Taurine and proliferation of lymphocytes in physically restrained rats

Taurine metabolism is modulated in Vibrio-infected Penaeus vannamei to shape shrimp antibacterial response and survival

BACKGROUND

Numerous microorganisms are found in aquaculture ponds, including several pathogenic bacteria. Infection of cultured animals by these pathogens results in diseases and metabolic dysregulation. However, changes in the metabolic profiles that occur at different infection stages in the same ponds and how these metabolic changes can be modulated by exogenous metabolites in Penaeus vannamei remain unknown.

RESULTS

Here, we collected gastrointestinal tract (GIT) samples from healthy, diseased, and moribund P. vannamei in the same aquaculture pond for histological, metabolic, and transcriptome profiling. We found that diseased and moribund shrimp with empty GITs and atrophied hepatopancreas were mainly infected with Vibrio parahaemolyticus and Vibrio harveyi. Although significant dysregulation of crucial metabolites and their enzymes were observed in diseased and moribund shrimps, diseased shrimp expressed high levels of taurine and taurine metabolism-related enzymes, while moribund shrimp expressed high levels of hypoxanthine and related metabolism enzymes. Moreover, a strong negative correlation was observed between taurine levels and the relative abundance of V. parahaemolyticus and V. harveyi. Besides, exogenous taurine enhanced shrimp survival against V. parahaemolyticus challenge by increasing the expression of key taurine metabolism enzymes, mainly, cysteine dioxygenase (CDO) and cysteine sulfinic acid decarboxylase (CSD).

CONCLUSIONS

Our study revealed that taurine metabolism could be modulated by exogenous supplementation to improve crustacean immune response against pathogenic microbes. Video Abstract.

Metabolic profile of irradiated whole blood by chemical isotope-labeling liquid chromatography-mass spectrometry

Irradiated blood is a new type of blood product used to prevent transfusion-associated graft-versus-host disease. However, the effects of irradiation on the metabolism of plasma, red blood cells (RBCs), and peripheral blood mononuclear cells (PBMCs) are largely unknown. We developed a workflow for testing metabolic changes in whole blood to determine the impact of irradiation by chemical isotope labeling liquid chromatography-mass spectrometry (CIL LC-MS). Blood parameters, PBMC proliferation and apoptosis were examined before and after irradiation. Next, the amine/phenol metabolites in the blood components were assayed by ¹²C- and¹³C-dansylation labeling LC-MS. We identified 1654, 1730, and 1666 peak pairs in plasma, RBCs, and PBMCs, respectively. We screened out 367, 177, and 219 significant metabolites in plasma, RBCs, and PBMCs, respectively, by principle component analyses, volcano plots, and Venn plots. Metabolic pathway analyses showed that irradiation modulated taurine and hypotaurine metabolism in plasma and purine metabolism in RBCs and PBMCs. Changes in potential biomarkers, including an increase in hypoxanthine level and a decrease in adenine level, may be related to the dysfunction of DNA synthesis in PBMCs. The decreased AMP level in RBCs may interfere with RBC storage lesions. Our research provides a more comprehensive perspective on blood metabolism associated with irradiation.

Comparative metabolic profiles of total and partial body radiation exposure in mice using an untargeted metabolomics approach

INTRODUCTION

A large scale population exposure to ionizing radiation during intentional or unintentional nuclear accidents undoubtedly generates a complex scenario with partial-body as well as total-body irradiated victims. A high throughput technique based rapid assessment method is an urgent necessity for stratification of exposed subjects independent of whether exposure is uniform total-body or non-homogenous partial-body.

OBJECTIVE

Here, we used Nuclear Magnetic Resonance (NMR) based metabolomics approach to compare and identify candidate metabolites differentially expressed in total and partially irradiated mice model.

METHODS

C57BL/6 male mice (8-10 weeks) were irradiated total-body or locally to thoracic, hind limb or abdominal regions with 10 Gy of gamma radiation. Urine samples collected at 24 h post irradiation were examined using high resolution NMR spectroscopy and the datasets were analysed using multivariate analysis.

