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Purpose Referring to global cancer statistics, the incidence of gastric cancer (GC) was ranked sixth; however, detailed mechanisms underlying its development were not thoroughly investigated. Previous studies have reported that inhibition of ubiquitin-specific peptidase 8 (USP8) induced degradation of several receptor tyrosine kinases, such as epidermal growth factor receptor (EGFR), embryonic stem cells (ESCs), etc. Nevertheless, the regulation of HER-2 by USP8 and the molecular mechanisms controlling their role in the pathogenesis of GC remain unknown. Patients and methods A total of 69 patients with histologically confirmed GC were recruited to satisfy the purpose of this study. Initially, tumor samples and GC cell lines were used to detect USP8 and HER-2 levels. Next, MTT and colony formation assays were applied to analyze cell proliferation capability. Cell migration and invasion ability were examined by transwell assays. To examine related mRNA and protein expressions, Western blot assays and quantitative real-time PCR (qRT-PCR) were performed. Immunofluorescence was used to detect the effect of USP8 inhibitor on GC cells. Finally, in vivo experiments were used to examine the effect of USP8 inhibitor. Results Patients with USP8 high-expression tumors have shown worse overall survival while opposite results found in patients with low USP8 expressions. Regarding disease prognosis, patients with low expression of USP8 and HER-2 were performed better prognosis, whereas those with overexpression of USP8 and HER-2 shown poor prognosis. USP8 inhibitor significantly inhibited HER-2 positive cell NCI-N87 proliferation and metastasis. In addition, USP8 stabilizes HER-2, preventing it from ubiquitin proteasome-mediated degradation. In vivo studies confirmed that the USP8 inhibitor inhibited HER-2 positive cell NCI-N87 tumor growth. However, it did not affect the HER2-negative cell MGC-803. Careful investigation unraveled that the USP8 inhibitor significantly inhibited NCI-N87 cell proliferation and metastasis via phosphatidylinositol-3-kinases/protein-serine-threonine kinase (PI3K/AKT) pathway. Conclusion The USP8 inhibited HER-2 positive GC cell proliferation and migration in vivo and in vitro and probably served as a novel potential therapeutic biomarker for HER-2 positive GC.

Background Ubiquitin specific peptidase 8 (USP8) has been reported to induce the degradation of several receptor tyrosine kinases such as epidermal growth factor receptor (EGFR), among which human epidermal growth factor receptor-3 (HER-3) is one of them. However, the role and functional mechanisms of USP8 and HER-3 in gastric cancer (GC) remain unknown. Objective To explore the function and mechanism of USP8 and HER-3 in the progression of GC. Materials and methods Eighty-eight patients with histologically confirmed GC were recruited for this study. Tumor samples and GC cell lines were used to detect USP8 and HER-3 levels. MGC803 (HER-3 negative GC cell) was selected as the control group and NCI-N87, MKN-45 and AGS (HER-3 positive GC cells) as the experimental group. USP8i and si-RNA were then used to down-regulate USP8 in each group. Apoptosis and cell-cycle experiments were performed to detect the effects of USP8 on GC cells. Cytotoxicity Assay Kit (MTT) and colony formation assays were used to analyze cell proliferation. Cell migration and invasion ability were examined by wound healing. The expression of related mRNA and protein was detected by Western blot and quantitative real-time PCR (qRT-PCR). In vivo experiments were used to examine the effect of USP8 and HER-3. Results Patients with high expression of USP8 or HER-3 tumors alone died earlier than those with low expression and the patients with both USP8 and HER-3 high expression had a shorter overall survival than those with the opposite pattern (both USP8 and HER-3 low expression). Down-regulation of USP8 inhibited cell proliferation and cell metastasis and also reduced the HER-3 expression. We also observed that down-regulation of USP8 inhibited the proliferation of GC cells which highly expressed HER-3. Moreover, down-regulation of USP8 could promote the apoptosis of HER3-positive GC cells and inhibit the proliferation of them by affecting the cell-cycle. In vivo studies demonstrated that down-regulation of USP8 inhibited HER-3 positive tumors growth. Conclusion Down-regulation of USP8 inhibits HER-3 positive GC cells proliferation in vivo and in vitro, which indicate that USP8 represents a feasible choice as a therapeutic target for HER-3 positive GC cells.

Sb2S3/perylene diimide derivatives composite micro-spheres composed of slight dendrites were synthesized by solvothermal reaction. Perylene diimide derivative with two carboxyl groups at amine position as morphology-controlling reagent is the key factor for determining the microscopic morphology of Sb2S3 in this system. Time-dependent experiments have been conducted to track the formation of Sb2S3 micro-spheres. Moreover, the composite material showed an excellent sensitivity of 29.8 μA mM−1 cm2 with a low detection limit of 50 pM, it also showed better stability and selectivity in hydrazine detection. This approach not only regulate the morphology and composition of Sb2S3 submicron materials effectively, but also provide new ideas for the manufacture of metal sulfide- perylenediimide amino acid derivative materials, which will be suitable for sensing, catalysis, and photovoltaic applications.

The first report of the cloning and characterization of the flowering time-regulating genes GI and CO homologs from loquat. Flowering time is critical for successful reproduction in plants. In fruit trees, it can also influence the fruit yield and quality. In the previous work, we cloned the important florigen one EdFT and two EdFDs from wild loquat (Eriobotrya deflexa Nakai forma koshunensis); however, the upstream transcription factors are still unknown. The photoperiod pathway genes GIGANTEA (GI) and CONSTANS (CO) have been reported to mainly regulate FT expression in model plants. In this work, we first cloned photoperiod pathway orthologs EdGI and EdCO from E. deflexa Nakai f. koshunensis. Phylogenetic analysis showed they are highly conserved to those from Arabidopsis. They are mainly expressed in the leaves. The EdGI and EdCO were localized in the nucleus. Their expression showed in photoperiodic regulation, while the EdCO transcripts reached the peak at different periods from that of CO in Arabidopsis. Moreover, EdCO significantly activated the EdFT promoter activity. In the transgenic Arabidopsis, downstream-flowering genes like FT and AP1 were obviously upregulated, and consequently resulted in early-flowering phenotype compared to the wild type. These data revealed that the EdGI and EdCO may play a similar role as GI and CO in Arabidopsis, and regulate flower initiation in loquat.

Aquaporins (AQPs) are essential membrane proteins involved in seed maturation and germination, stomata movement, photosynthesis, and regulation of plant flowering processes. Pitaya flowers are open at night and wither at daybreak, which shows an obvious circadian rhythm. In this study, a comprehensive genome-wide analysis of AQPs in Hylocereus undantus was conducted to screen key genes associated with flowering processes. A total of 33 HuAQP genes were identified from the H. undantus genome. The 33 HuAQPs were grouped into four subfamilies: 10 PIPs, 13 TIPs, 8 NIPs, and 2 SIPs, which were distributed on 9 out of 11 pitaya chromosomes (Chr) (except for Chr7 and Chr10). Results from expression profiles showed that HuNIP6;1 may be involved in pitaya’s floral opening. HuNIP6;1 was localized exclusively in the cell membrane. Overexpression of HuNIP6;1 in Arabidopsis thaliana significantly promoted early flowering through regulating negative flowering regulators of MJM30, COL9, and PRR5, suggesting that HuNIP6;1 plays key roles in regulating flowering time. The present study provides the first genome-wide analysis of the AQP gene family in pitaya and valuable information for utilization of HuAQPs.

Perylene diimide and its various derivatives tend to form stable anion radicals, which can usually form a variety of aggregates with special properties. Herein, we reported synthesis and properties of the benzo[ghi]perylene trimide and its anion radical π-bonded dimer. The dimer exhibited high stable in solid status and in most organic solvents, but conversion of L-type π-bonded dimer to face to face type π-bonded dimer or π-stacked oligomer occurs in dimethyl formamide solution. The temperature and crystallization influenced the π-bonded length in the dimer and the partial memory can be reserved and probed in solution at room temperature.

The D-mannose/L-galactose pathway for the biosynthesis of vitamin C (L-ascorbic acid; AsA) has greatly improved the understanding of this indispensable compound in plants, where it plays multifunctional roles. However, it is yet to be proven whether the same pathway holds for all the different organs of plants, especially the fruit-bearing plants, at different stages of development. Micro-Tom was used here to elucidate the mechanisms of AsA accumulation and regulation in tomato fruits. The mRNA expression of the genes in the D-mannose/L-galactose pathway were inversely correlated with increasing AsA content of Micro-Tom fruits during ripening. Feeding L-[6-(14)C]AsA to Micro-Tom plants revealed that the bulk of the label from AsA accumulated in the source leaf was transported to the immature green fruits, and the rate of translocation decreased as ripening progressed. L-Galactose feeding, but neither D-galacturonate nor L-gulono-1,4-lactone, enhanced the content of AsA in immature green fruit. On the other hand, L-galactose and D-galacturonate, but not L-gulono-1,4-lactone, resulted in an increase in the AsA content of red ripened fruits. Crude extract prepared from insoluble fractions of green and red fruits showed D-galacturonate reductase- and aldonolactonase-specific activities, the antepenultimate and penultimate enzymes, respectively, in the D-galacturonate pathway, in both fruits. Taken together, the present findings demonstrated that tomato fruits could switch between different sources for AsA supply depending on their ripening stages. The translocation from source leaves and biosynthesis via the D-mannose/L-galactose pathway are dominant sources in immature fruits, while the alternative D-galacturonate pathway contributes to AsA accumulation in ripened Micro-Tom fruits.

