N6-methyladenosine methylation on FSCN1 mediated by METTL14/IGF2BP3 contributes to human papillomavirus type 16-infected cervical squamous cell carcinoma.

Human papillomavirus (HPV) infection has been reported to be associated with N6-methyladenosine (m6A) modification in cancers. However, the underlying mechanism by which m6A methylation participates in HPV-related cervical squamous cell carcinoma (CSCC) remains largely unclear. In this study, we observed that m6A regulators methyltransferase like protein (METTL14) and insulin like growth factor 2 mRNA binding protein 3 (IGF2BP3) were upregulated in HPV-positive CSCC tissues and cell lines, and their high expression predicted poor prognosis for HPV-infected CSCC patients. Cellular functional experiments verified that HPV16 oncogenes E6/E7 upregulated the expression of METTL14 and IGF2BP3 to promote cell proliferation and epithelial mesenchymal transition of CSCC cells. Next, we found that E6/E7 stabilized fascin actin-bundling protein 1 (FSCN1) mRNA and elevated FSCN1 expression in CSCC cells through upregulating METTL14/IGF2BP3-mediated m6A modification, and FSCN1 expression was also validated to be positively associated with worse outcomes of HPV-positive CSCC patients. Finally, HPV16-positive CSCC cell lines SiHa and CaSki were transfected with knockdown vector for E6/E7 or METTL14/IGF2BP3 and overexpressing vector for FSCN1, and functional verification experiments were performed through using MTT assay, flow cytometry, wound healing assay and tumour formation assay. Results indicated that knockdown of E6/E7 or METTL14/IGF2BP3 suppressed cell proliferation, migration and tumorigenesis, and accelerated cell apoptosis of HPV-positive CSCC cells. Their tumour-suppressive effects were abolished through overexpressing FSCN1. Overall, HPV E6/E7 advanced CSCC development through upregulating METTL14/IGF2BP3-mediated FSCN1 m6A modification.

Curcumin-Loaded Bamboo Shoot Cellulose Nanofibers: Characterization and In Vitro Studies.

Given its high biological and pharmacological activities, curcumin (CUR) offers promising applications in functional foods. However, its low stability and bioavailability have greatly hindered its application in the food industry. The present study prepared cellulose nanofiber (CNF) from bamboo shoot processing byproducts and investigated its potential as a low-cost carrier. Our results showed that CUR was immobilized on CNF surfaces mainly through hydrogen bonding and eventually encapsulated in CNF matrices, forming a CNF-CUR complex with an encapsulation efficiency of 88.34% and a loading capacity of 67.95%. The CUR encapsulated in the complex showed improved stability after thermal and UV light treatments. Moreover, a slow and extended release pattern of CUR in a simulated gastrointestinal tract was observed, which could be appropriately described using the Korsmeyer-Peppas model. These results revealed that CNF is a promising protective carrier for the slow release of CUR, making it a better candidate for functional foods.

Structural characterization of a soluble polysaccharide SSPS1 from soy whey and its immunoregulatory activity in macrophages.

A soluble soybean polysaccharide SSPS1 with a molecular weight of 2737 kDa was extracted and purified from soy whey. SSPS1 was composed of glucose (97.3 %) and a small amount of mannose (2.7 %). Structural analysis results suggested that SSPS1 had a â†’ 6)-α-d-Glcp-(1 â†’ glucan structure, with a trace amount of α-d-Glcp-(1 â†’ connected to the main chain via O-3. In vitro immunological experiments suggested that SSPS1 enhanced the growth rate and phagocytic activity of RAW 264.7 macrophages. In addition, SSPS1 stimulated the secretion of cytokines (TNF-α, INF-ß, IL-6 and IL-1ß) as well as nitric oxide (NO) production through upregulating the expression of the related genes and proteins in RAW 264.7 cells. This study provided a new method for efficient utilization of soy whey, and the results indicate that SSPS1 extracted from soy whey could be used as a novel immunomodulator.

Bamboo shavings derived O-acetylated xylan alleviates loperamide-induced constipation in mice.

BSH-1 is an O-acetylated xylan obtained from bamboo shavings. This study determined the protective effects of BSH-1 against loperamide (Lop)-induced constipation in mice. Mice received BSH-1 by gavage daily for 14 days. In constipated mice, BSH-1 significantly shortened the defecation time and raised the gastrointestinal (GI) transit rate, stool production, and cecal concentration of short-chain fatty acids (SCFAs). BSH-1 regulated the serum levels of gut hormones and neurotransmitters. BSH-1 also significantly altered the cecal microbiota of the constipated mice by increasing the abundance of potentially beneficial bacteria (e.g., Lactobacillus, Roseburia, and Bacteroidales_S24-7) and decreasing potentially pathogenic bacteria (e.g., Alloprevotella and Staphylococcus). Furthermore, colonic transcriptome analysis revealed that BSH-1 significantly reversed the expression changes of genes related to intestinal motility, water and ion transport, inflammation and cancer in constipated mice. Our findings indicated that BSH-1 effectively relieved Lop-induced constipation in mice and could be potentially used for constipation treatment.

