Glycosylation-independent binding to extracellular domains 11-13 of mannose-6-phosphate/insulin-like growth factor-2 receptor mediates the effects of soluble CREG on the phenotypic proliferation of vascular smooth muscle cells

Background The present study aimed to investigate the detailed mode and specific sites for their binding as well as the functional relevance of this binding in the phenotypic proliferation of vascular smooth muscle cells(SMCs). Methods CREG knocked-down SMCs were employed to evaluate the biological activity of wtCREG and mCREG.Expressions of SMC differentiation markers SM myosin heavy chain(SM-MHC),SM-actin,heavy caldesmon and myocardin were determined by Western blotting using specific antibodies. Cellular growth of SMCs was assessed by bromide dewuridine (BrdU) incorporation and cell cycle analysis on fluorescence-activated cell sorting(FACS).A solid-phase binding assay was used to study the binding of CREG to extracellular domains of M6P/IGF2R.The cellular co-localization of the two recombinant CREGs with M6P/IGF2R was detected on SMC surface by immunoprecipitation and immunofluorescence analysis.Results The molecular weight of wtCREG was around 30 kD while that of the mCREG was～25 kD.Treatment of wtCREG with PNGase F reduced its molecular weight from～30 kD to～25 kD,whereas PNGase F treatment had no effect on the molecular weight of mCREG.Both wtCREG and mCREG proteins enhanced SMC differentiation,inhibited BrdU incorporation,and arrested cell cycle progression when added to the culture medium.In CREG knocked-down SMCs,the amount of CREG detected by immunoblotting in M6P/IGF2R immunoprecipitates was significantly reduced when compared to normal cells.Both recombinant CREGs co-immunoprecipitated with M6P/IGF2R, although slightly reduced amount of the mutant CREG was detected in M6P/IGF2R immunoprecipitates.Immunostaining revealed that His-tagged CREGs co-localized with IGF2R on the cell surface in a glycosylation-independent manner.In vitro binding assay showed that CREGs bound to M6P/ IGF2R extracellular domains 7-10 and 11-13 in a glycosylation -dependent and -independent manner,respectively.Further blocking experiments using soluble M6P/IGF2R fragments and M6P/IGF2R neutralizing antibody indicated tha     

RNAi下调MAGE-A9表达抑制非小细胞肺癌细胞转移潜能的实验研究

目的探讨RNAi技术沉默MAGE-A9表达对非小细胞肺癌细胞转移潜能的影响。方法采用Western blot法检测非小细胞肺癌细胞系中MAGE-A9蛋白表达。在H1299细胞中沉默MAGE-A9表达,Western blot和Transwell实验分别检测H1299细胞中基质金属蛋白酶2(MMP-2)、基质金属蛋白酶9(MMP-9)和核转录因子κB p65(NF-κB p65)蛋白表达及细胞迁移和侵袭数变化。结果与HBE人正常支气管上皮细胞相比,人非小细胞肺癌细胞系H1299、H460、95-D中MAGE-A9蛋白表达上调(P0.05),其中H1299细胞中MAGE-A9蛋白表达水平最高,选取H1299细胞用于后续实验。Western blot和Transwell实验结果显示,将pSUPER-shRNA MAGE-A9重组质粒转染至H1299细胞后,细胞中MMP-2、MMP-9和NF-κB p65蛋白表达下调(P0.05),细胞迁移和侵袭数减少(P0.05)。结论 MAGE-A9在人非小细胞肺癌细胞中呈高表达,沉默MAGE-A9可抑制H1299细胞迁移和侵袭,其机制可能与MMP-2、MMP-9及NF-κB信号通路有关。     

