Description: Plumbagin (PL), 5-hydroxy-2-methyl-1,4-naphthoquinone, is a quinoid constituent isolated from the roots of the medicinal plant Plumbago zeylanica L. (also known as chitrak). PL has also been found in Juglans regia (English Walnut), Juglans cinerea (whitenut) and Juglans nigra (blacknut). The roots of P. zeylanica have been used in Indian and Chinese systems of medicine for more than 2500 years for the treatment of various types of ailments. We were the first to report that PL inhibits the growth and invasion of hormone refractory prostate cancer (PCa) cells [Aziz,M.H. et al . (2008) Plumbagin, a medicinal plant-derived naphthoquinone, is a novel inhibitor of the growth and invasion of hormone-refractory prostate cancer. Cancer Res., 68, 9024–9032.]. Now, we present that PL inhibits in vivo PCa development in the transgenic adenocarcinoma of mouse prostate (TRAMP). PL treatment (2mg/kg body weight i.p. in 0.2ml phosphate-buffered saline, 5 days a week) to FVB–TRAMP resulted in a significant ( P 〈 0.01) decrease in prostate tumor size and urogenital apparatus weights at 13 and 20 weeks. Histopathological analysis revealed that PL treatment inhibited progression of prostatic intraepithelial neoplasia (PIN) to poorly differentiated carcinoma (PDC). No animal exhibited diffuse tumor formation in PL-treated group at 13 weeks, whereas 75% of the vehicle-treated mice elicited diffuse PIN and large PDC at this stage. At 20 weeks, 25% of the PL-treated animals demonstrated diffuse PIN and 75% developed small PDC, whereas 100% of the vehicle-treated mice showed large PDC. PL treatment inhibited expression of protein kinase C epsilon (PKC), signal transducers and activators of transcription 3 phosphorylation, proliferating cell nuclear antigen and neuroendocrine markers (synaptophysin and chromogranin-A) in excised prostate tumor tissues. Taken together, these results further suggest PL could be a novel chemopreventive agent against PCa.

Description: Assisted reproductive technologies (ART) are associated with several complications including low birth weight, abnormal placentation and increased risk for rare imprinting disorders. Indeed, experimental studies demonstrate ART procedures independent of existing infertility induce epigenetic perturbations in the embryo and extraembryonic tissues. To test the hypothesis that these epigenetic perturbations persist and result in adverse outcomes at term, we assessed placental morphology and methylation profiles in E18.5 mouse concepti generated by in vitro fertilization (IVF) in two different genetic backgrounds. We also examined embryo transfer (ET) and superovulation procedures to ascertain if they contribute to developmental and epigenetic effects. Increased placental weight and reduced fetal-to-placental weight ratio were observed in all ART groups when compared with naturally conceived controls, demonstrating that non-surgical embryo transfer alone can impact placental development. Furthermore, superovulation further induced overgrowth of the placental junctional zone. Embryo transfer and superovulation defects were limited to these morphological changes, as we did not observe any differences in epigenetic profiles. IVF placentae, however, displayed hypomethylation of imprinting control regions of select imprinted genes and a global reduction in DNA methylation levels. Although we did not detect significant differences in DNA methylation in fetal brain or liver samples, rare IVF concepti displayed very low methylation and abnormal gene expression from the normally repressed allele. Our findings suggest that individual ART procedures cumulatively increase placental morphological abnormalities and epigenetic perturbations, potentially causing adverse neonatal and long-term health outcomes in offspring.

Description: The reconstruction of the history of rearrangements and the reconstruction of ancestral genomes are some of the challenges of bioinformatics today. Many algorithms already exist, treating one or the other question but none treating both. These reconstructions are interdependent and we argue on the interest of treating both problems in parallel to lead to a richer and more complete output. We also argue on the importance of redefining several steps of these algorithms to improve both reconstructions: the identification of synteny blocks has to be as precise as possible, and the treatment of multiple genomes has to be based on pairwise comparisons to ensure the most detailed reconstructions. In this article, we highlight novel solutions to these points and focus on the need of explicitly treating overlapping, included, duplicated and unsigned synteny blocks. To do so, we introduce the new notion of synteny pack , which is a representation of local hypothetical intermediate ancestral genomes. We discuss a number of examples on yeast genomes to illustrate the importance of such a definition.