Selenium enrichment improves anti-proliferative effect of oolong tea extract on human hepatoma HuH-7 cells.

Selenium (Se)-enriched tea is attracting increasing interests due to its significantly improved health benefits. This study was to investigate the anti-proliferative effects of Se-enriched oolong tea against human hepatoma HuH-7 cells. Compared with regular oolong tea extract (TE, 0.04 µg selenium/g), Se-enriched oolong tea extract (Se-TE, 0.51 µg selenium/g) exhibited more prominent anti-proliferative effect against HuH-7 cells with an IC50 of 203.1 µg/mL, mainly due to the synergistic effects of organic selenium and tea polyphenols. Our results found that Se-TE increased intracellular ROS production, arrested the cell cycle at G2/M phase, and thus induced cell apoptosis. In addition, western blotting assay revealed the increased expressions of the p53, Bax, caspase 3, and a reduction of Bcl-2 and CDK2, resulting in Se-TE-induced apoptosis. The improved anti-proliferative effect makes Se-enriched oolong tea extract a promising health-promoting ingredient in food industry.

Pediococcus pentosaceus B49 from human colostrum ameliorates constipation in mice.

Constipation is a prevalent and burdensome gastrointestinal (GI) disorder that seriously affects the quality of human life. This study evaluated the effects of the P. pentosaceus B49 (from human colostrum) on loperamide (Lop)-induced constipation in mice. Mice were given P. pentosaceus B49 (5 × 109 CFU or 5 × 1010 CFU) by gavage daily for 14 days. The result shows that P. pentosaceus B49 treatment relieved constipation in mice by shortening the defecation time, increasing the GI transit rate and stool production. Compared with the constipation control group, the P. pentosaceus B49-treated groups showed decreased serum levels of inhibitory neurotransmitters (vasoactive intestinal peptide and nitric oxide), increased serum levels of excitatory neurotransmitters (acetylcholinesterase, motilin, and gastrin), and elevated cecal concentration of short chain fatty acids (SCFAs). Analysis of cecal microbiota reveals that P. pentosaceus B49 was colonized in the intestine of constipated mice, and altered the cecal microbiota by increasing beneficial SCFAs-producing bacteria (i.e., Lactobacillus, Ruminococcaceae_UCG-014, and Bacteroidales_S24-7) and decreasing potential pathogenic bacteria (i.e., Staphylococcus and Helicobacter). Moreover, transcriptome analysis of the colon tissue shows that P. pentosaceus B49 partly normalized the expression of genes related to GI peristalsis (i.e., Ache, Chrm2, Slc18a3, Grp, and Vip), water and electrolyte absorption and transport (i.e., Aqp4, Aqp8, and Atp12a), while down-regulating the expression of pro-inflammatory and pro-oncogenic genes (i.e., Lbp, Lgals2, Bcl2, Bcl2l15, Gsdmc2, and Olfm4) in constipated mice. Our findings indicate that P. pentosaceus B49 effectively relieves constipation in mice and is a promising candidate for treating constipation.

Hypoglycemic effect of dietary fibers from bamboo shoot shell: An in vitro and in vivo study.

Bamboo shoot shell (BSS) was enzymatically decomposed to yield insoluble dietary fiber (IDF), soluble dietary fiber (SDF) and total dietary fiber (TDF), which were investigated for their hypoglycemic properties using in vitro and in vivo methods. The results indicated that SDF exhibited significantly higher glucose adsorbing capacity than those of IDF and TDF. Moreover, SDF showed similar inhibition potential against α-amylase with acarbose. TDF displayed the greater capacities of delaying glucose diffusion and inhibition of α-glucosidase than those of SDF. In the diabetic mice, after 4-week administration of BSS fibers or metformin, the blood glucose levels were significantly reduced and the oral glucose tolerance was improved. TDF and IDF hardly influenced the blood insulin level, while SDF could significantly increase blood insulin level. The results showed that BSS fibers could be a potentially available dietary ingredient in functional food.

