OXIDATIVE STRESS IN HUMAN THYROID GLAND UNDER IODINE DEFICIENCY NODULAR GOITER: FROM HARMLESSNESS TO HAZARD DEPENDING ON COPPER AND IODINE SUBCELLULAR DISTRIBUTION

Background. Thyroid disorders are the second most common endocrinopathies found in humans and animals. Determination of their key molecular markers presents a special interest.Objective. We studied iodine and copper accumulation in nodular, paranodular and contralateral (not affected tissue by node) tissues of human thyroid gland in relation to the level of metal-binding proteins, potential antioxidants, and oxidative changes in tissue for this goal. Lower level of organificated iodine and higher level and mass fraction of inorganic iodine and copper in the nodular and paranodular tissue versus contralateral part of thyroid gland was established.Results. The level of both metal-binding and apo-form of metallothioneins was higher. Content of reduced glutathione was lower in node-affected tissue compared to the contralateral part. Signs of oxidative stress (higher activity of superoxide dismutase, catalase, glutathione-transferase and level of oxyradicals) and cytotoxicity (higher cathepsin D activity, higher level of DNA strand breaks and glycolysis activation) in affected tissue were observed. The range of indice variability in paranodular tissue was smaller than in nodule compared to the parenchyma of contralateral part.Conclusions. Excess of copper unbound to metallothionein in goitrous-changed tissue and high level of inorganic iodine could be the reason for elevated DNA fragmentation and increased lysosomal membrane permeability and activation of antioxidant defense. The main criterions of goiter formation were represented by low level of organificated iodine and high level of DNA damage in thyroid gland.KEY WORDS: iodine deficiency nodular colloidal goiter, iodine, copper, metallothioneins, oxidative stress, cytotoxicit

Biochemical responses of freshwater mussel Unio tumidus to titanium oxide nanoparticles, Bisphenol A, and their combination

The aim of the study was to evaluate the combined effect of two widespread xenobiotics, titanium oxide nanoparticles (TiO2) and bisphenol A (BPA), on freshwater bivalve Unio tumidus. The specimens were exposed for 14 days to TiCl4 (Ti, 1.25 µM), TiO2 (1.25 μM), BPA (0.88 nM), or their combination (TiO2+BPA). Every type of exposure resulted in a particular oxidative stress response: TiO2 had antioxidant effect, decreasing the generation of reactive oxygen species (ROS) and phenoloxidase (PhO) activity, and doubling reduced glutathione (GSH) concentration in the digestive gland; Ti caused oxidative changes by increasing levels of ROS, PhO and superoxide dismutase; BPA decreased the GSH level by a factor of two. In the co-exposure treatment, these indices as well as lysosomal membrane stability were not affected

BIOCHEMICAL RESPONSES OF THE DREISSENA POLYMORPHA FROM MUNICIPAL POND TO CAFFEINE, MICROPLASTICS, AND HEATING IN SINGLE AND COMBINED EXPOSURES

Pharmaceuticals have become the aquatic pollutantsof growing concern. Caffeine is one of the most widely distributed in thesurface waters among them. However, the environmentally relevantmodels of its effect, which include combined exposures with probableconfounding factors, are unknown. Microplastics are a suspected vectorthat influences caffeine bioavailability. The temperature dependence ofresponse, considering the increase of temperature in surface waters, canalso be anticipated. The aim of this study was to analyze the input ofcaffeine, microplastics and elevated temperature into their combinedeffect on the zebra mussel Dreissena polymorpha (Pallas, 1771)

Common and particular biochemical responses of Unio tumidus to herbicide, pharmaceuticals and their combined exposure with heating

The priority list of freshwater pollutants is increasingly amended by pharmaceuticals. Their impact on the aquatic biota can be modulated by the presence of typical pollutants, like pesticides, and/or abnormal heating. The aim of this study was to elucidate potentially hazardous impact of combined environmental factors on the freshwater mussels by analysing various sets of biochemical markers. We treated the bivalve molluscs of Unio tumidus with non-steroidal anti-inflammatory drug diclofenac (Dc, 2 nM), calcium antagonist and antihypertensive drug nifedipine (Nf, 2 nM) or organophosphonate glyphosate-based herbicide Roundup MAX (Rn, 79 nM of glyphosate) at 18oC as well as with the mixture of these substances at 18oC (Mix) or 25oC (MixT) during 14 days. The concentrations used were correspondent to the environmentally relevant levels. The biomarkers of stress and toxicity were evaluated in digestive gland, except the lysosomal membrane stability measured in hemocytes. All exposures caused an oxidative stress due to the decreased SOD and GST activities and decreased GSH/GSSG ratio, increased levels of thiobarbituric acid-reactive substances and protein carbonyls (with exceptions of Dc and MixT treatments). Diclofenac increased lysosomal cathepsin D activity. Nifedipine increased lysosomal membrane stability and caspase-3 activity. Roundup caused a dramatic distortion of metallo-thiolome due to highly increased levels of GSH and metallothionein-related thiols (MTSH) as well as depletion of Zn, Cu and Cd in the composition of metallothioneins, and decreased Zn/Cu molar ratio in the tissue. The particular toxicity of Rn was also attested by decreased lysosomal membrane stability and cholinesterase activity, and by the highest value of integrated biomarker index. Generally, compound-specific effects were expressed in U. tumidus responses to the mixture of pharmaceuticals and herbicide at both temperatures. Multi-marker approach and integrative analysis proved to be a useful tool for understanding possible future risks to freshwater mussels under a combination of xenobiotics and warming climate

