Effect of copper ions on hematological and cytogenetic parameters of freshwater fishes Carassius auratus gibelio

Effects of Copper Exposure on Oxidative Stress, Apoptosis, Endoplasmic Reticulum Stress, Autophagy and Immune Response in Different Tissues of Chinese Mitten Crab (Eriocheir sinensis)

High concentrations of copper (Cu²⁺) pose a great threat to aquatic animals. However, the mechanisms underlying the response of crustaceans to Cu²⁺ exposure have not been well studied. Therefore, we investigated the alterations of physiological and molecular parameters in Chinese mitten crab (Eriocheir sinensis) after Cu²⁺ exposure. The crabs were exposed to 0 (control), 0.04, 0.18, and 0.70 mg/L of Cu²⁺ for 5 days, and the hemolymph, hepatopancreas, gills, and muscle were sampled. The results showed that Cu²⁺ exposure decreased the antioxidative capacity and promoted lipid peroxidation in different tissues. Apoptosis was induced by Cu²⁺ exposure, and this activation was associated with the mitochondrial and ERK pathways in the hepatopancreas. ER stress-related genes were upregulated in the hepatopancreas but downregulated in the gills at higher doses of Cu²⁺. Autophagy was considerably influenced by Cu²⁺ exposure, as evidenced by the upregulation of autophagy-related genes in the hepatopancreas and gills. Cu²⁺ exposure also caused an immune response in different tissues, especially the hepatopancreas, where the TLR2-MyD88-NF-κB pathway was initiated to mediate the inflammatory response. Overall, our results suggest that Cu²⁺ exposure induces oxidative stress, ER stress, apoptosis, autophagy, and immune response in E. sinensis, and the toxicity may be implicated following the activation of the ERK, AMPK, and TLR2-MyD88-NF-κB pathways.

Environmental pollution and toxic substances: Cellular apoptosis as a key parameter in a sensible model like fish

The industrial wastes, sewage effluents, agricultural run-off and decomposition of biological waste may cause high environmental concentration of chemicals that can interfere with the cell cycle activating the programmed process of cells death (apoptosis). In order to provide a detailed understanding of environmental pollutants-induced apoptosis, here we reviewed the current knowledge on the interactions of environmental chemicals and programmed cell death. Metals (aluminum, arsenic, cadmium, chromium, cobalt, zinc, copper, mercury and silver) as well as other chemicals including bleached kraft pulp mill effluent (BKME), persistent organic pollutants (POPs), and pesticides (organo-phosphated, organo-chlorinated, carbamates, phyretroids and biopesticides) were evaluated in relation to apoptotic pathways, heat shock proteins and metallothioneins. Although research performed over the past decades has improved our understanding of processes involved in apoptosis in fish, yet there is lack of knowledge on associations between environmental pollutants and apoptosis. Thus, this review could be useful tool to study the cytotoxic/apoptotic effects of different pollutants in fish species.

The Accumulation of Heavy Metals and Cytometric Characteristics Features of Red Blood Cells in Different Ages of Carp Fish from Zaporozhian Reservoir

The research was held in terms of Zaporozhian Reservoir (Ukraine) from 2014 till 2015 year. It was established that prussian carp (Carassius gibelio Bloch, 1782) and roach (Rutilus rutilus Linnaeus, 1758) underyearlings accumulate essential elements more extensively, especially zinc, comparing to adults ones. The species characteristic of heavy metals accumulation in the carp fish body was observed. The intensity level of erythropoiesis occurrence was higher in young fish of both species of carp fish. The specific features of cytometric characteristics of fish erythrocytes were identified: the relative amount of mature red blood cells prevailed in roach, and the area of mature red blood cells was significantly higher in prussian carp. In addition, in the young roach among immature forms of red blood cells significantly higher percentage of polychromatophil normoblasts was revealed.

Assessment of the state of the gibel carp Carassius auratus gibelio in the Amur River Basin: heavy-metal and arsenic concentrations and histopathology of internal organs

This study describes the concentrations of heavy metals and arsenic (As) and the basic histopathological changes in the internal organs of gibel carp Carassius auratus gibelio from five sites of the Amur River basin. Gibel carp from Sindinskaya Passage had the highest liver concentrations of zinc (Zn) (31.95 ± 13.443), copper (Cu) (12.52 ± 5.746), manganese (9.22 ± 8.121), and cadmium (0.37 ± 0.660 mg/kg wet weight [ww]) compared with fish captured from the Bol'shoi Ussuriiskii Island area and Kadi Lake; however, concentrations of nickel (0.22 ± 0.156 mg/kg ww) were not significantly different, and concentrations of lead (0.19 ± 0.121 mg/kg ww) were higher than those in fish from Kadi Lake. Mean concentrations of metals and As in muscles were lower than Russia's recommended limits for food products; however, concentrations of Cu, Zn, and Hg in individual fish were greater than the limit. Kidney disease was detected in 100% of sampled carp. Kidney disease was characterized by the formation of numerous granulomas in kidney tissues between the renal tubules. The degree of granulomatosis varied among sites. Granulomatous kidney disease in gibel carp is widespread in many reservoirs of the lower Amur River basin. The following histopathological changes were detected in liver: vacuolization of hepatocytes, hypertrophy of multiple hepatocytes, binuclearity, presence of numerous irregularly shaped nuclei in hepatocytes, karyopyknosis, diffuse necrosis of hepatocytes (in some cases focal), and edema. Necrotic changes in hepatocytes, which are important indices of the toxic effect of pollutants, were found in the majority of investigated carp from the lower Amur River basin. Some fish had simultaneous pathological alterations in multiple organs.