Secondary metabolites from acridocarpus orientalis inhibits 4T1 cells and promotes mesenchymal stem cells (MSCs) proliferation

Molecular Biology Reports - Among medicinal plants, Acridocarpus orientalis (AO) possesses a remarkable anti-cancer potential, possibly because of its anti-oxidant property. In this study, the leaf...     

Frequent Periodic Leg Movement During Sleep Is an Unrecognized Risk Factor for Progression of Atrial Fibrillation

Sleep apnea has been recognized as a factor predisposing to atrial fibrillation recurrence and progression. The effect of other sleep-disturbing conditions on atrial fibrillation progression is not known. We sought to determine whether frequent periodic leg movement during sleep is a risk factor for progression of atrial fibrillation. In this retrospective study, patients with atrial fibrillation and a clinical suspicion of restless legs syndrome who were referred for polysomnography were divided into two groups based on severity of periodic leg movement during sleep: frequent (periodic movement index >35/h) and infrequent (≤35/h). Progression of atrial fibrillation to persistent or permanent forms between the two groups was compared using Wilcoxon rank-sum test, chi-square tests and logistic regression analysis. Of 373 patients with atrial fibrillation (77% paroxysmal, 23% persistent), 108 (29%) progressed to persistent or permanent atrial fibrillation during follow-up (median, 33 months; interquartile range, 16-50). Compared to patients with infrequent periodic leg movement during sleep (n=168), patients with frequent periodic leg movement during sleep (n=205) had a higher rate of atrial fibrillation progression (23% vs. 34%; p=0.01). Patients with frequent periodic leg movement during sleep were older and predominantly male; however, there were no significant differences at baseline in clinical factors that promote atrial fibrillation progression between both groups. On multivariate analysis, independent predictors of atrial fibrillation progression were persistent atrial fibrillation at baseline, female gender, hypertension and frequent periodic leg movement during sleep. In patients with frequent periodic leg movement during sleep, dopaminergic therapy for control of leg movements in patients with restless legs syndrome reduced risk of atrial fibrillation progression. Frequent leg movement during sleep in patients with restless legs syndrome is associated with progression of atrial fibrillation to persistent and permanent forms.     

Kinetic Studies on the Inhibition of GABA-T by γ-Vinyl GABA and Taurine

γ-Aminobutyric acid transaminase (GABA-T, EC 2.6.1.19) is a pyridoxal phosphate (PLP) dependent enzyme that catalyzes the degradation of γ-aminobutyric acid. The kinetics of this reaction are studied in vitro, both in the absence, and in the presence of two inhibitors: γ-vinyl GABA (4-aminohex-5-enoic acid), and a natural product, taurine (ethylamine-2-sulfonic acid). A kinetic model that describes the transamination process is proposed. GABA-T from Pseudomonas fluorescens is inhibited by γ-vinyl GABA and taurine at concentrations of 51.0 and 78.5?mM. Both inhibitors show competitive inhibition behavior when GABA is the substrate and the inhibition constant (K_i) values for γ-vinyl GABA and taurine were found to be 26±3?mM and 68±7?mM respectively. The transamination process of α-ketoglutarate was not affected by the presence of γ-vinyl GABA, whereas, taurine was a noncompetitive inhibitor of GABA-T when α-ketoglutarate was the substrate. The inhibition dissociation constant (K_ii) for this system was found to be 96±10?mM. The Michaelis-Menten constant (K_m) in the absence of inhibition, was found to be 0.79±0.11?mM, and 0.47±0.10?mM for GABA and α-ketoglutarate respectively.     

The VHL gene is epigenetically inactivated in pheochromocytomas and abdominal paragangliomas

Pheochromocytoma (PCC) and abdominal paraganglioma (PGL) are neuroendocrine tumors that present with clinical symptoms related to increased catecholamine levels. About a third of the cases are associated with constitutional mutations in pre-disposing genes, of which some may also be somatically mutated in sporadic cases. However, little is known about inactivating epigenetic events through promoter methylation in these very genes. Using bisulphite pyrosequencing we assessed the methylation density of 11 PCC/PGL disease genes in 96 tumors (83 PCCs and 13 PGLs) and 34 normal adrenal references. Gene expression levels were determined by quantitative RT-PCR. Both tumors and normal adrenal samples exhibited low methylation index (MetI) in the EGLN1 (PDH2), MAX, MEN1, NF1, SDHB, SDHC, SDHD, SDHAF2 (SDH5), and TMEM127 promoters, not exceeding 10% in any of the samples investigated. Aberrant RET promoter methylation was observed in two cases only. For the VHL gene we found increased MetI in tumors as compared with normal adrenals (57% vs. 27%; P < 0.001), in malignant vs. benign tumors (63% vs. 55%; P < 0.05), and in PGL vs. PCC (66% vs. 55%; P < 0.0005). Decreased expression of the VHL gene was observed in all tumors compared with normal adrenals (P < 0.001). VHL MetI and gene expressions were inversely correlated (R = −0.359, P < 0.0001). Our results show that the VHL gene promoter has increased methylation compared with normal adrenals (MetI > 50%) in approximately 75% of PCCs and PGLs investigated, highlighting the role of VHL in the development of these tumors.     

