Xenobiotic Biotransformation System Research Articles

Genetic association of the xenobiotic biotransformation system with the risk of death of the gestational sac in primigravida women living in an industrial city

Introduction. Every second conception in the population ends in failure, in 20% of the cases the cause is a non-developing pregnancy. In the overall structure of early reproductive losses, missed miscarriage accounts for 80%. The development of this pathology is influenced by both endogenous and exogenous factors. Exogenous factors with a teratogenic effect lead to the occurrence of mutations and the formation of an abnormal embryo, which is poorly predicted. The peculiarities of the biotransformation system of xenobiotics of the maternal organism directly affect the severity of the impact of these factors on the embryo. Materials and methods. A survey of eighty six young primigravida women living in Novokuznetsk was conducted. 33 of them were diagnosed with the gestational sac death, 53 women had a standard developed pregnancy. Variants of the GSTM1 and GSTT1 genes of the second phase of the xenobiotic biotransformation system were determined in these groups by polymerase chain reaction. Results. Novokuznetsk, a city with a critically high level of environmental pollution, has recorded a 20–fold increase in the number of missed miscarriages over the past 25 years. A statistically reliable association of deletion polymorphisms of the genes of the second phase of the xenobiotic biotransformation system with the death of the gestational sac - GSTM1 (χ2 – 5.37; OR – 3.18) and GSTT1 (χ2 – 10.85; OR – 16.64) was revealed, while the normal alleles were associated with a successful outcome of pregnancy - GSTM1 (χ2 – 5.37; OR – 0.13) and GSTT1 (χ2 – 10.85; OR – 0.06). Limitations. The study was of a pilot nature, so it is advisable to increase the sample in the future. Conclusion. The dependence between the activity of enzymes of the second phase of the xenobiotic biotransformation system and the increased risk of miscarriage of the first pregnancy in young women living in the conditions of ecological distress was revealed. The results of the study make it possible to predict possible pregnancy complications and elaborate algorithms for full-fledged pregravid preparation.

Polymorphism of xenobiotic biotransformation enzyme genes and their role in early pregnancy loss

Considering the progressive decrease in the number of women of fertile age, as well as children and adolescents, the primary medical and social task at the present stage is to preserve the reproductive health and life of women, preserving every desired pregnancy. The concept of demographic policy of the Russian Federation for the period until 2025 defines the global national goals, i.e. to increase the total fertility rate by 1.5 times, to reduce maternal and infant mortality by at least 2 times, and to improve the reproductive health of women, children and adolescents. Today every fifth desirable pregnancy ends in early loss, and the rate of miscarriage does not tend to decrease and, in fact, increases every year. Carriage of susceptibility or candidate genes can alter the course of biochemical processes in women and cause early pregnancy losses. According to the literature, the cytochrome P-450 gene (CYP1A1, CYP1B1), xenobiotic detoxification genes (GSTT1, GSTM1, GSTP1) and many others are recognized as candidate genes (genetic markers) associated with reproductive losses. Adverse pregnancy outcome is usually multifactorial; in turn, the combination of polymorphic variants of different candidate genes can increase the risk of early losses. A detailed study of the role of candidate genes with clarity and confirmation of the interest of candidate genes in the development of pregnancy loss is undeniable. In this regard, the interest of many researchers in studying the polymorphism of genes of the xenobiotic biotransformation enzyme system as one of the causal factors of pregnancy failure is understandable. The study of this group of genes is of particular relevance in regions with developed industry and high anthropogenic load. The article is devoted to the analysis of the existing data of foreign and domestic literature sources concerning the relationship between polymorphism of xenobiotic biotransformation system genes and reproductive losses.

Oxidative stress in animals exposed to cypermethrin: mechanisms of development and possible risks

The purpose of the study is to establish the mechanisms of development of oxidative stress during long-term low-dose exposure to cypermethrin on the animal organism and to substantiate possible risks. The work was carried out using Wistar rats, which were intragastrically injected daily with cypermethrin at a dose of 1/1000 LD50 for 60 and 120 days. At the same time, control animals received an appropriate volume of saline solution inside. When removing animals from the experiment, blood was taken to determine the number of red blood cells, the concentration of hemoglobin, glucose, lactic and uric acids, and total bilirubin. In the study of erythrocytes and liver, biochemical parameters characterizing carbohydrate and purine metabolism, processes of xenobiotics biotransformation, pro- and antioxidant processes were determined. Long-term lowdose exposure to cypermethrin for 60 days causes hematotoxic effects in animals, enhancement of xenobiotic biotransformation processes, and slight compensatory restructuring of metabolic processes in the liver. Exposure to 1/1000 LD50 of cypermethrin for 120 days, in addition to the above effects, causes the development of acidosis, enhances pro-oxidant processes, and suppresses the function of the antioxidant defense system and the pentose cycle. The decrease in the activity of the liver antioxidant system is due to glutathione deficiency due to the activation of xenobiotic biotransformation systems and suppression of the activity of glutathione reductase and glucose-6- phosphate dehydrogenase, which ultimately leads to the development of oxidative stress. Long-term exposure of animals to low doses of cypermethrin causes hemolysis of erythrocytes, lactic acidosis, activation of prooxidant systems, and inhibition of the antioxidant defense system. Deficiency of carbohydrates and suppression of the activity of the pentose cycle indicate a decrease in the functional activity of the liver and an increased risk of immunosuppression.