氧化型低密度脂蛋白对大鼠血管平滑肌细胞基质金属蛋白酶-2和9表达的影响

为探讨氧化型低密度脂蛋白致动脉粥样硬化的作用是否与基质金属蛋白酶表达活性改变有关,应用Northern blot、Dot blot、Westorn blott和明胶酶图分析方法观察氧化型低密度脂蛋白对体外培养的大鼠血管平滑肌细胞表达基质金属蛋白酶－2和9的影响。结果显示,10mg/L氧化型低密度脂蛋白作用于血管平滑骨细胞24h,可明显增强基质金属蛋白酶－2和9mRNA的表达、蛋白分泌和酶的活性,高浓度的氧化型低密度脂蛋白对基质金属蛋白酶－2和9表达的影响不同,氧化型低密度脂蛋白浓度为50mg／L时,基质金属蛋白酶－9表达活性仍然高于对照细胞,但于10mg／L氧化型低密度脂蛋白的作用强度无显著差别;相同条件下,基质金属蛋白酶－2的基因表达和蛋白分泌明显降低。以上结果提示,氧化型低密度脂蛋白可诱导血管平滑肌细胞基质金属蛋白酶－2和9的表达,并可促进细胞外基质降解。     

RNA干扰沉默基质交感分子1基因后对血管平滑肌细胞周期的影响

目的探讨RNA干扰技术沉默基质交感分子1基因后对血管平滑肌细胞周期的影响。方法原代培养血管平滑肌细胞,用构建好的大鼠基质交感分子1干扰腺病毒载体和人重组基质交感分子1腺病毒载体进行转染,Western blot检测细胞基质交感分子1、p21和pRb表达,流式细胞仪测定细胞周期。结果大鼠基质交感分子1干扰腺病毒载体转染后48h细胞基质交感分子1表达与转染对照腺病毒载体比较明显降低(P<0.05),处于G0/G1细胞比例也明显增多(P<0.05),p21表达上调,pRb表达下调(P<0.05);人重组基质交感分子1腺病毒载体共转染后48h细胞基质交感分子1表达恢复到正常水平;G0/M细胞比例、p21和pRb表达恢复到正常水平。结论基质交感分子1基因沉默上调p21表达,下调pRb表达,抑制细胞进入S期,进而参与对血管平滑肌细胞增殖的调控。     

血小板源生长因子对大鼠血管平滑肌细胞表达基质金属蛋白酶2的影响

目的研究血小板源生长因子对血管平滑肌细胞迁移的影响和细胞产生基质金属蛋白酶2的变化。方法体外培养的血管平滑肌细胞经血小板源生长因子处理0 min、20 min和6 h后进行如下检测:迁移实验观察细胞在盖玻片上的迁移情况;明胶酶谱检测血管平滑肌细胞分泌基质金属蛋白酶2活性;基因芯片和逆转录-聚合酶链反应技术检测血管平滑肌细胞表达基质金属蛋白酶2 mRNA的变化。结果细胞迁移实验显示随着作用时间的延长,血小板源生长因子明显促进细胞的迁移,血小板源生长因子处理20 min和6 h后迁移距离(分别为4.9±0.5、7.1±1.2μm)是对照组(2.3±0.15μm)的2.13倍和3.09倍,差异有显著性(P<0.05);明胶酶谱测定表明:血小板源生长因子显著提高血管平滑肌细胞分泌的基质金属蛋白酶2的活性,作用20 min与6 h后(分别为480.7±27.3和851.5±56.4)是对照组(296.7±15.8)的1.62倍和2.87倍(P<0.01);血小板源生长因子对血管平滑肌细胞表达基质金属蛋白酶2有明显的诱导作用,作用20 min与6 h后的表达(分别为0.54±0.09和0.77±0.04)是对照组(0.3...     

