Pro‐elastogenic effects of bone marrow mesenchymal stem cell‐derived smooth muscle cells on cultured aneurysmal smooth muscle cells

Abdominal aortic aneurysms (AAAs) involve slow proteolysis and loss of structural matrix components (collagen and elastin), which lead to wall thinning, weakening and ultimate rupture. At this time, no established non‐surgical therapy is available to slow or arrest AAA growth. Inhibiting matrix metalloproteases (MMPs; e.g. MMP2 and ?9) overexpressed within AAAs is insufficient to arrest AAA growth, since resident smooth muscle cells (SMCs) are poorly elastogenic and cannot overcome elastolysis to reinstate a healthy elastic matrix. Towards overcoming this limitation, this first study sought to determine the utility of rat bone marrow mesenchymal stem cell (BM‐MSC)‐derived SMCs to stimulate elastin and elastic matrix synthesis and assembly by aneurysmal SMCs (EaRASMCs). BM‐MSCs were successfully differentiated into cells of an SMC lineage (SMLCs). Our study indicates that BM‐MSC‐derived SMLCs secrete trophic factors, contained in conditioned medium (CM) from their cultures, that, when exposed to EaRASMC cultures in real time, stimulate elastin precursor and matrix deposition and crosslinking by these elastogenically deficient cells, with added benefits in terms of attenuating MMPs, specifically MMP9. The results thus lend support to a proposed cell therapy for AAAs, based on the use of BM‐MSC‐derived SMLCs. Although we observed no particular improvement in elastic fibre formation, no attenuation of MMP2 activity and increase in amounts of active MMP2 enzyme, we believe that this study justifies follow‐up studies to improve upon these outcomes. Future studies will explore the effects of concentrated CM collected from long‐term SMLC cultures on EaRASMCs and also investigate the elastogenic output of SMLCs themselves. Copyright © 2014 John Wiley & Sons, Ltd.     

南宁地区动脉内膜结蛋白与动脉粥样硬化的观察

连续１２例意外死亡的广西自治区南宁市年轻人（１５～３４岁）免疫组化染色证明，其主动脉及冠状动脉内膜的平滑肌细胞含有较多结蛋白。南宁是我国动脉粥样硬化最低发区之一，也是世界低发区。结蛋白阳性是平滑肌细胞成熟的标志。成熟平滑肌细胞为收缩型细胞，不易受生长因子作用而活跃增殖。因而认为这可能是动脉粥样硬化低发区的特征。与北京相比较，本地区动脉壁含较多具有抗增殖活性的硫酸乙酰肝素蛋白聚糖。平滑肌细胞产生这种聚糖构成细胞外层，像筑茧自缚一样抑制自身生长，因而平滑肌细胞比较成熟稳定，显示较多结蛋白。     

PCNA的反义寡核苷酸抑制血管内皮剥脱后SMC增殖的研究

本研究采用增殖细胞核抗原(PCNA)的反义寡核苷酸,探讨其抑制大鼠血管内皮剥脱1周时平滑肌细胞(SMC)的增殖反应(每只大鼠给200μg寡核苷酸).结果发现:PCNA的正义寡核苷酸及Pluronic F127(用于转移寡核苷酸)对大鼠血管内皮剥脱1周时SMC的增殖无显著影响(与内皮剥脱组相比,P>0.05).PCNA的反义寡核苷酸一定程度地抑制大鼠血管内皮剥脱1周时SMC的增殖(与内皮剥脱组相比,P<0.01,与正常组相比,P<0.01.说明PCNA的反义寡核苷酸抑制大鼠血管内皮剥脱后SMC的增殖.     

调肝导浊方对体外培养主动脉平滑肌细胞增殖影响的实验研究

为探讨中药调肝导浊方（由熟地黄,柴胡,草决明等组成）治疗动脉粥样硬化的机理,运用体外培养技术,培养大鼠主动脉平滑肌细胞（SMC）,以高脂血清以及加中药等不同培养基进行分组培养,取细胞进行指标检测,观察调肝导浊中药对主动脉SMC增殖的影响,结果：调肝导浊方能明显抑制高脂血清培养下SMC的增殖,其细胞增殖核抗原（PCNA）阳性率低于造模组（P＜0．01）。     

