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1.
J Cachexia Sarcopenia Muscle ; 14(2): 978-991, 2023 04.
Article in English | MEDLINE | ID: mdl-36696895

ABSTRACT

BACKGROUND: Skeletal muscle atrophy is a common condition without a pharmacologic therapy. AGGF1 encodes an angiogenic factor that regulates cell differentiation, proliferation, migration, apoptosis, autophagy and endoplasmic reticulum stress, promotes vasculogenesis and angiogenesis and successfully treats cardiovascular diseases. Here, we report the important role of AGGF1 in the pathogenesis of skeletal muscle atrophy and attenuation of muscle atrophy by AGGF1. METHODS: In vivo studies were carried out in impaired leg muscles from patients with lumbar disc herniation, two mouse models for skeletal muscle atrophy (denervation and cancer cachexia) and heterozygous Aggf1+/- mice. Mouse muscle atrophy phenotypes were characterized by body weight and myotube cross-sectional areas (CSA) using H&E staining and immunostaining for dystrophin. Molecular mechanistic studies include co-immunoprecipitation (Co-IP), western blotting, quantitative real-time PCR analysis and immunostaining analysis. RESULTS: Heterozygous Aggf1+/- mice showed exacerbated phenotypes of reduced muscle mass, myotube CSA, MyHC (myosin heavy chain) and α-actin, increased inflammation (macrophage infiltration), apoptosis and fibrosis after denervation and cachexia. Intramuscular and intraperitoneal injection of recombinant AGGF1 protein attenuates atrophy phenotypes in mice with denervation (gastrocnemius weight 81.3 ± 5.7 mg vs. 67.3 ± 5.1 mg for AGGF1 vs. buffer; P < 0.05) and cachexia (133.7 ± 4.7 vs. 124.3 ± 3.2; P < 0.05). AGGF1 expression undergoes remodelling and is up-regulated in gastrocnemius and soleus muscles from atrophy mice and impaired leg muscles from patients with lumbar disc herniation by 50-60% (P < 0.01). Mechanistically, AGGF1 interacts with TWEAK (tumour necrosis factor-like weak inducer of apoptosis), which reduces interaction between TWEAK and its receptor Fn14 (fibroblast growth factor-inducing protein 14). This leads to inhibition of Fn14-induced NF-kappa B (NF-κB) p65 phosphorylation, which reduces expression of muscle-specific E3 ubiquitin ligase MuRF1 (muscle RING finger 1), resulting in increased MyHC and α-actin and partial reversal of atrophy phenotypes. Autophagy is reduced in Aggf1+/- mice due to inhibition of JNK (c-Jun N-terminal kinase) activation in denervated and cachectic muscles, and AGGF1 treatment enhances autophagy in two atrophy models by activating JNK. In impaired leg muscles of patients with lumbar disc herniation, MuRF1 is up-regulated and MyHC and α-actin are down-regulated; these effects are reversed by AGGF1 by 50% (P < 0.01). CONCLUSIONS: These results indicate that AGGF1 is a novel regulator for the pathogenesis of skeletal muscle atrophy and attenuates skeletal muscle atrophy by promoting autophagy and inhibiting MuRF1 expression through a molecular signalling pathway of AGGF1-TWEAK/Fn14-NF-κB. More importantly, the results indicate that AGGF1 protein therapy may be a novel approach to treat patients with skeletal muscle atrophy.


Subject(s)
Intervertebral Disc Displacement , NF-kappa B , Mice , Animals , NF-kappa B/metabolism , Angiogenesis Inducing Agents/metabolism , Cachexia/pathology , Actins , Intervertebral Disc Displacement/complications , Intervertebral Disc Displacement/metabolism , Intervertebral Disc Displacement/pathology , Muscular Atrophy/pathology , Muscle, Skeletal/pathology , Tumor Necrosis Factor-alpha , Angiogenic Proteins/metabolism
2.
Biochim Biophys Acta Mol Basis Dis ; 1868(9): 166429, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35533905

