高血磷对慢性肾衰竭大鼠血管钙化的影响

目的 研究高血磷对慢性肾衰竭大鼠血管钙化的影响。 方法 44只Wistar雄性大鼠分别行5/6肾切除（n=24，模型组）或假手术（n=20，对照组），39只大鼠术后4周开始给予高磷或低磷饮食10周。动物分4组：模型组+高磷饮食(CHP)，模型组+低磷饮食(CLP)，对照组+高磷饮食(NHP)，对照组+低磷饮食(NLP)。高磷饮食配方：磷（P）1.2%, 钙（Ca）1.6%，维生素D 1 IU/kg；低磷饮食配方：P 0.2%, Ca 0.5%，维生素D 1 IU/kg。特定饮食开始（基线）和结束时称体质量；检测Scr、血P、血Ca、1,25(OH)2D3、全段甲状旁腺激素（iPTH）。特定饮食结束时处死大鼠，取胸主动脉组织，采用Von Kossa染色和钙含量测定判断血管钙化程度，同时检测核心结合因子α1（Cbfα-1）mRNA的表达。 结果 术后第4周特定饮食开始时，模型组大鼠Scr水平显著高于对照组大鼠 [（94.4±17.6）比（36.4±0.6）μmol/L，P < 0.05]，余各项指标组间差异无统计学意义。特定饮食10周时，4组间体质量差异无统计学意义；各组各时间点血Ca水平差异均无统计学意义；血1,25(OH)2D3水平除了在NLP组显著增高外，余3组间差异均无统计学意义；CHP组血P和iPTH水平显著增高，出现严重血管钙化、程度3～4级；胸主动脉钙含量明显增高，同时Cbfa-1 mRNA表达显著上调。血P水平对胸主动脉钙含量的影响比iPTH水平更强（β ＝ 0.832>0.267）。血P水平与胸主动脉钙含量、Cbfα-1 mRNA表达量呈直线正相关（r = 0.672～0.73，P < 0.05）。 结论 高血磷是导致慢性肾衰竭大鼠血管钙化的重要因素。 Cbfα-1的表达上调可能是其导致血管钙化的机制之一。     

SET8介导AKT信号通路在调控高磷诱导的血管平滑肌细胞钙化中的作用

目的 探讨赖氨酸甲基转移酶SET8介导AKT信号通路在调控高磷诱导的血管平滑肌细胞(vascular smooth muscle cells, VSMCs)钙化中的作用及机制。方法 (1)选取雄性SD大鼠进行体内实验并随机分为假手术组和慢性肾衰竭血管钙化组。取胸主动脉,采用von Kossa染色检测钙化情况;免疫组化法检测SET8和Caspase-3表达情况。(2)体外实验进行原代VSMCs培养,将细胞随机分为正常组和高磷组(10 mmol/L β-甘油磷酸)。采用邻甲酚酞络合酮比色法及茜素红染色检测细胞钙化情况;流式细胞法检测细胞凋亡情况;RT-PCR和Western印迹法检测SET8、AKT和Caspase-3的表达。(3)为进一步验证SET8在VSMCs凋亡中的作用,采用脂质体转染法,分3组:SET8-短发夹RNA(shRNA)组、空质粒组和正常对照组。采用邻甲酚酞络合酮比色法及茜素红染色检测细胞钙化情况;流式细胞法检测细胞凋亡情况;RT-PCR和Western印迹法检测SET8、AKT、Caspase-3的表达。结果 (1)体内实验中,慢性肾衰竭血管钙化组的血管钙盐沉积量明显高于假手术组(P<0.05);免疫组化结果提示,与假手术组相比,血管钙化组SET8表达明显降低,Caspase-3表达明显升高(均P<0.05);相关分析显示,血管组织SET8表达水平与钙含量、Caspase-3表达呈负相关(r=-0.948,P<0.01;r=-0.961,P<0.01)。(2)体外实验中,高磷组钙盐沉积明显高于正常组(P<0.05);流式细胞术检测结果显示,高磷组VSMCs的凋亡率明显高于正常组(P<0.05);RT-PCR和Western印迹显示,与正常组相比,高磷组SET8和AKT的mRNA和蛋白表达下降,Caspase-3的mRNA和蛋白表达升高(均P<0.05)。(3)干扰SET8基因表达后,VSMCs钙化及凋亡率明显增加,AKT的mRNA和蛋白表达下降,Caspase-3的mRNA和蛋白表达升高(均P<0.05)。结论 SET8可以抑制血管钙化,其机制之一可能为通过促进AKT活化,抑制Caspase-3的表达,从而抑制VSMCs凋亡,进而参与调控高磷诱导的血管平滑肌细胞钙化。     