Evaluation of effect of high frequency electromagnetic field on growth and antibiotic sensitivity of bacteria

This study was aimed to evaluate the impact of high frequency electromagnetic fields (HF-EMF at 900 and 1800 MHz) on DNA, growth rate and antibiotic susceptibility of S. aureus, S. epidermidis, and P. aeruginosa. In this study, bacteria were exposed to 900 and 1800 MHz for 2 h and then inoculated to new medium when their growth rate and antibiotic susceptibility were evaluated. Results for the study of bacterial DNA unsuccessful to appearance any difference exposed and non-exposed S. aureus and S. epidermidis. Exposure of S. epidermidis and S. aureus to electromagnetic fields mostly produced no statistically significant decrease in bacterial growth, except for S. aureus when exposure to 900 MHz at 12 h. Exposure of P. aeruginosa to electromagnetic fields at 900 MHz however, lead to a significant reduction in growth rate, while 1800 MHz had insignificant effect. With the exception of S. aureus, treated with amoxicillin (30 µg) and exposed to electromagnetic fields, radiation treatment had no significant effect on bacterial sensitivity to antibiotics.     

Molecular players of auxin transport systems: advances in genomic and molecular events*

Phytohormone auxin plays an indispensable role in the plethora of plant developmental process starting from the cell division, and cell elongation to morphogenesis. Auxins are transported to different parts of the plant by different sophisticated transporter molecules known as ‘auxin transporters’.There are four auxin transporter families that have been reported so far in the plant kingdom which includes AUX/LAX (AUXIN-RESISTANT1–LIKES), PIN (PIN-FORMED, auxin efflux carriers), ABCB ((ATP-binding cassette-B (ABCB)/P-glycoprotein (PGP)) and PILS (PIN-Likes). Auxin influx and efflux carriers are distributed in a polar fashion in the plasma membrane whereas ABCB and PILS are present in a non-polar fashion. Other than AUX/LAX, other auxin transporters harbor N-and C-terminal conserved domains along with a variable hydrophilic loop in the transmembrane domain. The AUX/LAX, ABCB and PIN transporters mediate long distance auxin transport whereas PILS and PIN5 protein involved in intracellular auxin homeostasis.     

Trisubstituted-Imidazoles Induce Apoptosis in Human Breast Cancer Cells by Targeting the Oncogenic PI3K/Akt/mTOR Signaling Pathway

Overactivation of PI3K/Akt/mTOR is linked with carcinogenesis and serves a potential molecular therapeutic target in treatment of various cancers. Herein, we report the synthesis of trisubstituted-imidazoles and identified 2-chloro-3-(4, 5-diphenyl-1H-imidazol-2-yl) pyridine (CIP) as lead cytotoxic agent. Naïve Base classifier model of in silico target prediction revealed that CIP targets RAC-beta serine/threonine-protein kinase which comprises the Akt. Furthermore, CIP downregulated the phosphorylation of Akt, PDK and mTOR proteins and decreased expression of cyclin D1, Bcl-2, survivin, VEGF, procaspase-3 and increased cleavage of PARP. In addition, CIP significantly downregulated the CXCL12 induced motility of breast cancer cells and molecular docking calculations revealed that all compounds bind to Akt2 kinase with high docking scores compared to the library of previously reported Akt2 inhibitors. In summary, we report the synthesis and biological evaluation of imidazoles that induce apoptosis in breast cancer cells by negatively regulating PI3K/Akt/mTOR signaling pathway.     

Factors affecting <Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation in <Emphasis Type="Italic">Hybanthus</Emphasis><Emphasis Type="Italic">enneaspermus</Emphasis> (L.) F. Muell.

