Identification and characterization of ι-carrageenase from macroalgae-associated bacterium Microbulbifer sp. YNDZ01.

BACKGROUND: In the present study, the ι-carrageenase gene, Car1293, was obtained from the genome of Microbulbifer sp. YNDZ01, which was isolated from the surface of macroalgae. To date, there are few studies on ι-carrageenase and the anti-inflammatory activity of ι-carrageenan oligosaccharides (CGOS). To enhance our perspective on ι-carrageenase and ι-carrageen oligosaccharides, the sequence, protein structure, enzymatic properties, enzymatic digestion products and anti-inflammatory activity of the gene were investigated. RESULTS: The gene length of Car1293 is 2,589 bp, encoding an enzyme with 862 amino acids, which shares 34% similarity with any previously reported ι-carrageenase. The spatial structure of Car1293 consists of many α-helices with a ß-fold binding module located at its terminus, and eight binding sites were found in the binding module as a result of docking with CGOS-DP4 ligand. The optimum temperature and pH for the activity of recombinant Car1293 toward ι-carrageenan were 50 °C and 6.0, respectively. The hydrolysates of Car1293 are mainly degree of polymerization (DP)8, with minor products showing DP2, DP4, and DP6. The enzymatic hydrolysates CGOS-DP8 showed prominent anti-inflammatory activity, which was greater than that of the positive control l-monomethylarginine in lipopolysaccharide-induced RAW264.7 macrophages. It inhibited nitric oxide production, as well as significantly inhibited tumor necrosis factor-α and interleukin-6 secretion. CONCLUSION: The ι-carrageenase sequence encoded by Car1293 is novel and can hydrolyze carrageenan into CGOS-DP8 that has a significant anti-inflammatory effect. The present study fills a gap in the research on the biological activity of oligosaccharides in ι-carrageenan and provides promising data for the development of natural anti-inflammatory agent. © 2023 Society of Chemical Industry.

Complete genome sequence of the denitrifying Pseudomonas sp. strain DNDY-54 isolated from deep-sea sediment of ninety east ridge.

Pseudomonas sp. strain DNDY-54, a denitrifying bacterium, was isolated from a deep-sea sediment sample from Ninety East Ridge in the Indian Ocean. Here, we show that the complete genome of DNDY-54 has one circular chromosome of 4,412,895 bp with mean 60.57% GC content. The complete genome contains 4111 predicted protein-coding genes, 59 tRNAs, and 4 rRNA operons as 16S-23S-5S rRNA. On the basis of the annotation results, we identified genes that encode 27 proteins related to nitrogen metabolism, including enzymes that make up a complete denitrifying pathway. This work will improve the understanding of nitrogen cycling in the deep biosphere and provides a new candidate for protection of the environment and applications in waste water disposal.

Mannose Treatment: A Promising Novel Strategy to Suppress Inflammation.

High glucose and fructose intake have been proven to display pro-inflammatory roles during the progression of inflammatory diseases. However, mannose has been shown to be a special type of hexose that has immune regulatory functions. In this review, we trace the discovery process of the regulatory functions of mannose and summarize some past and recent studies showing the therapeutic functions of mannose in inflammatory diseases. We conclude that treatment with mannose can suppress inflammation by inducing regulatory T cells, suppressing effector T cells and inflammatory macrophages, and increasing anti-inflammatory gut microbiome. By summarizing all the important findings, we highlight that mannose treatment is a safe and promising novel strategy to suppress inflammatory diseases, including autoimmune disease and allergic disease.

Overexpression of circ_0021093 circular RNA forecasts an unfavorable prognosis and facilitates cell progression by targeting the miR-766-3p/MTA3 pathway in hepatocellular carcinoma.

Increasing studies have demonstrated the important roles of circular RNAs (circRNAs) in human malignancies. Nevertheless, the molecular mechanisms and functions of circRNAs in hepatocellular carcinoma (HCC) are still not fully understood. In the present study, we evaluated circ_0021093 expression in 82 pairs of HCC tissues and 5 cell lines by qRT-PCR. The clinical implications of circ_0021093 were evaluated. In addition, the viability, apoptosis, migration and invasion capacities of different HCC cells were evaluated by gain-/loss-of-function experiments. Target prediction and dual-luciferase reporter experiments were performed to identify the molecular mechanisms of circ_0021093. Upregulation of circ_0021093 was found in HCC tumor samples and cells. Additionally, upregulated circ_0021093 was related to adverse clinical characteristics and an unfavorable prognosis. Furthermore, downregulated circ_0021093 attenuated cell growth, migration and invasion but increased cell apoptosis. By contrast, ectopically expressed circ_0021093 enhanced the abovementioned malignant biological behaviors. For mechanism exploration, circ_0021093 sponges of miR-766-3p were used in HCC cells. In addition, we found that metastasis-associated protein 3 (MTA3) was a direct target of miR-766-3p and that the oncogenic function of circ_0021093 was partly dependent on the miR-766-3p/MTA3 axis according to rescue assays. In conclusion, the circ_0021093/miR-766-3p/MTA3 regulatory axis may be an effective therapeutic target for HCC.

Transcriptional regulation of Bcl-2 gene by the PR/SET domain family member PRDM10.

Bcl-2 (B-cell lymphoma 2) protein is localized in the outer membrane of mitochondria, where it plays an important role in promoting cellular survival and inhibiting the actions of pro-apoptotic proteins. PRDM10 is a member of the PR/SET family of epigenetic regulators and may play a role in development and cell differentiation. Here we show that human PRDM10 contributes to the transcriptional regulation of human Bcl-2 gene. We found that PRDM10-depletion in human cells reduced the expression of Bcl-2 protein and over-expression of PRDM10 promoted Bcl-2 protein expression. Furthermore, luciferase reporter activity of Bcl-2 gene P1 promoter was significantly increased in cells co-transfected with PRDM10, and PRDM10 was able to bind to the Bcl-2 P1 promoter in vivo. Using The Cancer Genome Atlas (TCGA) data set, we found weak positive correlation between PRDM10 and Bcl-2 in several cancer types including cancers of the breast, colon, and lung tissues. These data identify a novel function for PRDM10 protein and provide insights on the transcriptional control of Bcl-2 expression.