西红花苷对平滑肌细胞增殖的影响及机制研究

目的:探讨西红花苷对平滑肌细胞增殖的影响及作用机制.方法:在体外培养牛主动脉平滑肌细胞,观察西红花苷对由20%新生牛血清及氧化性低密度脂蛋白(Ox-LDL)所致的血管平滑肌细胞增殖的作用,在鹌鹑饮食性动脉粥样硬化模型上观察了西红花苷预防性给药连续9周对血清低密度脂蛋白(LDL)和血清过氧化脂质(LPO)的影响.结果:西红花苷可抑制由20%新生牛血清及氧化性低密度脂蛋白(Ox-LDL)所致的牛主动脉血管平滑肌细胞增殖,西红花苷能显著降低血清低密度脂蛋白(LDL)及血清MDA的水平.结论:西红花苷对氧化性低密度脂蛋白所致的平滑肌细胞增殖的抑制作用与其能降低体内LDL水平及抗氧化作用有关.     

Angiographic evaluation of the rat carotid balloon injury model

Rationale

The rat carotid balloon-injury (BI) model is a widely used model of intimal hyperplasia (IH) and vascular remodeling. A variable degree of IH after BI has been previously reported, and we have encountered technical challenges and suboptimal results with the original method.

Objective

To evaluate the original rat carotid artery BI method with the use of micro-angiography. We tested the hypothesis that in order to obtain an optimal arterial response, BI should be limited to the common carotid artery with preservation of blood flow.

Methods and results

The left common carotid artery (CCA) was injured by one of three different methods. Carotid angiograms and pathology were examined 14 days after BI.A 2 F Fogarty balloon catheter inflated to 2 atm inside the aortic arch would not slide back into the common carotid artery until deflation to 0.5 to 0.7 atm. Four out of five (80%) vessels injured with this method developed excessive inflammation without discernible IH. Six out of nine (66%) arteries that underwent BI limited to the CCA at 2 atm developed the largest angiographic stenosis (p = 0.003) and IH (0.20 ± 0.03 mm², p = 0.028). Ten out of eleven (91%) arteries injured with a variable pressure of 1.5 to 2.2 atm, based on the operator's feedback, developed considerable IH (0.12 ± 0.02 mm²). All injured carotid arteries with preserved blood flow on angiography developed IH with intact histological boundaries.

Conclusions

Optimal IH with preservation of histological boundaries is achieved by graded BI limited to the CCA that preserves carotid blood flow.     

竖直上升管的煤粉密相气力输送阻力特性的实验研究

研究了SMC晶须/高密度聚乙烯复合材料的结晶结构,着重对比了静态注射样品和动态保压注射样品的多层结晶结构和形貌。静态注射样品具有皮层和芯层2层结构,而动态保压注射样品则存在皮层、剪切层和芯层3层结构。示差扫描量热分析(DSC)结果表明:SMC晶须对高密度聚乙烯结晶具有促进作用,样品各层的结晶度都随着晶须含量的增加而变大,在剪切力最强的剪切层这种促进作用更为明显。广角衍射(WAXD)和小角散射（SAXS）结果表明剪切层具有很高的取向度。剪切层的高结晶度和高取向度的特点使动态注射样品具有更优异的力学性能。     

Mechanisms of human smooth muscle cell proliferation and transplant vasculopathy induced by HLA class I antibodies: In vitro and in vivo studies

Vascular smooth muscle cells (SMC) play an important role in the pathophysiology of transplant vasculopathy (TV), a major cause of late death in patients receiving an organ transplant. In this review we describe the proliferative effect in vitro and in vivo of HLA class I antibodies on human SMC. We have developed an experimental model using segments of human mesenteric arteries transplanted in the position of the infrarenal aorta in immunodeficient mice (SCID/beige). Weekly injections of transplanted mice with a monoclonal antibody towards HLA class I provoked typical lesions of TV after 6 weeks in the human graft while transplanted mice receiving an irrelevant antibody did not develop any significant lesion. In vitro, the anti-HLA antibodies were mitogenic to SMC and we showed that they activate a stress-induced signaling pathway implicating matrix metalloproteinases (MMP) and neutral sphingomyelinase 2 (nSMase-2). The proliferative effect of anti-HLA antibodies could be blocked by pharmacological inhibitors or by siRNA. Administration of pharmacological inhibitors diminished the development of TV in grafted mice injected with anti-HLA antibodies demonstrating an important role of the MMP/nSMase-2 pathway in antibody-induced TV. This observation opens new perspectives for the management of TV in clinical settings.