Key aspects of the iodine metabolism in brown algae: a brief critical review.

Brown algae include the strongest accumulators of iodine known among living systems. This paper reviews the current state of bioinorganic research in the field, focusing on the models Laminaria digitata, Macrocystis pyrifera and Ectocarpus siliculosus, and covering uptake and efflux, localization and biological significance of storage, as well as marine and atmospheric chemistry of iodine.

Immunomodulatory Effects of Monascus spp.-Fermented Sacccharina japonica Extracts on the Cytokine Gene Expression of THP-1 Cells.

The immunomodulatory effects of Monascus-fermented Saccharina japonica extract on anti- and pro-inflammatory cytokines gene expression of THP-1 cells were evaluated. Extracts of fermented samples showed higher phenolic, flavonoid, protein, and reducing sugar contents than unfermented one. Fermented samples were rich in many bioactive compounds determined by GC-MS analyses and showed cell viability greater than 85% in MTS assay. Regarding the anti-inflammatory and pro-inflammatory activities of the different samples, Q-PCR analyses revealed that IL-10 gene expression in THP-1 cells was significantly higher (p < 0.05) in cells treated with the SjMp or SjMk sample than those treated with the unfermented sample. Cells treated with the SjMp extract or lipopolysaccharide (LPS) showed significantly (p < 0.05) higher relative gene expression of IL-4 cytokine than cells treated with SjMk or SjU extracts. The relative gene expression of IFN-α was higher in cells treated with SjMp followed by LPS, SjMk, and SjU. TGF-ß expression was higher in LPS-stimulated cells followed by SjMk and other samples. Cells treated with SjMp exhibited significantly higher pro-inflammatory (IL-6, IL-8, TNF-α, and NF-κB) cytokine gene expression than cells treated with SjU. These results revealed that extracts from S. japonica fermented with Monascus spp. regulate cytokine gene expression. Graphical abstract ᅟ.

Kelps feature systemic defense responses: insights into the evolution of innate immunity in multicellular eukaryotes.

Brown algae are one of the few eukaryotic lineages that have evolved complex multicellularity, together with Opisthokonts (animals, fungi) and Plantae (land plants, green and red algae). In these three lineages, biotic stresses induce similar local defense reactions. Animals and land plants also feature a systemic immune response, protecting the whole organism after an attack on one of its parts. However, the occurrence of systemic defenses has never been investigated in brown algae. We elicited selected parts of the kelp Laminaria digitata and monitored distant, nonchallenged areas of the same individual for subsequent defense reactions. A systemic reaction was detected following elicitation on a distant area, including an oxidative response, an increase in haloperoxidase activities and a stronger resistance against herbivory. Based on experiments with pharmacological inhibitors, the liberation of free fatty acids is proposed to play a key role in systemic signaling, reminiscent of what is known in land plants. This study is the first report, outside the phyla of Opisthokonts and Plantae, of an intraorganism communication leading to defense reactions. These findings indicate that systemic immunity emerged independently at least three times, as a consequence of convergent evolution in multicellular eukaryotic lineages.

Protective effect of Laminaria japonica with probiotics on murine colitis.

Inflammatory bowel disease (IBD) is a chronically relapsing inflammatory disorder of the gastrointestinal tract. Most IBD treatments are unsatisfactory; therefore, various dietary supplements have emerged as promising interventions. Laminaria japonica (LJ) is an edible seaweed used to regulate digestive symptoms. Probiotics have been reported to improve digestive problems and their simultaneous administration with seaweeds has been shown to produce synergistic therapeutic effects. Here, we investigated the effect of LJ combination with probiotics on dextran sodium sulfate-induced colitis model in mice. Aqueous LJ extracts (LJE) at doses from 100 to 300 mg/kg and probiotics at a dose of 300 mg/kg were orally administered for 7 days. Body weight, colon length, histological score, macroscopic damage, and the levels of cytokines IFN- γ , IL-1 ß , IL-6, IL-10, IL-12 (P40), IL-12 (P70), IL-17, and TNF- α were assessed. LJE alone caused a significant improvement of colitis signs such as colon length, histological score, and IL-1 ß and IL-6 production. LJE and probiotics demonstrated a synergistic effect by the histological score and levels of IL-1 ß , IL-6, and IL-12 (P40) but not IFN- γ , IL-10, and IL-12 (P70). In conclusion, LJE was effective in inducing protection against colitis in mice and acted synergistically with probiotics.

An initial event in the insect innate immune response: structural and biological studies of interactions between ß-1,3-glucan and the N-terminal domain of ß-1,3-glucan recognition protein.