ABSTRACT

Our earlier studies identified MOG1 as a Nav1.5-binding protein that promotes Nav1.5 intracellular trafficking to plasma membranes. Genetic studies have identified MOG1 variants responsible for cardiac arrhythmias. However, the physiological functions of MOG1 in vivo remain incompletely characterized. In this study, we generated Mog1 knockout (Mog1-/-) mice. Mog1-/- mice did not develop spontaneous arrhythmias at the baseline, but exhibited a prolongation of QRS duration. Mog1-/- mice treated with isoproterenol (ISO), but not with flecainide, exhibited an increased risk of arrhythmias and even sudden death. Mog1-/- mice had normal cardiac morphology, however, LV systolic dysfunction was identified and associated with an increase in ventricular fibrosis. Whole-cell patch-clamping and Western blotting analysis clearly demonstrated the normal cardiac expression and function of Nav1.5 in Mog1-/- mice. Further RNA-seq and iTRAQ analysis identified critical pathways and genes, including extracellular matrix (Mmp2), gap junction (Gja1), and mitochondrial components that were dysregulated in Mog1-/- mice. RT-qPCR, Western blotting, and immunofluorescence assays revealed reduced cardiac expression of Gja1 in Mog1-/- mice. Dye transfer assays confirmed impairment of gap-junction function; Cx43 gap-junction enhancer ZP123 decreased arrhythmia inducibility in ISO-treated Mog1-/- mice. Transmission electron microscopy analysis revealed abnormal sarcomere ultrastructure and altered mitochondrial morphology in Mog1-/- mice. Mitochondrial dynamics was found to be disturbed, and associated with a trend toward increased mitochondrial fusion in Mog1-/- mice. Meanwhile, the level of ATP supply was increased in the hearts of Mog1-/- mice. These results indicate that MOG1 plays an important role in cardiac electrophysiology and cardiac contractile function.


Subject(s)
Connexin 43 , NAV1.5 Voltage-Gated Sodium Channel , ran GTP-Binding Protein , Animals , Arrhythmias, Cardiac/chemically induced , Arrhythmias, Cardiac/genetics , Connexin 43/genetics , Connexin 43/metabolism , Fibrosis , Isoproterenol/adverse effects , Mice , Mice, Knockout , NAV1.5 Voltage-Gated Sodium Channel/genetics , NAV1.5 Voltage-Gated Sodium Channel/metabolism , ran GTP-Binding Protein/genetics
3.
J Biol Chem ; 298(4): 101759, 2022 04.
Article in English | MEDLINE | ID: mdl-35202649

ABSTRACT

Angiogenic factor AGGF1 (AngioGenic factor with G-patch and FHA (Forkhead-Associated) domain 1) blocks neointimal formation (formation of a new or thickened layer of arterial intima) after vascular injury by regulating phenotypic switching of vascular smooth muscle cells (VSMCs). However, the AGGF1 receptor on VSMCs and the underlying molecular mechanisms of its action are unknown. In this study, we used functional analysis of serial AGGF1 deletions to reveal the critical AGGF1 domain involved in VSMC phenotypic switching. This domain was required for VSMC phenotypic switching, proliferation, cell cycle regulation, and migration, as well as the regulation of cell cycle inhibitors cyclin D, p27, and p21. This domain also contains an RDDAPAS motif via which AGGF1 interacts with integrin α7 (ITGA7), but not α8. In addition, we show that AGGF1 enhanced the expression of contractile markers MYH11, α-SMA, and SM22 and inhibited MEK1/2, ERK1/2, and ELK phosphorylation in VSMCs, and that these effects were inhibited by knockdown of ITGA7, but not by knockdown of ITGA8. In vivo, deletion of the VSMC phenotypic switching domain in mice with vascular injury inhibited the functions of AGGF1 in upregulating α-SMA and SM22, inhibiting MEK1/2, ERK1/2, and ELK phosphorylation, in VSMC proliferation, and in blocking neointimal formation. Finally, we show the inhibitory effect of AGGF1 on neointimal formation was blocked by lentivirus-delivered shRNA targeting ITGA7. Our data demonstrate that AGGF1 interacts with its receptor integrin α7 on VSMCs, and this interaction is required for AGGF1 signaling in VSMCs and for attenuation of neointimal formation after vascular injury.


