Actibacterium atlanticum sp. nov., isolated from surface seawater of the Atlantic Ocean

A taxonomic study was carried out on strain 22II-S11-z10^T, which was isolated from the surface seawater of the Atlantic Ocean. The bacterium was found to be Gram-stain negative, oxidase and catalase positive, oval- to rod-shaped and non-motile. Growth was observed at salinities of 0.5–9 % and at temperatures of 10–41 °C. The isolate can reduce nitrate to nitrite, degrade gelatin and aesculin, but can not degrade Tween 80. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22II-S11-z10^T belongs to the genus Actibacterium, with the highest sequence similarity to the type strain Actibacterium mucosum CECT 7668^T (97.3 %). The DNA–DNA hybridization estimate value between strain 22II-S11-z10^T and A. mucosum CECT 7668^T was 19.30 ± 2.29 %. The principal fatty acids were identified as Summed Feature 8 (C_18:1 ω7c/ω6c as defined by the MIDI system, 75.2 %) and Summed Feature 3 (C_16:1 ω7c/ω6c, 6.9 %). The G+C content of the chromosomal DNA was determined to be 59.0 mol%. The respiratory quinone was determined to be Q-10 (100 %). Phosphatidylglycerol, phosphatidylcholine, two phospholipids, two aminolipids and two lipids were identified in the polar lipids. The combined genotypic and phenotypic data show that strain 22II-S11-z10^T represents a novel species within the genus Actibacterium, for which the name Actibacterium atlanticum sp. nov. is proposed, with the type strain 22II-S11-z10^T (=MCCC 1A09298^T = LMG 27158^T).     

Rock2 promotes the invasion and metastasis of hepatocellular carcinoma by modifying MMP2 ubiquitination and degradation

Rho-associated coiled-coil-containing protein kinase 2 (Rock2) is a downstream effector of Rho that plays an important role in the tumorigenesis and progression of hepatocellular carcinoma (HCC). Matrix metalloproteinase 2 (MMP2) is a master regulator of tumor metastasis. In this study, we investigated the collections of Rock2 and MMP2 in HCCs and determined the potential role and molecular mechanism of Rock2 in MMP2-mediated invasiveness and metastasis. We found that Rock2 and MMP2 were markedly overexpressed in HCCs compared with the corresponding adjacent tissues, where a positive correlation in their expression was found. The knockdown of Rock2 significantly decreased MMP2 expression and inhibited the invasion and metastasis of HCC in vitro and in vivo. Additionally, the upregulation of MMP2 rescued the decreased migration and invasion induced by the knockdown of Rock2, whereas the knockdown of MMP2 decreased Rock2-enhanced HCC migration and invasion. Mechanistically, Rock2 stabilized MMP2 by preventing its ubiquitination and degradation. Together, our results link two drivers of invasion and metastasis in HCC and identify a novel pathway for MMP2 control.     

Growth variation in Abies georgei var. smithii along altitudinal gradients in the Sygera Mountains, southeastern Tibetan Plateau

A network of nine Smith fir (Abies georgei var. smithii) ring-width chronologies was constructed from sites ranging in elevation from 3,550 to 4,390 m above sea level (a.s.l.) in the Sygera Mountains, southeastern Tibetan Plateau. High-elevation trees had lower growth rates than did low-elevation trees. The mean tree-ring series intercorrelation (RBAR) increased with elevation. Principal component analysis identified three elevation zones (around 3,600, 3,800, and >4,200 m a.s.l.) with distinctive tree-ring growth patterns. Five chronologies with elevation >4,200 m a.s.l. were highly correlated. Overall, the initiation of tree-ring growth in Smith fir is controlled by common climatic signals, such as July minimum temperature, across a broad altitudinal range. Precipitation was not a growth-limiting factor across stands. Regardless of differences in stand elevation, topographical aspect, and tree age, the radial growth of Smith fir trees was markedly similar in response to common climatic signals, perhaps as a result of the relatively high-elevation of these forests (above 3,550 m a.s.l.) and the abundant summer monsoon rainfall. In addition, radial tree growth along the altitudinal gradients was indicative of a recent warming trend on the southeastern Tibetan Plateau.     