In response to invading microorganisms, insect ß-1,3-glucan recognition protein (ßGRP), a soluble receptor in the hemolymph, binds to the surfaces of bacteria and fungi and activates serine protease cascades that promote destruction of pathogens by means of melanization or expression of antimicrobial peptides. Here we report on the nuclear magnetic resonance (NMR) solution structure of the N-terminal domain of ßGRP (N-ßGRP) from Indian meal moth (Plodia interpunctella), which is sufficient to activate the prophenoloxidase (proPO) pathway resulting in melanin formation. NMR and isothermal calorimetric titrations of N-ßGRP with laminarihexaose, a glucose hexamer containing ß-1,3 links, suggest a weak binding of the ligand. However, addition of laminarin, a glucose polysaccharide (~6 kDa) containing ß-1,3 and ß-1,6 links that activates the proPO pathway, to N-ßGRP results in the loss of NMR cross-peaks from the backbone (15)N-(1)H groups of the protein, suggesting the formation of a large complex. Analytical ultracentrifugation (AUC) studies of formation of the N-ßGRP-laminarin complex show that ligand binding induces self-association of the protein-carbohydrate complex into a macro structure, likely containing six protein and three laminarin molecules (~102 kDa). The macro complex is quite stable, as it does not undergo dissociation upon dilution to submicromolar concentrations. The structural model thus derived from this study for the N-ßGRP-laminarin complex in solution differs from the one in which a single N-ßGRP molecule has been proposed to bind to a triple-helical form of laminarin on the basis of an X-ray crystallographic structure of the N-ßGRP-laminarihexaose complex [Kanagawa, M., Satoh, T., Ikeda, A., Adachi, Y., Ohno, N., and Yamaguchi, Y. (2011) J. Biol. Chem. 286, 29158-29165]. AUC studies and phenoloxidase activation measurements conducted with the designed mutants of N-ßGRP indicate that electrostatic interactions involving Asp45, Arg54, and Asp68 between the ligand-bound protein molecules contribute in part to the stability of the N-ßGRP-laminarin macro complex and that a decreased stability is accompanied by a reduced level of activation of the proPO pathway. An increased level of ß-1,6 branching in laminarin also results in destabilization of the macro complex. These novel findings suggest that ligand-induced self-association of the ßGRP-ß-1,3-glucan complex may form a platform on a microbial surface for recruitment of downstream proteases, as a means of amplification of the initial signal of pathogen recognition for the activation of the proPO pathway.

[Production of cytokines by murine bone marrow dendritic cells in vitro mediated by sulfated polysaccharides obtained from sea brown algae].

AIM: To assess in vitro cytokine production by murine bone marrow dendritic cells (DC) matured under the effect of sulfated polysaccharides--fucoidanes from sea brown algae Laminaria cichorioides and Laminaria japonica. MATERIALS AND METHODS: CBA line mice were used to obtain bone marrow origin precursors of DC. Isolation and study of chemical composition and structure of fucoidanes were performed using modern research methods. Expression of surface markers was determined by flow cytometry (FACS-analysis) using monoclonal antibodies to respective antigens. Levels of cytokine production were measured by t-ELISA using kits manufactured by Biosource (Belgium). RESULTS: I was determined that fucoidans induce maturation of DC that was evident by expression of terminal differentiation marker CD83, activation marker CD38, enhanced expression of costimulating CD86, antigen-presenting MHC II and adhesive CD11c molecules. Fucoidanes stimulate DC to produce proinflammatory (TNF-alpha, IL-6, IL-1beta) and regulatory (IL-12) cytokines. Fucoidanes enhance expression of TLR-2 and TLR-4 but do not influence on expression of TLR-9. CONCLUSION: It was shown that fucoidanes from sea brown algae L. cichorioides and L. japonica activate innate immunity system that is evident by enhanced expression of surface molecules associated with DC maturation and increased production of proinflammatory and regulatory cytokines by DC. Enhanced expression of TLR-2 and TLR-4 allows to suppose that studied fucoidanes could have anti-infective effect in vivo.

Quantification and localization of fucoidan in Laminaria japonica using a novel antibody.

The establishment of a simple technique to determine the concentration of fucoidan was developed by using a monoclonal antibody against fucoidan. This antibody reacted with fucoidans purified from Laminaria japonica Areschoug (Makombu in Japanese) and Kjellmaniella gyrate Miyabe (Gagome), but not with polysaccharides from Undaria pinnatifida Suringar (Wakame). Neither laminarin nor algenic acid, which are constituents in Laminaria japonica, were recognized by the prepared antibody. Application of the enzymed-linked immunosorbent assay (ELISA) inhibition assay increased the specificity of fucoidan in measuring the fucoidan contents. On the basis of these results, it was ascertained that the ELISA inhibition assay of using the anti-fucoidan monoclonal antibody was rapid, accurate, and sensitive in measuring the content of fucoidan. In addition, the localization of fucoidan in Laminaria japonica was investigated. This is the first report of fucoidan being restricted to the outer cortical layer.

Patterns of gene expression induced by oligoguluronates reveal conserved and environment-specific molecular defense responses in the brown alga Laminaria digitata.

