Src/Stat3通路在高糖诱导的血管平滑肌细胞增殖及迁移中的作用

目的:探讨Src酪氨酸激酶(Src)/信号转导子和转录激活子3(Stat3)在高糖(HG)诱导的血管平滑肌细胞(VSMCs)增殖和迁移中的作用。方法:首先将VSMC细胞株A7R5与HG(10~40 mmol/L)共同孵育24h,MTT法及EdU染色检测VSMCs增殖,Transwell小室检测VSMCs迁移,Western blot检测p-Src、Src、p-Stat3和Stat3的蛋白水平。q PCR检测Stat3靶基因细胞周期蛋白D1(cyclin D1)、Myc、基质金属蛋白酶2(MMP2)及基质金属蛋白酶9(MMP9)的表达。为了进一步证实Src在高糖诱导VSMCs增殖和迁移中的作用,将HG与Src抑制剂saracatinib(100 nmol/L)共同孵育24 h,观察Src对HG诱导VSMCs增殖、迁移及Stat3激活的影响。结果:HG能浓度依赖性地促进VSMCs的增殖及迁移并激活Src和Stat3,上调Stat3靶基因cyclin D1、Myc、MMP2及MMP9的表达。抑制Src激活可抑制HG诱导的VSMCs增殖及Stat3的激活,同时下调cyclin D1及Myc的表达。结论:Src/Stat3通路可能在HG诱导的VSMCs增殖及迁移中发挥重要作用。     

Curcumin inhibits the survival and metastasis of prostate cancer cells via the Notch‐1 signaling pathway

Prostate cancer is one of the most common malignancies in men, and it urgently demands precise interventions that target the signaling pathways implicated in its initiation, progression, and metastasis. The Notch‐1 signaling pathway is closely associated with the pathophysiology of prostate cancer. This study investigated the antitumor effects and mechanisms of curcumin, which is a well‐known natural compound from curcuminoids, in prostate cancer cells. Viability, proliferation, and migration were analyzed in two prostate cancer cell lines, DU145 and PC3, after curcumin treatment. Whether the Notch‐1 signaling pathway is involved in the antitumor effects of curcumin was examined. Curcumin inhibited the survival and proliferation of PC3 and DU145 cells in a dose‐ and time‐dependent manner and inhibited DU145 migration. Curcumin did not affect the expression of Notch‐1 or its active product NICD, but it did inhibit the expression of MT1‐MMP and MMP2 proteins in DU145 cells. We found that curcumin inhibited the DNA‐binding ability of NICD in DU145 cells. In conclusion, curcumin inhibited the survival and metastasis of prostate cancer cells via the Notch‐1 signaling pathway.     

Influence of endothelial cells on vascular smooth muscle cells phenotype after irradiation: implication in radiation-induced vascular damages

Damage to vessels is one of the most common effects of therapeutic irradiation on normal tissues. We undertook a study in patients treated with preoperative radiotherapy and demonstrated in vivo the importance of proliferation, migration, and fibrogenic phenotype of vascular smooth muscle cells (VSMCs) in radiation-induced vascular damage. These lesions may result from imbalance in the cross talk between endothelial cells (ECs) and VSMCs. Using co-culture models, we examined whether ECs influence proliferation, migration, and fibrogenic phenotype of VSMCs. In the presence of irradiated ECs, proliferation and migration of VSMCs were increased. Moreover, expressions of alpha-smooth muscle actin, connective tissue growth factor, plasminogen activator inhibitor type 1, heat shock protein 27, and collagen type III, alpha 1 were up-regulated in VSMCs exposed to irradiated ECs. Secretion of transforming growth factor (TGF)-beta1 was increased after irradiation of ECs, and irradiated ECs activated the Smad pathway in VSMCs by inducing Smad3/4 nuclear translocation and Smad-dependent promoter activation. Using small interferring RNA targeting Smad3 and a TGFbeta-RII neutralizing antibody, we demonstrate that a TGF-beta1/TGF-beta-RII/Smad3 pathway is involved in the fibrogenic phenotype of VSMCs induced by irradiated ECs. In conclusion, we show the importance of proliferation, migration, and fibrogenic phenotype of VSMCs in patients. Moreover, we demonstrate in vitro that ECs influence these fundamental mechanisms involved in radiation-induced vascular damages.     

