Oxytocin down-regulates mesenteric afferent sensitivity via the enteric OTR/nNOS/NO/KATP pathway in rat

BACKGROUND

Oxytocin plays an analgesic role in modulation of nociception and pain. Most work to date has focused on the central mechanisms of oxytocin analgesia, but little is known about whether peripheral mechanisms are also involved.

METHODS

The mesenteric afferent discharge was recorded in vitro. The expressions of oxytocin receptor (OTR) and neuronal nitric oxide synthase (nNOS) in longitudinal muscle myenteric plexus (LMMP) was identified by immunofluorescence.

KEY RESULTS

Oxytocin per se had no effect on the jejunal mesenteric afferent discharge, however, it markedly attenuated the bradykinin- or distention-evoked increase of mesenteric afferent discharge, which was mimiced by the nitric oxide (NO) donor sodium nitroprusside (SNP). Pretreatment of either NOS inhibitor L-NAME or NPLA largely reduced the inhibitory effect of oxytocin on bradykinin-evoked mesenteric afferent discharge. Such effect, to a large extent, was also alleviated by N-and P-type voltage-dependent calcium channel antagonists or KATP blocker glibenclamide. In addition, immunofluorescence studies show strong colocalization of OTR with nNOS in LMMP of the rat jejunum.

CONCLUSIONS & INFERENCES

Oxytocin down-regulates the mesenteric afferent sensitivity through nNOS-NO-KATP pathway. Our findings may reveal a new peripheral mechanism for oxytocin analgesia.

A new target for the old regulator: H-NS suppress T6SS secretory protein EvpP, the major virulence factor in the fish pathogen Edwardsiella tarda

The evpP gene in fish pathogen Edwardsiella tarda, coding the T6SS secretory protein EvpP and carrying an evpA-evpO independent promoter region, was crucial for host cell invasion. The transcription of evpP was positively regulated by either the two-component system EsrA-EsrB or iron concentration, and its overexpression was known to enhance the invasion ability in our previous study. This work demonstrated that the H-NS protein, a pleiotropic regulator of gene expression, was a new transcriptional modulator of evpP gene. The results showed that in vivo the transcriptional level of evpP was downregulated by H-NS and in vitro this global regulator interacted directly with evpP promoter region. Moreover, DNase I footprinting experiments mapping the interaction regions of H-NS and evpP revealed that this global regulator bound to evpP promoter and neighbouring areas at multiple sites. We provided a new insight into evpP regulation network and demonstrated the repression of H-NS to the transcription of evpP gene.

SIGNIFICANCE AND IMPACT OF THE STUDY

Recently, the devastating fish disease edwardsiellosis caused by Edwardsiella tarda has been widely concerned. The xenogeneic silencing of the classic regulator H-NS to the T6SS secretory protein EvpP, which played an important role in the virulence of Edw. tarda, was firstly reported in this study. It raised a better understanding of the virulence regulation of EvpP and provided more information about the complex infection mechanism of this pathogen. Our findings would contribute to the development of live attenuated vaccines against edwardsiellosis thus reducing the economic losses caused by this bacterium.

Prevalence and characterization of Salmonella enterica in dried milk-related infant foods in Shaanxi, China

The aim of this study was to investigate the existence and characteristics of Salmonella enterica in dried milk-related infant foods. Twenty-four (3.4%) of 705 samples, including 5 (2.0%) of 246 powdered infant formula, 18 (4.0%) of 445 infant rice cereal, and 1 (7.1%) of 14 other infant foods, were positive for Salmonella. Fifteen serotypes were identified in 40 Salmonella isolates; Salmonella Duesseldorf (15.0%) and Salmonella Indiana (15.0%) were more frequently detected than other serotypes. Resistance to chloramphenicol (82.5%) was most common, followed by tetracycline (57.5%), ceftiofur (52.5%), kanamycin (52.5%), streptomycin (50.0%), gentamycin (45.0%), nalidixic acid (35.0%), ceftriaxone (32.5%), ciprofloxacin (25.0%), amikacin (20.0%), and cefoxitin (15.0%). Twenty-eight (70.0%) isolates were resistant to ≥ 8 antimicrobials, with 5 (12.5%) being resistant to 14 antimicrobials. Amino acid substitutions in gyrase A (GyrA) were most frequently detected as Ser83Arg/Asp87Glu and in p53-associated Parkin-like cytoplasmic protein (ParC), they were all Ser80Arg; the quinolone resistance gene qnrS (47.5%) was commonly detected as well as aminoglycoside acetyltransferase [aac(6')-Ib; 25.0%], qnrA (17.5%), and qnrB (15.0%) genes. Thirty distinct pulsed-field gel electrophoresis patterns were identified among 40 isolates; no identical pulsed-field gel electrophoresis pattern was detected among Salmonella isolates with the same serovar that was recovered in 2010 and 2012. Our results suggest that dried milk-related infant foods could be contaminated with Salmonella and highlight that the dangers to infant health should not be neglected.