* Until now, no information has been available on the transcriptional response to the transduction of defense signals in brown seaweeds that leads to active resistance against pathogens or grazers. * Using a polymerase chain reaction (PCR)-based, subtractive cDNA approach combined with filter arrays we demonstrated that Laminaria digitata exhibits a rapid response to oligoguluronate elicitors. The transcription levels of several genes were validated by quantitative real-time reverse-transcription PCR and further analysed using pharmacological approaches. * Fifty upregulated genes were identified by differential screening in elicited algae over a 24-h time-course. These genes were related to oxidative stress responses, production of antimicrobial secondary compounds or cell wall strengthening. Moreover, pharmacological tests showed that intracellular signal transduction is likely to involve reactive oxygen species. A new oligoguluronate-inducible vanadium-dependent haloperoxidase (vHPO), specific to iodide was also characterized. The transcription of several vHPO genes was shown to be tightly regulated. * Taken together, our data show that early transcriptional defense responses in L. digitata are similar to those in land plants but also include novel defense responses that involve tightly regulated iodine metabolism.

Morphological and immunological characterization of immunostimulatory complexes based on glycoglycerolipids from Laminaria japonica.

Some physicochemical properties of glycoglycerolipids (monogalactosyldiacylglycerol, digalactosyldiacylglycerol and sulfoquinovosyldiacylglycerol) from the sea algae Laminaria japonica, as well as their ability to become incorporate into immunostimulating complexes (ISCOMs), used as a delivery system of microbial and tumor antigens in vesicular form, were studied. These glycolipids were found to differ essentially in fatty acid composition, unsaturation index and thermotropic behavior. The possibility of ISCOM modification by embedding the glycolipids studied instead of a phospholipid component in vesicles was shown. A preliminary research of the immunogenicity of the pore-forming protein from Yersinia pseudotuberculosis in modified (by monogalactosyldiacylglycerol) and typical (egg phosphatidylcholine) ISCOMs did not reveal a significant enhancement of immune response in comparison with that of isolated protein.

Two cases of anaphylaxis after laminaria insertion.

Anaphylaxis following laminaria insertion rarely occurs but may be a life-threatening condition. Laminaria tents, prepared from natural sea kelp, are commonly used prior to elective termination of pregnancy to achieve cervical dilatation. We report herein two cases of anaphylaxis caused by IgE-mediated hypersensitivity to laminaria. Two women, each of whom had undergone at least one previous abortion where a laminaria had been utilized, developed anaphylactic reaction following laminaria insertion. The reaction included urticaria, nausea, breathing difficulty, and hypotension. The patients subsequently underwent skin testing and measurement of serum specific IgE level to laminaria extract, and were shown to elicit positive responses to laminaria. The implication and impact of laminaria allergy on gynecologic procedures are significant and this allergy should be included in the list of differential diagnoses for hypersensitive reaction in gynecologic procedures.

Two Cases of Anaphylaxis After Laminaria Insertion

Anaphylaxis following laminaria insertion rarely occurs but may be a life-threatening condition. Laminaria tents, prepared from natural sea kelp, are commonly used prior to elective termination of pregnancy to achieve cervical dilatation. We report herein two cases of anaphylaxis caused by IgE-mediated hypersensitivity to laminaria. Two women, each of whom had undergone at least one previous abortion where a laminaria had been utilized, developed anaphylactic reaction following laminaria insertion. The reaction included urticaria, nausea, breathing difficulty, and hypotension. The patients subsequently underwent skin testing and measurement of serum specific IgE level to laminaria extract, and were shown to elicit positive responses to laminaria. The implication and impact of laminaria allergy on gynecologic procedures are significant and this allergy should be included in the list of differential diagnoses for hypersensitive reaction in gynecologic procedures.

Purification, characterization, and immunological cross-reactivity of alginates produced by mucoid Pseudomonas aeruginosa from patients with cystic fibrosis.

Alginates from nine mucoid Pseudomonas aeruginosa isolates from patients with cystic fibrosis were purified by repeated ethanol precipitation, nuclease digestion, anion-exchange chromatography, dialysis, and lyophilization. Uronic acid constituted 72% of the dry weight when mannuronolactone was used as the internal standard in the carbazole-borate assay for uronic acids. The average degree of acetylation was 16%, and the ratio of mannuronic acid to gluluronic acid was 4.7. No homopolymeric blocks of guluronic acid were found when analyzed by nuclear magnetic resonance spectroscopy. Contaminating proteins were denatured by heating, and during purification the content of protein relative to alginate fell from 566 to 0.9%. The content of lipopolysaccharide was 0.012%. No immunological or biological activity was attributable to the protein or lipopolysaccharide content as estimated by immunoblotting, enzyme-linked immunosorbent assay (ELISA), and a neutrophil chemotaxis assay. Rabbits were hyperimmunized with P. aeruginosa alginates and alginate from the seaweed Laminaria hyperborea, and an ELISA that detected alginate-specific antibodies was developed. Antibodies to P. aeruginosa alginate were detected by ELISA in 1:4,000 dilutions of serum from patients with cystic fibrosis with chronic P. aeruginosa lung infection. The serological cross-reactions between serum from the nine patients with cystic fibrosis and the corresponding P. aeruginosa alginates were investigated and showed considerable heterogeneity. This finding indicates that P. aeruginosa alginate from more than one P. aeruginosa strain should be used in serological tests. There was no serological cross-reactivity between P. aeruginosa and Laminaria hyperborea alginate in either rabbits or patients with cystic fibrosis.