帕米膦酸钠对高磷诱发大鼠血管平滑肌细胞钙化的影响

目的 观察高磷对大鼠血管平滑肌细胞（RVSMC）钙化的影响,探讨帕米膦酸钠对RVSMC钙化的保护作用及相关机制。 方法 培养RVSMC细胞融合后,实验分为3组：正常磷对照组（Pi 1.4 mmol/L）、高磷组（Pi 4.5 mmol/L）、不同浓度帕米膦酸钠处理组（Pi 4.5 mmol/L+帕米膦酸钠10-5、10-6、10-7 mol/L）。甲O-酚酞络合酮吸光光度法测定细胞外基质钙含量。BCA法测定蛋白含量,用蛋白含量标化钙含量,同时以von Kossa染色半定量钙化情况。Western印迹检测不同组细胞的转录因子核心结合因子α1（cbfα-1）、骨钙素的表达量。 结果 培养3 d后,与高磷组相比,帕米膦酸钠干预组细胞外基质钙含量均显著减少（均P < 0.05）;von Kossa染色显示帕米膦酸钠干预组钙质沉积（黑色颗粒）亦显著减少。Western印迹显示,培养3 d后帕米膦酸钠处理组cbfα-1、骨钙素的表达量均较高磷组显著减少（均P < 0．05）。 结论 帕米膦酸钠对高磷诱导的RVSMC钙化有保护作用,此作用可能与其阻断RVSMC向成骨细胞转化有关。     

补肾活血含药血清对体外高磷刺激下血管平滑肌细胞钙化的抑制作用

目的:观察补肾活血含药血清对体外高磷刺激下A7r5细胞钙化的抑制作用。方法:用Na H2PO4高磷溶液对体外培养的大鼠血管平滑肌细胞(VSMCs)进行刺激,建立体外血管钙化模型。制备补肾活血含药血清,分别按含药血清在体外培养基中所占比例5%、10%、20%设立补肾活血含药血清低、中、高三个剂量组,进行体外干预10 d。实验结束后,光学显微镜下观察细胞形态;茜素红染色法观察细胞钙化情况,分别在实验第2、4、6、8、10天观察细胞层钙含量及ALP活性,实验第3、6、10天观察细胞VSMCs标记蛋白α-SMA蛋白及成骨细胞标记蛋白ALP蛋白表达。结果:(1)与正常组比较,第10天经茜素红特殊染色,高磷模型组出现明显的钙化结节;同时,细胞钙含量及ALP活性均随时间延长不断升高,α-SMA蛋白表达下调,ALP蛋白表达上调。(2)与高磷模型组比较,第10天经茜素红特殊染色,含药血清低剂量组细胞形态改善不明显,中、高剂量组红色颗粒物明显减少,正常形态细胞数目较多;含药血清组细胞钙含量、ALP活性下降,α-SMA蛋白表达上调,ALP蛋白表达下调。结论:补肾活血含药血清能够减轻高磷所诱导的A7r5细胞钙化及细胞层钙沉积、ALP活性的升高,下调ALP蛋白表达,上调α-SMA蛋白表达,抑制VSMCs向成骨样细胞表型转化。     

