Lysyl oxidase propeptide inhibits smooth muscle cell signaling and proliferation

Lysyl oxidase is required for the normal biosynthesis and maturation of collagen and elastin. It is expressed by vascular smooth muscle cells, and its increased expression has been previously found in atherosclerosis and in models of balloon angioplasty. The lysyl oxidase propeptide (LOX-PP) has more recently been found to have biological activity as a tumor suppressor, and it inhibits Erk1/2 Map kinase activation. We reasoned that LOX-PP may have functions in normal non-transformed cells. We, therefore, investigated its effects on smooth muscle cells, focusing on important biological processes mediated by Erk1/2-dependent signaling pathways including proliferation and matrix metalloproteinase-9 (MMP-9) expression. In addition, we investigated whether evidence for accumulation of LOX-PP could be found in vivo in a femoral artery injury model. Recombinant LOX-PP was expressed and purified, and was found to inhibit primary rat aorta smooth muscle cell proliferation and DNA synthesis by more than 50%. TNF-α-stimulated MMP-9 expression and Erk1/2 activation were both significantly inhibited by LOX-PP. Immunohistochemistry studies carried out with affinity purified anti-LOX-PP antibody showed that LOX-PP epitopes were expressed at elevated levels in vascular lesions of injured arteries. These novel data suggest that LOX-PP may provide a feedback control mechanism that serves to inhibit properties associated with the development of vascular pathology.     

Expression of a synthetic cry1EC gene for resistance against Spodoptera litura in transgenic peanut (Arachis hypogaea L.)

The tobacco cutworm (Spodoptera litura) is a polyphagous foliage insect and a major pest on peanut (Arachis hypogaea L.). S. litura is susceptible to the chimeric delta-endotoxin Cry1EC reported earlier. De-embryonated cotyledon explants of peanut were transformed using Agrobacterium tumefaciens strain EHA101 harboring a synthetic cry1EC gene driven by the CaMV 35S promoter. Transgenic plants of peanut with a single copy insertion of cry1EC were selected in the T(0) generation by Southern blot hybridization. Real-time PCR, Western blot and ELISA analysis indicated that expression of the cry1EC gene was higher in single copy T(1) plants. Immunoassay showed expression of Cry1EC up to 0.13% of total soluble protein in T(1) plants. Leaf feeding bioassay on highly expressing transgenic lines showed 100% killing of larvae at the 2(nd) instar stage of S. litura. This is the first report of transgenic peanut plants with resistance to S. litura.     

Identification of C-terminal neighbours of amino acid residues without an aliphatic <Superscript>13</Superscript>C<Superscript>γ</Superscript> as an aid to NMR assignments in proteins

We propose a methodology that uses GFT (3,2)D CB(CACO)NNH experiment to rapidly collect the data and readily identify six amino acid residue types (Ala, Asn, Asp, Cys, Gly and Ser) in any given protein. Further, the experiment can distinguish the redox state of Cys residues. The proposed experiment in its two forms will have wide range of applications in resonance assignment strategies and structure determination of proteins.     

A sensitive and selective liquid chromatographic tandem mass spectrometric assay for simultaneous quantification of novel trioxane antimalarials in different biomatrices using sample-pooling approach for high throughput pharmacokinetic studies

In the present studies, to give momentum to traditionally low throughput pharmacokinetic screening, a bioanalytical method based on the concept of sample pooling for simultaneous bioanalysis of multiple compounds is discussed. A sensitive, selective, specific and rapid HPLC/ESI-MS/MS assay method was developed and validated for the simultaneous quantitation of three novel trioxane antimalarials (99-357, 99-408 and 99-411) in rat plasma using trioxane analogue as internal standard. The suitably validated bioanalytical method was then further extrapolated to rabbit and monkey plasma by performing partial validation. Extraction from the plasma involves a simple two-step liquid-liquid extraction with n-hexane. The analytes were chromatographed on a cyano column by isocratic elution with acetonitrile:ammonium acetate buffer (pH 6) (85:15, v/v) and analyzed by mass spectrometry in multiple reaction-monitoring (MRM) mode. The chromatographic run time was 5.5 min and the weighted (1/x(2)) calibration curves were linear over a range of 1.56-200 ng/ml. The limit of detection (LOD) and lower limit of quantification (LLOQ) in rat plasma, rabbit plasma and monkey plasma were 0.78 and 1.56 ng/ml, respectively, for all three analytes. The intra- and inter-batch accuracy and precision in terms of % bias and % relative standard deviation were found to be well within the acceptable limits (< 15%). The average absolute recoveries of 99-357, 99-408 and 99-411 from spiked plasma samples were > 90%, > 70% and > 60%, respectively. The assay method described here could be applied to study the pharmacokinetics of 99-357, 99-408 and 99-411 using sample-pooling technique.     

