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Objective To investigate the functions of Monocyte chemotactic protein-induced protein 1 (MCPIP1) in human breast cancer cell line MDA-MB-231.Methods MDA-MB-231 cells were transfected with GFP-tagged MCPIP1 by Tet-on inducing expression system.Endogenous MCPIP1 was knocked down by stable expressing shRNA.MTT assay was performed to measure the growth of MDA-MB-231 cells after overexpression or knockdown of MCPIP1.FACS method was used to analyze cell cycle in MDA-MB-231 cells.Real-time PCR was used to test the expression of cell cycle-related mRNAs expression and their half-lives.RNA-IP experiment was conducted to detect the mRNA directly enriched by MCPIP1.Luciferase assay was performed to determine whether the mRNA decay was mediated through 3′UTR.Results MCPIP1 overexpression significantly inhibited cell proliferation(P<0.05), while knockdown MCPIP1 promoted cell proliferation with statistical significances (P<0.05).MCPIP1 induced cell cycle arrest in MDA-MB-231 with statistical significance (P<0.01).MCPIP1 overexpression reduced the half-lives of cell cycle mRNAs (CDK2,CDK6,cyclin D1,cyclin E1,respectively) with significance (P<0.01).In addition, cell cycle-related mRNAs were able to be pulled down by GFP-MCPIP1 but not isotype IgG(P<0.05).Compared with control vector, MCPIP1 significant suppressed luciferase activities of all four 3′UTR reporters (P<0.05).Conclusions MCPIP1 functions as a tumor suppressor in human breast cancer cell line MDA-MB-231 through inducing G1 cell cycle arrest.
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Microcirculation dysfunction is involved in the onset of diabetes and its complications.The pathophysiological mechanisms behind the relationship between microcirculation and diabetes are multifactorial.Islet microcirculation dysfunction affects function of islet β cells.Impairment of microvascular vasomotion might be associated with insulin resistance.Microcirculation dysfunction of target organs mediates diabetic complications.
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AIM:ToinvestigatetheultrastructuralchangesofisletmicrovascularendothelialcellsinSTZ-in-duced type 1 diabetic mice .METHODS:BALB/c mice were randomly divided into diabetic group and control group .The expression of insulin and platelet-endothelial cell adhesion molecule-1 ( CD31) in islet microvessels was detected by immu-nohistochemical staining .The ultrastructural changes of islet βcells and islet microvessels were observed under transmis-sion electron microscope .RESULTS:Compared with control group , the number of islet βcells, ratio of βcells/αcells, average number of secretory granules in βcells and insulin expression area per islet in diabetic group were significantly de-creased (P<0.01).Besides, diabetic group had fewer microvessels with lower expression of CD 31 (P<0.01).Mito-chondria in islet microvascular endothelial cells and pericytes in diabetic group were swelling .The basement membrane of islet microvessels became thicker in diabetic group ( P<0.01 ) .CONCLUSION: Islet microvascular endothelial cells were impaired in type 1 diabetic mice .
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<p><b>BACKGROUND</b>Pericytes, located on microvessels, help to maintain vascular stability and blood-brain barrier integrity. The influence of pericytes on microvessels after spinal cord injury (SCI) is less clear. Therefore, the aim of this study was to investigate whether pericytes took a protective effect on microvessels in melatonin-treated SCI.</p><p><b>METHODS</b>C57BL/6 mice were randomly divided into three groups: sham group, SCI group, and melatonin group (n = 27 per group). Functional recovery was evaluated using the Basso Mouse Scale. Motor neurons were observed using hematoxylin and eosin staining. Pericyte coverage was analyzed using immunofluorescence. Permeability of blood-spinal cord barrier (BSCB) was assessed by administration of Evan's Blue. Protein levels of occludin, aquaporin-4 (AQP4), angiopoietin-1 (Ang1), intercellular cell adhesion molecule-1 (ICAM-1), Bcl-2, and Bax were determined using Western blotting. Mimicking the pathological conditions of SCI, melatonin-treated primary pericytes were subjected to oxygen-glucose deprivation/reperfusion (OGD/R). Secretion of Ang1 was analyzed using an enzyme-linked immunosorbent assay, and the expression of ICAM-1 was detected by immunofluorescence.</p><p><b>RESULTS</b>Melatonin treatment improved locomotor functional outcome and rescued motor neurons. Pericyte coverage was significantly reduced after SCI; melatonin treatment alleviated the loss of pericyte coverage and rescued perfused microvessels 7 days after injury. The permeability of BSCB and loss of occludin were attenuated, and edema formation and upregulation of AQP4 were inhibited, after melatonin treatment. The expression of Ang1 and Bcl-2 was improved, while the expression of ICAM-1 and Bax was inhibited, in melatonin-treated SCI mice. Furthermore, the secretion of Ang1 was increased and the expression of ICAM-1 was inhibited in melatonin-treated pericytes after OGD/R.</p><p><b>CONCLUSIONS</b>Melatonin ameliorated the loss of blood vessels and disruption of BSCB to exert a protective effect on SCI, which might be mediated by increased pericyte coverage. The upregulation of Ang1 in pericytes could inhibit inflammation and apoptosis to protect the microvessels.</p>
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Animals , Male , Mice , Angiopoietin-1 , Metabolism , Enzyme-Linked Immunosorbent Assay , Intercellular Adhesion Molecule-1 , Metabolism , Melatonin , Pharmacology , Therapeutic Uses , Mice, Inbred C57BL , Microvessels , Cell Biology , Occludin , Metabolism , Pericytes , Metabolism , Random Allocation , Spinal Cord Injuries , Drug Therapy , MetabolismABSTRACT
Via activating G-protein receptor transduction pathways,nitric oxide (NO),an important signal molecule,has a complex and diverse role which is closely related with activity and gene expression of nitric oxide synthetase (NOS).NO is involved in tumor related events such as cellular proliferation,migration,especially the angiogenic process,and it is closely related with the occurrence and progression of prostate cancer.NO donors and NOS inhibitors have anti-cancer and radio-chemotherapy enhancement roles.