补肾活血含药血清对体外高磷刺激下血管平滑肌细胞钙化的抑制作用

目的:观察补肾活血含药血清对体外高磷刺激下A7r5细胞钙化的抑制作用。方法:用Na H2PO4高磷溶液对体外培养的大鼠血管平滑肌细胞(VSMCs)进行刺激,建立体外血管钙化模型。制备补肾活血含药血清,分别按含药血清在体外培养基中所占比例5%、10%、20%设立补肾活血含药血清低、中、高三个剂量组,进行体外干预10 d。实验结束后,光学显微镜下观察细胞形态;茜素红染色法观察细胞钙化情况,分别在实验第2、4、6、8、10天观察细胞层钙含量及ALP活性,实验第3、6、10天观察细胞VSMCs标记蛋白α-SMA蛋白及成骨细胞标记蛋白ALP蛋白表达。结果:(1)与正常组比较,第10天经茜素红特殊染色,高磷模型组出现明显的钙化结节;同时,细胞钙含量及ALP活性均随时间延长不断升高,α-SMA蛋白表达下调,ALP蛋白表达上调。(2)与高磷模型组比较,第10天经茜素红特殊染色,含药血清低剂量组细胞形态改善不明显,中、高剂量组红色颗粒物明显减少,正常形态细胞数目较多;含药血清组细胞钙含量、ALP活性下降,α-SMA蛋白表达上调,ALP蛋白表达下调。结论:补肾活血含药血清能够减轻高磷所诱导的A7r5细胞钙化及细胞层钙沉积、ALP活性的升高,下调ALP蛋白表达,上调α-SMA蛋白表达,抑制VSMCs向成骨样细胞表型转化。     

高磷对血管平滑肌细胞骨钙素mRNA表达和钙沉积的影响

目的 观察高磷对培养的牛主动脉平滑肌细胞骨钙素(OC)mRNA表达和钙沉积的影响,探讨高磷是否为促进血管钙化的独立因素。方法 用不同磷浓度[正常组(Pi 1.5 mmol/L)、高磷组(2.0 mmol/L)]的培养液,培养牛主动脉平滑肌细胞,观察72 h骨钙素的表达,以及不同时间(第3、6、9天)血管平滑肌细胞的钙沉积。上清液中骨钙素浓度用放射免疫法测定。RT-PCR观察骨钙素mRNA的表达。平滑肌细胞钙含量用甲O-酚酞络合酮方法测定。BCA法测定蛋白含量,用蛋白含量标化骨钙素浓度和钙含量。结果 3d后与正常磷组相比,高磷组上清液骨钙素水平明显增高[高磷组(15.03±2.60)pg/μg蛋白比正常磷组(2.98±0.84)pg/μg蛋白,P<0.001];高磷组平滑肌细胞骨钙素mRNA的表达也显著增加(OC/GAPDH:1.91±0.13比0.75±0.04,P<0.001)。高磷组钙沉积显著增加[培养第6天,高磷组(77.19±11.69)μg/mg蛋白比正常磷组(25.77±1.75)μg/mg蛋白,P<0.01],呈时间和剂量依赖性。von Kossa钙染色,高磷组平滑肌细胞中见大量的黑色颗粒沉积。结论 高磷可直接刺激平滑肌细胞的钙沉积和骨钙素产生增加,促进血管平滑肌细胞钙化。高磷血症是促发血管钙化的独立因素。     

金属蛋白酶1组织抑制剂在慢性肾衰竭大鼠钙化动脉中的表达

目的 探讨金属蛋白酶1组织抑制剂（TIMP-1）是否参与慢性肾衰竭大鼠动脉钙化形成。 方法 雄性Wistar大鼠按随机数字表法分组,其中健康对照组8只,实验组36只。用2%腺嘌呤250 mg&#8226;kg－1&#8226;d－1灌胃制备动脉钙化模型。von Kossa染色观察主动脉、股动脉、肾动脉和冠状动脉钙化情况。RT-PCR和Western印迹检测主动脉TIMP-1表达。免疫组织化学方法检测TIMP-1、骨桥蛋白（OPN）、核心结合因子α1（Cbfα-1）在主动脉的表达。 结果 实验组大鼠给药2周后出现明显慢性肾衰竭表现,BUN、Scr、血磷、钙磷乘积和全段甲状旁腺素（iPTH）显著高于对照组（P < 0.01）;给药6周后主动脉、股动脉、肾动脉和冠状动脉中层出现不同程度的钙化。RT-PCR和Western印迹结果显示,实验组大鼠主动脉TIMP-1表达较对照组上调（P < 0.05）,随时间延长呈上升趋势。免疫组化的结果显示,给药后第2、4、6、8周主动脉平滑肌细胞TIMP-1蛋白表达均显著高于对照组（P < 0.05）;钙化主动脉出现Cbfα-1的阳性表达;OPN表达显著增多（P < 0.01)。TIMP-1的表达和OPN及Cbfα-1表达均呈正相关（r = 0.317,P = 0.000;r = 0.485,P = 0.000）。 结论 大鼠腺嘌呤肾衰竭模型血管钙化的病理变化与人类慢性肾衰竭血管钙化相似,是研究慢性肾衰竭血管钙化周期较短、较好的动物模型。TIMP-1高表达和慢性肾衰竭动脉血管钙化相关。     

