Astaxanthin Extract from Haematococcus pluvialis and Its Fractions of Astaxanthin Mono- and Diesters Obtained by CCC Show Differential Antioxidant and Cytoprotective Effects on Naïve-Mouse Spleen Cells

Carotenoids are the most abundant lipid-soluble phytochemicals and are used as dietary supplements to protect against diseases caused by oxidative stress. Astaxanthin, a xanthophyll carotenoid, is a very potent antioxidant with numerous beneficial effects on cellular functions and signaling pathways. In this study, using spleen cells from healthy Balb/c mice, we report the bio-functional effects of an astaxanthin-rich extract (EXT) prepared from the microalga Haematococcus pluvialis and its astaxanthin monoesters-rich fraction (ME) and astaxanthin diesters-rich fraction (DE) obtained by fractionation of EXT using countercurrent chromatography (CCC). After incubation under standard culture conditions (humidity, 37 °C, 5% CO₂, atmospheric oxygen), the viability of untreated splenocytes, as determined by the trypan blue exclusion assay, the MTT assay, and the neutral red assay, decreases to approximately 75% after 24 h compared with naïve splenocytes. This effect correlated with the decrease in mitochondrial membrane potential and the transition of ~59% of cells to the early stage of apoptosis, as well as with the decreased ROS production, indicating that hyperoxia in cell-culture deteriorates cell functions. They are restored or stimulated by co-cultivation with EXT, ME, and DE up to 10 µg/mL in the order EXT > DE > ME, suggesting that esterification increases bioavailability to cells in vitro. ROS and H₂O₂ concentrations reflect mRNA transcriptional activity of Nrf2, superoxide dismutase 1 (SOD1), catalase, and glutathione peroxidase 1, as well as SOD-mediated ROS conversion, whereas they inversely correlate with iNOS-mediated NO production. The highest-tested concentration of EXT, ME, and DE (40 µg/mL) is detrimental to cells, probably because of the overwhelming scavenging activity of astaxanthin and its esters for the reactive oxygen/nitrogen species required for cellular functions and signal transduction at low physiological concentrations. In this study, we demonstrate that differential activities of ME and DE contribute to the final antioxidant and cytoprotective effects of astaxanthin extract, which is beneficial in preventing a wide range of ROS-induced adverse effects, with DE being more effective. In addition, the selection of physioxia-like conditions for pharmacological research is highlighted.

Hibberdia magna (Chrysophyceae): a promising freshwater fucoxanthin and polyunsaturated fatty acid producer

BACKGROUND

Algae are prominent producers of carotenoids and polyunsaturated fatty acids which are greatly prized in the food and pharmaceutic industry. Fucoxanthin represents a notable high-value carotenoid produced exclusively by algae. Its benefits range far beyond just antioxidant activity and include cancer prevention, anti-diabetes, anti-obesity, and many other positive effects. Accordingly, large-scale microalgae cultivation to produce fucoxanthin and polyunsaturated fatty acids is still under intensive development in the commercial and academic sectors. Industrially exploitable strains are predominantly derived from marine species while comparable freshwater fucoxanthin producers have yet to be explored.

RESULTS

In this study, we searched for freshwater fucoxanthin producers among photoautotrophic flagellates including members of the class Chrysophyceae. The initial screening turned our attention to the chrysophyte alga Hibberdia magna. We performed a comprehensive cultivation experiments using a temperature × light cross-gradient to assess the impact of these conditions on the target compounds productivity. Here we present the observations that H. magna simultaneously produces fucoxanthin (max. 1.2% dry biomass) and polyunsaturated fatty acids (max. ~ 9.9% dry biomass) and is accessible to routine cultivation in lab-scale conditions. The highest biomass yields were 3.73 g L^-1 accompanied by maximal volumetric productivity of 0.54 g L^-1 d^-1 which are comparable values to marine microalgae fucoxanthin producers in phototrophic mode. H. magna demonstrated different optimal conditions for biomass, fucoxanthin, and fatty acid accumulation. While maximal fucoxanthin productivities were obtained in dim light and moderate temperatures (23 °C× 80 µmol m^-2 s^-1), the highest PUFA and overall biomass productivities were found in low temperature and high light (17-20 °C × 320-480 µmol m^-2 s^-1). Thus, a smart biotechnology setup should be designed to fully utilize H. magna biotechnological potential.

CONCLUSIONS

Our research brings pioneer insight into the biotechnology potential of freshwater autotrophic flagellates and highlights their ability to produce high-value compounds. Freshwater fucoxanthin-producing species are of special importance as the use of sea-water-based media may increase cultivation costs and prohibits inland microalgae production.

Neurotoxicity and Immunotherapy

BACKGROUND

Great progress has recently been made in immunotherapy of solid carcinomas. The advent of immunotherapy with checkpoint inhibitors has brought not only a completely different mechanism of action but also different types of adverse reactions. These adverse reactions are similar to those of autoimmune diseases and are referred to as immune-related adverse events. Most adverse reactions are due to lower grade toxic effects. Neurotoxicity is a less frequent. On the other hand, with the spread of immunotherapy, it can be assumed that adverse events with a lower incidence may occur in a relatively higher frequency due to borader usage of immunotherapeutics and thus, physicians outside of cancer centres may be presented with these events. The main therapeutic intervention is immunosuppressive therapy with corticoids. However, in some cases, or in case of delayed intervention, they may be fatal.

