothelial cells lining blood vessels, where it catalyzes the conversion of triglyceride‐rich lipoproteins (TGRL) into lipolysis products (LP) such as free fatty acids (FFA). LP translocate to the osteoblast for use as a metabolic fuel source. (B) High circulating levels of TGRL result in high levels of LP which induce an increase in ATF3 in osteoblasts (pathway 1), and induce IL6 and COX‐2, known downstream genes of ATF3; LP also induce intracellular ROS accumulation, which together result in inflammation. LP induce an increase in angiopoietin‐like 4 (ANGPTL4) (pathway 2), an inhibitor of LPL, which may act in a negative feedback loop, reducing LPL activity, reducing LP accumulation in the local environment, and protecting cells from inflammation. Note it is possible that lipases may be active on the osteoblast cell membrane itself. ATF3, activating transcription factor 3; ROS, reactive oxygen species.

Article Snippet: Recombinant full length murine ANGPTL4 (4880‐AN‐050) was purchased from R&D Systems.

Techniques: Clinical Proteomics, Membrane, Activity Assay

Journal: Experimental & molecular medicine

Article Title: ANGPTL4 stabilizes atherosclerotic plaques and modulates the phenotypic transition of vascular smooth muscle cells through KLF4 downregulation.

doi: 10.1038/s12276-023-00937-x

Figure Lengend Snippet: Fig. 1 Effects of ANGPTL4 administration on atherosclerotic progression in the atherosclerosis Apoe−/−mouse model. a Experimental scheme. Apoe−/−mice were fed a high-fat diet (HFD) with an injection of PBS or recombinant ANGPTL4 protein (2 μg per mouse, intraperitoneally twice a week) for 8 weeks. Blood, BMDMs, aortic roots, and aortas were collected for further analyses. b Representative Oil red O-stained aortas from PBS-injected and ANGPTL4-injected Apoe−/−mice fed an HFD for 8 weeks. The relative atherosclerotic plaque area was quantified. c, Lesion area measured in Oil red O-stained cross sections of the aortic roots from the PBS and ANGPTL4 groups. The plaque area was measured and quantified as the relative size of the plaque to the aortic area. Scale bar, 500 μm. d Representative images are shown for H&E-stained aortic roots from the PBS and ANGPTL4 groups. The necrotic core area, qualified by the anucleated area, was measured and quantified as the relative size of the necrotic core to the plaque or aortic root. Scale bar, 500 μm. e Representative images of atherosclerotic aortas were obtained using high-resolution optical resolution photoacoustic microscopy (OR-PAM). Blue arrows indicate atherosclerotic plaques. f Scanning electron microscope images showing the aorta surface isolated from the PBS and ANGPTL4 groups. Boxed areas on the aortic surface depict atherosclerotic plaques at higher magnification. Scale bar, 20 μm. Data were presented as the mean ± SEM. #p < 0.05, ##p < 0.01, ###p < 0.001 (by Student’s t-test).

Article Snippet: Apoe−/− mice receiving a high-fat diet were intraperitoneally injected with 2 μg of ANGPTL4 (4880-AN, R&D Systems) two times per week for 8 weeks.

Techniques: Injection, Recombinant, Staining, Microscopy, Isolation

Journal: Experimental & molecular medicine

Article Title: ANGPTL4 stabilizes atherosclerotic plaques and modulates the phenotypic transition of vascular smooth muscle cells through KLF4 downregulation.

doi: 10.1038/s12276-023-00937-x

Figure Lengend Snippet: Fig. 2 Effects of ANGPTL4 on macrophage function in atherosclerosis. a, b Proinflammatory and anti-inflammatory gene expression were analyzed by real-time PCR in BMDMs isolated from Apoe−/−mice treated with PBS or ANGPTL4. c BMDMs from the PBS and ANGPTL4 groups were analyzed using Oil red O staining. Scale bar, 200 μm. d BMDMs from the PBS and ANGPTL4 groups were treated with oxLDL-DyLight 488 for 24 h, and then oxidized LDL uptake was analyzed. Scale bar, 200 μm. e Flow cytometry analyses of single-cell aortic suspensions isolated from the PBS and ANGPTL4 groups. Inflammatory macrophages were quantified by the number of CD80+ cells among the CD45+F4/ 80+CD11b+ population. f, g The content of macrophages in aortic root sections from the two groups was determined by immunohistochemical staining with anti-CD68 antibody (f) and anti-Mac2 antibodies (g). Representative images are shown, and CD68- positive areas (f) and Mac2-positive areas (g) were measured and quantified as a percentage of the plaque area. Data were presented as the mean ± SEM. #p < 0.05, ##p < 0.01, ###p < 0.001, ####p < 0.0001 (by Student’s t-test).