RESULTS

Multivariate and metabolic pathway analysis in urine samples collected at 24 h post-radiation exhibited segregation of all irradiated groups from controls. Metabolites associated with energy metabolism, gut flora metabolism and taurine were common to partial and total-body irradiation, thus making them potential candidates for radiation exposure. Nevertheless, a distinct metabolic pattern was observed in partial-body exposed groups with maximum changes observed in the hind limb region indicating differential tissue associated radiation sensitivity. The organ-specific changes may provide an early warning regarding the physiological system at risk after radiation injury.

CONCLUSION

The study affirms potentiality of metabolite markers and comparative analysis could be an important piece of information for an integrated solution to a complex research question in terms of radiation biomarkers.

Taurine Chloramine decreases cell viability and cytokine production in blood and spleen lymphocytes from septic rats

Taurine (Tau) is an abundant amino acid in polymorphonuclear leukocytes that react with hypochlorous acid to form taurine chloramine (TauCl) under inflammatory conditions. We investigated potential interactions between lymphocytes and TauCl in rats submitted to cecal ligation. Animals were divided into sham or CLP groups (24 or 120 h) to isolate lymphocytes from blood and spleen. Lymphocytes were cultured at a concentration of 1×106 cells/mL and activated by concanavalin A. Tau and TauCl were added at 1, 10, and 100 μM. Cells were incubated with MTT to evaluate cell viability and cytokine concentration in the supernatant was determined. TauCl decreased lymphocyte viability and altered the secretion pattern of important inflammatory mediators in non-specific-phenotype manner. The effort to a is elucidate mechanisms of immune cell (dys)function in sepsis is important to better understand the complex regulation of immune system during sepsis development, and further studies are necessary to confirm TauCl as potential target in this context.

Anti-tumor activity and immunogenicity of a succinoglycan riclin

Natural polysaccharides have attracted considerable interests due to diverse biological activities. Succinoglycan is an extracellular polysaccharide produced by most Agrobacterium strains. Here, we confirmed riclin was a typical succinoglycan by NMR and methylation analysis, and investigated the antitumor effects of riclin in sarcoma 180 tumor-bearing mice. The results showed that riclin inhibited the tumor growth significantly as well as cyclophosphamide (CTX). While CTX caused serious damage to spleen structure, riclin increased the spleen index and promoted lymphocytes proliferation in peripheral blood, spleen and lymph nodes. Riclin decreased splenocytes apoptosis as evidenced by alterations of B-cell lymphoma-2 family proteins and Cleaved Caspase-3 protein. Moreover, ¹H nuclear magnetic resonance (NMR)-based metabolomics analysis revealed that riclin partially altered the metabolic profiles of splenocytes. In conclusion, riclin is a succinoglycan that performed strong immunogenicity and suppressed sarcoma growth in mice. Succinoglycan riclin could be a potential antitumor agent for functional food and pharmaceutical purpose.

Metabolomic analysis reveals metabolic alterations of human peripheral blood lymphocytes by perfluorooctanoic acid

Perfluorooctanoic acid (PFOA) is a dispersive persistent organic pollutant in the environment. Accumulating reports suggest that PFOA is toxic to human lymphocytes; however, the toxicological effects of PFOA on these cells remain largely unclear. In this study, ultra-performance liquid chromatography (UPLC)-based metabolomic analysis was employed to identify metabolites in human peripheral blood lymphocytes and to assess the metabolic alterations caused by PFOA exposure. Our comparative metabolomic analysis results demonstrated that PFOA treatment could increase the level of organic acids and reduce the level of lipid molecules. Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation further highlighted the fact that the PFOA treatment interfered with the metabolism of amino acids, carbohydrates and lipids, which may lead to disruption of the immune system.