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Objective To establish a stable in vitro model of blood-brain barrier (BBB) simulating in vivo state using the primary-cultured rat brain microvascular endothelial cells (BMVECs) and pericytes.Methods The primary rat BMVECs and pericytes were isolated,purified and cultured.The isolated cells were identified by immunocytochemical staining method.An in vitro model of BBB was constructed using Transwell inserts (pore size 0.4 μm) coculture.Its barrier function was evaluated by the 4-hour leakage test,tight junction protein identification,transendothelial resistance detection,and permeability test.The difference between the cocultured model and simple BMVEC model across the membrane resistance values,and the permeability difference of the small molecule sodium fluorescein (Na-F) were compared.Results Confluent BMVEC monolayers demonstrated a typical cobblestone appearance and the pericytes displayed irregular shape and overlapping growth.Immunodouble labeling technique identification showed that the pericytes positively expressed α-srmooth muscle actin (α-SMA) and neuron-glial antigen 2 (NG2); after the fusion of cocultured model endothelial cells,the surface leakage test became positive; immnocytochemical staining shows that a continuous and dense tight junction formed between the endothelial cells; compared to the BMVEC model,the transendothelial electrical resistance of the cocultured model increased significantly (190.762 ± 10.326 Ω/cm2 vs.96.503 ± 8.012 Ω/cm2; t=- 24.489,P ＜0.01),and the permeability decreased significantly (56.149％ ± 3.572％ of the single endothelial model; t =19.330,P ＜ 0.01 ).Conclusions The primary isolated rat BMVECs and pericytes cocultured the morphology,structure and barrier function of in vitro model have the basic characteristics of BBB,and they have provided a useful tool for the research of BBB.
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ObjectiveTo observe the influence of polyethylene glycol-conjugated hemoglobin (PEG-Hb) solution combined with cisplatin on the expression of erythropoietin/erythropoietin receptor (EPO/EPOR) and tumor angiogenesis in cancer treatment.MethodsHeLa cells were injected subcutaneously into the right oxter of 3-4 weeks old BALB/c nude mice to establish cervical tumor xenograft model.Then animals were randomly assigned to 4 groups (n=10) and treated respectively:group 1(control); group 2,cisplatin (5 mg/kg); group 3,PEG-Hb (0.6 g/kg); group 4 cisplatin (5 mg/kg) plus PEG-Hb (0.6 g/kg).The volume oftumors in each groups were measured in 4 weeks treatment period.Efficacy was measured as percent tumor growth inhibition (TGI) relative to salinetreated group.CD31 was detected by immunohistochemistry and its expression was identified as microvascular density (MVD).Expressions of hypoxia inducible factor-1α(HIF-1α) and EPO/EPOR in tumor tissues were analyzed by irnmunohistochemistry.EPOR protein level was tested by western blot.ELISA method was used in measuring EPO concentration in serum.ResultsTumor volume was significantly decreased in group 4 compared with other groups.Immunoreactivity data demonstrated lower expression of CD31,HIF-1α and EPO/EPOR in group 4.The expression of EPOR in the endothelial cells was also significantly decreased in group 4.Western-blot data indicated lower EPOR protein level in group 4.Serum level of EPO was also decreased in group 4.ConclusionPEG-Hb plus cisplatin is benefit to tumor tissue oxygenation,therefore it can inhibit the tumor angiogenesis and down regulate the erythropoietin/erythropoietin receptor system.The result can provide more evidence for the enhanced sensitivity effect of the artificial oxygen carrier in cancer therapy.
