International Journal of Molecular Sciences

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Open AccessArticle

Ordering of Polystyrene Nanoparticles on Substrates Pre-Coated with Different Polyelectrolyte Architectures

by Zuleyha Yenice, Matthias Karg and Regine Von Klitzing

Int. J. Mol. Sci. 2013, 14(6), 12893-12913; https://doi.org/10.3390/ijms140612893 - 20 Jun 2013

Cited by 3 | Viewed by 11336

Adjusting the inter-particle distances in ordered nanoparticle arrays can create new nano-devices and is of increasing importance to a number of applications such as nanoelectronics and optical devices. The assembly of negatively charged polystyrene (PS) nanoparticles (NPs) on Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes, quaternized [...] Read more.

Adjusting the inter-particle distances in ordered nanoparticle arrays can create new nano-devices and is of increasing importance to a number of applications such as nanoelectronics and optical devices. The assembly of negatively charged polystyrene (PS) nanoparticles (NPs) on Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes, quaternized PDMAEMA brushes and Si/PEI/(PSS/PAH)2, was studied using dip- and spin-coating techniques. By dip-coating, two dimensional (2-D), randomly distributed non-close packed particle arrays were assembled on Si/PEI/(PSS/PAH)2 and PDMAEMA brushes. The inter-particle repulsion leads to lateral mobility of the particles on these surfaces. The 200 nm diameter PS NPs tended to an inter-particle distance of 350 to 400 nm (center to center). On quaternized PDMAEMA brushes, the strong attractive interaction between the NPs and the brush dominated, leading to clustering of the particles on the brush surface. Particle deposition using spin-coating at low spin rates resulted in hexagonal close-packed multilayer structures on Si/PEI/(PSS/PAH)2. Close-packed assemblies with more pronounced defects are also observed on PDMAEMA brushes and QPDMAEMA brushes. In contrast, randomly distributed monolayer NP arrays were achieved at higher spin rates on all polyelectrolyte architectures. The area fraction of the particles decreased with increasing spin rate. Full article

(This article belongs to the Special Issue Self-Assembled Soft Matter Nanostructures at Interfaces)

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1338 KiB

Open AccessArticle

A Novel Perspective and Approach to Intestinal Octreotide Absorption: Sinomenine-Mediated Reversible Tight Junction Opening and Its Molecular Mechanism

by Yuling Li, Zhijun Duan, Yan Tian, Zhen Liu and Qiuming Wang

Int. J. Mol. Sci. 2013, 14(6), 12873-12892; https://doi.org/10.3390/ijms140612873 - 20 Jun 2013

Cited by 16 | Viewed by 7559

Abstract

In this work, we assessed the effects of sinomenine (SN) on intestinal octreotide (OCT) absorption both in Caco-2 cell monolayers and in rats. We also investigated the molecular mechanisms of tight junction (TJ) disruption and recovery by SN-mediated changes in the claudin-1 and [...] Read more.

In this work, we assessed the effects of sinomenine (SN) on intestinal octreotide (OCT) absorption both in Caco-2 cell monolayers and in rats. We also investigated the molecular mechanisms of tight junction (TJ) disruption and recovery by SN-mediated changes in the claudin-1 and protein kinase C (PKC) signaling pathway. The data showed that exposure to SN resulted in a signiﬁcant decrease in the expression of claudin-1, which represented TJ weakening and paracellular permeability enhancement. Then, the recovery of TJ after SN removal required an increase in claudin-1, which demonstrated the transient and reversible opening for TJ. Meanwhile, the SN-mediated translocation of PKC-α from the cytosol to the membrane was found to prove PKC activation. Finally, SN significantly improved the absolute OCT bioavailability in rats and the transport rate in Caco-2 cell monolayers. We conclude that SN has the ability to enhance intestinal OCT absorption and that these mechanisms are related at least in part to the important role of claudin-1 in SN-mediated, reversible TJ opening via PKC activation. Full article

(This article belongs to the Section Biochemistry)

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Open AccessArticle

Detection of Promyelocytic Leukemia/Retinoic Acid Receptor α (PML/RARα) Fusion Gene with Functionalized Graphene Oxide

by Ran Li, Yanhong Tan, Xiuhua Chen, Fanggang Ren, Yaofang Zhang, Zhifang Xu and Hongwei Wang

Int. J. Mol. Sci. 2013, 14(6), 12863-12872; https://doi.org/10.3390/ijms140612863 - 20 Jun 2013

Cited by 5 | Viewed by 6580

Abstract

An attempt was made to use functionalized graphene oxide (GO) to detect the Promyelocytic leukemia/Retinoic acid receptor α fusion gene (PML/RARα fusion gene), a marker gene of acute promyelocytic leukemia. The functionalized GO was prepared by chemical exfoliation method, followed by [...] Read more.

An attempt was made to use functionalized graphene oxide (GO) to detect the Promyelocytic leukemia/Retinoic acid receptor α fusion gene (PML/RARα fusion gene), a marker gene of acute promyelocytic leukemia. The functionalized GO was prepared by chemical exfoliation method, followed by a polyethylene glycol grafting. It is found that the functionalized GO can selectively adsorb the fluorescein isothiocyanate (FITC)-labeled single-stranded DNA probe and quench its fluorescence. The probe can be displaced by the PML/RARα fusion gene to restore the fluorescence, which can be detected by laser confocal microscopy and flow cytometry. These can be used to detect the presence of the PML/RARα fusion gene. This detection method is verified to be fast, simple and reliable. Full article

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Open AccessArticle

A Novel Low Temperature PCR Assured High-Fidelity DNA Amplification

by Guofan Hong, Sin Hang Lee, Shichao Ge and Shaoxia Zhou

Int. J. Mol. Sci. 2013, 14(6), 12853-12862; https://doi.org/10.3390/ijms140612853 - 20 Jun 2013

Cited by 6 | Viewed by 10073

Abstract

As previously reported, a novel low temperature (LoTemp) polymerase chain reaction (PCR) catalyzed by a moderately heat-resistant (MHR) DNA polymerase with a chemical-assisted denaturation temperature set at 85 °C instead of the conventional 94–96 °C can achieve high-fidelity DNA amplification of a target [...] Read more.

As previously reported, a novel low temperature (LoTemp) polymerase chain reaction (PCR) catalyzed by a moderately heat-resistant (MHR) DNA polymerase with a chemical-assisted denaturation temperature set at 85 °C instead of the conventional 94–96 °C can achieve high-fidelity DNA amplification of a target DNA, even after up to 120 PCR thermal cycles. Furthermore, such accurate amplification is not achievable with conventional PCR. Now, using a well-recognized L1 gene segment of the human papillomavirus (HPV) type 52 (HPV-52) as the template for experiments, we demonstrate that the LoTemp high-fidelity DNA amplification is attributed to an unusually high processivity and stability of the MHR DNA polymerase whose high fidelity in template-directed DNA synthesis is independent of non-existent 3'–5' exonuclease activity. Further studies and understanding of the characteristics of the LoTemp PCR technology may facilitate implementation of DNA sequencing-based diagnostics at the point of care in community hospital laboratories. Full article

(This article belongs to the Section Molecular Pathology, Diagnostics, and Therapeutics)

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Open AccessArticle

Reconstructing a Flavodoxin Oxidoreductase with Early Amino Acids

by Ming-Feng Lu, Hong-Fang Ji, Ting-Xuan Li, Shou-Kai Kang, Yue-Jie Zhang, Jue-Fei Zheng, Tian Tian, Xi-Shuai Jia, Xing-Ming Lin and Hong-Yu Zhang

Int. J. Mol. Sci. 2013, 14(6), 12843-12852; https://doi.org/10.3390/ijms140612843 - 19 Jun 2013

Cited by 5 | Viewed by 7671

Abstract

Primitive proteins are proposed to have utilized organic cofactors more frequently than transition metals in redox reactions. Thus, an experimental validation on whether a protein constituted solely by early amino acids and an organic cofactor can perform electron transfer activity is an urgent [...] Read more.