PURPOSE

Therefore, it is of great importance to increase the physicians and patients knowledge of the possible complications of this promising treatment modality. It is essential to apply proper management and help patients engage positively to prevent these situations occurring. This study was supported by the following research programme of Ministry of Health of the Czech Republic - RVO (FNHK, 00179906). The author declares he has no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.

Selenium Incorporation to Amino Acids in Chlorella Cultures Grown in Phototrophic and Heterotrophic Regimes

Microalgae accumulate bioavailable selenium-containing amino acids (Se-AAs), and these are useful as a food supplement. While this accumulation has been studied in phototrophic algal cultures, little data exists for heterotrophic cultures. We have determined the Se-AAs content, selenium/sulfur (Se/S) substitution rates, and overall Se accumulation balance in photo- and heterotrophic Chlorella cultures. Laboratory trials revealed that heterotrophic cultures tolerate Se doses ∼8-fold higher compared to phototrophic cultures, resulting in a ∼2-3-fold higher Se-AAs content. In large-scale experiments, both cultivation regimes provided comparable Se-AAs content. Outdoor phototrophic cultures accumulated up to 400 μg g^-1 of total Se-AAs and exhibited a high level of Se/S substitution (5-10%) with 30-60% organic/total Se embedded in the biomass. A slightly higher content of Se-AAs and ratio of Se/S substitution was obtained for a heterotrophic culture in pilot-scale fermentors. The data presented here shows that heterotrophic Chlorella cultures provide an alternative for Se-enriched biomass production and provides information on Se-AAs content and speciation in different cultivation regimes.

Hepatic Injury Induced by a Single Dose of Nivolumab - a Case Report and Literature Review

BACKGROUND

The use of nivolumab in the treatment of metastatic melanoma has become well established during past years. Despite its undeniable efficacy, immune-related side effects may occur, including acute liver injury. Liver toxicity caused by nivolumab is usually observed as liver enzyme elevation with mild or no symptoms; further, there is limited information regarding any histopathological findings.

CASE

We report a case of a 38-year-old woman with metastatic melanoma who developed unusual nivolumab-induced hepatic injury after a single dose of nivolumab. A liver biopsy was performed to assess the aetiology of hepatic lesions as no other analysis concerning biochemistry, virology, autoantibodies, nor imaging studies revealed any pathology. The histopathological analysis showed an oedema in the portal fields and mixed inflammation consisting of eosinophilic and neutrophilic granulocytes. The major finding was a prominent, predominantly intracellular, cholestasis.

CONCLUSION

To our knowledge, no such histopathological pattern of liver injury has been described in relation to nivolumab therapy elsewhere. This type of liver injury shows higher resistance to corticosteroids, which may warrant upfront high-dose corticotherapy combined with other immunosuppressive agents, including mycophenolate mofetil. This case highlights a necessary awareness regarding immunotherapy-related adverse events, which could be severe and potentially life-threatening.

Effects of dietary fat source on lutein, zeaxanthin and total carotenoids content of the egg yolk in laying hens during the early laying period

1. The study was conducted to investigate the effects of different dietary levels of an unsaturated or saturated fat source and the effects of different dietary energy levels in laying hen diets on the carotenoid content of the egg yolk. 2. Seventy-two ISA Brown laying hens aged 22 weeks old were allocated, for a 10 week period, to three treatments: control diet (HE group) with a 3.4% supplemented fat containing 2.1% soybean and 1.3% palm oil as fat sources and a ratio of unsaturated to saturated fatty acid (u/s) of 3.33; a lowered energy diet with 2.4% supplemented fat containing 1.4% soybean and 1.0% palm oil and u/s of 3.41 (LE+high u/s); a lowered energy diet with 2.4% supplemented fat containing 0.5% soybean and 1.9% palm oil and a u/s of 2.39 (LE+low u/s). A marigold plant extract supplement was used as a source of lutein. 3. Performance parameters (feed consumption, feed conversion, body weight), egg production rate and egg quality parameters were similar between treatments. Dietary fat digestibility at the middle of the study period was not different. Egg yolk total fat content was similar in all treatments at the middle and at the end of the study period. 4. Lutein, zeaxanthin, cis-lutein and total carotenoids content were significantly lower in eggs produced from the LE+low u/s group compared to those from the HE and the LE+high u/s groups (P < 0.01 for all parameters). 5. It was concluded that feeding laying hens with a diet containing 1% less supplemented fat and a lower u/s ratio compared to a control diet and to a diet with 1% less supplemented fat with a higher u/s ratio resulted in a significant reduction of carotenoid expression in the egg yolk at the end of experimental period. Performance and egg quality parameters were not affected by treatments.

Extracellular polysaccharide produced by Chlorella vulgaris - Chemical characterization and anti-asthmatic profile

Microalgae are the lowest plant organisms producing a wide range of metabolites that make them interesting organisms for industrial applications. Cultivation of green microalgal species Chlorella vulgaris resulted a significant production of extracellular polysaccharide (EPS). Preliminary chemico-spectroscopic studies on EPS revealed its molecular profile, a complex primary structure consisting of six monosaccharide units occurring in both furano and pyrano forms, a high sugar binding variability and the presence of partially methylated derivatives of some sugar constituents. Biological activity tests showed that EPS caused significant bronchodilatory, anti-inflammatory and antitussive effects in test animals. Chlorella EPS appears to be a promising agent for the prevention of chronic airway inflammation, which is the basic pathogenic mechanism of many respiratory diseases, including bronchial asthma.