Article Snippet: Apoe−/− mice receiving a high-fat diet were intraperitoneally injected with 2 μg of ANGPTL4 (4880-AN, R&D Systems) two times per week for 8 weeks.

Techniques: Gene Expression, Real-time Polymerase Chain Reaction, Isolation, Staining, Flow Cytometry, Immunohistochemical staining

Journal: Experimental & molecular medicine

Article Title: ANGPTL4 stabilizes atherosclerotic plaques and modulates the phenotypic transition of vascular smooth muscle cells through KLF4 downregulation.

doi: 10.1038/s12276-023-00937-x

Figure Lengend Snippet: Fig. 3 The expression patterns of atherogenic mediators from the aortas and plasma of Apoe−/−mice. Relative expression of genes related to contractility (a), proinflammation (b), and macrophage markers (c) in aortas isolated from the PBS and ANGPTL4 groups. Apoe−/− mice fed a high-fat diet (HFD) were injected with PBS or ANGPTL4 twice a week for 8 weeks (2 μg, i.p.). ANGPTL4 expression in aortas (d) and aortic SMCs (e, f) of Apoe−/−mice and human aortic SMCs (g). Aortic SMCs were stimulated with cholesterol (10 μg/ml) or TNFα (100 ng/ml) and oxLDL (10 μg/ml) with or without ANGPTL4. h Circulating leptin, IL-6, IL-1β, and IL-18 were quantified in the PBS and ANGPTL4 groups. Data were presented as the mean ± SEM. #p < 0.05, ##p < 0.01, ###p < 0.001, ####p < 0.0001 (by Student’s t-test or one-way ANOVA with Bonferroni’s multiple-comparisons test).

Article Snippet: Apoe−/− mice receiving a high-fat diet were intraperitoneally injected with 2 μg of ANGPTL4 (4880-AN, R&D Systems) two times per week for 8 weeks.

Techniques: Expressing, Clinical Proteomics, Isolation, Injection

Journal: Experimental & molecular medicine

Article Title: ANGPTL4 stabilizes atherosclerotic plaques and modulates the phenotypic transition of vascular smooth muscle cells through KLF4 downregulation.

doi: 10.1038/s12276-023-00937-x

Figure Lengend Snippet: Fig. 4 Effects of ANGPTL4 on the stability of atherosclerotic plaques. a–e Representative histologic analysis of the aortic root from the PBS and ANGPTL4 groups. a Representative images of Masson trichrome staining are shown. Boxed areas in the aortic root depict the fibrous cap and necrotic core at higher magnification, and the fibrous cap and necrotic core were measured as the lesion thickness. Scale bar, 100 μm. b Representative images of picrosirius red staining for collagen, and quantification of the collagen content presented as a percentage of the plaque area. Scale bar, 100 μm. Immunofluorescence staining of atherosclerotic plaques showed α-SMA and CD68 (c), SM22α (d), and SM-MHC (e) in the fibrous caps. Quantification of the fibrous cap thickness is presented in the right panels. Scale bar, 20 μm. f H&E (left panels) and SM- MHC and SM22α-stained confocal images of lesions representing preatheromatous plaques and complicated lesions of the human LAD. Scale bar, 10 μm. Data were presented as the mean ± SEM. #p < 0.05, ###p < 0.001 (by Student’s t-test). LAD left anterior descending artery.

Article Snippet: Apoe−/− mice receiving a high-fat diet were intraperitoneally injected with 2 μg of ANGPTL4 (4880-AN, R&D Systems) two times per week for 8 weeks.

Techniques: Staining

Journal: Experimental & molecular medicine

Article Title: ANGPTL4 stabilizes atherosclerotic plaques and modulates the phenotypic transition of vascular smooth muscle cells through KLF4 downregulation.

