Regulation of vascular smooth muscle cell proliferation by nuclear orphan receptor Nur77

Endothelium-derived nitric oxide (NO) is a cytoprotective molecule to prevent endothelial cells (ECs) from apoptosis. CREB-binding protein (CBP) is involved in the apoptotic pathway in several tumor cells, however, little is known whether CBP is associated with apoptosis in ECs and the apoptotic effect of CBP on ECs is regulated by NO. Therefore, the purpose of the present study was to investigate whether silencing CBP expression could affect the sensitivity of ECs toward apoptotic stimuli and determined the role of NO. In this study, we found that when CBP expression was silenced by RNA interference, ECs were more prone to apoptosis under serum deprivation, whereas the apoptosis was not significantly induced in the serum-containing condition. The increased apoptosis is paralleled by a reduction of NO, and the apoptosis was reversed by NO donors, suggesting an important role of NO. Furthermore, CBP silencing decreased NO production by downregulating the endothelial NO synthase (eNOS) expression in a dose-dependent manner. These results indicated that CBP silencing is associated with decreased eNOS expression and NO production, and therefore concomitantly increased the sensitivity of ECs toward apoptosis.     

Molecular characterization and association analysis of <Emphasis Type="Italic">FBXO40</Emphasis> with partial hematological indexes in pig

F-box proteins are quite significant ubiquitin-proteasome pathway regulators in eukaryotic cells. FBXO40, a member of this large family, alters its expression pattern in muscle atrophy. Here we isolated most of the verified porcine FBXO40 coding sequence (CDS) (2258 bp) and assigned it to the porcine chromosome 13q4.1-4.6 by using the INRA-Minnesota porcine radiation hybrid panel, and we also explored the tissue expression distributions, which is relatively high in longissimus dorsi muscle, heart, low in kidney, small intestine, brain, hypophysis, lymphonode, thymus, spleen, large intestine, ovary, stomach, and undetectable in testis, liver, uterus and thyroid gland. Inferring phylogenetic tree was constructed to study the evolutionary implications. Moreover, a HindII (HincII)-RFLP (A/C) polymorphism in 3′-untranslated region (3′-UTR) of porcine FBXO40 gene was demonstrated by sequencing and PCR-restriction fragment length polymorphism (PCR-RFLP) analysis. Statistical analysis result of this polymorphism showed that the allele A was predominant in all detected indigenous breeds, but C in western introduced commercial breeds. The SNP was further analyzed in our experimental pig population including Tongcheng, Landrace, Large White, and crossbreds of Large White × (Landrace × Tongcheng) and Landrace × (Large White × Tongcheng). The association analysis results indicated that the A/C base substitution was associate with some hematological indexes, the hemoglobin concentration (P < 0.0001), mean corpuscular volume hemoglobin concentration (P = 0.0002) and mean corpuscular volume (P = 0.0138).     

Population genetic analysis of 6 Y-STR loci in Chinese northwestern Qinchuan yellow cattle breed

Six Y-STR loci (UMN0929, UMN0108, UMN0920, INRA124, UMN2404 and UMN0103) were analyzed using 576 healthy and unrelated males and 10 females of the Qinchuan cattle population in Chinese Shaanxi Province. Allele frequency, gene diversity, the polymorphic information content, and the number of effective gene were calculated. All loci were in accordance with the Hardy–Weinberg equilibrium (P > 0.05). The population data were compared with published data of other cattle breeds, suggesting that Qinchuan cattle were originated primarily from Bos Taurus. Results are valuable for individual identification, paternity testing, and origin analysis of Qinchuan cattle breed.     

