Screening of Multimeric β-Xylosidases from the Gut Microbiome of a Higher Termite, \u3cem\u3eGlobitermes brachycerastes\u3c/em\u3e

Termite gut microbiome is a rich reservoir for glycoside hydrolases, a suite of enzymes critical for the degradation of lignocellulosic biomass. To search for hemicellulases, we screened 12,000 clones from a fosmid gut library of a higher termite, Globitermes brachycerastes. As a common Southeastern Asian genus, Globitermes distributes predominantly in tropical rain forests and relies on the lignocellulases from themselves and bacterial symbionts to digest wood. In total, 22 positive clones with β-xylosidase activity were isolated, in which 11 representing different restriction fragment length polymorphism (RFLP) patterns were pooled and subjected to 454 pyrosequencing. As a result, eight putative β-xylosidases were cloned and heterologously expressed in Escherichia coli BL21 competent cells. After purification using Ni-NTA affinity chromatography, recombinant G. brachycerastes symbiotic β-xylosidases were characterized enzymatically, including their pH and temperature optimum. In addition to β-xylosidase activity, four of them also exhibited either β-glucosidase or α-arabinosidases activities, suggesting the existence of bifunctional hemicellulases in the gut microbiome of G. brachycerastes. In comparison to multimeric protein engineering, the involvement of naturally occurring multifunctional biocatalysts streamlines the genetic modification procedures and simplifies the overall production processes. Alternatively, these multimeric enzymes could serve as the substitutes for β-glucosidase, β-xylosidase and α-arabinosidase to facilitate a wide range of industrial applications, including food processing, animal feed, environment and waste management, and biomass conversion

PO-108 The relationship between Obesity and Sleep behavior in adolescents

Objective With the increasing detection rate of overweight and obesity in adolescents, many kinds of fat-related hazards affect the quality of life. This paper aims to study the relationship between overweight and obesity and sleep behavior in adolescents. To provide theoretical basis for adolescent obesity intervention policy according to the relevant links. Methods A questionnaire survey was conducted on 156 (84 males, 72 females) aged 12 to 18 years old to collect information on their basic physical condition and sleep related behaviors, and the questionnaire was collected on the spot. Subjects were divided into three groups according to BMI: normal, overweight and obese. The gender and BMI groups were analyzed and compared. Results  (1) Obesity The rate of obesity in boys was higher than that in girls , (P < 0. 05). (2). The rate of staying up late during workday (71.7%) and early rising (83.0%) in obese group was higher than that in girls (83.0%). In obese group, the sleeping time was longer (25.16 ±6.3min) and had no siesta behavior (30.8%). In normal group, 15-30min (38.6%), (P < 0.05). (3) BMI (29.86 ±7.53) in boys was significantly higher than that in girls (26.85 ±5.50), (), while in normal group (38.6%), (P < 0.05). (3), BMI in boys (29.86 ±7.53) was significantly higher than that in girls (26.85 ±5.50), ( P < 0.05). Male students with no siesta behavior and nap time in 15-30 minutes accounted for more (25. 5%), while female students had more lunch break time between 30 and 60 minutes (36.9%). (4). Male students' nap time and sleep duration were negatively correlated with BMI , (P < 0. 05). BMI was proportional to nap time and sleep time, but was inversely proportional to sleep time , (P < 0. 05). Conclusions Sleep behavior of adolescent boys and girls may have an effect on body weight status. Staying up late, lack of sleep and lack of lunch time will aggravate obesity and reduce sleep barrier. In addition, shortening sleep time can improve overweight and obesity status

Mutual-anonymity and Authentication Key Agreement Protocol

Abstract: According to the characteristics of trusted computation, we proposed an efficient pseudonym ring signature-based authentication and key agreement protocol with mutual anonymity. The use of ring signature can hide the identity information of communicating parties and effectively prevent the leakage of private information. Finally we derive a shared session key between them for their future secure communication especially in the trusted computation environment. Our protocol reaches the level of universally composable security and is more efficient

Notch1 is required for hypoxia-induced proliferation, invasion and chemoresistance of T-cell acute lymphoblastic leukemia cells

Background Notch1 is a potent regulator known to play an oncogenic role in many malignancies including T-cell acute lymphoblastic leukemia (T-ALL). Tumor hypoxia and increased hypoxia-inducible factor-1α (HIF-1α) activity can act as major stimuli for tumor aggressiveness and progression. Although hypoxia-mediated activation of the Notch1 pathway plays an important role in tumor cell survival and invasiveness, the interaction between HIF-1α and Notch1 has not yet been identified in T-ALL. This study was designed to investigate whether hypoxia activates Notch1 signalling through HIF-1α stabilization and to determine the contribution of hypoxia and HIF-1α to proliferation, invasion and chemoresistance in T-ALL. Methods T-ALL cell lines (Jurkat, Sup-T1) transfected with HIF-1α or Notch1 small interference RNA (siRNA) were incubated in normoxic or hypoxic conditions. Their potential for proliferation and invasion was measured by WST-8 and transwell assays. Flow cytometry was used to detect apoptosis and assess cell cycle regulation. Expression and regulation of components of the HIF-1α and Notch1 pathways and of genes related to proliferation, invasion and apoptosis were assessed by quantitative real-time PCR or Western blot. Results Hypoxia potentiated Notch1 signalling via stabilization and activation of the transcription factor HIF-1α. Hypoxia/HIF-1α-activated Notch1 signalling altered expression of cell cycle regulatory proteins and accelerated cell proliferation. Hypoxia-induced Notch1 activation increased the expression of matrix metalloproteinase-2 (MMP2) and MMP9, which increased invasiveness. Of greater clinical significance, knockdown of Notch1 prevented the protective effect of hypoxia/HIF-1α against dexamethasone-induced apoptosis. This sensitization correlated with losing the effect of hypoxia/HIF-1α on Bcl-2 and Bcl-xL expression. Conclusions Notch1 signalling is required for hypoxia/HIF-1α-induced proliferation, invasion and chemoresistance in T-ALL. Pharmacological inhibitors of HIF-1α or Notch1 signalling may be attractive interventions for T-ALL treatment

