Nitric oxide (NO) derived from endothelial NO synthase (eNOS) is regarded as a protective factor against atherosclerosis. Therefore, augmentation of eNOS expression or NO production by pharmacological intervention is postulated to inhibit atherosclerosis. We crossed eNOS-overexpressing (eNOS-Tg) mice with atherogenic apoE-deficient (apoE-KO) mice to determine whether eNOS overexpression in the endothelium could inhibit the development of atherosclerosis. After 8 weeks on a high-cholesterol diet, the atherosclerotic lesion areas in the aortic sinus were unexpectedly increased by more than twofold in apoE-KO/eNOS-Tg mice compared with apoE-KO mice. Also, aortic tree lesion areas were approximately 50% larger in apoE-KO/eNOS-Tg mice after 12 weeks on a high-cholesterol diet. Expression of eNOS and NO production in aortas from apoE-KO/eNOS-Tg mice were significantly higher than those in apoE-KO mice. However, eNOS dysfunction, demonstrated by lower NO production relative to eNOS expression and enhanced superoxide production in the endothelium, was observed in apoE-KO/eNOS-Tg mice. Supplementation with tetrahydrobiopterin, an NOS cofactor, reduced the atherosclerotic lesion size in apoE-KO/eNOS-Tg mice to the level comparable to apoE-KO mice, possibly through the improvement of eNOS dysfunction. These data demonstrate that chronic overexpression of eNOS does not inhibit, but accelerates, atherosclerosis under hypercholesterolemia and that eNOS dysfunction appears to play important roles in the progression of atherosclerosis in apoE-KO/eNOS-Tg mice.

Abstract-Monocyte/macrophage infiltration to the arterial wall is an initial step in atherosclerosis, and monocyte chemoattractant protein-1 (MCP-1) is thought to play a central role in the recruitment of these cells. In the present study, we examined the role of local expression of MCP-1 at the vessel wall in the initiation and development of atherosclerosis. We transfected the cDNA encoding rat MCP-1 into the vessel wall of the rabbit carotid artery with the use of the hemagglutinating virus of Japan (HVJ)-liposome method. The rabbits were divided into the following groups:(1) those fed normal chow and transfected with MCP-1-HVJ, (2) those fed a high cholesterol diet (1% cholesterol) and transfected with MCP-1-HVJ, and (3) those fed a high cholesterol diet and transfected with control-HVJ. Prescribed diets were started 2 weeks before transfection and were continued for another 2 weeks. In group 1, vascular lesion formation was not found, and anti-rabbit monocyte/macrophage antibody (RAM-11) staining for monocytes/macrophages was negative, although anti-rat MCP-1 antibody (R-17) staining for rat MCP-1 was positive mainly in endothelial cells. Cholesterol feeding increased plasma cholesterol levels to 1801Ϯ444 mg/dL in group 2. In group 2, all rabbits displayed neointimal formation with infiltration of RAM-11-positive cells, and a part of the lesion was also positive for Sudan III lipid staining. In group 3, hypercholesterolemia did not induce the infiltration of monocytes/ macrophages and subsequent lesion formation in the vessel wall despite definite upregulation of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 on the endothelium. To initiate atherosclerotic changes, local MCP-1 overexpression at the vessel is not sufficient, and activation of other factors induced by hypercholesterolemia is required. Key Words: monocyte chemoattractant protein-1 Ⅲ hypercholesterolemia Ⅲ atherosclerosis M onocytes/macrophages play an essential role in the initiation and progression of atherosclerosis. Foam cells accumulating cholesterol ester are found in early atherosclerotic lesions, and these cells are believed to be derived mainly from circulating monocytes/macrophages. 1,2 Among many factors involved in the recruitment of monocytes/macrophages, recent studies have highlighted monocyte chemoattractant protein-1 (MCP-1). 3,4 MCP-1 is highly expressed in the macrophage-rich area of the atherosclerotic lesions in human and animal models. 3 MCP-1 is induced by oxidized lipoproteins and proinflammatory cytokines, such as interleukin-1␤ and tumor necrosis factor-␣, 5,6 and its expression and secretion from vascular cells have been demonstrated to account for the increased monocyte chemotactic activity. 7 These findings suggest that MCP-1 plays an important role in the initiation of atherosclerotic lesion formation. However, chemotactic factors other than MCP-1 are also involved in monocyte recruitment and the subsequent lesion formation in atherogenesis. 8 On the other hand, MCP-1 in transgenic mice in ...

