BACKGROUNDAdipocytes behave like a rich source of pro-inflammatory cytokines including monocyte chemoattractant protein-1 (MCP-1). Oxidized low-density lipoprotein (oxLDL) participates in the local chronic inflammatory response, and high-density lipoprotein could counterbalance the proinflammatory function of oxLDL, but the underlying mechanism is not completely understood. This study aimed to evaluate the effect of apolipoprotein A-I mimetic peptide L-4F on the secretion and expression of MCP-1 in fully differentiated 3T3-L1 adipocytes induced by oxLDL and to elucidate the possible mechanisms.

METHODSFully differentiated 3T3-L1 adipocytes were incubated in the medium containing various concentration of L-4F (0-50 μg/ml) with oxLDL (50 μg/ml) stimulated, with/without protein kinase A (PKA) inhibitor H-89 (10 μmol/L) preincubated. The concentrations of MCP-1 in the supernatant, the mRNA expression of MCP-1, the levels of CCAAT/enhancer binding protein α (C/EBPα), and CCAAT/enhancer binding protein β (C/EBPβ) were evaluated. The monocyte chemotaxis assay was performed by micropore filter method using a modified Boyden chamber.

RESULTSOxLDL stimulation induced a significant increase of MCP-1 expression and secretion in 3T3-L1 adipocytes, which were inhibited by L-4F preincubation in a dose-dependent manner. PKA inhibitor H-89 markedly reduced the oxLDL-induced MCP-1 expression, but no further decrease was observed when H-89 was used in combination with L-4F (50 μg/ml) (P > 0.05). OxLDL stimulation showed no significant effect on C/EBPα protein level but increased C/EBPβ protein level in a time-dependent manner. H-89 and L-4F both attenuated C/EBPβ protein level in oxLDL-induced 3T3-L1 adipocytes.

CONCLUSIONSOxLDL induces C/EBPβ protein synthesis in a time-dependent manner and enhances MCP-1 secretion and expression in 3T3-L1 adipocytes. L-4F dose-dependently counterbalances the pro-inflammatory effect of oxLDL, and cyclic AMP/PKA-C/EBPβ signaling pathway may participate in it.

3T3-L1 Cells ; Animals ; CCAAT-Enhancer-Binding Protein-beta ; analysis ; physiology ; Chemokine CCL2 ; genetics ; secretion ; Cyclic AMP ; physiology ; Cyclic AMP-Dependent Protein Kinases ; physiology ; Humans ; Lipoproteins, LDL ; antagonists & inhibitors ; pharmacology ; Mice ; Peptides ; pharmacology ; Signal Transduction ; physiology

In order to investigate the roles of Wnt signal pathway in transformation of cardiac valvular myofibroblasts to the osteoblast-like phenotype, the primary cultured porcine aortic valve myofibroblasts were incubated with oxidized low density lipoprotein (ox-LDL, 50 mg/L), and divided into four groups according to the ox-LDL treatment time: control group, ox-LDL 24-h group, ox-LDL 48-h group, and ox-LDL 72-h group. Wnt signal pathway blocker Dickkopf-1 (DDK-1, 100 μg/L) was added in ox-LDL 72-h group. The expression of a-smooth muscle actin (α-SMA), bone morphogenetic protein 2 (BMP2), alkaline phosphatase (ALP), and osteogenic transcription factor Cbfa-1 was detected by Western blotting, and that of β-catenin, a key mediator of Wnt signal pathway by immunocytochemical staining method. The Wnt/β-catenin was observed and the transformation of myofibroblasts to the osteoblast-like phenotype was examined. The expression of α-SMA, BMP2, ALP and Cbfa-1 proteins in the control group was weaker than in the ox-LDL-treated groups. In ox-LDL-treated groups, the protein expression of a-SMA, BMP2, ALP, and Cbfa-1 was significantly increased in a time-dependent manner as compared with the control group, and there was significant difference among the three ox-LDL-treated groups (P<0.05 for all); β-catenin protein was also up-regulated in the ox-LDL-treated groups in a time-dependent manner as compared with the control group (P<0.05), and its transfer from cytoplasm to nucleus and accumulation in the nucleus were increased in the same fashion (P<0.05). After addition of DKK-1, the expression of α-SMA, bone-related proteins and β-catenin protein was significantly reduced as compared with ox-LDL 72-h group (P<0.05). The Wnt/ β-catenin signaling pathway may play an important role in transformation of valvular myofibroblasts to the osteoblast-like phenotype.
Actins ; metabolism ; Animals ; Aortic Valve ; cytology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Gene Expression Regulation ; drug effects ; Intercellular Signaling Peptides and Proteins ; pharmacology ; Lipoproteins, LDL ; pharmacology ; Myofibroblasts ; drug effects ; Osteoblasts ; physiology ; Phenotype ; Swine ; Wnt Signaling Pathway ; drug effects ; beta Catenin ; metabolism

OBJECTIVETo explore the molecule mechanism of Salidroside inducing directional differentiation of mouse mesenchymal stem cells (MSCs) into neuronal cells.