Association of CYP1A2 gene polymorphism (rs762551) with the risk 
 of breast cancer and miscarriage of the first pregnancy

Introduction. Missed pregnancy, as a rule, is caused by a combination of several factors. Exogenous factors can have a teratogenic effect, leading to the occurrence of mutations of varying severity. In such case at the early stages of embryogenesis, serious disturbances occur, leading to a halt in the pregnancy development. The system of their biotransformation is responsible for the elimination of xenobiotics from the body, the inadequate functioning of which increases the activity of mutagenesis, which may raise the risk of breast cancer.
 Materials and methods. One hundred thirty four women were examined. The first group included 63 women, 28 of them were diagnosed with fetal egg death in primigravida young women, in 35 women the first pregnancy ended with physiological childbirth. The second group included 71 woman, 33 of them were diagnosed with a malignant breast neoplasm, 38 had no suspicion of breast cancer (BC) according to the results of mammography. Polymorphisms of the CYP1A2*1F gene of the xenobiotic biotransformation system in these groups were determined by polymerase chain reaction.
 Results. In the group of women with a missed first pregnancy, a statistically reliable association of a high risk of the fetal egg death with the A/A CYP1A2*1F genotype and resistance to this pathology in the case of the C/A CYP1A2*1F polymorphism was revealed. In the group of BC women, the association of a high risk of developing a malignant neoplasm with the A/A CYP1A2*1F genotype and resistance to the development of the disease in the presence of C/A CYP1A2*1F polymorphism was shown.
 Limitations. The study was limited by the number of samples, there is no data on polymorphisms of the BRCA-1, BRCA-2 genes.
 Conclusion. The results obtained will allow not only adjusting the tactics of pregnancy management in women with a high risk of the fetal egg death or the selection of pharmacological drugs in the treatment of BC under the conditions of serious environmental stress, but also developing preventive measures to reduce the risk of these pathologies.

Trigger Mechanisms of Cypermethrin-Induced Changes of Metabolism: An Experimental Study

Background: The purpose of this work was to study the triggering mechanisms of metabolic changes in experimental animals after a single injection of cypermethrin at a dose of 55 mg/kg of body weight. Methods and Results: Sixty rats were randomly divided into four groups (15 rats in each group). Rats of the control groups (G1 and G3) were injected with saline into the stomach. Animals of the experimental groups (G2 and G4) were injected once with the synthetic pyrethroid cypermethrin at a dose of 55 mg/kg of body weight, which is 1/5 LD50. Before being withdrawn from the experiment, blood was taken in vivo under anesthesia, and the liver was removed. The glucose, lactate, uric acid, and total bilirubin concentrations were determined in blood serum by unified research methods. The content of glutathione (GSH), malondialdehyde (MDA), and activity of glucose-6-phosphate dehydrogenase (G6PDH) was determined in erythrocyte hemolysates. In liver homogenates, the content of total protein, glycogen, uric acid, and inorganic phosphorus (Pi) was determined by unified methods, as well as MDA, GSH, activity of G6PDH, microsomal oxygenase, glutathione-S-transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR). Administration of cypermethrin to laboratory rats at a dose of 1/5 LD50 causes adaptive changes in metabolism. After one day, there was an increase in the content of glucose in the blood serum against the background of a deficiency of carbohydrates in the liver tissue. At the same time, there was an increase in anaerobic oxidation and an increase in purine catabolism, which was associated with the activation of lipid peroxidation (LP) of cell membranes and the depletion of the pool of antioxidants. GSH deficiency was exacerbated by an increase in the activity of antioxidant enzymes and xenobiotic biotransformation systems. Seven days after the administration of cypermethrin, rats retained a high rate of breakdown of purines to uric acid. This process was enhanced by a decrease in the RBC, a deficiency of carbohydrates, and inhibition of the activity of G6PDH, GPx, and GR. This ultimately led to the development of oxidative stress. Conclusion: The triggers for the development of oxidative stress under cypermethrin exposure are lactic acidosis and increased catabolism of purine mononucleotides, accompanied by an increase in the production of free radicals and inhibition of the function of the antioxidant system. A decrease in the blood RBC, carbohydrate deficiency, and suppression of the activity of the pentose cycle 7 days after the administration of cypermethrin aggravate this condition.

