The Inhibitory Effect of Shikonin on the Agonist-Induced Regulation of Vascular Contractility

Shikonin, a natural flavonoid found in the roots of Lithospermum erythrorhizon, has been shown to possess many biological functions. The present study was undertaken to investigate the influence of shikonin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Shikonin significantly relaxed fluoride-, thromboxane A₂- or phorbol ester-induced vascular contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, shikonin significantly inhibited fluoride-induced increases in pMYPT1 levels and phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving the inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1 and the inhibition of MEK activity and the subsequent phosphorylation of ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of shikonin on agonist-induced vascular contraction regardless of endothelial function.     

Administration of the Rho-Kinase Inhibitor Fasudil Before Ischemia or just After Reperfusion,but not 30 min After Reperfusion,Protects the Stunned Myocardium in Swine

OBJECTIVES: We assessed the effect of administration time for fasudil treatment of the stunned myocardium in 40 anesthetized open chest swine. MATERIALS AND METHODS: All swine were subjected to 12 min ischemia followed by reperfusion to generate stunned myocardium. Group A (n = 11) received saline in place of fasudil both before ischemia and after reperfusion. Group B (n = 10) received 30 min intravenous fasudil at a rate of 13 mug/kg/min starting 45 min before ischemia and received saline after reperfusion. Groups C (n = 10) and D (n = 9) received saline before ischemia, and received fasudil at a rate of 13 mug kg(-1) min(-1) starting just before reperfusion in group C and 30 min after reperfusion in group D. In both groups, treatment lasted 30 min. Myocardial contractility was assessed by percent segment shortening (%SS). RESULTS AND DISCUSSION: Three swine in group A, 2 swine in each of groups B and C, and one swine in group D had ventricular fibrillation or tachycardia after reperfusion and were excluded from further analysis. The changes of %SS from baseline at 90 min after reperfusion in groups B and C were 68 +/- 8% and 75 +/- 8%, respectively, which were significantly higher than in group A or D (47 +/- 10% or 43 +/- 8%). CONCLUSION: We conclude that fasudil administered before ischemia or just after reperfusion, but not 30 min after reperfusion, protects the stunned myocardium.     

Rho激酶信号通路在两肾一夹肾性高血压大鼠心肌肥大中的作用及Fasudil干预

目的：了解Rho激酶介导的信号转导通路在两肾一夹（two-kidneys-one-clip,2K1C）肾性高血压大鼠心肌肥大发病机制中的作用以及特异性Rho激酶抑制剂Fasudil干预效应。方法：制备两肾一夹肾性高血压大鼠模型,实验设假手术组、模型组、实验组（Fasudil 10 mg·kg^-1.d^-1腹腔注射）。电子天平称量左心室质量并计算左心室质量与体质量比值;光学显微镜观察心肌组织形态学变化;Western blotting检测肌球蛋白结合亚基磷酸化（phosphorylation of myosin-binding submet,MBS-P）表达作为Rho激酶功能活化标志;RT-PCR检测Rho激酶mRNA表达。结果：术后12周,模型组大鼠出现较显著的心肌肥大（P〈0.01）,心肌组织Rho激酶活性及mRNA表达显著增加（P〈0.01）且Rho激酶活性及mRNA表达与心肌肥大程度间呈显著正相关（P〈0.05）。Rho激酶特异性抑制剂Fasudil在抑制大鼠心肌组织Rho激酶活化和mRNA表达的同时可有效抑制心肌肥大的发展（P〈0.01）。结论：Rho激酶介导的信号转导通路在2K1C肾性高血压大鼠心肌肥大发病机制中可能具有重要作用,Rho激酶特异性抑制剂Fasudil可有效抑制心肌肥大的发展。     

Rho激酶对严重烧伤大鼠血清诱导的肠黏膜上皮细胞调控机制的研究

目的:观察烧伤血清刺激下肠黏膜上皮细胞通透性的变化及Rho激酶信号转导通路所起的作用。方法:常规培养肠黏膜上皮CaCO-2细胞,分为正常对照组、烧伤血清组和烧伤血清6 h Y27632组,以FITC-albumin荧光强度检测法检测人肠黏膜上皮细胞在未烧伤、1、2、6、12、24 h时相点通透性变化指标;采用Western blot法检测人肠黏膜上皮细胞中肌球蛋白轻链(MLC)、磷酸化MLC(p-MLC)和Rho激酶蛋白水平在6个时相点的变化及烧伤血清6 h Y27632组总MLC、p-MLC及Rho激酶蛋白水平表达。结果:严重烧伤后人肠黏膜上皮细胞通透性明显增加,并呈时相依赖性变化,6~12 h达到最高;p-MLC以及Rho激酶蛋白表达均明显增加。上述蛋白表达的增强可在加入Rho激酶特异性抑制剂Y27632后取消。结论:烧伤大鼠血清能诱导肠黏膜上皮细胞内Rho激酶激活、p-MLC表达增加及肠黏膜通透性增加,抑制Rho激酶活性能逆转这一作用。     