Association between polymorphisms in ADAM33, CD14, and TLR4 with asthma in the Uygur population in China

We evaluated the associations between single nucleotide polymorphisms (SNPs) and haplotypes of the genes encoding a disintegrin and metalloproteinase 33 (ADAM33), cluster of differentiation 14 (CD14), and Toll-like receptor 4 (TLR4) and the susceptibility of developing specific adult phenotypes of bronchial asthma in a Chinese Uygur population. Five SNPs of ADAM33 (T1, T2, and V4), 3 SNPs of CD14 (-1359G/T, -1145G/A, and -159T/C), and 2 SNPs of TLR4 (-896A/G and -1196C/T) were genotyped in a Chinese Uygur sample of 126 adult asthmatic patients and 126 control subjects. Gene polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism analysis. The genotyping results were confirmed in a random subgroup of our samples using direct DNA sequencing. The allele frequencies of ADAM33 T1 (TC), T2 (AG), and V4 (GG) were significantly higher in patients than in controls (P<0.05). The genotypes T1 (TC+CC), T2 (AG+AA), and V4 (CG+GG) significantly increased the risk of asthma. After adjusting for confounding factors, these associations were stronger and remained significant. The T1 (TC) and V4 (GG) genotypes in the ADAM33 gene were associated with significantly decreased FEV1 levels in patients with asthma. The haplotype frequencies of Hap3 (CAC) and Hap4 (CAG) were significantly higher in patients than in controls (P<0.05). Our results suggest that polymorphisms T1, T2, and V4 in ADAM33 may contribute to the susceptibility to asthma. Specific haplotypes of ADAM33 may contribute to a higher susceptibility to asthma in the Chinese Uygur population.

Vibrational Excitations and Low Energy Electronic Structure of Epoxide-decorated Graphene

We report infrared studies of adsorbed atomic oxygen (epoxide functional groups) on graphene. Two different systems are used as a platform to explore these interactions, namely, epitaxial graphene/SiC(0001) functionalized with atomic oxygen (graphene epoxide, GE) and chemically reduced graphene oxide (RGO). In the case of the model GE system, IR reflectivity measurements show that epoxide groups distort the graphene π bands around the K-point, imparting a finite effective mass and contributing to a band gap. In the case of RGO, epoxide groups are found to be present following the reduction treatment by a combination of polarized IR reflectance and transmittance measurements. Similar to the GE system, a band gap in the RGO sample is observed as well.

A sensitive and specific nanoparticle-assisted PCR assay for rapid detection of porcine parvovirus

A novel nanoparticle-assisted polymerase chain reaction (nanoPCR) assay to detect porcine parvovirus (PPV) is described here. Primers for this assay were designed based on the conserved region of the nonstructural protein 1 (NS1) gene of PPV, which encodes one of the nonstructural proteins. The sensitivity of the PPV nanoPCR assay was measured by using diluted recombinant plasmids in which the PPV NS1 gene had been inserted. The detection limit was 5.6 × 10(1) copies μl(-1) for the PPV nanoPCR assay vs 5.6 × 10(3) copies μl(-1) for conventional PCR assay. The results showed that the sensitivity of PPV nanoPCR assay was 100 times higher than that of conventional PCR assay. The PPV nanoPCR assay produced 142-bp product as expected when amplifying PPV DNA, while produced nothing when amplifying the DNA or cDNA of the following viruses: swine encephalomyocarditis virus, classical swine fever virus, porcine pseudorabies virus, porcine reproductive and respiratory syndrome virus, porcine teschovirus and porcine circovirus type II. PPV was detected in 108 of 109 clinical swine samples from Heilongjiang, Jilin and Henan provinces using the nanoPCR assay, and the results were confirmed by sequencing.

