Matrix Gla protein negatively regulates calcification of human aortic valve interstitial cells isolated from calcified aortic valves

Calcified aortic valve stenosis (CAS) is a common heart valve disease in elderly people, and is mostly accompanied by ectopic valve calcification. We recently demonstrated that tumor necrosis factor-α (TNF-α) induces calcification of human aortic valve interstitial cells (HAVICs) obtained from CAS patients. In this study, we investigated the role of matrix Gla protein (MGP), a known calcification inhibitor that antagonizes bone morphogenetic protein 2 (BMP2) in TNF-α-induced calcification of HAVICs. HAVICs isolated from aortic valves were cultured, and calcification was significantly induced with 30 ng/mL TNF-α. Gene expression of the calcigenic marker, BMP2, was significantly increased in response to TNF-α, while the gene and protein expression of MGP was strongly decreased. To confirm the role of MGP, MGP-knockdown HAVICs and HAVICs overexpressing MGP were generated. In HAVICs, in which MGP expression was inhibited by small interfering RNA, calcification and BMP2 gene expression were induced following long-term culture for 32 days in the absence of TNF-α. In contrast, HAVICs overexpressing MGP had significantly decreased TNF-α-induced calcification. These results suggest that MGP acts as a negative regulator of HAVIC calcification, and as such, may be helpful in the development of new therapies for ectopic calcification of the aortic valve.     

大鼠同种带瓣主动脉移植模型的建立和改进

目的 为了简化手术步骤，方便操作，提高手术成功率。方法 采用wistar大鼠(200～250g)为供体，sD大鼠(200～250g)为受体，行同种带瓣主动脉腹主动脉补片式异位移植36例。供体经修剪保留两个主动脉瓣叶及相应宽度瓣下附着心肌(0．5mm)和主动脉壁(5mm)，三定点连续缝合法移植于左肾静脉下方腹主动脉前壁。结果 手术成功率为94．4％。结论 实验结果提示：与腹主动脉间置式移植相比，本手法操作简单，成功率高，可满足类似实验要求。     

主动脉瓣膜间质细胞分化机制研究进展

瓣膜纤维化或钙化是瓣膜性心脏病(VHD)的两大重要病理表现,其中瓣膜间质细胞(VICs)由成纤维细胞样表型分化为肌成纤维细胞表型或成骨细胞表型,是瓣膜发生早期病理改变的关键环节。VHD多累及主动脉瓣,近年来有关VICs分化的研究多聚焦于主动脉瓣来源细胞。本文就主动脉瓣VICs分化的最新研究进展予以综述,旨在为VHD的防治研究提供更为全面的参考。     

经导管主动脉瓣置换术2016年进展回顾

经导管主动脉瓣置换术（transcatheter aortic valve replacement, TAVR）是一种革命性的新技术。经过14年的成长,现国际上TAVR已发展得相当成熟,正在向精细化方向发展。2016年发表的有关TAVR的研究报告数量很多,但许多研究探讨的都是TAVR的技术细节或特定的临床问题,而非之前那样从总体上观察TAVR的效果、死亡率和并发症等。本文回顾2016年TAVR的重要进展。     

主动脉瓣钙化与冠心病的关系研究

目的探讨主动脉瓣钙化与冠心病发病之间的关系。方法回顾性研究同期行冠状动脉造影检查和超声心动图检查患者653例,并对所有患者分组：正常对照组和主动脉瓣钙化组（左冠瓣钙化、右冠瓣钙化,主动脉瓣多瓣膜钙化）,对比研究主动脉瓣钙化组与正常对照组间冠心病发病率差异,同时比较单瓣主动脉瓣钙化与冠状动脉狭窄是否发生于同侧。结果主动脉瓣钙化组冠心病的检出率明显高于正常对照组,单瓣主动脉瓣钙化与同侧冠脉狭窄无明显相关性。结论主动脉瓣钙化患者有更高的冠心病发病率,主动脉瓣钙化可以作为冠心病无创评估的一个参考指标。     

