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A molecular analysis of archaeal communities in eight sponges collected along the coast of Cheju Island, Korea was conducted using terminal-restriction fragment length polymorphism (T-RFLP) in conjunction with sequencing analysis of 16S rDNA clones. The terminal-restriction fragment (T-RF) profiles showed that each sponge had a simple archaeal community represented by a single major peak of the same size except for one unidentified sponge (01CJ20). In order to identify the components of the community, 170 archaeal 16S rDNA clones were recovered from sponges and analyzed by RFLP typing. Sequences of 19 representative clones for all RFLP types found in each sponge were determined and phylogenetic analysis was carried out. Seventeen of these archaeal 16S rDNA clones showed a high similarity to marine group I, belonging to the crenarchaeotes. In the phylogenetic tree, 15 archaeal clones were grouped into five sponge-associated archaeal clusters. In the unidentified sponge sample (01CJ20), one major T-RF peak was represented by a single RFLP type (40 clones), which implied a specific relationship between the sponge and its symbiotic archaeal components. [Copyright &y& Elsevier]

Abstract: Prodigiosin was isolated from marine bacteria Hahella chejuensis which has been recently discovered from Marado, Cheju Island, Republic of Korea. Immunosuppressive properties have been reported for prodigiosin members such as undecylprodigiosin, metacycloprodigiosin, prodigiosin and its synthetic analogue PNU156804 (PNU). However, the effect of this agent on macrophage function has not been characterized in detail. In the present study, we examined the effects of prodigiosin on the production of inflammatory cytokines and nitric oxide (NO) in lipopolysaccharide (LPS)-activated murine macrophage. When thioglycollate-elicited macrophages pre-exposed to prodigiosin (1–100 ng/ml) were stimulated with LPS, pretreatment with prodigiosin resulted in the inhibition of NO production and inducible nitric oxide synthase (iNOS) protein and mRNA expression in a concentration-dependent manner. In contrast, the production of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1) and IL-6 was not altered. Inhibition of iNOS protein expression appears to be at the transcriptional level, since prodigiosin decreased LPS-induced NF-κB activity through preventing the degradation of IkBα, with significant inhibition achieved following pretreatment with prodigiosin. However, prodigiosin did not exert any effect on AP-1 activity. Prodigiosin blocked phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase (JNK), but not that of extracellular signal-regulated kinase 1/2 (ERK 1/2). These results indicate that the inhibition of these signaling molecules expression was correlated with the reduced production of NO in macrophages. Taken together, the present data suggest that prodigiosin reduces NO production and iNOS expression by inhibiting LPS-triggered p38 MAPK and JNK phosphorylation and NF-κB activation, thereby implicating a mechanism by which prodigiosin may exert its immunosuppressive effects. [Copyright &y& Elsevier]

Abstract: This study examined the ability of microalgal sulfated exopolysaccharide (MSE) from marine microalga Gyrodinium impudicum (strain KG03) to induce secretory and cellular responses in murine peritoneal macrophages. The cytotoxicity induced by preincubating tumor cells with MSE was demonstrated to be concentration-dependent. The MSE-induced tumoricidal activity was partially abrogated by a NO inhibitor, whereas the anti-TNF-α and anti-IFN-α/β antibodies as well as the scavengers of reactive oxygen intermediates had no effect. In addition, supernatants from murine peritoneal macrophages treated with MSE contained nitrite and their iNOS enzymatic activity was significantly increased. Therefore, the tumoricidal activity induced by MSE appeared to be mediated by the production of NO. Treating the macrophages with a JNK inhibitor (SP600125) partially blocked the tumoricidal activation and NO production induced by MSE, whereas inhibitors of the other kinases did not have an inhibitory effect. These results suggest that MSE induces NO production via the JNK dependent pathway. Furthermore, electrophoretic mobility shift assay analyses revealed that the MSE treatment induced the activation of the NF-κB transcription factor. Overall, these results indicate that the tumoricidal activity induced by MSE is mainly due to NO production, and the activation of macrophage by MSE is mediated probably via the NF-κB and JNK pathway. [Copyright &y& Elsevier]

Abstract: A new cyclic depsipeptide stereocalpin A (1) has been isolated from the MeOH extract of the Antarctic lichen Stereocaulon alpinum by various chromatographic methods. The structure of stereocalpin A (1) was mainly determined by analysis of the NMR spectroscopic data and by chemical methods. Stereocalpin A (1) is a unique cyclic peptide incorporating an unprecedented 5-hydroxy-2,4-dimethyl-3-oxo-octanoic acid in the structure. Stereocalpin A (1) shows moderate cytotoxicity against three human solid tumor cell lines. [Copyright &y& Elsevier]