Primitive proteins are proposed to have utilized organic cofactors more frequently than transition metals in redox reactions. Thus, an experimental validation on whether a protein constituted solely by early amino acids and an organic cofactor can perform electron transfer activity is an urgent challenge. In this paper, by substituting “late amino acids (C, F, M, T, W, and Y)” with “early amino acids (A, L, and V)” in a flavodoxin, we constructed a flavodoxin mutant and evaluated its characteristic properties. The major results showed that: (1) The flavodoxin mutant has structural characteristics similar to wild-type protein; (2) Although the semiquinone and hydroquinone flavodoxin mutants possess lower stability than the corresponding form of wild-type flavodoxin, the redox potential of double electron reduction E_m,7 (fld) reached −360 mV, indicating that the flavodoxin mutant constituted solely by early amino acids can exert effective electron transfer activity. Full article

(This article belongs to the Section Biochemistry)

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Open AccessArticle

Overexpression of Arachis hypogaea AREB1 Gene Enhances Drought Tolerance by Modulating ROS Scavenging and Maintaining Endogenous ABA Content

by Xiao-Yun Li, Xu Liu, Yao Yao, Yi-Hao Li, Shuai Liu, Chao-Yong He, Jian-Mei Li, Ying-Ying Lin and Ling Li

Int. J. Mol. Sci. 2013, 14(6), 12827-12842; https://doi.org/10.3390/ijms140612827 - 19 Jun 2013

Cited by 67 | Viewed by 11244

Abstract

AhAREB1 (Arachis hypogaea Abscisic-acid Response Element Binding Protein 1) is a member of the basic domain leucine zipper (bZIP)-type transcription factor in peanut. Previously, we found that expression of AhAREB1 was specifically induced by abscisic acid (ABA), dehydration and drought. To [...] Read more.

AhAREB1 (Arachis hypogaea Abscisic-acid Response Element Binding Protein 1) is a member of the basic domain leucine zipper (bZIP)-type transcription factor in peanut. Previously, we found that expression of AhAREB1 was specifically induced by abscisic acid (ABA), dehydration and drought. To understand the drought defense mechanism regulated by AhAREB1, transgenic Arabidopsis overexpressing AhAREB1 was conducted in wild-type (WT), and a complementation experiment was employed to ABA non-sensitivity mutant abi5 (abscisic acid-insensitive 5). Constitutive expression of AhAREB1 confers water stress tolerance and is highly sensitive to exogenous ABA. Microarray and further real-time PCR analysis revealed that drought stress, reactive oxygen species (ROS) scavenging, ABA synthesis/metabolism-related genes and others were regulated in transgenic Arabidopsis overexpressing AhAREB1. Accordingly, low level of ROS, but higher ABA content was detected in the transgenic Arabidopsis plants’ overexpression of AhAREB1. Taken together, it was concluded that AhAREB1 modulates ROS accumulation and endogenous ABA level to improve drought tolerance in transgenic Arabidopsis. Full article

(This article belongs to the Section Biochemistry)

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Open AccessReview

Putative Genes Involved in Saikosaponin Biosynthesis in Bupleurum Species

by Tsai-Yun Lin, Chung-Yi Chiou and Shu-Jiau Chiou

Int. J. Mol. Sci. 2013, 14(6), 12806-12826; https://doi.org/10.3390/ijms140612806 - 19 Jun 2013

Cited by 33 | Viewed by 12051

Abstract

Alternative medicinal agents, such as the herb Bupleurum, are increasingly used in modern medicine to supplement synthetic drugs. First, we present a review of the currently known effects of triterpene saponins-saikosaponins of Bupleurum species. The putative biosynthetic pathway of saikosaponins in Bupleurum species [...] Read more.

Alternative medicinal agents, such as the herb Bupleurum, are increasingly used in modern medicine to supplement synthetic drugs. First, we present a review of the currently known effects of triterpene saponins-saikosaponins of Bupleurum species. The putative biosynthetic pathway of saikosaponins in Bupleurum species is summarized, followed by discussions on identification and characterization of genes involved in the biosynthesis of saikosaponins. The purpose is to provide a brief review of gene extraction, functional characterization of isolated genes and assessment of expression patterns of genes encoding enzymes in the process of saikosaponin production in Bupleurum species, mainly B. kaoi. We focus on the effects of MeJA on saikosaponin production, transcription patterns of genes involved in biosynthesis and on functional depiction. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism)

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Open AccessReview

Sesquiterpenoids Lactones: Benefits to Plants and People

by Martin Chadwick, Harriet Trewin, Frances Gawthrop and Carol Wagstaff

Int. J. Mol. Sci. 2013, 14(6), 12780-12805; https://doi.org/10.3390/ijms140612780 - 19 Jun 2013

Cited by 508 | Viewed by 34196

Abstract

Sesquiterpenoids, and specifically sesquiterpene lactones from Asteraceae, may play a highly significant role in human health, both as part of a balanced diet and as pharmaceutical agents, due to their potential for the treatment of cardiovascular disease and cancer. This review highlights the [...] Read more.

Sesquiterpenoids, and specifically sesquiterpene lactones from Asteraceae, may play a highly significant role in human health, both as part of a balanced diet and as pharmaceutical agents, due to their potential for the treatment of cardiovascular disease and cancer. This review highlights the role of sesquiterpene lactones endogenously in the plants that produce them, and explores mechanisms by which they interact in animal and human consumers of these plants. Several mechanisms are proposed for the reduction of inflammation and tumorigenesis at potentially achievable levels in humans. Plants can be classified by their specific array of produced sesquiterpene lactones, showing high levels of translational control. Studies of folk medicines implicate sesquiterpene lactones as the active ingredient in many treatments for other ailments such as diarrhea, burns, influenza, and neurodegradation. In addition to the anti-inflammatory response, sesquiterpene lactones have been found to sensitize tumor cells to conventional drug treatments. This review explores the varied ecological roles of sesquiterpenes in the plant producer, depending upon the plant and the compound. These include allelopathy with other plants, insects, and microbes, thereby causing behavioural or developmental modification to these secondary organisms to the benefit of the sesquiterpenoid producer. Some sesquiterpenoid lactones are antimicrobial, disrupting the cell wall of fungi and invasive bacteria, whereas others protect the plant from environmental stresses that would otherwise cause oxidative damage. Many of the compounds are effective due to their bitter flavor, which has obvious implications for human consumers. The implications of sesquiterpenoid lactone qualities for future crop production are discussed. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism)

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Open AccessArticle

Construction of the Coding Sequence of the Transcription Variant 2 of the Human Renalase Gene and Its Expression in the Prokaryotic System

by Valerii I. Fedchenko, Alexei A. Kaloshin, Lyudmila M. Mezhevikina, Olga A. Buneeva and Alexei E. Medvedev

Int. J. Mol. Sci. 2013, 14(6), 12764-12779; https://doi.org/10.3390/ijms140612764 - 19 Jun 2013

Cited by 23 | Viewed by 7808

Abstract

Renalase is a recently discovered protein, involved in regulation of blood pressure in humans and animals. Although several splice variants of human renalase mRNA transcripts have been recognized, only one protein product, hRenalase1, has been found so far. In this study, we have [...] Read more.

