Cold-induced physiological and biochemical responses of three grapevine cultivars differing in cold tolerance

In this study the cold tolerance potential of three Vitis vinifera cultivars including ‘Red Sultana’, ‘White Sultana,’ and ‘Flame Seedless’ was evaluated under greenhouse condition. After 15 leaves stage in average, the grapevine plants were subjected to cold stress regimes (4, 0 and ? 4 °C) and compared with control plants (24 °C). A clear increase in leaf electrolyte leakage (EL), thiobarbituric acid reactive substances (TBARS), and H₂O₂ concentrations was observed with decreasing temperature from 4 to ? 4 °C in all grapevine cultivars. Chilled plants showed marked increases in their abscisic acid (ABA), soluble sugars, and proline contents in compared to control vines. Upon exposure to cold stress, the EL, TBARS, H₂O₂, and relative water content of ‘Red Sultana’ were found to be lower compared to ‘White Sultana’ and ‘Flame Seedless’. Under 0 °C condition, ‘Red Sultana’ had the highest superoxide dismutase, guaiacol peroxidase and catalase activities, which was approximately twofold higher than those of all other cultivars. Soluble sugars such as glucose, fructose, and sucrose increased from 4 to ? 4 °C. These increments were higher in ‘Red Sultana’ compared to other cultivars which was concomitant with higher accumulation of endogenous ABA concentration in this cultivar. Higher accumulation of ABA and soluble sugars in ‘Red Sultana’ confirmed the key roles of these compounds in cold tolerance which could be applied as a cold tolerance marker for early selection of grapevine cultivars with the aim to establish vineyards in cold winter regions.     

Delivery of HIV-1 Nef Protein in Mammalian Cells Using Cell Penetrating Peptides as a Candidate Therapeutic Vaccine

The HIV-1 Nef protein expressed early in viral life cycle has been known as a potent candidate for therapeutic vaccine development. Due to different cell barriers, various cell penetrating peptides (CPPs) such as Pep-1 and CADY-2 have been known to deliver biologically active proteins to cytoplasmic compartments via the plasma membrane. In current study, we firstly evaluated the efficiency of lentiviral vector (pCDH-CMV-MCS-EF1-cGFP-T2A-puro) and eukaryotic expression vector (pEGFP-N1) for expression of HIV-1 Nef protein in HEK-293T cells using TurboFect transfection reagent. Our results showed that both vectors can effectively express the Nef proteins within the target cell. The pEGFP-N1 was more effective than pCDH-GFP for protein expression. Furthermore, Nef protein was expressed in E. coli as GST-Nef fusion and transfected by the amphipathic CPPs including Pep-1 and CADY-2 into HEK-293T cells. The size and morphology of the GST-Nef/CPP complexes were evaluated by scanning electron microscopy, and Zetasizer. Our data indicated that the recombinant GST-Nef protein generated in BL21 strain migrated as a clear band of ~50 kDa in SDS-PAGE. The CPP/GST-Nef nanoparticles were formed with a diameter of below 200 nm and notably delivered into HEK-293T cells. Generally, the Nef protein was expressed in prokaryotic and eukaryotic expression systems using different vectors and efficiently transfected in mammalian cells using various delivery systems. The in vitro efficient delivery of HIV-1 Nef gene and also its protein supports the potential of Nef DNA constructs and CPPs as potent carriers of Nef protein for HIV vaccine design in Future.     

Measurement of opsonophagocytic activity of antibodies specific toNeisseria meningitidis serogroup A capsular polysaccharide-serogroup B outer membrane vesicle conjugate in animal model

Neisseria meningitidis is efficiently phagocytosed by polymorphonuclear leukocytes (PMNS) following opsonization with opsonic antibodies; opsonophagocytosis is the primary mechanism for clearance of meningococci from the host. Thus, in testing meningococcal vaccines, the level of opsonophagocytic antibodies appears to correlate with vaccine-induced protection. Our previous studies demonstrated that the conjugation ofN. meningitidis serogroup A capsular polysaccharide (CPSA) to serogroup B outer membrane vesicle (OMV) could induce a high level of bactericidal antibody response against serogroup A meningococci in animals. The purpose of this study was to evaluate opsonophagocytic activity of the conjugate of CPSA to OMV (CPSA-OMV). In order to evaluate the potential efficacy of CPSA-OMV a flow cytometric opsonophagocytic assay was used. The conjugate and controls were injected intramuscularly into four groups of rabbits with boosters on days 14, 28 and 42 following primary immunization. The rabbits were bled prior to injection and two weeks after each injection. Opsonophagocytic activity of antibodies in hyperimmune sera through rabbit PMNS were measured with flow cytometer, using dihydrorhodamine-123 as a probe. The results indicated that our conjugate could induce a highly significant level of opsonophagocytic activity against serogroup A meningococci after 56 days compared to the control groups (P<0.05). We conclude that this conjugate represents a vaccine candidate against serogroups A and B meningococci after further investigation.     

Kavosh: a new algorithm for finding network motifs

Background  

Complex networks are studied across many fields of science and are particularly important to understand biological processes. Motifs in networks are small connected sub-graphs that occur significantly in higher frequencies than in random networks. They have recently gathered much attention as a useful concept to uncover structural design principles of complex networks. Existing algorithms for finding network motifs are extremely costly in CPU time and memory consumption and have practically restrictions on the size of motifs.     