Detection and quantification of ppb level potassium in biological samples in the presence of high sodium by ion chromatographic method

Employing a silica gel column modified with carboxyl groups and an eluent consisting of 4.0mM tartaric acid and 0.75mM dipicolinic acid in 2% acetone, an otherwise difficult quantification of K(+) at ppb level in presence of 6000ppm NaCl was achieved by incorporating 0.75mM 18-crown-6 ether in the mobile phase and subtracting the blank NaCl signal from each chromatogram. Optimized analytical conditions were established in terms of relative standard deviation (%) of retention time, peak area and calibration equations, and also by peak asymmetry factor. The net efflux of K(+) into the gastric lumen under in vitro conditions of acid secretion was investigated in Ussing chamber model. The effects of the physiological secretagogue histamine and the antisecretory agents cimetidine, omeprazole and SCH28080 were studied. The decline of K(+) efflux in presence of cimetidine, and the rise of the same in the presence of omeprazole and SCH28080 were conspicuously discernible, thereby validating the usefulness of ion chromatography based K(+) quantification method under biological experimental conditions.     

Heritability of P. falciparum and P. vivax Malaria in a Karen Population in Thailand

The majority of studies concerning malaria host genetics have focused on individual genes that confer protection against rather than susceptibility to malaria. Establishing the relative impact of genetic versus non-genetic factors on malaria infection and disease is essential to focus effort on key determinant factors. This relative contribution has rarely been evaluated for Plasmodium falciparum and almost never for Plasmodium vivax. We conducted a longitudinal cohort study in a Karen population of 3,484 individuals in a region of mesoendemic malaria, Thailand from 1998 to 2005. The number of P. falciparum and P. vivax clinical cases and the parasite density per person were determined. Statistical analyses were performed to account for the influence of environmental factors and the genetic heritability of the phenotypes was calculated using the pedigree-based variance components model. The genetic contribution to the number of clinical episodes resulting from P. falciparum and P. vivax were 10% and 19% respectively. There was also moderate genetic contribution to the maximum and overall parasite trophozoite density phenotypes for both P. falciparum (16%&16%) and P. vivax (15%&13%). These values, for P. falciparum, were similar to those previously observed in a region of much higher transmission intensity in Senegal, West Africa. Although environmental factors play an important role in acquiring an infection, genetics plays a determinant role in the outcome of an infection with either malaria parasite species prior to the development of immunity.     

Metabolic profiling by <Superscript>1</Superscript>H NMR spectroscopy of saliva shows clear distinction between control and diseased case of periodontitis

Introduction

Periodontitis is a chronic, non-reversible inflammatory disease of the oral cavity leading to destruction of periodontal tissues. Thus, the estimation of bacterial metabolite, tissue damage and secretory metabolites of the triggered inflammatory cells likely to yield results. It may be of value for understanding the pathophysiology of the disease by metabolic profiling of saliva samples using high-resolution NMR spectroscopy.

Objective

The study will evaluate the difference in salivary metabolites in healthy and periodontal condition along with fetching of possible biomarkers in case of chronic periodontitis.

Methods

¹H- NMR spectroscopy has been employed in 114 saliva samples in search of distinctive differences and spectral data were further subjected to multivariate analysis.

Result

One-hundred metabolites were characterised and assigned in the ¹H NMR spectra of saliva. The statistical analysis of control (Healthy subjects) and diseased (Periodontal subjects) using PLS-DA model resulted in R² of 0.84 and Q² of 0.79. There was an elevation in the concentration of statistically discriminant metabolites. The twenty newly identified metabolites in saliva indicates bacterial population shift along with change in homeostasis. These disturbs the biofilm, a real protector against any possible bio-damage on tooth surface. These newly identified metabolites could define better geographically diversified periodontal condition.

Conclusion

Analysis clearly differentiates healthy subjects from the diseased ones. Few newly identified metabolites along with the pool of metabolites may serve as biomarkers for distinguishing the severity and complexity of periodontitis.