Description: The surveillance of acid-base homeostasis is concerted by diverse mechanisms, including an activation of sensory afferents. Proton-evoked activation of rodent sensory neurons is mainly mediated by the capsaicin receptor TRPV1 and acid-sensing ion channels. In this study, we demonstrate that extracellular acidosis activates and sensitizes the human irritant receptor TRPA1 (hTRPA1). Proton-evoked membrane currents and calcium influx through hTRPA1 occurred at physiological acidic pH values, were concentration-dependent, and were blocked by the selective TRPA1 antagonist HC030031. Both rodent and rhesus monkey TRPA1 failed to respond to extracellular acidosis, and protons even inhibited rodent TRPA1. Accordingly, mouse dorsal root ganglion neurons lacking TRPV1 only responded to protons when hTRPA1 was expressed heterologously. This species-specific activation of hTRPA1 by protons was reversed in both mouse and rhesus monkey TRPA1 by exchange of distinct residues within transmembrane domains 5 and 6. Furthermore, protons seem to interact with an extracellular interaction site to gate TRPA1 and not via a modification of intracellular N-terminal cysteines known as important interaction sites for electrophilic TRPA1 agonists. Our data suggest that hTRPA1 acts as a sensor for extracellular acidosis in human sensory neurons and should thus be taken into account as a yet unrecognized transduction molecule for proton-evoked pain and inflammation. The species specificity of this property is unique among known endogenous TRPA1 agonists, possibly indicating that evolutionary pressure enforced TRPA1 to inherit the role as an acid sensor in human sensory neurons.

Description: It has been proposed recently that ATP hydrolysis in ATPase enzymes proceeds via an initial intermediate in which the dissociated γ-phosphate of ATP is bound in the protein as a metaphosphate (PγO3−). A combined quantum/classical analysis of this dissociated nucleotide state inside myosin provides a quantitative understanding of how the enzyme stabilizes this unusual metaphosphate. Indeed, in vacuum, the energy of the ADP3−·PγO3−·Mg2+ complex is much higher than that of the undissociated ATP4−. The protein brings it to a surprisingly low value. Energy decomposition reveals how much each interaction in the protein stabilizes the metaphosphate state; backbone peptides of the P-loop contribute 50% of the stabilization energy, and the side chain of Lys-185+ contributes 25%. This can be explained by the fact that these groups make strong favorable interactions with the α- and β-phosphates, thus favoring the charge distribution of the metaphosphate state over that of the ATP state. Further stabilization (16%) is achieved by a hydrogen bond between the backbone C=O of Ser-237 (on loop Switch-1) and a water molecule perfectly positioned to attack the PγO3− in the subsequent hydrolysis step. The planar and singly negative PγO3− is a much better target for the subsequent nucleophilic attack by a negatively charged OH− than the tetrahedral and doubly negative PγO42− group of ATP. Therefore, we argue that the present mechanism of metaphosphate stabilization is common to the large family of nucleotide-hydrolyzing enzymes. Methodologically, this work presents a computational approach that allows us to obtain a truly quantitative conception of enzymatic strategy.

Description: Cell-cell contact inhibition and the mechanical environment of cells have both been shown to regulate YAP nuclear localization to modulate cell proliferation. Changes in cellular contractility by genetic, pharmacological, and matrix stiffness perturbations regulate YAP nuclear localization. However, because contractility and F-actin organization are interconnected cytoskeletal properties, it remains unclear which of these distinctly regulates YAP localization. Here we show that in the absence of cell-cell contact, actomyosin contractility suppresses YAP phosphorylation at Ser112, however, neither loss of contractility nor increase in YAP phosphorylation is sufficient for its nuclear exclusion. We find that actin cytoskeletal integrity is essential for YAP nuclear localization, and can override phosphoregulation or contractility-mediated regulation of YAP nuclear localization. This actin-mediated regulation is conserved during mechanotransduction, as substrate compliance increased YAP phosphorylation and reduced cytoskeletal integrity leading to nuclear exclusion of both YAP and Ser(P)112-YAP. These data provide evidence for two actin-mediated pathways for YAP regulation; one in which actomyosin contractility regulates YAP phosphorylation, and a second that involves cytoskeletal integrity-mediated regulation of YAP nuclear localization independent of contractility. We suggest that in non-contact inhibited cells, this latter mechanism may be important in low stiffness regimes, such as may be encountered in physiological environments.