Effect of Taurine on Thymus Differentiation of Dex-Induced Immunosuppressive Mice

Taurine (2-aminoethanesulfonic acid) has positive effects on the formation of immune systems. In this study, we evaluated the effects of taurine on the development of T lymphocyte subpopulations in thymus of immunosuppresive mice. The immunosuppressed mice model was established by intraperitoneal injection of dexamethasone (Dex) for 7 days. Mice (male, Kunming strain) were randomly divided into three groups, the normal control group (Cont.), the Dex-induced immunosuppressive model group (Dex + PBS), and the taurine intervention group (Dex + TAU). Taurine was administered at a dose of 200 mg/kg for 30 days or until euthanasia. Total cell numbers in the thymi of mice were evaluated by cell count, and the flow cytometry was used to determine the proportion of different cell subsets. Our results showed that the size and weight of thymi of Dex + PBS group were significantly smaller than those of Cont. group, and taurine administration efficiently increased the thymus index. Taurine also significantly increased the number of CD4- CD8- double negative (DN), CD4+ CD8+ double positive (DP), CD4+ single positive (CD4+) and CD8+ SP (CD8+) cells compared with the Dex + PBS group, but did not affect the CD4+/CD8+ cell ratio in thymus of Dex-induced immunoseppressive mice. Our results suggested that taurine has a positive effect on thymus differentiation in Dex-induced immunosuppressive mice.

Compound image segmentation of published biomedical figures

Motivation

Images convey essential information in biomedical publications. As such, there is a growing interest within the bio-curation and the bio-databases communities, to store images within publications as evidence for biomedical processes and for experimental results. However, many of the images in biomedical publications are compound images consisting of multiple panels, where each individual panel potentially conveys a different type of information. Segmenting such images into constituent panels is an essential first step toward utilizing images.

Results

In this article, we develop a new compound image segmentation system, FigSplit, which is based on Connected Component Analysis. To overcome shortcomings typically manifested by existing methods, we develop a quality assessment step for evaluating and modifying segmentations. Two methods are proposed to re-segment the images if the initial segmentation is inaccurate. Experimental results show the effectiveness of our method compared with other methods.

Availability and implementation

The system is publicly available for use at: https://www.eecis.udel.edu/~compbio/FigSplit. The code is available upon request.

Contact

shatkay@udel.edu.

Supplementary information

Supplementary data are available online at Bioinformatics.

Effect of Radiation on the Expression of Taurine Transporter in the Intestine of Mouse

There has been a growing interest on the effects of radiation since the Fukushima nuclear power plant accident of 2011. Taurine has been reported to have a radioprotective effect in irradiated mice. However, the detailed mechanism of this radioprotective effect is still awaiting clarification. The aim of this study was to investigation how radiation affects the expression of taurine and to shed light on the mechanism accounting for radioprotective and radiation mitigating effect. Six-week-old male mice were randomly divided into two groups: IR group (7 Gy irradiation) and IR + Tau group (7 Gy irradiation + taurine 3000 mg/kg/day). We examined the survival rate, the expression of taurine and taurine transporter in the small intestine and the urinary taurine concentration. In this study, no statistically significant difference was found in the survival rate between IR Group and IR + Tau Group. Three days and 7 days after irradiation, the urinary taurine concentration of IR + Tau group increased more than that of IR group. Three days and 10 days after irradiation, the expression of taurine and taurine transporter in the small intestine of IR group and IR + Tau group decreased more than that of normal small intestine. It is reported that radiation exposure increases the urinary taurine concentration. We found that the radiation exposure decreases the expression of the taurine transporter in the small intestine of mouse. This finding suggests that a decrease in the expression of the taurine transporter promotes the release of taurine from the tissue into the urine.

Cancer associated fibroblasts have phenotypic and functional characteristics similar to the fibrocytes that represent a novel MDSC subset

Circulating fibrocytes were reported to represent a novel myeloid-derived suppressor cell (MDSC) subset and they were also proposed to be involved in the tumor immune escape. This novel fibrocyte subset had a surface phenotype resembling non-monocytic MDSCs (CD14^-CD11c^hiCD123^-) and exhibited immunomodulatory roles. Most effector functions of fibrocytes (circulating fibroblast-progenitors) are accomplished as tissue fibroblasts, likewise in the tumor microenvironment. Therefore, fibroblasts at tumor tissues should be evaluated whether they display similar molecular/gene expression patterns and functional roles to the blood-borne fibrocytes. A chemically induced rat breast carcinogenesis model was utilized to obtain cancer associated fibroblasts (CAFs). CAFs and normal tissue fibroblasts (NFs) were isolated from cancerous and healthy breast tissues, respectively, using a previously described enzymatic protocol. Both CAFs and NFs were analyzed for cell surface phenotypes by flow cytometry and for gene expression profiles by gene set enrichment analysis (GSEA). PBMCs were cocultured with either NFs or CAFs and proliferations of PBMCs were assessed by CFSE assays. Morphological analyses were performed by immunocytochemistry stainings with vimentin. CAFs were spindle shaped cells unlike their blood-borne counterparts. They did not express CD80 and their MHC-II expression was lower than NFs. Although CAFs expressed the myeloid marker CD11b/c, its expression was lower than that on the circulating fibrocytes. CAFs did not express granulocytic/neutrophilic markers and they seemed to have developed in an environment containing T_HELPER2-like cytokines. They also showed immunosuppressive effects similar to their blood-borne counterparts. In summary, CAFs showed similar phenotypic and functional characteristics to the circulating fibrocytes that were reported to represent a unique MDSC subset.

