Antioxidative properties of bayberry tannins with different mean degrees of polymerization: Controlled degradation based on hydroxyl radicals.

The antioxidant properties of condensed tannins (CTs) are closely related to the mean degree of polymerization (mDP), and CTs with low mDP show stronger antioxidant effects. Therefore, obtaining CTs with a low mDP are very meaningful in improving their antioxidant properties and utilization. In this study, hydroxyl radicals generated by the decomposition of hydrogen peroxide under UV irradiation were used to degrade bayberry tannins in a clean and controllable manner. Taking the formaldehyde reactivity as an index to control the mDP of the degradation product, the changes in antioxidant properties of bayberry tannins with different mDP were studied by the method of 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), and 2,2-azido-di(3-ethyl-benzothiazole-6-sulfonic acid)diammonium salt (ABTS). Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), gel permeation chromatography (GPC), carbon nuclear magnetic resonance (13C NMR), and reversed-phase HPLC-ESI-MS were used to characterize the mDP, molecular weight (Mw), and chemical structure of the degradation products of bayberry tannins in different degradation stages. Results showed that hydroxyl radicals could cause significant degradation of bayberry tannins, and the controllable degradation of bayberry tannins could be achieved with the formaldehyde reactivity as an index. At the degradation times of 0, 2, 4, 6, and 8 h, the mDP (Mw) of the degradation products were as follows: 5.22 (2457), 4.36 (1895), 3.36 (1534), 2.87 (1153), and 1.78 (813), respectively. The antioxidant activity of the degraded product increased with the decrease in the mDP, and the degraded products had the largest formaldehyde reactivity and the best oxidation resistance when degraded for 6 h. This study provided a new method to achieve clean and controllable degradation of tannins and supported those tannins with low mDP could provide higher antioxidant activity.

Oncogenic signaling pathway mediated by Notch pathway-related genes induces immunosuppression and immunotherapy resistance in hepatocellular carcinoma.

The Notch pathway is a highly conserved signaling pathway involved in the regulation of cell proliferation and differentiation. However, the relationships between Notch pathway-related genes (NPRGs), immunosuppression, and immunotherapy resistance of hepatocellular carcinoma (HCC) remain unclear. Gene expression data and clinical information were extracted from GSE14520, GSE36376, GSE76427, LIRI-JP, TCGA-LIHC, GSE20140, GSE27150, and IMvigor210 datasets. A consensus clustering analysis based on 10 NPRGs was performed to determine the molecular subtypes, and then a notchScore was constructed based on differentially expressed and prognostic genes between molecular subtypes. Two molecular subgroups with significantly distinct survival and immune cell infiltration were identified. Then, a notchScore was constructed to quantify the Notch index of each patient with HCC. Next, we investigated the correlations between the clinical characteristics and the notchScore using logistic regression. Furthermore, multivariate Cox analysis showed that a high notchScore was an independent predictor of poor overall survival (OS) in the TCGA and LIRI-JP datasets and was associated with higher pathological stages. Additionally, a high notchScore was associated with higher immune cells, higher ESTIMATE score, higher immune score, higher stromal score, higher immune checkpoint, and lower tumor purity, which was consistent with the "immunity tidal model theory." Importantly, a high notchScore was sensitive to immunotherapy. Additionally, GSEA indicated that several GO and KEGG items associated with apoptosis, immune-related pathways, and cell cycle signal pathways were significantly enriched in the high notchScore phenotype pathway. Our findings propose that a high notchScore is a prognostic biomarker and correlates with immune infiltration and sensitivity to immunotherapy in HCC.

Antioxidant Properties of Larch Tannins with Different Mean Polymerization Degrees: Controlled Degradation Based on Hydroxyl Radical Degradation.