Mutant Wars2 gene in spontaneously hypertensive rats impairs brown adipose tissue function and predisposes to visceral obesity

Brown adipose tissue (BAT) plays an important role in lipid and glucose metabolism in rodents and possibly also in humans. Identification of genes responsible for BAT function would shed light on underlying pathophysiological mechanisms of metabolic disturbances. Recent linkage analysis in the BXH/HXB recombinant inbred (RI) strains, derived from Brown Norway (BN) and spontaneously hypertensive rats (SHR), identified two closely linked quantitative trait loci (QTL) associated with glucose oxidation and glucose incorporation into BAT lipids in the vicinity of Wars2 (tryptophanyl tRNA synthetase 2 (mitochondrial)) gene on chromosome 2. The SHR harbors L53F WARS2 protein variant that was associated with reduced angiogenesis and Wars2 thus represents a prominent positional candidate gene. In the current study, we validated this candidate as a quantitative trait gene (QTG) using transgenic rescue experiment. SHR-Wars2 transgenic rats with wild type Wars2 gene when compared to SHR, showed more efficient mitochondrial proteosynthesis and increased mitochondrial respiration, which was associated with increased glucose oxidation and incorporation into BAT lipids, and with reduced weight of visceral fat. Correlation analyses in RI strains showed that increased activity of BAT was associated with amelioration of insulin resistance in muscle and white adipose tissue. In summary, these results demonstrate important role of Wars2 gene in regulating BAT function and consequently lipid and glucose metabolism.

[Pilot Study on MicroRNAs as Biomarkers of Response to Sunitinib Treatment in Patients with Metastatic Renall Cell Carcinoma]

BACKGROUND

Renal cell carcinoma (RCC) accounts for 2-3% of all malignant tumours. Metastatic RCC (mRCC) is commonly treated with tyrosine kinase inhibitors (TKI). Effective TKIs administration can be achieved only by accurate prediction of therapeutical response. Therefore, the aim of this study was to analyse papers concerning predictive potential of microRNA (miRNA).

MATERIAL AND METHODS

We chose seven candidate miRNAs and analysed their expression on 44 patients divided into cohort with poor and good response to sunitinib treatment. Patients were divided into two groups according to progression-free survival. RNA from tissue samples was isolated and expression of selected miRNAs was measured using quantitative PCR with miRNA-specific TaqMan probes.

RESULTS

We successfully validated two miRNAs to be differentially expressed in responding and non-responding patients to sunitinib treatment. Other analysed miRNAs have not shown predictive potential.

CONCLUSION

From miRNAs studied so far, two miRNAs had predictive value according to present study.Key words: microRNA - renal cell carcinoma - sunitib The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Supported by Ministry of Health of the Czech Republic, grant No. 15-34678A. All rights reserved.Submitted: 19. 3. 2018Accepted: 20. 3. 2018.

The chemical profile and pharmacodynamic properties of extracellular Wollea saccata biopolymer

Microalgae organisms are of interest for many biotechnology applications due to the production of a wide range of biologically active compounds. Incubation of Wollea saccata in a large scale afforded a mucilaginous, high molecular weight biopolymer composed of carbohydrate, protein and phenolic compounds. Sugar moiety was rich in hexoses (60%) and 6-deoxyhexoses (31%), while only 9% of pentoses was identified. Methylation analysis revealed about 40 types of methylated sugar derivatives, suggesting a very complex structure of Wollea biopolymer. Pharmacological studies revealed new pharmacodynamic properties of cyanobacteria biopolymer, i.e. antitussive and bronchodilatory. Biopolymer was able to suppress the cough reflex induced by chemical tussigen, but its effect was lower than that of codeine, the strongest antitussive agent. The bronchodilatory effect was similar or higher than the effect of salbutamol, a bronchodilatory drug used in a clinical practice. In pharmacological studies, there were no signs of toxicity or side effects in the animals following administration of Wollea biopolymer.

The cyanobacterial metabolite nocuolin a is a natural oxadiazine that triggers apoptosis in human cancer cells

Oxadiazines are heterocyclic compounds containing N-N-O or N-N-C-O system within a six membered ring. These structures have been up to now exclusively prepared via organic synthesis. Here, we report the discovery of a natural oxadiazine nocuolin A (NoA) that has a unique structure based on 1,2,3-oxadiazine. We have identified this compound in three independent cyanobacterial strains of genera Nostoc, Nodularia, and Anabaena and recognized the putative gene clusters for NoA biosynthesis in their genomes. Its structure was characterized using a combination of NMR, HRMS and FTIR methods. The compound was first isolated as a positive hit during screening for apoptotic inducers in crude cyanobacterial extracts. We demonstrated that NoA-induced cell death has attributes of caspase-dependent apoptosis. Moreover, NoA exhibits a potent anti-proliferative activity (0.7-4.5 μM) against several human cancer lines, with p53-mutated cell lines being even more sensitive. Since cancers bearing p53 mutations are resistant to several conventional anti-cancer drugs, NoA may offer a new scaffold for the development of drugs that have the potential to target tumor cells independent of their p53 status. As no analogous type of compound was previously described in the nature, NoA establishes a novel class of bioactive secondary metabolites.