METHODSThe mouse multipotent mesenchymal precursor cell line (D1) was taken as the objective. Cultured MSCs were divided into the negative control group (complete culture solution), the positive control group (containing 1 mmol/L β-mercaptoethanol), the Salidroside induced group (20 mg/L Salidroside), and the blocked group (20 ng/ ml DKK1, a special inhibitor of Wnt/β-catenin signal pathway). All cells were inoculated in a 6-well plate (1 x 10(4) cells/cm2) and grouped for 24 h. The expression of p-catenin was detected by fluorescence Immunochemistry in the negative control group, the positive control group, and the Salidroside induced group. The expression of neuron-specific enolase (NSE), beta 3 class III tubulin (β-tubulin III), nuclear receptor related factor 1 (Nurr1), glial fibrillary acidic protein (GFAP) mRNA, Wnt3a, β-catenin, low-density lipoprotein receptor-related protein6 (LRP6), Axin mRNA were detected using reverse transcrip- tion PCR (RT-PCR). The expression of β-catenin and NSE protein were analyzed by Western blot in the negative control group, the positive control group, and the Salidroside induced group. Ca2+ chelating agents (EGTA), L-type Ca2+ channel blocker (Nifedpine), and IP3Ks special inhibitor (LY294002) were used to block Ca2+ signal pathway respectively. The expression of Wnt3a, LRP-6, Axin, glycogen syn- thase kinase (GSK-3), and β-catenin mRNA were detected by RT-PCR. The β-catenin protein expression was analyzed using Western blot.

RESULTSCompared with the positive control group, β-catenin protein was strong positively expressed; the expression of Wnt3a, β-catenin, LRP6, Axin, NSE, β-tubulin III, Nurr1 mRNA, and NSE protein were obviously up-regulated in the Salidroside induced group (P < 0.01). Compared with the positive control group and the Salidroside induced group, β-catenin, NSE, Nurr1, and β-tubulin III mRNA expression decreased; β-catenin and NSE protein expression were also down-regulated in the blocked group (P < 0.01). Compared with the Salidroside induced group, the expression of Wnt3a, LRP-6, β-catenin, and Axin mRNA were down-regulated in the Ca2+ signal blocked group and the salidroside induced group (P < 0.01, P < 0.05).

CONCLUSIONSalidroside affected directional differentia- tion of MSCs into neuronal cells through Wnt/β-catenin and Ca2+ signal pathway.

Animals ; Cell Differentiation ; drug effects ; Glucosides ; pharmacology ; Glycogen Synthase Kinase 3 ; Lipoproteins, LDL ; Low Density Lipoprotein Receptor-Related Protein-6 ; Mesenchymal Stromal Cells ; physiology ; Mice ; Neurons ; Phenols ; pharmacology ; Phosphopyruvate Hydratase ; RNA, Messenger ; Signal Transduction ; Wnt Signaling Pathway ; physiology ; beta Catenin ; metabolism

Aortic valve calcification is a common disease in the elderly, but its cellular and molecular mechanisms are not clear. In order to verify the hypothesis that Wnt/β-catenin signaling pathway is involved in the process of calcification of aortic valve, porcine aortic valve interstitial cells (VICs) were isolated, cultured and stimulated with oxidized low density lipoprotein (ox-LDL) for 48 h to induce the differentiation of VICs into osteoblast-like cells. The key proteins and genes of Wnt/β-catenin signaling pathway, such as glycogen synthase kinase 3β (GSK-3β) and β-catenin, were detected by using Western blotting and real-time polymerase chain reaction (PCR). The results showed that the VICs managed to differentiate into osteoblast-like cells after the stimulation with ox-LDL and the levels of proteins and genes of GSK-3β and β-catenin were increased significantly in VICs after stimulation for 48 h (P<0.05). It is suggested that Wnt/β-catenin signaling pathway may play a key role in the differentiation of VICs into osteoblast-like cells and make great contribution to aortic valve calcification.
Alkaline Phosphatase ; genetics ; metabolism ; Animals ; Aortic Valve ; metabolism ; pathology ; Aortic Valve Stenosis ; Blotting, Western ; Bone Morphogenetic Protein 2 ; genetics ; metabolism ; Calcinosis ; Cell Differentiation ; drug effects ; genetics ; Cells, Cultured ; Gene Expression ; drug effects ; Glycogen Synthase Kinase 3 ; genetics ; metabolism ; Lipoproteins, LDL ; pharmacology ; Osteoblasts ; drug effects ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Swine ; Wnt Signaling Pathway ; genetics ; physiology ; beta Catenin ; genetics ; metabolism

