Rosuvastatin reduces neointima formation in a rat model of balloon injury

<p>Abstract</p> <p>Background</p> <p>Processes of restenosis, following arterial injury, are complex involving different cell types producing various cytokines and enzymes. Among those enzymes, smooth muscle cell-derived matrix metalloproteinases (MMPs) are thought to take part in cell migration, degrading of extracellular matrix, and neointima formation. MMP-9, also known as gelatinase B, is expressed immediately after vascular injury and its expression and activity can be inhibited by statins. Using an established in vivo model of vascular injury, we investigated the effect of the HMG-CoA reductase inhibitor rosuvastatin on MMP-9 expression and neointima formation.</p> <p>Materials and methods</p> <p>14-week old male Sprague Dawley rats underwent balloon injury of the common carotid artery. Half of the animals received rosuvastatin (20 mg/kg body weight/day) via oral gavage, beginning 3 days prior to injury. Gelatinase activity and neointima formation were analyzed 3 days and 14 days after balloon injury, respectively. 14 days after vascular injury, proliferative activity was assessed by staining for Ki67.</p> <p>Results</p> <p>After 14 days, animals in the rosuvastatin group showed a decrease in total neointima formation (0.194 ± 0.01 mm²versus 0.124 ± 0.02 mm², p < 0.05) as well as a reduced intima/media ratio (1.26 ± 0.1 versus 0.75 ± 0.09, p < 0.05). Balloon injury resulted in increased activity of MMP-9 3 days after intervention for both rosuvastatin treated animals and controls with no significant difference observed between the groups. There was a trend towards a reduction in the number of Ki67-positive cells 14 days after injury.</p> <p>Conclusions</p> <p>Rosuvastatin attenuates neointima formation without affecting early MMP-9 activity in a rat model of vascular injury.</p

Future of fundamental discovery in US biomedical research

Young researchers are crucially important for basic science as they make unexpected, fundamental discoveries. Since 1982, we find a steady drop in the number of grant-eligible basic-science faculty [principal investigators (PIs)] younger than 46. This fall occurred over a 32-y period when inflation-corrected congressional funds for NIH almost tripled. During this time, the PI success ratio (fraction of basicscience PIs who are R01 grantees) dropped for younger PIs (below 46) and increased for older PIs (above 55). This age-related bias seems to have caused the steady drop in the number of young basicscience PIs and could reduce future US discoveries in fundamental biomedical science. The NIH recognized this bias in its 2008 earlystage investigator (ESI) policy to fund young PIs at higher rates. We show this policy is working and recommend that it be enhanced by using better data. Together with the National Institute of General Medical Sciences (NIGMS)Maximizing Investigators' Research Award (MIRA) program to reward senior PIs with research time in exchange for less funding, this may reverse a decades-long trend of more money going to older PIs. To prepare young scientists for increased demand, additional resources should be devoted to transitional postdoctoral fellowships already offered by NIH.A

Dabigatran etexilate retards the initiation and progression of atherosclerotic lesions and inhibits the expression of oncostatin M in apolipoprotein E-deficient mice

Michael R Preusch,1,2 Nicholas Ieronimakis,1 Errol S Wijelath,3 Sara Cabbage,1 Jerry Ricks,1 Florian Bea,2 Morayma Reyes,1 Joanne van Ryn,4 Michael E Rosenfeld1,5 1Department of Pathology, University of Washington, Seattle, WA, USA; 2Department of Internal Medicine, University of Heidelberg, Heidelberg, Germany; 3Department of Surgery, University of Washington, Seattle, WA, USA; 4Department of CardioMetabolic Disease Research, Boehringer Ingelheim Pharma GmbH &amp; Co KG, Biberach, Germany; 5Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA Objective: Thrombin has multiple proatherogenic effects including platelet activation and the induction of inflammatory processes. Recently, the cytokine oncostatin M has been shown to have proinflammatory effects. This study was designed to investigate the effects of thrombin inhibition on the initiation and progression of atherosclerosis and on the expression of oncostatin M. Methods: Apolipoprotein E-deficient mice at different ages were fed the thrombin inhibitor dabigatran etexilate. The mean lesion area was measured in the aortic sinus and in the innominate artery. CD45-positive cells within the aortic tissue were measured by flow cytometry. Oncostatin M expression was measured in the tissue sections by immunocytochemistry. Results: Treatment with dabigatran etexilate resulted in a significant reduction of the mean area of atherosclerotic lesions in the aortic sinus in both the young mice (11,176&plusmn;1,500 &micro;m2 (control) versus 3,822&plusmn;836 &micro;m2 (dabigatran etexilate), P&lt;0.05) and selectively in the older mice at 28 weeks (234,099&plusmn;13,500 &micro;m2 (control) versus 175,226&plusmn;16,132 &micro;m2 (dabigatran etexilate), P&lt;0.05). There were also fewer CD45-positive cells within the aortas of the dabigatran-treated mice and enhanced NO production in endothelial cells pretreated with dabigatran. In addition, the expression of oncostatin M was reduced in the lesions of dabigatran etexilate-treated mice. Conclusion: Inhibition of thrombin by dabigatran retards the development of early lesions and the progression of some established lesions in ApoE-/- mice. It improves endothelial function and retards macrophage accumulation within the vascular wall. Dabigatran also inhibits the expression of oncostatin M, and this suggests that oncostatin M may play a role in the initiation and progression of atherosclerosis. Keywords: macrophages, thrombin, coagulation, inflammatio