Environmental viromes reveal global virosphere of deep-sea sediment RNA viruses.

INTRODUCTION: Viruses are the most abundant and diverse life forms on the earth. Both DNA viruses and RNA viruses play important roles in marine ecosystems via regulating biogeochemical cycles. OBJECTIVES: However, the virome of marine RNA viruses has been rarely explored so far. In this study, therefore, the environmental viromes of deep-sea sediment RNA viruses were characterized on a global scale to reveal the global virosphere of deep-sea RNA viruses. METHODS: The viral particles were purified from each of 133 deep-sea sediment samples and then characterized based on metagenomes of RNA viruses. RESULTS: In this study, we established the global virome dataset of deep-sea RNA viruses purified from 133 sediment samples that were collected from typical deep-sea ecosystems of three oceans. A total of 85,059 viral operational taxonomic units (vOTUs) were identified, of which only 1.72% were hitherto known, indicating that the deep-sea sediment is a repository of novel RNA viruses. These vOTUs were classified into 20 viral families, including prokaryotic (7.09%) and eukaryotic (65.81%) RNA viruses. Furthermore, 1,463 deep-sea RNA viruses with complete genomes were obtained. The differentiation of RNA viral communities was driven by the deep-sea ecosystems as opposed to geographical region. Specifically, the virus-encoded metabolic genes took great effects on the differentiation of RNA viral communities by mediating the energy metabolism in the deep-sea ecosystems. CONCLUSIONS: Therefore, our findings indicate that the deep sea is a vast reservoir of novel RNA viruses for the first time, and the differentiation of RNA viral communities is driven by the deep-sea ecosystems through energy metabolism.

miRNA in food simultaneously controls animal viral disease and human tumorigenesis.

During virus infection in animals, the virus completes its life cycle in a host cell. A virus infection results in the metabolic deregulation of its host and leads to metabolic disorders, ultimately paving the way for cancer progression. Because metabolic disorders in virus infections occurring in animal are similar to metabolic disorders in human tumorigenesis, animal antiviral microRNAs (miRNAs), which maintain the metabolic homeostasis of animal cells, in essence, may have anti-tumor activity in humans. However, that issue has not been investigated. In this study, shrimp miR-34, a potential antiviral miRNA of shrimp against white spot syndrome virus (WSSV) infection, was identified. Overexpression of shrimp miR-34 in shrimp fed bacteria expressing miR-34 suppressed WSSV infection by targeting the viral wsv330 and wsv359 genes. Furthermore, the expression of shrimp miR-34 in mice fed miR-34-overexpressing shrimp suppressed breast cancer progression by targeting human CCND1, CDK6, CCNE2, E2F3, FOSL1, and MET genes. Therefore, our study suggests that the miRNAs in food could be an effective strategy for synchronously controlling viral diseases of economic animals and cancers in humans.

Electrochemical detection of miRNA-100 in the sera of gastric cancer patients based on DSN-assisted amplification.

Gastric cancer (GC) is a common malignant digestive tract tumor that leads to high mortality worldwide. Early diagnosis of GC is very important for adequate treatment. However, a rapid, specific and sensitive method for the detection of GC is currently not available. Here, a biosensor CPs/AuNP-AuE, the gold nanoparticle (AuNP)-modified Au electrode (AuE) which was coupled with DNA capture probes (CPs), was developed to detect the content of miR-100 in the sera of GC patients. The results showed that AuNPs were uniformly deposited on the surface of AuE. AuNPs enhanced the electrical conductivity and improved the effective area of AuE. CPs were successfully assembled on AuNP-AuE that could be digested by duplex-specific nuclease (DSN) from the miR-100/CPs complex on the electrode, improving the sensitivity of the biosensor by recycling miR-100. The data revealed that the biosensor was highly specific for the detection of miR-100, which had the ability to distinguish one base-pair mistake in miR-100. The detection of the biosensor for miR-100 ranged from 100 aM to 10 pM and the limit of detection (LOD) was estimated to be 100 aM. The detection results of 100 human sera samples using this biosensor indicated that the cutoff for the detection of gastric cancer was 5 fM. Therefore the biosensor developed in our study served as a rapid, specific and sensitive strategy for the detection of gastric cancer in clinic.

Requirement of splicing factor hnRNP A2B1 for tumorigenesis of melanoma stem cells.