Radiation protection following nuclear power accidents: a survey of putative mechanisms involved in the radioprotective actions of taurine during and after radiation exposure

There are several animal experiments showing that high doses of ionizing radiation lead to strongly enhanced leakage of taurine from damaged cells into the extracellular fluid, followed by enhanced urinary excretion. This radiation-induced taurine depletion can itself have various harmful effects (as will also be the case when taurine depletion is due to other causes, such as alcohol abuse or cancer therapy with cytotoxic drugs), but taurine supplementation has been shown to have radioprotective effects apparently going beyond what might be expected just as a consequence of correcting the harmful consequences of taurine deficiency per se. The mechanisms accounting for the radioprotective effects of taurine are, however, very incompletely understood. In this article an attempt is made to survey various mechanisms that potentially might be involved as parts of the explanation for the overall beneficial effect of high levels of taurine that has been found in experiments with animals or isolated cells exposed to high doses of ionizing radiation. It is proposed that taurine may have radioprotective effects by a combination of several mechanisms: (1) during the exposure to ionizing radiation by functioning as an antioxidant, but perhaps more because it counteracts the prooxidant catalytic effect of iron rather than functioning as an important scavenger of harmful molecules itself, (2) after the ionizing radiation exposure by helping to reduce the intensity of the post-traumatic inflammatory response, and thus reducing the extent of tissue damage that develops because of severe inflammation rather than as a direct effect of the ionizing radiation per se, (3) by functioning as a growth factor helping to enhance the growth rate of leukocytes and leukocyte progenitor cells and perhaps also of other rapidly proliferating cell types, such as enterocyte progenitor cells, which may be important for immunological recovery and perhaps also for rapid repair of various damaged tissues, especially in the intestines, and (4) by functioning as an antifibrogenic agent. A detailed discussion is given of possible mechanisms involved both in the antioxidant effects of taurine, in its anti-inflammatory effects and in its role as a growth factor for leukocytes and nerve cells, which might be closely related to its role as an osmolyte important for cellular volume regulation because of the close connection between cell volume regulation and the regulation of protein synthesis as well as cellular protein degradation. While taurine supplementation alone would be expected to exert a therapeutic effect far better than negligible in patients that have been exposed to high doses of ionizing radiation, it may on theoretical grounds be expected that much better results may be obtained by using taurine as part of a multifactorial treatment strategy, where it may interact synergistically with several other nutrients, hormones or other drugs for optimizing antioxidant protection and minimizing harmful posttraumatic inflammatory reactions, while using other nutrients to optimize DNA and tissue repair processes, and using a combination of good diet, immunostimulatory hormones and perhaps other nontoxic immunostimulants (such as beta-glucans) for optimizing the recovery of antiviral and antibacterial immune functions. Similar multifactorial treatment strategies may presumably be helpful in several other disease situations (including severe infectious diseases and severe asthma) as well as for treatment of acute intoxications or acute injuries (both mechanical ones and severe burns) where severely enhanced oxidative and/or nitrative stress and/or too much secretion of vasodilatory neuropeptides from C-fibres are important parts of the pathogenetic mechanisms that may lead to the death of the patient. Some case histories (with discussion of some of those mechanisms that may have been responsible for the observed therapeutic outcome) are given for illustration of the likely validity of these concepts and their relevance both for treatment of severe infections and non-infectious inflammatory diseases such as asthma and rheumatoid arthritis.