Agrobacterium tumefaciens-mediated transformation system was established for Hybanthus enneaspermus using leaf explants with the strain LBA4404 harbouring pCAMBIA 2301 carrying the nptII and gusA genes. Sensitivity of leaf explants to kanamycin was standardized (100 mg/l) for screening the transgenic plants. Transformation parameters (OD, virulence inducer, infection time, co-cultivation period, bactericidal antibiotics, etc.) influencing the gene transfer and integration were assessed in the present investigation. Fourteen-day pre-cultured explants were subjected with Agrobacterium strain LBA4404. Optimized parameters such as culture density of 0.5 OD₆₀₀, infection time of 6 min, AS concentration of 150 µM with 3 days co-cultivation revealed maximum transformation efficiency based on GUS expression assay. The presence of gusA in transgenics was confirmed by polymerase chain reaction and Southern blotting analysis. The present transformation experiment yielded 20 shoots/explant with higher transformation efficiency (28 %). The protocol could be used to introduce genes for trait improvement as well as for altering metabolic pathway for secondary metabolites production.     

Phylogenetic relationships of Danio within the order Cypriniformes: a framework for comparative and evolutionary studies of a model species

The evolutionary relationships of species of Danio and the monophyly and phylogenetic placement of the genus within the family Cyprinidae and subfamily Rasborinae provide fundamentally important phyloinformatics necessary for direct evaluations of an array of pertinent questions in modern comparative biology. Although the genus Danio is not one of the most diverse within the family, Danio rerio is one of the most important model species in biology. Many investigations have used this species or presumed close relatives to address specific questions that have lasting impact on the hypothesis and theory of development in vertebrates. Largely lacking from this approach has been a holistic picture of the exact phylogenetic or evolutionary relationships of this species and its close relatives. One thing that has been learned over the previous century is that many organismal attributes (e.g., developmental pathways, ecologies, behaviors, speciation) are historically constrained and their origins and functions are best explained via a phylogenetic approach. Herein, we provide a molecular evaluation of the phylogenetic placement of the model species Danio rerio within the genus Danio and among hypothesized closely related species and genera. Our analysis is derived from data using two nuclear genes (RAG1, rhodopsin) and five mitochondrial genes (ND4, ND4L, ND5, COI, cyt b) evaluated using parsimony, maximum likelihood, and Bayesian analyses. The family Cyprinidae is resolved as monophyletic but the subfamily Rasborinae (priority over Danioinae) is an unnatural assemblage. Danio is identified as a monophyletic group sister to a clade inclusive of the genera Chela, Microrasbora, Devario, and Inlecypris, not Devario nor Esomus as hypothesized in previous studies. Danio rerio is sister to D. kyathit among the species of Danio evaluated in this analysis. Microrasbora and Rasbora are non-monophyletic assemblages; however, Boraras is monophyletic.     

Mediation of burn-induced hypermetabolism by CRF receptor-2 activity

Hypermetabolism and anorexia are significant problems associated with major burn trauma. Recent studies have implicated hypothalamic peptides and receptors of the corticotropin releasing factor (CRF) family as putative mediators of burn-induced hypermetabolism. Increased neuronal activity at the CRF type 2 receptor (CRF R-2) appeared particularly involved in the expression of elevated resting energy expenditure (REE) following major burn trauma. In the present study we continued these investigations of CRF R-2 mediation of burn-induced hypermetabolism, demonstrating that 3rd ventricle injection of CRF R-2 antisense oligodeoxynucleotide (ODN) normalized REE in burned rats. Similar treatments with CRF or CRF R-1 antisense ODNs had no significant effect in burned rats. In addition, 3rd ventricle injection of the selective CRF R-2 antagonist, antisauvagine-30, also reduced REE significantly in burned rats, while similar treatment with the selective CRF R-1 antagonist, antalarmin, was without effect. To determine which endogenous peptide was altered following burn we measured hypothalamic levels of urocortin (UCN) and CRF 15 days after burn injury, finding UCN was significantly elevated by nearly 3-fold, while CRF level tended to be decreased. We also assessed hypothalamic mRNA peptide and receptor expression by real-time PCR 7, 14, and 21 days post-burn, observing decreased CRF expression 7 and 21 days post-burn, decreased UCN-2 expression 7 days post-burn, and no significant alteration in UCN-1 at any time point. However, CRF R-2 mRNA was elevated at each post-burn time point. These results continue to suggest that increased neuronal activity is integrally involved in the mediation of burn-induced hypermetabolism, and that one of the UCN peptides may be the endogenous ligand affecting this receptor.