Renalase is a recently discovered protein, involved in regulation of blood pressure in humans and animals. Although several splice variants of human renalase mRNA transcripts have been recognized, only one protein product, hRenalase1, has been found so far. In this study, we have used polymerase chain reaction (PCR)-based amplification of individual exons of the renalase gene and their joining for construction of full-length hRenalase2 coding sequence followed by expression of hRenalase2 as a polyHis recombinant protein in Escherichia coli cells. To date this is the first report on synthesis and purification of hRenalase2. Applicability of this approach was verified by constructing hRenalase1 coding sequence, its sequencing and expression in E. coli cells. hRenalase1 was used for generation of polyclonal antiserum in sheep. Western blot analysis has shown that polyclonal anti-renalase1 antibodies effectively interact with the hRenalase2 protein. The latter suggests that some functions and expression patterns of hRenalase1 documented by antibody-based data may be attributed to the presence of hRenalase2. The realized approach may be also used for construction of coding sequences of various (especially weakly expressible) genes, their transcript variants, etc. Full article

(This article belongs to the Section Biochemistry)

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Open AccessReview

Role of CBFs as Integrators of Chloroplast Redox, Phytochrome and Plant Hormone Signaling during Cold Acclimation

by Leonid V. Kurepin, Keshav P. Dahal, Leonid V. Savitch, Jas Singh, Rainer Bode, Alexander G. Ivanov, Vaughan Hurry and Norman P. A. Hüner

Int. J. Mol. Sci. 2013, 14(6), 12729-12763; https://doi.org/10.3390/ijms140612729 - 18 Jun 2013

Cited by 122 | Viewed by 14838

Abstract

Cold acclimation of winter cereals and other winter hardy species is a prerequisite to increase subsequent freezing tolerance. Low temperatures upregulate the expression of C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB1) which in turn induce the expression of COLD-REGULATED (COR) genes. We [...] Read more.

Cold acclimation of winter cereals and other winter hardy species is a prerequisite to increase subsequent freezing tolerance. Low temperatures upregulate the expression of C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB1) which in turn induce the expression of COLD-REGULATED (COR) genes. We summarize evidence which indicates that the integration of these interactions is responsible for the dwarf phenotype and enhanced photosynthetic performance associated with cold-acclimated and CBF-overexpressing plants. Plants overexpressing CBFs but grown at warm temperatures mimic the cold-tolerant, dwarf, compact phenotype; increased photosynthetic performance; and biomass accumulation typically associated with cold-acclimated plants. In this review, we propose a model whereby the cold acclimation signal is perceived by plants through an integration of low temperature and changes in light intensity, as well as changes in light quality. Such integration leads to the activation of the CBF-regulon and subsequent upregulation of COR gene and GA 2-oxidase (GA2ox) expression which results in a dwarf phenotype coupled with increased freezing tolerance and enhanced photosynthetic performance. We conclude that, due to their photoautotrophic nature, plants do not rely on a single low temperature sensor, but integrate changes in light intensity, light quality, and membrane viscosity in order to establish the cold-acclimated state. CBFs appear to act as master regulators of these interconnecting sensing/signaling pathways. Full article

(This article belongs to the Section Biochemistry)

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Open AccessArticle

Dual Delivery of BMP-2 and bFGF from a New Nano-Composite Scaffold, Loaded with Vascular Stents for Large-Size Mandibular Defect Regeneration

by Jiansheng Su, Hongzhen Xu, Jun Sun, Xue Gong and Hang Zhao

Int. J. Mol. Sci. 2013, 14(6), 12714-12728; https://doi.org/10.3390/ijms140612714 - 18 Jun 2013

Cited by 76 | Viewed by 9793

Abstract

The aim of this study was to investigate the feasibility and advantages of the dual delivery of bone morphogenetic protein-2 (BMP-2) and basic fibroblast growth factor (bFGF) from nano-composite scaffolds (PLGA/PCL/nHA) loaded with vascular stents (PLCL/Col/nHA) for large bone defect regeneration in rabbit [...] Read more.

The aim of this study was to investigate the feasibility and advantages of the dual delivery of bone morphogenetic protein-2 (BMP-2) and basic fibroblast growth factor (bFGF) from nano-composite scaffolds (PLGA/PCL/nHA) loaded with vascular stents (PLCL/Col/nHA) for large bone defect regeneration in rabbit mandibles. Thirty-six large bone defects were repaired in rabbits using engineering bone composed of allogeneic bone marrow mesenchymal stem cells (BMSCs), bFGF, BMP-2 and scaffolds composed of PLGA/PCL/nHA loaded with PLCL/Col/nHA. The experiments were divided into six groups: BMSCs/bFGF/BMP-2/scaffold, BMSCs/BMP-2/scaffold, BMSCs/bFGF/scaffold, BMSCs/scaffold, scaffold alone and no treatment. Sodium alginate hydrogel was used as the carrier for BMP-2 and bFGF and its features, including gelling, degradation and controlled release properties, was detected by the determination of gelation and degradation time coupled with a controlled release study of bovine serum albumin (BSA). AlamarBlue assay and alkaline phosphatase (ALP) activity were used to evaluate the proliferation and osteogenic differentiation of BMSCs in different groups. X-ray and histological examinations of the samples were performed after 4 and 12 weeks post-implantation to clarify new bone formation in the mandible defects. The results verified that the use of sodium alginate hydrogel as a controlled release carrier has good sustained release ability, and the combined application of bFGF and BMP-2 could significantly promote the proliferation and osteogenic differentiation of BMSCs (p < 0.05 or p < 0.01). In addition, X-ray and histological examinations of the samples exhibited that the dual release group had significantly higher bone formation than the other groups. The above results indicate that the delivery of both growth factors could enhance new bone formation and vascularization compared with delivery of BMP-2 or bFGF alone, and may supply a promising way of repairing large bone defects in bone tissue engineering. Full article

(This article belongs to the Section Materials Science)

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Open AccessReview

Potential Mechanisms Linking Atherosclerosis and Increased Cardiovascular Risk in COPD: Focus On Sirtuins

by Graziamaria Corbi, Andrea Bianco, Viviana Turchiarelli, Michele Cellurale, Federica Fatica, Aurora Daniele, Gennaro Mazzarella and Nicola Ferrara

Int. J. Mol. Sci. 2013, 14(6), 12696-12713; https://doi.org/10.3390/ijms140612696 - 17 Jun 2013

Cited by 61 | Viewed by 10491

Abstract

The development of atherosclerosis is a multi-step process, at least in part controlled by the vascular endothelium function. Observations in humans and experimental models of atherosclerosis have identified monocyte recruitment as an early event in atherogenesis. Chronic inflammation is associated with ageing and [...] Read more.