异丙肾上腺素诱导慢性心力衰竭大鼠模型的建立

Background The CREG is an important lysosomal protein involved in a variety of cellular functions including promoting cell differentiation,sustaining mature homeostasis, and antagonizing apoptosis.Deficiency of CREG in cell and tissue results in a pathologic apoptosis.The present study aimed to elucidate the mechanism of CREG regulation apoptosis.Methods We firstly generated stable NIH3T3 fibroblasts by transfection of pDS_shCREGs vectors.Furthermore, PI-Annexin V and TUNEL staining were used to identify that CREG knockdown promoted the cell apoptosis in NIH3T3 fibroblasts.Western blotting and immunofluorescence staining was used to identify the expression and localization of M6P/ IGF2R and cathepsin L in cytoplasm.Results pDS_shCREGs vector transfection produced an approximately 80%decrease in CREG levels both in the lysate and in the media.The expression and localization of M6P/IGF2R and cathepsin L in cytoplasma changed obviously associated with down-regulated of CREG.In addition,the retention and secretion of cathepsin L enhanced significantly.Using the specific inhibitor or siRNA to block cathepsin L activation attenuated the apoptosis mediated by CREG downregulation.Conclusions Our findings indicated that inhibition of CREG expression in NIH3T3 fibroblasts leads to impaired cathepsin L sorting function mediated by M6P/IGF2R and subsequently promotes pathological cell apoptosis.     

辣椒素对高盐致大鼠血管平滑肌细胞增殖的抑制作用

目的研究辣椒素对高盐诱导的大鼠血管平滑肌细胞(VSMC)增殖的抑制作用。方法组织贴壁法培养原代大鼠血管平滑肌细胞,根据MTT结果绘制大鼠血管平滑肌细胞的生长曲线,大鼠血管平滑肌细胞传至第4代去血清同步化24 h,不同浓度辣椒素(0.01μmol/L、0.1μmol/L、1μmol/L、10μmol/L、100μmol/L)进行高盐培养72 h,MTT比色法检测大鼠血管平滑肌细胞增殖情况,选取抑制血管平滑肌细胞增殖的辣椒素浓度进行后续实验。CCK-8检测渗透压对大鼠血管平滑肌细胞增殖的影响,流式细胞仪分析细胞增殖周期,免疫荧光染色法和Western blot检测增殖细胞核抗原(PCNA)的表达,实时荧光定量PCR检测瞬时受体电位家族香草醛1型受体(TRPV1)mRNA的表达,Western blot检测瞬时受体电位家族香草醛1型受体的蛋白表达。结果 MTT结果显示,辣椒素浓度为10μmol/L时大鼠血管平滑肌细胞增殖开始受抑制,100μmol/L时抑制作用增强(P0.05),选取10μmol/L辣椒素进行后续实验。CCK-8结果显示,高盐组细胞明显增殖,而甘露醇组、正常组和高盐+辣椒素组无差异。流式细胞仪测得高盐组G0/G1、G2/M期细胞比例减少(P0.05),S期细胞比例增多(P0.05);与高盐组比较,高盐+辣椒素组G0/G1、G2/M期细胞比例增加(P0.05),S期细胞比例下降(P0.05)。免疫荧光及Western blot结果显示,高盐组增殖细胞核抗原阳性细胞核增多,蛋白表达增加(P0.05),而高盐+辣椒素组增殖细胞核抗原阳性细胞核减少,蛋白表达减少(P0.05)。实时荧光定量PCR和Western blot结果显示高盐组瞬时受体电位家族香草醛1型受体mRNA及蛋白表达减少(P0.05),辣椒素组则增加(P0.05)。结论辣椒素可抑制高盐所致的大鼠血管平滑肌细胞增殖,其作用机制可能与激活瞬时受体电位家族香草醛1型受体表达有关。     