Subject(s)
Muscle, Smooth, Vascular , Vascular System Injuries , Angiogenic Proteins/genetics , Angiogenic Proteins/metabolism , Animals , Antigens, CD/metabolism , Cell Movement , Cell Proliferation , Cells, Cultured , Integrin alpha Chains/metabolism , Mice , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Neointima/genetics , Neointima/metabolism , Vascular System Injuries/metabolism
4.
Cardiovasc Res ; 118(1): 196-211, 2022 01 07.
Article in English | MEDLINE | ID: mdl-33483741

ABSTRACT

AIMS: The aim of this study was to identify the molecular mechanism for hyperglycaemia-induced metabolic memory in endothelial cells (ECs), and to show its critical importance to development of cardiovascular dysfunction in diabetes. METHODS AND RESULTS: Hyperglycaemia induces increased nuclear factor-κB (NF-κB) signalling, up-regulation of miR-27a-3p, down-regulation of nuclear factor erythroid-2 related factor 2 (NRF2) expression, increased transforming growth factor-ß (TGF-ß) signalling, down-regulation of miR-29, and induction of endothelial-to-mesenchymal transition (EndMT), all of which are memorized by ECs and not erased when switched to a low glucose condition, thereby causing perivascular fibrosis and cardiac dysfunction. Similar metabolic memory effects are found for production of nitric oxide (NO), generation of reactive oxygen species (ROS), and the mitochondrial oxygen consumption rate in two different types of ECs. The observed metabolic memory effects in ECs are blocked by NRF2 activator tert-butylhydroquinone and a miR-27a-3p inhibitor. In vivo, the NRF2 activator and miR-27a-3p inhibitor block cardiac perivascular fibrosis and restore cardiovascular function by decreasing NF-κB signalling, down-regulating miR-27a-3p, up-regulating NRF2 expression, reducing TGF-ß signalling, and inhibiting EndMT during insulin treatment of diabetes in streptozotocin-induced diabetic mice, whereas insulin alone does not improve cardiac function. CONCLUSIONS: Our data indicate that disruption of hyperglycaemia-induced EC metabolic memory is required for restoring cardiac function during treatment of diabetes, and identify a novel molecular signalling pathway of NF-κB/miR-27a-3p/NRF2/ROS/TGF-ß/EndMT involved in metabolic memory.


Subject(s)
Blood Glucose/metabolism , Diabetic Cardiomyopathies/metabolism , Endothelial Cells/metabolism , Energy Metabolism , Epithelial-Mesenchymal Transition , Animals , Cells, Cultured , Diabetic Cardiomyopathies/drug therapy , Diabetic Cardiomyopathies/pathology , Diabetic Cardiomyopathies/physiopathology , Disease Models, Animal , Endothelial Cells/drug effects , Endothelial Cells/pathology , Energy Metabolism/drug effects , Epithelial-Mesenchymal Transition/drug effects , Fibrosis , Humans , Hydroquinones/pharmacology , Male , Mice, Inbred BALB C , MicroRNAs/genetics , MicroRNAs/metabolism , NF-E2-Related Factor 2/agonists , NF-E2-Related Factor 2/metabolism , NF-kappa B/metabolism , Reactive Oxygen Species/metabolism , Signal Transduction , Transforming Growth Factor beta/metabolism
5.
Acta Physiol (Oxf) ; 231(3): e13567, 2021 03.
Article in English | MEDLINE | ID: mdl-33032360

ABSTRACT

AIMS: MOG1 is a small protein that can bind to small GTPase RAN and regulate transport of RNA and proteins between the cytoplasm and nucleus. However, the in vivo physiological role of mog1 in the heart needs to be fully defined. METHODS: Mog1 knockout zebrafish was generated by TALEN. Echocardiography, histological analysis, and electrocardiograms were used to examine cardiac structure and function. RNA sequencing and real-time RT-PCR were used to elucidate the molecular mechanism and to analyse the gene expression. Isoproterenol was used to induce cardiac hypertrophy. Whole-mount in situ hybridization was used to observe cardiac morphogenesis. RESULTS: Mog1 knockout zebrafish developed cardiac hypertrophy and heart failure (enlarged pericardium, increased nppa and nppb expression and ventricular wall thickness, and reduced ejection fraction), which was aggravated by isoproterenol. RNAseq and KEGG pathway analyses revealed the effect of mog1 knockout on the pathways of cardiac hypertrophy, dilatation and contraction. Mechanistic studies revealed that mog1 knockout decreased expression of tbx5, which reduced expression of cryab and hspb2, resulting in cardiac hypertrophy and heart failure. Overexpression of cryab, hspb2 and tbx5 rescued the cardiac oedema phenotype of mog1 KO zebrafish. Telemetry electrocardiogram monitoring showed QRS and QTc prolongation and a reduced heart rate in mog1 knockout zebrafish, which was associated with reduced scn1b expression. Moreover, mog1 knockout resulted in abnormal cardiac looping during embryogenesis because of the reduced expression of nkx2.5, gata4 and hand2. CONCLUSION: Our data identified an important molecular determinant for cardiac hypertrophy and heart failure, and rhythm maintenance of the heart.