doi: 10.1038/s12276-023-00937-x

Figure Lengend Snippet: Fig. 6 Attenuation of KLF4 upregulation by ANGPTL4 in atherosclerosis. a Expression of KLF4 within the plaque of the aortic root from the two groups was determined by immunofluorescent staining. Data were the mean fluorescence intensity (MFI) of KLF4 (mean ± SEM, n = 8). Scale bar, 20 μm. b, c Aortic SMCs were isolated from atherosclerotic Apoe−/−mice treated with PBS or ANGPTL4, and the level of KLF4 was measured. The levels of KLF4 mRNA (b) and protein (c) were lower in the ANGPTL4 group than in the PBS group. d Western blotting of KLF4 expression in SMCs from Apoe−/−mice pretreated with ANGPTL4 for 24 h and then stimulated with cholesterol (10 μg/ml) for 72 h. e KLF4 promoter activity was increased in human aortic SMCs stimulated by oxLDL (10 μg/ml) or oxLDL and TNFα (100 ng/ml) for 24 h but was inhibited by ANGPTL4 (1, 5 μg/ml) treatment. f Representative images of α-SMA+KLF4+ staining in preatheromatous plaques and complicated lesions of the human LAD. Scale bar, 10 μm. Data were presented as the mean ± SEM. #p < 0.05, ##p < 0.01, ###p < 0.001 (by Student’s t-test or one-way ANOVA with Bonferroni’s multiple-comparisons test).

Article Snippet: Apoe−/− mice receiving a high-fat diet were intraperitoneally injected with 2 μg of ANGPTL4 (4880-AN, R&D Systems) two times per week for 8 weeks.

Techniques: Expressing, Staining, Isolation, Western Blot, Activity Assay

Journal: Experimental & molecular medicine

Article Title: ANGPTL4 stabilizes atherosclerotic plaques and modulates the phenotypic transition of vascular smooth muscle cells through KLF4 downregulation.

doi: 10.1038/s12276-023-00937-x

Figure Lengend Snippet: Fig. 7 ANGPTL4 modulates SMC phenotypic changes through KLF4 induction by NOX1. a Aortic SMCs pretreated with ANGPTL4 were stimulated with cholesterol (10 μg/ml) or oxLDL (10 μg/ml) and TNFα (100 ng/ml), and the levels of Nox1 and KLF4 were measured. b Aortas were isolated from atherosclerotic Apoe−/−mice treated with PBS or ANGPTL4, and the levels of Nox1 and KLF4 were measured. c Representative images and quantification of dihydroethidium (DHE) fluorescence in aortic root sections. The aortic root sections were incubated with 5 μM DHE for 10 min in the dark. The data presented are the MFI of DHE (mean ± SEM, n = 9). Scale bar, 100 μm. d Representative images of CM-H2DCFDA staining. Aortic SMCs from atherosclerotic Apoe−/−mice were pretreated with ANGPTL4 and TNFα and exposed to 13 μM CM-H2DCFDA. Quantification of ROS levels by MFI. Scale bar, 100 μm. e, f Human aortic SMCs were stimulated with oxLDL (10 μg/ml) and TNFα (100 ng/ml) with or without ML171, a NOX1 inhibitor (0.5 μg/ml, 5 μg/ml), and were stained with KLF4 (e) and α- SMA and CD68 (f). Scale bar, 100 μm. g Proposed mechanism of action for ANGPTL4 administration in atherosclerosis and plaque stabilization. Data were presented as the mean ± SEM. #p < 0.05, ##p < 0.01, ###p < 0.001, ####p < 0.0001 (by Student’s t-test or one-way ANOVA with Bonferroni’s multiple-comparisons test).

Article Snippet: Apoe−/− mice receiving a high-fat diet were intraperitoneally injected with 2 μg of ANGPTL4 (4880-AN, R&D Systems) two times per week for 8 weeks.

Techniques: Isolation, Incubation, Staining

Journal: Experimental & molecular medicine

Article Title: ANGPTL4 stabilizes atherosclerotic plaques and modulates the phenotypic transition of vascular smooth muscle cells through KLF4 downregulation.

doi: 10.1038/s12276-023-00937-x

Figure Lengend Snippet: Fig. 8 Circulating levels of ANGPTL4 in patients with cardiovascular disease. a Distribution of plasma levels of ANGPTL4 measured in all patients (n = 207). b Plasma levels of ANGPTL4 in the low ANGPTL4 (n = 103) and high ANGPTL4 (n = 104) groups. c Kaplan‒Meier curve illustrating the vascular event incidence of patients during the follow-up period after surgery based on plasma ANGPTL4 levels above (red) and below (blue) the median value. Data were presented as the mean ± SEM. ####p < 0.0001 (by Student’s t-test).

Article Snippet: Apoe−/− mice receiving a high-fat diet were intraperitoneally injected with 2 μg of ANGPTL4 (4880-AN, R&D Systems) two times per week for 8 weeks.

Techniques: Clinical Proteomics