SIGNIFICANCE AND IMPACT OF THE STUDY

Nanoparticle-assisted polymerase chain reaction (nanoPCR) assay is an improved PCR. NanoPCR is highly sensitive and specific because the nanofluids formed in the nanobuffer have high thermal conductivity, which reduces the time required to reach the target temperature. It is more sensitive than conventional PCR, and it could detect the cases earlier than conventional PCR. This report describes the first application of the highly efficient nanoPCR technology for the detection of porcine parvovirus (PPV). The PPV nanoPCR assay will be useful for the detection and study of PPV and will also be applicable to improve the detection of other viruses.

DNA double-strand break repair is activated in carotid artery restenosis

Carotid stenosis is a narrowing or constriction of the inner surface of the carotid artery, usually caused by atherosclerosis. In the past decades, carotid angioplasty and stenting (CAS) has been developed into a credible option for the patients with carotid stenosis. However, restenosis remains a severe and unsolved issue after CAS treatment. Currently, the molecular mechanisms involved in the restenosis are still largely unclear. In this study, we found that the double-strand DNA breaks (DSBs) were induced by oxidative stress in the human carotid artery with restenosis by examining the level of γH2AX in the artery tissues. We further analyzed the activation of DNA damage repair pathways in the carotid restenosis. Our results suggest that non-homologues end joining (NHEJ), but not homologous recombination (HR), is mainly activated in the artery tissues with restenosis. Our results may provide clues to develop a new therapeutic strategy for carotid artery restenosis following CAS treatment.

Multifunctional gold nanostar conjugates for tumor imaging and combined photothermal and chemo-therapy

Uniform gold nanostars (Au NS) were conjugated with cyclic RGD (cRGD) and near infrared (NIR) fluorescence probe (MPA) or anti-cancer drug (DOX) to obtain multi-functional nanoconstructs, Au-cRGD-MPA and Au-cRGD-DOX respectively. The NIR contrast agent Au-cRGD-MPA was shown to have low cytotoxicity. Using tumor cells and tumor bearing mice, these imaging nanoparticles demonstrated favorable tumor-targeting capability mediated by RGD peptide binding to its over-expressed receptor on the tumor cells. The multi-therapeutic analogue, Au-cRGD-DOX, integrates targeting tumor, chemotherapy and photo-thermotherapy into a single system. The synergistic effect of photo-thermal therapy and chemotherapy was demonstrated in different tumor cell lines and in vivo using S180 tumor-bearing mouse models. The viability of MDA-MB-231 cells was only 40 % after incubation with Au-cRGD-DOX and irradiation with NIR light. Both tail vein and intratumoral injections showed Au-cRGD-DOX treated mice exhibiting the slowest tumor increase. These results indicate that the multifunctional nanoconstruct is a promising combined therapeutic agent for tumor-targeting treatment, with the potential to enhance the anti-cancer treatment outcomes.

Multi-therapeutic effects of human adipose-derived mesenchymal stem cells on radiation-induced intestinal injury

Radiation-induced intestinal injuries (RIII) commonly occur in patients who suffer from pelvic or abdominal cancer. However, current management of these injuries is ineffective. Recently, mesenchymal stem cells (MSCs) have been extensively used in regenerative medicine and have achieved a high level of efficacy. In the present study, we hypothesised that human adipose-derived mesenchymal stem cells (hAd-MSCs) could be used as potential tools to heal RIII. We observed that adult Sprague-Dawley rats that received whole-abdominal irradiation benefitted from hAd-MSC injection. hAd-MSCs had RIII-healing effects, including anti-inflammation, neovascularisation and maintenance of epithelium homeostasis, as indicated by elevated serum IL-10, upregulation of vascular endothelial growth factor, basic fibroblast growth factor and epidermal growth factor in irradiated intestine, mobilisation of CD31-positive haematopoietic stem cells or haematopoietic progenitor cells, and the prolonged presence of Bmi1-positive cells within crypts. Consequently, after hAd-MSC treatment, irradiated rats survived longer than non-treated animals. These results suggest that hAd-MSCs have therapeutic potential for RIII management.

A novel allele, HLA-A*03:01:09, identified by sequence-based typing in a Chinese individual

We describe the identification of a novel allele HLA-A*03:01:09 in a Chinese individual.

