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In the absence of copper, DsbS acts as a phosphatase toward DsbR, blocking the transcription of Dsb genes. In the presence of copper, the metal ion directly binds to the sensor domain of DsbS, and the Cys82 residue plays a critical role in this process. The copper-binding behavior appears to inhibit the phosphatase activity of DsbS, leading to the activation of DsbR and thus for copper resistance of Pseudomonas aeruginosa, an important human pathogen. [Display omitted] In nature, bacteria must sense copper and tightly regulate gene expression to evade copper toxicity. Here, we identify a new copper-responsive two-component system named DsbRS in the important human pathogen Pseudomonas aeruginosa ; in this system, DsbS is a sensor histidine kinase, and DsbR, its cognate response regulator, directly induces the transcription of genes involved in protein disulfide bond formation (Dsb) (i.e., the dsbDEG operon and dsbB). In the absence of copper, DsbS acts as a phosphatase toward DsbR, thus blocking the transcription of Dsb genes. In the presence of copper, the metal ion directly binds to the sensor domain of DsbS, and the Cys82 residue plays a critical role in this process. The copper-binding behavior appears to inhibit the phosphatase activity of DsbS, leading to the activation of DsbR. The copper resistance of the dsbRS knock-out mutant is restored by the ectopic expression of the dsbDEG operon, which is a DsbRS major target. Strikingly, cognates of the dsbRS - dsbDEG pair are widely distributed across eubacteria. In addition, a DsbR-binding site, which contains the consensus sequence 5′-TTA-N 8 -TTAA-3′, is detected in the promoter region of dsbDEG homologs in these species. These findings suggest that the regulation of Dsb genes by DsbRS represents a novel mechanism by which bacterial cells cope with copper stress. [ABSTRACT FROM AUTHOR]

Difenoconazole was believed to induce a large suite of symptoms during zebrafish development, but little is known about the negative invisible effect known as endocrine disruption. In this study, zebrafish ( Danio rerio ) embryos were exposed to various concentrations of difenoconazole from fertilization to 120 h post-fertilization (hpf), and the whole body content of thyroid hormone and gene transcription in the hypothalamic–pituitary–thyroid (HPT) axis were investigated. Results showed thyroxine (T4) levels were significantly decreased, while triiodothyronine (T3) concentrations were not changed. Moreover, the mRNA transcription of corticotrophin-releasing hormone ( crh ), thyroid-stimulating hormone ( tshβ ), transthyretin ( ttr ), thyronine deiodinase ( dio1 and dio2 ), uridine diphosphate glucuronosyltransferase ( ugt1ab ) in the HPT axis were significantly up-regulated, but the transcriptions of thyroglobulin ( tg ), sodium/iodide symporter ( nis ) and thyroid hormone receptors trβ were not changed. The overall results showed that exposure to difenoconazole could alter thyroid hormone levels and gene transcription in zebrafish larvae, indicating thyroid endocrine disruption. [ABSTRACT FROM AUTHOR]

With restricted usage of growth-promoting antibiotics, identifying alternative feed additives that both improve intestinal barrier function and reduce inflammation is the center to improve chickens' health. This study examined the effects of a microencapsulated feed additive containing citric acid, sorbic acids, thymol, and vanillin on intestinal barrier function and inflammation status. A total of 240 birds were assigned to either a commercial control diet or control diet supplemented with 500 g/MT of the microencapsulated additive product. Birds were raised by feeding a 2-phase diet (starter, d 1 to d 21; and grower, d 15 to d 42). Growth performance was recorded weekly. At d 21 and d 42, total gastrointestinal tract permeability was evaluated by FITC-dextran (FD4) oral gavage. Jejunum-specific barrier functions were evaluated by Ussing chamber. Intestinal gene expression of selected epithelial cell markers, tight junction (TJ) proteins, inflammatory cytokines, and endocannabinoid system (ECS) markers were determined by RT-PCR. Statistical analysis was performed using Student t test. Results showed significant improvement of feed efficiency in the birds supplemented with the blend of organic acids and botanicals. At d 21, both oral and jejunal FD4 permeability were lower in the supplemented group. Jejunal transepithelial resistance was higher in the supplemented birds. At d 21, expression of TJs mRNA (CLDN1 and ZO2) was both upregulated in the jejunum and ileum of supplemented birds, while CLDN2 was downregulated in cecum. Proliferating cell marker SOX9 was higher expressed in jejunum and ceca. Goblet cell marker (MUC2) was upregulated, while Paneth cell marker (LYZ) was downregulated in the ileum. Proinflammatory cytokine expressions of IL1B, TNFA , and IFNG were downregulated in jejunum, while anti-inflammatory IL10 expression was higher in jejunum, ileum, cecum, and cecal tonsil. The ECS markers expressions were upregulated in most intestinal regions. Together, these results demonstrated that the blend of organic acids and botanical supplementation reduced inflammation, improved the TJs expression and intestinal barrier function, and thus improved chicken feed efficiency. The activated ECS may play a role in reducing intestinal tissue inflammation. [ABSTRACT FROM AUTHOR]