Description: The genetic contribution to the variation in human lifespan is ~25%. Despite the large number of identified disease-susceptibility loci, it is not known which loci influence population mortality. We performed a genome-wide association meta-analysis of 7729 long-lived individuals of European descent (≥85 years) and 16 121 younger controls (〈65 years) followed by replication in an additional set of 13 060 long-lived individuals and 61 156 controls. In addition, we performed a subset analysis in cases aged ≥90 years. We observed genome-wide significant association with longevity, as reflected by survival to ages beyond 90 years, at a novel locus, rs2149954, on chromosome 5q33.3 (OR = 1.10, P = 1.74 x 10 –8 ). We also confirmed association of rs4420638 on chromosome 19q13.32 (OR = 0.72, P = 3.40 x 10 –36 ), representing the TOMM40 / APOE / APOC1 locus. In a prospective meta-analysis ( n = 34 103), the minor allele of rs2149954 (T) on chromosome 5q33.3 associates with increased survival (HR = 0.95, P = 0.003). This allele has previously been reported to associate with low blood pressure in middle age. Interestingly, the minor allele (T) associates with decreased cardiovascular mortality risk, independent of blood pressure. We report on the first GWAS-identified longevity locus on chromosome 5q33.3 influencing survival in the general European population. The minor allele of this locus associates with low blood pressure in middle age, although the contribution of this allele to survival may be less dependent on blood pressure. Hence, the pleiotropic mechanisms by which this intragenic variation contributes to lifespan regulation have to be elucidated.

Description: Plectin, a versatile 500-kDa cytolinker protein, is essential for muscle fiber integrity and function. The most common disease caused by mutations in the human plectin gene, epidermolysis bullosa simplex with muscular dystrophy (EBS-MD), is characterized by severe skin blistering and progressive muscular dystrophy. Besides displaying pathological desmin-positive protein aggregates and degenerative changes in the myofibrillar apparatus, skeletal muscle specimens of EBS-MD patients and plectin-deficient mice are characterized by massive mitochondrial alterations. In this study, we demonstrate that structural and functional alterations of mitochondria are a primary aftermath of plectin deficiency in muscle, contributing to myofiber degeneration. We found that in skeletal muscle of conditional plectin knockout mice (MCK-Cre/cKO), mitochondrial content was reduced, and mitochondria were aggregated in sarcoplasmic and subsarcolemmal regions and were no longer associated with Z-disks. Additionally, decreased mitochondrial citrate synthase activity, respiratory function and altered adenosine diphosphate kinetics were characteristic of plectin-deficient muscles. To analyze a mechanistic link between plectin deficiency and mitochondrial alterations, we comparatively assessed mitochondrial morphology and function in whole muscle and teased muscle fibers of wild-type, MCK-Cre/cKO and plectin isoform-specific knockout mice that were lacking just one isoform (either P1b or P1d) while expressing all others. Monitoring morphological alterations of mitochondria, an isoform P1b-specific phenotype affecting the mitochondrial fusion–fission machinery and manifesting with upregulated mitochondrial fusion-associated protein mitofusin-2 could be identified. Our results show that the depletion of distinct plectin isoforms affects mitochondrial network organization and function in different ways.

Description: Thin porous films of [Cu3(btc)2]n metal organic framework were deposited in a stepwise manner on surfaces of flexible organic polymers. The thickness of deposited film can be precisely controlled. The deposition of the first cycles was monitored by UV-vis spectroscopy. Mikhail Meilikhov, Kirill Yusenko, Eckhardt Schollmeyer, Christian Mayer, Hans-Jurgen Buschmann, Roland A. Fischer ( from Dalton Trans.) Mikhail Meilikhov, Dalton Trans., 2011, DOI: 10.1039/C0DT01820A To cite this article before page numbers are assigned, use the DOI form of citation above. The content of this RSS Feed (c) The Royal Society of Chemistry

Description: Strongly oriented Co3O4 thin films were grown on MgO(100) and MgAl2O4(100) by plasma CVD. XPS, SIMS, FE-SEM and XRD2 analyses evidenced that a tailored structural/morphological evolution could be obtained as a function of the process parameters. Davide Barreca, Anjana Devi, Roland A. Fischer, Daniela Bekermann, Alberto Gasparotto, Marco Gavagnin, Chiara Maccato, Eugenio Tondello, Elza Bontempi, Laura E. Depero, Cinzia Sada ( from CrystEngComm) Davide Barreca, CrystEngComm, 2011, DOI: 10.1039/C1CE05280B To cite this article before page numbers are assigned, use the DOI form of citation above. The content of this RSS Feed (c) The Royal Society of Chemistry