Pedobacter cryoconitis PAMC 27485, an aerobic, Gram-negative, facultatively psychrophilic bacterium, was isolated from Antarctic soil. Here we report the complete genome of P. cryoconitis PAMC 27485, which contains a type II CRISPR-Cas system and genes encoding useful enzymes (e.g. proteases). The genome sequence of P. cryoconitis PAMC 27485 could provide insights into its adaptive immune system against foreign genetic elements and biotechnological potential. [ABSTRACT FROM AUTHOR]

Obesity is a serious global health problem. Natural substances that could be effective remedies for treatment of obesity, and which are relatively safe, are desired. The aim of this study was to examine the anti-obesity effect and the mechanism of ramalin in 3T3-L1 preadipocytes and high fat diet (HFD)-induced obese mice. In this study, 3T3-L1 cells were treated with various concentrations of ramalin (1, 5, and 10 μg/ml). Ramalin reduced the accumulation of intracellular lipid droplets in 3T3-L1 cells. In addition, ramalin inhibited 3T3-L1 adipocyte differentiation by blocking adipogenic gene expression including CCAAT enhancer binding proteins (C/EBPs), peroxisome proliferator-activated receptors γ (PPARγ), adipocyte fatty acid-binding protein (aP2), and leptin. The suppression of adipogenesis by ramalin was mediated through the inhibition of MAPK pathways. Ramalin also reduced the secretion of TNF-α and IL-6 in 3T3-L1 adipocytes. Oral administration of ramalin (50 and 100 mg/kg) to HFD-fed mice reduced body weight gain and abdominal fat accumulation without changes in food intake. Ramalin also attenuated organ weight and basal serum level by inhibiting Iiver X receptors (LXRs), sterol regulatory element-binding protein-1c (SREBP-1c), and lipoprotein lipase (LPL) mRNA expression in HFD-fed mice. Taken together, these results indicate that ramalin inhibits adipogenesis in 3T3-L1 preadipocytes and prevents HFD-induced obesity. The present study also provides insight into the mechanisms underlying the anti-obesity activity of ramalin and suggests that ramalin has the potential to prevent obesity. [ABSTRACT FROM AUTHOR]

Abstract: Aims: The expression of cell adhesion molecules on vascular smooth muscle cells is central to leukocyte recruitment and progression of atherosclerotic disease. Ohioensin F, a chemical compound of the Antarctic moss Polyerichastrum alpinum, exhibited inhibitory activity against protein tyrosine phosphatase 1B and antioxidant activity. However, published scientific information regarding other biological activities and pharmacological function of ohioensin F is scarce. In the present study, we aimed to examine the in vitro effects of ohioensin F on the ability to suppress TNF-α-induced adhesion molecule expression in vascular smooth muscle cells (VSMCs). Main methods: The inhibitory effect of ohioensin F on TNF-α-induced upregulation in expression of adhesion molecules was investigated by enzyme-linked immunosorbent assay, cell adhesion assay, RT-PCR, western blot analysis, immunofluorescence, and transfection and reporter assay, respectively. Key findings: Pretreatment of VSMCs with ohioensin F at nontoxic concentrations of 0.1–10μg/ml dose-dependently inhibited TNF-α-induced expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). In addition, ohioensin F suppressed adhesion of THP-1 monocytes to TNF-α-stimulated VSMCs. Ohioensin F reduced TNF-α-induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38, ERK, JNK and Akt. Finally, ohioensin F inhibited TNF-α-induced CAM mRNA expression and NK-κB translocation. Significance: These results suggest a new mechanism of ohioensin F''s anti-inflammatory action, owing to the negative regulation of TNF-α-induced adhesion molecule expression, monocyte adhesion and ROS production in vascular smooth muscle cells. Our finding also supports ohioensin F as a potential pharmacological, anti-inflammatory molecule that has a protective effect on the atherosclerotic lesion. [Copyright &y& Elsevier]

Abstract: Up-regulation of cell adhesion molecules on vascular smooth muscle cells (VSMCs) and leukocyte recruitment to the vascular wall contribute to vascular inflammation and atherosclerosis. Stereocalpin A, a chemical compound of the Antarctic lichen Ramalina terebarata, displays tumoricidal activity against several different tumor cell types. However, other biological activities of stereocalpin A and its molecular mechanisms remain unknown. In this study, our work is directed toward studying the in vitro effects of stereocalpin A on the ability to suppress the expression of adhesion molecules induced by TNF-α in vascular smooth muscle cells. Pretreatment of VSMCs for 2h with stereocalpin A at nontoxic concentrations of 0.1–10μg/ml inhibited TNF-α-induced adhesion of THP-1 monocytic cells and expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Stereocalpin A reduced TNF-α-induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38, ERK, JNK and Akt. Stereocalpin A also inhibited NK-κB activation induced by TNF-α. Moreover, stereocalpin A inhibited TNF-α-induced ΙκΒ kinase activation, subsequent degradation of ΙκΒα, and nuclear translocation of NF-κB. Hence, we describe a new anti-inflammatory activity and mechanism of stereocalpin A, owing to the negative regulation of TNF-α-induced adhesion molecule and MCP-1 expression, monocyte adhesion and ROS production in vascular smooth muscle cells. These results suggest that stereocalpin A has the potential to exert a protective effect by modulating inflammation within the atherosclerotic lesion. [Copyright &y& Elsevier]

