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AMP-activated protein kinase (AMPK), a known regulator of cellular and systemic energy balance, is now recognized to control cell division, cell polarity and cell migration, all of which depend on the actin cytoskeleton. Here we report the effects of A769662, a pharmacological activator of AMPK, on cytoskeletal organization and signalling in epithelial Madin-Darby canine kidney (MDCK) cells. We show that AMPK activation induced shortening or radiation of stress fibers, uncoupling from paxillin and predominance of cortical F-actin. In parallel, Rho-kinase downstream targets, namely myosin regulatory light chain and cofilin, were phosphorylated. These effects resembled the morphological changes in MDCK cells exposed to hyperosmotic shock, which led to Ca(2+)-dependent AMPK activation via calmodulin-dependent protein kinase kinase-beta(CaMKKbeta), a known upstream kinase of AMPK. Indeed, hypertonicity-induced AMPK activation was markedly reduced by the STO-609 CaMKKbeta inhibitor, as was the increase in MLC and cofilin phosphorylation. We suggest that AMPK links osmotic stress to the reorganization of the actin cytoskeleton.

ObjectivesWe compared the prevalence and extent of coronary artery calcium (CAC) among persons with the metabolic syndrome (MetS), diabetes, and neither condition.BackgroundThe prevalence and extent of CAC has not been compared among those with MetS, diabetes, or neither condition.MethodsOf 1,823 persons (36% female) age 20 to 79 years who had screening for CAC by computed tomography, 279 had MetS, 150 had diabetes, and the remainder (n = 1,394) had neither condition. Metabolic syndrome was defined with ≥3 of the following: body mass index ≥30 kg/m2; high-density lipoprotein cholesterol 20% 10-year risk of CHD or CAC ≥75th percentile for age and gender. Risk factor-adjusted odds for the presence of CAC were 1.40 (95% confidence interval [CI] 1.05 to 1.87) among those with MetS and 1.67 (95% CI 1.12 to 2.50) among those with diabetes, versus those with neither condition.ConclusionsThose with MetS or diabetes have an increased likelihood of CAC compared with those having neither condition.

The composition of potatoes as determined by chemical extraction has been described extensively. It is thus quite well known that, among other compounds, potato is rich in polyphenols, vitamins and in some minerals. This paper underlines the important role of simulated gastro-intestinal in vitro digestion in the bioaccessibility of polyphenols (chlorogenic acid and derivatives, and rutin) from potatoes and sweet potatoes and their impact on iron uptake. Concentrations of polyphenols in the flesh of two potato cultivars (Nicola, white potato, and Vitelotte, purple potato) and sweet potato were measured by Ultra Performance Liquid Chromatography after boiling and after in vitro digestion. Chemical extraction underestimates polyphenol amounts that can be released during digestion and that are actually bioaccessible. Iron uptake, as evaluated by a ferritin assay, by intestinal human cells was decreased after incubation with the intestinal phase of in vitro digestion, presumably due to the presence of polyphenols.

Pentacyclic triterpenes are naturally found in a great variety of fruits, vegetables and medicinal plants and are therefore part of the human diet. The beneficial health effects of edible and medicinal plants have partly been associated with their triterpene content, but the in vivo efficacy in humans depends on many factors, including absorption and metabolism. This review presents an overview of in vitro and in vivo studies that were carried out to determine the bioavailability of pentacyclic triterpenes and highlights the efforts that have been performed to improve the dissolution properties and absorption of these compounds. As plant matrices play a critical role in triterpene bioaccessibility, this review covers literature data on the bioavailability of pentacyclic triterpenes ingested either from foods and medicinal plants or in their free form.