Common and particular biochemical responses of Unio tumidus to herbicide, pharmaceuticals and their combined exposure with heating

The priority list of freshwater pollutants is increasingly amended by pharmaceuticals. Their impact on the aquatic biota can be modulated by the presence of typical pollutants, like pesticides, and/or abnormal heating. The aim of this study was to elucidate potentially hazardous impact of combined environmental factors on the freshwater mussels by analysing various sets of biochemical markers. We treated the bivalve molluscs of Unio tumidus with non-steroidal anti-inflammatory drug diclofenac (Dc, 2 nM), calcium antagonist and antihypertensive drug nifedipine (Nf, 2 nM) or organophosphonate glyphosate-based herbicide Roundup MAX (Rn, 79 nM of glyphosate) at 18oC as well as with the mixture of these substances at 18oC (Mix) or 25oC (MixT) during 14 days. The concentrations used were correspondent to the environmentally relevant levels. The biomarkers of stress and toxicity were evaluated in digestive gland, except the lysosomal membrane stability measured in hemocytes. All exposures caused an oxidative stress due to the decreased SOD and GST activities and decreased GSH/GSSG ratio, increased levels of thiobarbituric acid-reactive substances and protein carbonyls (with exceptions of Dc and MixT treatments). Diclofenac increased lysosomal cathepsin D activity. Nifedipine increased lysosomal membrane stability and caspase-3 activity. Roundup caused a dramatic distortion of metallo-thiolome due to highly increased levels of GSH and metallothionein-related thiols (MTSH) as well as depletion of Zn, Cu and Cd in the composition of metallothioneins, and decreased Zn/Cu molar ratio in the tissue. The particular toxicity of Rn was also attested by decreased lysosomal membrane stability and cholinesterase activity, and by the highest value of integrated biomarker index. Generally, compound-specific effects were expressed in U. tumidus responses to the mixture of pharmaceuticals and herbicide at both temperatures. Multi-marker approach and integrative analysis proved to be a useful tool for understanding possible future risks to freshwater mussels under a combination of xenobiotics and warming climate

Common and particular biochemical responses of Unio tumidus to herbicide, pharmaceuticals and their combined exposure with heating

The priority list of freshwater pollutants is increasingly amended by pharmaceuticals. Their impact on the aquatic biota can be modulated by the presence of typical pollutants, like pesticides, and/or abnormal heating. The aim of this study was to elucidate potentially hazardous impact of combined environmental factors on the freshwater mussels by analysing various sets of biochemical markers. We treated the bivalve molluscs of Unio tumidus with non-steroidal anti-inflammatory drug diclofenac (Dc, 2 nM), calcium antagonist and antihypertensive drug nifedipine (Nf, 2 nM) or organophosphonate glyphosate-based herbicide Roundup MAX (Rn, 79 nM of glyphosate) at 18oC as well as with the mixture of these substances at 18oC (Mix) or 25oC (MixT) during 14 days. The concentrations used were correspondent to the environmentally relevant levels. The biomarkers of stress and toxicity were evaluated in digestive gland, except the lysosomal membrane stability measured in hemocytes. All exposures caused an oxidative stress due to the decreased SOD and GST activities and decreased GSH/GSSG ratio, increased levels of thiobarbituric acid-reactive substances and protein carbonyls (with exceptions of Dc and MixT treatments). Diclofenac increased lysosomal cathepsin D activity. Nifedipine increased lysosomal membrane stability and caspase-3 activity. Roundup caused a dramatic distortion of metallo-thiolome due to highly increased levels of GSH and metallothionein-related thiols (MTSH) as well as depletion of Zn, Cu and Cd in the composition of metallothioneins, and decreased Zn/Cu molar ratio in the tissue. The particular toxicity of Rn was also attested by decreased lysosomal membrane stability and cholinesterase activity, and by the highest value of integrated biomarker index. Generally, compound-specific effects were expressed in U. tumidus responses to the mixture of pharmaceuticals and herbicide at both temperatures. Multi-marker approach and integrative analysis proved to be a useful tool for understanding possible future risks to freshwater mussels under a combination of xenobiotics and warming climate

