Transcriptome‐based target‐enrichment baits for stony corals (Cnidaria: Anthozoa: Scleractinia)

Despite the ecological and economic significance of stony corals (Scleractinia), a robust understanding of their phylogeny remains elusive due to patchy taxonomic and genetic sampling, as well as the limited availability of informative markers. To increase the number of genetic loci available for phylogenomic analyses in Scleractinia, we designed 15,919 DNA enrichment baits targeting 605 orthogroups (mean 565 ± SD 366 bp) over 1,139 exon regions. A further 236 and 62 barcoding baits were designed for COI and histone H3 genes respectively for quality and contamination checks. Hybrid capture using these baits was performed on 18 coral species spanning the presently understood scleractinian phylogeny, with two corallimorpharians as outgroup. On average, 74% of all loci targeted were successfully captured for each species. Barcoding baits were matched unambiguously to their respective samples and revealed low levels of cross‐contamination in accordance with expectation. We put the data through a series of stringent filtering steps to ensure only scleractinian and phylogenetically informative loci were retained, and the final probe set comprised 13,479 baits, targeting 452 loci (mean 531 ± SD 307 bp) across 865 exon regions. Maximum likelihood, Bayesian and species tree analyses recovered maximally supported, topologically congruent trees consistent with previous phylogenomic reconstructions. The phylogenomic method presented here allows for consistent capture of orthologous loci among divergent coral taxa, facilitating the pooling of data from different studies and increasing the phylogenetic sampling of scleractinians in the future.     

FAT/CD36 is located on the outer mitochondrial membrane, upstream of long-chain acyl-CoA synthetase, and regulates palmitate oxidation

FAT/CD36 (fatty acid translocase/Cluster of Differentiation 36), a plasma membrane fatty-acid transport protein, has been found on mitochondrial membranes; however, it remains unclear where FAT/CD36 resides on this organelle or its functional role within mitochondria. In the present study, we demonstrate, using several different approaches, that in skeletal muscle FAT/CD36 resides on the OMM (outer mitochondrial membrane). To determine the functional role of mitochondrial FAT/CD36 in this tissue, we determined oxygen consumption rates in permeabilized muscle fibres in WT (wild-type) and FAT/CD36-KO (knockout) mice using a variety of substrates. Despite comparable muscle mitochondrial content, as assessed by unaltered mtDNA (mitochondrial DNA), citrate synthase, β-hydroxyacyl-CoA dehydrogenase, cytochrome c oxidase complex IV and respiratory capacities [maximal OXPHOS (oxidative phosphorylation) respiration] in WT and KO mice, palmitate-supported respiration was 34% lower in KO animals. In contrast, palmitoyl-CoA-supported respiration was unchanged. These results indicate that FAT/CD36 is key for palmitate-supported respiration. Therefore we propose a working model of mitochondrial fatty-acid transport, in which FAT/CD36 is positioned on the OMM, upstream of long-chain acyl-CoA synthetase, thereby contributing to the regulation of mitochondrial fatty-acid transport. We further support this model by providing evidence that FAT/CD36 is not located in mitochondrial contact sites, and therefore does not directly interact with carnitine palmitoyltransferase-I as original proposed.     

Polymer based biosensor for rapid electrochemical detection of virus infection of human cells

The demand in the field of medical diagnostics for simple, cost efficient and disposable devices is growing. Here, we present a label free, all-polymer electrochemical biosensor for detection of acute viral disease. The dynamics of a viral infection in human cell culture was investigated in a micro fluidic system on conductive polymer PEDOT:TsO microelectrodes by electrochemical impedance spectroscopy and video time lapse microscopy. Employing this sensitive, real time electrochemical technique, we could measure the immediate cell response to cytomegalovirus, and detect an infection within 3h, which is several hours before the cytopathic effect is apparent with conventional imaging techniques. Atomic force microscopy and scanning ion conductance microscopy imaging consolidate the electrochemical measurements by demonstrating early virus induced changes in cell morphology of apparent programmed cell death.     

Assessment of in vivo and in vitro cytotoxic activity of hydrolysable tannin extracted from Rhizophora apiculata barks

World Journal of Microbiology and Biotechnology - Rhizophora apiculata is a common mangrove tree in Malaysia. The bark of this tree has been reported to contain a chemical constituent such as...     

Oxidative stress, insulin signaling, and diabetes

Oxidative stress has been implicated as a contributor to both the onset and the progression of diabetes and its associated complications. Some of the consequences of an oxidative environment are the development of insulin resistance, β-cell dysfunction, impaired glucose tolerance, and mitochondrial dysfunction, which can lead ultimately to the diabetic disease state. Experimental and clinical data suggest an inverse association between insulin sensitivity and ROS levels. Oxidative stress can arise from a number of different sources, whether disease state or lifestyle, including episodes of ketosis, sleep restriction, and excessive nutrient intake. Oxidative stress activates a series of stress pathways involving a family of serine/threonine kinases, which in turn have a negative effect on insulin signaling. More experimental evidence is needed to pinpoint the mechanisms contributing to insulin resistance in both type 1 diabetics and nondiabetic individuals. Oxidative stress can be reduced by controlling hyperglycemia and calorie intake. Overall, this review outlines various mechanisms that lead to the development of oxidative stress. Intervention and therapy that alter or disrupt these mechanisms may serve to reduce the risk of insulin resistance and the development of diabetes.     

