Cd-induced apoptosis through the mitochondrial pathway in the hepatopancreas of the freshwater crab Sinopotamon henanense

Effects of cadmium exposure on metabolism, antioxidant defense, immune function, and the hepatopancreas transcriptome of Cipangopaludina cathayensis

Cadmium (Cd) is a common contaminant in aquatic environments. However, little is known about the mechanisms underlying Cd toxicity in the freshwater snail Cipangopaludina cathayensis (Heude, 1890). This study to investigate the toxic effects of Cd on the standard metabolism, antioxidant activities, immune function, and hepatopancreas transcriptome profiles of C. cathayensis. C. cathayensis was exposed to 0.25, 0.5, 1.0, or 1.5 mg/L Cd for 3 h, with results showing that Cd significantly inhibited oxygen consumption and ammonia excretion and disrupted the respiratory metabolism of C. cathayensis. In addition, the O:N ratio dropped below 7, indicating that C. cathayensis may rely exclusively on proteins as an energy source under Cd stress. To understand how Cd impacts the antioxidant activities, immune function, and transcriptional profiles, C. cathayensis were exposed to 0.5 (low exposure, L14) or 1.5 (high exposure, H14) mg/L Cd for 14 days. Our results indicate that Cd exposure leads to oxidative stress and immunosuppression, with the latter effect being larger for exposure to higher Cd concentrations. A total of 2172 differentially expressed genes (DEGs) were identified by transcriptome analysis of the hepatopancreas, of which 885 were upregulated and 1287 were downregulated. Gene ontology and KEGG analyses revealed that the DEGs in the H14 group are enriched for energy generation terms and the "oxidative phosphorylation" pathway, respectively. Therefore, up-regulation of energy metabolism may be an adaptive strategy under Cd stress. Moreover, several genes involved in antioxidant activity were downregulated, whereas genes related to reactive oxygen species generation were upregulated. In addition, many immunity-related genes were identified within the DEGs, indicating that Cd toxicity may affect immune defense. Further, DEGs in the H14 group were enriched for disease-associated pathways. Taken together, our results indicate that Cd exposure leads to metabolic disorders, oxidative stress, and immunosuppression and thus may potentially contribute to disease outbreaks.

Transgenic RFP-RPS-30UbL strain of the nematode Caenorhabditis elegans as a biomonitor for environmental pollutants

Environmental pollutants are recognized as one of the major concerns for public health. The free-living nematode Caenorhabditis elegans are widely used to evaluate the toxicity of environmental contaminants in biomonitoring researches. In the present study, a new transgenic strain, rps-30^-/- ;RFP-RPS-30^UbL was generated, with constitutively active rps-30 promoter used to control the expression of RFP-RPS-30^UbL fusion protein. We found RFP-RPS-30^UbL would accumulate to form 'rod-like' structures, when worms were exposed to environmental contaminants, including Cd, Hg, Pb, As, Paraquat and Dichlorvos. The number of the 'rod-like' structures was induced by environmental contaminants in a concentration- and time-dependent manner. The 'rod-like' structure formation could be detectable in response to the concentration of each contaminant as low as 24-h LC50 × 10^-7 , and the detectable time could be within 2 h. Detecting the transcription and expression levels of RFP-RPS-30^UbL in worms exposed to different kinds of environmental contaminants showed that the expression level of RFP-RPS-30^UbL was not regulated by environmental contaminants, and the number differences of 'rod-like' structures were just due to the morphological change of RFP-RPS-30^UbL from dispersion to accumulation induced by environmental contaminants. In addition, this transgenic strain was developed in rps-30^-/- homozygous worm, which was a longevity strain. Detection of lifespan and brood size showed that rps-30^-/- ;RFP-RPS-30^UbL transgenic worm was more suitable to be cultured and used further than N2;GFP-RPS-30^UbL , for expressing RPS-30^UbL in wild type N2 worms shortened the lifespan and deceased the brood size. Therefore, rps-30^-/- ;RFP-RPS-30^UbL transgenic worm might play a potential role in versatile environmental biomonitoring, with the advantage of not only the convenient and quick fluorescence-based reporter assay, but also the quantificational evaluation of the toxicities of environmental contaminants using 'rod-like' structures with high sensitivity, off-limited the expression level of the reporter protein.