Subject(s)
Heart Failure , Zebrafish , Animals , Cardiomegaly/genetics , Heart , Heart Failure/genetics , Signal Transduction
6.
Cardiovasc Res ; 116(5): 956-969, 2020 04 01.
Article in English | MEDLINE | ID: mdl-31297506

ABSTRACT

AIMS: Cardiac fibrosis is a major cause of heart failure (HF), and mediated by the differentiation of cardiac fibroblasts into myofibroblasts. However, limited tools are available to block cardiac fibrosis. ADAMTS16 is a member of the ADAMTS superfamily of extracellular protease enzymes involved in extracellular matrix (ECM) degradation and remodelling. In this study, we aimed to establish ADAMTS16 as a key regulator of cardiac fibrosis. METHODS AND RESULTS: Western blot and qRT-PCR analyses demonstrated that ADAMTS16 was significantly up-regulated in mice with transverse aortic constriction (TAC) associated with left ventricular hypertrophy and HF, which was correlated with increased expression of Mmp2, Mmp9, Col1a1, and Col3a1. Overexpression of ADAMTS16 accelerated the AngII-induced activation of cardiac fibroblasts into myofibroblasts. Protein structural analysis and co-immunoprecipitation revealed that ADAMTS16 interacted with the latency-associated peptide (LAP)-transforming growth factor (TGF)-ß via a RRFR motif. Overexpression of ADAMTS16 induced the activation of TGF-ß in cardiac fibroblasts; however, the effects were blocked by a mutation of the RRFR motif to IIFI, knockdown of Adamts16 expression, or a TGF-ß-neutralizing antibody (ΝAb). The RRFR tetrapeptide, but not control IIFI peptide, blocked the interaction between ADAMTS16 and LAP-TGF-ß, and accelerated the activation of TGF-ß in cardiac fibroblasts. In TAC mice, the RRFR tetrapeptide aggravated cardiac fibrosis and hypertrophy by up-regulation of ECM proteins, activation of TGF-ß, and increased SMAD2/SMAD3 signalling, however, the effects were blocked by TGF-ß-NAb. CONCLUSION: ADAMTS16 promotes cardiac fibrosis, cardiac hypertrophy, and HF by facilitating cardiac fibroblasts activation via interacting with and activating LAP-TGF-ß signalling. The RRFR motif of ADAMTS16 disrupts the interaction between ADAMTS16 and LAP-TGF-ß, activates TGF-ß, and aggravated cardiac fibrosis and hypertrophy. This study identifies a novel regulator of TGF-ß signalling and cardiac fibrosis, and provides a new target for the development of therapeutic treatment of cardiac fibrosis and HF.


Subject(s)
ADAMTS Proteins/metabolism , Cardiomegaly/enzymology , Myocardium/enzymology , Myofibroblasts/enzymology , Peptides/metabolism , Protein Precursors/metabolism , Transforming Growth Factor beta/metabolism , Ventricular Remodeling , ADAMTS Proteins/genetics , Amino Acid Motifs , Animals , Cardiomegaly/genetics , Cardiomegaly/pathology , Cardiomegaly/physiopathology , Disease Models, Animal , Fibrosis , HeLa Cells , Humans , Male , Mice, Inbred C57BL , Myocardium/pathology , Myofibroblasts/pathology , Peptides/genetics , Protein Interaction Domains and Motifs , Protein Precursors/genetics , Signal Transduction , Smad2 Protein/metabolism , Smad3 Protein/metabolism , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta1/genetics , Transforming Growth Factor beta1/metabolism , Up-Regulation
7.
Diabetes ; 68(8): 1635-1648, 2019 08.
Article in English | MEDLINE | ID: mdl-31092480

