Anti-depressant-like activity of a novel serotonin type-3 (5-HT3) receptor antagonist in rodent models of depression

N-Cyclohexyl-3-methoxyquinoxalin-2-carboxamide (QCM-13), a novel 5-HT3 antagonist identified from a series of compounds with higher pA2 (7.6) and good log P (2.91) value was screened in rodent models of depression such as forced swim test (FST), tail suspension test (TST), interaction studies with standard anti-depressants and confirmatory studies such as reversal of parthenolide induced depression and reserpine induced hypothermia. In FST (2 and 4 mg/kg) and TST (2 and 4 mg/kg), QCM-13 significantly reduced the duration of immobility in mice without affecting the base line locomotion. QCM-13 (2 and 4 mg/kg) was also found to have significant interaction with standard anti-depressants (fluoxetine and bupropion in FST and TST respectively). Further, reversal of parthenolide induced depression in mice and reserpine induced hypothermia in rat models indicate the serotonergic influence of QCM-13 for anti-depressant potential.     

N-acetyl-L-cysteine counteracts oxidative stress and prevents H2O2 induced germ cell apoptosis through down-regulation of caspase-9 and JNK/c-Jun

The mechanism of H(2)O(2) induced oxidative stress leading to male germ cell apoptosis was earlier reported from our laboratory. In the present study, we investigated the mechanisms by which N-acetyl-L-cysteine (NAC, which is highly cell specific with strong antioxidant and anti-genotoxic properties), stimulated cell survival under such conditions. Co-incubation with 5 mM NAC significantly (P<0.001) reduced the germ cell apoptosis induced by 10 μM H(2)O(2). Lipid peroxidation was brought down with significant restoration of activities of antioxidant enzymes, SOD, GST, and catalase. Expression of pro-apoptotic marker, Bax up-regulated following H(2)O(2) exposure, was reversed back to control levels. In contrast, expression of anti-apoptotic Bcl-2 and phospho-Akt revealed a completely opposite trend. While caspase-8 activity remained unaffected, NAC successfully attenuated the increased activities of caspase-3 and -9 in the H(2) O(2) treated cells. Simultaneously, the increased expression of caspase-9, phospho-JNK, and phospho-c-Jun after H(2)O(2) treatment was down-regulated by NAC. The above findings indicate that the mechanism of inhibition of H(2)O(2) induced male germ cell apoptosis by NAC is mediated through regulation of caspase-9 and JNK.     

Evidences for differential expression of miR167d-5p,target, positional nucleotide preference,and its role in somatic and different stages of regenerating calli of Oryza sativa

Plant Cell, Tissue and Organ Culture (PCTOC) - The incorporation of important value-added features in rice by Agrobacterium-mediated transformation of scutellum-derived calli is an established...     

An integrated in silico approach to understand protein–protein interactions: human meprin-β with fetuin-A

Abstract

Human meprin-β, a zinc metalloprotease belonging to the astacin family, have been found to be associated with many pathological conditions like inflammatory bowel disease, fibrosis and neurodegenerative disease. The inhibition of meprin-β by various inhibitors, both macromolecular and small molecules, is crucial in the control of several diseases. Human fetuin-A, a negative acute phase protein involved in inflammatory disease, has recently been identified as an endogenous inhibitor for meprin-β. In this computational study, an integrated in silico approach was performed using existing structural information of meprin-β coupled with ab initio modelling of human fetuin-A to predict a rational model of the complex through protein–protein docking. Further, the models were optimized and validated to generate an ensemble of conformations through extensive molecular dynamics simulation. Virtual alanine scanning mutagenesis was explored to identify hotspot residues on both proteins significant for protein–protein interaction (PPI). The results of the study provide structural insight into PPI between meprin-β and fetuin-A which can be useful in designing molecules to modulate meprin-β activity.