Abstract: An endochitinase was previously purified and the gene was cloned from the psychrophilic Antarctic bacterium, Sanguibacter antarcticus (KCTC 13143). In the present study, recombinant endochitinase, rChi21702, was expressed using a yeast expression system (Pichia pastoris) and codon optimization. The expressed rChi21702 was purified by Phenyl-Sepharose column chromatography. Optimal expression yielded 1-mg purified enzyme from 1-L bioreactor culture. When p-NP-(GlcNAc)2 was used as a substrate, the specific activity of the enzyme was determined to be 20U/mg. In vitro assays and thin-layer chromatography demonstrated that the recombinant enzyme has endochitinase activity that produces diacetyl-chitobiose as a dominant end product when chitooligomers, colloidal chitin, and the chromogenic p-NP-(GlcNAc)2 are used as substrates. Optimal activity for rChi21702 was observed at 37°C and a pH of 7.6. Interestingly, rChi21702 exhibited 63% of optimal activity at 10°C and 44% activity at 0°C. Taken together, the results indicate that rChi21702 has psychrotolerant endochitinase activity even after recombinant expression in yeast cells. [Copyright &y& Elsevier]

Abstract: The psychrotrophic Sanguibacter antarcticus KOPRI 21702T, isolated from Antarctic seawater, produced a cold-adapted chitinolytic enzyme that is a new 55kDa family 18 chitinase (Chi21702). Chi21702 exhibited high activities toward pNP-(GlcNAc)2 and pNP-(GlcNAc)3 with no activity for pNP-GlcNAc, indicating that it prefers chitin chains longer than dimers, just as endochitinases do. A mixture of GlcNAc and GlcNAc2 was produced as a main product by Chi21702 activity from chitin oligosaccharides and swollen chitin, while less GlcNAc3 was produced. These results show that Chi21702 has an endochitinase activity, randomly hydrolyzing chitin at internal sites. Chi21702 displayed chitinase activity at 0–40°C (optimal temperature of 37°C), maintained its activity at pH 4–11 (optimal pH of 7.6). Interestingly, Chi21702 exhibited relative activities of 40% and 60% at 0 and 10°C, respectively, in comparison to 100% at 37°C, which is higher than those of the previously characterized, cold-adapted, chitinases from bacterial strains. [Copyright &y& Elsevier]

The selective inhibition of PTP1B has been widely recognized as a potential drug target for the treatment of type 2 diabetes and obesity. In the course of screening for PTP1B inhibitory natural products, the MeOH extract of the dried sample of the Antarctic lichen Umbilicaria antarctica was found to exhibit significant inhibitory effect, and the bioassay-guided fractionation and purification afforded three related lichen metabolites 1- 3. Compounds 1- 3 were identified as gyrophoric acid ( 1), lecanoric acid ( 2), and methyl orsellinate ( 3) mainly by analysis of NMR and MS data. These compounds inhibited PTP1B activity with 50% inhibitory concentration values of 3.6 ± 0.04 μM, 31 ± 2.7 μM, and 277 ± 8.6 μM, respectively. Furthermore, the kinetic analysis of PTP1B inhibition by compound 1 suggested that the compound inhibited PTP1B activity in a non-competitive manner. [ABSTRACT FROM AUTHOR]

Abstract: Proteorhodopsin (PR), a retinal-containing seven transmembrane helix protein, functions as a light-driven proton pump. Using PCR, we isolated 18 PR variants originating from the surface of the Arctic Ocean. Their absorption maxima were between 517 and 546nm at pH 7. One of the isolates turned out to be identical to GPR (green light-absorbing proteorhodopsin) from Monterey Bay. Interestingly, 10 isolates had replaced a tyrosine in the retinal-binding site (Tyr200 in GPR) with Asn. They showed a slower photocycle, more blue-shifted absorption maxima at pH 10, and relatively larger ΔH and ΔS of activation of the transition between the O intermediate and the ground state compared to GPR. [Copyright &y& Elsevier]