The development of atherosclerosis is a multi-step process, at least in part controlled by the vascular endothelium function. Observations in humans and experimental models of atherosclerosis have identified monocyte recruitment as an early event in atherogenesis. Chronic inflammation is associated with ageing and its related diseases (e.g., atherosclerosis and chronic obstructive pulmonary disease). Recently it has been discovered that Sirtuins (NAD⁺-dependent deacetylases) represent a pivotal regulator of longevity and health. They appear to have a prominent role in vascular biology and regulate aspects of age-dependent atherosclerosis. Many studies demonstrate that SIRT1 exhibits anti-inflammatory properties in vitro (e.g., fatty acid-induced inflammation), in vivo (e.g., atherosclerosis, sustainment of normal immune function in knock-out mice) and in clinical studies (e.g., patients with chronic obstructive pulmonary disease). Because of a significant reduction of SIRT1 in rodent lungs exposed to cigarette smoke and in lungs of patients with chronic obstructive pulmonary disease (COPD), activation of SIRT1 may be a potential target for chronic obstructive pulmonary disease therapy. We review the inflammatory mechanisms involved in COPD-CVD coexistence and the potential role of SIRT1 in the regulation of these systems. Full article

(This article belongs to the Special Issue Oxidative Stress in Cardiovascular Disease)

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Open AccessArticle

Tracking the Interplay between Bound Peptide and the Lid Domain of DnaK, Using Molecular Dynamics

by Itzhaq Azoulay, Nataly Kucherenko, Esther Nachliel, Menachem Gutman, Abdussalam Azem and Yossi Tsfadia

Int. J. Mol. Sci. 2013, 14(6), 12675-12695; https://doi.org/10.3390/ijms140612675 - 17 Jun 2013

Cited by 4 | Viewed by 8033

Abstract

Hsp70 chaperones consist of two functional domains: the 44 kDa Nucleotide Binding Domain (NBD), that binds and hydrolyses ATP, and the 26 kDa Substrate Binding Domain (SBD), which binds unfolded proteins and reactivates them, utilizing energy obtained from nucleotide hydrolysis. The structure of [...] Read more.

Hsp70 chaperones consist of two functional domains: the 44 kDa Nucleotide Binding Domain (NBD), that binds and hydrolyses ATP, and the 26 kDa Substrate Binding Domain (SBD), which binds unfolded proteins and reactivates them, utilizing energy obtained from nucleotide hydrolysis. The structure of the SBD of the bacterial Hsp70, DnaK, consists of two sub-domains: A β-sandwich part containing the hydrophobic cavity to which the hepta-peptide NRLLLTG (NR) is bound, and a segment made of 5 α-helices, called the “lid” that caps the top of the β-sandwich domain. In the present study we used the Escherichia coli Hsp70, DnaK, as a model for Hsp70 proteins, focusing on its SBD domain, examining the changes in the lid conformation. We deliberately decoupled the NBD from the SBD, limiting the study to the structure of the SBD section, with an emphasis on the interaction between the charges of the peptide with the residues located in the lid. Molecular dynamics simulations of the complex revealed significant mobility within the lid structure; as the structure was released from the forces operating during the crystallization process, the two terminal helices established a contact with the positive charge at the tip of the peptide. This contact is manifested only in the presence of electrostatic attraction. The observed internal motions within the lid provide a molecular role for the function of this sub-domain during the reaction cycle of Hsp 70 chaperones. Full article

(This article belongs to the Special Issue Protein Folding)

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Open AccessArticle

Design, Synthesis, Biological Activity and Molecular Dynamics Studies of Specific Protein Tyrosine Phosphatase 1B Inhibitors over SHP-2

by Su-Xia Sun, Xiao-Bo Li, Wen-Bo Liu, Ying Ma, Run-Ling Wang, Xian-Chao Cheng, Shu-Qing Wang and Wei Liu

Int. J. Mol. Sci. 2013, 14(6), 12661-12674; https://doi.org/10.3390/ijms140612661 - 17 Jun 2013

Cited by 8 | Viewed by 10268

Abstract

Over expressing in PTPN1 (encoding Protein tyrosine phosphatase 1B, PTP1B), a protein tyrosine phosphatase (PTP) that plays an overall positive role in insulin signaling, is linked to the pathogenesis of diabetes and obesity. The relationship between PTP1B and human diseases exhibits PTP1B as [...] Read more.

Over expressing in PTPN1 (encoding Protein tyrosine phosphatase 1B, PTP1B), a protein tyrosine phosphatase (PTP) that plays an overall positive role in insulin signaling, is linked to the pathogenesis of diabetes and obesity. The relationship between PTP1B and human diseases exhibits PTP1B as the target to treat these diseases. In this article, small weight molecules of the imidazolidine series were screened from databases and optimized on silicon as the inhibitors of PTP1B based on the steric conformation and electronic configuration of thiazolidinedione (TZD) compounds. The top three candidates were tested using an in vitro biological assay after synthesis. Finally, we report a novel inhibitor, Compound 13, that specifically inhibits PTP1B over the closely related phosphatase Src homology 2 (SH2) domain-containing phosphatase 2 (SHP-2) at 80 μΜ. Its IC₅₀ values are reported in this paper as well. This compound was further verified by computer analysis for its ability to combine the catalytic domains of PTP1B and SHP-2 by molecular dynamics (MD) simulations. Full article

(This article belongs to the Collection Computational, Structural and Spectroscopic Studies of Enzyme Mechanisms, Inhibition and Dynamics)

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Open AccessArticle

Human Chorionic Gonadotropin Beta Subunit Genes CGB1 and CGB2 are Transcriptionally Active in Ovarian Cancer

by Marta Kubiczak, Grzegorz P. Walkowiak, Ewa Nowak-Markwitz and Anna Jankowska

Int. J. Mol. Sci. 2013, 14(6), 12650-12660; https://doi.org/10.3390/ijms140612650 - 17 Jun 2013

Cited by 11 | Viewed by 7755

Abstract

Human chorionic gonadotropin beta subunit (CGB) is a marker of pregnancy as well as trophoblastic and nontrophoblastic tumors. CGB is encoded by a cluster of six genes, of which type II genes (CGB3/9, 5 and 8) have been shown to [...] Read more.

Human chorionic gonadotropin beta subunit (CGB) is a marker of pregnancy as well as trophoblastic and nontrophoblastic tumors. CGB is encoded by a cluster of six genes, of which type II genes (CGB3/9, 5 and 8) have been shown to be upregulated in relation to type I genes (CGB6/7) in both placentas and tumors. Recent studies revealed that CGB1 and CGB2, originally considered as pseudogenes, might also be active, however, the protein products of these genes have not yet been identified. Our study demonstrates the presence of CGB1 and CGB2 transcripts in ovarian carcinomas. While CGB1 and CGB2 gene activation was not detected in normal ovaries lacking cancerous development, our study demonstrates the presence of CGB1 and CGB2 transcripts in 41% of analyzed ovarian cancer cases. Full article

(This article belongs to the Special Issue Genes and Pathways in the Pathogenesis of Ovarian Cancer)

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Open AccessReview

The Present and Future of Prostate Cancer Urine Biomarkers

by Marina Rigau, Mireia Olivan, Marta Garcia, Tamara Sequeiros, Melania Montes, Eva Colás, Marta Llauradó, Jacques Planas, Inés De Torres, Juan Morote, Colin Cooper, Jaume Reventós, Jeremy Clark and Andreas Doll

Int. J. Mol. Sci. 2013, 14(6), 12620-12649; https://doi.org/10.3390/ijms140612620 - 17 Jun 2013

Cited by 59 | Viewed by 13015

Abstract

In order to successfully cure patients with prostate cancer (PCa), it is important to detect the disease at an early stage. The existing clinical biomarkers for PCa are not ideal, since they cannot specifically differentiate between those patients who should be treated immediately [...] Read more.