E1A激活基因阻遏子蛋白过表达可抑制人血管平滑肌细胞的迁移

背景：成熟动脉中膜血管平滑肌细胞(vascular smooth muscle cells, VSMCs)分化稳态的丧失是血管老化的一个重要原因。 目的：观察E1A激活基因阻遏子(cellular repressor of E1A-stimulated genes,CREG)抑制人血管平滑肌细胞迁移的分子机制。 方法：应用已建立的稳定转染CREG过表达细胞hVSMCs-CREG和CREG表达沉默的hVSMCs-siCREG细胞株通过刮伤实验和Transwell小室细胞移行实验检测细胞迁移能力,通过Western blot检测转染前后细胞中CREG蛋白、基质金属蛋白酶和JNK表达及活化情况,应用JNK和基质金属蛋白酶9抑制剂阻断研究分析上述信号分子表达变化在细胞迁移中的作用。 结果与结论：Western blot结果证实,CREG蛋白表达在hVSMCs-CREG组中增加(P < 0.05),而在hVSMCs-siCREG组中减少(P < 0.05)。刮伤实验和Transwell实验分析结果证实hVSMCs-CREG组细胞较正常对照组细胞迁移能力受抑。相反,hVSMCs-siCREG组细胞迁移能力显著增加(P< 0.05)。Western blot和明胶酶谱分析证实hVSMCs-siCREG组细胞中MMP9活性明显增加(P < 0.05),同时JNK蛋白活化。进一步应用JNK抑制剂阻断研究证实,CREG蛋白表达抑制引起的血管平滑肌细胞迁移能力增加与细胞中基质金属蛋白酶9活性均受到剂量依赖性抑制。结果证实,CREG蛋白表达可抑制JNK-基质金属蛋白酶9信号通路的活化,以此抑制体外培养的人血管平滑肌细胞迁移。     

miR-27a-3p靶向HOXA5基因通过Wnt/β-catenin信号通路调控糖尿病患者创面愈合

目的:研究微小RNA-27a-3p(miR-27a-3p)对糖尿病患者创面愈合的影响及作用机制.方法:采用qPCR和Western blot检测糖尿病患者创面愈合组织中miR-27a-3p、同源异型盒基因A5(HOXA5)mRNA和HOXA5蛋白的表达.使用高糖处理人微血管内皮细胞(HMECs),模拟糖尿病HMECs的...     

Omega-6/omega-3 essential fatty acid ratio in cultured beluga sturgeon

The balance of omega-6/omega-3 fatty acids is an important factor in human health. High omega-6 fatty acid content in the diet along with a high omega-6/omega-3 ratio can lead to the development of many chronic diseases. Conversely, higher levels of omega-3 fatty acids such as eicosapentaenoic acid (C20:5, EPA) and docosahexaenoic acid (C22:6, DHA) and lower omega-6/omega-3 ratio are desirable for human health. We determined the lipid content in beluga flesh which was 6.5?%. Monounsaturated fatty acids were the main class of fatty acids followed by polyunsaturated and saturated fatty acids. The EPA and DHA contents of cultured beluga flesh were lower than those of other cultured sturgeon species, which may be due to the contents of these fatty acids in the diet. The content of omega-6 fatty acids (25.7?%) was higher than omega-3 fatty acids (8.58?%), giving an omega-6/omega-3 ratio of 3.00.     

