Proteomic analysis of blood cells in fish exposed to chemotherapeutics: evidence for long term effects

Skin mucus and blood plasma as non-lethal sources of malnutrition protein biomarkers in meagre (Argyrosomus regius)

Developing dietary formulations for aquaculture that meet nutritional requirements is essential to production, as nutrition is key for fish growth and health. However, novel dietary formulations may induce malnutrition, which is complex to evaluate and often requires animal sacrifice. Therefore, finding reliable non-lethal biomarkers to diagnose malnutrition in fish is important. This study aimed to obtain vital information on potential non-lethal biomarkers from blood plasma and skin mucus to assess the fish's nutritional status using meagre (Argyrosomus regius) juveniles. For that purpose, a nutritional challenge was performed with fish fed a fish meal (FM) and fish-oil (FO) based control diet (55.1 % FM; 11 % FO, CTRL), a challenging diet (15 % FM; 7 % FO, CD), and a highly challenging diet (5 % FM; 5 % FO, ED), which, despite being nutritionally complete, may pose digestive and physiological challenges to carnivorous species. Diets significantly affected blood parameters, except for leukocyte counts, peroxidase activity, and immunoglobulin levels. Overall, blood parameters showed potential as non-lethal biomarkers to accurately identify signs of malnutrition. Meagre's plasma and skin mucus proteomes provided crucial information on the species' reaction to malnutrition, and 29 proteins connected to various physiological functions such as metabolism, development and immunity showed potential as non-lethal biomarkers. SIGNIFICANCE: The significance of this study lies in the establishment of potential non-lethal biomarkers for diagnosing malnutrition in fish. The results demonstrate that immunological, haematological, and biochemical parameters measured in fish blood can reveal signs of nutritional deficiencies. The findings further highlight that the proteomes of plasma and skin mucus provide valuable information about the fish's nutritional status. Notably, 29 proteins identified in this study, associated with various physiological functions, exhibit biomarker potential and warrant consideration in future research in the field of aquaculture nutrition. Moreover, the research provides critical insights into the proteome of meagre (Argyrosomus regius), enhancing our understanding of the species and contributing to the future improvement of its aquaculture production.

Automated Hematological Approach and Protein Electrophoretic Pattern in Tilapia (Oreochromis niloticus): An Innovative and Experimental Model for Aquaculture

This study aimed to assess the usefulness of two innovative automated methods (automated blood count counters and flow cytometry) for hematological investigation in Tilapia to make a contribution to the clinical diagnostics of this farmed species. Moreover, serum total proteins and their electrophoretic fractions (prealbumin, albumin, α-, β-, and γ-fraction), as health condition indicators, were assessed. The analysis of serum total proteins and electrophoretic fraction showed a normal and typical electrophoretic pattern of healthy fish (serum total proteins, 3.70 ± 0.62 g/dL; prealbumin, 0.44 ± 0.20 g/dL; albumin, 1.17 ± 0.66 g/dL; α-fraction, 1.49 ± 0.64 g/dL; β-fraction, 0.32 ± 0.16 g/dL; and γ-fraction, 0.29 ± 0.13 g/dL). The relationships between the values of red blood cells (RBCs), white blood cells (WBCs), and thrombocytes (TCs) obtained with the two automated methods were determined using Pearson correlation analysis. The results showed a significant positive correlation between automatic blood cell counting and flow cytometry analysis for RBCs (r = 0.97, p < 0.0001) and WBCs (r = 0.91, p < 0.0001), whereas no correlation was found for TCs (r = -0.11, p = 0.66). The preliminary results gathered in this study seem to highlight the usefulness of the new analytical techniques herein investigated in tilapia, suggesting their application in the hematological investigation of farmed fish species and their usefulness for monitoring the health and well-being of fish reared in aquaculture.

DIGE Analysis of Fish Tissues

Two-dimensional difference gel electrophoresis (2D-DIGE) appears to be especially useful in quantitative approaches, allowing the co-separation of proteins of control samples and proteins of treated/disease samples on the same gel, eliminating gel-to-gel variability. The principle of 2D-DIGE is to label proteins prior to isoelectric focusing and use three spectrally resolvable fluorescent dyes, allowing the independent labeling of control and experimental samples. This procedure makes it possible to reduce the number of gels in an experiment, allowing the accurate and reproducible quantification of multiple samples. 2D-DIGE has been found to be an excellent methodical tool in several areas of fish research, including environmental pollution and toxicology, the mechanisms of development and disorders, reproduction, nutrition, evolution, and ecology.

Cu(I) complexes as new antiproliferative agents against sensitive and doxorubicin resistant colorectal cancer cells: synthesis, characterization, and mechanisms of action