Fungicidal Action of the Triphenylphosphonium-Driven Succinate Dehydrogenase Inhibitors Is Mediated by Reactive Oxygen Species and Suggests an Effective Resistance Management Strategy

Succinate dehydrogenase (SDH) is an effective target of SDH inhibitor (SDHI) fungicides which received more and more attention in recent years. However, there is no good solution to their rapidly growing drug resistance caused by frequent use. In this study, three triphenylphosphonium (TPP)-conjugated boscalid analogues were synthesized and tested for antifungal activities. They all, especially 2c, exhibited enhanced fungicidal activity and broader spectra compared to boscalid. The action mechanism study revealed that 2c was also an SDH inhibitor acting on the Qp site. However, the rapid accumulation of 2c in mitochondria because of TPP-targeting triggered reactive oxygen species burst in mitochondria, resulting in irreversible damage to the mitochondrial structure and function. Thus, 2c made the fungicidal activity output mode changing from mainly relying on ATP production inhibition (as traditional SDHIs) to significant damage of the cell structure and functions. This mechanism change made it difficult for plant pathogenic fungi to develop resistance to 2c and its analogues, which was of great significance for the increasingly challenging management of field resistance to SDHI fungicides.

Cloning, Functional Characterization and Response to Cadmium Stress of the Thioredoxin-like Protein 1 Gene from Phascolosoma esculenta

Cadmium (Cd) is a heavy metal toxicant and is widely distributed in aquatic environments. It can cause excessive production of reactive oxygen species (ROS) in the organism, which in turn leads to a series of oxidative damages. Thioredoxin (Trx), a highly conserved disulfide reductase, plays an important role in maintaining the intracellular redox homeostasis in eukaryotes and prokaryotes. Phascolosoma esculenta is an edible marine worm, an invertebrate that is extensively found on the mudflats of coastal China. To explore the molecular response of Trx in mudflat organisms under Cd stress, we identified a new Trx isoform (Trx-like protein 1 gene) from P. esculenta for the first time, designated as PeTrxl. Molecular and structural characterization, as well as multiple sequence and phylogenetic tree analysis, demonstrated that PeTrxl belongs to the Trx superfamily. PeTrxl transcripts were found to be ubiquitous in all tissues, and the highest expression level occurred in the coelomic fluid. Exposure to three sublethal concentrations of Cd resulted in the upregulation and then downregulation of PeTrxl expression levels over time in coelomic fluid of P. esculenta. The significant elevation of PeTrxl expression after 12 and 24 h of Cd exposure at 6 and 96 mg/L, respectively, might reflect its important role in the resistance to Cd stress. Recombinant PeTrxl (rPeTrxl) showed prominent dose-dependent insulin-reducing and ABTS free radical-scavenging abilities. After exposure to 96 mg/L Cd for 24 h, the ROS level increased significantly in the coelomic fluid, suggesting that Cd induced oxidative stress in P. esculenta. Furthermore, the injection of rPeTrxl during Cd exposure significantly reduced the ROS in the coelomic fluid. Our data suggest that PeTrxl has significant antioxidant capacity and can protect P. esculenta from Cd-induced oxidative stress.