Hydroxyl radical produced by hydrogen peroxide decomposition under UV radiation was used to degrade larch tannins in an environmentally friendly manner. The formaldehyde reactivity of the degraded products was used as an index to control the mean degree of polymerization (mDP) of the degraded products, and the effects of different mDP on the antioxidant activity of tannins were studied. Results showed that hydroxyl radical could significantly reduce the degree of polymerization (DP) and molecular weight (Mw) of larch tannins, and the mDP and Mw of degraded products could be controlled by considering the formaldehyde reactivity as the index. The antioxidant activity of larch tannins increased with the decrease in mDP. When the degradation time was 6 h, the formaldehyde reactivity was the highest at 0.823. The antioxidant activity of the degraded product was excellent, and the free radical scavenging rate was more than 98%.

LncRNA LINC00460 takes a stimulating role on hepatocellular carcinoma stemness property.

Abundant researches have stated that long noncoding RNAs (lncRNAs) are crucial molecules in intricate progression of various cancers in terms of their influence on cell stemness. However, no research has discussed the role of LINC00460 in the stemness of hepatocellular carcinoma (HCC). RT-qPCR and western blot were utilized to respectively examine the RNA and protein levels. Aldehyde dehydrogenase 1 (ALDH1) assays and sphere formation assay were performed to detect cell stemness property in vitro and in vivo subcutaneous xenograft tumor assay was performed to detect tumor growth. Interaction between RNAs was explored by luciferase reporter assays and RNA pull-down assays. Our results showed that LINC00460 was markedly over-expressed in HCC and silencing LINC00460 impaired cell stemness. Additionally, LINC00460 knockdown curbed proliferation, migration, invasion and epithelial-to-mesenchymal transition (EMT) and drove apoptosis of HCC cells. Further, LINC00460 bound to miR-503-5p and miR-654-3p to protect t-complex 1 (TCP1) from being inhibited by miR-503-5p/miR-654-3p. Rescue experiments confirmed the effect of LINC00460/miR-503-5p/miR-654-3p/TCP1 on HCC cell stemness. In conclusion, LINC00460 aggravated cell stemness in HCC via targeting miR-503-5p/miR-654-3p and TCP1, suggesting that LINC00460 may work as a potential signature for cell stemness in HCC.[Figure: see text].

MiR-379-5p targets microsomal glutathione transferase 1 (MGST1) to regulate human glioma in cell proliferation, migration and invasion and epithelial-mesenchymal transition (EMT).

BACKGROUND: Glioma is one of the most malignant tumors worldwide. This study was aimed to study the effect of miR-379-5p/MGST1 on cell proliferation, migration, invasion and EMT in glioma. METHODS: RT-qPCR detected the expression of miR-379-5p and MGST1 in RNA level in glioma cell lines. Bioinformatic analysis was made to explore the associations between miR-379-5p and MGST1 while survival analysis was made with regards to MGST1 expression in glioma patients. Western blot analysis was applied to measure the EMT changes. MTT examined the cell viability. Transwell was used to detect the cellular invasion and migration. The binding sites between miR-379-5p and MGST1 were validated by luciferase reporter assays. RESULTS: miR-379-5p expression was lower in glioma cells. MiR-379-5p increase inhibited the viability, migration, invasion and EMT while inhibition of miR-379-5p showed a reverse effect. MGST1 inhibition curbed the cell functions. MiR-379-5p targeted and regulated MGST1 expression. Lower MGST1 is related to higher survival rate. CONCLUSION: miR-379-5p could regulate glioma cell viability, migration, invasion and EMT through MGST1, suggesting that miR-379-5p/MGST1 axis might function in the regulation of glioma progression.

Long noncoding RNA nuclear-enriched abundant transcript 1 regulates proliferation and apoptosis of neuroblastoma cells treated by cisplatin by targeting miR-326 through Janus kinase/signal transducer and activator of transcription 3 pathway.

