Targeting the Immune System in Atherosclerosis: JACC State-of-the-Art Review

Atherosclerosis has long been known as an inflammatory disease. However, whether targeting inflammation improves outcomes was unproven until the recent results of CANTOS (Canakinumab Anti-Inflammatory Thrombosis Outcomes Study). In this review, we reflect on why it has taken a long time to prove the inflammatory hypothesis of atherosclerosis and derive important lessons for the future. In particular, we discuss the off-target immune-modulatory effects of approved cardiovascular therapies, review the attempted anti-inflammatory therapies including the recently published CIRT (Cardiovascular Inflammation Reduction Trial), and discuss the likely reasons for their failures. We further build on CANTOS to review the immune-modulatory therapies for atherosclerosis currently in trials, and discuss the likelihood of their added value as well as the potential hazard associated with their use. We finally argue for a critical approach to the use of animal models, coupled with the use of humans as model organisms to accelerate the identification of the most appropriate targets.     

基于Akt/ERK探讨丹蒌片对主动脉平滑肌细胞增殖、迁移和凋亡的影响＊

目的 观察丹蒌片对同型半胱氨酸（homocysteine，Hcy）诱导的兔主动脉血管平滑肌细胞（rabbit aortic smooth muscle cell，RASMC）增殖、迁移和凋亡的影响，并探讨其与Akt及ERK信号通路的关系。方法 培养RASMC，建立Hcy诱导RASMC增殖模型，实验分为空白组、Hcy组、丹蒌片组、瑞舒伐他汀组（即可定组）、丹蒌片联合瑞舒伐他汀组（即混合组），后三组分别给于丹蒌片、瑞舒伐他汀及丹蒌片联合瑞舒伐他汀含药血清。作用24 h后，Cell Titer-Glo法测细胞增殖，Transwell法测细胞迁移，流式细胞仪Annexin V/PI双染法测细胞凋亡率，蛋白印迹法（Western blot）测信号通路相关蛋白Akt和ERK总蛋白及磷酸化蛋白表达量。结果 ①与空白组相比，Hcy组细胞增殖和迁移显著增加（P < 0.01），凋亡率显著降低（P < 0.01）；与Hcy组相比，三种含药血清组细胞增殖和迁移明显减少（P < 0.01），凋亡率明显增加（P < 0.01）；其中混合组增殖和迁移较丹蒌片组和可定组明显降低（P < 0.01），凋亡率更高（P < 0.01）；与可定组比，丹蒌片组增殖略高，但差异均无统计学意义（P > 0.05），丹蒌片组细胞迁移数明显多于可定组（P < 0.05），凋亡率明显低于可定组（P < 0.05）。②各组Akt及ERK总蛋白表达水平无明显变化（P > 0.05）；与空白组比较，Hcy组p-Akt及p-ERK蛋白表达量均显著上调（P < 0.01）；与Hcy组相比，三种含药血清组p-Akt及p-ERK蛋白表达量明显下调（P < 0.01）；其中混合组的p-Akt及p-ERK蛋白表达较丹蒌片组和可定组进一步下降（P < 0.01）；与可定组比，丹蒌片组p-Akt及p-ERK蛋白表达量增加，但差异无统计学意义（P > 0.05）。结论 丹蒌片可拮抗Hcy诱导的兔动脉血管平滑肌细胞增殖和迁移，促进其凋亡，其作用可能与上调p-Akt及p-ERK信号通路蛋白有关。     

Lack of vitamin D receptor causes stress-induced premature senescence in vascular smooth muscle cells through enhanced local angiotensin-II signals

Objectives

The inhibition of the renal renin-angiotensin system by the active form of vitamin D contributes to the cardiovascular health benefits of a normal vitamin D status. Local production of angiotensin-II in the vascular wall is a potent mediator of oxidative stress, prompting premature senescence. Herein, our objective was to examine the impact of defective vitamin D signalling on local angiotensin-II levels and arterial health.

Methods

Primary cultures of aortic vascular smooth muscle cells (VSMC) from wild-type and vitamin D receptor-knockout (VDRKO) mice were used for the assessment of cell growth, angiotensin-II and superoxide anion production and expression levels of cathepsin D, angiotensin-II type 1 receptor and p57^Kip2. The in vitro findings were confirmed histologically in aortas from wild-type and VDRKO mice.