From field to plate: Agricultural pesticide presence in the guayas estuary (Ecuador) and commercial mangrove crabs

Mangroves are unique coastal ecosystems, located in tropical and subtropical regions. Yet, the functioning of these essential ecosystems is threatened by the presence of pollutants, including pesticides originating from agricultural activities. We investigated pesticide residues in the Guayas estuarine environment, since agricultural activities rapidly increased in the Guayas river basin over the past decades. A multi-residue analysis involving a selection of 88 pesticides was performed on the white meat and the hepatopancreas of the red mangrove crab (Ucides Occidentalis) at 15 sampling sites within the Guayas estuary along with water, sediment, and leaves samples. We found that 35 active compounds were present in the Guayas estuary, of which pyrimethanil was most commonly detected and had the highest concentrations in almost all compartments. Also, cadusafos was present in all studied compartments of the Guayas mangrove system and several prohibited pesticides (including carbendazim, carbofuran, and parathion) were detected. An ecotoxicological and probabilistic consumer risk assessment pointed out that current butachlor, carbendazim, and fludioxonil concentrations can cause adverse effects in aquatic organisms in the long term. Moreover, high potential acute and chronic risks of cadusafos residues on aquatic invertebrates and of diuron on algae in the Guayas wetlands were observed. Still, the exposure results indicated that the health risk for the consumers of the commercial red mangrove crab is low concerning cadusafos, chlorpyrifos, diuron, linuron, and pyrimethanil residues in crab tissues. The findings presented in this research can provide a useful basis for local water managers and environmental conservation groups to act and reduce the usage of pesticides, to avoid threatening aquatic and human health.

Effects of cadmium on antioxidant and non-specific immunity of Macrobrachium nipponense

As a non-essential and toxic element, cadmium poses an important threat to aquatic organisms and human food safety. In this study, the effects of cadmium on antioxidant and non-specific immunity of Macrobrachium nipponense were studied from the physiological and biochemical indexes, histology and expression of related genes. These results showed that low concentrations (0.01, 0.02 mg/L) of cadmium have a positive effect on the non-specific immunity of M. nipponense, but high concentration (0.04 mg/L) of cadmium could inhibit or even damage the non-specific immunity of M. nipponense. The cadmium could induce oxidative stress in M. nipponense, and M. nipponense actived the antioxidant defense system to deal with oxidative stress, but high concentration (0.04 mg/L) of cadmium could inhibit the antioxidant defense system of M. nipponense, leading to oxidative damage, and may induce apoptosis in severe case. At the same time, the results of histology showed that cadmium can damage the structure of gill and hepatopancreas tissues of M. nipponense. This study provides theoretical data for evaluating the influences of heavy metal cadmium on M. nipponense and the toxic mechanism of heavy metal cadmium.

From Mangrove to Fork: Metal Presence in the Guayas Estuary (Ecuador) and Commercial Mangrove Crabs

Mangrove wetlands provide essential ecosystem services such as coastal protection and fisheries. Metal pollution due to industrial and agricultural activities represents an issue of growing concern for the Guayas River Basin and related mangroves in Ecuador. Fisheries and the related human consumption of mangrove crabs are in need of scientific support. In order to protect human health and aid river management, we analyzed several elements in the Guayas Estuary. Zn, Cu, Ni, Cr, As, Pb, Cd, and Hg accumulation were assessed in different compartments of the commercial red mangrove crab Ucides occidentalis (hepatopancreas, carapax, and white meat) and the environment (sediment, leaves, and water), sampled at fifteen sites over five stations. Consistent spatial distribution of metals in the Guayas estuary was found. Nickel levels in the sediment warn for ecological caution. The presence of As in the crabs generated potential concerns on the consumers' health, and a maximum intake of eight crabs per month for adults is advised. The research outcomes are of global importance for at least nine Sustainable Development Goals (SDGs). The results presented can support raising awareness about the ongoing contamination of food and their related ecosystems and the corresponding consequences for environmental and human health worldwide.