Abstract: Ohioensins F and G (1 and 2), two new benzonaphthoxanthenones, have been isolated from the MeOH extract of Antarctic moss Polytrichastrum alpinum by various chromatographic methods. The structures of these compounds were determined mainly by analysis of NMR spectroscopic data. The known compounds ohioensins A and C (3 and 4) were also obtained. Compounds 1–4 showed potent inhibitory activity against therapeutically targeted protein tyrosine phosphatase 1B (PTP1B). Kinetic analysis of PTP1B inhibition by ohioensin F (1) suggested that benzonaphthoxanthenones inhibited PTP1B activity in a non-competitive manner. [Copyright &y& Elsevier]

Abstract: The flocculating activity of an exopolysaccharide, p-KG03, produced by a marine dinoflagellate Gyrodinium impudicum KG03 was investigated. The p-KG03 was a highly sulfated exopolysaccharide that showed strong antiviral activity against encephalomyocarditis virus (EMCV) and immunostimulating activity by NK cell activation. For the industrial applications of p-KG03, as the bioflocculant agent, p-KG03 showed that more than 90% of the flocculating activity in kaolin suspension occurred at concentrations of 0.5mg/l with the maximum at 1.0mg/l. However, flocculation decreased from 2.5mg/l. The flocculation rate increased linearly with concentration and was higher than that observed in commercial products such as polyacrylamide (≈1.0mg/l) or zooglan (≈3.0mg/l). The p-KG03 was an effective flocculant under acidic conditions (pH 3–6) and over a wide temperature range (4–90°C). The presence of cations did not enhance flocculating activity. The average molecular mass, as determined by gel filtration chromatography, was about 1.87×103 KDa. Galactose was the main sugar in p-KG03, which also contained uronic acid (2.9%, w/w) and sulfate groups (10.3%, w/w). The infrared spectrum of p-KG03 showed absorption bands of carboxylate groups. Thermogravimetric analysis indicated a degradation temperature (T d) of 250°C. Several other properties of p-KG03 such as intrinsic viscosity, the rheological behavior, consistency index (k) and flow behavior index (η) were also studied. [Copyright &y& Elsevier]

A marine microalga Gyrodinium impudicum strain KG03 produced sulfated exopolysaccharide designated as p-KG03, which showed a strong antiviral activity against encephalomyocarditis virus (EMCV). To optimize culture conditions for the production of p-KG03, mineral salts, vitamins, plant growth hormones, temperature, pH and light conditions were examined. From this study, M-KG03 medium for the maximum production of p-KG03 was suggested as follows; NH4Cl 75 μM, NaH3PO4 200 μM, NaHCO3 50 μM, Na2SO4 10 μM, FeCl2·6H2O 10 μM, MnCl2·4H2O 0.1 μM, vitamin B12 0.75 μg, naphthalene acetic acid (NAA) 7.5 μg and myo-inositol 200 mg per liter of aged sea water. The optimal temperature and pH were 22.5 °C and 8.0, respectively. The optimal light conditions of intensity and period were 150 μE m−2 s−1 and 16:8 h light:dark cycle. Finally, the cell growth and p-KG03 production were measured in one liter of M-KG03 medium with 1% CO2 and 50 ml min−1 of airflow using two liters airlift balloon type photobioreactor (ABTPR). At these optimal conditions, p-KG03 production and cell growth were 134.6±5.9 mg l−1 and 123,076±1,597 cells ml−1, respectively, representing a 7.7 and 5.1 times compared with f/2 medium with Erlenmeyer flask culture (p-KG03 production 17.5±1.3 mg l−1 and cell growth 24,311±1,291 cells ml−1). [Copyright &y& Elsevier]

Abstract: Seven phenolic lichen metabolites (1–7) have been isolated from a methanol extract of the Antarctic lichen Stereocaulon alpinum by various chromatographic methods. The structures of these compounds were determined mainly by analysis of NMR spectroscopic data. A depsidone-type compound, lobaric acid (1) and two pseudodepsidone-type compounds, 2 and 3, exhibited potent inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) with IC50 values of 0.87μM, 6.86μM, and 2.48μM, respectively. Kinetic analyses of PTP1B inhibition by compounds 1 and 2 suggested that these compounds inhibited PTP1B activity in a non-competitive manner. [Copyright &y& Elsevier]

Here, we present the first complete genome sequence of the strain PAMC 20958 T from the genus Halocynthiibacter . Halocynthiibacter arcticus PAMC 20958 T , isolated from a marine sediment of the Arctic, is a gram-negative, aerobic, and rod-shaped bacterium. The complete genome contains 4,329,554 base pairs with 53.21% GC content and a 44,566 base pair plasmid with 48.72% GC content. This genome contained genes encoding alkaline phosphatase and lipase, and genes that confer resistance to arsenic, cadmium, tellurite, and acriflavin. [ABSTRACT FROM AUTHOR]