Biochemical marker analysis of Unio tumidus response to Roundup, chlorpromazine and elevated temperature applied separately and jointly

Bivalve molluscs represent the most recognised bioindicators of freshwater pollution. However, their ability to indicate specific xenobiotics in complex exposures is unclear. This study aimed to explore the effects of common pollutants, pesticide Roundup (Rn) and antipsychotic drug chlorpromazine (Cpz) on the mussels Unio tumidus at environmentally relevant concentrations. The mussels were treated separately to Rn (17 µg L−1) and Cpz (18 µg L−1) and jointly to Rn and Cpz at 18 oC (RnCpz) as well as to Rn at 25 oC (RnT). Digestive glands were examined after 14 days of exposure. Shared responses were the increase of the level of Zn-metallothioneins and antioxidant activity (ABTS test) in all groups, the increases of the GSH/GSSG ratio, protein carbonyls, CYP450 related activity (EROD) (by three times in RnT- and Cpz-groups), and citrate synthase activity in the RnT-, RnCpz- and Cpz-groups, and increase of metallothionein protein concentration in all groups except Cpz. Cholinesterase and caspase-3 activities increased in Rn- and RnCpz- groups and GST in Rn-group. Cpz caused a decrease in GST activity and Zn level in the tissue and an increase in lysosomal integrity. The highest injury was indicated in the RnT-group due to the decrease of lysosomal integrity. According to discriminant analysis, Rn- and control groups were less different, Cpz caused major response diverseness, and complex exposures abolished the individual response traits. Summarising, multi-marker expertise with the application of integrated indices has benefits when evaluating the effects of complex exposures

Multi-marker study of the responses of the Unio tumidus from the areas of small and micro hydropower plants at the Dniester River basin, Ukraine

The aim of this study was to evaluate the environmental impact of the hydropower plants (HPPs) utilizing the bivalve mollusk Unio tumidus. The upstream and downstream of the dam sites of small HPPs and micro HPPs were examined. The indices of stress and toxicity were determined in the digestive gland, hemocytes (lysosomal integrity) and honads (alkali-labile phosphates, ALP). The mollusks from the reservoirs of small HPPs show the depletion of the cholinesterase, the highest glutathione S-transferase, ALP (by ~5 times) and metallothionein levels, low concentration of glutathione, the highest extralysosomal activity of the cathepsin D (CTD), the loss of the lysosomal integrity and a high copper concentration, indicating pollution from agricultural and municipal wastes. The specimens from the micro HPP area had the highest level of glutathione and lipid peroxidation and a low Cu,Zn-SOD activity and low morphological indexes

Multi-marker study of the responses of the Unio tumidus from the areas of small and micro hydropower plants at the Dniester River basin, Ukraine

The aim of this study was to evaluate the environmental impact of the hydropower plants (HPPs) utilizing the bivalve mollusk Unio tumidus. The upstream and downstream of the dam sites of small HPPs and micro HPPs were examined. The indices of stress and toxicity were determined in the digestive gland, hemocytes (lysosomal integrity) and honads (alkali-labile phosphates, ALP). The mollusks from the reservoirs of small HPPs show the depletion of the cholinesterase, the highest glutathione S-transferase, ALP (by ~5 times) and metallothionein levels, low concentration of glutathione, the highest extralysosomal activity of the cathepsin D (CTD), the loss of the lysosomal integrity and a high copper concentration, indicating pollution from agricultural and municipal wastes. The specimens from the micro HPP area had the highest level of glutathione and lipid peroxidation and a low Cu,Zn-SOD activity and low morphological indexes

Biochemical responses of freshwater mussel Unio tumidus to titanium oxide nanoparticles, Bisphenol A, and their combination

The aim of the study was to evaluate the combined effect of two widespread xenobiotics, titanium oxide nanoparticles (TiO2) and bisphenol A (BPA), on freshwater bivalve Unio tumidus. The specimens were exposed for 14 days to TiCl4 (Ti, 1.25 µM), TiO2 (1.25 μM), BPA (0.88 nM), or their combination (TiO2+BPA). Every type of exposure resulted in a particular oxidative stress response: TiO2 had antioxidant effect, decreasing the generation of reactive oxygen species (ROS) and phenoloxidase (PhO) activity, and doubling reduced glutathione (GSH) concentration in the digestive gland; Ti caused oxidative changes by increasing levels of ROS, PhO and superoxide dismutase; BPA decreased the GSH level by a factor of two. In the co-exposure treatment, these indices as well as lysosomal membrane stability were not affected