尿酸对人骨髓间充质干细胞成骨分化中Cbfα1/Runx2表达的影响

目的 观察不同浓度尿酸对人骨髓间充质干细胞(hBMSCs)成骨分化过程中核心结合因子α1(Cbfα1/Runx2)表达变化的影响.方法 以体外培养的健康成年hBMSCs为研究对象,分为5个组,分别为对照组(完全培养基组)和加入不同浓度尿酸(0 mmol/l、0.2 mmol/l、0.4 mmol/l、0.8mmol/l)的成骨诱导组,通过倒置显微镜观察细胞形态,碱性磷酸酶染色和茜素红染色鉴定细胞.在干预诱导第7天和第14天行RT-PCR检测Cbfα1/Runx2的表达.结果 碱性磷酸酶染色和茜素红染色结果均阳性,表示诱导后细胞为成骨细胞.RT-PCR结果表明,对照组各时间点均无Cbfα1/Runx2表达,尿酸培养组随尿酸浓度增加和时间的延长,Cbfα1/Runx2表达逐渐增强,呈现时间依赖性和浓度依赖性.结论 尿酸可能通过促进Cbfα1/Runx2的表达,从而促进hBMSCs向成骨细胞分化.     

高糖通过转化生长因子β信号诱导肾小球内皮细胞向肌成纤维细胞转分化

目的 探讨高糖(HG)能否通过转化生长因子β(TGF-β)途径诱导大鼠肾小球内皮细胞向肌成纤维细胞转分化(EndMT).方法 体外培养大鼠肾小球内皮细胞(GEnC),分为正常对照组(NG,5.5 mmol/L)、高糖组(HG,15、30 mmol/L)、TGF-β抑制剂组(HG+LY36,30 mmol/L葡萄糖+10 μmol/L LY364947)以及高渗对照组(M,5.5 mmol/L葡萄糖+25.5 mmol/L甘露醇)和溶剂对照组(D,5.5 mmol/L葡萄糖+1 ml/LDMSO).采用Western印迹法检测各组细胞内皮细胞标志物claudin5和肌成纤维细胞标志物α-SMA表达变化;实时定量PCR法检测细胞TGF-β1和TGF-β2 mRNA表达改变;免疫荧光法观察细胞形态学变化以及血管内皮细胞标志物VE-cadherin和肌成纤维细胞标志物α-SMA的表达.结果 与NG组比较,HG组claudin5蛋白的表达量随葡萄糖浓度增加而降低(P＜0.05),α-SMA蛋白表达量随葡萄糖浓度增加而升高(P＜0.05),TGF-β1和TGF-β2 mRNA表达均升高(P＜0.05).与HG组比较,TGF-β抑制剂组claudin5蛋白表达量升高(P＜0.05),α-SMA蛋白表达降低(P＜0.05).高渗对照组和溶剂对照组改变差异无统计学意义.激光共聚焦免疫荧光结果显示,高糖处理可引起细胞形态由卵圆形向梭形改变,VE-cadherin表达减少,α-SMA表达增加;TGF-β抑制剂组细胞形态无明显改变.与HG组比较,TGF-β抑制剂组VE-cadherin表达增加,α-SMA表达降低(P＜0.05).结论 高糖诱导大鼠肾小球内皮细胞TGF-β表达增加及内皮细胞-肌成纤维细胞转分化.抑制TGF-β可抑制高糖引起的转分化,提示TGF-β参与了高糖引起的肾小球内皮细胞转分化过程.     