BACKGROUND: Cancer stem cells play essential roles in tumorigenesis, thus forming an important target for tumor therapy. The hnRNP family proteins are important splicing factors that have been found to be associated with tumor progression. However, the influence of hnRNPs on cancer stem cells has not been extensively explored. METHODS: Quantitative real-time PCR and Western blot were used to examine gene expressions. RNA immunoprecipitation assays were conducted to identify the RNAs interacted with hnRNP A2B1. The in vivo assays were performed in nude mice. RESULTS: In this study, the results showed that out of 19 evaluated hnRNPs, hnRNP A2B1 was significantly upregulated in melanoma stem cells compared with non-stem cells, suggesting an important role of hnRNP A2B1 in cancer stem cells. Silencing of hnRNP A2B1 triggered cell cycle arrest in G2 phase, leading to apoptosis of melanoma stem cells. The results also revealed that hnRNP A2B1 could bind to the precursor mRNAs of pro-apoptosis genes (DAPK1, SYT7, and RNF128) and anti-apoptosis genes (EIF3H, TPPP3, and DOCK2) to regulate the splicing of these 6 genes, thus promoting the expressions of anti-apoptosis genes and suppressing the expressions of pro-apoptosis genes. The in vivo data indicated that hnRNP A2B1 was required for tumorigenesis by affecting the splicing of TPPP3, DOCK2, EIF3H, RNF128, DAPK1, and SYT7, thus suppressing apoptosis of melanoma stem cells. CONCLUSION: Our findings showed the requirement of hnRNP A2B1 for tumorigenesis, thus presenting novel molecular insights into the role of hnRNPs in cancer stem cells.

LncRNA LHFPL3-AS1 contributes to tumorigenesis of melanoma stem cells via the miR-181a-5p/BCL2 pathway.

Long noncoding RNAs (lncRNAs) are recognized as a new area for cancer therapy. B-cell lymphoma-2 (Bcl-2)-mediated suppression of apoptosis is an important molecular hallmark of cancer. However, the influence of lncRNA on the regulation of oncogenic Bcl-2 in cancer stem cells has not been explored. In this study, our findings revealed that the lncRNA LHFPL3-AS1-long, generated from the polypyrimidine tract binding protein 1 (PTBP1)-mediated splicing of the LHFPL3-AS1 precursor, upregulated BCL2 protein to contribute to tumorigenesis of melanoma stem cells. The in vitro and in vivo results showed that LHFPL3-AS1-long directly interacted with miR-181a-5p to inhibit the mRNA degradation of Bcl-2 (the target of miR-181), thus suppressing apoptosis of melanoma stem cells. The splicing factor PTBP1 regulated the alternative splicing of LHFPL3-AS1 transcript by preferentially binding to the motifs located in exon3 of LHFPL3-AS1 precursor, leading to the biogenesis of LHFPL3-AS1-long in melanoma stem cells. In patients with melanoma, the expressions of PTBP1 and LHFPL3-AS1 were significantly upregulated compared with the healthy donors. Therefore, our study revealed a mechanistic crosstalk among an onco-splicing factor, lncRNA and tumorigenesis of melanoma stem cells, enabling PTBP1 and LHFPL3-AS1 to serve as the attractive therapeutic targets for melanoma.

The novel peptides ICRD and LCGEC screened from tuna roe show antioxidative activity via Keap1/Nrf2-ARE pathway regulation and gut microbiota modulation.

In this study, a high-throughput strategy combined with MALDI TOF/TOF-MS and Discovery Studio 2017 was developed to screen peptides with certain functions from hydrolysate. Two dominant peptides, Ile-Cys-Arg-Asp (ICRD) and Leu-Cys-Gly-Glu-Cys (LCGEC), were predicted to have antioxidant activity by Discovery Studio 2017. Then the activity in vitro of peptides had been confirmed via DPPH assay. Both two peptides decreased apoptosis induced by UVB treatment in HaCaT cells and altered Keap1/Nrf2-ARE pathway transcription. Furthermore, the antioxidant activity of LCGEC was achieved after 6-week treatment in mice via regulating the Keap1/Nrf2-ARE pathway, inhibiting the release of proinflammatory cytokines, increasing the abundance of 3-indolepropionic acid and short-chain fatty acids production in feces and modulating gut microbiota composition. This study provided two tuna roe peptides with in vitro and in vivo antioxidant activity.

Protective effects of tuna meat oligopeptides (TMOP) supplementation on hyperuricemia and associated renal inflammation mediated by gut microbiota.

