S-nitrosoglutathione-containing hydrogel increases dermal blood flow in streptozotocin-induced diabetic rats

Background Endothelial dysfunction is characterized by decreased vasodilatory capacity of the arterioles mainly due to the reduced release of nitric oxide (NO). Application of NO donors may prevent or even reverse the consequences of endothelial dysfunction, such as diabetic leg ulcers. ObjectivesTo investigate the vasodilatory capacity and the possible side-effects of topical application of an NO donor-containing hydrogel in diabetic rats. Methods S-nitrosoglutathione (GSNO) was incorporated in Pluronic((R)) F127 hydrogel and applied on the foot sole skin of healthy and streptozotocin-induced diabetic rats. Blood flow was monitored using a laser-Doppler probe. Nitrotyrosine formation, a possible side-effect of GSNO action, was evaluated by Western blotting of skin protein extracts. Systemic circulatory side-effects were investigated by monitoring blood pressure and heart rate during the application. Results The hydrogel alone did not induce any changes in microvascular flow, while GSNO-containing hydrogel caused a twofold increase in perfusion. This effect was similar in diabetic and healthy animals. Topical GSNO application did not increase the nitrotyrosine content of skin proteins, nor did it have any effect on blood pressure or heart rate. Conclusions Dermal application of GSNO may be an effective treatment for promoting the local vasodilation in both healthy and diabetic states, without inducing protein nitration or alterations in blood pressure or heart rate.156581481

Structure and chromosomal DNA binding of the SWIRM domain

The evolutionarily conserved Swi3p, Rsc8p and Moira (SWIRM) domain is found in many chromosomal proteins involved in chromatin modifications or remodeling. Here we report the three-dimensional solution structure of the SWIRM domain from the human transcriptional adaptor ADA2α. The structure reveals a five-helix bundle consisting of two helix-turn-helix motifs connected by a central long helix, reminiscent of the histone fold. Using structural and biochemical analyses, we showed that the SWIRM domains of human ADA2α and SMARC2 bind to double-stranded and nucleosomal DNA, and we identified amino acid residues required for this function. We demonstrated that the ADA2α SWIRM domain is colocalized with lysine-acetylated histone H3 in the cell nucleus and that it potentiates the ACF remodeling activity by enhancing accessibility of nucleosomal linker DNA bound to histone H1. These data suggest a functional role of the SWIRM domain in chromatin remodeling. © 2005 Nature Publishing Group.link_to_subscribed_fulltex