体外高磷环境下血管平滑肌细胞转分化过程的研究

目的 观察体外高磷培养条件下,血管平滑肌细胞（VSMC）向类似成骨样细胞转分化的动态变化特点。 方法 Western印迹和免疫荧光法观察不同磷浓度（1.0、2.5、3.5 mmol/L）培养条件下,人VSMC的标志蛋白α平滑肌肌动蛋白（α-SMA）以及成骨细胞特异性的核转录因子Cbfα1、相关骨基质蛋白（骨桥蛋白、I型胶原和骨钙素）的动态变化过程。实时荧光定量PCR法分析上述指标的基因表达水平。在此基础上,以硝酸银染色和茜素红染色了解细胞的钙盐沉积状况,最后通过电镜观察不同培养条件下细胞超微结构的改变。 结果 在无血清的培养条件下,高磷（2.5、3.5 mmol/L）刺激细胞12 h时,胞内 Cbfα1的表达就明显增加（P ＜ 0.05）;3 d后高磷组（2.5、3.5 mmol/L）细胞中I型胶原和骨桥蛋白的含量显著上调（均P ＜ 0.05）;第6天骨钙素的产生开始增加;15 d时高磷组（2.5、3.5 mmol/L）α-SMA的含量才显著下降（P ＜ 0.05）。实时荧光定量PCR结果显示,高磷环境培养1 d时,细胞中骨桥蛋白、I型胶原的mRNA水平显著升高（均P ＜ 0.05）;5 d时骨钙素的mRNA表达显著增加（P ＜ 0.05）;10 d时α-SMA的mRNA含量显著减少（P ＜ 0.05）。在高磷营养液中培养15 d时,细胞出现多处斑片状的钙盐沉积。电镜可见胞质内产生大量胶原纤维和钙化的基质囊泡。 结论 高磷可诱导VSMC向类似成骨样细胞转分化,这是一个复杂的、有多个环节、有序的动态变化过程。     

Magnesium inhibits β-glycerophosphate-induced calcification of vascular smooth muscle cells by L-type calcium channel α1C and β3 in rats

Objective To explore the effects of L-type calcium channel (LTCC) α1C and β3 subunits on that magnesium inhibited thoracic aortic calcification induced by β-glycerophosphate (β-GP). Methods Vascular smooth muscle cells (VSMCs) and aortic rings from rat aortic were cultured, then divided into control group, high phosphorus group (10 mmol/L β-GP), magnesium group (10 mmol/L β-GP+3 mmol/L MgSO4) and 2-APB (an inhibitor of magnesium transporter) group (10 mmol/L β-GP+3 mmol/L MgSO4+0.1 mmol/L 2-APB). Calcium deposition of VSMCs and aortic rings were respectively measured by alizarin red staining and Von Kossa staining, meanwhile the quantification of their calcium was tested by OCPC. The mRNA expressions of Runx2, LTCC α1C and β3 in VSMCs were detected by RT-PCR, and their protein expressions were detected by Western blotting. Intracellular calcium ion of VSMCs was tested by fluorescence probe and alkaline phosphatase (ALP) activity was measured by ELISA. The Runx2 expression of aortic rings was detected by immunohistochemistry. Results After VSMCs stimulated for 7 days, calcium, ALP, mRNA and protein expressions of LTCCα1C, LTCCβ3 and Runx2, and intracellular calcium ion in high phosphorus group were higher than those in control group (all P＜0.05). Moreover, calcium, ALP, mRNA and protein expressions of LTCCα1C, LTCCβ3 and Runx2, and intracellular calcium ion were decreased in magnesium group as compared with those in high phosphorus group (all P＜0.05). In aortic rings, magnesium group had lower calcium and protein expression of Runx2 than high phosphorus group. No statistical difference between 2-APB group and high phosphorus group was observed in above indexes (all P＞0.05). Conclusion Magnesium may down-regulate expressions of LTCC α1C and β3 subunit, prevent calcium influx and then inhibit osteogenic differentiation so as to reduce β-glycerophosphate-induced VSMCs calcification.     

Effect of vitamin K2 on β-glycerophosphate-induced calcification in rat vascular smooth muscle cells and the mechanism