尼古丁对人A549细胞增殖、侵袭和迁移能力的影响

目的 观察烟草烟雾中的主要有害成分尼古丁对人A549细胞增殖、迁移与侵袭能力的影响,探讨尼古丁致病的可能机制.方法 以一定浓度尼古丁刺激体外培养的人A549细胞,应用CCK-8法、Transwell法和细胞划痕实验分别检测A549细胞的增殖、侵袭及迁移能力.Western blot检测α7烟碱型乙酰胆碱受体(α7 nAChR)、血管内皮生长因子(VEGF)和基质金属蛋白酶2(MMP-2)蛋白的表达.结果 与空白对照组比较,10-6 mol/L尼古丁处理A549细胞后,促进人A549细胞增殖(t=7.920,P<0.05);使穿过基质胶的细胞数增多,侵袭能力增强(t=5.298,P<0.05);使细胞迁移率增加,迁移能力增强(P<0.05).与空白对照组比较,10-6 M尼古丁处理A549细胞24 h后,α7 nAChR、VEGF和MMP-2蛋白表达上调,差异有统计学意义(t值分别为5.800、4.074、6.851,P值均<0.05).结论 尼古丁通过其特异性受体α7 nAChR可增强人A549细胞的增殖、侵袭和迁移能力,其机制可能与VEGF和MMP-2蛋白表达上调有关.     

槲寄生多糖调控胃癌细胞增殖、迁移和侵袭的机制研究

背景胃癌(gastric cancer, GC)是严重危害人体健康的恶性肿瘤,其发病率和死亡率分别占世界恶性肿瘤的第5位和第3位.中医药治疗能够减轻患者病痛,改善术后复发,槲寄生多糖(viscum coloratum polysaccharide,VCP)是槲寄生抗肿瘤的主要活性成分之一,能够抑制癌细胞增殖并诱导凋亡.目的观察VCP对胃癌细胞增殖、迁移和侵袭能力的影响并探讨其潜在作用机制.方法以不同浓度(20μg/mL、40μg/mL、60μg/mL、80μg/mL、100μg/mL)VCP干预SGC-7901人GC细胞48h,MTT法检测细胞活力.以100μg/mLVCP干预SGC-7901细胞, Western blot、Transwell小室分别检测细胞中周期蛋白依赖性蛋白激酶4(cyclin-dependent proteinkinases4,CDK4)、基质金属蛋白酶2(matrix metalloproteinase-2,MMP-2)、基质金属蛋白酶9(matrix metalloproteinase-9, MMP-9)和核转录因子κB p65蛋白表达及细胞迁移和侵袭能力变化.结果不同浓度VCP均可抑制SGC-7901细胞活力(P0.05),呈浓度依赖性. Western blot和Transwell实验结果表明:与对照组相比, 100μg/mLVCP处理的SGC-7901细胞中CDK4、MMP-2、MMP-9、核转录因子-κB(nuclearfactorkappabeta,NF-κB)p65蛋白表达下调(P 0.05),同时视野内迁移和侵袭细胞数明显减少(P 0.05).结论 VCP对SGC-7901人GC细胞增殖、迁移和侵袭具有抑制作用,其机制可能与NF-κB信号通路及CDK4、MMP-2和MMP-9蛋白有关.     

活化淋巴细胞诱导人血管平滑肌细胞基质金属蛋白酶表达

为探讨活化的淋巴细胞直接接触对血管平滑肌细胞基质金属蛋白酶表达的影响 ,用乙酸肉豆蔻佛波醇活化并经 1%多聚甲醛固定的人外周血淋巴细胞 ,与培养的人类胚胎血管平滑肌细胞共同孵育 ,用聚丙烯酰胺凝胶电泳法测定细胞培养上清液中基质金属蛋白酶的活性。结果发现 ,基础状态下的体外培养人血管平滑肌细胞合成基质金属蛋白酶 2的酶原形式 ,有少量基质金属蛋白酶 2的活性形式存在。经佛波醇活化淋巴细胞组上清液中可检测到基质金属蛋白酶 1、基质金属蛋白酶 3和基质金属蛋白酶 9活性 ,并且基质金属蛋白酶 2活性形式较对照组增加 198%± 2 7% (P <0 .0 1) ,未经佛波醇活化的淋巴细胞不影响血管平滑肌细胞基质金属蛋白酶的合成和分泌。以上结果提示 ,活化固定的淋巴细胞可以通过细胞直接接触诱导血管平滑肌细胞基质金属蛋白酶表达增加及活化 ,在动脉粥样硬化的斑块破裂过程中可能起重要作用     