ABSTRACT

Hyperglycemia-triggered vascular abnormalities are the most serious complications of diabetes mellitus (DM). The major cause of vascular dysfunction in DM is endothelial injury and dysfunction associated with the reduced number and dysfunction of endothelial progenitor cells (EPCs). A major challenge is to identify key regulators of EPCs to restore DM-associated vascular dysfunction. We show that EPCs from heterozygous knockout Aggf1+/- mice presented with impairment of proliferation, migration, angiogenesis, and transendothelial migration as in hyperglycemic mice fed a high-fat diet (HFD) or db/db mice. The number of EPCs from Aggf1+/- mice was significantly reduced. Ex vivo, AGGF1 protein can fully reverse all damaging effects of hyperglycemia on EPCs. In vivo, transplantation of AGGF1-primed EPCs successfully restores blood flow and blocks tissue necrosis and ambulatory impairment in HFD-induced hyperglycemic mice or db/db mice with diabetic hindlimb ischemia. Mechanistically, AGGF1 activates AKT, reduces nuclear localization of Fyn, which increases the nuclear level of Nrf2 and expression of antioxidative genes, and inhibits reactive oxygen species generation. These results suggest that Aggf1 is required for essential function of EPCs, AGGF1 fully reverses the damaging effects of hyperglycemia on EPCs, and AGGF1 priming of EPCs is a novel treatment modality for vascular complications in DM.


Subject(s)
Angiogenic Proteins/metabolism , Bone Marrow Cells/metabolism , Muscle, Skeletal/metabolism , Angiogenic Proteins/genetics , Animals , Cell- and Tissue-Based Therapy , Cells, Cultured , Diet, High-Fat , HEK293 Cells , Haploinsufficiency/genetics , Haploinsufficiency/physiology , Humans , Hyperglycemia/genetics , Hyperglycemia/physiopathology , Lentivirus/genetics , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Platelet Endothelial Cell Adhesion Molecule-1/genetics , Platelet Endothelial Cell Adhesion Molecule-1/metabolism
8.
J Am Heart Assoc ; 6(6)2017 Jun 25.
Article in English | MEDLINE | ID: mdl-28649088

ABSTRACT

BACKGROUND: Despite recent improvements in angioplasty and placement of drug-eluting stents in treatment of atherosclerosis, restenosis and in-stent thrombosis impede treatment efficacy and cause numerous deaths. Research efforts are needed to identify new molecular targets for blocking restenosis. We aim to establish angiogenic factor AGGF1 (angiogenic factor with G patch and FHA domains 1) as a novel target for blocking neointimal formation and restenosis after vascular injury. METHODS AND RESULTS: AGGF1 shows strong expression in carotid arteries; however, its expression is markedly decreased in arteries after vascular injury. AGGF1+/- mice show increased neointimal formation accompanied with increased proliferation of vascular smooth muscle cells (VSMCs) in carotid arteries after vascular injury. Importantly, AGGF1 protein therapy blocks neointimal formation after vascular injury by inhibiting the proliferation and promoting phenotypic switching of VSMCs to the contractile phenotype in mice in vivo. In vitro, AGGF1 significantly inhibits VSMCs proliferation and decreases the cell numbers at the S phase. AGGF1 also blocks platelet-derived growth factor-BB-induced proliferation, migration of VSMCs, increases expression of cyclin D, and decreases expression of p21 and p27. AGGF1 inhibits phenotypic switching of VSMCs to the synthetic phenotype by countering the inhibitory effect of platelet-derived growth factor-BB on SRF expression and the formation of the myocardin/SRF/CArG-box complex involved in activation of VSMCs markers. Finally, we show that AGGF1 inhibits platelet-derived growth factor-BB-induced phosphorylation of MEK1/2, ERK1/2, and Elk phosphorylation involved in the phenotypic switching of VSMCs, and that overexpression of Elk abolishes the effect of AGGF1. CONCLUSIONS: AGGF1 protein therapy is effective in blocking neointimal formation after vascular injury by regulating a novel AGGF1-MEK1/2-ERK1/2-Elk-myocardin-SRF/p27 signaling pathway.


Subject(s)
Angiogenic Proteins/administration & dosage , Carotid Artery Injuries/prevention & control , Carotid Stenosis/prevention & control , Muscle, Smooth, Vascular/drug effects , Myocytes, Smooth Muscle/drug effects , Neointima , Angiogenic Proteins/deficiency , Angiogenic Proteins/genetics , Animals , Carotid Artery Injuries/genetics , Carotid Artery Injuries/metabolism , Carotid Artery Injuries/pathology , Carotid Artery, Common/drug effects , Carotid Artery, Common/metabolism , Carotid Artery, Common/pathology , Carotid Stenosis/genetics , Carotid Stenosis/metabolism , Carotid Stenosis/pathology , Cell Line , Cell Movement/drug effects , Cell Plasticity/drug effects , Cell Proliferation/drug effects , Cyclin-Dependent Kinase Inhibitor p27/metabolism , Disease Models, Animal , Extracellular Signal-Regulated MAP Kinases/metabolism , Gene Expression Regulation , Male , Mice, Inbred C57BL , Mice, Knockout , Mitogen-Activated Protein Kinase Kinases/metabolism , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/metabolism , Myocytes, Smooth Muscle/pathology , Nuclear Proteins/metabolism , Phenotype , Phosphorylation , RNA Interference , Serum Response Factor/metabolism , Signal Transduction/drug effects , Ternary Complex Factors/metabolism , Trans-Activators/metabolism , Transfection
9.
Sci Rep ; 6: 34034, 2016 10 04.
Article in English | MEDLINE | ID: mdl-27698442