主动脉瓣狭窄的介入治疗现状与进展

主动脉瓣狭窄（Aortic valve stenosis,AVS）是目前老年人最常见的心脏瓣膜疾病。随着人口老龄化时代的到来,主动脉瓣狭窄患者人数逐年增加,对该病的治疗面临着重大挑战。然而由于介入心脏病学的迅猛发展,外科手术已不再作为此类患者治疗的唯一选择,经皮主动脉瓣置换术（Percutaneous aortic valve replacement,PAVR）已经成为可行,这一技术的广泛开展,给众多无法接受传统外科治疗的患者带来了希望。     

腹透患者心血管钙化的发生率、分布特点及相关影响因素

目的：通过对腹膜透析患者的心脏瓣膜钙化及主动脉弓钙化进行评价,分析心血管钙化的发生率、分布特点及相关影响因素。方法选取174例腹膜透析患者,分别于统一时间段测量肢肱动脉血压,分别记录患者的血尿素氮、肌酐值;24 h的尿量、透出液量、尿素氮、肌酐值及透出液尿素氮、肌酐浓度值;并通过上述测定值计算评估透析充分性和残余肾功能。每隔6个月测定患者的生化指标。对腹膜透析患者心脏进行多普勒超声检查和患者胸部X线片检查,用Logistics回归分析评判心血管钙化危险因素。结果主动脉弓钙化及瓣膜钙化类别中钙化患者的年龄、透析龄及血磷值均高于非钙化患者（ P ＜0．05）;钙化患者的残余肾功能值显著低于非钙化患者（ P ＜0．05）;随着年龄／透析龄的增加,瓣膜／主动脉弓钙化的发生率显著上升（ P ＜0．05）。年龄、透析龄和钙磷乘积均是影响心脏瓣膜钙化的独立危险因素（ P ＜0．05）,其中钙磷乘积危险系数最高;年龄、透析龄和血磷是影响主动脉弓钙化的独立危险因素（ P ＜0．05）,其中血磷危险系数最高;残余肾功能是能影响心脏瓣膜／主动脉弓钙化的独立因素（ P ＜0．05）,而且是保护因素。结论年龄和透析龄是影响心脏瓣膜钙化及主动脉弓钙化的独立危险因素,钙磷乘积是影响心脏瓣膜钙化危险系数最高的独立因素,血磷是影响主动脉弓钙化危险系数最高的独立因素。     

经导管主动脉瓣置换术的研究进展

主动脉瓣狭窄(AS)是老年人最常见的瓣膜退行性改变,发病率正逐年上升.经导管主动脉瓣置换术(TAVR)的临床应用为AS患者提供了一种全新的治疗方法 ,目前TAVR已经成为不能进行外科手术或具有高外科手术风险的重度AS患者的有效替代治疗方案.欧美国家开展的TAVR注册研究进一步肯定了TAVR的效果.近期一些重要的随机对照临床试验及注册研究结果 已经报道,现将近期重要的试验结果 作一综述.     

钙化生物瓣组织钙磷含量关系及钙化原因初探

钙化是造成生物瓣远期衰败和限制其临床应用范围的主要原因之一。对生物瓣钙化机制以及防止或延缓生物瓣钙化的研究，一直是瓣膜外科的热门课题。本文通过建立生物瓣钙化动物模型及钙化生物瓣组织钙磷含量关系的分析和组织学检查，发现在无交变应力及血液接触的情况下，仍可发生钙化。钙化组织中钙磷的增长速度基本相同，钙磷含量之间呈明显正相关，钙化处组织疏化，胶原断裂、肿胀、排列紊乱。这些结果说明，机械应力和血流接触并非     