OBJECTIVETo investigate the effects of non-neuronal muscarinic receptors (NNMR) stimulation on atherosclerosis and endothelial cells activation.

METHODSAtherosclerosis model was established in ApoE-/- mice by a high fat diet for 7 weeks. During the experimental periods, animals were received a low (7 mg/kg/d) or a high (21 mg/kg/d) dose of arecoline by gavage. At the termination of the treatments, serum total cholesterol and NO levels were measured, and the aorta morphology was analyzed by hematoxylin and eosin staining. The gene expression of monocyte chemoattractant protein-1 (MCP-1) and adhesion molecules in the thoracic aortas was determined by RT-PCR, and the MCP-1 protein expression and NF-κB activity were detected by Western blot analysis. NO production, MCP-1 secretion in cultured rat aortic endothelial cells (RAECs), and monocyte-endothelium adhesion assay were also performed after arecoline treatments.

RESULTSArecoline efficiently decreased atherosclerotic plaque areas, increased serum nitric oxide (NO) content, suppressed the mRNA and protein expression of MCP-1, and modulated the IκB-α degradation and P65 phosphorylation in the aortae of ApoE-/- mice. Furthermore, arecoline promoted NO production and suppressed MCP-1 secretion in cultured RAECs after ox-LDL exposure, and either atropine or NG-nitro-L-arginine methylester could abrogate these effects. Arecoline also significantly inhibited the adherence of U937 monocytes to the ox-LDL injured human umbilical vein endothelial cells, which could be abolished by atropine.

CONCLUSIONOur results indicate that arecoline attenuates the progression of atherosclerosis and inhibits endothelial cells activation and adherence by stimulating endothelial NNMR. These effects, at least in part, are due to its modulation on NF-κB activity.

Animals ; Aorta ; cytology ; Apolipoproteins E ; Arecoline ; pharmacology ; Atherosclerosis ; physiopathology ; prevention & control ; Cell Adhesion Molecules ; metabolism ; Chemokine CCL2 ; metabolism ; Cholesterol ; blood ; Disease Progression ; Endothelial Cells ; cytology ; drug effects ; Endothelium, Vascular ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; I-kappa B Proteins ; metabolism ; Lipoproteins, LDL ; Mice ; Mice, Knockout ; Monocytes ; cytology ; NF-KappaB Inhibitor alpha ; Nitric Oxide ; blood ; Nitroarginine ; pharmacology ; Rats ; Receptors, Muscarinic ; physiology ; Transcription Factor RelA ; metabolism

This study is to investigate the impairment and possible mechanism of endothelium-dependent relaxation of mice mesenteric arteries induced by mmLDL. Wire myography was employed to examine endothelial function of mesenteric arteries. Ultramicrostructure of mesenteric vascular beds were detected by transmission electron microscope. The results showed that endothelium cell edema and peeling, vascular elastic membrane fracture traces in mmLDL group. Endothelium-dependent relaxation was decreased in a time-dependent and dose-dependent manner by using mmLDL, compared with normal arteries. In endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxation, the Rmax and pIC50 were decreased from (63 +/- 5) % and 6.42 +/- 0.09 of normal saline control to (31 +/- 3) % and 5.67 +/- 0.07 in mmLDL group (P < 0.001, P < 0.001), respectively. In nitric oxide (NO)-mediated relaxation, the Rmax and pIC50 were decreased from (45 +/- 4) % and 5.93 +/- 0.08 in normal saline control to (32 +/- 4) % and 5.43 +/- 0.11 in mmLDL group (P < 0.05, P < 0.01), respectively. There is no significant alteration of prostacyclin I2 (PGI2) pathway between these two groups. In conclusion, mmLDL induced the impairment of the ultramicrostructure of mesenteric vascular endothelium cell as well as the endothelium-dependent relaxation. The latter includes the dysfunction of NO- and EDHF pathway mediated endothelium-dependent relaxation.
Animals ; Biological Factors ; antagonists & inhibitors ; physiology ; Dose-Response Relationship, Drug ; Endothelial Cells ; drug effects ; ultrastructure ; Epoprostenol ; antagonists & inhibitors ; physiology ; Female ; Lipoproteins, LDL ; administration & dosage ; pharmacology ; Male ; Mesenteric Arteries ; cytology ; physiology ; ultrastructure ; Mice ; Mice, Inbred ICR ; Microscopy, Electron, Transmission ; Nitric Oxide ; antagonists & inhibitors ; physiology ; Vasodilation ; drug effects

