Glutathione-S-transferase P1 is a critical regulator of Cdk5 kinase activity

Cyclin dependent kinase-5 (Cdk5) activity is deregulated in Alzheimer's disease (AD) and contributes to all three hallmarks: neurotoxic β-amyloid formation, neurofibrillary tangles, and neuronal death. However, the mechanism leading to Cdk5 deregulation remains controversial. Cdk5 deregulation in AD is usually linked to the formation of p25, a proteolysis product of Cdk5 activator p35, which leads to Cdk5 mislocalization and hyperactivation. A few studies have indeed shown increased p25 levels in AD brains; however, others have refuted this observation. These contradictory findings suggest that additional factors contribute to Cdk5 deregulation. This study identified glutathione-S-transferase pi 1 (GSTP1) as a novel Cdk5 regulatory protein. We demonstrate that it is a critical determinant of Cdk5 activity in human AD brains and various cancer and neuronal cells. Increased GSTP1 levels were consistently associated with reduced Cdk5 activity. GSTP1 directly inhibits Cdk5 by dislodging p25/p35, and indirectly by eliminating oxidative stress. Cdk5 promotes and is activated by oxidative stress, thereby engaging a feedback loop which ultimately leads to cell death. Not surprisingly, GSTP1 transduction conferred a high degree of neuroprotection under neurotoxic conditions. Given the critical role of oxidative stress in AD pathogenesis, an increase in GSTP1 level may be an alternative way to modulate Cdk5 signaling, eliminate oxidative stress, and prevent neurodegeneration.     

Diet and cancer prevention: Dietary compounds,dietary MicroRNAs,and dietary exosomes

Cancer is one of main health public problems worldwide. Several factors are involved in beginning and development of cancer. Genetic and internal/external environmental factors can be as important agents that effect on emerging and development of several cancers. Diet and nutrition may be as one of important factors in prevention or treatment of various cancers. A large number studies indicated that suitable dietary patterns may help to cancer prevention or could inhibit development of tumor in cancer patients. Moreover, a large numbers studies indicated that a variety of dietary compounds such as curcumin, green tea, folat, selenium, and soy isoflavones show a wide range anti‐cancer properties. It has been showed that these compounds via targeting a sequence of cellular and molecular pathways could be used as suitable options for cancer chemoprevention and cancer therapy. Recently, dietary microRNAs and exosomes have been emerged as attractive players in cancer prevention and cancer therapy. These molecules could change behavior of cancer cells via targeting various cellular and molecular pathways involved in cancer pathogenesis. Hence, the utilization of dietary compounds which are associated with powerful molecules such as microRNAs and exosomes and put them in dietary patterns could contribute to prevention or treatment of various cancers. Here, we summarized various studies that assessed effect of dietary patterns on cancer prevention shortly. Moreover, we highlighted the utilization of dietary compounds, dietary microRNAs, and dietary exosomes and their cellular and molecular pathways in cancer chemoprevention.     

Genomic,Proteomic, Morphological,and Phylogenetic Analyses of vB_EcoP_SU10, a Podoviridae Phage with C3 Morphology

A recently isolated phage, vB_EcoP_SU10 (SU10), with the unusual elongated C3 morphotype, can infect a wide range of Escherichia coli strains. We have sequenced the genome of this phage and characterized it further by mass spectrometry based proteomics, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and ultra-thin section electron microscopy. The genome size is 77,327 base pairs and its genes, and genome architecture, show high similarity to the phiEco32 phage genes and genome. The TEM images reveal that SU10 have a quite long tail for being a Podoviridae phage, and that the tail also changes conformation upon infection. The ultra-thin section electron microscopy images of phages at the stage of replication within the host cell show that the phages form a honeycomb-like structure under packaging of genomes and assembly of mature capsids. This implies a tight link between the replication and cutting of the concatemeric genome, genome packaging, and capsid assembly. We have also performed a phylogenetic analysis of the structural genes common between Podoviridae phages of the C1 and C3 morphotypes. The result shows that the structural genes have coevolved, and that they form two distinct groups linked to their morphotypes. The structural genes of C1 and C3 phages appear to have diverged around 280 million years ago applying a molecular clock calibrated according to the presumed split between the Escherichia – Salmonella genera.     