Neuroblastoma is a common malignancy and frequently affects children, leading to a low survival rate. Long noncoding RNAs (lncRNAs) are reported to be closely related to cancer progression. The purpose of this study was to explore a novel mechanism of lncRNA nuclear-enriched abundant transcript 1 (NEAT1) in neuroblastoma. NEAT1 was upregulated in neuroblastoma cell lines (IMR32 and SK-N-SH). Overexpression of NEAT1 increased proliferation inhibited by cisplatin and decreased apoptosis promoted by cisplatin. MicroRNA-326 (miR-326) was a target of NEAT1 and miR-326 reintroduction abolished the effects of NEAT1 overexpression on cell proliferation and apoptosis. Moreover, NEAT1 overexpression activated Janus kinase/signal transducer and activator of transcription 3 (JAK1/STAT3) signaling pathway through absorbing miR-326. Besides, NEAT1 overexpression promoted tumor growth in vivo through stimulating the expression of p-JAK1 and p-STAT3 but inhibiting miR-326 expression. NEAT1 accelerated proliferation and weakened apoptosis of neuroblastoma cells treated by cisplatin by targeting miR-326 through activating JAK1/STAT3 signaling pathway, suggesting that NEAT1 was a potential biomarker against neuroblastoma.

A Hazard Analysis of Class I Recalls of Infusion Pumps.

BACKGROUND: The adverse event report of medical devices is one of the postmarket surveillance tools used by regulators to monitor device performance, detect potential device-related safety issues, and contribute to benefit-risk assessments of these products. However, with the development of the related technologies and market, the number of adverse events has also been on the rise, which in turn results in the need to develop efficient tools that help to analyze adverse events monitoring data and to identify risk signals. OBJECTIVE: This study aimed to establish a hazard classification framework of medical devices and to apply it over practical adverse event data on infusion pumps. Subsequently, it aimed to analyze the risks of infusion pumps and to provide a reference for the risk management of this type of device. METHODS: The authors define a general hierarchical classification of medical device hazards. This classification is combined with the Trace Intersecting Theory to form a human-machine-environment interaction model. Such a model was applied to the dataset of 2001 to 2017 class I infusion pump recalls extracted from the Food and Drug Administration (FDA) website. This dataset does not include cases involving illegal factors. RESULTS: The proposed model was used for conducting hazard analysis on 70 cases of class I infusion pump recalls by the FDA. According to the analytical results, an important source of product technical risk was that the infusion pumps did not infuse accurate dosage (ie, over- or underdelivery of fluid). In addition, energy hazard and product component failure were identified as the major hazard form associated with infusion pump use and as the main direct cause for adverse events in the studied cases, respectively. CONCLUSIONS: The proposed human-machine-environment interaction model, when applied to adverse event data, can help to identify the hazard forms and direct causes of adverse events associated with medical device use.

Enhancing succinic acid biosynthesis in Escherichia coli by engineering its global transcription factor, catabolite repressor/activator (Cra).

This study was initiated to improve E. coli succinate production by engineering the E. coli global transcription factor, Cra (catabolite repressor/activator). Random mutagenesis libraries were generated through error-prone PCR of cra. After re-screening and mutation site integration, the best mutant strain was Tang1541, which provided a final succinate concentration of 79.8 ± 3.1 g/L: i.e., 22.8% greater than that obtained using an empty vector control. The genes and enzymes involved in phosphoenolpyruvate (PEP) carboxylation and the glyoxylate pathway were activated, either directly or indirectly, through the mutation of Cra. The parameters for interaction of Cra and DNA indicated that the Cra mutant was bound to aceBAK, thereby activating the genes involved in glyoxylate pathway and further improving succinate production even in the presence of its effector fructose-1,6-bisphosphate (FBP). It suggested that some of the negative effect of FBP on Cra might have been counteracted through the enhanced binding affinity of the Cra mutant for FBP or the change of Cra structure. This work provides useful information about understanding the transcriptional regulation of succinate biosynthesis.

Regulating ehrlich and demethiolation pathways for alcohols production by the expression of ubiquitin-protein ligase gene HUWE1.