维持性血液透析患者腹主动脉钙化情况及其相关因素分析

目的 应用腹部侧位X线平片检测维持性血液透析患者腹主动脉钙化(AAC)情况,并探讨其相关因素.方法 收集82例维持性血液透析患者的临床资料,通过腹部侧位X线平片检测腹主动脉钙化的发生情况,同时检测患者的血常规、血糖、肾功能、血脂、血钙、血磷及全段甲状旁腺素(iPTH)水平,依据是否发生腹主动脉钙化将患者分成AAC组与非AAC组,进行相关统计学分析.结果 82例血液透析患者中有55例(67.1％)发生腹主动脉钙化,钙化主要发生于L4,并且从L1向L4钙化发生逐渐加重.组间对比分析显示,AAC组患者的年龄较大(P＜0.05)且透析龄更长(P＜0.01),低密度脂蛋白及钙磷乘积水平明显高于非AAC组(P＜0.05),此外原发病为糖尿病肾病患者的腹主动脉钙化发生率高于非AAC组(P＜0.05).结论 维持性血液透析患者有较高的腹主动脉钙化发生率,其发生可能与年龄、低密度脂蛋白、钙磷乘积水平、透析龄及原发病为糖尿病等因素有关.     

骨形态发生蛋白与抗骨质疏松药物研究进展

骨形态发生蛋白能够增加成骨细胞分化的标志酶——碱性磷酸酶和骨钙蛋白等基因的表达，促进新骨形成及骨的层次化，在成骨细胞分化过程中起关键作用，有可能成为骨质疏松症防治药物的重要作用靶点。随着对骨形态发生蛋白2（BMP-2）研究的深入，越来越多的化合物破发现有上调BMP-2的作用，其中包括他汀类药物、白藜芦醇、秦皮素、红曲及雌激素等。现就近年来在骨形成的分子机制和以骨形态形成蛋白为靶点抗骨质疏松药物的研究进展进行综述。     

丹参素对血管平滑肌细胞钙化和凋亡的抑制作用

目的：探讨丹参素对血管平滑肌细胞（VSMCs）凋亡和钙化的影响。方法：β-磷酸甘油诱导培养的VSMCs发生钙化;通过细胞钙含量和碱性磷酸酶（ALP）活性测定,判断钙化程度;用Western blot方法检测细胞中骨形成蛋白BMP-2、凋亡相关蛋白Bax、Bcl-2和cleaved caspase 3的蛋白水平。结果：与正常组相比,β-磷酸甘油引起VSMCs中钙含量和ALP活性明显增加。丹参素显著抑制β-磷酸甘油引起的钙化VSMCs中的钙含量和ALP活性。Western blot结果显示β-磷酸甘油可引起VSMCs中BMP-2,bax和cleaved caspase 3的蛋白水平显著增高,Bcl-2蛋白水平明显降低;丹参素可明显改善钙化的VSMCs中上述蛋白的变化。结论：丹参素可以抑制VSMCs发生钙化和凋亡,此效应可能与抑制BMP-2、bax和cleaved caspase 3的蛋白水平,上调Bcl-2蛋白水平有关。     

盐酸二甲双胍对成骨细胞增殖、BMP-2及Cbfa-1基因表达的影响

目的初步研究二甲双胍（MF）在体外对小鼠颅盖骨成骨细胞增殖、骨形态发生蛋白一2（BMP一2）及核心结合因子（Cbfa一1）mRNA表达的影响,探讨二甲双胍对骨代谢的可能作用机制。方法（1）分离培养原代颅盖骨成骨细胞并对其进行鉴定。（2）以乳鼠成骨细胞为体外实验模型,不同浓度（0、50、100、200、400Ixmol／L）的MF干预体外培养的成骨细胞24h后,M1vr法检测成骨细胞的增殖能力,实时荧光定量PCR法检测成骨细胞BMP-2及Cbfa-1基因表达。结果二甲双胍干预成骨细胞24h后,可促进成骨细胞的增殖,在浓度400μxmol／L的OD值最大为0．298±0．047（P〈0．05）;可促进BMP-2及Cbfa-1mRNA的表达,呈剂量效应关系。结论二甲双胍可促进成骨细胞的增殖和分化,可能通过调节BMP-2及Cbfa-1的表达,从而促进骨的形成。     