In order to successfully cure patients with prostate cancer (PCa), it is important to detect the disease at an early stage. The existing clinical biomarkers for PCa are not ideal, since they cannot specifically differentiate between those patients who should be treated immediately and those who should avoid over-treatment. Current screening techniques lack specificity, and a decisive diagnosis of PCa is based on prostate biopsy. Although PCa screening is widely utilized nowadays, two thirds of the biopsies performed are still unnecessary. Thus the discovery of non-invasive PCa biomarkers remains urgent. In recent years, the utilization of urine has emerged as an attractive option for the non-invasive detection of PCa. Moreover, a great improvement in high-throughput “omic” techniques has presented considerable opportunities for the identification of new biomarkers. Herein, we will review the most significant urine biomarkers described in recent years, as well as some future prospects in that field. Full article

(This article belongs to the Special Issue Molecular Research in Urology)

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Open AccessReview

Quorum Sensing and Phytochemicals

by Filomena Nazzaro, Florinda Fratianni and Raffaele Coppola

Int. J. Mol. Sci. 2013, 14(6), 12607-12619; https://doi.org/10.3390/ijms140612607 - 17 Jun 2013

Cited by 203 | Viewed by 17647

Abstract

Most infectious diseases are caused by bacteria, which proliferate within quorum sensing (QS)-mediated biofilms. Efforts to block QS in bacteria and disrupt biofilms have enabled the identification of bioactive molecules that are also produced by plants. This mini review primarily focuses on natural [...] Read more.

Most infectious diseases are caused by bacteria, which proliferate within quorum sensing (QS)-mediated biofilms. Efforts to block QS in bacteria and disrupt biofilms have enabled the identification of bioactive molecules that are also produced by plants. This mini review primarily focuses on natural QS inhibitors, which display potential for treating bacterial infections and also enhance the safety of food supply. Full article

(This article belongs to the Special Issue Quorum Sensing Research in Microbial Systems)

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Open AccessArticle

Effect of Dietary Cholesterol and Cholesterol Oxides on Blood Cholesterol, Lipids, and the Development of Atherosclerosis in Rabbits

by Sun Jin Hur, Byungrok Min, Ki Chang Nam, Eun Joo Lee and Dong Uk Ahn

Int. J. Mol. Sci. 2013, 14(6), 12593-12606; https://doi.org/10.3390/ijms140612593 - 17 Jun 2013

Cited by 13 | Viewed by 7248

Abstract

Two studies were conducted to determine the effects of dietary cholesterol (CHO) and cholesterol oxides (COPs) on the development of atherosclerosis and the changes in fatty acid and blood characteristics in rabbits. In the first study, forty male New Zealand white rabbits were [...] Read more.

Two studies were conducted to determine the effects of dietary cholesterol (CHO) and cholesterol oxides (COPs) on the development of atherosclerosis and the changes in fatty acid and blood characteristics in rabbits. In the first study, forty male New Zealand white rabbits were divided into 5 groups and fed commercial rabbit chow with no added CHO or COPs, 1 g CHO, 0.9 g CHO + 0.1 g COPs, 0.8 g CHO + 0.2 g COPs, or 0.5 g CHO + 0.5 g COPs per kg diet. In the second study, 24 male New Zealand White rabbits were divided into 3 groups and fed a diet containing 2 g CHO, 1.6 g CHO + 0.4 g COPs, or 1.2 g CHO + 0.8 g COPs per kg diet. All diets induced atherosclerotic lesions in the rabbits’ ascending thoracic aorta. The serum CHO and triglyceride levels (p < 0.05) increased significantly with the increased levels of CHO in the diets. Dietary CHO or COPs did not influence high-density lipoprotein CHO levels. The ratio of saturated fatty acid to unsaturated fatty acid increased as the level of dietary CHO and COPs increased. Full article

(This article belongs to the Section Molecular Toxicology)

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Open AccessArticle

Anti-Inflammatory Components from the Root of Solanum erianthum

by Yu-Chang Chen, Hong-Zin Lee, Hsin-Chun Chen, Chi-Luan Wen, Yueh-Hsiung Kuo and Guei-Jane Wang

Int. J. Mol. Sci. 2013, 14(6), 12581-12592; https://doi.org/10.3390/ijms140612581 - 14 Jun 2013

Cited by 26 | Viewed by 8901

Abstract

Two new norsesquiterpenoids, solanerianones A and B (1–2), together with nine known compounds, including four sesquiterpenoids, (−)-solavetivone (3), (+)-anhydro-β-rotunol (4), solafuranone (5), lycifuranone A (6); one alkaloid, N-trans-feruloyltyramine [...] Read more.

Two new norsesquiterpenoids, solanerianones A and B (1–2), together with nine known compounds, including four sesquiterpenoids, (−)-solavetivone (3), (+)-anhydro-β-rotunol (4), solafuranone (5), lycifuranone A (6); one alkaloid, N-trans-feruloyltyramine (7); one fatty acid, palmitic acid (8); one phenylalkanoid, acetovanillone (9), and two steroids, β-sitosterol (10) and stigmasterol (11) were isolated from the n-hexane-soluble part of the roots of Solanum erianthum. Their structures were elucidated on the basis of physical and spectroscopic data analyses. The anti-inflammatory activity of these isolates was monitored by nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW264.7 cells. The cytotoxicity towards human lung squamous carcinoma (CH27), human hepatocellular carcinoma (Hep 3B), human oral squamous carcinoma (HSC-3) and human melanoma (M21) cell lines was also screened by using an MTT assay. Of the compounds tested, 3 exhibited the strongest NO inhibition with the average maximum inhibition (E_max) at 100 μM and median inhibitory concentration (IC₅₀) values of 98.23% ± 0.08% and 65.54 ± 0.18 μM, respectively. None of compounds (1–9) was found to possess cytotoxic activity against human cancer cell lines at concentrations up to 30 μM. Full article

(This article belongs to the Section Biochemistry)

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Open AccessArticle

Glycyrrhizin Represses Total Parenteral Nutrition-Associated Acute Liver Injury in Rats by Suppressing Endoplasmic Reticulum Stress

by Jai-Jen Tsai, Hsing-Chun Kuo, Kam-Fai Lee and Tung-Hu Tsai

Int. J. Mol. Sci. 2013, 14(6), 12563-12580; https://doi.org/10.3390/ijms140612563 - 14 Jun 2013

Cited by 24 | Viewed by 8754

Abstract

Total parenteral nutrition (TPN) is an artificial way to support daily nutritional requirements by bypassing the digestive system, but long-term TPN administration may cause severe liver dysfunction. Glycyrrhizin is an active component of licorice root that has been widely used to treat chronic [...] Read more.

