Identification and characterization of PP2C phosphatase SjPtc1 in Schistosoma japonicum

Protein phosphorylation, regulated by protein kinases and protein phosphatases, is crucial for protein structure and function in eukaryotic organisms. Type 2C protein phosphatase (PP2C) belongs to the serine/threonine phosphatase family and its activities require the presence of a divalent magnesium or manganese ion. In the present study, a potential PP2C phosphatase (SjPtc1) was identified in Schistosoma japonicum. The SjPTC1 gene was found to be highly expressed in adult worms. A recombinant SjPtc1 protein showed typical PP2C phosphatase activity. Heterologous SjPTC1 expression reversed the sensitivity of yeast ptc1 null mutants toward H₂O₂, ZnCl₂, cisplatin, and rapamycin. Collectively, the results suggest that SjPtc1 may take part in the regulation of cellular responses to oxidative stress, DNA damage stress, and the TOR (target of rapamycin) signaling pathway.     

Preliminary comparison of atmospheric CO2 enhancement to photosynthesis of Pyropia yezoensis (Bangiales,Rhodophyta) leafy thalli and filamentous thalli

Intertidal macroalgae are submerged in seawater at high tide and exposed to air at low tide. When they are exposed to the air, CO₂ is the main inorganic carbon source. In this study, the photosynthetic performances of PSI and PSII were measured in different generations of Pyropia yezoensis (leafy thalli and filamentous thalli) that had been exposed to air containing different CO₂ concentrations. Changes in photosynthesis during dehydration and salt treatment under the different CO₂ concentrations were also analyzed. The results showed that in leafy thalli, the effective photochemical quantum yield of PSII (YII) was enhanced as CO₂ increased, which suggested that CO₂ assimilation was enhanced and that they can utilize CO₂ in the air directly, even when they are subjected to moderate stress. These findings could explain why, in P. yezoensis aquaculture, moderate exposure to air does not lead to a decrease in crop yield. However, in filamentous thalli, there were no significant differences in YII at the CO₂ concentrations tested. The expression of genes involved in the Calvin cycle in leafy thalli was higher than that in filamentous thalli. CO₂ uptake and biomass of P. yezoensis leafy thalli is larger than filamentous thalli, which may be due to its different carbon utilization mechanism and the adaptation of intertidal environment in the evolutionary process.     

The association of garlic with Helicobacter pylori infection and gastric cancer risk: A systematic review and meta‐analysis

Background

Garlic may be protective against Helicobacter pylori infection and gastric cancer development. We conducted this study to quantitatively update evidence on garlic intake and gastric cancer with the inclusion of most recent cohort studies and qualitatively summarize epidemiological studies of garlic consumption and Helicobacter pylori infection.

Materials and Methods

PubMed, Embase, MEDLINE, and Cochrane Library were searched on April 2018. We conducted a meta‐analysis to determine whether garlic intake reduced gastric cancer risk using random‐effect models and a systematic review to summarize evidence on the association between garlic consumption and Helicobacter pylori infection. Risk of bias was assessed using tools of Cochrane risk of bias and Robins‐I for randomized and nonrandomized studies, respectively.

Results

Meta‐analysis of 18 studies (142 921 subjects) demonstrated high garlic consumption (as comparing the highest category to the lowest) was associated with a reduced gastric cancer risk (OR = 0.51, 95% CI = 0.44‐0.57). This association became nonsignificant if only derived from the prospective studies (OR = 0.95, 95% CI = 0.66‐1.24). Thirteen studies (4889 participants) were included in the systematic review for garlic consumption and Helicobacter pylori infection; ten of which found no significant results. The majority of these studies were poor in quality given the small sample size and high risk of bias.

Conclusions

Pooled evidence, mainly from case‐control studies, suggested a significant inverse association of garlic intake with gastric cancer risk. Given the limitations of included studies, current epidemiological evidence is not sufficient to reach any definite conclusion regarding the association of garlic with Helicobacter pylori infection.     