GWAS and WGCNA uncover hub genes controlling salt tolerance in maize (Zea mays L.) seedlings

Salt stress influences maize growth and development. To decode the genetic basis and hub genes controlling salt tolerance is a meaningful exploration for cultivating salt-tolerant maize varieties. Herein, we used an association panel consisting of 305 lines to identify the genetic loci responsible for Na+- and K+-related traits in maize seedlings. Under the salt stress, seven significant single nucleotide polymorphisms were identified using a genome-wide association study, and 120 genes were obtained by scanning the linkage disequilibrium regions of these loci. According to the transcriptome data of the above 120 genes under salinity treatment, we conducted a weighted gene co-expression network analysis. Combined the gene annotations, two SNaC/SKC (shoot Na+ content/shoot K+ content)-associated genes GRMZM2G075104 and GRMZM2G333183 were finally identified as the hub genes involved in salt tolerance. Subsequently, these two genes were verified to affect salt tolerance of maize seedlings by candidate gene association analysis. Haplotypes TTGTCCG-CT and CTT were determined as favorable/salt-tolerance haplotypes for GRMZM2G075104 and GRMZM2G333183, respectively. These findings provide novel insights into genetic architectures underlying maize salt tolerance and contribute to the cultivation of salt-tolerant varieties in maize

Mechanism of Beraprost Effects on Pulmonary Hypertension: Contribution of Cross-Binding to PGE2 Receptor 4 and Modulation of O2 Sensitive Voltage-Gated K+ Channels

Background: The purpose of this study is to elucidate mechanism(s) by which the orally active PGI2 analog, Beraprost (BPS), ameliorates pulmonary hypertension (PH). Prostaglandins are an important treatment for PH. Mechanisms of their action are not fully elucidated in relation to receptor subtype and effects on O2 sensitive Kv channels.Methods: Distal (3rd order and beyond) pulmonary arteries from chronically hypoxic rats and from humans with established PH were studied. Measurements included pulmonary haemodynamics and histology, vascular reactivity, prostanoid receptor expression and activity of the O2 sensitive Kv channels.Results: Prostacyclin receptor (IP), prostaglandin receptor E3 (EP3) and prostaglandin receptor E4 (EP4) are the main pulmonary artery receptor subtypes in both rat and human pulmonary arteries. Circulating levels of PGI2 and PGE2 were reduced in PH. PH was also associated with reduced receptor expression of IP but not of EP4. The effects on IP expression were overcome with BPS. Dilatory responses in PH to BPS were reduced in the presence of EP4 blockade. Expression and activity of oxygen sensitive Kv channels were reduced in pulmonary artery smooth muscle cell from rats with PH and humans with PAH and were also overcome by administration of BPS. Effects of BPS on oxygen sensitive Kv channels were reduced in the presence of EP4 blockade implicating the EP4 receptor, as well as the IP receptor, in mediating BPS effects.Conclusion: Reduced expression of pulmonary IP receptors and reduced activity of O2 sensitive Kv channels are found in PH in both humans and rats. The orally active prostacyclin analogue, BPS, is able to reverse these changes, partly through binding to the EP4 receptor

RAD51C facilitates checkpoint signaling by promoting CHK2 phosphorylation

The RAD51 paralogues act in the homologous recombination (HR) pathway of DNA repair. Human RAD51C (hRAD51C) participates in branch migration and Holliday junction resolution and thus is important for processing HR intermediates late in the DNA repair process. Evidence for early involvement of RAD51 during DNA repair also exists, but its function in this context is not understood. In this study, we demonstrate that RAD51C accumulates at DNA damage sites concomitantly with the RAD51 recombinase and is retained after RAD51 disassembly, which is consistent with both an early and a late function for RAD51C. RAD51C recruitment depends on ataxia telangiectasia mutated, NBS1, and replication protein A, indicating it functions after DNA end resection but before RAD51 assembly. Furthermore, we find that RAD51C is required for activation of the checkpoint kinase CHK2 and cell cycle arrest in response to DNA damage. This suggests that hRAD51C contributes to the protection of genome integrity by transducing DNA damage signals in addition to engaging the HR machinery

Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition