以脂质代谢和氧化应激为靶点的动脉粥样硬化治疗研究进展

动脉粥样硬化是一种慢性炎症性疾病，脂质代谢障碍和氧化应激反应加速了病变过程。
本文介绍了基础研究中以调节脂质代谢和改善氧化应激为目标的治疗方法。调节脂质代谢的治疗方
法包括：①前蛋白转化酶枯草溶菌素9型（PCSK9）小分子抑制剂：不仅能够抑制前蛋白转化酶枯草
溶菌素9型的活性，而且能增加肝细胞表面LDL受体；②纳米颗粒miR-chNPs（miR206-chNPs和miR223-
chNPs）：通过调节转录后基因表达，促进胆固醇外排。改善氧化应激的治疗方法包括：①抗氧化剂
硒纳米颗粒：通过抗氧化剂硒酶或硒蛋白维持体内的氧化还原稳态；②硫氧还原蛋白1模拟肽：通
过其抗氧化和蛋白质信号转导来发挥功能；③组蛋白脱乙酰酶抑制剂：通过抑制氧化应激延缓动
脉粥样硬化病变形成。基于基础研究的新靶点治疗方法，是未来具有潜力的治疗动脉粥样硬化疾病
的新兴方法。     

脑缺血大鼠脑皮质中前蛋白转化酶枯草溶菌素9 mRNA的经时表达

氧化的低密度脂蛋白是脑血管病的危险因素,而前蛋白转化酶枯草溶菌素9能升高低密度脂蛋白的水平。因此,课题组设想前蛋白转化酶枯草溶菌素9可能在缺血性脑血管病中发挥作用。实验以阻塞大鼠大脑中动脉100 min后进行再灌注建立短暂性局灶性脑缺血模型,原位杂交染色发现脑缺血大鼠脑皮质内前蛋白转化酶枯草溶菌素9 mRNA表达随再灌注时间延长而增高。说明局灶性短暂脑缺血可上调大鼠缺血脑皮质内前蛋白转化酶枯草溶菌素9 mRNA的表达。 关键词：前蛋白转化酶枯草溶菌素9 mRNA;皮质;脑缺血;大鼠;神经再生     

PCSK9与急性脑梗死关系的研究进展

<正>前蛋白转化酶枯草溶菌素 9(PCSK9)是近年来发现的前蛋白转化酶(proproteinconvertases,PCs)的新成员,能够通过细胞内及细胞表面途径促进LDLR降解,导致血清LDL-C水平升高。对脂质代谢、动脉粥样硬化、炎症反应、细胞凋亡和缺血性脑卒中的发生进展至关重要,最新的研究表明其与胰岛素抵抗及血糖代谢也有密切关系。PCSK9基因功能获得性 (GOF) 突变及功能缺失型突变( LOF)能够对血脂水平及脑卒中产生不同的作用     

绿茶及绿茶多酚对阿尔茨海默病的神经保护作用

氧化应激反应在阿尔茨海默病（AD）的发生中具有重要作用。绿茶及绿茶多酚作为公认的抗氧化剂，可减轻脂质过氧化反应，抑制氧化性DNA损伤，进而调节细胞凋亡过程，并可能抑制胆碱酯酶活性，干预淀粉样前体蛋白的生物合成，减轻淀粉样蛋白的沉积，从而干预AD的病理过程，发挥神经保护作用。     

去炎松-A固体脂质纳米颗粒透皮吸收在瘢痕治疗中的效应

目的：为克服目前瘢痕非手术治疗中糖皮质激素治疗的副作用，尝试应用去炎松-A固体脂质纳米颗粒经透皮吸收技术治疗瘢痕，观察其效果。 方法: 实验于2007-04/08在解放军兰州军区总医院动物实验中心实验室进行。①造模：选用新西兰白兔16只，每个兔耳上将全层皮肤切除，形成1 cm×1 cm上、下两个创面，术后30 d上皮化生逐渐形成病理性瘢痕。②分组干预：造模成功后随机分为对照组和实验组，每组8只。对照组不干预，实验组于术后30 d起应用含有去炎松-A 1 mg/cm2 的固体脂质纳米颗粒卡波姆凝胶覆于已形成的瘢痕上透皮吸收。③观察指标：分别于模型形成后第30，60，90和120天时依次取每只大白兔左耳上、下，右耳上、下的病理性瘢痕作为标本来源进行组织病理学观察，同时采用免疫组化检测组织中的ki-67表达和羟脯氨酸含量，并抽静脉血测血中皮质醇浓度。 结果：16只白兔均进入结果分析。①实验组做模型后第30天时ki-67表达及羟脯氨酸含量与对照组比较无明显差异（P > 0.05），但第60，90和120天实验组瘢痕组织中表达及羟脯氨酸含量较对照组明显减少（P < 0.01）。②实验组及对照组各时段血中的皮质醇浓度比较无明显差异（P > 0.05）。③实验组造模后120 d病理性瘢痕中成纤维细胞的数量少于对照组。 结论：含有去炎松-A 1 mg/cm2 的固体脂质纳米颗粒卡波姆凝胶透皮吸收对瘢痕有治疗作用，且长期应用血液中的皮质醇浓度不升高，能预防糖皮质激素治疗瘢痕的副作用。     

钙—钙调蛋白与蛋白激酶C在底物共享结构域中的聚集及其意义

本文从以下几个方面较为系统地阐述了钙-钙调蛋白（Ca^2 -CaM）和蛋白激酶C（PKCs）在底物的共享结构域中聚集现象的研究现状：①CaM贮存蛋白（如神经颗粒素NG、神经调节素NM）的分布；②CaM和PKCs到达共享结构域的相对时间；③突触后CaM和PKCs的竞争性聚集。     

动脉粥样硬化病变及其药物治疗措施

动脉粥样硬化是慢性、弥漫性,累及血管、代谢和免疫的多系统炎症性疾病,可以出现各种局部和全身的表现,是缺血性心、脑血管病的重要原因。保护血管内皮细胞、控制炎症、调节血脂、抗氧化以及抗血小板治疗则成为抑制动脉粥样硬化病变形成和稳定斑块的主要策略。     

纳米羟基磷灰石颗粒对巨噬细胞DNA的损伤

目的：纳米颗粒由于其特殊的尺寸效应，会对细胞内处于纳米尺寸级的RNA、DNA和蛋白质等生物大分子直接产生不良影响，使生物体受到损害。因此，从分子水平上探讨纳米羟基磷灰石颗粒对细胞DNA损伤的相关基因或蛋白的影响具有重要的科学意义。 方法：实验于2005-12/2006-12在上海生物材料研究测试中心完成。①实验材料：纳米羟基磷灰石颗粒由中科院上海硅酸盐所提供，粒径大小为30～80 nm。300 W/40 kHz的超声条件下，用含体积分数为0.1小牛血清的RPMI-1640振荡纳米颗粒，制备成终浓度为1 g/L的悬浮液，4 ℃保存1周。②实验方法：选用RT-PCR的技术，通过原代培养大鼠腹腔巨噬细胞，在分子水平上检测纳米羟基磷灰石颗粒对DNA损伤通路中P53、P21、gadd45以及HSP70这些关键蛋白转录水平的影响。 结果：通过mRNA水平的检测，发现P53、P21及HSP70的表达均随着纳米羟基磷灰石颗粒浓度的增加而升高，并在100 mg/L条件下P53、P21及HSP70有显著性表达（P < 0.05），而当纳米羟基磷灰石颗粒达到200 mg/L，只有P21的表达反而有所降低，同时各浓度的纳米羟基磷灰石颗粒对gadd45表达无明显影响（P > 0.05）。 结论：实验证实了100 mg/L 纳米羟基磷灰石颗粒可以引起DNA的明显损伤。并且当纳米羟基磷灰石颗粒浓度达到200 mg/L时，受损的DNA已不易被修复。同时，P53和HSP70可成为评价纳米羟基磷灰石颗粒安全性较为灵敏的指标。     