OBJECTIVE: To investigate the relationship between insulin-like growth factor-1 (IGF-1) in the serum and the vascular endothelial function in patients with hypercholesterolemia and the underlying mechanism. METHODS: We examined the flow-mediated arterial diastolic function (FMD), the levels of IGF-1, asymmetric dimethylarginine (ADMA), NO, and the activity of nitric oxide synthase (NOS) in the serum from 25 patients with hypercholesterolemia and from healthy controls. An endothelial cell injury model was established by incubation of the human umbical vein endothelial cells (HUVECs) with oxidized low-density lipoprotein (ox-LDL) for 24 hours. Cells were treated with IGF-1 30 min before ox-LDL treatment. The levels of ADMA, NOS, and NO in the cell supernatant, the activity of dimethylarginine dimethylamine hydrolase (DDAH) in the cell lysate were measured. Beta-galactosidase staining was used to assess the degree of endothelial cell senescence by calculating the senescence rate of cells. RESULTS: Compared with the control group, the FMD, the levels of IGF-1 and NO, and the activity of NOS in the serum from patients with hypercholesterolemia decreased significantly accompanied with a dramatic increase at ADMA level. Multiple linear regression analysis showed that the change in IGF-1 was positively correlated with FMD while the change in ADMA was negatively correlated with FMD. Compared with the control group, ox-LDL treatments significantly decreased the activities of DDAH and NOS, and the level of NO, accompanied with an increase in ADMA. Betagalactosidase staining showed that the senescence rate of cells increased in the ox-LDL group. The effect of ox-LDL on HUVECs was significantly attenuated at the presence of IGF-1. CONCLUSION The decrease in IGF-1 in the peripheral blood may contribute to vascular endothelial dysfunction in patients with hypercholesterolemia. IGF-1 can protect HUVECs against ox-LDL-induced senescence, which is likely involved in the regulation of DDAH/ADMA pathway.
Adult ; Arginine ; analogs & derivatives ; blood ; Case-Control Studies ; Cells, Cultured ; Endothelium, Vascular ; physiology ; Female ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Hypercholesterolemia ; blood ; physiopathology ; Insulin-Like Growth Factor I ; metabolism ; physiology ; Lipoproteins, LDL ; pharmacology ; Male ; Middle Aged ; Nitric Oxide ; blood ; Protective Agents ; metabolism ; Vasodilation ; physiology

OBJECTIVETo explore the effectiveness related indicators which might help identify the indications of Tongxinluo Capsule () and Kangxin Capsule () targeting on qi deficiency and blood stasis pattern in Chinese medicine (CM) in the treatment of angina pectoris.

METHODSThe data from a multicenter, randomized and double-blinded study conducted at 5 centers in China were obtained for the analysis. A total of 239 patients with angina pectoris and CM syndrome of qi deficiency and blood stasis were randomly assigned in a 1:1 ratio to Tongxinluo Capsule group (119 cases) and Kangxin Capsule group (120 cases). Angina effectiveness and electrocardiogram (ECG) improvement were selected as the therapeutic outcomes.

RESULTSAfter a 4-week treatment, the effective rates of Tongxinluo Capsule and Kangxin Capsule were 43.70% and 25.00%, respectively (P <0.05). Serum low-density lipoprotein (LDL) level was found to influence the effectiveness of Tongxinluo Capsule which had higher effective rate in the patients with lower level of LDL. Heart rate was found to influence the effectiveness in the patients treated with Kangxin Capsule which had higher effective rate in the patients with heart rate [Symbol: see text]80 beats/min.

CONCLUSIONLDL level and heart rate were the indicators which help indentify the indications of Tongxinluo Capsule and Kangxin Capsule, respectively, in the treatment of angina pectoris with CM syndrome of qi deficiency and blood stasis.

