New Insight into the Interactions of Arbutin with Mushroom Tyrosinase

The Protein Journal - As a safe substitute for hydroquinone, β-arbutin, a natural plant substance, and its synthetic counterpart, α-arbutin, are used in depigmentation formulations....     

The roles of Groucho/Tle in left-right asymmetry and Kupffer's vesicle organogenesis

The heart is the first organ to form and function in the vertebrate embryo. Furthermore, differences between the left and right sides of the embryo become first detectable during cardiac development. We observed strong cardiac laterality phenotypes in medaka embryos by manipulating Groucho protein activity. The phenotypes produced by misexpressing Tle4 and the dominant-negative Aes reveal a general effect of these corepressor proteins on left-right (LR) development. With the help of an inducible expression system, we were able to define temporally different phases for these effects. In an early phase during gastrulation, Groucho proteins regulate Brachyury expression in the dorsal forerunner cells, which later gives rise to the Kupffer's vesicle (KV). The interference of endogenous Groucho proteins by misexpression of Aes leads to KVs of reduced size, whereas overexpression of Tle4 results in enlarged KVs. The expression level of the cilia marker Lrd was also affected both positively and negatively from these treatments. In the late phase during somitogenesis, Groucho proteins regulate the asymmetric activities of Nodal and Lefty genes. Altering canonical Wnt signaling produced similar results in late embryos, however, this did not affect KV morphogenesis or Lrd expression in early embryos. Therefore, changes in Kupffer's vesicle morphogenesis and the laterality of visceral organs following alterations in Groucho corepressor levels demonstrate two distinct phases in which Groucho proteins help establish LR asymmetry in medaka fish.     

Novel trastuzumab-DM1 conjugate: Synthesis and bio-evaluation

Antibody-drug conjugates are now of considerable interest and are recommended for the treatment of cancers. Linkers are having a crucial role in potency and efficacy of these drugs. Herein, for the first time, we have used a water-soluble poly-ethylene glycol based linker (succinimidyl-[(N-maleimido propionamido)-diethyleneglycol] [SM(PEG)2]) for lysine amide coupling of DM1 drug to trastuzumab considering evaluation of the effect of using a hydrophilic linker on physicochemical and biological properties of the resulting conjugate in comparison to the conjugate containing succinimidyl 4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC) linker, which has a relative hydrophobic nature. The physicochemical properties of synthesized conjugates were investigated in terms of drug to antibody ratio, size variants and free drug quantities. In vitro biological activity of trastuzumab-DM1 conjugates was assessed on breast cancer cell lines expressing different levels of HER2 using binding affinity, antiproliferative, apoptosis, and antibody-dependent cell-mediated cytotoxicity (ADCC) assays. Synthesized conjugate containing hydrophilic linker, showed higher drug to antibody ratio, no aggregated form and higher cellular toxicity in comparison to SMCC bearing conjugate. Binding affinity and ADCC potential of conjugates was not affected upon the usage of hydrophilic linker. In conclusion, application of SM(PEG)2 for coupling of DM1 to trastuzumab enhance desirable characteristics of the resulting conjugate.     

The role of microRNAs in prostate cancer migration,invasion, and metastasis

Prostate cancer (PCa) is considered the most prevalent malignancy and the second major cause of cancer-related death in males from Western countries. PCa exhibits variable clinical pictures, ranging from dormant to highly metastatic cancer. PCa suffers from poor prognosis and diagnosis markers, and novel biomarkers are required to define disease stages and to design appropriate therapeutic approach by considering the possible genomic and epigenomic differences. MicroRNAs (miRNAs) comprise a class of small noncoding RNAs, which have remarkable functions in cell formation, differentiation, and cancer development and contribute in these processes through controlling the expressions of protein-coding genes by repressing translation or breaking down the messenger RNA in a sequence-specific method. miRNAs in cancer are able to reflect informative data about the current status of disease and this might benefit PCa prognosis and diagnosis since that is concerned to PCa patients and we intend to highlight it in this paper.     

Nanoformulation of curcumin protects HUVEC endothelial cells against ionizing radiation and suppresses their adhesion to monocytes: potential in prevention of radiation-induced atherosclerosis

Objectives

To investigated the potential of a novel dendrosomal nanoformulation of curcumin (DNC) in blocking radiation-induced changes in irradiated human umbilical vein endothelial cells (HUVECs), and their adhesion to human THP-1 monocytoid cells.

Results

Co⁶⁰ gamma rays reduced viability, raised the expression of adhesion molecules, ICAM-1, VCAM-1 and E-selectin (mRNA and protein), augmented the adhesion of THP-1 cells to HUVECs, activated NF-κB binding, increased the release of pro-inflammatory cytokines (IL-6, IL-8 and MCP-1) and induced oxidative damage (reduced glutathione declined, while 8-OHdG and TBARS increased). 5 µM DNC significantly inhibited these radiation-induced changes, activated the Nrf-2 pathway, and effectively suppressed THP-1 adhesion to HUVECs, implicating p38 MAPK signaling.

Conclusion

DNC treatment is a potential preventive method against inflammation and vascular damage from ionizing radiation.