Three phases hollow fiber LPME combined with HPLC-UV for extraction, preconcentration and determination of valerenic acid in Valeriana officinalis

In the present work, the applicability of hollow fiber-based liquid phase microextraction (HF-LPME) was evaluated for the extraction and preconcentration of valerenic acid prior to its determination by reversed-phase HPLC/UV. The target drug was extracted from 5.0 mL of aqueous solution with pH 3.5 into an organic extracting solvent (dihexyl ether) impregnated in the pores of a hollow fiber and finally back extracted into 10 μ L of aqueous solution with pH 9.5 located inside the lumen of the hollow fiber. In order to obtain high extraction efficiency, the parameters affecting the HF-LPME, including pH of the donor and acceptor phases, type of organic phase, ionic strength, the volume ratio of donor to acceptor phase, stirring rate and extraction time were studied and optimized. Under the optimized conditions, enrichment factor up to 446 was achieved and the relative standard deviation (RSD) of the method was 4.36% (n = 9). The linear range was 7.5-850 μg L?1 with correlation coefficient (r2=0.999), detection limits was 2.5 μg L?1 and the LOQ was 7.5 μg L?1. The proposed method was evaluated by extraction and determination of valerenic acid in some Iranian wild species of Valerianaceae.     

Surface display of organophosphorus hydrolase on E. coli using N-terminal domain of ice nucleation protein InaV

Recombinant Escherichia coli displaying organophosphorus hydrolase (OPH) was used to overcome the diffusion barrier limitation of organophosphorus pesticides. A new anchor system derived from the N-terminal domain of ice-nucleation protein from Pseudomonas syringae InaV (InaV-N) was used to display OPH onto the surface. The designed sequence was cloned in the vector pET-28a(+) and then was expressed in E. coli. Tracing of the expression location of the recombinant protein using SDS-PAGE showed the presentation of OPH by InaV-N on the outer membrane, and the ability of recombinant E. coli to utilize diazinon as the sole source of energy, without growth inhibition, indicated its significant activity. The location of OPH was detected by comparing the activity of the outer membrane fraction with the inner membrane and cytoplasm fractions. Studies revealed that recombinant E. coli can degrade 50% of 2 mM chlorpyrifos in 2 min. It can be concluded that InaV-N can be used efficiently to display foreign functional protein, and these results highlight the high potential of an engineered bacterium to be used in bioremediation of pesticide-contaminated sources in the environment.     

Factors affecting the occurrence of postpartum prolonged luteal activity in clinically healthy high-producing dairy cows

The objective was to characterize risk factors affecting the occurrence of prolonged luteal phase (PLP) in postpartum, clinically healthy, high-producing dairy cows. Transrectal ultrasound examinations of the reproductive tract were performed twice weekly, from the 1st to 8th wk after calving in 151 multiparous clinically healthy lactating Holstein cows (mean ± SD of peak milk yield = 56.7 ± 7.4 kg). Serum samples were collected twice weekly to measure progesterone and every 2 wk to detect β-hydroxybutyrate (βHB), and α1-acid glycoprotein (AGP). Body condition score (BCS) was recorded weekly after calving. Based on the serum progesterone profile, 52 (34.4%) cows had normal ovarian activity (NLA), whereas 36 (23.8%) cows had a prolonged luteal phase (PLP), the most prevalent type of abnormal pattern of luteal activity. Furthermore, 63 cows with short luteal activity, delayed first ovulation, or cystic ovaries were excluded from this study. Serum AGP concentrations, as an indication of postpartum chronic endometritis, were not different (P > 0.05) between cows with NLA and PLP. Categories of peak milk yields (kg) were positively correlated with the incidence (%) of cows with PLP (r = 0.87, P = 0.02). Furthermore, milk yield peak, day of milk yield peak, mean milk yield (8 wk in milk), and milk yield on the expected day of luteolysis were higher (P < 0.05) in cows with PLP than NLA, and cows with PLP had greater loss of BCS (P = 0.007) than those with NLA. The likelihood of cows with PLP decreased by 0.9-fold for every 1 d delay of commencement of luteal activity (C-LA). Moreover, the likelihood of cows with PLP increased by 1.8-fold for each 1 mmol/L increase in the 1st wk serum βHB concentrations. In conclusion, higher mean of milk yield, greater BCS loss, earlier C-LA, and later peak milk yield were the major risk factors affecting the occurrence of postpartum PLP in clinically healthy, high-producing dairy cows.     