Effects of Different Ammonia Levels on Tribenuron Methyl Toxicity in Daphnia magna

The present study investigates the toxicity of the herbicide tribenuron methyl (TBM) as an anthropogenic agent and ammonia as an abiotic factor on Daphnia magna at environmentally relevant concentrations. These stressors may coexist in surface waters in agricultural regions. To achieve this objective, D. magna were exposed to TBM at a nominal concentration of 0.81 μg/L in association with a low ammonia (LA) concentration of 0.65 mg/L and a high ammonia (HA) concentration of 1.61 mg/L in acute toxicity tests of 96-h duration and chronic toxicity tests of 21-day duration. The D. magna also were exposed to TBM, HA, and LA singly. The D. magna were analysed for various biomarkers of sublethal toxicity. Glutathione peroxidase (GPx), glutathione S-transferase (GST), cholinesterase (ChE) enzyme activities, and levels of thiobarbituric acid reactive substances (TBARS) and total protein were determined spectrophotometrically. Mitochondrial membrane potential (MMP) was analysed by microscopy with fluorescence staining. Cytochrome c and 5' AMP-activated protein kinase (AMPK) were analysed by Western blotting. Morphometric properties were examined microscopically. This is the first study in which AMPK, an indicator of intracellular energy, was measured in D. magna. GST and ChE enzyme activities and TBARS and total protein levels did not change during acute exposures (i.e., 96 h) in all treatments. GPx activity increased in D. magna from the HA + TBM treatment compared with single-exposure groups. The level of cytochrome c protein was elevated in D. magna from the LA and LA + TBM treatments. AMPK protein levels increased in all treatments with daphnids, except in the LA group. MMP was depolarised in D. magna from all treatments, whereas the most notable change was observed in HA + TBM mixture group in chronic exposures. The results show that GST and ChE may not be sensitive biomarkers for evaluating the sublethal toxic effects to D. magna exposed to environmentally relevant concentrations of ammonia and TBM. Acute and chronic exposure to ammonia and TBM probably caused an energetic crisis in D. magna. Therefore, AMPK and MMP are promising biomarkers for these toxicants.

Effect of cadmium on essential metals and their impact on lipid metabolism in Saccharomyces cerevisiae

Cadmium (Cd) is a toxic heavy metal that induces irregularity in numerous lipid metabolic pathways. Saccharomyces cerevisiae, a model to study lipid metabolism, has been used to establish the molecular basis of cellular responses to Cd toxicity in relation to essential minerals and lipid homeostasis. Multiple pathways sense these environmental stresses and trigger the mineral imbalances specifically calcium (Ca) and zinc (Zn). This review is aimed to elucidate the role of Cd toxicity in yeast, in three different perspectives: (1) elucidate stress response and its adaptation to Cd, (2) understand the physiological role of a macromolecule such as lipids, and (3) study the stress rescue mechanism. Here, we explored the impact of Cd interference on the essential minerals such as Zn and Ca and their influence on endoplasmic reticulum stress and lipid metabolism. Cd toxicity contributes to lipid droplet synthesis by activating OLE1 that is essential to alleviate lipotoxicity. In this review, we expanded our current findings about the effect of Cd on lipid metabolism of budding yeast.

Identification and profiling of microRNAs responsive to cadmium toxicity in hepatopancreas of the freshwater crab Sinopotamon henanense

Background

Cadmium (Cd) is a ubiquitous environmental toxicant for aquatic animals. The freshwater crab, Sinopotamon henanense (S. henanense), is a useful model for monitoring Cd exposure since it is widely distributed in sediments whereby it tends to accumulate several toxicants, including Cd. In the recent years, the toxic effects of Cd in the hepatopancreas of S. henanense have been demonstrated by a series of biochemical analysis and ultrastructural observations as well as the deep sequencing approaches and gene expression profile analysis. However, the post-transcriptional regulatory network underlying Cd toxicity in S.henanense is still largely unknown.

Results

The miRNA transcriptional profile of the hepatopancreas of S. henanense was used to investigate the expression levels of miRNAs in response to Cd toxicity. In total, 464 known miRNAs and 191 novel miRNAs were identified. Among these 656 miRNAs, 126 known miRNAs could be matched with the miRNAs of Portunus trituberculatus, Eriocheir sinensis and Scylla paramamosain. Furthermore, a total of 24 conserved miRNAs were detected in these four crab species. Fifty-one differentially expressed miRNAs were identified in the Cd-exposed group, with 31 up-regulated and 20 down-regulated. Eight of the differentially expressed miRNAs were randomly selected and verified by the quantitative real-time PCR (qRT-PCR), and there was a general consistency (87.25%) between the qRT-PCR and miRNA transcriptome data. A total of 5258 target genes were screened by bioinformatics prediction. GO term analysis showed that, 17 GO terms were significantly enriched, which were mainly related to the regulation of oxidoreductase activity. KEGG pathway analysis showed that 18 pathways were significantly enriched, which were mainly associated with the biosynthesis, modification and degradation of proteins.

Conclusion

In response to Cd toxicity, in the hepatopancreas of S. henanense, the expressions of significant amount of miRNAs were altered, which may be an adaptation to resist the oxidative stress induced by Cd. These results provide a basis for further studies of miRNA-mediated functional adaptation of the animal to combat Cd toxicity.

Roles of three Es-Caspases during spermatogenesis and Cadmium-induced apoptosis in Eriocheir sinensis

Functions of Caspases remain obscure in Crustacea. We studied the existence and participations of apoptosis-related factors in Eriocheir sinensis testis. Three Es-Caspases (Es-Caspase 3/ 7/ 8) in E. sinensis were cloned and characterized. We observed that three es-caspases mRNA had specific expression patterns during spermiogenesis, with weak signal around the nucleus and invaginated acrosomal vesicle in early-stage spermatids, became stronger in middle-stage, finally focused on the acrosomal tube and nucleus in mature sperm. We then investigated the immunostaining intensity and positional alterations of Es-Caspase 3, Es-Caspase 8 and p53 during spermatogenesis, which were correlated with the differential tendencies of cells to undergo apoptosis and specific organelles shaping processes. After apoptotic induction by Cadmium, Es-Caspase 8 increased gradually, while Es-Caspase 3 increased firstly and then decreased, Es-p53 initially decreased and then increased. These results implies that Es-Caspase 3/ Es-Caspase 8/ p53 may play roles in Cadmium-induced apoptosis during spermatogenesis, and Caspase 8-Caspase 3-p53 pathway may interact with extrinsic or intrinsic pathways to regulate the destiny of sperm cells. Our study revealed the indispensable roles of Caspases during spermatogenesis and the possible molecular interactions in response to the Cadmium-induced apoptosis in E. sinensis, which filled the gap of apoptotic mechanisms of crustacean.

Cell damage and apoptosis in the hepatopancreas of Eriocheir sinensis induced by cadmium

Cadmium (Cd) is one of the most common pollutants in the environment and it is known to cause a range of tissue damages and apoptosis in invertebrates. In this study, we investigated the effect of Cd on the hepatopancreas of the crab Eriocheir sinensis, a commercially and ecologically important species of crustacean. The crabs were first exposed to water containing different concentrations of Cd²⁺ (0, 0.63, 1.26, 2.52, 5.04 and 10.07mg/L) for 6days. Typical morphological characteristics and physiological changes of apoptosis were then observed using various methods, including AO/EB double fluorescence staining, transmission electron microscopy and DNA fragmentation analysis. The results showed that Cd²⁺ induced cell damage and apoptosis in a concentration-dependent manner. Transmission electron microscopy revealed the presence of cellular swelling and necrosis with reduced number of microvilli on the cell surface and damages to individual organelles. The mitochondria became swollen and vacuolated. The rough endoplasmic reticulum (Rer) was expanded, with membrane rupture and many different sizes of vesicles, suggesting the destruction of protein-synthesizing structures in the hepatopancreatic cells. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidases (GPx) initially increased and subsequently decreased with increasing Cd²⁺ concentrations. This was accompanied by increases in malondialdehyde (MDA) and H₂O₂ contents, which led to membrane lipid peroxidation. Crabs exposed to Cd²⁺ also displayed significant increases in caspase-3, -8, and -9 activities compared to control crabs. Cadmium induced the production and accumulation of ROS in the hepatopancreas, which resulted in oxidative damage and abnormal metabolism. Taken together, the results indicated that Cd²⁺ could induce oxidative damage as well caspase-dependent apoptosis in E. sinensis hepatopancreas.