A study of the effect of gene polymorphism of xenobiotic biotransformation system, matrix metalloproteinases and interleukins on the development and course of distal neuropathy and diabetic foot syndrome in patients with type 1 and type 2 diabetes mellitus

Aim to improve the effectiveness of early diagnosis, prediction and therapy of distal neuropathy (DN) and diabetic foot syndrome (DFS) in patients with type 1 and type 2 diabetes by identifying the features of gene polymorphism of xenobiotic biotransformation systems and antioxidant protection, pro- and anti-inflammatory cytokines.
 Material and methods. The study group included 150 patients aged from18 to 70 years, men and women with type 1 and type 2 diabetes, having DN and DFS, and 20 healthy people. Research methods used in the study: 1) clinical objective research; 2) molecular genetic methods; 3) population-statistics methods.
 Results. In patients with type 1 and type 2 diabetes with DN and DFS, the significant differences were found between the frequency of occurrence of polymorphism variants: G681A(*2) the CYP2C19 gene (2 = 9.642, p = 0.008), (OR = 0.334, (95% CI 0.145-0.768)); A8202G of the MMP9 gene (2 = 7.589, p = 0.022), (OR =0.476, (95% CI 0.226-1.005)); IIe105Val of the GSTP gene (2 = 19.521, p = 0.000), (OR = 0.174, (95% CI 0.070-0.435)); G-1293C(c1/c2) of the CYP2E gene (2 = 15.996, p = 0.000), (OR = 0.163, (95% CI 0.034-0.772)).
 Conclusion. Among patients suffering from type 1 and type 2 diabetes with the genotype A/A polymorphism G681A(*2) of the CYP2C19 gene, the DN and SDS are 4 times more likely to develop. The G/G polymorphism genotype A8202G of the MMP9 gene increases the risk of developing DN and DFS by almost 2 times. The genotype G/G polymorphism IIe105Val of the GSTP gene in patients increases the risk of developing DN and DFS by 4 times. The variant of the genotype C/C polymorphism G-1293C(c1/c2) of the CYP2E gene increases the risk of DN and DFS by 5 times.

РОЛЬ ПОЛИМОРФИЗМОВ ГЕНОВ СИСТЕМЫ БИОТРАНСФОРМАЦИИ КСЕНОБИОТИКОВ И АНТИОКСИДАНТНОЙ ЗАЩИТЫ В РАЗВИТИИ ДИАБЕТИЧЕСКОЙ НЕФРОПАТИИ

Introduction.The main etiopathogenetic mechanisms of the development of multifactorial diseases are genetic predisposition and environmental factors. A special role in the prognosis of type 1 diabetes mellitus is played by diabetic nephropathy, which leads to chronic kidney disease in its outcome. In the conditions of modern technogenic civilization, it is believed that the most significant contribution to the formation of predisposition to socially significant human diseases can be made by genes of enzymes of protective and adaptive systems of the body – these are, first of all, genes of enzymes of antioxidant protection and biotransformation of xenobiotics. The aim of the study was to study the role of polymorphic variants of genes of the xenobiotic biotransformation system and antioxidant protection (G681A in the CYP2C19 gene; G1293C in the CYP2E1 gene) in the development of diabetic nephropathy in patients with type 1 diabetes mellitus. Material and methods. The study included patients with type 1 diabetes mellitus (50 people) and healthy individuals (20 people). Molecular-genetic, clinical-laboratory and biochemical research methods were used. The reliability of differences in the distribution of genotype frequencies between groups of patients and healthy individuals was assessed by the test2, by the method of conjugate tables (four-field table). Results and discussion. The activity of the processes of free radical oxidation and lipid peroxidation increases many times in type 1 diabetes mellitus, which is confirmed in our study by an increase in the content of malondialdehyde products against the background of an increase in the activity of enzymes of the antioxidant defense system. This is especially evident in individuals carrying heterozygous polymorphism of the CYP2C19 (G681A) and CYP2E1 (G1293C) genes, which is also combined with a more pronounced decrease in kidney function in these patients compared with carriers of other polymorphic variants of the studied genes. Conclusion. Heterozygous polymorphism of the CYP2C19 (G681A) and CYP2E1 (G1293C) genes in combination with increased activity of antioxidant defense enzymes and xenobiotic biotransformation enzymes leads to a more severe course of diabetic nephropathy in patients with type 1 diabetes mellitus.