干细胞中的骨形态发生蛋白信号转导机制★

学术背景：骨形态发生蛋白属于TGF-β超家族的一类多功能分泌型信号分子，通过信号级联传导调节胚胎形态特征、组织器官的发育以及生殖细胞的分化；还能促进干细胞沿不同的方向分化与凋亡。骨形态发生蛋白在不同类型的干细胞中，其信号转导途径呈多样化；目前原因还不十分明确，但研究表明可能与受体或其细胞中多重信号的整合作用有关。 目的：综述骨形态发生蛋白信号转导途径在几种类型干细胞中所发挥的作用及其转导机制。 检索策略：由该论文的研究人员应用计算机检索Pubmed数据库 2007-04/07的相关文献，检索词“bone morphogenetic protein，the differentiation and proliferation of stem cell”，并限定文章语言种类为English。共检索到45篇文献，对资料进行初审，纳入标准：①文章所述内容应与骨形态发生蛋白信号转导途径相关。②同一领域选择近期发表或在权威杂志上发表的文章。排除标准：①重复性研究。②Meta分析。 文献评价：文献的来源主要是通过对骨形态发生蛋白信号转导途径方面内容进行汇总分析。所选用的31篇文献中，2篇为综述，其余均为临床或基础实验研究。 资料综合：①骨形态发生蛋白信号属于激酶转导系统，可通过Smads或p38 MAPK通路传递信号，在转导过程中受多种细胞内外因素的调节。②骨形态发生蛋白信号强弱、时间以及下游信号通路均对早期胚胎干细胞的增殖和分化产生重要影响，可能与Wnts信号通路等多重级联交互作用有关。③骨形态发生蛋白信号可促进神经干细胞向神经元和神经胶质细胞分化，抑制胰脏祖细胞的分化。骨形态发生蛋白4通过抑制分化作用和阻止其前体细胞的增殖这两方面来调节毛细胞数量，还能促进眼胚胎细胞的增殖与凋亡。骨形态发生蛋白和Nodal信号能通过与膜受体竞争性结合调节中胚层祖细胞的发育、增殖与分化。 结论：骨形态发生蛋白信号通路受细胞内外多种因素调控，能调控各种来源干细胞的分化与增殖，调节靶基因的转录。但其只是干细胞特性的调节因子，不是干细胞增殖与分化的标记物。目前，骨形态发生蛋白信号转导与整合作用的细胞学机制、信号转导作用的时间与空间位置等问题还有待进一步研究。     

胰岛素样生长因子Ⅰ抑制氧化型低密度脂蛋白诱导内皮细胞凋亡的体外试验*☆

目的：胰岛素样生长因子Ⅰ作为重要的促细胞生长因子之一，其对内皮细胞凋亡影响的报道不多。实验拟验证和探讨胰岛素样生长因子Ⅰ对氧化型低密度脂蛋白诱导人脐静脉内皮细胞凋亡的抑制作用及可能机制。 方法：实验于2006-12/2007-07在华中科技大学同济医学院协和医院心血管疾病研究所完成。①实验材料及分组处理：取人新鲜脐带（产妇或家属签署知情同意书）分离培养人脐静脉内皮细胞,分为: 胰岛素样生长因子Ⅰ组(1×10-9 mmol/L)、氧化型低密度脂蛋白(200 mg/L)+胰岛素样生长因子Ⅰ组(1×10-9 mmol/L)、氧化型低密度脂蛋白(200 mg/L)组、正常对照组。分别在细胞培养24 h后加入。②实验评估：采用四甲基偶氮唑盐法测定细胞活力；DAPI细胞核荧光染色法观察细胞凋亡的形态学变化及细胞凋亡率的测定；并进行内皮细胞 caspase-3活性的检测。 结果：①氧化型低密度脂蛋白可明显抑制人脐静脉内皮细胞增殖，胰岛素样生长因子Ⅰ与氧化型低密度脂蛋白共同加入后，细胞增殖率明显上升（P < 0.05）。②氧化型低密度脂蛋白可诱导人脐静脉内皮细胞发生凋亡，而加入胰岛素样生长因子Ⅰ刺激后细胞凋亡率降低（P < 0.05）。③caspase-3活性检测表明与对照组相比，氧化型低密度脂蛋白能明显上调caspase-3的表达，而胰岛素样生长因子Ⅰ+氧化型低密度脂蛋白组caspase-3活性则降低（P < 0.05）。 结论：胰岛素样生长因子Ⅰ对氧化型低密度脂蛋白诱导的人脐静脉内皮细胞凋亡具有抑制作用，可能与其下调caspase-3蛋白表达有关。     