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Objective To explore the method of primary isolation, cultivation and identification of rat brain microvessel pericytes. Methods The brain tissue of 10 3 week-old Wistar rats was separated sterilely. The brain microvessel fragments were separated using two-step enzyme digestion and one-step gradient centrifugation and were seeded in 35-mm dishes for primary culture. The cell morphology was observed by phase contrast microscopy; the immunofluorescence assay was used to identify the associated antigns, such as the α-smooth muscle actin (α-SMA), neuron-glial antigen 2 (NG2), von Willebrand factor (vWF), and glial fibrillary acidic protein (GFAP). Methyl thiazolyl tetrazolium was used to determine the cell growth curve. Results Pericytes climbed out from the adherent brain microvascular fragments around,showing polygonal, and the cell fusion was 95％ after 12-14 days. Immunofluorescence staining revealed that the molecular markers of the pericytes α-SMA and NG2 related antigens showed double positive, while the vWF and GFAP related antigens showed double negative and the cultured cells were confirmed as brain microvascular pericytes. The growth rate of primary cells was slower. The passage cells entered into logarithmic growth phase after 36 to 60 hours and entered into plateau phase after 72 to 108 hours. Conclusions This method may successfully isolate rat brain microvascular pericytes with higher purity.
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Peroxisome proliferation-activated receptor-γ (PPAR-γ) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily and participates in the regulation of various metabolic pathways as well as inflammatory responses. PPAR-γ ligands significantly improve myocardial functional recovery and prevent ischemia-reperfusion induced injury. Given the increasing understanding of the cardioprotective effects of PPAR-γ ligands, we know today that the therapeutic effects of PPAR-γ ligands reach far beyond their use as insulin-sensitizers, as many of these agents exert beneficial effects in the conditions associated with ischemia-reperfusion and inflammation.
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Pericytes are a very important cellular constituent of the blood-brain barrier.They play a regulatory role in brain angiogenesis,endothelial cell tight junction formation,blood-brain barrier differentiation,microvascular dynamic motion and structural stability.Pericytes exhibit unique functional characteristics in some diseases,such as cerebrovascular disease,neurodegenerative disease,neuroimmune disease and traumatic brain injury.This article reviews the roles of pericytes in the blood-brain barrier.
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Objective To investigate the effect of cobalt chloride on tumor cell proliferation and apoptosis in vitro, to explore the reasonable strategy of chemical hypoxia induced by CoCl2. Methods Two tumor cell lines (A549 and HeLa) were respectively exposed to CoCl2(0.05～2 mmol/L) for different time period (4～48 h), cells viability、proliferation and apoptosis were maesured by MTT and FCM methods. HIF-1? and related apoptosis proteins expression were detected by Western blot. Results Cells viability was weakly changed in low concentration(≤200 ?mol/L)of CoCl2 within 24 h. However, higher dose or prolonged challenge of CoCl2 significantly decreased cell survival rate (P
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Objective To investigate the effect of trastuzumab,a special blocker of epidermal growth factor receptor-2(HER-2) on proliferation and apoptosis of human umbilical vein endothelial cells(HUVECs) exposed to tumor conditioned medium(TCM).Methods HUVECs were cultured and exposed to TCM and trastuzumab was used as an intervention approach.Their proliferation,apoptosis and cell cycle distribution were measured by MTT and flow cytometery(FCM).Intra-tumor microvessel density(MVD) and HER-2 expression were tested by immunohistochemistry(IHC).Results Following the stimulation of MDA-CM,HUVECs showed higher proliferating and anti-apoptotic ability(P
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Objective To investigate the effect of Akt on cardiomyocyte hypertrophy induced by hydrogen peroxide(H2O2).Methods The neonatal rat cardiomyocytes cultured in primary generation were treated with low concentrations of H2O2.The cardiomyocyte hypertrophy was evaluated by the determination of average cell volume and protein content.The effects of Akt inhibitor on cardiomyocyte hypertrophy induced by H2O2 was recorded.Western blot was performed to examine the phosphorylation of Akt induced by H2O2.ResultsH2O2 at 10 or 50 ?mol/L stimulated cardiomyocyte enlargement as measured by cell volume and the protein content per cell.The inhibitor of Akt inhibited the hypertrophic response of cardiomyoctes stimulated by H2O2.H2O2 increased the level of Akt phosphorylation in cardiomyocytes,while that is suppressed by the inhibitors of PI3K(phosphoinositide 3-kinase). Conclusion Akt signaling is involved in cardiomyocyte hypertrophy induced by H2O2.