Genetic factors of toxic effects development in pollution liquidators of the former factory with mercury electrolysis technology

Introduction. According to genetic factors, it is possible to determine the degree of manifestation of the toxic effects of mercury. The latter justifies the assessment of the genetic status of the exposed contingent in order to identify hypersensitive individuals in whom adverse health effects can be realized when exposed to relatively low levels of the toxicant. The study aims to research the distribution of genotypes of some polymorphic variants of genes of the xenobiotic biotransformation system, heat shock proteins and tumor necrosis factor in the contingent involved in liquidation measures, as well as to identify individuals with a high prognostic risk of toxic effects due to exposure to mercury. Materials and methods. We conducted genotyping of 231 people (men only): 193 employees of the Ministry of Emergency Situations (MES) of Russia in the Irkutsk Region and 38 employees of the Federal Environmental Operator (FEO) involved in the elimination of mercury pollution at the industrial site of the mercury electrolysis plant and adjacent facilities on the territory of a former chemical plant in Eastern Siberia. The researchers used real-time PCR and PCR-RFLP methods to study polymorphic variants of the genes CYP1A1 (rs1048943), GSTP1 (rs1695 and rs1138272), TNF-α (rs1800629) and HSPA1B (rs1061581). Results. For the polymorphism of the GSTP1 gene (rs1695), we have identified an increase in the frequency of AG genotypes (p=0.043) and a decrease in the frequency of GG genotypes (p=0.048) in employees of the MES compared to those from the FEO group. The researchers didn’t detect carriers of the TT genotype for the polymorphic locus GSTP1 (rs1138272) in both examined groups. There was the carriage of the rare GG-CYP1A1 homozygote only in one MES employee. We found that 33 MES employees and 3 examined from the FEO group who are carriers of the GG-HSPA1B (+1267A/G) genotype have a high predictive risk of developing toxic effects due to mercury exposure. The experts discussed the data obtained with the results of genotyping of former mercury electrolysis shop workers who were chronically exposed to metallic mercury vapor. The experts have reviewed the data obtained from the results of genotyping of former employees of the mercury electrolysis shop who were chronically exposed to metallic mercury vapor Limitations. The limitations, first of all, should include the number of examined individuals in the FEO group, as well as the lack of data on deletion polymorphisms of the GSTT1 and GSTM1 genes, potentially having a significant role in the toxicokinetics of mercury. Conclusion. The study has revealed 36 carriers of the GG genotype of the polymorphic locus +1267A/G of the HSPA1B gene associated with a high prognostic risk of toxic effects associated with exposure to mercury among the employees of the Ministry of Emergency Situations (MES) and the FEO involved in liquidation work. Taking into account the forthcoming volume and duration of work related to the demercurization of the territory of the former factory with mercury electrolysis technology and the surrounding area it is advisable to take into account the results obtained when monitoring the health status of the liquidators. Ethics. We have received voluntary informed consent, approved by the Committee on Biomedical Ethics (Protocol No. 6 of 10.03.2020), from each employee being examined.

Gene polymorphism of the xenobiotic biotransformation system and the intrauterine fetal growth retardation in female workers of industrial enterprises

Intrauterine growth retardation is recognized as one of the leading causes of incidence and mortality in infancy and early childhood in all the countries of the world. The causes and mechanisms of development of this process are decisive when choosing the tactics of nursing such children. Of particular importance is the understanding of the functioning of the mother-placenta-fetus system, in particular the mechanisms of suppression of the detoxification function of the placenta in connection with the polymorphisms of the genes of the I and II phases of the xenobiotic biotransformation system. The aim of the study was to determine the relationship between the polymorphism of the genes of the I and II phases of the xenobiotic biotransformation system with the intrauterine fetal growth retardation in women living in the South of the Kemerovo region and working under harmful labor conditions. A survey of 39 women of reproductive age living in the territory of Novokuznetsk was carried out, 20 of them worked at various enterprises of the city. The study group included 14 women who gave birth to children with intrauterine growth retardation of varying severity. The comparison group (control) consisted of 25 women. They did not have spontaneous miscarriages and they carried a child without the intrauterine growth retardation. The work investigated the frequency of occurrence of polymorphisms of genes of the xenobiotic biotransformation system - CYP1A2*1F, GSTM1 (they determine the activity of detoxification enzymes), as well as their combinations - in a group of working women and housewives who gave birth to children with intrauterine growth retardation. The forms of genes associated with the intrauterine fetal growth retardation, as well as genes associated with the resistance to this pathology, were identified. Combinations of gene forms of different phases of the xenobiotic biotransformation and their relationship with intrauterine fetal growth retardation were shown. There were no statistically reliable differences between various cohorts of women. A positive association of a high risk of the intrauterine fetal growth retardation in women with A/A CYP1A2*1F genotype and deletion polymorphism of the GSTM1 "-" gene has been shown. The heterozygous form of the C/A CYP1A2*1F gene polymorphism is statistically reliably associated with the resistance to this pathology, as well as the normally functioning GSTM1 "+" gene. Genotype A/A CYP1A2*1F in the combination with the deletion polymorphism of GSTM1 "-" gene is statistically reliably associated with intrauterine fetal growth retardation, and C/A CYP1A2*1F genotype in the combination with normally functioning GSTM1 "+" gene is associated with a low risk of the intrauterine fetal growth retardation. Comparative analysis of the relationship of the studied forms of genes of the xenobiotic biotransformation system with the intrauterine fetal growth retardation in the groups of female workers and housewives did not show statistically reliable differences.