ABSTRACT

Hepatocellular carcinoma (HCC) is one of the most common malignant cancers. To elucidate new regulatory mechanisms for heptocarcinogenesis, we investigated the regulation of p21, a cyclin-dependent kinase (CDK) inhibitor encoded by CDKN1A, in HCC. The expression level of p21 is decreased with the progression of HCC. Luciferase assays with a luciferase-p21-3' UTR reporter and its serial deletions identified a 15-bp repressor element at the 3'-UTR of CDKN1A, which contains a binding site for miR-95-3p. Mutation of the binding site eliminated the regulatory effect of miR-95-3p on p21 expression. Posttranscriptional regulation of p21 expression by miR-95-3p is mainly on the protein level (suppression of translation). Overexpression of miR-95-3p in two different HCC cell lines, HepG2 and SMMC7721, significantly promoted cell proliferation, cell cycle progression and cell migration, whereas a miR-95-3p specific inhibitor decreased cell proliferation, cell cycle progression and cell migration. The effects of miR-95-3p on cellular functions were rescued by overexpression of p21. Overexpression of miR-95-3p promoted cell proliferation and tumor growth in HCC xenograft mouse models. Expression of miR-95-3p was significantly higher in HCC samples than in adjacent non-cancerous samples. These results demonstrate that miR-95-3p is a potential new marker for HCC and regulates hepatocarcinogenesis by directly targeting CDKN1A/p21 expression.


Subject(s)
Carcinoma, Hepatocellular/metabolism , Cyclin-Dependent Kinase Inhibitor p21/biosynthesis , Gene Expression Regulation, Neoplastic , Liver Neoplasms/metabolism , MicroRNAs/metabolism , RNA, Neoplasm/metabolism , Animals , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Cell Cycle/genetics , Cell Movement/genetics , Cyclin-Dependent Kinase Inhibitor p21/genetics , Hep G2 Cells , Heterografts , Humans , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Male , Mice , MicroRNAs/genetics , Neoplasm Transplantation , RNA, Neoplasm/genetics
10.
PLoS Biol ; 14(8): e1002529, 2016 08.
Article in English | MEDLINE | ID: mdl-27513923

ABSTRACT

AGGF1 is an angiogenic factor with therapeutic potential to treat coronary artery disease (CAD) and myocardial infarction (MI). However, the underlying mechanism for AGGF1-mediated therapeutic angiogenesis is unknown. Here, we show for the first time that AGGF1 activates autophagy, a housekeeping catabolic cellular process, in endothelial cells (ECs), HL1, H9C2, and vascular smooth muscle cells. Studies with Atg5 small interfering RNA (siRNA) and the autophagy inhibitors bafilomycin A1 (Baf) and chloroquine demonstrate that autophagy is required for AGGF1-mediated EC proliferation, migration, capillary tube formation, and aortic ring-based angiogenesis. Aggf1+/- knockout (KO) mice show reduced autophagy, which was associated with inhibition of angiogenesis, larger infarct areas, and contractile dysfunction after MI. Protein therapy with AGGF1 leads to robust recovery of myocardial function and contraction with increased survival, increased ejection fraction, reduction of infarct areas, and inhibition of cardiac apoptosis and fibrosis by promoting therapeutic angiogenesis in mice with MI. Inhibition of autophagy in mice by bafilomycin A1 or in Becn1+/- and Atg5 KO mice eliminates AGGF1-mediated angiogenesis and therapeutic actions, indicating that autophagy acts upstream of and is essential for angiogenesis. Mechanistically, AGGF1 initiates autophagy by activating JNK, which leads to activation of Vps34 lipid kinase and the assembly of Becn1-Vps34-Atg14 complex involved in the initiation of autophagy. Our data demonstrate that (1) autophagy is essential for effective therapeutic angiogenesis to treat CAD and MI; (2) AGGF1 is critical to induction of autophagy; and (3) AGGF1 is a novel agent for treatment of CAD and MI. Our data suggest that maintaining or increasing autophagy is a highly innovative strategy to robustly boost the efficacy of therapeutic angiogenesis.