Research and Evaluation of the Influence of the Construction of the Gate and the Influence of the Piston Velocity on the Distribution of Gases into the Volume of the Casting

Distribution of gasses to the cast volume and volume of pores can be maintained within the acceptable limits by means of correct setting of technological parameters of casting and by selection of suitable structure and gating system arrangement. The main idea of this paper solves the issue of suitability of die casting adjustment—i.e., change of technological parameters or change of structural solution of the gating system—with regards to inner soundness of casts produced in die casting process. Parameters which were compared included height of a gate and velocity of a piston. The melt velocity in the gate was used as a correlating factor between the gate height and piston velocity. The evaluated parameter was gas entrapment in the cast at the end of the filling phase of die casting cycle and at the same time percentage of porosity in the samples taken from the main runner. On the basis of the performed experiments it was proved that the change of technological parameters, particularly of pressing velocity of the piston, directly influences distribution of gasses to the cast volume.     

县级以下综合医疗机构医务人员对现代结控知识的认识现状调查

目的本文旨在了解医务人员现代结控知识掌握的现状及培训效果?方法于培训前后进行问卷调查,内容包括:病例发现?结核病诊断及化疗?结果培训前疫情报告和转诊,回答正确者占75.2%?71.7%;对临床表现?查痰和诊断依据,回答正确者占83.5%?42.5%?40.8%;抗痨药物?用药方法?化疗原则?短化方案?短化疗程?治愈标准六项,回答正确者占58%?14.4%?20.8%?9.2%?17%?24.3%?培训后再次调查发现,90%以上医务人员对现代结控基本知识已掌握?结论各级医务人员现代结控知识是很贫乏的,因此,对其进行系统培训是极为必要的,此项工作省时?省力?投入少,可收到事半功倍的效果。     

Preservation of the pylorus and resection of the head of the pancreas

The historical evolution of the pylorus-preservation resection of the head of the pancreas is traced from the first resections early in this century to relative standardization of the operation, to a lowering of the operative mortality, and to an interest in improving nutritional status after resection. There are many theoretical advantages for the function of the upper gastrointestinal tract after pylorus and gastric preservation, such as maintenance of gastric capacitance and equilibration of osmotic pressure in gastric digestants, foodstuff digestion and absorption, and bowel motility. After the pylorus-preserving resection, gastric emptying is normal, pyloric function to prevent duodenal reflux is often normal, and gastric acids and serum levels of duodenal hormones are at normal levels, whereas after standard pancreatoduodenectomy, all of these are often abnormal. No prospective blinded studies have been published comparing nutritional values after the two operative procedures, but evidence is presented of a satisfactory result with regard to gastric capacitance, body weight gain, and lack of postgastrectomy symptoms. An undoubted advantage of the pylorus-preserving feature is a simplification of the operation. These gains are achieved without increase in operative mortality, without increase in the incidence of jejunal ulcer, and without theoretical or actual decrease in value of the procedure as a cancer operation, except in patients with duodenal carcinoma proximal to the ampulla of Vater.     

Preservation of the pylorus in resection of the head of the pancreas

Pylorus preservation has been advocated to decrease the morbidity associated with the classical or standard pancreaticoduodenectomy. The proposed advantages are decreased incidence of peptic ulceration, dumping syndrome, and nutritional problems. However, after an initial period of enthusiasm for the procedure, it is now being found that marginal ulceration at the duodenojejunal anastomosis is encountered with increasing frequency. Delay in gastric emptying occurs frequently, with an overall incidence of 30%. With the availability of better pancreatic enzyme supplements, the current incidence of nutritional problems and weight loss after the standard Whipple procedure is unknown. Whether there is a difference in long-term survival after the two procedures performed for adenocarcinoma of the head of the pancreas is still debatable. A controlled trial is needed to answer many of these questions, and pylorus-preserving pancreaticoduodenectomy should be used cautiously until further data become available.