[Non-specific immunotherapy inhibits angiogenesis - results of the monitoring of serum levels of vascular endothelial growth factor and matrix metalloproteinase 8 in patients with malignant melanoma receiving adjuvant high-dose interferon therapy]

OBJECTIVE

Interestingly, evidence is currently emerging that the activation of angiogenesis leads to immunomodulatory/immunosuppressive effects both at the local and systemic levels. These are very complex and interconnected processes. In this study, our aim was to establish interferon alpha-2b as an anti-angiogenic agent and show the complexity of angiogenesis and immunomodulation through the serum levels of vascular endothelial growth factor (VEGF) and matrix metalloproteinase 8 (MMP-8) in high-risk resected malignant melanoma before and after adjuvant therapy with high-dose interferon alpha-2b (HDI). Clinical outcomes of patients were also evaluated.

MATERIAL AND METHODS

We prospectively measured the serum levels of VEGF and MMP-8 by ELISA in 29 patients with high-risk resected malignant melanoma receiving adjuvant HDI. Blood samples were collected before and within one week after the treatment.

RESULTS

To see the results clearly, we divided our patients into two groups. The first group of patients whose VEGF serum level decreased after HDI (66%) showed long-term complete remission. The mean VEGF serum level in these patients decreased from 779.4 pg/ml to 446.2 pg/ml. This downward trend in VEGF was statistically significant. The second group of patients who did not show a decrease in VEGF serum level after HDI (34%) had no clinical benefit from the treatment. The mean VEGF serum levels in group 2 patients were 408 pg/ml before the treatment and 500 pg/ml after HDI. Results for MMP-8 were ambivalent.

CONCLUSIONS

Non-specific immunotherapy with interferons reduces angiogenesis. Our results are in line with the current view of the interconnection and complexity of angiogenesis and immunomodulation/immunosuppression. Non-specific immunotherapy with interferons disrupts the immunosup-pressive effect of the angiogenesis on the development of immune response against tumours and supports anti-tumour response in both direct and indirect way. The interference of HDI with the activation of angiogenesis and tumour progression could explain good clinical outcomes of patients with a decrease in serum VEGF. The outcomes of MMP-8 are inconclusive, its role remain unclear, and MMP-8 does not seem to function as a tumour suppressor.

[The Role of BRAF/MEK Inhibition in Metastatic Malignant Melanoma - a Case Study]

BACKGROUND

Metastatic malignant melanoma belongs to a group of cancers with high mortality. In recent years, advances in our knowledge of the pathogenesis of melanoma and the discovery of new drugs has resulted in significant progress in the treatment of metastatic malignant melanoma patients. The development of resistance to these drugs, however, remains a challenge. One way how to avoid resistance, or at least delay it, is to administer combination therapy.

OBSERVATION AND CONCLUSION

This case study demonstrates that combination therapy with a BRAF and a MEK inhibitor can be used to successfully treat metastatic malignant melanoma patients and suggests they should be employed in therapeutic algorithms for patients with metastatic malignant melanoma and BRAF gene mutations.

A liquid chromatography-mass spectrometric method for the detection of cyclic β-amino fatty acid lipopeptides

Bacterial lipopeptides, which contain β-amino fatty acids, are an abundant group of bacterial secondary metabolites exhibiting antifungal and/or cytotoxic properties. Here we have developed an LC-HRMS/MS method for the selective detection of β-amino fatty acid containing cyclic lipopeptides. The method was optimized using the lipopeptides iturin A and puwainaphycin F, which contain fatty acids of similar length but differ in the amino acid composition of the peptide cycle. Fragmentation energies of 10-55eV were used to obtain the amino acid composition of the peptide macrocycle. However, fragmentation energies of 90-130eV were used to obtain an intense fragment specific for the β-amino fatty acid (CnH2n+2N(+)). The method allowed the number of carbons and consequently the length of the β-amino fatty acid to be estimated. We identified 21 puwainaphycin variants differing in fatty acid chain in the crude extract of cyanobacterium Cylindrospermum alatosporum using this method. Analogously 11 iturin A variants were detected. The retention time of the lipopeptide variants showed a near perfect linear dependence (R(2)=0.9995) on the length of the fatty acid chain in linear separation gradient which simplified the detection of minor variants. We used the method to screen 240 cyanobacterial strains and identified lipopeptides from 8 strains. The HPLC-HRMS/MS method developed here provides a rapid and easy way to detecting novel variants of cyclic lipopeptides.

Cytotoxicity evaluation of large cyanobacterial strain set using selected human and murine in vitro cell models