Systematic analysis of insertions and deletions specific to nematode proteins and their proposed functional and evolutionary relevance

Background  

Amino acid insertions and deletions in proteins are considered relatively rare events, and their associations with the evolution and adaptation of organisms are not yet understood. In this study, we undertook a systematic analysis of over 214,000 polypeptides from 32 nematode species and identified insertions and deletions unique to nematode proteins in more than 1000 families and provided indirect evidence that these alterations are linked to the evolution and adaptation of nematodes.     

Regulation of BMAL1 Protein Stability and Circadian Function by GSK3β-Mediated Phosphorylation

Background

Circadian rhythms govern a large array of physiological and metabolic functions. To achieve plasticity in circadian regulation, proteins constituting the molecular clock machinery undergo various post-translational modifications (PTMs), which influence their activity and intracellular localization. The core clock protein BMAL1 undergoes several PTMs. Here we report that the Akt-GSK3β signaling pathway regulates BMAL1 protein stability and activity.

Principal Findings

GSK3β phosphorylates BMAL1 specifically on Ser 17 and Thr 21 and primes it for ubiquitylation. In the absence of GSK3β-mediated phosphorylation, BMAL1 becomes stabilized and BMAL1 dependent circadian gene expression is dampened. Dopamine D2 receptor mediated signaling, known to control the Akt-GSK3β pathway, influences BMAL1 stability and in vivo circadian gene expression in striatal neurons.

Conclusions

These findings uncover a previously unknown mechanism of circadian clock control. The GSK3β kinase phosphorylates BMAL1, an event that controls the stability of the protein and the amplitude of circadian oscillation. BMAL1 phosphorylation appears to be an important regulatory step in maintaining the robustness of the circadian clock.     

Vibrio cholerae O139 persists in Dhaka,Bangladesh since 1993

BackgroundAfter a multi-country Asian outbreak of cholera due to Vibrio cholerae serogroup O139 which started in 1992, it is rarely detected from any country in Asia and has not been detected from patients in Africa.Methodology/Principal findingsWe extracted surveillance data from the Dhaka and Matlab Hospitals of International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) to review trends in isolation of Vibrio cholerae O139 in Bangladesh. Data from the Dhaka Hospital is a 2% sample of > 100,000 diarrhoeal patients treated annually. Data from the Matlab Hospital includes all diarrhoeal patients who hail from the villages included in the Matlab Health and Demographic Surveillance System. Vibrio cholerae O139 was first isolated in Dhaka in 1993 and had been isolated every year since then except for a gap between 2005 and 2008. An average of thirteen isolates was detected annually from the Dhaka Hospital during the last ten years, yielding an estimated 650 cases annually at this hospital. During the last ten years, cases due to serogroup O139 represented 0.47% of all cholera cases; the others being due to serogroup O1. No cases with serogroup O139 were identified at Matlab since 2006. Clinical signs and symptoms of cholera due to serogroup O139 were similar to cases due to serogroup O1 though more of the O139 cases were not dehydrated. Most isolates of O139 remained sensitive to tetracycline, ciprofloxacin, and azithromycin, but they became resistant to erythromycin starting in 2009.Conclusions/SignificanceCholera due to Vibrio cholerae serogroup O139 continues to cause typical cholera in Dhaka, Bangladesh.     

Hematological changes in Florida pompano (Trachinotus carolinus) supplemented with β-glucan and Pediococcus acidilactici synbiotic

Florida pompano (Trachinotus carolinus) are a species of growing interest for commercial aquaculture. Effective health monitoring is crucial to the successful growout of the species, and prophylactic and therapeutic use of chemicals and antibiotics has been the traditional strategy for promoting stock health. However, concerns about antimicrobial resistance, chemical residues in seafood products and the environment, and resultant immunosuppression have prompted the industry to identify alternative management strategies, including supplementation with prebiotics, probiotics, and combinations of both (synbiotics). The objectives of this study are to determine and compare hematological, plasma biochemical, and plasma protein electrophoresis data of synbiotic-supplemented (β-glucan and Pediococcus acidilactici) and non-supplemented Florida pompano. Reference intervals for blood analytes are provided for both groups and for subgroups (females, males, large, and small fish) where statistically significant results exist. There are no differences between the hematological and plasma biochemistry analytes between the supplemented and control groups, except for blood urea nitrogen and carbon dioxide, indicating a possible effect of synbiotic supplementation on gill function and osmoregulation. Sex-related and size-related differences are observed within each of the control and supplemented groups; however, biometric measurements do not strongly correlate with blood analytes. These data represent baseline hematological and plasma biochemical data in the Florida pompano and indicate the safety of synbiotic supplementation in this commercially important species. This study serves to further the commercialization of Florida pompano by providing blood analyte reference intervals for health monitoring in the aquaculture setting.     

A molecular evaluation of dengue virus pathogenesis and its latest vaccine strategies

More than one third of the world’s population living in tropical and subtropical areas of the world is at risk of dengue infections and as many as 100 million people are yearly infected. This disease has reemerged during the past 20 years in the form of an epidemic. Dengue is caused by one of four related serotypes of dengue virus and often leads to severe forms of the disease, resulting commonly from secondary infections. Dengue virus is a mosquito borne virus, belongs to the family Flaviviridae and consists of a single stranded positive sense RNA genome. Like other RNA viruses it escapes defense mechanisms and neutralization attempts by mutations, which make it more resistant and adaptable to its environment. Antiviral strategies and vaccine development is thus impaired and hence to date there is no licensed vaccine available for dengue virus. Here we discuss various efforts made towards the identification of potential vaccine targets for dengue as well as various strategies employed by research groups/pharmaceutical companies towards the development of a successful dengue vaccine.