Discovery of inhibitors of plasminogen activator inhibitor-1: structure-activity study of 5-nitro-2-phenoxybenzoic acid derivatives

Two novel series of 5-nitro-2-phenoxybenzoic acid derivatives are designed as potent PAI-1 inhibitors using hybridization and conformational restriction strategy in the tiplaxtinin and piperazine chemo types. The lead compounds 5a, 6c, and 6e exhibited potent PAI-1 inhibitory activity and favorable oral bioavailability in the rodents.     

Complete genome sequence of Corynebacterium pseudotuberculosis strain CIP 52.97, isolated from a horse in Kenya

In this work, we report the whole-genome sequence of Corynebacterium pseudotuberculosis bv. equi strain CIP 52.97 (Collection Institut Pasteur), isolated in 1952 from a case of ulcerative lymphangitis in a Kenyan horse, which has evidently caused significant losses to agribusiness. Therefore, obtaining this genome will allow the detection of important targets for postgenomic studies, with the aim of minimizing problems caused by this microorganism.     

Hydrogen sulfide and L-cysteine increase phosphatidylinositol 3,4,5-trisphosphate (PIP3) and glucose utilization by inhibiting phosphatase and tensin homolog (PTEN) protein and activating phosphoinositide 3-kinase (PI3K)/serine/threonine protein kinase (AKT)/protein kinase Cζ/λ (PKCζ/λ) in 3T3l1 adipocytes

This work examined the novel hypothesis that reduced levels of H(2)S or L-cysteine (LC) play a role in the impaired glucose metabolism seen in diabetes. 3T3L1 adipocytes were treated with high glucose (HG, 25 mM) in the presence or absence of LC or H(2)S. Both LC and H(2)S treatments caused an increase in phosphatidylinositol-3,4,5 trisphosphate (PIP3), AKT phosphorylation, and glucose utilization in HG-treated cells. The effect of LC on PIP3 and glucose utilization was prevented by propargylglycine, an inhibitor of cystathionine γ-lyase that catalyzes H(2)S formation from LC. This demonstrates that H(2)S mediates the effect of LC on increased PIP3 and glucose utilization. H(2)S and LC caused phosphatidylinositol 3-kinase activation and PTEN inhibition. Treatment with LC, H(2)S, or PIP3 increased the phosphorylation of IRS1, AKT, and PKCζ/λ as well as GLUT4 activation and glucose utilization in HG-treated cells. This provides evidence that PIP3 is involved in the increased glucose utilization observed in cells supplemented with LC or H(2)S. Comparative signal silencing studies with siAKT2 or siPKCζ revealed that PKCζ phosphorylation is more effective for the GLUT4 activation and glucose utilization in LC-, H(2)S-, or PIP3-treated cells exposed to HG. This is the first report to demonstrate that H(2)S or LC can increase cellular levels of PIP3, a positive regulator of glucose metabolism. The PIP3 increase is mediated by PI3K activation and inhibition of PTEN but not of SHIP2. This study provides evidence for a molecular mechanism by which H(2)S or LC can up-regulate the insulin-signaling pathways essential for maintenance of glucose metabolism.     

Synthesis and characterization of diethyltin-based three dimensional self-assemblies derived from sulfonate-phosphonate ligands

Diethyltin(methoxy)methanesulfonate reacts readily with equimolar amount of t-butylphosphonic acid (RT, 8-10 h) in moist dichloromethane and methanol to afford [(Et₂Sn)₆(O₃PBu^t)₄(OSO₂Me)₄·CH₂Cl₂]_n (1) and [(Et₂Sn)₆(O₃PBu^t)₄(OSO₂Me)₄·2H₂O]_n (2), respectively. The identity of these compounds has been established by IR, multinuclear (¹H, ¹³C, ³¹P and ¹¹⁹Sn) NMR as well as X-ray crystallographic studies. Despite apparent similarity in the composition, a marked difference in the structural motifs between 1 and 2 is evident in the solid state. For 1, the formation of three-dimensional self- assembly results from μ₃-phosphonate and μ₂, μ₃-sulfonate binding modes and exhibits continuous channel of voids which are occupied by disordered CH₂Cl₂ molecules. In contrast, the sulfonate ligands in 2 act exclusively in μ₂-fashion and hydrogen bonding interactions (O-H?O) between coordinated water molecules and methanesulfonate groups is significant in the construction of 3D supramolecular assembly.