Post-stroke depression (PSD) is a serious neuropsychiatric complication post stroke and leads to cognitive deficits. This study was conducted to explore the molecular mechanism of hypoxia-inducible factor-1α (HIF-1A) in cognitive dysfunction in rats with PSD. The rat model of PSD was established by middle cerebral artery occlusion, followed by 3 weeks of treatment with chronic unpredictable mild stress. The levels of miR-582–5p, HIF-1A, and neighbor of Brca1 gene (NBR1) in brain tissues were determined using RT-qPCR. The behaviors and cognitive capacity of rats were evaluated by various behavioral tests. PSD rats were injected with HIF-1A/miR-582–5p lowexpression vectors or NBR1 overexpression vectors via stereotactic method. The binding of HIF-1A to NBR1 or miR-582–5p was analyzed by chromatin immunoprecipitation and dual-luciferase assay. HIF-1A and NBR1 were highly expressed while miR-582–5p was poorly expressed in the brain of PSD rats. HIF-1A inhibition alleviated cognitive dysfunction of PSD rats. miR-582–5p was the upstream miRNA of HIF-1A, and HIF-1A specifically interacted with the NBR1 promoter to enhance NBR1 expression. miR-582–5p downregulation and NBR1 upregulation reversed the alleviative role of HIF-1A inhibition in cognitive dysfunction of PSD rats. In summary, HIF-1A inhibition may be a therapeutic target for cognitive dysfunction post PSD. [ABSTRACT FROM AUTHOR]

MicroRNA (miRNA) can regulate the expression of its target gene by mediating mRNA cleavage or by translational repression at a post-transcriptional level. Usually, one miRNA may regulate many genes as its targets, while one gene may also be targeted by many miRNAs. We previously demonstrated that cyb561d2 , whose protein product is involved in cell defense, and chemical stress, is targeted by miR-155 in adult zebrafish ( Danio rerio ) when exposed to fipronil (5-amino-1-[2,6-dichloro-4-(trifluoromethyl) phenyl]-4-[(trifluoromethyl) sulphinyl]-1H-pyrazole-3-carbonitrile). Microcosm Targets prediction showed that the cyb561d2 gene is also highly possibly targeted by miR-194a , miR-216b , miR-429 , and miR-499 . These interactions need to be further validated experimentally. In this study, we evaluated the effects of fipronil on miR-194a , miR-216b , miR-429 , miR-499 and cyb561d2 in zebrafish and investigated whether these four miRNAs c ould regulate the expression of cyb561d2 in both mRNA and protein levels. The expression of cyb561d2 was upregulated in both mRNA and protein level in a dose-dependent manner upon stimulation of fipronil, and miR-216b and miR-499 were downregulated concurrently, whereas there was no significant changes were observed in the expression level of miR-194a and miR-429 . The dual luciferase report assay demonstrated that miR-216 b and miR-499 interacted with cyb561d2 3′-untranslated regions (3′-UTR), miR-194a and miR-429 did not stimulate degradation of cyb561d2 mRNA. The expression of cyb561d2 was reduced in both mRNA and protein level when ZF4 cells were transfected with miR-499 mimic, whereas expression level of both mRNA and protein was increased when endogenous miR-499 was inhibited by transfection with miR-499 inhibitor. Likewise, the mRNA and protein level of cyb561d2 was affected by treatment with the mimics and the inhibitor of miR-216b . In contrast, when ZF4 cells were transfected with a mimic of miR-194a or miR-429 , the expression of cyb561d2 mRNA was not significantly changed. As a result, cyb561d2 is targeted by miR-155 , miR-216b and miR-499 upon fipronil exposure, and miR-194a and miR-429 can not target cyb561d2 . The expression pattern of these 3 miRNAs presents novel fipronil responses that could be used as a toxicological biomarker. [ABSTRACT FROM AUTHOR]