Proprotein convertase subtilisin/kexin type 9 (PCSK9) in lipid metabolism,atherosclerosis and ischemic stroke

Proprotein convertase subtilisin/kexin 9 (PCSK9) is the ninth member of the proprotein convertase family. It is an important regulator of cholesterol metabolism. PCSK9 can bind to low-density lipoprotein receptors (LDLRs) and induce the degradation of these receptors through the endosome/lysosome pathway, thus decreasing the LDLR levels on the cell surface of hepatocytes, resulting in increased serum low-density lipoprotein cholesterol (LDL-C) concentrations. Recent studies have found that gene polymorphisms of PCSK9 are associated with hypercholesterolemia, risk of atherosclerosis, and ischemic stroke. Furthermore, monoclonal antibodies, peptide mimetics, small molecule inhibitors and gene silencing agents that are associated with PCSK9 are some of the newer pharmaceutical therapeutic strategies and approaches for lowering serum LDL-C levels. In this review, we will discuss recent advances in PCSK9 research, which show that PCSK9 is correlated with lipid metabolism, atherosclerosis, and, in particular, ischemic stroke. We will also discuss the current state of PCSK9 therapeutics and their potential in modulating these diseases.     

Alzheimer's disease: cerebrovascular dysfunction, oxidative stress, and advanced clinical therapies

Many lines of independent research have provided convergent evidence regarding oxidative stress, cerebrovascular disease, dementia, and Alzheimer's disease (AD). Clinical studies spurred by these findings engage basic and clinical communities with tangible results regarding molecular targets and patient outcomes. Focusing on recent progress in characterizing age-related diseases specifically highlights oxidative stress and mechanisms for therapeutic action in AD. Oxidative stress has been investigated independently for its relationship with aging and cardiovascular and neurodegenerative diseases and provides evidence of shared pathophysiology across these conditions. The mechanisms by which oxidative stress impacts the cerebrovasculature and blood-brain barrier are of critical importance for evaluating antioxidant therapies. Clinical research has identified homocysteine as a relevant risk factor for AD and dementia; basic research into molecular mechanisms associated with homocysteine metabolism has revealed important findings. Oxidative stress has direct implications in the pathogenesis of age-related neurodegenerative diseases and careful scrutiny of oxidative stress in the CNS has therapeutic implications for future clinical trials. These mechanisms of dysfunction, acting independently or in concert, through oxidative stress may provide the research community with concise working concepts and promising new directions to yield new methods for evaluation and treatment of dementia and AD.     