Recently, interest in using whole food-derived mixtures to alleviate chronic metabolic syndrome through potential synergistic interactions among different components is increasing. In this study, the effects and mechanisms of tuna meat oligopeptides (TMOP) on hyperuricemia and associated renal inflammation were investigated in mice. Dietary administration of TMOP alleviated hyperuricemia and renal inflammation phenotypes, reprogramed uric acid metabolism pathways, inhibited the activation of NLRP3 inflammasome and TLR4/MyD88/NF-κB signaling pathways, and suppressed the phosphorylation of p65-NF-κB. In addition, TMOP treatments repaired the intestinal epithelial barrier, reversed the gut microbiota dysbiosis and increased the production of short-chain fatty acids. Moreover, the antihyperuricemia effects of TMOP were transmissible by transplanting the fecal microbiota from TMOP-treated mice, indicating that the protective effects were at least partially mediated by the gut microbiota. Thus, for the first time, we clarify the potential effects of TMOP as a whole food derived ingredient on alleviating hyperuricemia and renal inflammation in mice, and additional efforts are needed to confirm the beneficial effects of TMOP on humans.

Comparisons of protective effects between two sea cucumber hydrolysates against diet induced hyperuricemia and renal inflammation in mice.

Hyperuricemia is an important risk factor for many diseases including hypertension and type 2 diabetes. This study investigated and compared the effects of hydrolysates of two sea cucumber species, Apostichopus japonicus and Acaudina leucoprocta, on the alleviation of diet-induced hyperuricemia and renal inflammation. The structure and abundance of oligopeptides in enzymatic hydrolysates of A. japonicus (EH-JAP) and A. leucoprocta (EH-LEU) were identified via MALDI-TOF/TOF-MS, and the anti-hyperuricemic and anti-inflammatory effects of the hydrolysates were explored in a diet-induced hyperuricemic mouse model. Both EH-JAP and EH-LEU inhibit uric acid biosynthesis and promote uric acid excretion, leading to the alleviation of the hyperuricemic phenotype. In addition, these two treatments down-regulated the transcription of pro-inflammatory cytokines, up-regulated the transcription of anti-inflammatory cytokines, and inhibited the activation of the Toll-like receptor 4/myeloid differentiation factor 88/NF-kappaB (TLR4/MyD88/NF-κB) signaling pathway, leading to the alleviation of renal inflammation. EH-JAP had better effects than EH-LEU due to differences in their regulation of uric acid biosynthesis, uric acid excretion and release of anti-inflammatory cytokines. In addition, EH-JAP and EH-LEU treatment alleviated the dysfunction of the gut microbiota by increasing the abundance of beneficial Lactobacillus and short-chain fatty acid producers and decreasing the abundance of opportunistic pathogens. This study provides a valuable reference for the development of sea cucumber applications.

Sulfated polysaccharides from Phaeodactylum tricornutum: isolation, structural characteristics, and inhibiting HepG2 growth activity in vitro.

Microalgae, eukaryotic unicellular plants, are increasing in demand due to their use as nutraceutical and food supplements. They consisted different kinds of biologically active components such as polysaccharides. On the other hand, cancer is the leading cause of death globally. At present, there is no efficient method to cure it. Therefore, in this work, we extracted polysaccharides from Phaeodactylum tricornutum (PTP), characterized the chemical composition and structure, and investigated its anticancer activity on HepG2 cells. The results showed that PTP was a sulfated polysaccharide with a high Mw of 4,810 kDa, and xylose, fucose, glucose and galactose were the main monosaccharides. PTP has significant anticancer activity in a dose-dependent manner (up to 60.37% at 250 ug/mL) according to MTT assays. Furthermore, cycle analysis was carried out to explain its anticancer activity. The results showed that it exhibited anticancer effect mainly through the induction of apoptosis without affecting the cycle and mitosis of HepG2 cells. This might make it a potential drug for anticancer treatment in the future.

In silico analysis and in vivo tests of the tuna dark muscle hydrolysate anti-oxidation effect.

Hydrolysate is a mixture of various peptides with specific functions. However, functional identification of hydrolysate with high throughput is still a difficult task. Furthermore, using in vivo tests via animal or cell experiments is time and labor-intensive. In this study, the peptides component of hydrolysate derived from the tuna dark muscle was measured via MALDI-TOF/TOF-MS, and the functions of the KEFT (Lys-Glu-Phe-Thr), EEASA (Glu-Glu-Ala-Ser-Ala) and RYDD (Arg-Tyr-Asp-Asp) peptides, which were found with the highest proportion, were predicted via Discovery Studio 2016 software. All three peptides were predicted to bind to the Keap1 protein with the highest fit-value and to affect the activity of Keap1, which is involved in anti-oxidation pathways. Subsequently, mice experiments showed that administration of tuna dark muscle hydrolysate increased the levels of superoxide dismutase and glutathione peroxidase in the serum and liver (P < 0.05) and decreased the malondialdehyde level (P < 0.05) as well as transcription of Keap1 (P > 0.05), which are consistent with the in silico analysis results using Discovery Studio 2016 software. The combination of in silico analysis and in vivo tests provided an alternative strategy for identifying hydrolysate function and provided insight into high-value utilization of protein hydrolysate.