Abstract: Porcine circovirus type 2 (PCV2) infection has been suggested as an acquired immunodeficiency disorder. However, the immunopathogenesis of PCV2 infection is still not fully clarified. In the present study, 35 inguinal lymph nodes (LNs) with different levels of PCV2 load obtained from postwaening multisystemic wasting syndrome (PMWS)-affected pigs and 7 from healthy subclinically PCV2-infected pigs were selected. The LNs were subsequently ranked by their PCV2 loads to mimic the progression of PCV2 infection-associated lesion development. The expressions of 96 selected immune genes in these LNs were assessed by the integration of several reverse transcription quantitative real-time polymerase chain reaction experiments. Hierarchical cluster analysis of the gene expression profiles resulted in 5 major clusters (A, B, C, D, and E). Different clusters of immune gene expression profiles were compatible with the divergent functions of various immune cell subpopulations. 61 out of 96 selected genes belonged to cluster C and were mainly involved in the activation of dendritic cells and B and T lymphocytes. The expression levels of these genes were generally up-regulated in the LNs obtained from PMWS-affected pigs with relatively lower PCV2 loads. However, the up-regulated level tended to reduce or turned into down-regulation as the PCV2 load increased. Genes belonging to cluster B, involved in T cell receptor signaling, became silenced as the PCV2 load increased. The expression profiles of macrophage-associated genes were either independent from or positively correlated with the PCV2 load, such as those in clusters A and E and in cluster D, respectively. In addition, the principle component analysis of the expression of the 96 selected genes in the 42 inguinal LNs revealed that 53.10% and 72.29% of the total data variants could be explained by the top-3 and top-7 principle components, respectively, suggesting that the disease development of PCV2 infection may be associated with a few major and some minor factors. In conclusion, assessment of immune gene expression profiles in LNs supports a close interaction between immune activation and suppression during the progression of PMWS development. [Copyright &y& Elsevier]

Summary: We examined the role of macrophage inflammatory protein (MIP)-3α on oral cavity squamous cell carcinoma (OSCC) and whether it was involved in modulating OSCC cell functions. The study population was comprised of 102 patients with OSCC. MIP-3α levels in tissues were examined by immunohistochemistry and quantitative real-time RT-PCR. Effects of MIP-3α on OSCC cell function were investigated by cell proliferation assays, trans-well migration/invasion assays, and RNA interference. We found that MIP-3α was overexpressed in OSCC tumor cells. MIP-3α expression was significantly higher in tumor cells vs. normal epithelial cells, as determined by both quantitative real-time RT-PCR and immunohistochemistry. Overexpression of MIP-3α was significantly correlated with positive pN status (P =0.036). Nevertheless, there were no correlations related to patient age, pT status, overall pathological stage, cell differentiation, or perineural invasion. The long-term disease-specific survival for patient subgroups stratified by the absence or presence of MIP-3α overexpression was 70.9% vs. 54.7% (P =0.041). Multivariate analysis indicated that MIP-3α overexpression had a significantly lower disease-specific survival (hazard ratio: 2.158; P =0.037). Additionally, in vitro suppression of MIP-3α expression in OECM-1 cells using specific interfering RNAs attenuated cell migration and invasiveness. These findings suggest that MIP-3α overexpression in OSCC is associated with a poorer prognosis for patient survival and contributes to tumor metastasis. [ABSTRACT FROM AUTHOR]