Unraveling Geometrical Site Confinement in Highly Efficient Iron‐Doped Electrocatalysts toward Oxygen Evolution Reaction

Introduction of iron in various catalytic systems has served a crucial function to significantly enhance the catalytic activity toward oxygen evolution reaction (OER), but the relationship between material properties and catalysis is still elusive. In this study, by regulating the distinctive geometric sites in spinel, Fe occupies the octahedral sites (Fe³⁺_(Oh)) and confines Co to the tetrahedral site (Co²⁺_(Td)), resulting in a strikingly high activity (η_{j = 10 mA cm}^?2 = 229 mV and η_{j = 100 mA cm}^?2 = 281 mV). Further enrichment of Fe ions would occupy the tetrahedral sites to decline the amount of Co²⁺_(Td) and deteriorate the OER activity. It is also found that similar tafel slope and peak frequency in Bode plot of electrochemical impedance spectroscopy indicate that Co²⁺_(Td) ions are primarily in charge of water oxidation catalytic center. By means of electrochemical techniques and in situ X‐ray absorption spectroscopy, it is proposed that Fe³⁺_(Oh) ions mainly confine cobalt ions to the tetrahedral site to restrain the multipath transfer of cobalt ions during the dynamic structural transformation between spinel and oxyhydroxide, continuously activating the catalytic behavior of Co²⁺_(Td) ions. This material‐related insight provides an indication for the design of highly efficient OER electrocatalysts.     

Pathogenicity and molecular characterization of a fowl adenovirus 4 isolated from chicken associated with IBH and HPS in China

Background

Since July in 2015, an emerging infectious disease, Fowl adenovirus (FAdV) species C infection with Hepatitis-Hydropericardium syndrome was prevalent in chicken flocks in China. In our study, one FAdV strain was isolated from commercial broiler chickens and was designated as SDSX1.The phylogenetic information, genetic mutations and pathogenicity of SDSX1 were evaluated.

Results

The phylogenetic analysis indicated that SDSX1 is a strain of serotype 4, FAdV-C. The amino acid analysis of fiber-2 showed that there were more than 20 mutations compared with the non-virulent FAdV-C strains. The pathogenic evaluation of SDSX1 showed that the mortality of one-day-old chickens inoculated SDSX1 was 100%. The typical histopathological changes of SDSX1 were characterized by the presence of basophilic intranuclear inclusion bodies in hepatocytes. The virus copies in different tissues varied from10⁷ to 10¹¹ per 100?mg tissue and liver had the highest virus genome copies.

Conclusion

In conclusion, the isolate SDSX1, identified as FAdV-4, could cause one-day-old chicks’ typical inclusion body hepatitis (IBH) and hepatitis-hydropericardium syndrome (HHS) with 100% mortality. The virus genome loads were the highest in the liver. Molecular analysis indicated that substitutions in fiber-2 proteins may contribute to the pathogenicity of SDSX1.

     

Molecular cloning and spatiotemporal expression of <Emphasis Type="BoldItalic">APETALA1</Emphasis>-like gene in <Emphasis Type="BoldItalic">Lonicera macranthoides</Emphasis>

APETALA1 (AP1), a floral meristem identity gene controls the flowering time and floral transition, and plays an important role in inflorescence and floral organ development. The full-length cDNA for AP1 was obtained by rapid amplification of the cDNA ends (RACE) so that the roles of AP1 in Lonicera macranthoides (Lm-AP1) could be better understood. AP1 (accession number in GenBank: MF418642) consisted of a 729-bp open reading frame encoding a protein that contained 242 amino acids, had a deduced molecular mass of 27.9919 kDa and a theoretical isoelectric point of 8.75. No signal peptide or transmembrane domains were detected in the sequences located in the nucleus, but it contained conserved sequences for MADS and the K-box. In the secondary structure, the \(\alpha \)-helix accounts for 60.74%, the \(\beta \)-turn 3.72%. The real-time polymerase chain reaction revealed that AP1 was more highly expressed in flowers, especially at the fourth flowering stage, which implied that it may play a role in flower development. Other L. macranthoides organs, such as stems and leaves, also expressed AP1. This research provided the basis for further analysis of the AP1 functional mechanism during L. macranthoides development.