Cancer is one of the worst health issues worldwide, representing the second leading cause of death. Current chemotherapeutic drugs face some challenges like the acquired resistance of the tumoral cells and low specificity leading to unwanted side effects. There is an urgent need to develop new compounds that may target resistant cells. The synthesis and characterization of two Cu(i) complexes of general formula [Cu(PP)(LL)][BF4], where PP is a phosphane ligand (triphenylphosphine or 1,2-bis(diphenylphosphano) ethane) and LL = is a heteroaromatic bidentate ligand (4,4'-dimethyl-2,2'-bipyridine and 6,3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine). The new compounds were fully characterized by spectroscopic techniques (NMR, FTIR and UV-vis.), elemental analysis (C, H, N and S) and two structures were determined by single X-ray diffraction studies. The antiproliferative potential of the new Cu(i) complexes were studied in tumor (breast adenocarcinoma, ovarian carcinoma and in colorectal carcinoma sensitive and resistant to doxorubicin) and normal (fibroblasts) cell lines. Complexes 1-4 did not show any antiproliferative potential. Amongst the complexes 5-8, complex 8 shows high cytotoxic potential against colorectal cancer sensitive and resistant to doxorubicin and low cytotoxicity towards healthy cells. We show that complexes 5-8 can cleave pDNA and, in particular, the in vitro pDNA cleavage is due to an oxidative mechanism. This oxidative mechanism corroborates the induction of reactive oxygen species (ROS), that triggers HCT116 cell death via apoptosis, as proved by the increased expression of BAX protein relative to BCL-2 protein and the depolarization of mitochondrial membrane potential, and via autophagy. Additionally, complex 8 can block the cell cycle in the G1 phase, also exhibiting a cytostatic potential. Proteomic analysis confirmed the apoptotic, autophagic and cytostatic potential of complex 8, as well as its ability to produce ROS and cause DNA damage. The interference of the complex in folding and protein synthesis and its ability to cause post-translational modifications was also verified. Finally, it was observed that the complex causes a reduction in cellular metabolism. The results herein demonstrated the potential of Cu(i) complexes in targeting doxorubicin sensitive and resistant cells which is positive and must be further explored using in vivo animal models.

High-Precision and Low-Cost Wireless 16-Channel Measurement System for Malachite Green Detection

Focusing on the issue of the malachite green traditional test methods such as large volume, high cost and high complex, this paper proposed a novel multi-channel electrochemical malachite green detection system. Specific recognition properties of malachite green DNA adapter is employed to realize accurate sensing of concentration of malachite green, which can achieve precise detection of malachite green concentration with low noise and high precision. The maximum measurement capability of multi-channel acquisition system is 16 samples in a batch. According to the experimental results, malachite green could be detected quantitatively in the range from 10⁻³ μg/mL to 10 μg/mL, which performs well in the test of malachite green residues in aquatic product transportation.

DIGE Analysis of Fish Tissues

Two-dimensional difference gel electrophoresis (2D-DIGE) appears to be especially useful in quantitative approaches, allowing the co-separation of proteins of control samples from proteins of treatment/disease samples on the same gel, eliminating gel-to-gel variability. The principle of 2D-DIGE is to label proteins prior to isoelectric focusing and use three spectrally resolvable fluorescent dyes, allowing the independent labeling of control and experimental samples. This procedure makes it possible to reduce the number of gels in an experiment, allowing the accurate and reproducible quantification of multiple samples. 2D-DIGE has been found to be an excellent methodical tool in several areas of fish research, including environmental pollution and toxicology, the mechanisms of development and disorders, reproduction, nutrition, evolution, and ecology.

Toxic textile dyes accumulate in wild European eel Anguilla anguilla

Dyes are used to stain inks, paints, textile, paper, leather and household products. They are omnipresent, some are toxic and may threaten our environment, especially aquatic ecosystems. The presence of residues of sixteen dyes (triarylmethanes, xanthenes, phenothiazines and phenoxazines) and their metabolites was analyzed in muscle tissue samples of individual yellow-phased European eels (Anguilla anguilla) from 91 locations in Belgian rivers, canals and lakes sampled between 2000 and 2009 using ultra performance liquid chromatography-tandem mass spectrometry. Eel was contaminated by dyes in 77% of the sites. Malachite Green, Crystal Violet and Brilliant Green were present in 25-58% of the samples. Dye occurrence was related to the distribution of textile and dye production industries. This field study is the first large-scale survey to document the occurrence of artificial dyes in wildlife. Considering the annual amounts of dyes produced worldwide and the unintentional spillage during their use, our observations warrant additional research in other parts of the world. The presence of these highly toxic dyes in the European eel may form an additional threat to this critically endangered species. The contaminated eels should be considered as not suitable for consumption.

Characterization of antiproliferative potential and biological targets of a copper compound containing 4'-phenyl terpyridine

Several copper complexes have been assessed as anti-tumor agents against cancer cells. In this work, a copper compound [Cu(H2O){OS(CH3)2}L](NO3)2 incorporating the ligand 4'-phenyl-terpyridine antiproliferative activity against human colorectal, hepatocellular carcinomas and breast adenocarcinoma cell lines was determined, demonstrating high cytotoxicity. The compound is able to induce apoptosis and a slight delay in cancer cell cycle progression, probably by its interaction with DNA and induction of double-strand pDNA cleavage, which is enhanced by oxidative mechanisms. Moreover, proteomic studies indicate that the compound induces alterations in proteins involved in cytoskeleton maintenance, cell cycle progression and apoptosis, corroborating its antiproliferative potential.

Proteomic analysis of epidermal mucus from sea lice-infected Atlantic salmon, Salmo salar L

Health diets that contain immunostimulants and other functional ingredients can strengthen the immune response in Atlantic salmon, Salmo salar, and thereby reduce sea lice, Lepeophtheirus salmonis, infection levels. Such diets can be used to supplement other treatments and will potentially reduce the need for delousing and medication. A sea lice infection trial was conducted on fish with an average weight of 215 g. One control diet and four experimental diets containing functional ingredients were produced. The diets were fed to salmon for 4 weeks before infection with sea lice copepodids. When lice had developed to chalimus III/IV, 88 fish per diet were examined for lice loads. Mucus samples from fish fed the different diets were taken before and after lice infection. Mass spectrometry-based proteomics was used to characterize the protein composition in the epidermal mucus of Atlantic salmon and to identify quantitative alterations in protein expression. Multivariate analysis of the generated data sets was performed to identify protein biomarkers. Putative biomarkers associated with functional feed intake and with sea lice infection have been identified and can form the basis for strategic validation experiments with selected functional feeds.