Subject(s)
Angiogenic Proteins/metabolism , Autophagy/physiology , Heart Diseases/metabolism , Neovascularization, Pathologic/metabolism , Angiogenic Proteins/genetics , Angiogenic Proteins/pharmacology , Animals , Autophagy/drug effects , Autophagy/genetics , Autophagy-Related Protein 5/genetics , Autophagy-Related Protein 5/metabolism , Beclin-1/genetics , Beclin-1/metabolism , Blotting, Western , Cell Line , Cells, Cultured , Enzyme Inhibitors/pharmacology , Heart Diseases/drug therapy , Heart Diseases/genetics , Human Umbilical Vein Endothelial Cells/drug effects , Human Umbilical Vein Endothelial Cells/metabolism , Human Umbilical Vein Endothelial Cells/physiology , Humans , Macrolides/pharmacology , Mice, Inbred C57BL , Mice, Knockout , Muscle, Smooth, Vascular/cytology , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Myocytes, Smooth Muscle/drug effects , Myocytes, Smooth Muscle/metabolism , Neovascularization, Pathologic/drug therapy , Neovascularization, Pathologic/genetics , Neovascularization, Physiologic/drug effects , Recombinant Proteins/metabolism , Recombinant Proteins/pharmacology
11.
Hum Mol Genet ; 25(23): 5094-5110, 2016 12 01.
Article in English | MEDLINE | ID: mdl-27522498

ABSTRACT

Aggf1 is the first gene identified for Klippel-Trenaunay syndrome (KTS), and encodes an angiogenic factor. However, the in vivo roles of Aggf1 are incompletely defined. Here we demonstrate that Aggf1 is essential for both physiological angiogenesis and pathological tumour angiogenesis in vivo. Two lines of Aggf1 knockout (KO) mice showed a particularly severe phenotype as no homozygous embryos were observed and heterozygous mice also showed embryonic lethality (haploinsufficient lethality) observed only for Vegfa and Dll4. Aggf1+/- KO caused defective angiogenesis in yolk sacs and embryos. Survived adult heterozygous mice exhibit frequent haemorrhages and increased vascular permeability due to increased phosphorylation and reduced membrane localization of VE-cadherin. AGGF1 inhibits VE-cadherin phosphorylation, increases plasma membrane VE-cadherin in ECs and in mice, blocks vascular permeability induced by ischaemia-reperfusion (IR), restores depressed cardiac function and contraction, reduces infarct sizes, cardiac fibrosis and necrosis, haemorrhages, edema, and macrophage density associated with IR. Mechanistically, AGGF1 promotes angiogenesis by activating catalytic p110α subunit and p85α regulatory subunit of PI3K, leading to activation of AKT, GSK3ß and p70S6K. AKT activation is significantly reduced in heterozygous KO mice and isolated KO ECs, which can be rescued by exogenous AGGF1. ECs from KO mice show reduced capillary angiogenesis, which is rescued by AGGF1 and AKT. Tumour growth/angiogenesis is reduced in heterozygous mice, which was associated with reduced activation of p110α, p85α and AKT. Together with recent identification of somatic mutations in p110α (encoded by PIK3CA), our data establish a potential mechanistic link between AGGF1 and PIK3CA, the two genes identified for KTS.


Subject(s)
Angiogenic Proteins/genetics , Antigens, CD/genetics , Cadherins/genetics , Class I Phosphatidylinositol 3-Kinases/genetics , Klippel-Trenaunay-Weber Syndrome/genetics , Neovascularization, Pathologic/genetics , Angiogenic Proteins/biosynthesis , Animals , Antigens, CD/biosynthesis , Cadherins/biosynthesis , Class I Phosphatidylinositol 3-Kinases/biosynthesis , Embryonic Development/genetics , Haploinsufficiency/genetics , Humans , Klippel-Trenaunay-Weber Syndrome/physiopathology , Mice , Mice, Knockout , Neovascularization, Physiologic/genetics , Oncogene Protein v-akt/genetics , Phosphatidylinositol 3-Kinases/genetics , Phosphorylation , Signal Transduction/genetics
12.
PLoS Genet ; 11(8): e1005393, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26267381