Effect of docosahexaenoic acid on macrophage functions of rats

Docosahexaenoic acid (DHA) is an omega-3 fatty acid which has been demonstrated to exhibit anti-inflammatory effects. The objective of this study was to determine the effect of DHA on phagocytic and chemotactic activities of peritoneal macrophages obtained from rats. DHA was dissolved in 1 ml of corn oil at dose of 36 mg/kg/day and given via oral gavage for 4 weeks. Control rats received 1 ml/day corn oil as vehicle. At the end of the treatment period, peritoneal macrophages were isolated and chemotactic and phagocytic activities were assayed. Chemotactic and phagocytic activities were reduced in rats fed with DHA. These results demonstrated the effect of DHA in modulating immune activities of rat peritoneal macrophages.     

Arylsulfatase B regulates colonic epithelial cell migration by effects on MMP9 expression and RhoA activation

Arylsulfatase B (ASB; N-acetylgalactosamine-4-sulfatase; 4-sulfatase; ARSB) is the enzyme that removes 4-sulfate groups from N-acetylgalactosamine 4-sulfate, which combines with glucuronate to form the disaccharide unit of chondroitin-4-sulfate (C4S). In this study, we report how variation in expression of ASB affected the migration of human colonic epithelial cells. In the T84 cell line, derived from lung metastasis of malignant colonic epithelial cells, the activity of ASB, as well as steroid sulfatase, arylsulfatase A, and galactose-6-sulfatase, were significantly less than in normal, primary colonic epithelial cells and in the NCM460 cell line which was derived from normal colonocytes. In the T84 cells, matrix metalloproteinase 9 (MMP9), activated RhoA, and cell migration, as well as C4S content, were significantly more than in the NCM460 cells. Silencing and overexpression of ASB had inverse effects on MMP9, activated RhoA, and cell migration, as well as the C4S content, in the NCM460 and T84 cells. When ASB expression was silenced by siRNA in the NCM460 cells, MMP9 secretion increased to over 3 times the basal level, activated RhoA increased ~85%, and cell migration increased ~52%. Following overexpression of ASB, MMP9 declined 51%, activated RhoA declined ~51%, and cell migration decreased ~37%. These findings demonstrate marked effects of ASB expression on the migratory activity of colonic epithelial cells, activated RhoA, and MMP9, and suggest a potential vital role of ASB, due to its impact on chondroitin sulfation, on determination of the invasive phenotype of colonic epithelial cells.     

CGRP修饰大鼠MSCs对血管平滑肌细胞增殖及表型转化的影响

 目的：探讨降钙素基因相关肽（calcitonin gene-related peptide, CGRP）修饰的大鼠间充质干细胞（mesenchymal stem cells, MSCs）在体外对大鼠血管平滑肌细胞（vascular smooth muscle cells, VSMCs）增殖和表型转化的影响及其机制。方法：分离、培养及鉴定大鼠MSCs和VSMCs。CGRP重组慢病毒（Lv-CGRP-EGFP）转染MSCs后,real-time PCR和ELISA法检测MSCs中CGRP的表达。MSCs-CGRP与VSMCs共培养后MTT、台盼蓝染色及划痕实验评价VSMCs增殖、迁移能力及细胞存活率。Western blotting法检测VSMCs中α-平滑肌肌动蛋白(alpha-smooth muscle actin, α-SMA)和骨桥蛋白(osteopontin, OPN)的表达水平。结果：与MSCs组和空载病毒转染组（MSCs-EGFP）比较,CGRP修饰的MSCs（MSCs-CGRP组）中CGRP的mRNA和蛋白表达水平增高（均P<0.01）。MTT法和划痕实验显示,与MSCs组和MSCs-EGFP组比较,MSCs-CGRP组中VSMCs的增殖和迁移能力明显减弱（P<0.05）,而且台盼蓝染色显示,各组细胞存活率均大于90%。Western blotting结果显示,与MSCs-CGRP共培养的VSMCs中α-SMA较MSCs组和MSCs-EGFP组表达增加,OPN的表达减少（均P<0.05）。结论：CGRP修饰的MSCs能分泌CGRP蛋白,并且能抑制VSMCs的增殖和迁移,其机制可能通过抑制VSMCs的表型从收缩表型向合成表型转化有关。     