The degree of anthropogenic load, gene polymorphism of the xenobiotic biotransformation system and congenital malformations as links in the same chain

Introduction. According to epidemiological observations, the level of congenital malformations in children is associated with the degree of chemical pollution of the environment and certain forms of genes of the I and II phases of the xenobiotic biotransformation system. The study aimed to determine and compare the index of anthropogenic load with the probability of occurrence of congenital malformations of the fetus in combination with gene polymorphisms of I and II phases of the xenobiotic biotransformation system in women living in different administrative territories in the South of Kuzbass. Material and methods. The level of air pollution in the cities of the South of the Kemerovo region (Kuzbass) was established. Prenatal screening of 1,426 pregnant women at the term of 15-18 weeks in the cities of the South of Kuzbass was carried out. The Real Time-PCR method was used to determine the gene polymorphism of the xenobiotic biotransformation system (CYP1A2, GSTM1) in 53 women of Novokuznetsk who gave birth to newborns with congenital malformations. Results. In the cities of the South of Kuzbass, with a critical and high degree of pollution of atmospheric air and waterways, many women are at risk of congenital malformations in offsprings. The A/A CYP1A2*1F genotype in combination with the deletion polymorphism of the GSTM1 gene in the mother is reliably associated with the occurrence of congenital malformations in offsprings (χ2 - 4.72; р - 0.030; OR - 5.56; CI - 1.05-29.32), and the C/ACYP1A2*1F genotype in combination with the normal functioning GSTM1 “+” gene is associated with resistance to the development of congenital malformations (χ2 - 12.53; p - <0.001; OR - 0.11; CI - 0.03-0.4 ). Conclusion. Against the background of an increasingly unfavourable ecological situation in Kuzbass and raising the number of newborns with congenital malformations, it is essential to include in the algorithm for early prenatal diagnosis the determination of the forms of genes of different phases of the xenobiotic metabolism system to elaborate an algorithm for reducing the xenobiotic load on the body of pregnant women during critical periods of fetal organogenesis.

Biomarker-based assessment of sublethal toxicity of organic UV filters (ensulizole and octocrylene) in a sentinel marine bivalve Mytilus edulis

The global occurrence of organic UV filters in the marine environment is of increasing ecotoxicological concern. Here we assessed the toxicity of UV filters ensulizole and octocrylene in the blue mussels Mytilus edulis exposed to 10 or 100 μg l−1 of octocrylene and ensulizole for two weeks. An integrated battery of biochemical and molecular biomarkers related to xenobiotics metabolism and cellular toxicity (including oxidative stress, DNA damage, apoptosis, autophagy and inflammation) was used to assess the toxicity of these UV filters in the mussels. Octocrylene (but not ensulizole) accumulated in the mussel tissues during the waterborne exposures. Both studied UV filters induced sublethal toxic effects in M. edulis at the investigated concentrations. These effects involved induction of oxidative stress, genotoxicity (indicated by upregulation of DNA damage sensing and repair markers), upregulation of apoptosis and inflammation, and dysregulation of the xenobiotic biotransformation system. Octocrylene induced cellular stress in a concentration-dependent manner, whereas ensulizole appeared to be more toxic at the lower (10 μg l−1) studied concentration than at 100 μg l−1. The different concentration-dependence of sublethal effects and distinct toxicological profiles of ensulizole and octocrylene show that the environmental toxicity is not directly related to lipophilicity and bioaccumulation potential of these UV filters and demonstrate the importance of using bioassays for toxicity assessment of emerging pollutants in coastal marine ecosystems.