Histopathological study of congenital aortic valve malformations in 32 children

The histopathological characteristics of congenital aortic valve malformations in children were investigated. All the native surgically excised aortic valves from 32 pediatric patients suffering from symptomatic aortic valve dysfunction due to congenital aortic valve malformations between January 2003 and December 2005 were studied macroscopically and microscopically. The patients’ medical records were reviewed and the clinical information was extracted. The diagnosis was made by the clinical presentation, preoperative echocardiography, intraoperative examination, and postoperative histopathological study, excluding rheumatic or degenerative aortic valve diseases, infective endocarditis and primary connective tissue disorders, e.g. Marfan syndrome. Among 32 children with congenital aortic valve malformations, the age was ranged from six to 18 years, with a mean of 14.9 years, and there were 27 boys and five girls (male: female = 5.4:1). There were five cases of aortic stenosis (AS, 15.62%), 25 cases of aortic insufficiency (AI, 78.13%) and two cases of AS-AI (6.25%), without other valve diseases. Twenty cases still had other congenital heart diseases: ventricular septal defect (19 cases), patent ductus arteriosus (two cases), double-chambered right ventricle (one case), aneurysm of the right anterior aortic sinus of valsalva (three cases). Histopathological examination indicated that the cusps became thickening with unequal size, irregular shape (coiling and prolapse edge), enhanced hardness, and partly calcification. Microscopic investigation revealed the unsharp structure of valve tissue, fibrosis, myxomatous, reduced collagen fiber, rupture of elastic fibers, different degrees of infiltration of inflammatory cells, secondary calcareous and lipid deposit, and secondary fibrosis. Congenital aortic valve malformations in children involve males more than females, mostly associated with other congenital heart diseases. Aortic insufficiency is more common in children with congenital aortic valve malformations. Histopathologically, the leaflets of aortic valve are mainly myxomatous, thickening with unequal size, irregular shape (coiling and prolapse edge), reduced collagen fiber, rupture of elastic fibers, without small vessel proliferation and inflammatory cell infiltration, fibrosis and calcification rarely seen. Translated from Chin J Evid Based Pediatr, 2006, 1(2): 130–133 [译自: 中国循证儿科杂志]     

Improvement of aortic valve stenosis by ApoA-I mimetic therapy is associated with decreased aortic root and valve remodelling in mice

Background and Purpose

We have shown that infusions of apolipoprotein A-I (ApoA-I) mimetic peptide induced regression of aortic valve stenosis (AVS) in rabbits. This study aimed at determining the effects of ApoA-I mimetic therapy in mice with calcific or fibrotic AVS.

Experimental Approach

Apolipoprotein E-deficient (ApoE^−/−) mice and mice with Werner progeria gene deletion (Wrn^Δhel/Δhel) received high-fat diets for 20 weeks. After developing AVS, mice were randomized to receive saline (placebo group) or ApoA-I mimetic peptide infusions (ApoA-I treated groups, 100 mg·kg⁻¹ for ApoE^−/− mice; 50 mg·kg⁻¹ for Wrn mice), three times per week for 4 weeks. We evaluated effects on AVS using serial echocardiograms and valve histology.

Key Results

Aortic valve area (AVA) increased in both ApoE^−/− and Wrn mice treated with the ApoA-I mimetic compared with placebo. Maximal sinus wall thickness was lower in ApoA-I treated ApoE^−/− mice. The type I/III collagen ratio was lower in the sinus wall of ApoA-I treated ApoE^−/− mice compared with placebo. Total collagen content was reduced in aortic valves of ApoA-I treated Wrn mice. Our 3D computer model and numerical simulations confirmed that the reduction in aortic root wall thickness resulted in improved AVA.