Targeted cancer therapy with a 2-deoxyglucose-based adriamycin complex

Adriamycin (ADM) has been effective against many types of solid tumors in clinical applications. However, its use is limited because of systemic toxicities, primarily cardiotoxicity, and multidrug resistance. In this study, a new active receptor-mediated complex, ADM conjugated with 2-amino-2-deoxy-d-glucose and succinic acid (2DG-SUC-ADM), was designed to target tumor cells through glucose transporter 1 (GLUT1). MTT assay and confocal images showed that the complex had better inhibition rate to tumor cells and low toxicity to normal cells. Most importantly, the complex displayed a potential to reverse overcome multidrug resistance in cancer cells, with more complex transported into the nucleus of tumor cells. Our in vivo experiments also showed that this new complex could significantly decrease organ toxicity and enhance the antitumor efficacy compared with free ADM, indicating a promising drug of 2DG-SUC-ADM for targeted cancer therapy.

A novel HLA-B allele, B*07:55, identified by sequence-based typing

The novel allele differs from HLA-B*07:02:01 by a single nucleotide substitution at position 538 in exon 3.

Identification of a novel HLA-A allele, A*24:128 in a Chinese individual

The novel HLA-A*24:128 shows one nucleotide change from HLA-A*24:02:01:01 in exon 2 at position 155 from A to G.

In vivo targeted deep-tissue photodynamic therapy based on near-infrared light triggered upconversion nanoconstruct

Two major challenges of current photodynamic therapy (PDT) are the limited tissue penetration of excitation light and poor tumor-selectivity of the photosensitizer (PS). To address these issues, we developed a multifunctional nanoconstruct consisting of upconversion nanoparticles (UCNPs) that transform near-infrared (NIR) light to visible light and a photosensitizer zinc(II) phthalocyanine (ZnPc). Folate-modified amphiphilic chitosan (FASOC) was coated on the surface of UCNPs to anchor the ZnPc close to the UCNPs, thereby facilitating resonance energy transfer from UCNPs to ZnPc. Confocal microscopy and NIR small animal imaging demonstrated the enhanced tumor-selectivity of the nanoconstructs to cancer cells that overexpressed folate receptor. Reactive oxygen species (ROS) generation in cancer cells under a 1-cm tissue was higher upon excitation of UCNPs with the 980 nm light than that with 660 nm irradiation. In vivo PDT treatments for deep-seated tumors demonstrated that NIR light-triggered PDT based on the nanoconstructs possessed remarkable therapeutic efficacy with tumor inhibition ratio up to 50% compared with conventional visible light-activated PDT with a noticeable reduced tumor inhibition ratio of 18%. These results indicate that the multifunctional nanoconstruct is a promising PDT agent for deep-seated tumor treatment and demonstrate a new paradigm for enhancing PDT efficacy.

A novel HLA-B allele, B*13:18, identified by sequence-based typing

The B*13:18 allele differs from the most closely matching allele B*13:02:01 by one nucleotide substitution in exon 3, at position 539.

Bioinformatics analysis of two microarray gene-expression data sets to select lung adenocarcinoma marker genes

BACKGROUND

Lung adenocarcinoma (LAC) is the most frequent histologic type of lung cancer and rates of adenocarcinoma are increasing in most countries. Recently, several molecular markers have been identified to predict LAC. However, more prognostic makers and the underlying role of those makers are still imperative.

AIM

In this study, our objective was to identify a set of discriminating genes that can be used for characterization and prediction of response to LAC.

MATERIALS AND METHODS

Using the bioinformatics analysis method, we merged two LAC datasets-GSE2514 and GSE7670 to find novel target genes and pathways to explain the pathogenicity.

RESULTS

The results showed that EDNRB (endothelin receptor type B), ADRB2 (beta-adrenergic receptor), S1PR1 (sphingosine-1-phosphate receptor 1), P2RY14 (PsY purinoceptor 14), LEPR (leptin-receptor), GHR (growth hormone receptor), PPM1D (protein phosphatase-1D), and GADD45B (growth arrest and DNA-damage-inducible, beta) have high degrees in response to LAC. Additionally, EDNRB, ADRB2, S1PR1, P2RY14, LEPR, and GHR may be involved in LAC through Neuroactive ligand-receptor interaction, but PPM1D and GADD45B may be through p53 signaling pathway. Some of our prediction had been demonstrated by previous reports, such as ADRB2, S1PR1, GHR, PPM1D, and GADD45B. Therefore, we hope our study could lay a basis for further study of other target genes, such as EDNRB, P2RY14, and LEPR.