Rho/Rho激酶信号通路在妊娠过程中的作用

Rho通过三磷酸鸟苷(GTP)结合形式和二磷酸鸟苷(GDP)结合形式的转换起着分子开关的作用,调控许多细胞内信号通路。Rho通过激活其下游靶分子Rho激酶调节细胞的黏附、迁移、增殖、收缩等多种生物学行为和功能。近年来,越来越多的研究发现Rho/Rho激酶通路与胚胎种植、妊娠维持及分娩发动密切相关,本文对其在妊娠过程中的作用进行综述。     

Growth factor-induced contraction of human bronchial smooth muscle is Rho-kinase-dependent

Growth factors have been implicated in the pathophysiology of asthma. However, the putative effects of these growth factors on human airway smooth muscle tone are still largely unknown. We performed contraction experiments using human bronchial smooth muscle ring preparations. The growth factor insulin-like growth factor-1 (IGF-1) induced a slowly developing sustained contraction, which was dependent on Rho-kinase, since contraction was almost completely inhibited by (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexane carboxamide (Y-27632; 1 microM). Angiotensin II, a G(q)-coupled receptor agonist which can act as a growth factor as well, induced a biphasic contraction, the sustained phase of which was also almost completely inhibited by Y-27632. We conclude that angiotensin II and IGF-1 induce a Rho-kinase-dependent sustained contraction of human bronchial smooth muscle. Since growth factors are associated with pathophysiological conditions such as asthma, inhibition of Rho-kinase could be effective under these conditions.     

Leads for the treatment of pulmonary hypertension

Background: Knowledge of the causative reasons for pulmonary arterial hypertension, a major category of pulmonary hypertension, has expanded dramatically over the past 10 years. This has led to heightened research across a range of potential new mechanistic approaches and resulted in the identification of further treatment options, together with several promising leads and prototypes. Objective: This review aims to summarise and assess the most relevant research fields, covering key publications and recent patent literature. Methods: Searching revealed in excess of 700 patents claiming uses that relate to pulmonary hypertension. These patents were filtered into key therapeutic approaches based on pharmacological reviews of the pulmonary arterial hypertension field. Results/conclusions: Endothelin antagonists and phosphodiesterase 5 inhibitors have emerged as recently approved treatment options and are proving extremely beneficial. Further new mechanistic approaches have yielded promising leads, some of which have the potential to be disease modifying; notably, tyrosine kinase inhibitors, soluble guanylate cyclase agonists, Rho-kinase inhibitors, vasoactive intestinal peptide analogues and 5-HT antagonists.     

Rho激酶抑制剂在急性冠脉综合征介入治疗中的应用价值

目的应用SYNTAX评分,观察Rho激酶抑制剂法舒地尔对不同评分组的急性冠脉综合征患者介入术后左心功能、一年支架内再狭窄(ISR)和主要心脏不良事件(MACE)的影响。方法入选急性冠脉综合征患者238例,均经冠脉造影证实存在单支以上的病变,均拒绝行冠脉搭桥手术,按随机数字表法分为治疗组(法舒地尔,n=102)和对照组(n=136),根据SYNTAX评分,每组再分为评分低值亚组(0~22分)、评分值中等亚组(23~32分)和评分值高亚组(≥33分),正规冠心病二级预防治疗,并行冠脉造影和支架植入治疗,随访一年,对比观察2组以及2组的亚组间在术中慢血流或无复流、急性或亚急性支架血栓、左心功能、一年内支架内再狭窄率和MACE事件的差异。结果治疗组和对照组观察的各项指标无显著差异(P0.05),2组对应的评分低值组亚组间以及评分中等值亚组间观察的各项指标无显著差异(P0.05);与对照组的评分高值亚组相比,治疗组的评分高值亚组术中发生慢血流或无复流的比例、1年支架内再狭窄比例和MACE事件的发生率显著降低(P0.05),3个月的左心功能明显改善(P0.05)。结论 Rho激酶抑制剂可显著减少SYNTAX评分高值(≥33分)的ACS患者介入术中慢血流或无复流的发生,改善左心功能,并降低1年内支架内再狭窄率和MACE事件的发生率。     

Rho激酶与支架内再狭窄

目的 支架内再狭窄与血管平滑肌分化、迁移,细胞外基质的过度增值所致新生内膜增生密切相关.Rho激酶参与支架置入引起的新生内膜增生的调节.长期抑制Rho激酶的表达可阻止新生内膜的增生,可能成为防止支架内再狭窄的一种方法.     

Rho激酶在高血压中的作用及其与容积调节性氯通道的关系

高血压血管平滑肌重构伴随Rho/Rho激酶通路的激活,抑制Rho激酶可逆转血管平滑肌增生以及血压升高。同时,在高血压中有容积调节性氯通道开放,这与Rho激酶通路激活有关。该文就高血压过程中Rho激酶与容积调节性氯通道的关系做一综述。