Total parenteral nutrition (TPN) is an artificial way to support daily nutritional requirements by bypassing the digestive system, but long-term TPN administration may cause severe liver dysfunction. Glycyrrhizin is an active component of licorice root that has been widely used to treat chronic hepatitis. The aim of this study is to investigate the hepatoprotective effect of glycyrrhizin on TPN-associated acute liver injury in vivo. Liver dysfunction was induced by intravenous infusion of TPN at a flow rate of 20 mL/kg/h for three h in Sprague Dawley rats. The rats were pretreated with Glycyrrhizin (1, 3 and 10 mg/kg intravenously). After receiving TPN or saline (control group) for three h, the rats were sacrificed, blood samples were collected for biochemical analyses and liver tissue was removed for histopathological and immunohistochemical examination. We found that aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TB) and triglyceride (TG) levels were significantly increased in the TPN group without glycyrrhizin pretreatment and decreased in the glycyrrhizin-pretreated TPN group in a dose-dependent manner. The stained liver sections showed that glycyrrhizin relieved acute liver injury. The upregulation of serum protein biomarkers of reactive nitrogen species, including nitrotyrosine and inducible NO synthase (iNOS), were attenuated by glycyrrhizin pretreatment. Levels of endoplasmic reticulum (ER) stress factors, such as phosphorylation of JNK1/2, p38 MAPK and CHOP, were decreased by glycyrrhizin pretreatment. In summary, our results suggest that glycyrrhizin decreases TPN-associated acute liver injury factors by suppressing endoplasmic reticulum stress and reactive nitrogen stress. Full article

(This article belongs to the Section Biochemistry)

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Open AccessArticle

Does Melatonin Homeostasis Play a Role in Continuous Epigastric Pain Syndrome?

by Cezary Chojnacki, Tomasz Poplawski, Janusz Blasiak, Jan Chojnacki and Grazyna Klupinska

Int. J. Mol. Sci. 2013, 14(6), 12550-12562; https://doi.org/10.3390/ijms140612550 - 14 Jun 2013

Cited by 5 | Viewed by 8871

Abstract

Two clinical forms of functional dyspepsia (FD) are listed in the Rome III criteria: postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS), differing in the recurrence of ailments depending on the diet. Continuous EPS (CEPS) is observed in some EPS patients, also [...] Read more.

Two clinical forms of functional dyspepsia (FD) are listed in the Rome III criteria: postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS), differing in the recurrence of ailments depending on the diet. Continuous EPS (CEPS) is observed in some EPS patients, also at night, but its cause is still unknown. We showed previously that melatonin (MEL) homeostasis may be associated with FD. In the present work we evaluated selected components of melatonin homeostasis in patients with CEPS. The study included 30 patients with CEPS, 21 women and nine men, aged 21–49 years and 30 control subjects (EPS excluded); organic and mental diseases, as well as Helicobacter pylori infection, were excluded in both groups. The average severity of abdominal pain in the last three months was estimated in a 10-point scale (Visual Analog Scale). The levels of mRNA expression of arylalkylamine-N-acetyltransferase (AANAT) and hydroxyindole-O-methyltransferase (HIOMT), the main components of MEL homeostasis, were determined in gastric mucosa with real time PCR. The fasting serum level of MEL (at 09:00 a.m.) and circadian urine excretion of 6-sulfatoxymelatonin (6-HMS) were determined with ELISA. AANAT expression in antral mucosa of control subjects was 1.76 ± 0.41, in the gastric body 1.35 ± 0.38, and in the dyspeptic group 1.42 ± 0.38 (p < 0.05) and 0.92 ± 0.55 (p < 0.05), respectively. HIOMT expression in the control was 2.05 ± 0.70 in the antrum and 1.57 ± 0.69 in the body and in the CEPS group, it was: 1.51 ± 0.57 (p < 0.05) and 0.74 ± 0.31 (p < 0.001), respectively. MEL concentration (pg/mL) was 9.41 ± 3.09 in the control group and 5.62 ± 1.34 (p < 0.01) in the CEPS group. Urinary 6-HMS excretion (μg/24 h) was 11.40 ± 4.46 in the controls and 7.68 ± 2.88 (p < 0.05) in the CEPS. Moreover, a negative correlation was found between the tested parameters and severity of epigastric pain. These results indicate that patients with CEPS may display low level of AANAT and HIOMT expression in gastric mucosa, resulting in decreased MEL synthesis. Full article

(This article belongs to the Special Issue Advances in the Research of Melatonin)

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Open AccessArticle

Metabolomic-Based Study of the Leafy Gall, the Ecological Niche of the Phytopathogen Rhodococcus fascians, as a Potential Source of Bioactive Compounds

by Aminata P. Nacoulma, Olivier M. Vandeputte, Manuella De Lorenzi, Mondher El Jaziri and Pierre Duez

Int. J. Mol. Sci. 2013, 14(6), 12533-12549; https://doi.org/10.3390/ijms140612533 - 14 Jun 2013

Cited by 10 | Viewed by 10154

Abstract

Leafy gall is a plant hyperplasia induced upon Rhodococcus fascians infection. Previously, by genomic and transcriptomic analysis, it has been reported that, at the early stage of symptom development, both primary and secondary metabolisms are modified. The present study is based on the [...] Read more.

Leafy gall is a plant hyperplasia induced upon Rhodococcus fascians infection. Previously, by genomic and transcriptomic analysis, it has been reported that, at the early stage of symptom development, both primary and secondary metabolisms are modified. The present study is based on the hypothesis that fully developed leafy gall, could represent a potential source of new bioactive compounds. Therefore, non-targeted metabolomic analysis of aqueous and chloroform extracts of leafy gall and non-infected tobacco was carried out by ¹H-NMR coupled to principal component analysis (PCA) and orthogonal projections to latent structures-discriminant analysis (OPLS-DA). Polar metabolite profiling reflects modifications mainly in the primary metabolites and in some polyphenolics. In contrast, main modifications occurring in non-polar metabolites concern secondary metabolites, and gas chromatography and mass spectrometry (GC-MS) evidenced alterations in diterpenoids family. Analysis of crude extracts of leafy galls and non-infected tobacco leaves exhibited a distinct antiproliferative activity against all four tested human cancer cell lines. A bio-guided fractionation of chloroformic crude extract yield to semi-purified fractions, which inhibited proliferation of glioblastoma U373 cells with IC₅₀ between 14.0 and 2.4 µg/mL. Discussion is focused on the consequence of these metabolic changes, with respect to plant defense mechanisms following infection. Considering the promising role of diterpenoid family as bioactive compounds, leafy gall may rather be a propitious source for drug discovery. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism)

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Open AccessArticle

Activity of Laccase Immobilized on TiO₂-Montmorillonite Complexes

by Qingqing Wang, Lin Peng, Guohui Li, Ping Zhang, Dawei Li, Fenglin Huang and Qufu Wei

Int. J. Mol. Sci. 2013, 14(6), 12520-12532; https://doi.org/10.3390/ijms140612520 - 14 Jun 2013

Cited by 51 | Viewed by 10377

Abstract

The TiO₂-montmorillonite (TiO₂-MMT) complex was prepared by blending TiO₂ sol and MMT with certain ratio, and its properties as an enzyme immobilization support were investigated. The pristine MMT and TiO₂-MMT calcined at 800 °C (TiO₂ [...] Read more.