Adult ; Aged ; Angina Pectoris ; blood ; drug therapy ; physiopathology ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Heart Rate ; drug effects ; physiology ; Humans ; Lipoproteins, LDL ; blood ; Male ; Middle Aged ; Patient Dropouts ; Platelet Count ; Treatment Outcome

PURPOSE: Stimulation of human aortic smooth muscle cells (hAoSMCs) with native low-density lipoprotein (nLDL) induced the production of interleukin-8 (IL-8) that is involved in the pathogenesis of cardiovascular diseases. However, the process of signal transduction of nLDL was currently uncharacterized. Therefore, the aim of this study was to investigate the signal transduction pathway of nLDL-dependent IL-8 production and the effect of IL-8 on hAoSMCs migration. MATERIALS AND METHODS: nLDL was prepared by ultracentrifugation with density-adjusted human serum of normocholesterolemia. In hAoSMCs, IL-8 secreted to medium was measured using ELISA assay, and Western blot analysis was performed to detect p38 MAPK activation as a key regulator of IL-8 production. nLDL-dependent H2O2 generation was determined by microscopic analysis using 2',7'-dichlorofluoroscein diacetate (DCF-DA). IL-8-induced migration of hAoSMCs was evaluated by counting the cell numbers moved to lower chamber using Transwell plates. RESULTS: nLDL-induced IL-8 production was completely blocked by preincubation of hAoSMCs with pertussis toxin (PTX), which inhibited nLDL-dependent p38 MAPK phosphorylation. PTX-sensitive G-protein coupled receptor was responsible for nLDL-dependent H2O2 generation that was abrogated with preincubation of the cells with of polyethylene glycol-conjugated catalase (PEG-Cat). Pretreatment of PEG-Cat prevented nLDL-induced p38 MAPK phosphorylation and IL-8 production, which was partly mimicked by treatment with exogenous H2O2. Finally, IL-8 increased hAoSMCs migration that was completely blocked by incubation with IL-8 neutralizing antibody. CONCLUSION: PTX-sensitive G-protein coupled receptor-dependent H2O2 generation by nLDL plays a critical role in IL-8 production in hAoSMC, and IL-8 may contribute to atherogenesis through increased migration of hAoSMCs.
Cell Movement/*physiology ; Cells, Cultured ; Humans ; Hydrogen Peroxide/*metabolism ; Interleukin-8/*biosynthesis ; Lipoproteins, LDL/*pharmacology ; Muscle, Smooth, Vascular/cytology/*metabolism ; Myocytes, Smooth Muscle/cytology/*metabolism ; Pertussis Toxin/pharmacology ; Phosphorylation/drug effects ; Reactive Oxygen Species/metabolism ; Receptors, G-Protein-Coupled/*physiology ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases/metabolism

OBJECTIVETo establish the model of bone mesenchymal stem cell-derived smooth muscle cells (BMSC-SMCs) and investigate the role of BMSC-SMCs in the development and progression of artherosclerosis.

METHODSBMSCs were isolated from the femoral bone of SD rats by adherent tissue culture method, and vascular smooth muscle cells (VSMCs) were obtained from the thoracic aorta. The differentiation of BMSCs into BMSC-SMCs was induced in the conditioned medium. The specific markers of BMSCs and BMSC-SMCs were identified by immunofluorescence (IF) staining. After treatment with 80 mg/L oxidative low-density lipoprotein (ox-LDL) for 72 h, the growth characteristics of BMSC-SMCs and VSMCs were observed. Flow cytometry was applied to analyze the cell cycle of BMSC-SMCs and VSMCs.

RESULTSBMCS-SMCs transformed into foam cells after treatment with ox-LDL, which was more obvious in comparison with VSMCs. The growth curve of BMSC-SMCs and VSMCs presented with an S-shape pattern with the cell doubling time of 20 and 32 h, which was reduced to 15 and 28 h after treatment with 80 mg/L ox-LDL, respectively. Flow cytometry showed that exposure to 80 mg/L ox-LDL significantly increased G(0)/G(1) and decreased S and G(2)/M phase cells in both BMSC-SMCs (P<0.01, n=3) and VSMCs (P<0.05, n=3) in comparison with the control cells.

CONCLUSIONBMSC-SMC might be involved in the formation of fatty core and accelerate the development of atherosclerosis.

Animals ; Atherosclerosis ; etiology ; Bone Marrow Cells ; cytology ; Cell Differentiation ; physiology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Female ; Foam Cells ; cytology ; Lipoproteins, LDL ; pharmacology ; Male ; Mesenchymal Stromal Cells ; cytology ; Muscle, Smooth, Vascular ; cytology ; Rats ; Rats, Sprague-Dawley