Oxidative stress,antioxidant defenses,and schizophrenia

Schizophrenia is a complex neuropsychiatric disorder with a prevalence of nearly 1% of the world population. Accumulating evidence suggests that increase in production of reactive oxygen species (ROS) along with decrease in antioxidants and antioxidant enzymes (superoxide dismutase, glutathione peroxidase and catalase) may be closely associated with the pathogenesis of schizophrenia. Genes associated with glutamate transmission, dopamine transmission, synaptic plasticity, mitochondrial function, oxidative stress, lipid metabolism, and neuroinflammation have been closely linked to schizophrenia. Proteins encoded by many of the above genes affect the level of ROS, and lipid mediators that regulate signaling in the brain through cross‐talk among glutamate, dopamine, and eicosanoid receptors. Under physiological conditions, this refines the communication between neurons, glial cells and vascular cells, but in schizophrenia, the cross‐talk might initiate and promote oxidative stress‐mediated abnormal neuronal signaling responsible for symptoms of the disease.     

Antioxidant Effects of Statins in Patients with Atherosclerotic Cerebrovascular Disease

Background and Purpose

Oxidative stress is involved in the pathophysiological mechanisms of stroke (e.g., atherosclerosis) and brain injury after ischemic stroke. Statins, which inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, have both pleiotropic and low-density lipoprotein (LDL)-lowering properties. Recent trials have shown that high-dose statins reduce the risk of cerebrovascular events. However, there is a paucity of data regarding the changes in the oxidative stress markers in patients with atherosclerotic stroke after statin use. This study evaluated changes in oxidative stress markers after short-term use of a high-dose statin in patients with atherosclerotic stroke.

Methods

Rosuvastatin was administered at a dose of 20 mg/day to 99 patients who had suffered an atherosclerotic stroke and no prior statin use. Blood samples were collected before and 1 month after dosing, and the serum levels of four oxidative stress markers-malondialdehyde (MDA), oxidized LDL (oxLDL), protein carbonyl content (PCO), and 8-hydroxy-2''-deoxyguanosine (8-OHdG)-were evaluated to determine the oxidation of MDA and lipids, proteins, and DNA, respectively, at both of those time points.

Results

The baseline levels and the degrees of reduction after statin use differed among the oxidative stress markers measured. MDA and PCO levels were associated with infarct volumes on diffusion-weighted imaging (r=0.551, p<0.05, and r=0.444, p=0.05, respectively). Statin use decreased MDA and oxLDL levels (both p<0.05) but not the PCO or 8-OHdG level. While the reduction in MDA levels after statin use was not associated with changes in cholesterol, that in oxLDL levels was proportional to the reductions in cholesterol (r=0.479, p<0.01), LDL (r=0.459, p<0.01), and apolipoprotein B (r=0.444, p<0.05).

Conclusions

The impact of individual oxidative stress markers differs with time after ischemic stroke, suggesting that different oxidative markers reflect different aspects of oxidative stress. In addition, short-term use of a statin exerts antioxidant effects against lipid peroxidation via lipid-lowering-dependent and -independent mechanisms, but not against protein or DNA oxidation in atherosclerotic stroke patients.     

Oxidative stress, endothelial dysfunction and cerebrovascular disease

Endothelial dysfunction is a marker of atherosclerosis and contributes to the atherogenic process and the development of atherothrombotic complications. Oxidative stress has been implicated in the development of endothelial dysfunction through alterations of the nitric oxide metabolism. A number of evidence suggests a role for phagocytic-cell-mediated oxidative stress in diminished nitric oxide availability that is present in patients with atherosclerotic risk factors such as arterial hypertension. Thus, the combination of an excessive production of reactive oxygen species, namely superoxide anion, with an impaired antioxidant defense capacity leading to oxidative stress may facilitate the development and progression of atherosclerosis. Findings from recent clinical studies suggest that this mechanism can be operative in patients with cerebrovascular disease. This view may increase our capabilities to understand the pathophysiology of cerebrovascular disease, as well as to stimulate the design of new therapeutic strategies aimed to prevent and control the atherosclerotic process in patients presenting this condition.     