Acute Exposure to Crude Oil Induces Epigenetic, Transcriptional and Metabolic Changes in Juvenile Sciaenops ocellatus.

In this study, we report molecular and metabolic responses of Sciaenops ocellatus during an acute oil exposure bioassay (100, 800 and 8000mg 1-1 of crude oil). The global DNA methylation and expression profiles of key genes of the xenobiotic biotransformation system (cytochrome P450 1A [cyp1a] and glutathione S-tranferase [gst]), oxidative stress system (glutathione peroxidase [gpx], catalase [cat], aldehyde dehydrogenase [aldh]) and reproductive system (vitellogenin [vtg]) were evaluated. At the metabolic level, we evaluated the concentration of four polycyclic aromatic hydrocarbon (PAH) metabolites -hydroxybenzo[a]pyrene, hydroxypyrene, hydroxynaphthalene and hydroxyphenanthrene- in fish bile. The results of this study revealed that fish exposed to crude oil exhibited hypomethylation of DNA, up-regulation of cyp1a and gst and down-regulation of gpx, cat, aldh and vtg and high concentrations of PAH metabolites with respect to the control.

Biochemical and histopathological responses in peripubertal male rats exposed to agrochemicals isolated or in combination: A multivariate data analysis study

The widespread use of agrochemicals results in the exposure of the general human population, including children, to several of these chemicals simultaneously. In the present preclinical study, it was investigated the hepatic damages caused by exposure to acephate, carbendazim and mancozeb when administered alone or in different combinations (binary and ternary). Juvenile male Wistar rats were exposed to agrochemicals from post-natal day 53, by gavage. The doses of agrochemicals applied here were determined from previous studies whose results showed no signs of systemic toxicity. All exposures provoked a significant increase in DNA damage (except for acephate alone) and activation of the xenobiotic biotransformation system (except for the ternary mixture). Interestingly, the ternary mixture did not exhibit an exacerbation in adverse effects caused by agrochemicals isolated or in binary combination, even though they are sharing genotoxicity damage induction as a common toxicity pathway. Conversely, some effects observed for isolated or binary combinations of agrochemicals were not observed for ternary combination, suggesting a chemical interaction that could imply antagonism character. Using a multivariate data analysis approach, exposure to isolated agrochemicals were related to a group of adverse effects characterized by hepatic lesion and the attempt of the tissue to mobilize defense cells and increase mitotic rates to minimize damages. Binary mixtures also share similarities in relation to the effects they exhibited, mainly a moderate to high increase in the GST activity and in histopathological alterations suggesting that binary combinations trigger an increased response of the mechanism of xenobiotics biotransformation. Together, obtained results bring important insights regarding adverse effects and possible interaction of the three agrochemicals whose residues are commonly detected in agro-food products.

The role of some xenobiotic biotransformation genes snp in the development of acute pancreatitis

Genetically determined features of the xenobiotic biotransformation system play an important role in the development of acute pancreatitis (AP) and its complications. The aim of this study was to assess the contribution of 3 SNPs (CYP1A1 -462 T>C rs1048943, CYP2E1 -1293 G>C rs3813867 and ABCB1 -3435 G>A rs1045642) to the development of AP and its complications. DNA samples were collected from 547 unrelated patients with AP (154 women and 393 men; mean age 48.9 ± 13.1 years) undergoing therapy at surgery departments of Kursk and 573 unrelated individuals without gastrointestinal diseases (161 women and 412 men; mean age 47.8 ± 12.1 years). The polymorphisms were genotyped by PCR using TaqMan probes for allele discrimination. Infected pancreatic necrosis (IPN) was observed in 97 patients; 101 patients developed a pseudocyst (PC); 111 patients had a peripancreatic necrosis (PN). AP was the most common in the carriers of the А allele in ABCB1 G>A (rs1045642) (p = 0.0008). The carriers of the G/G genotype rarely developed both AP (p = 5·10–4) and its complications: IPN (p = 0.03R), PN (p = 0.036R), PC (p = 0.04R). The carriers of the G/C–C/C CYP2E1 G>C (rs3813867) genotypes who had no long-term history of alcohol abuse rarely developed AP (p = 0.03). The carriers of the G/C CYP2E1 (rs3813867) genotype tended to develop pseudocysts (p = 0.05OD). AP was more frequently complicated by IPN (p = 0.009R), PN (p = 0.003R) and PC (p = 0.003D) in the carriers of the C/C CYP1A1 T>C (rs1048943) genotype. A milder course of AP was typical for the carriers of the G/G ABCB1 G>A (rs1045642) genotype; a more severe course was characteristic of the carriers of the C/C CYP1A1 T>C (rs1048943) genotype.

