Periostin potently promotes metastatic growth of colon cancer by augmenting cell survival via the Akt/PKB pathway

Molecular mechanisms associated with tumor metastasis remain poorly understood. Here we report that acquired expression of periostin by colon cancer cells greatly promoted metastatic development of colon tumors. Periostin is overexpressed in more than 80% of human colon cancers examined with highest expression in metastatic tumors. Periostin expression dramatically enhanced metastatic growth of colon cancer by both preventing stress-induced apoptosis in the cancer cells and augmenting endothelial cell survival to promote angiogenesis. At the molecular level, periostin activated the Akt/PKB signaling pathway through the alpha(v)beta(3) integrins to increase cellular survival. These data demonstrated that the survival-promoting function is crucial for periostin to promote tumor metastasis of colon cancer

Molecular Cloning and Characterization of a Brassica napus L. MAP Kinase Involved in Oligochitosan-Induced Defense Signaling

Oligochitosan is a potent plant defense elicitor. In this paper, a novel Brassica napus mitogen-activated protein kinase (MAPK) gene induced by oligochitosan was isolated by rapid amplification of cDNA ends technique and designated as BnOIPK (oligochitosan-induced protein kinase (OIPK)). BnOIPK, with high sequence similarity to previously reported plant MAPK genes, encodes a 373-amino acid protein and belongs to the B subgroup of plant MAPK. Bioinformatics analysis showed BnOIPK contains one phosphorylation motif (TEY) and a conserved common docking domain in its C-terminal extension. With a constitutive expression in seedling leaves, BnOIPK is further upregulated upon treatment with plant hormone jasmonic acid (JA), but did not markedly respond to salicylic acid and abscisic acid. Activation of BnOIPK transcripts induced by oligochitosan depending on nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) was identified by using NO, H(2)O(2), and their scavenger, respectively. Polyclonal antibody BOK was prepared by using a 69-kD GST-BnOIPK fusion protein which was produced from pGEX-4T-1 vector. Western-blot assays showed BnOIPK could be induced by oligochitosan and JA at a short time. All these results suggest that BnOIPK might be a key node of JA-mediated defense signaling and act on the downstream of NO and H(2)O(2)

An integrated strategy for packet dropout in internet-based control system

ISBN: 978-1-4244-3908-9International audiencePacket dropout is one of the key issues which degrade performances of Internet-based Control System(ICS). An integrated strategy composed of active part and passive part to solve this problem is proposed in this paper. In the active part, the priority of control packets in ICS can be improved through differentiated services which decrease probability of control packet dropout. While in the passive part, a data packet dropout compensator is established to reduce the negative influence of packet dropout. The sufficient conditions for stabilizing the new result model are derived in the form of linear matrix inequalities (LMI). At last, the solvability and effectiveness of the results is evaluated using NS2

Preparation of conductive and transparent dipeptide hydrogels for wearable biosensor

Conductive and transparent dipeptide hydrogels are desirable building blocks to prepare soft electronic devices and wearable biosensors due to their excellent biocompatibility, multi-functionality, and physiochemical properties similar to those of body tissues. However, the preparation of such hydrogels featuring high conductivity and transparency is a huge challenge because of the hydrophobic feature of conductive additives making the doping process difficult. To overcome this issue, hydrophilic conductive polydopamine (PDA)-doped polypyrrole (PPy) nanoparticles are introduced into the dipeptide hydrogel networks to form conductive nanofibrils in situ to achieve a good level of hydrophilic templating of the hydrogel networks. This technique creates a complete conductive network and allows visible light to pass through. The strategy proposed herein not only endows the dipeptide hydrogel with good conductivity and high transparency, but also provides a great potential application of conductive dipeptide hydrogels for body-adhered signal detection, as evidenced by the experimental data

Development and Evaluation of a Multitarget Real-Time Taqman Reverse Transcription-PCR Assay for Detection of the Severe Acute Respiratory Syndrome-Associated Coronavirus and Surveillance for an Apparently Related Coronavirus Found in Masked Palm Civets

Severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) is the etiological agent of SARS. It is believed that SARS-CoV originates from wild animals. We have developed a multitarget real-time Taqman reverse transcription-PCR (RT-PCR) assay for the quantitative detection of SARS-CoV. The sequences of the Taqman probes with a minor groove binder and the corresponding primers were based on the sequences of the N gene, open reading frame (ORF) 3, and ORF 8. The overall linear range of this assay was from at least 10(1) to 10(6) copies per reaction, and the detection limit could reach less than 10 copies per reaction. The quantification results for SARS-CoV from cell culture correlated well with those of the RT-PCR by using any two of the three sets of primer and probe used in this assay. However, the results of quantification of SARS-CoV obtained by using a few available throat swab specimens from SARS patients and the N gene as the target were almost 10 times higher than those obtained by using ORF 3 and ORF 8. Using this assay, we also detected an apparently SARS-CoV-related coronavirus in the throat swab specimens from masked palm civets in the west part of Hubei Province, People's Republic of China

Isolation and characterization of angiotensin I-converting enzyme inhibitory peptides derived from porcine hemoglobin

Animal blood is potentially an untapped source of drugs and value-added food production. More than 400 million pigs are slaughtered each year but porcine blood is usually discarded in China. This study describes the isolation and characterization of angiotensin I-converting enzyme (ACE) inhibitory peptides derived from porcine hemoglobin. The most active hydrolysate was obtained from the peptic digestion of porcine hemoglobin. After the purification of ACE-inhibitory peptides with Sephadex LH-20 gel chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC) on C-18 column, two active fractions were obtained. They were analyzed by matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOF/MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). They were LGFPTTKTYFPHF and VVYPWT, corresponding to the 34-46 fragment of the a chain and the 34-39 fragment of the a chain of porcine hemoglobin, with IC50 values of 4.92 and 6.02 wM, respectively. They were the first found from porcine hemoglobin; in particular, LGFPTTKTYFPHF was a novel ACE-inhibitory peptide. In addition, the purified ACE inhibitors both competitively inhibited ACE, and maintained inhibitory activity even after incubation with gastrointestinal proteases. This suggests that these peptides might have a potential antihypertensive effect. (c) 2006 Elsevier Inc. All rights reserved

Surface Self-Assembly of Dipeptides on Porous CaCO3 Particles Promoting Cell Internalization

The self-assembling behavior of peptides and derivatives is crucial in the natural process to construct various architectures and achieve specific functions. However, the surface or interfacial self assembly, in particular, on the surface of micro-or nanoparticles is even less systematically investigated. Here, uniform porous CaCO3 micro particles were prepared with different charged, hydrophobic and hydrophilic surfaces to assess the self-assembling behavior of dipeptides composed of various sequences. Experimental results indicate that dipeptides with a negative charge in an aqueous solution preferred to self-assemble on the hydrophobic and positively charged surface of CaCO3 particles, which can be ascribed to the electrostatic and hydrophobic interaction between dipeptides and CaCO3 particles. Meanwhile, the Log p (lipid-water partition coefficient) of dipeptides has a significant effect on the self-assembling behavior of dipeptides on the surface of porous CaCO3; dipeptides with high Log p preferred to self-assemble on the surface of CaCO3 particles, resulting in the improved cell internalization efficiency of particles with low cytotoxicity. After loading with a model drug (doxorubicin), the particles show obvious antitumor activity in animal experiments and can reduce Dox side effects effectively

Surface Self-Assembly of Dipeptides on Porous CaCO3 Particles Promoting Cell Internalization

The self-assembling behavior of peptides and derivatives is crucial in the natural process to construct various architectures and achieve specific functions. However, the surface or interfacial self assembly, in particular, on the surface of micro-or nanoparticles is even less systematically investigated. Here, uniform porous CaCO3 micro particles were prepared with different charged, hydrophobic and hydrophilic surfaces to assess the self-assembling behavior of dipeptides composed of various sequences. Experimental results indicate that dipeptides with a negative charge in an aqueous solution preferred to self-assemble on the hydrophobic and positively charged surface of CaCO3 particles, which can be ascribed to the electrostatic and hydrophobic interaction between dipeptides and CaCO3 particles. Meanwhile, the Log p (lipid-water partition coefficient) of dipeptides has a significant effect on the self-assembling behavior of dipeptides on the surface of porous CaCO3; dipeptides with high Log p preferred to self-assemble on the surface of CaCO3 particles, resulting in the improved cell internalization efficiency of particles with low cytotoxicity. After loading with a model drug (doxorubicin), the particles show obvious antitumor activity in animal experiments and can reduce Dox side effects effectively