Oxidative stress does not appear to be involved in the aetiology of Friedreich's ataxia

The purpose of this study was to investigate the hypothesis that the gene for Friedreich's ataxia (FA) may be involved in the metabolism of α-tocopherol (vitamin E) or in other antioxidant systems. Concentrations of α-tocopherol, parameters of endogenous lipid peroxidation and susceptibility to in vitro oxidative stress were measured in neural tissues from four patients with FA and four controls. In general there were no significant differences in any of the parameters studied, although the brainstem whole homogenate from the FA patients was significantly (p < 0.02) less susceptible to in vitro oxidative stress than control material. These results, therefore, do not support the suggestion that abnormal metabolism of α-tocopherol or increased oxidative stress is involved in the aetiology of FA.     

Oxidative stress in schizophrenia - focusing on the main markers

Oxidative stress is the condition arising from imbalance between toxic reactive oxygen species and antioxidant systems. It is believed that increased oxidative stress may be relevant to the pathophysiology of schizophrenia. In this way, the main markers of the lipid peroxidation processes include 4-hydroxynonenal and malondialdehyde. On the other side, the potential toxicity of free radicals is counteracted by a number of cytoprotective antioxidant enzymes that limit the damage, such as superoxide dismutase and glutathione peroxidase. However, the reports regarding the status of oxidative stress markers schizophrenia are very inconsistent, with various authors stating both increased and decreased activities of the main antioxidant enzymes, while others did not observe any significant modifications, as compared to control groups. Similar aspects were also reported in the case of the lipid peroxidation markers, although in here the contradictions are much more reduced than in the case of the antioxidant defences. It is generally believed that the equivocal results mentioned above may be due to different tissues studies, different species or the administrated treatment and the duration of the disease/treatment. In this context, in the present paper we were interested to review some studies regarding the oxidative stress status in patients and animal models of schizophrenia, by referring mainly to antioxidant enzymes and lipid peroxidation markers.     

Oxidant and antioxidant parameters in the treatment of meningitis

The aim of this study was to assess the effects of meningitis treatment on the serum and cerebrospinal-fluid oxidant and antioxidant status in children with bacterial meningitis. Forty children with bacterial meningitis, at ages ranging from 4 months to 12 years (mean age, 4 years), were enrolled in the study. Within 8 hours after admission (before treatment) and 10 days after clinical and laboratory indications of recovery (after treatment), cerebrospinal fluid and venous blood were collected. Thirty-seven healthy children (mean age, 4 years) were enrolled as control subjects, and only venous blood was collected. Serum total oxidant status, lipid hydroperoxide, oxidative stress index, uric acid, albumin, and ceruloplasmin levels were lower in the patient group after treatment (P<0.05). Serum total antioxidant capacity levels, vitamin C, total bilirubin, and catalase concentrations were not significantly altered by treatment (P>0.05). However, cerebrospinal fluid total oxidant status, lipid hydroperoxide, and oxidative stress index levels were higher, and cerebrospinal fluid total antioxidant capacity levels were lower after treatment than before treatment (P<0.05). In conclusion, we demonstrated that serum oxidative stress was lower, and cerebrospinal fluid oxidative stress was higher, after rather than before treatment in children with bacterial meningitis.     

d-Serine administration provokes lipid oxidation and decreases the antioxidant defenses in rat striatum

The present work investigated the effects of intrastriatal administration of d-serine on relevant parameters of oxidative stress in striatum of young rats. d-Serine significantly induced lipid peroxidation, reflected by the significant increase of thiobarbituric acid-reactive substances, and significantly diminished the striatum antioxidant defenses, as verified by a decrease of the levels of reduced glutathione and total antioxidant status. Finally, d-serine inhibited superoxide dismutase activity, without altering the activities of glutathione peroxidase and catalase. In contrast, this d-amino acid did not alter sulfhydryl oxidation, a measure of protein oxidative damage. The present data indicate that d-serine in vivo administration induces lipid oxidative damage and decreases the antioxidant defenses in the striatum of young rats. Therefore, it is presumed that this oxidative stress may be a pathomechanism involved at least in part in the neurological damage found in patients affected by disorders in which d-serine metabolism is compromised, leading to altered concentrations of this d-amino acid.