THE RELATIONSHIP BETWEEN THE FREQUENCY OF CONGENITAL MALFORMATIONS IN NEWBORNS OF WOMEN RESIDING IN AN INDUSTRIAL REGION WITH THE POLYMORPHISM OF THE GENES OF THE BIOTRANSFORMATION SYSTEM

Introduction. There is a number of polymorphic genes, the products of which take part in the biotransformation process and possess of the different activity. As a result of an imbalance in the processes of xenobiotic biotransformation, there is occurred an accumulation of toxic electrophilic compounds, the rise in a mutagenic activity, that can be very important in the formation of congenital malformations. Therefore, the study of the association of gene polymorphisms of the first and second phases of biotransformation with various congenital malformations is topical. The aim of the study. To investigate the role of the polymorphism of genes of the xenobiotic biotransformation system (CYP1A2*1F, GSTT1, GSTM1) encoding the enzymes I and II detoxification phases in women with the complicated obstetric history, residing in an industrial region. Material and methods. A survey of 53 women of reproductive age living in the territory of Novokuznetsk was carried out. The comparison group (the control) consisted of 27 women. These women did not have spontaneous miscarriages, and they carried the fetus to term without congenital malformations. The study group included 26 women who gave birth to babies with congenital malformations. Genomic DNA was isolated by the phenol-chloroform extraction method followed by the ethanol precipitation. The molecular and genetic analysis of the gene polymorphism of cytochrome 1A2 (CYP1A2), glutathione S-transferase τ-1 (GSTT1) and glutathione S-transferase μ-1 (GSTM1) was carried out using Real-Time mode. Results. A high risk of congenital fetal malformations in women with the A/A CYP1A2*1F genotype and resistance to these pathologies in the presence of a heterozygous form of the gene C/A CYP1A2*1F was revealed. The relationship between the high risk of stillbirth due to the placental insufficiency in women with deletion polymorphism of the gene GSTM1 “-”, while the normal functioning gene GSTM1 “+” was associated with the resistance to antenatal fetal death.

ОСОБЕННОСТИ ПРОЦЕССОВ ЛИПОПЕРОКСИДАЦИИ И АНТИОКСИДАНТНОЙ ЗАЩИТЫ У МУЖЧИН-МОНГОЛОИДОВ, НОСИТЕЛЕЙ НЕФУНКЦИОНАЛЬНЫХ ПОЛИМОРФИЗМОВ ГЕНОВ GSTT1 И GSTM1, С РАЗЛИЧНЫМ СТАТУСОМ ФЕРТИЛЬНОСТИ

Background. Genetic factors cause 30-50 % of cases of male infertility different forms. We have conducted the investigation of the lipid peroxidation and antioxidant protection system components, associated with the biotransformation genes polymorphisms, in men with infertility. Aims: to study parameters of lipid peroxidation and antioxidant defense system associated with polymorphisms of biotransformation genes in infertile Mongoloid men. Materials and methods. The main group included 143 men of reproductive age from Mongoloid population who came to the Public Health Institution "Republican Perinatal Center" in Ulan-Ude with the problem of one year and more infertility after the marriage. Fifty-three almost healthy males with proven fertility were included in the control group. Blood samples of all men were genotyped by glutathione S-transferase (GSTP1, GSTM1, GSTT1) gene family and activity of glutathione system enzymes was determined. Results. In the fertile Mongoloids with non-functional genotype GSTT1(0/0)/GSTM1(0/0) we have established an increase concentration of a-tocopherol in serum, activity of glutathione peroxidase and a decrease in glutathione-S-transferase, as well as a decrease in the concentration of a-tocopherol. In infertile Mongoloids with non-functional GSTT1(0/0)/ GSTM1 (0/0) genotypes, an increase in the tiobarbituric acid reactants, glutathione peroxidase and a decrease in the concentration of a-tocopherol was found in the ejaculate; we also detected a decrease in the concentration of a-tocopherol, the level of oxidized glutathione and glutathione-s-transferase activity. Conclusions. Genetically determined peculiarities of functioning of the xenobiotic biotransformation system make each individual unique with regard to their adaptive capacity - resistance or sensibility to the damaging exo- and endogenous factors.