Anti-inflammatory activity of polysaccharides from Phellinus linteus by regulating the NF-κB translocation in LPS-stimulated RAW264.7 macrophages.

Inflammatory response remains one of the most common and serious complications of disease. In order to profound understanding relationship between Phellinus linteus polysaccharides (TCM) and inflammation, inflammatory cell model was constructed by LPS acting RAW264.7 cell line. The results showed that TCM could decrease the pro-inflammatory cytokines (TNF-α, IL-1ß, IL-2, IL-6 and IL-12) contents and the mRNA expression levels and increase the anti-inflammatory cytokines (IL-4 and IL-10) contents and the mRNA expression levels. Additionally, the levels of NF-κB translocation was significantly decreased, which associated with the IκBα phosphorylation level decreased and the AMPKα phosphorylation level increased. These results indicated that TCM could reduce the inflammatory responses in the LPS induced inflammatory cell model might be related to inhibit NF-κB translocation and regulate the balance of anti-inflammatory and pro-inflammatory factors.

Functional characterization of a potent anti-tumor polysaccharide in a mouse model of gastric cancer.

AIMS: Natural polysaccharides are emerging as a new class of immunomodulatory agents due to their potent immunostimulatory effects and suitable biocompatibility. The aim of this study was to identify potent and selective anticancer activity of a bioactive polysaccharide. MATERIALS AND METHODS: In vitro, viability assay was performed to screen 16 of bioactive polysaccharides in a panel of normal and cancer cell lines. Foci formation, soft agar, BrdU incorporation, cell cycle analyses, and ß-galactosidase staining were performed to validate the screening results. In vivo, both murine gastric cancer syngeneic and a human gastric tumor xenografts models were applied. Tumor histology, immunohistochemical staining, cytokine array and flow cytometry analyses were assayed. KEY FINDINGS: BSP (bamboo shaving polysaccharides) was identified as the most selective polysaccharide for inhibiting the growth of six gastric cancer cell lines while having no toxic effect on normal gastric mucosal cells. Similarly, BSP had more potent killing effect on a subset of human stomach cancer cells than liver or lung cancer cells. In vivo, BSP significantly inhibited tumor growth and prolonged the survival of mice bearing a gastric tumor; these effects are mediated by tumor cell apoptosis and remodeling of the tumor microenvironment by boosting both immune cell subpopulations and cytokine production in murine gastric cancer syngeneic model. A significant decrease of F4/80-positive tumor-associated macrophages was also observed. SIGNIFICANCE: The findings of this study suggest that the potent and selective anti-tumor activity of bioactive polysaccharides such as BSP warrants clinical testing for the treatment of gastric cancer.

In vitro fermentation of O­acetyl­arabinoxylan from bamboo shavings by human colonic microbiota.

BSH-1 is an O­acetyl-arabinoxylan obtained from bamboo shavings. This study investigated its fermentation behavior by human colonic microbiota in vitro. Results showed that BSH-1 remarkably modulated the composition of human colonic microbiota, mainly by increasing the growth of potential beneficial genera (i.e. Bifidobacterium, Lactobacillus, Bacteroides, Prevotella_7, Parabacteroides) and by decreasing the growth of potential harmful genera (i.e. Fusobacterium, Lachnospiraceae_UCG-008, Bilophila and Desulfovibrio). BSH-1 significantly promoted the production of short-chain fatty acids, especially acetic, propionic and n-butyric acids. After 48 h fermentation, the concentration of n-butyric acid in BSH-1 fermentation culture was increased by 2.41 times compared to the blank. During fermentation, the activity of acetyl xylan esterase, arabinofuranosidase, xylanase and xylosidase was enhanced. Moreover, free arabinose, xylose, xylobiose, xylotriose, xylotetraose, xylopentaose and xylohexaose were detected. These results suggest that BSH-1 could potentially be a functional ingredient to improve gut health.

Expression, purification and molecular characterization of a novel endoglucanase protein from Bacillus subtilis SB13.