Results

VSMC from VDRKO mice produced more angiotensin-II in culture, and elicited higher levels of cathepsin D, an enzyme with renin-like activity, and angiotensin-II type 1 receptor, than wild-type mice. Accordingly, VDRKO VSMC showed higher intracellular superoxide anion production, which could be suppressed by cathepsin D, angiotensin-II type 1 receptor or NADPH oxidase antagonists. VDRKO cells presented higher levels of p57^Kip2, impaired proliferation and premature senescence, all of them blunted upon inhibition of angiotensin-II signalling. In vivo studies confirmed higher levels of cathepsin D, angiotensin-II type 1 receptor and p57^Kip2 in aortas from VDRKO mice.

Conclusion

The beneficial effects of active vitamin D in vascular health could be a result of the attenuation of local production of angiotensin-II and downstream free radicals, thus preventing the premature senescence of VSMC.     

dNK derived IFN-γ mediates VSMC migration and apoptosis via the induction of LncRNA MEG3: A role in uterovascular transformation

IntroductionAppropriate spiral artery remodeling is critical for successful fetal development and pregnancy outcomes. The vascular smooth muscle cell (VSMC) loss and separation, involving cell apoptosis and migration, plays an important role in this process. Decidual natural killer cells (dNK)-derived interferon gamma (IFN-γ), a key regulator of uterine arterial remodeling, can facilitate separation of VSMC layers, however, the specific mechanisms of it action are unknown. Long non-coding RNA MEG3 functions as tumor suppressor by regulating apoptosis and migration. Moreover, IFN-γ has been shown to influence cell vitality through regulating MEG3 expression. However, the functional role of dNK derived IFN-γ and MEG3 on VSMC viability, as well as the relationship between IFN-γ and MEG3 in VSMCs, has not been completely elaborated.MethodsThe up-regulation strategies and reagent treatment were employed to detect the effects of MEG3 and dNK/IFN-γ on VSMC proliferation, apoptosis and migration. At the same time, MEG3, p53 and matrix metalloproteinase 2 (MMP-2) expressions were investigated.Results: dNK/IFN-γ treatment led to up-regulation of MEG3 expression in VSMCs. Both MEG3 over-expression and dNK/IFN-γ treatment inhibited VSMC proliferation, stimulated VSMC migration and resulted in a small but significant induction of VSMC apoptosis, as well as promoted p53 and MMP-2 expression in VSMCs.DiscussionMEG3 is regulated by dNK-derived IFN-γ and regulates VSMC migration and apoptosis. Therefore, it may be an important positive regulator in VSMC loss from the maternal uterine spiral arteries during vascular transformation.     

Natural History of Thoracic Aortic Aneurysms: Size Matters,Plus Moving Beyond Size

Thoracic aortic aneurysms (TAAs) are a prevalent and deadly disease that, without diagnosis and treatment, eventuates in life-threatening aortic dissection or rupture. While TAAs normally grow in an indolent manner, once a certain size (a “hinge point”) is reached, the risk of dissection, rupture, and death increases dramatically. By virtue of their common clinical “silence,” many TAAs are not diagnosed until such complications occur. While size is a helpful criterion for intervention, there is a need for parameters and markers besides aortic aneurysm size for use in diagnosing and monitoring TAAs so as to prevent natural complications of this disease.     

p38MAPK反义寡核苷酸对鼠血管平滑肌细胞增殖的影响

目的：探讨丝裂素活化蛋白激酶p38(p38mitogen—activated protein kinase，p38MAPK)反义寡聚脱氧核苷酸(antisense oliodeoxynucleotide，AODN)对血管平滑肌细胞增殖的影响。方法：培养大鼠胸主动脉平滑肌细胞。通过脂质体帮染p38MAPK AODN到血管平滑肌细胞(VMSC)。另设p38MAPK正义寡聚脱氧核苷酸(SODN)对照组和空白对照组。用流式细胞仪检测细胞增殖。结果：AODN明显抑制血管紧张素I刺激的血管平滑肌细胞增殖(P＜0.05～＜0．01)，其抑制作用呈剂量依赖性。结论：p38MAPK反义寡聚脱氧核苷酸能抑制大鼠的VSMC增殖，提示VSMC增殖与p38信号途径有关。     

Protein kinase C isoforms in atherosclerosis: Pro- or anti-inflammatory?