CONCLUSIONS

It is effective to identify potential molecular marker for LAC and predict their underlying functions by bioinformatics analysis and graph clustering method. However, further experiments are still indispensable to confirm our conclusion.

Folate-modified gold nanoclusters as near-infrared fluorescent probes for tumor imaging and therapy

Ultra-small gold nanoclusters (Au NCs) are highly promising materials for tumor imaging and therapy because of their low toxicity, intrinsic fluorescence, and the availability of multifunctional groups for covalent linkage of diverse bioactive molecules. Au NCs stabilized by bovine serum albumin (BSA) were prepared via an improved "green" synthetic routine. To ameliorate the selective affinity of Au NCs for high folate receptor (FR) expressing tumors, folic acid (FA) was immobilized on the surface of Au NCs. Subsequently, a near-infrared (NIR) fluorescent dye MPA was conjugated with Au-FA NCs for in vitro and in vivo fluorescence imaging. Similarly, Doxorubicin (DOX), a widely used clinical anticancer drug, was also conjugated to the folate-modified Au NCs to form a prodrug (Au-FA-DOX). Cellular and in vivo acute toxicity studies demonstrated the low toxicity of the Au-FA-MPA to normal cells and tissues. Additionally, in vitro and in vivo study of the dynamic behavior and targeting ability of Au-FA-MPA to different tumors validated the high selective affinity of Au-FA-MPA to FR positive tumors. With regard to the Au-FA-DOX, high anti-tumor activity was displayed by this pro-drug due to the FR mediated uptake. Herein, all of the results supported the potential of using ligand-modified Au NCs for tumor imaging and targeted therapy.

Multifunctional near-infrared-emitting nano-conjugates based on gold clusters for tumor imaging and therapy

Gold nanoclusters (NCs) were functionalized as a fluorescent probe and a pro-drug intended for tumor diagnosis and therapy. Firstly, Au NCs were conjugated with methionine (Met) and MPA, a near-infrared (NIR) fluorescent dye, giving a probe, Au-Met-MPA. The tumor targeting capability endowed by Met as well as low cytotoxicity of this contrast agent and its clinical potential for tumor targeting imaging were demonstrated in vitro and in vivo. Secondly, Doxorubicin (DOX), a widely used clinical anti-cancer drug, was immobilized on the methionine modified Au NCs to form a pro-drug, Au-Met-DOX. The enhanced tumor affinity and improved anti-tumor activity of this pro-drug were demonstrated. Results in this study suggest not only the prospect of non-toxic Au NCs modified with functional ligands for tumor-targeted imaging, but also confirm the promising future of Au NCs as a core for the design of pro-drug in the field of cancer therapy.

Cigarette smoking extract causes hypermethylation and inactivation of WWOX gene in T-24 human bladder cancer cells

Genomic, epigenetic and expression alterations of WW domain containing oxidoreductase (WWOX) have been implicated in multiple tumor types. The current study was designed to examine the expression of WWOX in tumor tissues of human bladder transitional cell carcinoma (BTCC) and the influence of cigarette smoke extract (CSE) on WWOX expression and methylation status in T-24 bladder cancer cells. WWOX protein expression was evaluated by immunohistochemistry staining in a series of tumor samples from 78 patients with BTCC and 26 normal bladder tissues. The expression level and methylation status of WWOX in CSE-treated cells were examined by using quantitative Real-Time RT-PCR and methylation specific PCR, respectively. The expression levels of DNA methyltransferases (DNMTs) 1, 3A and 3B were also detected. We found that WWOX expression was absent or reduced in 79.5% (62/78) of BTCC tissues, but only in 19.2% (5/26) of normal bladder tissues. Loss of WWOX expression was correlated with tumor grade (P=0.019) and cigarette smoking (P=0.031), but was not associated with age, gender, tumor size and tumor number. Hypermethylation of WWOX promoter and exon 1 was specifically induced by CSE with a kinetics concurrent to the suppression of WWOX mRNA in T-24 cells. Furthermore, CSE treatment induced a significant time-dependent increase in the level of DNMT1, but has no effects on DNMT3A and DNMT3B. Taken together, these novel findings suggest that hypermethylation of WWOX induced by cigarette smoking may represent one underlying mechanism for the loss expression of WWOX in bladder cancer.