Bacillus subtilis strain SB13 which is isolated in our previous work was confirmed to produce endoglucanase. In this study, a novel endoglucanase gene (accession number: KX576676) was identified and cloned from SB13. Compared with other consensus sequence of reported endoglucanase genes in the GenBank database, this gene displays five differences (including T740C,A874G,A983G, T1210G and T1301C), which leading to five amino acid changes. Homology modeling has indicated that these five changes were located in the α-helix and random coil regions of the glycosyl hydrolase family 5 (GH5) domain, the random coil and ß-sandwich of the type 3 carbohydrate-binding module (CBM3) domain, and the random coil domain. Aprokaryotic expression vector pET30a-endoglucanase was constructed and the endoglucanase was induced to express. The expressed endoglucanase was confirmed by liquid chromatography-tandem mass spectrometry (LC-MSMS) and detected via reaction with carboxymethyl cellulose. In order to obtain the highest expression level of endoglucanase, the expression conditions including IPTG concentration, temperature and pH were optimized. The recombinant endoglucanase protein was purified using a Ni-NTA column, and the 6 × His-tag was removed with thrombin. The results showed that both the modified and unmodified purified endoglucanase had high activity (7.65 ± 0.35 U and 15.05 ± 1.81 U, respectively), thus demonstrating the potential use of this enzyme in various industrial applications. The substitutions of L247P,N292D, F404V and L434P might contribute to the activity of the endoglucanase, and the insertion of a 6 × His-tag at the N-terminal of the endoglucanase might also affect its activity.

Structural Characterization and Antifatigue Effect In Vivo of Maca (Lepidium meyenii Walp) Polysaccharide.

Maca (Lepidium meyenii Walp) polysaccharides (MP) with purity of 99.2% were obtained to investigate their structural characteristics and antifatigue effect in vivo. The physicochemical properties of MP were analyzed through high-performance gel filtration chromatography, IR, monosaccharide composition, methylation, GC-MS, and NMR analyses. The antifatigue effect of MP was evaluated by using a mouse weight-loaded swimming model. MP is an acidic heteropolysaccharide with an average molecular weight (Mw ) of 793.5 kDa. It is composed of D-GalA: D-Glc: L-Ara: D-Man: D-Gal: L-Rha = 35.07:29.98:16.98:13.01:4.21:0.75 (mol, %). The findings revealed that MP contained ß-1,3-Galp(A), ß-1,3-Glcp, and α-1, 3-Manp linked alternatingly to form a backbone (5:4:1). MP (above mid-dosage 50 mg/kg bw/d) could effectively elongate swimming durations and accelerate average swimming speeds (within the 1st 5 min) of mice (P < 0.05) and improve the serous biochemical parameters of mice. Compared with the control model, high-dosage (100 mg/kg bw/d) MP treatment could significantly enhance glutathione peroxidase and creatine kinase activities (P < 0.05) and decreased lactate dehydrogenase activity (P < 0.01). High-dosage MP could significantly reduce the levels of blood urea nitrogen, lactic acid, and malondialdehyde (P < 0.05). MP is an acidic polysaccharide with a high D-GalA content, which could be responsible for the antifatigue effect of maca.

Isolation, chemical characterization, and immunomodulatory activity of naturally acetylated hemicelluloses from bamboo shavings.

Bamboo shavings, the outer or intermediate layer of bamboo stems, are the bulk of by-products produced in bamboo processing. In this study we investigated the isolation, chemical characterization, and immunostimulatory activity in vitro of the hemicelluloses from bamboo shavings. Shavings were first pretreated by steam explosion. The optimal pretreatment was found to be steam explosion at 2.2 MPa for 1 min. Following this pretreatment, the yield of hemicelluloses reached (2.05±0.22)% (based on the dry dewaxed raw materials), which was 5.7-fold higher than that of untreated samples. Bamboo-shavings hemicellulose (BSH) was then prepared by hot water extraction and ethanol precipitation from the steam-exploded shavings. Purification of BSH by anion-exchange chromatography of diethylaminoethanol (DEAE)-sepharose Fast Flow resulted in a neutral fraction (BSH-1, purity of 95.3%, yield of 1.06%) and an acidic fraction (BSH-2, purity of 92.5%, yield of 0.79%). The weight-average molecular weights (Mw) of BSH-1 and BSH-2 were 12 800 and 11 300 g/mol, respectively. Chemical and structural analyses by Fourier transform infrared spectroscopy (FT-IR), 1D (1H and 13C) and 2D (heteronuclear single quantum correlation (HSQC)) nuclear magnetic resonance (NMR) spectra revealed that BSH-1 was O-acetylated-arabinoxylan and BSH-2 was O-acetylated-(4-O-methylglucurono)-arabinoxylan. BSH-1 had a higher content of acetyl groups than BSH-2. For the immunomodulatory activity in vitro, BSH and BSH-2 significantly stimulated mouse splenocyte proliferation while BSH-1 had no effect; BSH, BSH-1, and BSH-2 markedly enhanced the phagocytosis activity and nitric oxide production of the murine macrophage RAW264.7 in a dose-dependent manner. Our results suggest that the water-extractable hemicelluloses from steam-exploded bamboo shavings are naturally acetylated and have immunostimulatory activity.