235 Association of the first phase xenobiotic biotransformation system genes with the risk of undesirable side effects and efficacy of antibiotic therapy in Russian CF children

235 Association of the first phase xenobiotic biotransformation system genes with the risk of undesirable side effects and efficacy of antibiotic therapy in Russian CF children

Transcriptional changes in oysters Crassostrea brasiliana exposed to phenanthrene at different salinities

Euryhaline animals from estuaries, such as the oyster Crassostrea brasiliana, show physiological mechanisms of adaptation to tolerate salinity changes. These ecosystems receive constant input of xenobiotics from urban areas, including polycyclic aromatic hydrocarbons (PAHs), such as phenanthrene (PHE). In order to understand the influence of salinity on the molecular responses of C. brasiliana exposed to PHE, oysters were acclimatized to different salinities (35, 25 and 10) for 15days and then exposed to 100μgL−1 PHE for 24h and 96h. Control groups were kept at the same salinities without PHE. Oysters were sampled for chemical analysis and the gills were excised for mRNA quantification by qPCR. Transcript levels of different genes were measured, including some involved in oxidative stress pathways, phases I and II of the xenobiotic biotransformation systems, amino acid metabolism, fatty acid metabolism and aryl hydrocarbon receptor nuclear translocator putative gene. Higher transcript levels of Sulfotransferase-like gene (SULT-like) were observed in oysters exposed to PHE at salinity 10 compared to control (24h and 96h); cytochrome P450 isoforms (CYP2AU1, CYP2-like1) were more elevated in oysters exposed for 24h and CYP2-like2 after 96h of oysters exposed to PHE at salinity 10 compared to control. These results are probably associated to an enhanced Phase I biotransformation activity required for PHE detoxification under hyposmotic stress. Higher transcript levels of CAT-like, SOD-like, GSTm-like (96h) and GSTΩ-like (24h) in oysters kept at salinity 10 compared to organisms at salinities 25 and/or 35 are possibly related to enhaced ROS production. The transcription of these genes were not affected by PHE exposure. Amino acid metabolism-related genes (GAD-like (24h), GLYT-like, ARG-like (96h) and TAUT-like at 24h and 96h) also showed different transcription levels among organisms exposed to different salinities, suggesting their important role for oyster salinity adaptation, which is not affected by exposure to these levels of PHE.

Responses of hepatic biochemical markers in bream Abramis brama L. to dietary administered polychlorinated biphenyls

An experimental study of the effects of dietary administered polychlorinated biphenyls (PCBs) on bream (Abramis brama L.) is reported in the present article. Responses of xenobiotic biotransformation system (ethoxyresorufin-O-deethylase and glutathione-S-transferase activities), antioxidant system (superoxide dismutase and catalase activities), and lipid peroxidation system (levels of conjugated dienes and malonic dialdehyde) are investigated. A PCB dose of 2 mg/kg feed does not cause irreversible physiological transformations in bream after 14 days of administration. The defense systems appear to efficiently suppress the effects of the xenobiotic and maintain stable and low intensity of the destructive processes at the exposure conditions used.

Coordinated induction of GST and MRP2 by cAMP in Caco-2 cells: Role of protein kinase A signaling pathway and toxicological relevance

The cAMP pathway is a universal signaling pathway regulating many cellular processes including metabolic routes, growth and differentiation. However, its effects on xenobiotic biotransformation and transport systems are poorly characterized. The effect of cAMP on expression and activity of GST and MRP2 was evaluated in Caco-2 cells, a model of intestinal epithelium. Cells incubated with the cAMP permeable analog dibutyryl cyclic AMP (db-cAMP: 1,10,100μM) for 48h exhibited a dose–response increase in GST class α and MRP2 protein expression. Incubation with forskolin, an activator of adenylyl cyclase, confirmed the association between intracellular cAMP and upregulation of MRP2. Consistent with increased expression of GSTα and MRP2, db-cAMP enhanced their activities, as well as cytoprotection against the common substrate 1-chloro-2,4-dinitrobenzene. Pretreatment with protein kinase A (PKA) inhibitors totally abolished upregulation of MRP2 and GSTα induced by db-cAMP. In silico analysis together with experiments consisting of treatment with db-cAMP of Caco-2 cells transfected with a reporter construct containing CRE and AP-1 sites evidenced participation of these sites in MRP2 upregulation. Further studies involving the transcription factors CREB and AP-1 (c-JUN, c-FOS and ATF2) demonstrated increased levels of total c-JUN and phosphorylation of c-JUN and ATF2 by db-cAMP, which were suppressed by a PKA inhibitor. Co-immunoprecipitation and ChIP assay studies demonstrated that db-cAMP increased c-JUN/ATF2 interaction, with further recruitment to the region of the MRP2 promoter containing CRE and AP-1 sites. We conclude that cAMP induces GSTα and MRP2 expression and activity in Caco-2 cells via the PKA pathway, thus regulating detoxification of specific xenobiotics.