Platelet-derived growth factor and transforming growth factor-β modulate the expression of matrix metalloproteinases and migratory function of human airway smooth muscle cells

Background Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) have been suggested to be involved in the pathogenesis of asthma. Their expression in airway smooth muscle (ASM) cells could be involved in collagen turnover and migration of these cells and thus may contribute to airway remodelling.
Objective To examine the effect of pro-fibrotic growth factors TGF-β and platelet-derived growth factor (PDGF) on the expression of MMPs/TIMPs in cultured human ASM cells and to examine the role of MMP in the migration of ASM cells.
Methods ASM cells were stimulated with TGF-β and/or PDGF. Expression and activity of MMP-1, MMP-2, MMP-3, TIMP-1 and TIMP-2 were evaluated by quantitative RT-PCR, Western blot and zymography. Modified Boyden-chamber migration assay was performed to investigate the effect of secreted MMP-3 and TIMP-1 on ASM-cell migration.
Results PDGF strongly up-regulated the expression of MMP-1 at mRNA and protein levels. PDGF, when combined with TGF-β, caused synergistic up-regulation of MMP-3. TIMP-1 was additively up-regulated by TGF-β and PDGF. These growth factors had no effect on the expression of MMP-2 and TIMP-2. U0126, an extracellular signal-regulated kinase (ERK) pathway inhibitor, inhibited the up-regulation of MMP-1 by PDGF. The synergistic/additive up-regulation of MMP-3 and TIMP-1 was inhibited by U0126 and SB431542, a Smad pathway inhibitor. Supernatant from ASM cells in which MMP-3 production was knocked down by RNA interference showed a decreased migratory effect on ASM cells, whereas supernatant from cells with suppressed TIMP-1 expression resulted in increased migration.
Conclusion Our results suggest that PDGF with/without TGF-β could facilitate migration of ASM cells by modification of MMP–TIMP balance through the ERK pathway.     

Pilot study of omega-3 fatty acid supplements in sickle cell disease

In a previous retrospective study, it was observed that the greater the amounts of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the blood, the lesser the number of complications of sickle cell disease (SCD) and the higher the steady state haemoglobin level. SCD causes ischaemia-reperfusion injury and inflammation; which can be ameliorated by a metabolite of DHA that down-regulates expression of pro-inflammatory genes. The objectives of this prospective pilot study were to evaluate the effects of DHA and EPA supplements in SCD, and test the hypothesis that these effects are mediated partly by reducing inflammation. Oral DHA and EPA supplements were given to 16 SCD patients for 6 months. We then compared pre- and post-supplementation values of number of crisis, steady state Hb, plasma unconjugated bilirubin and three indices of inflammation: plasma interleukin-6, blood neutrophil and platelet counts. There was a significant reduction in the plasma level of unconjugated bilirubin, and the number of sickle cell crisis; but not in the markers of inflammation. The pilot data suggest that DHA and EPA supplements reduce the number of crisis and steady state haemolysis in SCD; but provide no evidence that these effects are mediated by reducing inflammation.     

Cardiac physiology and clinical efficacy of dietary fish oil clarified through cellular mechanisms of omega-3 polyunsaturated fatty acids

