Physiological and Transcriptional Effects of Mixtures of Environmental Estrogens, Androgens, Progestins, and Glucocorticoids in Zebrafish.

Fishes are exposed to mixtures of different classes of steroids, but ecotoxicological implications are not sufficiently known. Here, we systematically analyze effects of different combinations of steroid mixtures in zebrafish embryos to assess their joint activities on physiology and transcriptional alterations of steroid-specific target genes at 96 and 120 h post fertilization. In binary mixtures of clobetasol propionate (CLO) with estradiol (E2) or androstenedione (A4), each steroid exhibited its own expression profile.

Effects of the glucocorticoid clobetasol propionate and its mixture with cortisol and different class steroids in adult female zebrafish.

Ecotoxicological effects of glucocorticoids and steroid mixtures in the environment are not sufficiently known. Here we investigate effects of 11-14 days exposure of female zebrafish to the glucocorticoid clobetasol propionate (Clo), cortisol (Cs), their mixture and mixtures with five different class steroids (Clo + triamcinolone + estradiol + androstenedione + progesterone) in liver, brain and gonads. Cs showed little activity, while Clo reduced the condition factor at 0.

Environmental glucocorticoids corticosterone, betamethasone and flumethasone induce more potent physiological than transcriptional effects in zebrafish embryos.

Many glucocorticoids occur in the aquatic environments but their adverse effects to fish are poorly known. Here we investigate effects of the natural glucocorticoid corticosterone and the synthetic glucocorticoids betamethasone and flumethasone in zebrafish embryos. Besides studying the effects of each steroid, we compared effects of natural with synthetic glucocorticoids, used as drugs.

Active Glucocorticoids Have a Range of Important Adverse Developmental and Physiological Effects on Developing Zebrafish Embryos.

Glucocorticoids in aquatic systems originating from natural excretion and medical use may pose a risk to fish. Here, we analyzed physiological and transcriptional effects of clobetasol propionate (CLO), cortisol and cortisone in zebrafish embryos as single compounds and binary mixtures. CLO and cortisol, but not cortisone showed a concentration-dependent decrease in muscle contraction, increase in heart rate, and accelerated hatching.

Anti-Inflammatory Activity of Cyanobacterial Serine Protease Inhibitors Aeruginosin 828A and Cyanopeptolin 1020 in Human Hepatoma Cell Line Huh7 and Effects in Zebrafish (Danio rerio).

Intensive growth of cyanobacteria in freshwater promoted by eutrophication can lead to release of toxic secondary metabolites that may harm aquatic organisms and humans. The serine protease inhibitor aeruginosin 828A was isolated from a microcystin-deficient Planktothrix strain. We assessed potential molecular effects of aeruginosin 828A in comparison to another cyanobacterial serine protease inhibitor, cyanopeptolin 1020, in human hepatoma cell line Huh7, in zebrafish embryos and liver organ cultures.

Comparative effects of nodularin and microcystin-LR in zebrafish: 1. Uptake by organic anion transporting polypeptide Oatp1d1 (Slco1d1).

Microcystin-LR (MC-LR) and nodularin are hepatotoxins produced by several cyanobacterial species. Their toxicity is based on active cellular uptake and subsequent inhibition of protein phosphatases PP1/2A, leading to hyperphosphorylation and cell death. To date, uptake of MC-LR and nodularin in fish is poorly understood.

Comparative effects of nodularin and microcystin-LR in zebrafish: 2. Uptake and molecular effects in eleuthero-embryos and adult liver with focus on endoplasmic reticulum stress.

Microcystin (MC) and nodularin are structurally similar cyanobacterial toxins that inhibit protein phosphatases. Additional modes of action are poorly known, in particular for nodularin. In our associated work, we showed that active cellular uptake is mediated by the organic anion transporting polypeptide drOatp1d1 in zebrafish (Faltermann et al.

Preparation of Fluorescent Microcystin Derivatives by Direct Arginine Labelling and Their Biological Evaluation.

Microcystin is the most prevalent toxin produced by cyanobacteria and poses a severe threat to livestock, humans and entire ecosystems. We report the preparation of a series of fluorescent microcystin derivatives by direct arginine labelling of the unprotected peptides at the guanidinium side chain. This new method allows a simple late-stage diversification strategy for native peptides devoid of protecting groups under mild conditions.

Molecular effects of the cyanobacterial toxin cyanopeptolin (CP1020) occurring in algal blooms: global transcriptome analysis in zebrafish embryos.

Higher water temperatures due to climate change combined with eutrophication of inland waters promote cyanobacterial blooms. Some of the cyanobacteria produce toxins leading to drinking water contamination and fish poisoning on a global scale. Here, we focused on the molecular effects of the cyanobacterial oligopeptide cyanopeptolin CP1020, produced by Microcystis and Planktothrix strains, by means of whole-genome transcriptomics.