The astrocyte scar – not so inhibitory after all?

Damaged adult central nervous system axons have very limited regenerative capacity,if any.Other than an intrinsic deficiency（Liu et al.,2011）in axonal extension and guidance compared to embryonic neurons or peripheral neurons,the injury site is also generally viewed to be non-permissive for axonal regrowth.In particular,

CYP2C8-derived Epoxyeicosatrienoic Acids Decrease Oxidative Stress-induced Endothelial Apoptosis in Development of Atherosclerosis:Role of Nrf2 Activation

The aim of the present study is to investigate how cytochrome P450 enzymes（CYP） 2C8-derived epoxyeicosatrienoic acids（EETs） regulate the nuclear factor erythroid 2-related factor 2（Nrf2） signaling pathway and protect against oxidative stress-induced endothelial injuries in the development and progression of atherosclerosis. In this study,cultured human umbilical vein endothelial cells（HUVECs） were transfected with CYP2C8 or pretreated with exogenous EETs（1 μmol/L） before TNF-α（20 ng/m L） stimulation. Apoptosis and intracellular ROS production were determined by flow cytometry. The expression levels of ROS-associated NAD（P）H subunits gp91 and p47,the anti-oxidative enzyme catalase（CAT）,Nrf2,heme oxygenase-1（HO-1） and endothelial nitric oxide synthase（e NOS） were detected by Western blotting. The results showed that CYP2C8-derived EETs decreased apoptosis of HUVECs treated with TNF-α. Pretreatment with 11,12-EET also significantly blocked TNF-α-induced ROS production. In addition,11,12-EET decreased oxidative stress-induced apoptosis. Furthermore,the ability of 11,12-EET to protect cells against TNF-α-induced apoptosis via oxidative stress was abrogated by transient transfection with Nrf2-specific small interfering RNA（si RNA）. In conclusion,CYP2C8-derived EETs prevented TNF-α-induced HUVECs apoptosis via inhibition of oxidative stress associated with the Nrf2 signaling.

Recent progress of sugar amino acids: Synthetic strategies and applications as glycomimetics and peptidomimetics

In order to meet the increasing demands for the development of large varieties of new molecules for discovering new drugs and materials, organic chemists are developing many novel multifunctional building blocks, which are assembled rationally to create ‘nature-like＇ and yet unnatural organic molecules with well-defined structures and useful properties. Sugar amino acids（SAAs）, the carbohydrate derivatives bearing both amino and carboxylic acid functional groups, are important ones of these multifunctional building blocks, which can be used to create novel materials with potential applications as glycomimetics and peptidomimetics. This review will focus on recent synthetic strategies of SAAs and their applications in creating large number of structurally diverse glycomimetics and peptidomimetics.