Nitric oxide (NO) derived from endothelial NO synthase (eNOS) is regarded as a protective factor against atherosclerosis. Therefore, augmentation of eNOS expression or NO production by pharmacological intervention is postulated to inhibit atherosclerosis. We crossed eNOS-overexpressing (eNOS-Tg) mice with atherogenic apoE-deficient (apoE-KO) mice to determine whether eNOS overexpression in the endothelium could inhibit the development of atherosclerosis. After 8 weeks on a high-cholesterol diet, the atherosclerotic lesion areas in the aortic sinus were unexpectedly increased by more than twofold in apoE-KO/eNOS-Tg mice compared with apoE-KO mice. Also, aortic tree lesion areas were approximately 50% larger in apoE-KO/eNOS-Tg mice after 12 weeks on a high-cholesterol diet. Expression of eNOS and NO production in aortas from apoE-KO/eNOS-Tg mice were significantly higher than those in apoE-KO mice. However, eNOS dysfunction, demonstrated by lower NO production relative to eNOS expression and enhanced superoxide production in the endothelium, was observed in apoE-KO/eNOS-Tg mice. Supplementation with tetrahydrobiopterin, an NOS cofactor, reduced the atherosclerotic lesion size in apoE-KO/eNOS-Tg mice to the level comparable to apoE-KO mice, possibly through the improvement of eNOS dysfunction. These data demonstrate that chronic overexpression of eNOS does not inhibit, but accelerates, atherosclerosis under hypercholesterolemia and that eNOS dysfunction appears to play important roles in the progression of atherosclerosis in apoE-KO/eNOS-Tg mice

Background and Purpose-Recent clinical studies suggest that 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) exert protective effects against nonhemorrhagic stroke. In a murine cerebral ischemia model produced by occlusion of the middle cerebral artery, statins were shown to reduce infarct size. However, the effect of statins on hypertension-based stroke is unknown. The purpose of this study is to clarify the effect of a statin on stroke in stroke-prone spontaneously hypertensive rats (SHR-SP), in which both cerebral hemorrhage and infarction occur. Methods-We treated SHR-SP chronically from 4 weeks of age with cerivastatin (2 mg/kg per day by gavage) or vehicle.The physiological parameters, the incidence of stroke-associated symptoms, and mortality were assessed. Results-At 14 weeks of age, the incidence (13Ϯ3% versus 37Ϯ8%; PϽ0.01) and the size of stroke (1.6Ϯ0.2 versus 2.2Ϯ0.1 arbitrary units; PϽ0.01) were significantly decreased by cerivastatin, although blood pressure and plasma cholesterol levels were not different. Moreover, stroke-associated symptoms and early mortality of SHR-SP were markedly reduced in the statin-treated group (mortality at the age of 15 weeks: 15% versus 50%; PϽ0.05). Statin treatment significantly reduced superoxide production from nonstroke parenchyma of brain and infiltration of inflammatory cells to the stroke lesions. Conclusions-Our data show that a high dose of statin exerts protection against hypertension-based stroke and ameliorates the disease severity via inhibition of superoxide production and modulation of inflammation in brain.

SummaryEribulin mesylate (Halaven™, E7389) is a synthetic analog of the marine natural product halichondrin B that acts via a mechanism distinct from conventional tubulin-targeted agents. This Phase I study (clinicaltrials.gov identifier: NCT00326950) was the first to investigate eribulin mesylate in Japanese patients. The study determined the recommended dose, MTD, DLTs, safety, pharmacokinetics, and antitumor activity of eribulin administered on Days 1 and 8 of a 21-day cycle in Japanese patients with advanced solid tumors. Fifteen patients received eribulin mesylate 0.7–2.0 mg/m2 as a 2- to 10-min intravenous injection. Neutropenia was the principal DLT. DLTs were observed in two of six patients treated at 1.4 mg/m2, and in all three patients at 2.0 mg/m2. The recommended dose was 1.4 mg/m2 and the MTD was 2.0 mg/m2. Neutropenia (67%), lymphocytopenia (20%), febrile neutropenia (33%), and fatigue (13%) were the most common grade 3 or 4 toxicities. Eribulin exhibited triphasic pharmacokinetics with a long terminal half-life, high volume of distribution, and low urinary clearance. Three patients achieved partial responses (two with NSCLC, one with head and neck cancer) at 1.4 mg/m2 dose level. Eribulin mesylate, administered on Days 1 and 8 of a 21-day cycle, exhibits manageable tolerability at 1.4 mg/m2. DLT was neutropenia.