Objective To explore the effect of vitamin K2 on β-glycerophosphate(β-GP)-induced rat vascular smooth muscle cells (VSMCs) calcification and and the mechanism. Methods VSMCs were obtained from rat aortic, and identified by immunocytochemistry, then randomly divided into control group, high phosphorus group, vitamin K2 group (the group was settled three subgroups according to the concentration of vitamin K2 based on the high phosphorus medium, namely 10 μmol/L, 25 μmol/L, 50 μmol/L) and noggin (bone morphogenetic protein pathway inhibitor) group. Calcification was visualized by Alizarin red staining, calcium load in cells was quantified by o-cresolphthalein complexone method and alkaline phosphatase (ALP) activity was measured after stimulating 14 days, gene expressions of bone morphogenetic protein - 2 (BMP-2), SMAD1, SMAD7 and Runx2 mRNA were detected by RT-PCR, Runx2 protein levels was detected by Western blotting after stimulating 3 days. Results Compared with the cells in control group, high phosphorus induced cell calcification, increased ALP activity, up-regulated the expression of BMP-2, SMAD1, Runx2 mRNA (P＜0.05) and down-regulated the expression of SMAD7 (P＜0.01),while compared with high phosphorus group, the calcium deposition, ALP activity and the expression of BMP-2, SMAD1, Runx2 mRNA were remarkably reduced in a dose-dependent manner by treatment with vitamin K2 (P＜0.05) and the expression of SMAD7 was increased (P＜0.01). Compared with high phosphorus group, SMAD1 and Runx2 expression in noggin group were remarkably reduced(P＜0.01). Conclusion Vitamin K2 inhibits β-glycerophosphate-induced VSMCs calcification which correlates with the suppression of the expression of osteoblast markers through the down-regulation of bone morphogenetic protein pathway.     

Mechanism of Sclerostin/Lrp4 in the regulation of vascular smooth muscle cell calcification

Objective To investigate the possible mechanism of sclerostin/Lrp4 in calcification of VSMC induced by high phosphorus and the protective effect of Ginkgo biloba extract. Methods Aortic vascular smooth muscle cells (VSMCs) of SD rats were extracted and identified. VSMCs were divided into normal control group, high phosphorus induced calcification group (10 mmol/L β-glycerophosphate+50 μg/ml ascorbic acid), and high phosphorus induced calcification+Ginkgo biloba extract intervention group (10 mmol/L β-glycerophosphate+50 μg/ml ascorbic acid+0.5 mg/ml GBE), cultured in different mediums for 14 days. Vonkossa staining and alizarin red staining were used to detect the calcification of VSMCs. The mRNA level of BGP was detected by real time PCR, and the protein expressions of sclerostin and Lrp4 were detected by Western blot. Results Compared with normal control group, vonkossa staining and alizarin red staining showed significant calcium deposition in calcification group. Compared with calcification group, calcium salt deposition was significantly reduced in GBE treatment group. Real time PCR results showed β-catenin and BGP mRNA expressions in VSMC calcification group were higher than those in normal control group (P＜0.05). mRNA expressions of β-catenin and BGP in GBE treatment group were lower than those in calcification group (all P＜0.05). Compared with normal control group, the protein expression of sclerostin was increased, but the protein expression of Lrp4 was decreased in calcified group (all P＜0.05). Compared with calcification group, the protein expression of sclerostin decreased and the protein expression of Lrp4 increased in GBE treatment group (all P＜0.05). Conclusions High phosphorus can induce VSMC calcification by activating Wn/β-catenin signaling pathway. Sclerostin/Lrp4 is involved in hyperphosphine-induced VSMC calcification. GBE can reduce the high phosphorus induced VSMC calcification by regulating the Wnt/β-catenin signaling pathway.     

尿毒症血清诱导的磷酸钙晶体对人主动脉平滑肌细胞的钙化作用

目的 探讨尿毒症患者血清诱导的磷酸钙晶体对人主动脉平滑肌细胞(HASMCs)钙化的影响.方法 尿毒症患者血清在37℃下孵育3d,超速离心法从尿毒症血清中分离磷酸钙晶体和无晶体血清,采用扫描电子显微镜和能量色散X射线光谱仪分析晶体的形态及化学特征.体外培养HASMCs,分为以下4组:对照组、尿毒症血清组、磷酸钙晶体组和无晶体血清组.茜素红染色及甲氧酚酞络合酮法检测HASMCs钙化结节的形成及细胞内钙含量.实时荧光定量PCR法检测骨形态发生蛋白2(BMP-2)、骨桥蛋白(OPN)、核结合因子α1亚基(Cbfα1)、碱性磷酸酶(ALP)、基质γ羧基谷氨酸蛋白(MGP)的mRNA表达.Cbfα1、OPN和BMP-2的蛋白表达用Westcrn印迹和ELISA法检测.结果 尿毒症血清可诱导磷酸钙晶体形成.与对照组相比,尿毒症血清明显促进HASMCs钙化结节形成,增加细胞内钙含量(P＜0.05),并上调细胞BMP-2、OPN、Cbfα1的mRNA和蛋白表达(均P＜ 0.01);而磷酸钙晶体亦促进HASMCs钙化结节的形成,增加细胞内钙含量(P＜0.05),上调BMP-2、OPN、Cbfα1的mRNA和蛋白表达(均P＜0.01).无晶体血清组的HASMCs胞内钙含量和上述成骨蛋白的表达与对照组差异无统计学意义(均P＞ 0.05).结论 尿毒症血清可能通过诱导磷酸钙晶体的形成促进血管钙化的发生.     