The TiO₂-montmorillonite (TiO₂-MMT) complex was prepared by blending TiO₂ sol and MMT with certain ratio, and its properties as an enzyme immobilization support were investigated. The pristine MMT and TiO₂-MMT calcined at 800 °C (TiO₂-MMT800) were used for comparison to better understand the immobilization mechanism. The structures of the pristine MMT, TiO₂-MMT, and TiO₂-MMT800 were examined by HR-TEM, XRD and BET. SEM was employed to study different morphologies before and after laccase immobilization. Activity and kinetic parameters of the immobilized laccase were also determined. It was found that the TiO₂ nanoparticles were successfully introduced into the MMT layer structure, and this intercalation enlarged the “d value” of two adjacent MMT layers and increased the surface area, while the calcination process led to a complete collapse of the MMT layers. SEM results showed that the clays were well coated with adsorbed enzymes. The study of laccase activity revealed that the optimum pH and temperature were pH = 3 and 60 °C, respectively. In addition, the storage stability for the immobilized laccase was satisfactory. The kinetic properties indicated that laccase immobilized on TiO₂-MMT complexes had a good affinity to the substrate. It has been proved that TiO₂-MMT complex is a good candidate for enzyme immobilization. Full article

(This article belongs to the Section Biochemistry)

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Open AccessArticle

Targeting Alternative Sites on the Androgen Receptor to Treat Castration-Resistant Prostate Cancer

by Nada Lallous, Kush Dalal, Artem Cherkasov and Paul S. Rennie

Int. J. Mol. Sci. 2013, 14(6), 12496-12519; https://doi.org/10.3390/ijms140612496 - 14 Jun 2013

Cited by 57 | Viewed by 14868

Abstract

Recurrent, metastatic prostate cancer continues to be a leading cause of cancer-death in men. The androgen receptor (AR) is a modular, ligand-inducible transcription factor that regulates the expression of genes that can drive the progression of this disease, and as a consequence, this [...] Read more.

Recurrent, metastatic prostate cancer continues to be a leading cause of cancer-death in men. The androgen receptor (AR) is a modular, ligand-inducible transcription factor that regulates the expression of genes that can drive the progression of this disease, and as a consequence, this receptor is a key therapeutic target for controlling prostate cancer. The current drugs designed to directly inhibit the AR are called anti-androgens, and all act by competing with androgens for binding to the androgen/ligand binding site. Unfortunately, with the inevitable progression of the cancer to castration resistance, many of these drugs become ineffective. However, there are numerous other regulatory sites on this protein that have not been exploited therapeutically. The regulation of AR activity involves a cascade of complex interactions with numerous chaperones, co-factors and co-regulatory proteins, leading ultimately to direct binding of AR dimers to specific DNA androgen response elements within the promoter and enhancers of androgen-regulated genes. As part of the family of nuclear receptors, the AR is organized into modular structural and functional domains with specialized roles in facilitating their inter-molecular interactions. These regions of the AR present attractive, yet largely unexploited, drug target sites for reducing or eliminating androgen signaling in prostate cancers. The design of small molecule inhibitors targeting these specific AR domains is only now being realized and is the culmination of decades of work, including crystallographic and biochemistry approaches to map the shape and accessibility of the AR surfaces and cavities. Here, we review the structure of the AR protein and describe recent advancements in inhibiting its activity with small molecules specifically designed to target areas distinct from the receptor’s androgen binding site. It is anticipated that these new classes of anti-AR drugs will provide an additional arsenal to treat castration-resistant prostate cancer. Full article

(This article belongs to the Special Issue Molecular Research in Urology)

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Open AccessArticle

Facile Synthesis of 5-Arylidene Thiohydantoin by Sequential Sulfonylation/Desulfination Reaction

by Jintao Han, Hongbo Dong, Zhihong Xu, Jianping Lei and Mingan Wang

Int. J. Mol. Sci. 2013, 14(6), 12484-12495; https://doi.org/10.3390/ijms140612484 - 13 Jun 2013

Cited by 19 | Viewed by 7840

Abstract

The sequential sulfonylation/desulfination reactions of 5-benzylthiohydantoin with excess arylsulfonyl chlorides in the presence of triethylamine have been developed to afford a wide range of 5-arylidene thiohydantoin derivatives in moderate to excellent yields. A plausible sulfonylation/desulfination mechanism was proposed. The bioassay showed that these [...] Read more.

The sequential sulfonylation/desulfination reactions of 5-benzylthiohydantoin with excess arylsulfonyl chlorides in the presence of triethylamine have been developed to afford a wide range of 5-arylidene thiohydantoin derivatives in moderate to excellent yields. A plausible sulfonylation/desulfination mechanism was proposed. The bioassay showed that these compounds exhibit certain fungicidal activities with the 71.9% inhibition rate of 2K against B. cinerea, and 57.6% inhibition rate of 2m against A. solani, respectively. Full article

(This article belongs to the Section Molecular Toxicology)

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Open AccessReview

The Melatonergic System in Mood and Anxiety Disorders and the Role of Agomelatine: Implications for Clinical Practice

by Domenico De Berardis, Stefano Marini, Michele Fornaro, Venkataramanujam Srinivasan, Felice Iasevoli, Carmine Tomasetti, Alessandro Valchera, Giampaolo Perna, Maria-Antonia Quera-Salva, Giovanni Martinotti and Massimo Di Giannantonio

Int. J. Mol. Sci. 2013, 14(6), 12458-12483; https://doi.org/10.3390/ijms140612458 - 13 Jun 2013

Cited by 68 | Viewed by 12458

Abstract

Melatonin exerts its actions through membrane MT1/MT2 melatonin receptors, which belong to the super family of G-protein-coupled receptors consisting of the typical seven transmembrane domains. MT1 and MT2 receptors are expressed in various tissues of the body either as single ones or together. [...] Read more.

Melatonin exerts its actions through membrane MT1/MT2 melatonin receptors, which belong to the super family of G-protein-coupled receptors consisting of the typical seven transmembrane domains. MT1 and MT2 receptors are expressed in various tissues of the body either as single ones or together. A growing literature suggests that the melatonergic system may be involved in the pathophysiology of mood and anxiety disorders. In fact, some core symptoms of depression show disturbance of the circadian rhythm in their clinical expression, such as diurnal mood and other symptomatic variation, or are closely linked to circadian system functioning, such as sleep-wake cycle alterations. In addition, alterations have been described in the circadian rhythms of several biological markers in depressed patients. Therefore, there is interest in developing antidepressants that have a chronobiotic effect (i.e., treatment of circadian rhythm disorders). As melatonin produces chronobiotic effects, efforts have been aimed at developing agomelatine, an antidepressant with melatonin agonist activity. The present paper reviews the role of the melatonergic system in the pathophysiology of mood and anxiety disorders and the clinical characteristics of agomelatine. Implications of agomelatine in “real world” clinical practice will be also discussed. Full article

(This article belongs to the Special Issue Advances in the Research of Melatonin)

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Open AccessReview

Protein Folding and Aggregation into Amyloid: The Interference by Natural Phenolic Compounds

by Massimo Stefani and Stefania Rigacci

Int. J. Mol. Sci. 2013, 14(6), 12411-12457; https://doi.org/10.3390/ijms140612411 - 13 Jun 2013

Cited by 179 | Viewed by 16976

Abstract

Amyloid aggregation is a hallmark of several degenerative diseases affecting the brain or peripheral tissues, whose intermediates (oligomers, protofibrils) and final mature fibrils display different toxicity. Consequently, compounds counteracting amyloid aggregation have been investigated for their ability (i) to stabilize toxic amyloid precursors; [...] Read more.