     

Learning generative models of molecular dynamics

We introduce three algorithms for learning generative models of molecular structures from molecular dynamics simulations. The first algorithm learns a Bayesian-optimal undirected probabilistic model over user-specified covariates (e.g., fluctuations, distances, angles, etc). L1 regularization is used to ensure sparse models and thus reduce the risk of over-fitting the data. The topology of the resulting model reveals important couplings between different parts of the protein, thus aiding in the analysis of molecular motions. The generative nature of the model makes it well-suited to making predictions about the global effects of local structural changes (e.g., the binding of an allosteric regulator). Additionally, the model can be used to sample new conformations. The second algorithm learns a time-varying graphical model where the topology and parameters change smoothly along the trajectory, revealing the conformational sub-states. The last algorithm learns a Markov Chain over undirected graphical models which can be used to study and simulate kinetics. We demonstrate our algorithms on multiple molecular dynamics trajectories.     

Design,Synthesis and Molecular Docking Studies of Some Tetrahydropyrimidine Derivatives as Possible Fascin Inhibitors

Eight derivatives of tetrahydropyrimidine scaffold were designed and prepared as hybrid compounds possessing the structural features of both monastrol as an anticancer drug and nifedipine as a fascin blocking agent. All of the compounds were evaluated for their cytotoxic potency and the ability to inhibit 4T1 breast cancer cells migration. Then, they were investigated in silico for their ability to inhibit the fascin protein using molecular docking simulation. The most potent compound was 4d and the weakest one was 4a according to the in vitro cytotoxicity assay. The corresponding IC₅₀ values were 193.70 and 248.75 μm , respectively. The least cytotoxic compound ( 4a ) was one of the strongest ones in binding to the fascin binding site according to the molecular docking results. 4a and 4e inhibited the 4T1 cells migration better than other compounds. They were more potent than nifedipine in inhibiting the migration process. In silico studies proved 4h to be the most potent fascin inhibitor in terms of ΔG_bind although it was not inhibiting migration. The controversy between the in vitro and in silico results may cancel the theory of the involvement of the fascin inhibition in the migration inhibition. However, the considerable antimigratory effects of some of the synthesized compounds encourage performing further in vivo experiments to introduce novel tumor metastasis inhibitors.     

Improving purification of recombinant human interferon gamma expressed in Escherichia coli; effect of removal of impurity on the process yield

Process development and optimization studies were performed in order to improve the purification process of (rhIFN-gamma). The objective was to generate material with higher purity and quantity. An in-process control screening was developed to obtain the optimal condition for column chromatographic purification by measuring LPS, nucleic acids, rhIFN- gamma, monomer and its covalent dimers. A new resin screening method was applied to select optimal resin for each of the chromatographic columns. The resulting process used Butyl and Q-Sepharose, refolding and SP-Sepharose for purification of IFN-gamma. Effects of different process conditions such as cell lysis, removal of impurity and oxygen concentration were evaluated. Removal of impurities was evaluated by washing of inclusion bodies with 1% Triton X-100 and 3M urea and different chromatography steps. The results reveal that Triton removed about 43% of the LPS but urea had no effect on removal of nucleic acids and LPS. Further analysis show that removal of impurities by column chromatography decreases aggregation and increases the process yield. Oxygen concentration was identified as parameter that could have a significant impact on covalent dimers formation, as an unacceptable pharmaceutical form of rhIFN-gamma. On the basis of small-scale studies, optimum operating conditions were chosen and the purification process was successfully scaled-up to a pilot scale process with step yield and product quality that were better than previous reports.     

Relationship of stimulated whole saliva cortisol level with the severity of a feeling of dry mouth in menopausal women

doi: 10.1111/j.1741‐2358.2010.00403.x Relationship of stimulated whole saliva cortisol level with the severity of a feeling of dry mouth in menopausal women Objectives: To evaluate the relationship of stimulated whole saliva cortisol level with the severity of a feeling of dry mouth (DM) in menopausal women. Background: A feel of DM is a major complaint for many elderly individuals and strongly associated with the menopause. The exact mechanisms that mediate sensation of DM in menopausal women have not been firmly established. Methods: A case–control study was carried out on 104 selected menopausal women with/without a feeling of DM, conducted at the Clinic of Oral Medicine, Tehran University of Medical Sciences. Xerostomia Inventory (XI) score was used as an index of DM severity. Stimulated whole saliva cortisol concentration (stimulated by chewing standard‐sized paraffin for 60 s) was measured by ELISA. Statistical analysis by Student’s t‐test and Spearman correlation was used. Results: The mean cortisol concentration of saliva, but not saliva cortisol output, was significantly higher in the cases than in the controls. There was significant positive correlation between XI score and concentration (r = 0.357, p = 0.000) or output (r = 0.223, p = 0.017) of stimulated whole saliva cortisol. Conclusions: It appears that stimulated whole saliva cortisol is high in menopausal women with a feeling of DM.     

EEG Biofeedback for Treatment of Psychogenic Non-Epileptic Seizures (PNES) in Multiple Sclerosis: A Case Report

Applied Psychophysiology and Biofeedback - The objective of the present study was to evaluate the effectiveness of EEG biofeedback for treatment of psychogenic non-epileptic seizures (PNES) in a...