Ehrlich and demethiolation pathways as two competing branches converted amino acid into alcohols. Controlling both pathways offers considerable potential for industrial applications including alcohols overproduction, flavor-quality control and developing new flavors. While how to regulate ehrlich and demethiolation pathways is still not applicable. Taking the conversion of methionine into methionol and methanethiol for example, we constructed two suppression subtractive cDNA libraries of Clonostachys rosea by using suppression subtractive hybridization (SSH) technology for screening regulators controlling the conversion. E3 ubiquitin-protein ligase gene HUWE1 screened from forward SSH library was validated to be related with the biosynthesis of end products. Overexpressing HUWE1 in C. rosea and S. cerevisiae significantly increased the biosynthesis of methanethiol and its derivatives in demethiolation pathway, while suppressed the biosynthesis of methional and methionol in ehrlich pathway. These results attained the directional regulation of both pathways by overexpressing HUWE1. Thus, HUWE1 has potential to be a key target for controlling and enhancing alcohols production by metabolic engineering.

Combinatorial optimization of CO2 transport and fixation to improve succinate production by promoter engineering.

To balance the flux of an engineered metabolic pathway to achieve high yield of target product is a major challenge in metabolic engineering. In previous work, the collaborative regulation of CO2 transport and fixation was investigated with co-overexpressing exogenous genes regulating both CO2 transport (sbtA and bicA) and PEP carboxylation (phosphoenolpyruvate (PEP) carboxylase (ppc) and carboxykinase (pck)) under trc promoter in Escherichia coli for succinate biosynthesis. For balancing metabolic flux to maximize succinate titer, a combinatorial optimization strategy to fine-tuning CO2 transport and fixation process was implemented by promoter engineering in this study. Firstly, based on the energy matrix a synthetic promoter library containing 20 rationally designed promoters with strengths ranging from 0.8% to 100% compared with the widely used trc promoter was generated. Evaluations of rfp and cat reporter genes provided evidence that the synthetic promoters were stably and had certain applicability. Secondly, four designed promoters with different strengths were used for combinatorial assembly of single CO2 transport gene (sbtA or bicA) and single CO2 fixation gene (ppc or pck) expression. Three combinations, such as Tang1519 (P4 -bicA + pP19 -pck), Tang1522 (P4 -sbtA + P4 -ppc), Tang1523 (P4 -sbtA + P17 -ppc) with a more than 10% increase in succinate production were screened in bioreactor. Finally, based on the above results, co-expression of the four transport and fixation genes were further investigated. Co-expression of sbtA, bicA, and ppc with weak promoter P4 and pck with strong promoter P19 (AFP111/pT-P4 -bicA-P4 -sbtA + pACYC-P19 -pck-P4 -ppc) provided the best succinate production among all the combinations. The highest succinate production of 89.4 g/L was 37.5% higher than that obtained with empty vector control. This work significantly enhanced succinate production through combinatorial optimization of CO2 transport and fixation. The promoter engineering and combinatorial optimization strategies used herein represents a powerful approach to tailor-making metabolic pathways for the production of other industrially important chemicals. Biotechnol. Bioeng. 2016;113: 1531-1541. © 2016 Wiley Periodicals, Inc.

miR-141 suppresses proliferation and motility of gastric cancer cells by targeting HDGF.

miR-141 belongs to the miR-200 family, and has been found to be associated with numerous human malignancies; however, its role in gastric cancer (GC) has not been examined in detail. Here, we validated that miR-141 was decreased in GC tissues and cell lines. Forced expression of miR-141 significantly repressed GC cell proliferation and colony formation. Furthermore, miR-141 suppressed in vitro migration and invasion of GC cells. Hepatoma-derived growth factor (HDGF) was confirmed to be a direct target of miR-141 in GC cells. The suppressive effects of miR-141 on GC cell proliferation, colony formation, in vitro migration, and invasion were partially mediated by suppressing HDGF expression. Moreover, the expression of HDGF was negatively correlated with miR-141 in GC tissues. Our data suggest that miR-141 might be associated and plays essential role in GC progression.