Antagonistic effects of selenium on cadmium-induced apoptosis by restoring the mitochondrial dynamic equilibrium and energy metabolism in chicken spleens

The aim of this study was to investigate the mechanism of cadmium-induced apoptosis in chicken spleens and the antagonistic effects of selenium. We duplicated the selenium-cadmium interaction model and examined the expression of apoptosis-, immune-, mitochondrial dynamics- and energy metabolism-related genes. The results demonstrated that after treatment with cadmium, the frequency of apoptosis was significantly increased, and the morphological characteristics of apoptosis were observed. The expression of pro-apoptotic genes was increased, and that of anti-apoptotic genes was decreased. The mRNA levels of tumor necrosis factor-α and interlenkin-1β were observably increased, but the interlenkin-2 and interferon-γ levels were markedly decreased. Furthermore, the mRNA and protein levels of dynamin-related protein 1 and mitochondrial fission factor were significantly enhanced, whereas mitofusin 1, mitofusin 2, and optic atrophy 1 were markedly decreased. The expression of hexokinase 1, hexokinase 2, aconitase 2, lactate dehydrogenase A, lactate dehydrogenase B, succinatedehydrogenase B, pyruvate kinase and phosphofructokinase were also reduced. Selenium supplements remarkably attenuated cadmium-induced effects (p < 0.05). Based on the above results, conclude that the cadmium treatment promoted a mitochondrial dynamic imbalance and reduced energy metabolism, leading to apoptosis and immune dysfunction in chicken spleens, and selenium had an antagonistic effect on Cd-induced apoptosis.

Cadmium induced oxidative damage and apoptosis in the hepatopancreas of Meretrix meretrix

Even trace amounts of cadmium (Cd), a non-essential metal, are known to be toxic to aquatic organisms. Here we investigated the relationship between cadmium ion (Cd(2+)) exposure and oxidative damage and apoptosis in the hepatopancreas of the clam Meretrix meretrix. Clams were exposed to different concentrations of Cd(2+) (0, 1.5, 3, 6 and 12 mg L(-1)) for 5 days. We monitored both antioxidant enzyme activity, including that of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx), and levels of malondialdehyde (MDA), glutathione (GSH) and glutathione disulfide (GSSG). Apoptosis of hepatopancreatic cells was detected by DNA laddering and AO/EB double fluorescent staining. The results show that the rate of apoptotis, MDA levels, and caspase-3 activity, increased with Cd(2+) concentration, whereas GPx activity and the ratio of GSH/GSSG, decreased. SOD and CAT enzyme activity first increased, then decreased, with increasing Cd(2+) concentration; peak activity of these enzymes was recorded in the 3 mg L(-1) Cd(2+)-treatment group. These results show that Cd-induced oxidative damage can both induce, and aggravate, apoptosis in the hepatopancreatic cells of clams, even at Cd(2+) concentrations far below the semi-lethal dose for adult clams. The observed changes in caspase-3 activity enhanced significantly at lower Cd(2+) concentrations, indicating that caspase-3 is a suitable biomarker for heavy metal pollution, especially cadmium pollution, in marine organisms.

Transcriptome assembly and expression profiling of molecular responses to cadmium toxicity in hepatopancreas of the freshwater crab Sinopotamon henanense