PloGO: plotting gene ontology annotation and abundance in multi-condition proteomics experiments

We describe the PloGO R package, a simple open-source tool for plotting gene ontology (GO) annotation and abundance information, which was developed to aid with the bioinformatics analysis of multi-condition label-free proteomics experiments using quantitation based on spectral counting. PloGO can incorporate abundance (raw spectral counts) or normalized spectral abundance factors (NSAF) data in addition to the GO annotation, as well as handle multiple files and allow for a targeted collection of GO categories of interest. Our main aims were to help identify interesting subsets of proteins for further analysis such as those arising from a protein data set partition based on the presence and absence or multiple pair-wise comparisons, as well as provide GO summaries that can be easily used in subsequent analyses. Though developed with label-free proteomics experiments in mind it is not specific to that approach and can be used for any multi-condition experiment for which GO information has been generated.     

Effects of whole body vibration on outer hair cells’ hearing response to distortion product otoacoustic emissions

Whole body vibration (WBV) is one of the most vexing problems in industries. There is a debate about the effect of WBV exposure on hearing system as vibration-induced hearing loss. The purpose of this study was to investigate outer hair cells' (OHCs') hearing response hearing response to distortion product otoacoustic emissions (DPOAEs) in rabbits exposed to WBV. It was hypothesized that the DPOAE response amplitudes (A(dp)) in rabbits exposed to WBV would be lower than those in control rabbits not exposed to WBV. New Zealand white (NZW) rabbits as vibration group (n = 6, exposed to WBV in the z-axis at 4-8 Hz and 1.0 ms(-2) root mean square for 8 h per day during five consecutive days) and NZW rabbits as control group (n = 6, not exposed to any WBV) were participated. A(dp) and noise floor levels (L(nf)) were examined on three occasions: day 0 (i.e., baseline), day 8 (i.e., immediately 1 h after exposure), and day 11 (i.e., 72 h following exposure) with f(2) frequencies ranging from 500 to 10,000 Hz and primaries L(1) and L(2) levels of 65 and 55 dB sound pressure level, respectively. Main effects were statistically found to be significant for group, time, and frequency (p < 0.05). DPOAE amplitudes were significantly larger for rabbits exposed to WBV, larger on day 8 and larger for mid to high f(2) frequencies (at and above 5,888.50 Hz). Main effects were not statistically found to be significant for ear (p > 0.05). Also, four statistically significant interactions including time by ear, time by frequency, group by frequency, and group by time were detected (p < 0.05). Contrary to the main hypothesis, DPOAE amplitudes were significantly larger for rabbits exposed to WBV. WBV exposure significantly led to enhanced mean A(dp) at mid to high frequencies rather than at low ones.     

Genetic and Phenotypic Diversity among Botrytis cinerea Isolates in Iran

Forty-four Botrytis cinerea isolates from different hosts and geographical regions were studied for colony morphology, mycelial growth rate at different temperatures, pathogenicity and molecular diversity. Botrytis cinerea isolates had temperature optima of 20–25°C and isolates showed variation in growth rate at different temperatures. Two morphological types were identified among tested isolates: mycelial and sclerotial. The pathogenicity of isolates was tested on grapevine leaves, and it was revealed that nine of 44 isolates were non-pathogenic and among them seven were of mycelial type. There was no correlation between mycelium growth rate and pathogenicity. Genetic diversity was investigated using nine arbitrary decaprimers. No relationship was found between molecular clusters and geographical region or sampling time; whereas isolates from the same plant host tended to cluster with each other. Seven of nine non-pathogenic isolates were separated from pathogenic ones.