Putrescine Importer PlaP Contributes to Swarming Motility and Urothelial Cell Invasion in Proteus mirabilis

Previously, we reported that the speA gene, encoding arginine decarboxylase, is required for swarming in the urinary tract pathogen Proteus mirabilis. In addition, this previous study suggested that putrescine may act as a cell-to-cell signaling molecule (Sturgill, G., and Rather, P. N. (2004) Mol. Microbiol. 51, 437-446). In this new study, PlaP, a putative putrescine importer, was characterized in P. mirabilis. In a wild-type background, a plaP null mutation resulted in a modest swarming defect and slightly decreased levels of intracellular putrescine. In a P. mirabilis speA mutant with greatly reduced levels of intracellular putrescine, plaP was required for the putrescine-dependent rescue of swarming motility. When a speA/plaP double mutant was grown in the presence of extracellular putrescine, the intracellular levels of putrescine were greatly reduced compared with the speA mutant alone, indicating that PlaP functioned as the primary putrescine importer. In urothelial cell invasion assays, a speA mutant exhibited a 50% reduction in invasion when compared with wild type, and this defect could be restored by putrescine in a PlaP-dependent manner. The putrescine analog Triamide-44 partially inhibited the uptake of putrescine by PlaP and decreased both putrescine stimulated swarming and urothelial cell invasion in a speA mutant

Identification of a novel intronic enhancer responsible for the transcriptional regulation of musashi1 in neural stem/progenitor cells

<p>Abstract</p> <p>Background</p> <p>The specific genetic regulation of neural primordial cell determination is of great interest in stem cell biology. The Musashi1 (Msi1) protein, which belongs to an evolutionarily conserved family of RNA-binding proteins, is a marker for neural stem/progenitor cells (NS/PCs) in the embryonic and post-natal central nervous system (CNS). Msi1 regulates the translation of its downstream targets, including <it>m-Numb </it>and <it>p21 </it>mRNAs. <it>In vitro </it>experiments using knockout mice have shown that Msi1 and its isoform Musashi2 (Msi2) keep NS/PCs in an undifferentiated and proliferative state. Msi1 is expressed not only in NS/PCs, but also in other somatic stem cells and in tumours. Based on previous findings, Msi1 is likely to be a key regulator for maintaining the characteristics of self-renewing stem cells. However, the mechanisms regulating <it>Msi1 </it>expression are not yet clear.</p> <p>Results</p> <p>To identify the DNA region affecting <it>Msi1 </it>transcription, we inserted the fusion gene <it>ffLuc</it>, comprised of the fluorescent <it>Venus </it>protein and firefly <it>Luciferase</it>, at the translation initiation site of the mouse <it>Msi1 </it>gene locus contained in a 184-kb bacterial artificial chromosome (BAC). Fluorescence and Luciferase activity, reflecting the <it>Msi1 </it>transcriptional activity, were observed in a stable BAC-carrying embryonic stem cell line when it was induced toward neural lineage differentiation by retinoic acid treatment. When neuronal differentiation was induced in embryoid body (EB)-derived neurosphere cells, reporter signals were detected in Msi1-positive NSCs and GFAP-positive astrocytes, but not in MAP2-positive neurons. By introducing deletions into the BAC reporter gene and conducting further reporter experiments using a minimized enhancer region, we identified a region, "D5E2," that is responsible for <it>Msi1 </it>transcription in NS/PCs.</p> <p>Conclusions</p> <p>A regulatory element for <it>Msi1 </it>transcription in NS/PCs is located in the sixth intron of the <it>Msi1 </it>gene. The 595-bp D5E2 intronic enhancer can transactivate <it>Msi1 </it>gene expression with cell-type specificity markedly similar to the endogenous Msi1 expression patterns.</p

Tensile bond strength and SEM analysis of enamel etched with Er:YAG laser and phosphoric acid: a comparative study In vitro

Er:YAG laser has been studied as a potential tool for restorative dentistry due to its ability to selectively remove oral hard tissue with minimal or no thermal damage to the surrounding tissues. The purpose of this study was to evaluate in vitro the tensile bond strength (TBS) of an adhesive/composite resin system to human enamel surfaces treated with 37% phosphoric acid, Er:YAG laser (lambda=2.94 mum) with a total energy of 16 J (80 mJ/pulse, 2Hz, 200 pulses, 250 ms pulse width), and Er:YAG laser followed by phosphoric acid etching. Analysis of the treated surfaces was performed by scanning electron microscopy (SEM) to assess morphological differences among the groups. TBS means (in MPa) were as follows: Er:YAG laser + acid (11.7 MPa) > acid (8.2 MPa) > Er:YAG laser (6.1 MPa), with the group treated with laser+acid being significantly from the other groups (p=0.0006 and p= 0.00019, respectively). The groups treated with acid alone and laser alone were significantly different from each other (p=0.0003). The SEM analysis revealed morphological changes that corroborate the TBS results, suggesting that the differences in TBS means among the groups are related to the different etching patterns produced by each type of surface treatment. The findings of this study indicate that the association between Er:YAG laser and phosphoric acid can be used as a valuable resource to increase bond strength to laser-prepared enamel.A tecnologia a laser tem sido estudada como uma ferramenta potencial para uso em odontologia devido à sua habilidade em remover tecido ósseo com um mínimo ou nenhum dano aos tecidos vizinhos. O objetivo deste estudo é comparar in vitro a resistência à tração do sistema adesivo em esmalte tratado com ácido fosfórico a 37 %, laser Er:YAG (lambda=2,94 mim) com energia total de 16 J (80 mJ/pulso, 2 Hz, 200 pulsos e largura de pulso de 250 ms) e com a combinação laser Er:YAG seguido por ácido fosfórico. O teste de resistência à tração foi usado para comparar a resistência à tração em cada grupo. Foi também realizada microscopia eletrônica de varredura para permitir a análise das diferenças morfológicas entre os grupos. Foram obtidos os seguintes valores médios de resistência para os grupos tratados com: laser (6,1 MPa), ácido fosfórico (8,2 MPa) e laser mais ácido (11,7 Mpa). Amostras tratadas com laser e ácido apresentaram valores maiores de resistência do que amostras com laser ou ácido isoladamente. A análise da microscopia eletrônica revelou diferenças que corroboram os resultados, demonstrando que diferenças de resistência entre os grupos são devidas às diferenças entre os padrões superficiais resultantes. Nossos resultados sugerem que a combinação do laser Er:YAG com ácido fosfórico pode ser usada como um método para aumentar a resistência à tração do sistema esmalte resina

Depression and suicide risk prediction models using blood-derived multi-omics data

More than 300 million people worldwide experience depression; annually, ~800,000 people die by suicide. Unfortunately, conventional interview-based diagnosis is insufficient to accurately predict a psychiatric status. We developed machine learning models to predict depression and suicide risk using blood methylome and transcriptome data from 56 suicide attempters (SAs), 39 patients with major depressive disorder (MDD), and 87 healthy controls. Our random forest classifiers showed accuracies of 92.6% in distinguishing SAs from MDD patients, 87.3% in distinguishing MDD patients from controls, and 86.7% in distinguishing SAs from controls. We also developed regression models for predicting psychiatric scales with R2 values of 0.961 and 0.943 for Hamilton Rating Scale for Depression???17 and Scale for Suicide Ideation, respectively. Multi-omics data were used to construct psychiatric status prediction models for improved mental health treatment