Communicated by Ramaswamy H. Sarma     

Modeling the Cost Effectiveness of Neuroimaging-Based Treatment of Acute Wake-Up Stroke

Background

Thrombolytic treatment (tissue-type plasminogen activator [tPA]) is only recommended for acute ischemic stroke patients with stroke onset time <4.5 hours. tPA is not recommended when stroke onset time is unknown. Diffusion-weighted MRI (DWI) and fluid attenuated inversion recovery (FLAIR) MRI mismatch information has been found to approximate stroke onset time with some accuracy. Therefore, we developed a micro-simulation model to project health outcomes and costs of MRI-based treatment decisions versus no treatment for acute wake-up stroke patients.

Methods and Findings

The model assigned simulated patients a true stroke onset time from a specified probability distribution. DWI-FLAIR mismatch estimated stroke onset <4.5 hours with sensitivity and specificity of 0.62 and 0.78, respectively. Modified Rankin Scale (mRS) scores reflected tPA treatment effectiveness accounting for patients’ true stroke onset time. Discounted lifetime costs and benefits (quality-adjusted life years [QALYs]) were projected for each strategy. Incremental cost-effectiveness ratios (ICERs) were calculated for the MRI-based strategy in base-case and sensitivity analyses. With no treatment, 45.1% of simulated patients experienced a good stroke outcome (mRS score 0–1). Under the MRI-based strategy, in which 17.0% of all patients received tPA despite stroke onset times >4.5 hours, 46.3% experienced a good stroke outcome. Lifetime discounted QALYs and costs were 5.312 and $88,247 for the no treatment strategy and 5.342 and $90,869 for the MRI-based strategy, resulting in an ICER of $88,000/QALY. Results were sensitive to variations in patient- and provider-specific factors such as sleep duration, hospital travel and door-to-needle times, as well as onset probability distribution, MRI specificity, and mRS utility values.

Conclusions

Our model-based findings suggest that an MRI-based treatment strategy for this population could be cost-effective and quantifies the impact that patient- and provider-specific factors, such as sleep duration, hospital travel and door-to-needle times, could have on the optimal decision for wake-up stroke patients.     

Synthesis and antibacterial activity of 4,5,6,7-tetrahydro-thieno[3,2-c]pyridine quinolones

Synthesis and antibacterial activity of a number of substituted 4,5,6,7-tetrahydro-thieno[3,2-c]pyridine quinolones is reported. The antibacterial activities were evaluated in standard in vitro MIC assay method. Some of the compounds showed in vitro (MIC) antibacterial activity comparable to those of Gatifloxacin, Ciprofloxacin, and Sparfloxacin.     

Molecular basis of increased serum resistance among pulmonary isolates of non-typeable Haemophilus influenzae

Non-typeable Haemophilus influenzae (NTHi), a common commensal of the human pharynx, is also an opportunistic pathogen if it becomes established in the lower respiratory tract (LRT). In comparison to colonizing isolates from the upper airway, LRT isolates, especially those associated with exacerbations of chronic obstructive pulmonary disease, have increased resistance to the complement- and antibody-dependent, bactericidal effect of serum. To define the molecular basis of this resistance, mutants constructed in a serum resistant strain using the mariner transposon were screened for loss of survival in normal human serum. The loci required for serum resistance contribute to the structure of the exposed surface of the bacterial outer membrane. These included loci involved in biosynthesis of the oligosaccharide component of lipooligosaccharide (LOS), and vacJ, which functions with an ABC transporter encoded by yrb genes in retrograde trafficking of phospholipids from the outer to inner leaflet of the cell envelope. Mutations in vacJ and yrb genes reduced the stability of the outer membrane and were associated with increased cell surface hyrophobicity and phospholipid content. Loss of serum resistance in vacJ and yrb mutants correlated with increased binding of natural immunoglobulin M in serum as well as anti-oligosaccharide mAbs. Expression of vacJ and the yrb genes was positively correlated with serum resistance among clinical isolates. Our findings suggest that NTHi adapts to inflammation encountered during infection of the LRT by modulation of its outer leaflet through increased expression of vacJ and yrb genes to minimize recognition by bactericidal anti-oligosaccharide antibodies.