Cadmium (Cd) pollution is a serious global problem, which causes irreversible toxic effects on animals. Freshwater crab, Sinopotamon henanense, is a useful environmental indicator since it is widely distributed in benthic habitats whereby it tends to accumulate Cd and other toxicants. However, its molecular responses to Cd toxicity remain unclear. In this study, we performed transcriptome sequencing and gene expression analyses of its hepatopancreas with and without Cd treatments. A total of 7.78 G clean reads were obtained from the pooled samples, and 68,648 unigenes with an average size of 622 bp were assembled, in which 5,436 were metabolism-associated and 2,728 were stimulus response-associated that include 380 immunity-related unigenes. Expression profile analysis demonstrated that most genes involved in macromolecular metabolism, oxidative phosphorylation, detoxification and anti-oxidant defense were up-regulated by Cd exposure, whereas immunity-related genes were down-regulated, except the genes involved in phagocytosis were up-regulated. The current data indicate that Cd exposure alters gene expressions in a concentration-dependent manner. Therefore, our results provide the first comprehensive S.henanense transcriptome dataset, which is useful for biological and ecotoxicological studies on this crab and its related species at molecular level, and some key Cd-responsive genes may provide candidate biomarkers for monitoring aquatic pollution by heavy metals.

Structural and functional changes in the zebrafish (Danio rerio) skeletal muscle after cadmium exposure

This report describes the alterations induced by an environmentally realistic concentration of cadmium in skeletal muscle fibre organization, composition, and function in the teleost zebrafish. Results demonstrate that the ion induces a significant quantitative and qualitative deterioration, disrupting sarcomeric pattern and altering glycoprotein composition. These events, together with a mitochondrial damage, result in a significant reduction in swimming performance. In conclusion, the evidence here collected indicate that in presence of an environmental cadmium contamination, important economic (yields in fisheries/aquaculture), consumer health (fish is an important source of proteins), and ecological (reduced fitness due to reduced swimming performance) consequences can be expected.

An integrated study on Gammarus elvirae (Crustacea, Amphipoda): perspectives for toxicology of arsenic-contaminated freshwater

The Italian region Latium is characterized by extensive quaternary volcanic systems that contribute greatly to arsenic (As) contamination of freshwater, including drinking water supplies. However, knowledge of the possible toxic effects in these aquatic environments is, despite being highly relevant to public health, still limited. In this paper, we approach this issue using Gammarus elvirae, an amphipod species that inhabits rivers and streams in central Italy, including Latium. We explored the possibility of using G. elvirae in the toxicology of freshwater by addressing the most relevant issues. First, we tested the usefulness of hemocytes from G. elvirae in determining non-specific DNA damage by means of the Comet assay after exposure (24 h and 7 days) to different river water samples in Latium; second, we provided an interpretative overview of the usefulness of hepatopancreatic epithelial cells of G. elvirae as a means of assessing toxicity after long-term exposure to As and other pollutants; third, the LC (50-240 h) value for G. elvirae was estimated for arsenate, which is usually the dominant arsenic species in surface waters. Our study sheds light on G. elvirae at different levels, providing a background for future toxicological research of freshwater.

L-Aminoacid Oxidase from Bothrops leucurus Venom Induces Nephrotoxicity via Apoptosis and Necrosis

Acute renal failure is a common complication caused by Bothrops viper envenomation. In this study, the nefrotoxicity of a main component of B. leucurus venom called L-aminoacid oxidase (LAAO-Bl) was evaluated by using tubular epithelial cell lines MDCK and HK-2 and perfused kidney from rats. LAAO-Bl exhibited cytotoxicity, inducing apoptosis and necrosis in MDCK and HK-2 cell lines in a concentration-dependent manner. MDCK apoptosis induction was accompanied by Ca2+ release from the endoplasmic reticulum, reactive oxygen species (ROS) generation and mitochondrial dysfunction with enhanced expression of Bax protein levels. LAAO-Bl induced caspase-3 and caspase-7 activation in both cell lines. LAAO-Bl (10 μg/mL) exerts significant effects on the isolated kidney perfusion increasing perfusion pressure and urinary flow and decreasing the glomerular filtration rate and sodium, potassium and chloride tubular transport. Taken together our results suggest that LAAO-Bl is responsible for the nephrotoxicity observed in the envenomation by snakebites. Moreover, the cytotoxic of LAAO-Bl to renal epithelial cells might be responsible, at least in part, for the nephrotoxicity observed in isolated kidney.