Comparison of the extent of genetic variation of Vallisneria natans and its sympatric congener V. spinulosa in lakes of the middle-lower reaches of the Yangtze River

Vallisneria natans and Vallisneria spinulosa are two morphologically very similar and sympatrically dominant submerged macrophytes in lakes of the middle-lower reaches of the Yangtze River. Genetic variation was compared based on a total of 196 individuals from six V. natans populations and 201 individuals from seven V. spinulosa populations. Using eight ISSR primers, a total of 139 and 129 DNA fragments were generated with 121 being polymorphic in V. natans and 99 in V. spinulosa. The two species maintained higher genetic variation both at the species and population levels in comparison with other aquatic macrophytes. A higher level of genetic diversity among populations was found in V. natans than in V. spinulosa: the percentage of polymorphic loci (PPL) in V. natans was 52-62% vs. 38-47% in V. spinulosa; gene diversity (H) was 0.21 in V. natans vs. 0.17 in V. spinulosa.Both an analysis of molecular variance (AMOVA) and F-estimation (F_ST) showed that most of the total genetic variation resided within populations of both species (AMOVA: 85% and 80%; F_ST: 0.132 and 0.202), indicating low genetic differentiation between populations. Principal coordinates analysis (PCA) indicated evident gene flow between populations of both species. The outcrossing reproductive mode and pervasive gene flow might have played important roles in maintaining high genetic diversity and in shaping low population differentiation of the two Vallisneria species, while the extent of clonal growth might account for the different levels of population divergence between them.     

CREB up-regulates long non-coding RNA,HULC expression through interaction with microRNA-372 in liver cancer

Long non-coding RNA (lncRNA), highly up-regulated in liver cancer (HULC) plays an important role in tumorigenesis. Depletion of HULC resulted in a significant deregulation of several genes involved in liver cancer. Although up-regulation of HULC expression in hepatocellular carcinoma has been reported, the molecular mechanisms remain unknown. In this study, we used in vivo and in vitro approaches to characterize cancer-dependent alterations in the chromatin organization and find a CREB binding site (encompassing from −67 to −53 nt) in the core promoter. Besides, we also provided evidence that PKA pathway may involved in up-regulation of HULC. Furthermore, we demonstrated HULC may act as an endogenous ‘sponge’, which down-regulates a series of microRNAs (miRNAs) activities, including miR-372. Inhibition of miR-372 leads to reducing translational repression of its target gene, PRKACB, which in turn induces phosphorylation of CREB. Over-expression of miR-372 decreases the association of CREB with the proximal promoter, followed by the dissociation of P300, resulting in a change of the histone ‘code’, such as in deacetylation and methylation. The study elucidates that fine tuning of HULC expression is part of an auto-regulatory loop in which it’s inhibitory to expression and activity of miR-372 allows lncRNA up-regulated expression in liver cancer.     

Reducing Pectobacterium virulence by expression of an N-acyl homoserine lactonase gene Plpp-aiiA in Lysobacter enzymogenes strain OH11

An N-acyl homoserine lactonase gene aiiA, transcribed by a strong and constitutive Escherichia coli promoter P_lpp (Accession No. EU723847), was transformed into Lysobacter enzymogenes strain OH11, creating strain OH11A. The N-acyl-homoserine lactone (AHL)-degradation assay showed that transformant OH11A acquired the ability to degrade AHL molecules produced by Agrobacterium tumefaciens, Pectobacterium carotovorum, Pseudomonas syringae pv. tomato strain DC3000 and Acidovorax avenae subsp. citrulli. Pathogenicity tests showed that while the parental strain OH11 did not reduce P. carotovorum infection, the transformant OH11A caused a strong reduction of Pectobacterium virulence on Chinese cabbage and cactus, whereas strain OH11A did not seem to interfere with the normal growth of this pathogen in cabbages. In antimicrobial activity assays, strain OH11A and OH11 showed similar antimicrobial activity against Phytophthora capsici and Sclerotinia sclerotiorum. This work provided a new strategy for developing genetically engineered multi-functional L. enzymogenes strains that possessed the ability to biologically control fungal pathogens and reduce bacterial pathogenicity.     

An indirect ELISA for serodiagnosis of cattle footrot caused by Fusobacterium necrophorum

A serodiagnostic ELISA (rL-ELISA) using recombinant truncated leukotoxin protein PL2 (aa 311–644) of Fusobacterium necrophorum as antigen was developed for detection of antibodies against F. necrophorum from cattle footrot. In rL-ELISA, the recombinant diagnostic antigen showed no cross-reaction with antisera against bovine foot and mouth disease virus, bovine rhinotracheitis virus, bovine viral diarrhea virus, bovine rotavirus type A, bovine Escherichia coli, and bovine Salmonella. The rL-ELISA could confirm the existence of antibodies against F. necrophorum at day 7 after infection. Detection of the field samples indicated relative sensitivity of rL-ELISA to nL-ELISA using the purified native leukotoxin A as antigen was 96.43%, and relative specificity of rL-ELISA to nL-ELISA was 94.26%. These data demonstrated the rL-ELISA would have a potential use for early diagnosis of cattle footrot caused by F. necrophorum.     