A cold-active β-glucosidase (Bgl1C) from a sea bacteria <Emphasis Type="Italic">Exiguobacterium oxidotolerans</Emphasis> A011

By constructing a genomic library, a new gene encoding β-glucosidase (Bgl1C) was cloned from Exiguobacterium oxidotolerans A011, which was isolated from deep sea mud. The putative β-glucosidase gene consisted of an open reading frame (ORF) of 1,347 nucleotides, and encoded a protein of 448 amino acids with a predicted molecular weight of 51.6 kDa. Bgl1C belonged to the glycoside hydrolase family 1, and the deduced amino acid sequence displayed the highest identity (68%) to the β-glucosidase from Bacillus coahuilensis m4-4. Optimal conditions for activity were pH 7 and a temperature of 35°C and Bgl1C was stable in buffers ranging from pH 6.6 to 9. The specific activity, K _m, and V _max for the substrate p-nitrophenyl-β-d-glucopyranoside were 41 U mg⁻¹, 1.72 mg ml⁻¹ and 0.45 μg ml⁻¹ s⁻¹, respectively. Na⁺, Ca²⁺, EDTA and β-mercaptoethanol had no effect on the activity, while Hg²⁺, Cu²⁺, Co²⁺ strongly inhibited it. It is noteworthy that Bgl1C is a cold active enzyme that retains about 61% of its maximum activity at 10°C. Structural model of Bgl1C revealed that some amino acids (glycine, alanine, serine, valine) concerned with plasticity and flexibility were located around the active sites, this may contributed to the cold adaption of Bgl1C. These favorable features make Bgl1C a potential candidate for various industrial applications.     

Structure-based design and synthesis of novel P2/P3 modified,non-peptidic β-secretase (BACE-1) inhibitors

Starting from peptidomimetic BACE-1 inhibitors, the P2 amino acid including the P2/P3 peptide bond was replaced by a rigid 3-aminomethyl cyclohexane carboxylic acid. Co-crystallization revealed an unexpected binding mode with the P3/P4 amide bond placed into the S3 pocket resulting in a new hydrogen bond interaction pattern. Further optimization based on this structure resulted in highly potent BACE-1 inhibitors with selectivity over BACE-2 and cathepsin D.     

Polymorphisms in PPARD, PPARG and APM1 associated with four types of Traditional Chinese Medicine constitutions

Based on the theory of constitution of Traditional Chinese Medicine (TCM), the human population is divided into nine constitutions including one balanced constitution (Normality) and eight unbalanced constitutions (Yang-deficiency, Yin-deficiency, Phlegm-wetness, Qi-deficiency, Wetness-heat, Blood stasis, Depressed constitution, and Inherited special constitution). Different constitutions have specific metabolic features and different susceptibility to certain diseases. However, whether a genetic basis accounts for such constitution classification is yet to be determined. Here we performed a genetic study to assess the association between genetic variations of metabolic genes including PPARD, PPARG and APM1 and the constitutions. A total of 233 individuals of the Han population in China were classified into four groups, Normality, Yang-deficiency, Yin-deficiency and Phlegm-wetness with whom 23 single nucleotide polymorphisms (SNPs) in the three genes were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Biased distribution of PPARD rs2267669 and rs2076167, APM1 rs7627128 and rs1063539 in Yang-deficiency, PPARG Pro12Ala in Yin-deficiency and PPARD rs2076167, APM1 rs266729 and rs7627128 in Phlegm-wetness were observed. The frequencies of Haplotype13 (Hap13) of PPARG in Yin-deficiency, Hap25 of APM1 in Yang-deficiency and Hap2 of PPARD and Hap14 of PPARG in Phlegm-wetness, were significantly different from those in Normality, suggesting those might be group-associated haplotypes. These results suggested that single SNP and haplotypes of PPARD, PPARG and APM1 may underlie the genetic basis of the constitutions classified in TCM.     

Quality of life in mothers of children with oppositional defiant symptoms: a community sample

Background Children with oppositional defiant symptoms (ODS) are highly related to parental stress, especially in mothers. This study is the first to investigate the quality of life (QOL) of mothers of children with ODS in a community sample.Methods Randomly selected mothers of children attending an elementary school were contacted, and 387 who completed the questionnaire participated in this study. The children's ODS status was determined by the maternal rating of the Chinese Swanson, Nolan, and Pelham rating scale, version IV. The mothers' QOL was estimated by maternal reports from the World Health Organization Quality of Life - BREF (WHOQOL-BREF) instrument. The relationship between the children's ODS status and maternal QOL was examined by analysis of covariance (ANCOVA) with the participants' sociodemographic factors as covariables.Results Sixty-three children, mostly boys, met the screening criteria for ODS. The positive screening rate for ODS was 16.49%. The children's ODS status was a significant predictor for the maternal physical capacity, psychological wellbeing and environment domains of QOL. Mothers of children with ODS who rented a house were younger and had lower education levels and worse QOL in all domains.Conclusion A high positive screening rate for ODS children in the elementary school and a relationship between poor maternal QOL and children's ODS were found in this study. Routine screening for ODS in children and mental health services for these children and their mothers are warranted.