Atherosclerosis is a pathologic condition caused by chronic inflammation in response to lipid deposition in the arterial wall. There are many known contributing factors such as long-term abnormal glucose levels, smoking, hypertension, and hyperlipidemia. Under the influence of such factors, immune and non-immune effectors cells are activated and participate during the progression of atherosclerosis. Protein kinase C (PKC) family isoforms are key players in the signal transduction pathways of cellular activation and have been associated with several aspects of the atherosclerotic vascular disease. This review article summarizes the current knowledge of PKC isoforms functions during atherogenesis, and addresses differential roles and disputable observations of PKC isoforms. Among PKC isoforms, both PKCβ and PKCδ are the most attractive and potential therapeutic targets. This commentary discusses in detail the outcomes and current status of clinical trials on PKCβ and PKCδ inhibitors in atherosclerosis-associated disorders like diabetes and myocardial infarction. The risk and benefit of these inhibitors for clinical purposes will be also discussed. This review summarizes what is already being done and what else needs to be done in further targeting PKC isoforms, especially PKCβ and PKCδ, for therapy of atherosclerosis and atherosclerosis-associated vasculopathies in the future.     

氯吡格雷通过上调miR-145表达抑制VSMC增殖的机制研究

目的 本研究旨在探究miR-145是否对血管平滑肌细胞(VSMC)的增殖起调控作用,以及氯吡格雷如何通过调控CD40来发挥其消炎作用,以期为氯吡格雷的药用作用发挥提供新的理论依据.方法 实验分组为①DMSO组,即溶剂对照组;②TNF-α组;③miR-145抑制剂对照组;④氯吡格雷组;⑤miR-145抑制剂+氯吡格雷组.并通过EdU标记检测细胞增殖;qRT-PCR用于检测miR-145,CD40和VSMC中Calponin mRNA的表达;Western blot检测CD40的蛋白表达水平;通过ELISA检测细胞培养物上清液中IL-6的水平.结果 与氯吡格雷组相比,miR-145抑制剂+氯吡格雷组的Calponin mRNA水平降低(P <0.01);与DMSO组相比,TNF-α组的miR-145 mRNA水平下降(P<0.01);与TNF-α组相比,氯吡格雷组的miR-145 mRNA水平上升(P<0.01);与氯吡格雷组相比,miR-145抑制剂+氯吡格雷组的miR-145 mRNA水平下降(P<0.01).miR-145抑制剂对照组不影响CD40的水平;与DMSO组相比,TNF-α组的CD40 mRNA水平上升(P<0.01);与TNF-α组相比,氯吡格雷组的CD40 mRNA水平下降(P<0.01);与氯吡格雷组相比,miR-145 抑制剂+氯吡格雷组的CD40 mRNA水平上升(P<0.01).TNF-α组上清液中IL-6的水平高于DMSO组(P<0.01);氯吡格雷组中IL-6水平低于TNF-α组(P<0.01);miR-145抑制剂+氯吡格雷组IL-6的水平高于氯吡格雷组(P<0.01).结论 氯吡格雷通过抑制CD40的表达,诱导miR-145抑制VSMC细胞增殖并发挥消炎作用.     

全反式维甲酸对兔颈动脉粥样硬化性狭窄中平滑肌细胞凋亡及其机制的研究

目的观察全反式维甲酸（ATRA）对兔颈动脉粥样硬化性狭窄后平滑肌细胞凋亡的影响。方法新西兰兔40只，随机分为3组：对照组（CON）、手术组（SUR）、治疗组（TRE），均给予高脂饮食，两周后手术组和治疗组用空气干燥法建立颈动脉粥样硬化模型，治疗组于术前给予全反式维甲酸灌胃。分别于术后两周、四周处死动物取病变处血管，HE染色后观察观察内膜增生情况，并用TUNEL法检测细胞凋亡、免疫组化检测凋亡抗原基因Fas。结果形态学观察显示内膜增生程度由强到弱为：SUR〉TRE〉CON。在治疗组凋亡细胞TUNEL阳性细胞数最多，Fas表达最明显。结论ATRA具有诱导平滑肌细胞凋亡的作用，在一定程度上抑制血管内膜增生，抑制血管损伤后再狭窄，其机制可能是通过FAS／FASL途径。