A hypocaloric diet enriched in legumes specifically mitigates lipid peroxidation in obese subjects

Legume intake could specifically protect against lipid peroxidation in addition to the effects associated to weight loss when included in hypocaloric diets. Thus, 30 obese subjects (age: 36 +/- 8 years and BMI: 32.0 +/- 5.3 kg/m(2)) were nutritionally treated by a 8-week energy restriction ( - 30% energy expenditure) with a legume enriched diet (4 days/week servings, [image omitted] ) or without legumes (control diet (CD), [image omitted] ). Body weight, circulating cholesterol, oxidized LDL (ox-LDL), malondialdehyde (MDA) and urinary 8-isoprostane F(2alpha) (8-iso-PGF(2alpha)) were measured at baseline and at endpoint. After the nutritional intervention, all obese subjects lost weight, specially those individuals who followed the legumes-enriched diet as compared to the CD ( - 7.7 +/- 3 vs. - 5.3 +/- 2.7%; p = 0.023), which was accompanied by marked decreases in total cholesterol levels (p < 0.001) and statistically significant diet-related reductions on plasma ox-LDL, plasma MDA and urinary 8-iso-PGF(2alpha) output. Therefore, a balanced diet with moderate caloric restriction including 4 day/week legume servings empowered the oxidative stress improvement related to weight loss through a reduction in lipid peroxidation as compared to a control hypocaloric diet.     

ZO-1 is required for protein kinase C gamma-driven disassembly of connexin 43

We have previously reported that protein kinase C gamma (PKC-gamma) is activated by phorbol-12-myristate-13-acetate (TPA) and that this causes PKC-gamma translocation to membranes and phosphorylation of the gap junction protein, connexin 43 (Cx43). This phosphorylation, on S368 of Cx43, causes disassembly of Cx43 out of cell junctional plaques resulting in the inhibition of dye transfer. The purpose of this study is to identify the specific role of zonula occludens protein-1 (ZO-1), a tight junction protein with recently established effects on gap junctions, in this PKC-gamma-driven Cx43 disassembly. For this purpose, ZO-1 levels in lens epithelial cells in culture were decreased by up to 70% using specific siRNA. The down-regulation of ZO-1 caused a stable interaction of PKC-gamma with Cx43 even without normal enzyme activation by TPA. However, after TPA activation of the PKC-gamma, the Cx43 did not disassemble out of plaques even though the PKC-gamma enzyme was activated and the Cx43 was phosphorylated on S368. Confocal microscopy demonstrated that the siRNA treatment caused a loss of ZO-1 from borders of large junctional Cx43 cell-to-cell plaques and resulted in the accumulation of Cx43 aggregates inside of cells. Loss of the specific "plaquetosome" arrangement of large Cx43 plaques surrounded by ZO-1 was accompanied by a complete loss of functional dye transfer. These results suggest that ZO-1 is required for Cx43 control, both for dye transfer, and, for the PKC-gamma-driven disassembly response.     

Regulation of the Glycine Transporter GLYT1 by microRNAs

Neurochemical Research - The glycine transporter GLYT1 participates in inhibitory and excitatory neurotransmission by controlling the reuptake of this neuroactive substance from synapses. Over the...     

Vibrio cholerae MARTX toxin heterologous translocation of beta‐lactamase and roles of individual effector domains on cytoskeleton dynamics

The Vibrio cholerae MARTX_Vc toxin delivers three effector domains to eukaryotic cells. To study toxin delivery and function of individual domains, the rtxA gene was modified to encode toxin with an in‐frame beta‐lactamase (Bla) fusion. The hybrid RtxA::Bla toxin was Type I secreted from bacteria; and then Bla was translocated into eukaryotic cells and delivered by autoprocessing, demonstrating that the MARTX_Vc toxin is capable of heterologous protein transfer. Strains that produce hybrid RtxA::Bla toxins that carry one effector domain in addition to Bla were found to more efficiently translocate Bla. In cell biological assays, the actin cross‐linking domain (ACD) and Rho‐inactivation domain (RID) are found to cross‐link actin and inactivate RhoA, respectively, when other effector domains are absent, with toxin autoprocessing required for high efficiency. The previously unstudied alpha‐beta hydrolase domain (ABH) is shown here to activate CDC42, although the effect is ameliorated when RID is also present. Despite all effector domains acting on cytoskeleton assembly, the ACD was sufficient to rapidly inhibit macrophage phagocytosis. Both the ACD and RID independently disrupted polarized epithelial tight junction integrity. The sufficiency of ACD but strong selection for retention of RID and ABH suggests these two domains may primarily function by modulating cell signaling.     

Identification and characterization of an ABA‐activated MAP kinase cascade in Arabidopsis thaliana

Abscisic acid (ABA) is a major phytohormone involved in important stress‐related and developmental plant processes. Recent phosphoproteomic analyses revealed a large set of ABA‐triggered phosphoproteins as putative mitogen‐activated protein kinase (MAPK) targets, although the evidence for MAPKs involved in ABA signalling is still scarce. Here, we identified and reconstituted in vivo a complete ABA‐activated MAPK cascade, composed of the MAP3Ks MAP3K17/18, the MAP2K MKK3 and the four C group MAPKs MPK1/2/7/14. In planta, we show that ABA activation of MPK7 is blocked in mkk3‐1 and map3k17mapk3k18 plants. Coherently, both mutants exhibit hypersensitivity to ABA and altered expression of a set of ABA‐dependent genes. A genetic analysis further reveals that this MAPK cascade is activated by the PYR/PYL/RCAR‐SnRK2‐PP2C ABA core signalling module through protein synthesis of the MAP3Ks, unveiling an atypical mechanism for MAPK activation in eukaryotes. Our work provides evidence for a role of an ABA‐induced MAPK pathway in plant stress signalling.     

Male secondary sexual structures and the systematics of the Thereus oppia species group (Lepidoptera,Lycaenidae, Eumaeini)

The Thereus oppia species group includes species with and without a scent pad, which is a histologically and morphologically characterized male secondary sexual structure on the dorsal surface of the forewing. To assess the hypothesis that these structures are lost evolutionarily, but not regained (Dollo’s Law), the taxonomy of this species group is revised. Thereus lomalarga sp. n., and Thereus brocki sp. n., are described. Diagnostic traits, especially male secondary structures, within the Thereus oppia species group are illustrated. Distributional and biological information is summarized for each species. Three species have been reared, and the caterpillars eat Loranthaceae. An inferred phylogeny is consistent with the hypothesis that scent pads in the Thereus oppia species group have been lost evolutionarily twice (in allopatry), and not re-gained.