ABSTRACT

Atrial fibrillation (AF) is the most common cardiac arrhythmia at the clinic. Recent GWAS identified several variants associated with AF, but they account for <10% of heritability. Gene-gene interaction is assumed to account for a significant portion of missing heritability. Among GWAS loci for AF, only three were replicated in the Chinese Han population, including SNP rs2106261 (G/A substitution) in ZFHX3, rs2200733 (C/T substitution) near PITX2c, and rs3807989 (A/G substitution) in CAV1. Thus, we analyzed the interaction among these three AF loci. We demonstrated significant interaction between rs2106261 and rs2200733 in three independent populations and combined population with 2,020 cases/5,315 controls. Compared to non-risk genotype GGCC, two-locus risk genotype AATT showed the highest odds ratio in three independent populations and the combined population (OR=5.36 (95% CI 3.87-7.43), P=8.00×10-24). The OR of 5.36 for AATT was significantly higher than the combined OR of 3.31 for both GGTT and AACC, suggesting a synergistic interaction between rs2106261 and rs2200733. Relative excess risk due to interaction (RERI) analysis also revealed significant interaction between rs2106261 and rs2200733 when exposed two copies of risk alleles (RERI=2.87, P<1.00×10-4) or exposed to one additional copy of risk allele (RERI=1.29, P<1.00×10-4). The INTERSNP program identified significant genotypic interaction between rs2106261 and rs2200733 under an additive by additive model (OR=0.85, 95% CI: 0.74-0.97, P=0.02). Mechanistically, PITX2c negatively regulates expression of miR-1, which negatively regulates expression of ZFHX3, resulting in a positive regulation of ZFHX3 by PITX2c; ZFHX3 positively regulates expression of PITX2C, resulting in a cyclic loop of cross-regulation between ZFHX3 and PITX2c. Both ZFHX3 and PITX2c regulate expression of NPPA, TBX5 and NKX2.5. These results suggest that cyclic cross-regulation of gene expression is a molecular basis for gene-gene interactions involved in genetics of complex disease traits.


Subject(s)
Atrial Fibrillation/genetics , Homeodomain Proteins/genetics , Transcription Factors/genetics , 3' Untranslated Regions , Atrial Fibrillation/metabolism , Atrial Natriuretic Factor/genetics , Atrial Natriuretic Factor/metabolism , Base Sequence , Binding Sites , Case-Control Studies , Caveolin 1/genetics , Caveolin 1/metabolism , Epistasis, Genetic , Gene Expression , Genetic Predisposition to Disease , Genome-Wide Association Study , Homeobox Protein Nkx-2.5 , Homeodomain Proteins/metabolism , Humans , MicroRNAs/genetics , Polymorphism, Single Nucleotide , RNA Interference , Transcription Factors/metabolism , Homeobox Protein PITX2
13.
Water Sci Technol ; 71(2): 283-8, 2015.
Article in English | MEDLINE | ID: mdl-25633953

ABSTRACT

Biosorption is an effective method for removing heavy metals from effluent. This work mainly aimed to evaluate the adsorption performance of the widely cultivated novel mushroom, Pleurotus eryngii, for the removal of Cu(II) from single aqueous solutions. Kinetics and equilibria were obtained using a batch technique. The sorption kinetics follows the pseudo-second-order model, whereas the adsorption equilibria are best described by the Langmuir model. The adsorption process is exothermic because both the Langmuir-estimated biosorption capacity and the heat of adsorption estimated from the Temkin model decreased with increasing tested temperature. Based on the adsorption intensity estimated by the Freundlich model and the mean adsorption free energy estimated by the Dubinin-Radushkevich model, the type of adsorption is defined as physical adsorption. The biomass of the macro-fungus P. eryngii has the potential to remove Cu(II) from a large-scale wastewater contaminated by heavy metals, because of its favorable adsorption, short biosorption equilibrium time of 20 min and remarkable biosorption capacity (15.19 mg g⁻¹ as calculated by the Langmuir model). The adsorbed metal-enriched mushroom is a high-quality bio-ore by the virtue of its high metal content of industrial mining grade and easy metal extractability.


Subject(s)
Copper/metabolism , Pleurotus/metabolism , Water Pollutants, Chemical/metabolism , Adsorption , Biodegradation, Environmental , Biomass , Copper/chemistry , Kinetics , Pleurotus/chemistry , Pleurotus/growth & development , Wastewater/chemistry , Water Pollutants, Chemical/chemistry
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