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Objective To construct pGL3-EPO-HRE reporter gene vector and to detect its function.Methods To synthesize two single-strand DNA fragments which had overlap sequence at the 3'end,then mixed them to construct the double-strand DNA fragment which include three copies of(57 bp) human erythropoietin(EPO) HRE.There was MluⅠor BglⅡ digestive site at the end of this DNA fragment.After inserting the(87 bp) fragment into pMD18-T for sequencing,the correct sequence was inserted into pGL3-promoter to construct pGL3-EPO-HRE.The recombinant vector was co-transfected into MCF-7 cells with pcDNA3-HIF-1?or pcDNA3 respectively,(12 h) later cells were treated with(100 ?mol/L) cobalt chloride(CoCl_(2)) for(24 h), then the expression of pGL3-EPO-HRE was observed by dual-luciferase reporter gene assay method.Results The sequence of pGL3-EPO-HRE was identical with human EPO HRE sequence.pGL3-EPO-HRE luciferase activity increased about 10 fold(P
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Objective To construct pcDNA3-HIF-1? eukaryotic expression vector and to investigate its function in breast cancer MCF-7 cells.Methods RT-PCR was applied to amplify human HIF-1? cDNA from MCF-7 cells with a pair of sequence specific primers carrying a restriction enzyme site XbaⅠ or HindⅢ on each 5′end.HIF-1?(cDNA) was inserted into pMD18-T after sequencing,and then inserted into pcDNA3 vector.The recombinant vector was transfected into MCF-7 cells to observe its expression and function by Western blot and dual-luciferase reporter gene assay.Realtime-PCR was performed to detect the inducible expression of C-MET mRNA by HIF-1?,the anti-apoptotic effect of HIF-1 under hypoxia was analysed by detecting the Caspase3/7 activity.Results The sequence of pcDNA3-HIF-1? is identical with the gene bank.It enhances the expression of HRE reporter gene and C-MET mRNA,but decreases the Caspase3/7 activity in MCF-7 cells under hypoxia.Conclusion The pcDNA3-HIF-1? eukaryotic expression vector was successfully constructed,it not only has strong DNA binding and inducing activity,but also has anti-apoptotic effect in hypoxia MCF-7 cells.
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Objective To isolate CESs by dynabeads coated with the specific antibody of CD146 from peripheral blood and its origin was identified.Methods One mL blood with or without admixed HUVECs was diluted(1∶2) in PBS-0.1% BSA.Anti-CD146-coated Dynabeads were added and incubated for 30mins at(4 ℃).Cells bound to anti-CD146-coupled beads were separated from blood in Dynal MPC and then washed and resuspended in(4 mL) buffer.After 4 additional washes with PBS-0.1% BSA using the magnet,the rosetted cells were flushed from the tube wall with (100 ?L) of PBS-BSA with acridine orange or Giemsa,and counted in a hemocytometer in a inverse phase contrast fluorescence microscope.Results The amount of CECs in healthy adult was 10.5(6～16.5)/mL(n=42).The recovery rate was 91%.Isolated CECs were confirmed by positive expression of vWF and CD31.Conclusion Isolation of CECs from blood by immunomagnetic beads coated with antibody of CD146 is characterized by its accuracy,time-saving,high recovery rate,less contaimination of blood and less damage to CECs.It can be used to quantify CECs and to analyze the functional performance of CECs from patients with vascular injury diseases.
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Peroxisome proliferation-activated receptor-? (PPAR-?) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily and participates in the regulation of various metabolic pathways as well as inflammatory responses. PPAR-? ligands significantly improve myocardial functional recovery and prevent ischemia-reperfusion induced injury. Given the increasing understanding of the cardioprotective effects of PPAR-? ligands,we know today that the therapeutic effects of PPAR-? ligands reach far beyond their use as insulin-sensitizers,as many of these agents exert beneficial effects in the conditions associated with ischemia-reperfusion and inflammation.
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AIM: To study the preconditioning effect of nitrate medicine on different parts of the heart and its signaling pathway. METHODS: The cells from different parts of the heart (atrium, left ventricle, right ventricle, apex and the whole heart) were isolated and cultured. The cultured cells were treated with hypoxia and reperfusion, hypoxia preconditioning, 1 mmol/L L-arginine preconditioning and 5 mmol/L L-arginine preconditioning, respectively. The cell necrosis rate, cell apoptosis rate, LDH concentration in the medium, the [Ca 2+]i and PKC activity in the cells were determined. RESULTS: The result show that hypoxia and reperfusion increased the necrosis rate and apoptosis rate, enhanced the concentration of LDH in the medium and the [Ca 2+]i overload in the cells (P0.05). After hypoxia preconditioning and L-arginine preconditioning, these indexes decreased (P