Interactions Between Rhinanthus minor and Its Hosts: A Review of Water, Mineral Nutrient and Hormone Flows and Exchanges in the Hemiparasitic Association

At the ecological level, the effects of the facultative root hemiparasite Rhinanthus minor on the structure and functioning of its host communities are relative well described; yet until recently, the mechanistic basis for parasitic plant-driven community change and the physiological basis for the host-parasite interaction were poorly understood. Empirical incremental flow models, based on the increase in water, mineral nutrients, carbon assimilates or phytohormones between two defined time points, have been successfully employed to investigate the physiology of resource acquisition by- and distribution within host-parasitic plant associations. In this study we review the application of these empirical flow models to Rhinanthus-host associations showing the extent of and physiological basis of resource abstraction from the host and how this is profoundly influenced by soil nutrient status. We show that Rhinanthus primarily abstracts water and mineral nutrients via the apoplastic pathway through direct lumen-lumen connections with little resource acquisition via symplastic pathways. Nutrient status of the soil is shown to significantly influence the resource acquisition. We also investigate the hormonal regulation of resource acquisition by Rhinanthus showing pivotal roles for the key for the phytohormones abscisic acid (ABA) and cytokinins.     

Identification of NBS-Type Resistance Gene Homologs in Tobacco Genome

Tobacco (Nicotiana tabacum) is an important cash crop and an ideal experimental system for studies on plant–pathogen interaction. The sequenced tobacco genome provides an opportunity for examining resistance gene homologs (RGHs) in the tobacco genome. Thirty nucleotide-binding site-type RGHs were annotated from genomic data, and another 281 putative RGHs were identified via PCR amplification from wild and cultivated tobacco. The newly identified RGHs are similar to other known RGHs, and some were categorized into new groups or branches that are different from known Nicotiana R genes or RGHs. Of the 281RGHs, 146 were identified from a single tobacco genome. We did not find any polymorphism at the RGHs in cultivated accessions, implying that strong domestication selection and/or demographic effects might have caused a sharp reduction in nucleotide diversity. Three positive selection sites were found in several RGH groups, while purifying selection is pervasive in the RGH family. Our results provide a primary RGH pool and several positively selected sites for the further functional validation of resistance genes in tobacco.     

Carnosine protects against permanent cerebral ischemia in histidine decarboxylase knockout mice by reducing glutamate excitotoxicity

Recently, we showed that carnosine protects against NMDA-induced excitotoxicity in differentiated PC12 cells through a histaminergic pathway. However, whether the protective effect of the carnosine metabolic pathway also occurs in ischemic brain is unknown. Utilizing the model of permanent middle cerebral artery occlusion (pMCAO) in mice, we found that carnosine significantly improved neurological function and decreased infarct size in both histidine decarboxylase knockout and the corresponding wild-type mice to the same extent. Carnosine decreased the glutamate levels and preserved the expression of glutamate transporter-1 (GLT-1) but not the glutamate/aspartate transporter in astrocytes exposed to ischemia in vivo and in vitro. It suppressed the dissipation of ΔΨ_m and generation of mitochondrial reactive oxygen species (ROS) induced by oxygen–glucose deprivation in astrocytes. Furthermore, carnosine also decreased the mitochondrial ROS and reversed the decrease in GLT-1 induced by rotenone. These findings are the first to demonstrate that the mechanism of carnosine action in pMCAO may not be mediated by the histaminergic pathway, but by reducing glutamate excitotoxicity through the effective regulation of the expression of GLT-1 in astrocytes due to improved mitochondrial function. Thus, our study reveals a novel antiexcitotoxic agent in ischemic injury.