Nanomedicine is the application of nanotechnology in treatment,diagnosis,monitoring and control of biological systems,and is at the leading-edge of clinical medicine and preclinical research.Increasing attention has been paid to the application of nanotechnology in medicine recently(Figure 1).Nanotechnology means the control of matter and processes at a nanoscale(1–100 nm)in one or more dimen-
Heart disease is associated with increased sympathetic nerve activity and elevated levels of circulating catecholamines,resulting in chronic stimulation of the β-adrenergic receptors (β-AR) and consequent pathological cardiac remodeling.Experimentally,chronic administration of the β-AR agonist isoproterenol (ISO) has been most commonly used to model β-AR-induced cardiac remodeling.However,it remains unclear whether β-AR-mediated cardiac remodeling and dysfunction differs between sustained versus pulsatile (intermittent) exposure to a β-agonist.Here,we compare the effects of intermittent versus sustained administration of ISO on cardiac remodeling and function in mice.Animals were administered 5 mg (kg d)-1 ISO for 2 weeks either by daily subcutaneous injection,or continuous infusion via an implanted osmotic minipump.Cardiac function and remodeling were determined by echocardiography,micromanometry and histology.Moreover,Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were utilized to define the proteins and genes involved.Both sustained and intermittent administration of ISO resulted in a similar degree of cardiac hypertrophy (16% and 19%,respectively).However,mice receiving ISO by daily injection developed more severe ventricular systolic and diastolic dysfunction and myocardial fibrosis compared with mice receiving ISO via the osmotic minipump.The disparity in results between the delivery methods is suggested to be due,at least in part,to increased expression of fibrogenic factors,including connective tissue growth factor (CTGF) and NADPH oxidase (NOX4),in mice receiving intermittent application of ISO.In summary,compared with sustained exposure to a β-AR agonist,intermittent β-AR stimulation leads to more severe cardiac dysfunction and fibrosis.These findings not only further our understanding of β-AR function in the setting of cardiac pathophysiology,but also highlight that significant differences can result dependent upon the mode of experimental β-AR stimulation in
MA XiaoWei1,3,SONG Yao1,3,CHEN Chao1,3,FU YongNan1,3,SHEN Qiang2,3,LI ZiJian1,3 & ZHANG YouYi1,3 1Institute of Vascular Medicine,Peking University Third Hospital,Beijing 100191,China
Glycine is a well-documented cytoprotective agent.However,whether it has a protective effect against myocar-dial ischemia-reperfusion injury in vivo is still unknown.By using an open-chest anesthetized rat model,we found that glycine reduced the infarct size by 21% in ischemia-reperfusion injury rats compared with that in the vehicle-treated MI/R rats.The left ventricular ejection fraction and fractional shortening were increased by 19.11% and 30.98%,respectively,in glycine-treated rats.The plasma creatine kinase levels in ischemia-reperfusion injury rats decreased following glycine treatment.Importantly,administration of glycine significantly inhibited apoptosis in post-ischemia-reperfusion myocardium,which was accompanied by suppression of phosphorylated p38 mitogen-activated protein kinase and c-Jun NH2-terminal kinase,as well as the Fas ligand.These results suggest that gly-cine attenuates myocardial ischemia-reperfusion injury in vivo by inhibiting cardiomyocytes apoptosis.
The class A scavenger receptor, encoded by the macrophage scavenger receptor 1 （MSR1） gene, is a pattern recognition receptor （PPR） primarily expressed in macrophages. It has been reported that genetic polymorphisms of MSR1 are significantly associated with the number of diseased vessels and coronary artery narrowing greater than 20% in Caucasians. However, whether it links genetically to coronary artery disease （CAD） in Chinese is not defined. Here, we performed an independent case-control study in a Chinese population consisting of 402 CAD cases and 400 controls by genotyping ten single nucleotide polymorphisms （SNPs） of MSR1. We found that rs416748 and rs13306541 were significantly associated with an increased risk of CAD with per allele odds ratio （OR） of 1.56 [95% confidence interval （CI） = 1.28-1.90; P 〈 0.001] and 1.70 （95% CI = 1.27-2.27; P 〈 0.001）, re- spectively. Our results indicate that genetic variants of MSR1 may serve as predictive markers for the risk of CAD / in combination with traditional risk factors of CAD in Chinese population.
Min ZhangYan ZhangShuaishuai ZhuXiaoyu LiQing YangHui BaiQi Chen
