Chlorogenic acid/chromium supplement rescues diet-induced insulin resistance and obesity in mice.

Abdominal obesity is a major risk factor for insulin resistance, type 2 diabetes and cardiovascular diseases. Dietary fat induces insulin resistance in humans and rodents. The current study investigates whether a Chlorogenic acid/Chromium III supplement rescues obesity and insulin resistance caused by high-fat feeding of male C57BL/6 J mice for 7 weeks. Administering an oral daily dose of this supplement in the last 3 weeks of feeding reversed diet-induced body weight gain and insulin resistance, assessed by hyperglycemia, glucose intolerance and insulin intolerance. Indirect calorimetry analysis revealed that this effect is mediated at least partly, by increasing energy expenditure and spontaneous locomoter activity. These findings underscore the important role that chlorogenic acid and chromium play in maintaining glucose metabolism and insulin response in mice fed a high-fat diet.

Assessment of coronary stent by optical coherence tomography, methodology and definitions.

Optical coherence tomography has emerged as a powerful tool for stent assessment, and in a short time, has become the modality of choice for studying stent and vascular interactions in vivo. In this review, we discuss qualitative and quantitative parameters used for stent assessment by OCT. Various qualitative/quantitative variables of stent assessment are discussed in the perspective of the clinical and research values of each of them.

Specificity determinants of a novel Nck interaction with the juxtamembrane domain of the epidermal growth factor receptor.

Nck is a ubiquitously expressed adaptor protein containing Src homology 2 (SH2) and Src homology 3 (SH3) domains. It integrates downstream effector proteins with cell membrane receptors, such as the epidermal growth factor receptor (EGFR). EGFR plays a critical role in cellular proliferation and differentiation. The 45-residue juxtamembrane domain of EGFR (JM), located between the transmembrane and kinase domains, regulates receptor activation and trafficking to the basolateral membrane of polarized epithelia through a proline-rich motif that resembles a consensus SH3 domain binding site. We demonstrate here that the JM region can bind to Nck, showing a notable binding preference for the second SH3 domain. To elucidate the structural determinants for this interaction, we have determined the NMR solution structures of both the first and second Nck SH3 domains (Nck1-1 and Nck1-2). These domains adopt a canonical SH3 beta-barrel-like fold, containing five antiparallel strands separated by three loop regions and one 3 10-helical turn. Chemical shift perturbation studies have identified the residues that form the binding cleft of Nck1-2, which are primarily located in the RT and n-Src loops. JM binds to Nck1-2 with an affinity of approximately 80 microM through a positively charged sequence near the N-terminus, as opposed to the polyproline sequence. The two Nck SH3 domains exhibit both steric and electrostatic differences in their RT-Src and n-Src loops, and a model of the Nck1-2 domain complexed with the JM highlights the factors that define the putative binding mode for this ligand.