The production of cytotoxic molecules interfering with mammalian cells is extensively reported in cyanobacteria. These compounds may have a use in pharmacological applications; however, their potential toxicity needs to be considered. We performed cytotoxicity tests of crude cyanobacterial extracts in six cell models in order to address the frequency of cyanobacterial cytotoxicity to human cells and the level of specificity to a particular cell line. A set of more than 100 cyanobacterial crude extracts isolated from soil habitats (mainly genera Nostoc and Tolypothrix) was tested by MTT test for in vitro toxicity on the hepatic and non-hepatic human cell lines HepG2 and HeLa, and three cell systems of rodent origin: Yac-1, Sp-2 and Balb/c 3T3 fibroblasts. Furthermore, a subset of the extracts was assessed for cytotoxicity against primary cultures of human hepatocytes as a model for evaluating potential hepatotoxicity. Roughly one third of cyanobacterial extracts caused cytotoxic effects (i.e. viability<75%) on human cell lines. Despite the sensitivity differences, high correlation coefficients among the inhibition values were obtained for particular cell systems. This suggests a prevailing general cytotoxic effect of extracts and their constituents. The non-transformed immortalized fibroblasts (Balb/c 3T3) and hepatic cancer line HepG2 exhibited good correlations with primary cultures of human hepatocytes. The presence of cytotoxic fractions in strongly cytotoxic extracts was confirmed by an activity-guided HPLC fractionation, and it was demonstrated that cyanobacterial cytotoxicity is caused by a mixture of components with similar hydrophobic/hydrophilic properties. The data presented here could be used in further research into in vitro testing based on human models for the toxicological monitoring of complex cyanobacterial samples.

[Possible Pitfalls of Ipilimumab Therapy in Malignant Melanoma - a Case Report]

BACKGROUND

Metastatic melanoma is a malignancy with one of the highest mortality rates. However, with the introduction of new drugs during the last decade, the prognosis of patients began to improve. Ipilimumab is one of the first so  called modern drugs in melanoma treatment. The therapy is often complicated by adverse effects which are referred as immunerelated adverse events due to its mechanism of action.

CASE

We present a case of 68-year- old women with metastatic melanoma who underwent treatment with ipilimumab. The patient encountered several adverse events during the treatment. Some of them are quite common (e.g. skin affections), others (e.g. endocrinopathies) are less frequent.

CONCLUSION

This case study highlights the need for close observation not only during the actual treatment with ipilimumab, but also several weeks or months after the last dose. This case study also demonstrates further need of education of doctors who do not usually come in to contact with such patients.

Adverse effects of AMP-activated protein kinase alpha2-subunit deletion and high-fat diet on heart function and ischemic tolerance in aged female mice

AMP-activated protein kinase (AMPK) plays a role in metabolic regulation under stress conditions, and inadequate AMPK signaling may be also involved in aging process. The aim was to find out whether AMPK alpha2-subunit deletion affects heart function and ischemic tolerance of adult and aged mice. AMPK alpha2(-/-) (KO) and wild type (WT) female mice were compared at the age of 6 and 18 months. KO mice exhibited subtle myocardial AMPK alpha2-subunit protein level, but no difference in AMPK alpha1-subunit was detected between the strains. Both alpha1- and alpha2-subunits of AMPK and their phosphorylation decreased with advanced age. Left ventricular fractional shortening was lower in KO than in WT mice of both age groups and this difference was maintained after high-fat feeding. Infarct size induced by global ischemia/reperfusion of isolated hearts was similar in both strains at 6 months of age. Aged WT but not KO mice exhibited improved ischemic tolerance compared with the younger group. High-fat feeding for 6 months during aging abolished the infarct size-reduction in WT without affecting KO animals; nevertheless, the extent of injury remained larger in KO mice. The results demonstrate that adverse effects of AMPK alpha2-subunit deletion and high-fat feeding on heart function and myocardial ischemic tolerance in aged female mice are not additive.

Separation of Aeruginosin-865 from Cultivated Soil Cyanobacterium (Nostoc sp.) by Centrifugal Partition Chromatography combined with Gel Permeation Chromatography

Aeruginosin-865 was isolated from cultivated soil cyanobacteria using a combination of centrifugal partition chromatography (CPC) and gel permeation chromatography. The solubility of Aer-865 in different solvents was evaluated using the conductor-like screening model for real solvents (COSMO-RS). The CPC separation was performed in descending mode with a biphasic solvent system composed of water-n-BuOH-acetic acid (5:4:1, v/v/v). The upper phase was used as a stationary phase, whereas the lower phase was employed as a mobile phase at a flow rate of 10 mL/min. The revolution speed and temperature of the separation column were 1700 rpm and 25 degrees C, respectively. Preparative CPC separation followed by gel permeation chromatography was performed on 50 mg of crude extract yielding Aer-865 (3.5 mg), with a purity over 95% as determined by HPLC. The chemical identity of the isolated compound was confirmed by comparing its spectroscopic data (UV, HRESI-MS, HRESI-MS/MS) with those of an authentic standard and data available in the literature.

[Adverse effects of modern treatment of malignant melanoma and their treatment/ management]

BACKGROUND

Malignant melanoma belongs to the most deadly human tumours and despite all preventive programs its incidence continues to rise. Until 2011, chemotherapy was the only therapeutic option for inoperable or metastatic disease in the Czech Republic. However, new treatment modalities (e. g. targeted therapy) have been introduced recently.

AIM

Since most of the modern drugs are still available only in clinical trials, the aim of this article is to provide a brief and comprehensive review of current treatment options for metastatic disease. The attention is focused on their potential side effects, so that doctors who do not usually deal with these drugs would get acquainted with them. This could contribute to a prompt management of associated symptoms or an early referral of the patient to an appropriate clinical centre without undue delay.