Conclusions and Implications

ApoA-I mimetic treatment reduced AVS by decreasing remodelling and fibrosis of the aortic root and valve in mice.     

胞外pH值通过BMP-2信号通路影响高磷诱导的血管平滑肌细胞钙化

目的 探讨骨形态发生蛋白2（bone morphogenetic protein 2,BMP-2）信号通路在不同pH值环境影响高磷诱导的大鼠血管平滑肌细胞（vascular smooth muscle cells, VSMCs）钙化中的作用。方法 选取5～8周龄健康雄性SD大鼠,体外分离培养大鼠胸主动脉VSMCs,采用免疫细胞化学方法鉴定。将VSMCs用随机抽样法分为正常对照组(pH7.4)、pH7.4+高磷组、pH7.1+高磷组及pH7.7+高磷组。采用茜素红染色及邻甲酚酞络合酮比色法检测细胞钙化情况,酶联免疫吸附法检测细胞碱性磷酸酶(ALP)活性,用反转录聚合酶链反应（RT-PCR）法检测BMP-2、Smad1及 Runt 相关转录因子2（Runx2） mRNA的表达。结果 与正常对照组相比,pH7.4+高磷组大鼠VSMCs的钙含量增加（P<0.05）、茜素红染色钙化结节增多,Runx2 mRNA表达及ALP活性均增高（P<0.05）;与pH7.4+高磷组相比,pH7.1+高磷组大鼠VSMCs的钙含量减低（P<0.05）、茜素红染色钙化结节减少,Runx2 mRNA表达及ALP活性均降低（P<0.05）,BMP-2、Smad1mRNA表达均降低（P<0.05）,pH7.7+高磷组大鼠VSMCs的钙含量增加（P<0.05）、茜素红染色钙化结节增多,Runx2 mRNA表达及ALP活性均增高（P<0.05）,BMP-2、Smad1mRNA表达均增高（P<0.05）。结论 胞外酸性环境（pH7.1）抑制高磷诱导的大鼠VSMCs钙化,胞外碱性环境（pH7.7）促进高磷诱导的大鼠VSMCs钙化,其机制可能是通过BMP-2信号通路介导了VSMCs的表型转化。     

脱除人主动脉瓣膜细胞的研究

目的探讨人主动脉瓣叶去细胞后作为组织工程心脏瓣膜支架的可行性。方法经胰酶-EDTA、表面活性剂和核酸酶处理,去除人主动脉瓣叶的细胞成分,测定瓣叶去细胞前、后的生物力学特性。结果人主动脉瓣去细胞后,经光镜和电镜观察,脱细胞后血管壁无细胞残留,胶原纤维和弹性纤维保留完整,形态学无明显变化;生物学性能也没有明显改变。结论去细胞效果良好,初步制造了同种主动脉血管壁脱细胞基质材料,为构建同种带瓣管道提供了较合适的材料。     

骨髓间质干细胞移植对钙化主动脉功能及骨桥蛋白表达水平的影响

目的:研究骨髓间质干细胞(MSCs)对于大鼠血管尤其是大血管钙化的修复作用,探讨MSCs逆转血管钙化的可能性,寻找改善严重血管损伤的新途径.方法:选用8周龄健康Wister鼠作为研究对象,采用尼古丁与维生素D3联合干预方法制作血管钙化模型,检测干细胞移植对于组织钙含量、骨桥蛋白表达水平的影响,并对结果进行统计学分析.结果:MSCs干预组大鼠主动脉组织钙含量明显低于单纯造模组(P＜0.05),组织中钙容积分数与未干预组相比也明显降低;同时MSCs还能够明显抑制局部组织中骨桥蛋白的表达.结论:MSCs移植治疗可以通过抑制骨桥蛋白表达等途径调节钙在血管组织局部的沉积,改变血管中钙含量,从而有效地逆转血管钙化的过程,这种结构的变化同样伴有功能的改变.