Amyloid aggregation is a hallmark of several degenerative diseases affecting the brain or peripheral tissues, whose intermediates (oligomers, protofibrils) and final mature fibrils display different toxicity. Consequently, compounds counteracting amyloid aggregation have been investigated for their ability (i) to stabilize toxic amyloid precursors; (ii) to prevent the growth of toxic oligomers or speed that of fibrils; (iii) to inhibit fibril growth and deposition; (iv) to disassemble preformed fibrils; and (v) to favor amyloid clearance. Natural phenols, a wide panel of plant molecules, are one of the most actively investigated categories of potential amyloid inhibitors. They are considered responsible for the beneficial effects of several traditional diets being present in green tea, extra virgin olive oil, red wine, spices, berries and aromatic herbs. Accordingly, it has been proposed that some natural phenols could be exploited to prevent and to treat amyloid diseases, and recent studies have provided significant information on their ability to inhibit peptide/protein aggregation in various ways and to stimulate cell defenses, leading to identify shared or specific mechanisms. In the first part of this review, we will overview the significance and mechanisms of amyloid aggregation and aggregate toxicity; then, we will summarize the recent achievements on protection against amyloid diseases by many natural phenols. Full article

(This article belongs to the Special Issue Protein Folding)

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Open AccessArticle

Immunomodulatory Activity of Recombinant Ricin Toxin Binding Subunit B (RTB)

by Wensen Liu, Na Xu, Hongyan Yuan, Songyan Li, Linna Liu, Zhaoyang Pu, Jiayu Wan, Huiwen Wang, Yaping Chang and Ruisheng Li

Int. J. Mol. Sci. 2013, 14(6), 12401-12410; https://doi.org/10.3390/ijms140612401 - 13 Jun 2013

Cited by 12 | Viewed by 7452

Abstract

Ricin toxin binding subunit B (RTB) is one of the subunits of the ricin protein. RTB has been used as adjuvant, but little is known about its mechanism. In this study, we found that RTB increased not only nitric oxide (NO) release, but [...] Read more.

Ricin toxin binding subunit B (RTB) is one of the subunits of the ricin protein. RTB has been used as adjuvant, but little is known about its mechanism. In this study, we found that RTB increased not only nitric oxide (NO) release, but also tumor necrosis factor (TNF)-α and interleukin (IL)-6 production in mouse macrophage cell line RAW264.7 cells. They subsequently exhibited enhanced ConA-induced T-cell and LPS-induced B-cell proliferative responses. We also examined the cytokines that were produced from splenocytes following in vitro RTB administration. Increased levels of IL-2, interferon (IFN)-γ and TNF-α were observed, while IL-4 and IL-5 were unaffected. These results demonstrate that recombinant RTB can act on the immune system and activate T-cells by introducing a Th1 immune response. Th1 cells might be the primary cellular target affected by RTB. Our results suggest that the recombinant RTB can promote the activation of macrophages and has a beneficial effect on immunomodulatory activity. Full article

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Open AccessArticle

Lymphocytes of Patients with Alzheimer’s Disease Display Different DNA Damage Repair Kinetics and Expression Profiles of DNA Repair and Stress Response Genes

by Giovana S. Leandro, Romulo R. Lobo, Douglas V. N. P. Oliveira, Julio C. Moriguti and Elza T. Sakamoto-Hojo

Int. J. Mol. Sci. 2013, 14(6), 12380-12400; https://doi.org/10.3390/ijms140612380 - 10 Jun 2013

Cited by 23 | Viewed by 8667

Abstract

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder, characterized by loss of memory and cognitive capacity. Given the limitations to analyze brain cells, it is important to study whether peripheral lymphocytes can provide biological markers for AD, an interesting approach, once they represent [...] Read more.

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder, characterized by loss of memory and cognitive capacity. Given the limitations to analyze brain cells, it is important to study whether peripheral lymphocytes can provide biological markers for AD, an interesting approach, once they represent the overall condition of the organism. To that extent, we sought to find whether lymphocytes of AD patients present DNA damage and repair kinetics different from those found in elderly matched controls (EC group) under in vitro treatment with hydrogen peroxide. We found that AD patient cells indeed showed an altered DNA repair kinetics (comet assay). Real-time quantitative analysis of genes associated with DNA stress response also showed that FANCG and CDKN1A are upregulated in AD, while MTH1 is downregulated, compared with the control group. In contrast, the expression of ATM, ATR and FEN1 genes does not seem to differ between these groups. Interestingly, TP53 protein expression was increased in AD patients. Therefore, we found that kinetics of the stress response in the DNA were significantly different in AD patients, supporting the hypothesis that repair pathways may be compromised in AD and that peripheral lymphocytes can reveal this condition. Full article

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Open AccessArticle

Expression and Role of GPR87 in Urothelial Carcinoma of the Bladder

by Homare Okazoe, Xia Zhang, Dage Liu, Shinsuke Shibuya, Nobufumi Ueda, Mikio Sugimoto and Yoshiyuki Kakehi

Int. J. Mol. Sci. 2013, 14(6), 12367-12379; https://doi.org/10.3390/ijms140612367 - 10 Jun 2013

Cited by 12 | Viewed by 8239

Abstract

The orphan GPR87 has recently been matched with its ligand LPA, which is a lipid mediator with multiple physiological functions, including cancer cell proliferation. This study aimed to clarify the role of GPR87 in urothelial carcinoma of the bladder. GPR87 expression was assessed [...] Read more.

The orphan GPR87 has recently been matched with its ligand LPA, which is a lipid mediator with multiple physiological functions, including cancer cell proliferation. This study aimed to clarify the role of GPR87 in urothelial carcinoma of the bladder. GPR87 expression was assessed in seven human bladder cancer cell lines. A replication-deficient recombinant adenoviral vector expressing shRNA targeting GPR87 (Ad-shGPR87), was constructed. Gene silencing was carried out using Ad-shGPR87. Immunohistochemical analysis was performed for transurethral resection of bladder tumor samples from 71 patients with non-muscle-invasive bladder cancer. We observed GPR87 expression in five of the seven cell lines, and silencing GPR87 gene expression significantly reduced cell viability. GPR87 expression was positive in 38 (54%) of 71 tumors. Ki-67 index was associated with positive GPR87 staining status (p < 0.0001). Patients with GPR87-positive tumors had shorter intravesical recurrence-free survival than those with GPR87-negative tumors (p = 0.010). Multivariate analysis revealed that GPR87 staining status was an independent prognostic parameter for intravesical recurrence (p = 0.041). Progression from non-muscle-invasive to muscle-invasive tumor was more frequently observed in patients with GPR87-positive tumors, although this trend did not reach statistical significance (p = 0.056). These results warrant further prospective studies to clarify the role of GPR87 expression in intravesical recurrence and progression in bladder cancer. Full article

(This article belongs to the Special Issue Molecular Research in Urology)

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Int. J. Mol. Sci., Volume 14, Issue 6 (June 2013) – 124 articles , Pages 10683-12913

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