Tick saliva increases production of three chemokines including monocyte chemoattractant protein-1, a histamine-releasing cytokine

The effect of Ixodes ricinus tick saliva on the production of various cytokines and chemokines by mouse splenocytes was tested by a cytokine array. We demonstrated a strong upregulation of three chemokines, monocyte chemoattractant protein-1 (MCP-1), thymus-derived chemotactic agent 3 (TCA-3) and macrophage inflammatory protein 2 (MIP-2). MCP-1 could be induced by tick saliva itself. While TCA-3 and MIP-2 are engaged in Th2 polarization of the host immune response associated with tick feeding, MCP-1 may act as a histamine release factor, increasing blood flow into the feeding lesion thus facilitating tick engorgement in the late, rapid feeding phase.

Tick salivary cystatin sialostatin L2 suppresses IFN responses in mouse dendritic cells

Type I interferon (IFN), mainly produced by dendritic cells (DCs), is critical in the host defence against tick-transmitted pathogens. Here, we report that salivary cysteine protease inhibitor from the hard tick Ixodes scapularis, sialostatin L2, affects IFN-β mediated immune reactions in mouse dendritic cells. Following IFN receptor ligation, the Janus activated kinases/signal transducer and activator of transcription (JAK/STAT) pathway is activated. We show that sialostatin L2 attenuates phosphorylation of STATs in spleen dendritic cells upon addition of recombinant IFN-β. LPS-stimulated dendritic cells release IFN-β which in turn leads to the induction of IFN-stimulated genes (ISG) through JAK/STAT pathway activation. The induction of two ISG, interferon regulatory factor 7 (IRF-7) and IP-10, was suppressed by sialostatin L2 in LPS-stimulated dendritic cells. Finally, the interference of sialostatin L2 with IFN action led to the enhanced replication of tick-borne encephalitis virus in DC. In summary, we present here that tick salivary cystatin negatively affects IFN-β responses which may consequently increase the pathogen load after transmission via tick saliva.

Potential and limits of Raman spectroscopy for carotenoid detection in microorganisms: implications for astrobiology

In this paper, it is demonstrated how Raman spectroscopy can be used to detect different carotenoids as possible biomarkers in various groups of microorganisms. The question which arose from previous studies concerns the level of unambiguity of discriminating carotenoids using common Raman microspectrometers. A series of laboratory-grown microorganisms of different taxonomic affiliation was investigated, such as halophilic heterotrophic bacteria, cyanobacteria, the anoxygenic phototrophs, the non-halophilic heterotrophs as well as eukaryotes (Ochrophyta, Rhodophyta and Chlorophyta). The data presented show that Raman spectroscopy is a suitable tool to assess the presence of carotenoids of these organisms in cultures. Comparison is made with the high-performance liquid chromatography approach of analysing pigments in extracts. Direct measurements on cultures provide fast and reliable identification of the pigments. Some of the carotenoids studied are proposed as tracers for halophiles, in contrast with others which can be considered as biomarkers of other genera. The limits of application of Raman spectroscopy are discussed for a few cases where the current Raman spectroscopic approach does not allow discriminating structurally very similar carotenoids. The database reported can be used for applications in geobiology and exobiology for the detection of pigment signals in natural settings.

A hybrid non-ribosomal peptide/polyketide synthetase containing fatty-acyl ligase (FAAL) synthesizes the β-amino fatty acid lipopeptides puwainaphycins in the Cyanobacterium Cylindrospermum alatosporum

A putative operon encoding the biosynthetic pathway for the cytotoxic cyanobacterial lipopeptides puwainphycins was identified in Cylindrospermum alatosporum. Bioinformatics analysis enabled sequential prediction of puwainaphycin biosynthesis; this process is initiated by the activation of a fatty acid residue via fatty acyl-AMP ligase and continued by a multidomain non-ribosomal peptide synthetase/polyketide synthetase. High-resolution mass spectrometry and nuclear magnetic resonance spectroscopy measurements proved the production of puwainaphycin F/G congeners differing in FA chain length formed by either 3-amino-2-hydroxy-4-methyl dodecanoic acid (4-methyl-Ahdoa) or 3-amino-2-hydroxy-4-methyl tetradecanoic acid (4-methyl-Ahtea). Because only one puwainaphycin operon was recovered in the genome, we suggest that the fatty acyl-AMP ligase and one of the amino acid adenylation domains (Asn/Gln) show extended substrate specificity. Our results provide the first insight into the biosynthesis of frequently occurring β-amino fatty acid lipopeptides in cyanobacteria, which may facilitate analytical assessment and development of monitoring tools for cytotoxic cyanobacterial lipopeptides.

Novel Aeruginosin-865 from Nostoc sp. as a potent anti-inflammatory agent

Aeruginosin-865 (Aer-865), isolated from terrestrial cyanobacterium Nostoc sp. Lukešová 30/93, is the first aeruginosin-type peptide containing both a fatty acid and a carbohydrate moiety, and is the first aeruginosin to be found in the genus Nostoc. Mass spectrometry, chemical and spectroscopic analysis as well as one- and two-dimensional NMR and chiral HPLC analysis of Marfey derivatives were applied to determine the peptidic sequence: D-Hpla, D-Leu, 5-OH-Choi, Agma, with hexanoic and mannopyranosyl uronic acid moieties linked to Choi. We used an AlphaLISA assay to measure the levels of proinflammatory mediators IL-8 and ICAM-1 in hTNF-α-stimulated HLMVECs. Aer-865 showed significant reduction of both: with EC50 values of (3.5±1.5) μg mL(-1) ((4.0±1.7) μM) and (50.0±13.4) μg mL(-1) ((57.8±15.5) μM), respectively. Confocal laser scanning microscopy revealed that the anti-inflammatory effect of Aer-865 was directly associated with inhibition of NF-κB translocation to the nucleus. Moreover, Aer-865 did not show any cytotoxic effect.