Ascorbate (AsA) is a redox buffer and enzyme cofactor with various proposed functions in stress responses and growth. The aim was to identify genes whose transcript levels respond to changes in leaf AsA. The AsA-deficient Arabidopsis mutant vtc2-1 was incubated with the AsA precursor L-galactono-1,4-lactone (L-GalL) to increase leaf AsA concentration. Differentially expressed genes screened by DNA microarray were further characterized for AsA responsiveness in wild-type plants. The analysis of 14 candidates by real-time PCR identified an aspartyl protease gene (ASP, At1g66180) and a C3HC4-type RING zinc finger gene (AtATL15, At1g22500) whose transcripts were rapidly responsive to increases in AsA pool size caused by L-GalL and AsA supplementation and light. Transgenic Arabidopsis plants expressing an AtATL15 promoter::luciferase reporter confirmed that the promoter is L-GalL, AsA, and light responsive. The expression patterns of ASP and AtATL15 suggest they have roles in growth regulation. The promoter of AtATL15 is responsive to AsA status and will provide a tool to investigate the functions of AsA in plants further.

Euglena gracilis lacks a catalase and contains a single APX (ascorbate peroxidase) and enzymes related to the redox cycle of ascorbate in the cytosol. In the present study, a full-length cDNA clone encoding the Euglena APX was isolated and found to contain an open reading frame encoding a protein of 649 amino acids with a calculated molecular mass of 70.5 kDa. Interestingly, the enzyme consisted of two entirely homologous catalytic domains, designated APX-N and APX-C, and an 102 amino acid extension in the N-terminal region, which had a typical class II signal proposed for plastid targeting in Euglena . A computer-assisted analysis indicated a novel protein structure with an intramolecular dimeric structure. The analysis of cell fractionation showed that the APX protein is distributed in the cytosol, but not the plastids, suggesting that Euglena APX becomes mature in the cytosol after processing of the precursor. The kinetics of the recombinant mature FL (full-length)-APX and the APX-N and APX-C domains with ascorbate and H 2 O 2 were almost the same as that of the native enzyme. However, the substrate specificity of the mature FL-APX and the native enzyme was different from that of APX-N and APX-C. The mature FL-APX, but not the truncated forms, could reduce alkyl hydroperoxides, suggesting that the dimeric structure is correlated with substrate recognition. In Euglena cells transfected with double-stranded RNA, the silencing of APX expression resulted in a significant increase in the cellular level of H 2 O 2 , indicating the physiological importance of APX to the metabolism of H 2 O 2 .

Loquat (Eriobotrya japonica ) is a subtropical tree with commercially important fruit and with leaves that have medicinal uses against cough and asthma. Leaves contain significant amounts of phenols, flavonoids, triterpene acids, and polysaccharides. However, information of the triterpene acids and polysaccharides in leaves is limited. In this study, the contents of five major triterpene acids and total polysaccharides in the leaves of 11 species of Eriobotrya were determined using RP-HPLC and phenol-sulfuric acid method, respectively. Total concentration of triterpene acids varied from 8.38 to 22.35 mg g-1 DW. The concentration of triterpene acids was greater than 20 mg g-1 DW in E. bengalensis, E. prinoides and E. fragrans , and it was less than 10.0 mg g-1 DW in E. elliptica . Different drying temperature (40-80°C) of leaves did not affect the content of polysaccharides with highest content (80.8 mg g-1 DW) from E. prinoides . The contents of triterpene acid in six wild species and polysaccharides in 5 wild species were higher than that in cultivated loquat.

Accumulation of carotenoids in peel and pulp of the yellow-fleshed loquat ‘Zaozhong 6’ (ZZ6) and the white-fleshed loquat ‘Baiyu’ (BY) were tracked during different fruit development stages, and the expression of 15 carotenogenic genes were analyzed. During loquat fruit ripening the fresh weight content of β- carotene in peel and pulp of ZZ6 increased gradually and peaked at the fully ripe stage, reaching 68.53 µg⋅g −1 FW in the peel and 11.92 µg⋅g −1 FW in the pulp. In BY, the content of β -carotene in the peel increased and peaked at the fully ripe stage, reaching 38.89 µg⋅g −1 FW, while it decreased in the pulp from the original 0.47 µg⋅g −1 FW and reduced to 0.29 µg⋅g −1 FW. The content of β -cryptoxanthin in the peel and pulp of ZZ6 and BY both increased steadily, and peaked at the fully ripe stage; however, the content of lutein decreased in the peel of ZZ6 and increased in the pulp, but in BY, it dropped and then rose in the peel. There was no significant change of β -cryptoxanthin in the pulp of BY. After the breaker stage, the mRNA levels of phytoene synthase ( PSY ) and chromoplast-specific lycopene β -cyclase ( CYCB ) were higher in the peel, while CYCB and β -carotene hydroxylase ( BCH ) mRNAs were higher in the flesh of ZZ6, compared with BY. The results showed that the expression level of PSY , CYCB , and BCH appeared to cooperatively regulate the accumulation of carotenoids.