Reduced cardiac mortality and morbidity have long been observed in association with omega-3 long chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish consumption, without clear physiological explanation. This review seeks to identify mechanisms of action based on evidence: of physiological effects, active components and effective intakes. Fish oil pleiotropic effects reveal actions that are either intrinsic: effects on cardiac function dependent upon membrane incorporation; or extrinsic: indirect cardiac effects through vascular disease. Extrinsic actions require EPA + DHA doses >3 g/day. Intrinsic effects derive from usual dietary intakes, <1 g/day and include improved myocardial oxygen efficiency, heart rate, nutritional preconditioning against ischaemic injury, arrhythmias and heart failure. Myocardial Na⁺ and K⁺ currents are non-selectively modulated by omega-3 and omega-6 PUFA to stabilise cells in vitro, but not by fish oil-induced membrane change. In contrast, cellular Ca²⁺ overload involved in ischaemic injury, arrhythmia and spontaneous pacemaker activity are modulated by both dietary fish oil and in vitro omega-3 LC-PUFA. A potential linking role of bioactive epoxy and hydroxy PUFA derivatives requires investigation. Omega-3 DHA predominates over EPA in population intake, is preferentially incorporated into myocardium and is selectively active in heart rate and arrhythmia modulation, but EPA predominates in clinical trials. Myocardial selectivity for DHA and independent intrinsic and extrinsic physiological mechanisms underpinning diverse clinical endpoints can explain some contradictory outcomes of clinical trials. Intrinsic modulation of intracellular Ca²⁺ handling provides a unifying physiologically plausible basis for intrinsic fish oil actions and insight to nutritional optimisation of cardiac function.     

Impaired migration, integrin function, and actin cytoskeletal organization in dermal fibroblasts from a subset of aged human donors

Deficits in the motility of fibroblasts contribute to age-related impairment of wound healing. We analyzed 'young' fibroblasts from four healthy donors 22-30 years old and 'aged' fibroblasts from six healthy donors 81-92 years old for migratory ability on type I collagen, secretion of matrix metalloproteases (MMPs), attachment to matrices and, expression and function of integrin alpha2beta1. Cells from each donor were analyzed separately in each experiment. Whereas migration of young fibroblasts was uniformly robust, three aged lines migrated well and three migrated poorly. Synthesis of MMP1 and TIMP1, but not MMP2 or MMP9, was increased in the aged fibroblasts relative to the young fibroblast lines irrespective of their motility. All lines of young and aged fibroblasts attached to plastic or collagen with similar efficiency. Although young and aged fibroblasts expressed comparable levels of the alpha2 integrin; the lines of aged fibroblasts that were poor migrators exhibited a significant reduction in alpha2beta1 function relative to fibroblasts with normal migratory capacities. Moreover, the lines of aged fibroblasts that exhibited poor migration demonstrated a disordered actin cytoskeleton and a reduced ability to contract collagen gels. In conclusion, aged fibroblasts, unlike young fibroblasts, displayed variable migratory capacities. Deficient migration by specific lines of aged fibroblasts was not related to the capacity to attach, express alpha2 integrin, or secrete MMPs and TIMP1, but was characterized by disorganized cytoskeletal actin and reduced alpha2beta1 function.     

Gallic acid modulates phenotypic behavior and gene expression in oral squamous cell carcinoma cells by interfering with leptin pathway

Gallic acid is a polyphenolic compost appointed to interfere with neoplastic cells behavior. Evidence suggests an important role of leptin in carcinogenesis pathways, inducing a proliferative phenotype. We investigated the potential of gallic acid to modulate leptin-induced cell proliferation and migration of oral squamous cell carcinoma cell lines. The gallic acid effect on leptin secretion by oral squamous cell carcinoma cells, as well as the underlying molecular mechanisms, was also assessed. For this, we performed proliferation, migration, immunocytochemical and qPCR assays. The expression levels of cell migration-related genes (MMP2, MMP9, Col1A1, and E-cadherin), angiogenesis (HIF-1α, mir210), leptin signaling (LepR, p44/42 MAPK), apoptosis (casp-3), and secreted leptin levels by oral squamous cell carcinoma cells were also measured. Gallic acid decreased proliferation and migration of leptin-treated oral squamous cell carcinoma cells, and reduced mRNA expression of MMP2, MMP9, Col1A1, mir210, but did not change HIF-1α. Gallic acid decreased levels of leptin secreted by oral squamous cell carcinoma cells, accordingly with downregulation of p44/42 MAPK expression. Thus, gallic acid appears to break down neoplastic phenotype of oral squamous cell carcinoma cells by interfering with leptin pathway.     

Docosahexaenoic acid (DHA) induces apoptosis in human hepatocellular carcinoma cells

The docosahexaenoic (DHA), a ω-3 fatty acid, could play a beneficial inhibition of the incidence and progress of a series of human diseases including cancer. It has been report that DHA is involved in cell apoptosis. Recent studies show that the signal transduction pathway links with bcl-2, bax, caspase-3 and MMP-9 molecules. Therefore, we tested the relationship between DHA and cell apoptosis in human hepatocellular carcinoma cells (Bel-7402 cells). We show here that DHA induces Bel-7402 cells apoptosis after pre-treating cells with DHA. DHA down-regulates the protein expression of Bcl-2 and Bim mRNA level, and up-regulates caspase-3 activity and Bax expression level. We also found that DHA inhibits Bel-7402 cells migration. Basic on our studies, DHA may play a role in tumor invasion and survival.     

Dietary enrichment with omega-3 polyunsaturated fatty acids reverses age-related decreases in the GluR2 and NR2B glutamate receptor subunits in rat forebrain

Ageing is associated with a decrease in the brain content of omega-3 polyunsaturated fatty acids (PUFA), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and with decreased neuroplasticity. The glutamate receptor subunits GluR2 and NR2B play a significant role in forebrain synaptic plasticity. We investigated GluR2 and NR2B in the aged prefrontal cortex, hippocampus and striatum, and tested if treatment with a preparation containing EPA and DHA can reverse age-related changes. The study compared adult and old (3-4 and 24-26 month) rats, and the latter were fed a standard diet or a diet supplemented for 12 weeks with omega-3 PUFA at 270mg/kg/day (ratio EPA to DHA 1.5:1). Ageing was associated with decreases in the GluR2 and NR2B subunits in all structures. These decreases were fully reversed by omega-3 PUFA supplementation. Age-related changes in the phospholipid PUFA content were also seen. Decreases in DHA were mostly corrected by supplementation. This study supports the neuroprotective effect of omega-3 fatty acids in brain ageing, and illustrates specific mechanisms underlying this effect.     

Blockade of integrin beta3-FAK signaling pathway activated by osteopontin inhibits neointimal formation after balloon injury.

BACKGROUND: Osteopontin (OPN) promotes the migration and adhesion of vascular smooth muscle cells (VSMCs) through cell surface receptor, integrin beta3. In order to elucidate the signaling pathway by which OPN is involved in neointimal formation, we focused on integrin beta3-focal adhesion kinase (FAK) upon VSMC migration. METHODS: The integrin beta3 and FAK expression in VSMC and in neointima was detected by Western blot and immunohistochemistry staining. FAK phosphorylation induced by OPN was verified using a linear OPN 13 peptide containing RGD motif and anti-OPN antibody. The role of integrin beta3-FAK pathway in VSMC adhesion and migration induced with OPN was tested by the overexpression of FAK-related nonkinase and integrin beta3 cytoplasmic domain. RESULTS: The results showed that OPN increased integrin beta3 expression and induced rapid and transient FAK phosphorylation. Inhibition of the phosphorylation of FAK significantly suppressed VSMC migration induced by OPN. Similarly, blockade of the interaction of integrin beta3 with OPN inhibited VSMC adhesion induced by OPN. The experiment, in vivo, demonstrated that OPN expression level was consistent with neointimal thickening. Administration of anti-OPN antibody for blocking OPN function suppressed integrin beta3 and FAK expression induced by balloon injury, and neointimal thickening was inhibited. CONCLUSIONS: These data indicate that integrin beta3-FAK signaling modulates OPN-induced VSMC migration during neointimal formation.