Effect of tick saliva on immune interactions between Borrelia afzelii and murine dendritic cells

Interaction between mouse dendritic cells (DCs) and Borrelia afzelii spirochetes was monitored on three different levels: phagocytosis of spirochetes by DCs, production of cytokines by Borrelia-stimulated DCs and the ability of Borrelia-exposed DCs to activate specific CD4+ T lymphocytes. The effect of Ixodes ricinus tick saliva on each of these interactions was examined. Tick saliva was shown to decrease the number of phagocytosing DCs. The ability of Borrelia-exposed DCs to induce both proliferation and IL-2 production by specific CD4+ T cells was significantly reduced by tick saliva. And surprisingly, we have shown an inhibitory effect of tick saliva on the production of both Th1 (TNF-α and IL-6) and Th2 (IL-10) cytokines by DCs. Our data reveal a complex inhibitory effect of tick saliva on Borrelia-DCs interaction.

[Changes in immune reactivity in cancer patients]

It appears that the long-accepted paradigm that cytostatic and radiation therapy cause only immunosuppression, is not so clearly true. With regard to new knowledge in cancer immunology field, it seems that not only cytostatic and radiation therapy plays an important role in the alteration of immune system. There are many other factors influencing immunity like tumour environment itself, the use of immunomodulatory drugs or even the mental condition of cancer patients. The aim of review is to familiarize physicians with possible alterations of the immune system in cancer patients.

Cytotoxicity and secondary metabolites production in terrestrial Nostoc strains, originating from different climatic/geographic regions and habitats: is their cytotoxicity environmentally dependent?

Extensive selection of cyanobacterial strains (82 isolates) belonging to the genus Nostoc, isolated from different climatic regions and habitats, were screened for both their secondary metabolite content and their cytotoxic effects to mammalian cell lines. The overall occurrence of cytotoxicity was found to be 33%, which corresponds with previously published data. However, the frequency differs significantly among strains, which originate from different climatic regions and microsites (particular localities). A large fraction of intensely cytotoxic strains were found among symbiotic strains (60%) and temperate and continental climatic isolates (45%); compared with the less significant incidences in strains originating from cold regions (36%), deserts (14%), and tropical habitats (9%). The cytotoxic strains were not randomly distributed; microsites that clearly had a higher occurrence of cytotoxicity were observed. Apparently, certain natural conditions lead to the selection of cytotoxic strains, resulting in a high cytotoxicity occurrence, and vice versa. Moreover, in strains isolated from a particular microsite, the cytotoxic effects were caused by different compounds. This result supports our hypothesis for the environmental dependence of cytotoxicity. It also contradicts the hypothesis that clonality and lateral gene transfer could be the reason for this phenomenon. Enormous variability in the secondary metabolites was detected within the studied Nostoc extracts. According to their molecular masses, only 26% of these corresponded to any known structures; thus, pointing to the high potential for the use of many terrestrial cyanobacteria in both pharmacology and biotechnology.

Cytotoxicity and Pro-Apoptotic Activity of 2,2´-Bis[4,5-bis(4-hydroxybenzyl)-2-(4-hydroxyphenyl)cyclopent-4-en-1,3-dione], a Phenolic Cyclopentenedione Isolated from the Cyanobacterium Strain Nostoc sp. str. Lukešová 27/97

The cytotoxicity of the polyphenol 2,2´-bis[4,5-bis(4-hydroxybenzyl)-2-(4-hydroxyphenyl)cyclopent-4-en-1,3-dione], nostotrebin 6 (NOS-6), was tested under in vitro conditions using mouse fibroblasts (BALB/c cells). Identification of NOS-6 and its uptake into fibroblasts was examined by multi-stage mass spectrometry analysis with the following fragmentation pattern: MS (m/z) [M+H]⁺ 799.1 → MS² 399.1 → MS³ 305.1 → MS⁴ 277.1. Using several cell viability assays, the IC₅₀ of NOS-6 after 24 h incubation was found to be 8.48 ± 0.16/12.15 ± 1.96 µM (neutral red/MTT assay) which was higher than that of doxorubicin. It was found that NOS-6 is capable of inducing both types of cell death, apoptosis and necrosis in a dose-dependent manner. The biological activities of the cyclopentenediones and preliminary data on NOS-6 cytotoxicity are discussed.

Extracellular glycoconjugates produced by cyanobacterium Wollea saccata

In order to survive in a highly competitive environment, freshwater or marine phototrophic microorganisms have to develop defense strategies that result in a tremendous diversity of compounds from different metabolic pathways. Recent trends in drug research from natural sources have shown that algae and cyanobacteria are promising organisms to furnish novel biochemically active compounds. In this study, we have analysed the extracellular mucilaginous proteoglycan produced by fresh-water heterocytous filamentous cyanobacterium Wollea saccata, strain Hindák 2000/18. This mucilaginous material is an acidic proteoglycan containing 30% protein and 52% carbohydrates on the basis of fraction dry weight. The constituent sugars of the carbohydrate component include glucose, fucose, 3-O-methylfucose, xylose, galactose, 3-O-methylgalactose, mannose, rhamnose, arabinose and glucuronic acid. The extracellular proteoglycan has been separated into five fractions (WF1-WF5) by anion exchange chromatography. Individual polymeric fractions varied in protein (16-57%) and carbohydrate (31-66%) contents, and in the composition of constituent monosaccharides.