Pyrrolidine-dithio-carbamate ammonium counteracts high-phosphate-induced aortic calcification by inhibiting p65 nuclear translocation in uremic rats

Objective To investigate the effects of pyrrolidine-dithio-carbamate ammonium (PDTC) on high-phosphate-induced vascular calcification in uremic rats. Methods Eight-week-old SD rats were pair-fed with standard chow containing 1.2% calcium and 0.6% phosphorus for the control group (n=8) or 0.75% adenine, 1.2% calcium, and 1% phosphorus for the chronic renal failure(CRF) group (n=8) or PDTC group (intraperitoneal injection, 100mg•kg-1•d-1, n=8) for 8 weeks. The abdominal aortas were excised for Western blotting and immunostaining assay of NF-κB p65, osteopontin (OPN) and core binding factor α1(Cbfα1) protein. Results Serum urea nitrogen, creatinine, inorganic phosphate, calcium-phosphorus product increased significantly in CRF group and PDTC group after 4 weeks and 8 weeks (all P﹤0.01), although no differences were found between the latter two groups. After 8 weeks, aortic calcification was found in these two groups, immunostaining assay revealed OPN and Cbfα1 expressed in aortic intima, media and adventitia, and Western blotting analysis showed that total NF-κB p65, nuclear phosphorylated-p65 (p-p65), OPN and Cbfα1 expressions were significantly higher than those in control group (all P﹤0.01). The expression of total p65 and p-p65 was positively correlated with Cbfα1(r=0.707, P﹤0.01; r=0.507, P﹤0.01). Conclusion PDTC alleviates inorganic phosphate-induced aortic calcification significantly by inhibiting the nuclear translocation of NF-κB p65 and the expression of Cbfα1.     

Expression of core?binding factor alpha 1 and collagen Ⅱ in patients with chronic kidney disease stage 5

Objective To study the relationship between the medial artery calcification and expression of core?binding factor alpha 1 (Cbfα?1) and collagen Ⅱ (ColⅡ) in chronic kidney disease(CKD) stage 5 patients. Methods Pieces of radial arteries were taken from 40 patients with CKD stage 5 during internal arteriovenous fistula operation. Ten patients with subtotal gastrectomy and normal renal function were chosen as control. The vessels were examined for calcification by von Kossa stain and for the presence of Cbfα?1 and ColⅡ by immunohistochemistry. According to von Kossa stain, CKD stage 5 patients were divided into no calcification group, mild?moderate calcification group and severe calcification group. Other related factors including serum calcium，phosphate, intact parathyroid hormone (iPTH), C?reactive protein (CRP), triglyceride(TG), cholesterol(TC) and low?density lipoproteins(LDL) were also detected. Results Seventeen (42.5%) of CKD Stage 5 patients showed vascular calcification, while calcification was not found in controls. Most calcification occurred in medial layer．Positive immunohistochemical staining of core?binding factor and ColⅡ was found in the smooth muscular cell plasma of medial layer in the vessels with calcification. However, above positive staining was also observed in 78.3% of no calcification group. But there was little staining in control group. Positive staining score of Cbfα?1 and ColⅡ in severe calcification group was significantly higher than that in no calcification group. Same findings were obtained in mild?moderate calcification group, but the difference between them was not statistically significant. CRP and Ca×P were positively correlated with staining score of Cbfα?1 and ColⅡ. Serum phosphate was positively correlated with Cbfα?1 (r=0.786, P<0.01) and ColⅡ (r=0.785, P<0.01) respectively． Conclusions 42.5% of CKD stage 5 patients in our group shows vascular calcification, which occurrs mainly in medial layer. High expression of Cbfα?1 and ColⅡ can be observed in vascular calcification of radial arteries, which is earlier than vascular histological changes. Cbfα?1 and ColⅡ may be involved in the development of vascular calcification.