[High-dose interferon alpha in treatment of patients with malignant melanoma, monitoring of predictive and prognostic biomarkers]

BACKGROUNDS

The incidence of malignant melanoma is increasing by about 2-5% per year, exceeding an incidence of all other tumors. Adjuvant immunotherapy with high-dose interferon (HDI) as per the ECOG 1684 trial Kirkwood's schema is still recommended as a standard. HDI should be started within 60 days after a surgical procedure. Meaningful adjuvant immunotherapy is based on radical surgical excision, an investigation of the sentinel node and regional lymph node dissection, if indicated. Current research aims to utilize routinely usable biomarkers in order to define patients who would explicitly profit from HDI.

DESIGN

The authors present a review of HDI trials, focusing on the management of adverse effects of HDI and on biomarkers. This review also discusses the initial own experiences at the Oncology Centre in Hradec Králové.

CONCLUSION

Malignant melanoma is a very immunogenic tumour. Immunotherapy with HDI is considered to be the only therapeutic modality so far that has been proven to prolong relapse-free survival and overall survival (in short-time criterion) in adjuvant setting. However, the results of these trials are inconsistent and particular biomarkers of therapeutic response have not been defined yet.

[Palliative cancer care within the Hradec Králové Region Health Care System: own experience]

Palliative cancer care is an active treatment and nursing intervention in patients in whom cancer therapy has been withdrawn due to untreatable progression of the cancer disease. The main aim of palliative cancer care is to ensure the best possible quality of life of a cancer patient and the patient's family members. Palliative cancer care is provided in two basic forms, general and specialized. In the present paper, the authors discuss palliative cancer care and its implementation into clinical practice with reference to their own experience in providing this care.

[NK cells, chemokines and chemokine receptors]

NK cells are an important component of natural immunity, which provides a defence response against viruses, bacterial and parasitic intracellular pathogens and tumour cells. NK cells are capable of rapid responses without prior sensitization and cytotoxic response is independent of the presence of the antigens of the major histocompatibility system. NK cells produce a number of cytokines (e.g. INF-gamma, GM-CSF and TNF-beta) and chemokines and in this way they regulate both the natural and acquired immune response. By contrast, NK cells are regulated both positively and negatively by cytokines and chemokines produced by other immune cells. Attention is focused on the possibility of influencing the tumour process by using cytokine- and chemokine-activated NK cells. In studies in mice models as well as in several clinical trials, it has been shown that the presence of cytotoxic cells in tumour stroma is associated with a more favourable prognosis of cancer.There is also plenty of evidence that in tumour stroma a number of cytokines and chemokines are produced which may have ambivalent effects.

Selected Adipokines - Plasma Concentrations and Adipose Tissue Expressions during 24-Hour Lipid Infusion in Healthy Men

Our aim was to assess the reaction of TNFα, resistin, leptin and adiponectin to lipid infusion. Eight healthy subjects underwent a 24-hour lasting infusion of lipid emulsion. Plasma concentrations and expressions of selected cytokines in subcutaneous fat were measured. TNFα plasma concentration did not change during the first 4 hours of hypertriglyceridemia, but a significant increase after 24 hours was detected (p<0.001 for 0; 30; 240 min vs. 24 h). Plasma concentration of resistin significantly increased at 30 min of infusion and remained elevated (p<0.01 for 0 min vs. 30; 240 min; p<0.001 for 0 min vs. 24 h). Plasma concentrations of leptin and adiponectin did not show any significant changes. Although the expression of resistin in the subcutaneous adipose tissue tended to increase, the change was not significant. Expressions of TNFα, leptin and adiponectin were unaffected. In conclusions, our results indicate that acutely induced hyperlipidemia could influence the secretion of TNFα and resistin.

Modulation of type I iodothyronine 5'-deiodinase activity in white adipose tissue by nutrition: possible involvement of leptin

Adipose tissue is an important target for thyroid hormones (TH). However, the metabolism of TH in white adipose tissue is poorly characterized. Our objective was to describe possible changes in activities of TH-metabolizing enzymes in white adipose tissue, and the role of TH metabolism in the tissue during obesogenic treatment, caloric restriction and in response to leptin in mice. Activity of type I iodothyronine 5'-deiodinase (D1) in white fat was stimulated by a high-fat diet, which also increased plasma leptin levels, while brown adipose tissue D1 activity did not change. Caloric restriction decreased the activity of D1 in white fat (but not in the liver), reduced leptin levels, and increased the expression of stearoyl CoA desaturase 1 (SCD-1), a marker and mediator of the effect of leptin on tissue metabolism. Leptin injections increased D1 activity and down-regulated SCD-1 in white fat. Our results demonstrate changes in D1 activity in white adipose tissue under the conditions of changing adiposity, and a stimulatory effect of leptin on D1 activity in the tissue. These results suggest a functional role for D1 in white adipose tissue, with D1 possibly being involved in the control of adipose tissue metabolism and/or accumulation of the tissue.