Mehmet Bertan Yılmaz

Evaluation of the effects of androgen receptor gene trinucleotide repeats and prostate-specific antigen gene polymorphisms on prostate cancer.

The number of trinucleotide repeats [CAG (coding for polyglutamine), GGC (coding for polyglycine)] in the first exon of the androgen receptor (AR) gene and prostate-specific antigen (PSA) gene androgen response element I A/G polymorphism are both related to prostate cancer prognosis. We investigated whether these genomic changes occur in the AR and PSA genes, which are usually found in individuals with prostate cancer, of Turkish patients and to find out their distribution in the population. We used PCR and PCR-RFLP assays for AR and PSA genes, respectively, to detect molecular changes in 44 prostate cancer patients. Our findings indicate that individuals with prostate cancer tend to have around 18 CAG trinucleotide repeats. We observed significant differences between 22 controls, 33 benign prostate hyperplasia (BPH) patients and 44 adenocarcinoma patients for long CAG repeats. However, we did not find any significant differences in GGC repeats between controls, BPH and adenocarcinoma patients (P = 0.408). We also did not observe significant differences in the PSA A/G polymorphism frequency between controls, BPH and adenocarcinoma patients (P = 0.483). In conclusion, CAG and GGC repeats in the AR and PSA gene polymorphisms may be associated with prostate cancer risk and BPH in the Turkish population.

Sex-related effects of imidacloprid modulated by piperonyl butoxide and menadione in rats. Part II: genotoxic and cytotoxic potential

Abstract Despite its intended use, imidacloprid causes genotoxic and cytotoxic effects in mammals, especially in the presence of metabolic activation systems. The aim of this study was to determine to which extent these effects are sex related and how its metabolism modulators piperonyl butoxide and menadione affect its toxicity. Male and female Sprague-Dawley rats were injected with the intraperitoneal LD50 dose of imidacloprid alone (170 mg/kg) or pretreated with piperonyl butoxide (100 mg/kg) and menadione (25 mg/kg) for 12 and 24 h. Structural chromosome aberrations, abnormal cells and mitotic index were determined microscopically in bone marrow cells. Male rats showed susceptibility to the genotoxic effects of imidacloprid. Piperonyl butoxide was effective in countering this effect only at 24 h, whereas menadione exacerbated imidacloprid-induced genotoxicity. Piperonyl butoxide and menadione pretreatments increased the percentage of structural chromosome aberrations and abnormal cells in females. Imidacloprid decreased the mitotic index, whereas pretreatment with piperonyl butoxide and menadione showed improvement in both sexes. We believe that CYP450-mediated metabolism of imidacloprid is under the hormonal control and therefore that its genotoxicity is sex related. Piperonyl butoxide pretreatment also showed sex-related modulation. The hormonal effects on imidacloprid biotransformation require further investigation.

Association of serum sex steroid levels and bone mineral density with CYP17 and CYP19 gene polymorphisms in postmenopausal women in Turkey.

Many clinical conditions, including osteoporosis, are associated with serum levels of sex steroids. Enzymes that regulate rate-limiting steps of steroidogenic pathways, such as CYP17 and CYP19, are also regarded as significant factors that may cause the development of these conditions. We investigated the association of two common polymorphisms, in the promoter region (T→C substitution) of CYP17 and exon 3 (G→A) of CYP19, with bone mineral density (BMD) in the lumbar spine and femoral neck and serum androgen/estradiol, in a case-control study of 172 postmenopausal women aged 62.3 ± 9.6 years (mean ± SD). The CYP17 TC genotype was significantly overrepresented in patients compared to controls, and TC genotype neck T-score and lumbar T-score values were significantly higher in patients compared to controls. CYP17 TC and TT genotype testosterone and DHEA-SO(4) levels were lower in patients compared to controls. All three genotypes of CYP19 had almost the same distribution among patients. The CYP19 AG genotype, however, was most frequent among controls. CYP19 lumbar BMD levels were close to each other among the different genotypes; however, AA and AG genotypes were significantly lower in patients. Testosterone and DHEA-SO(4) levels in the CYP19 GG genotype were higher compared to those of the other genotypes in patients but not in controls. CYP19 GA individuals had lower E(2) levels and lower BMD in controls and patients. Femoral neck BMD and lumbar T-score were also diminished with GA transition. In conclusion, CYP17 and CYP19 gene polymorphisms were found to be associated with osteoporosis in postmenopausal women in Turkey.

Assessment of chromosomal aberration in the bone marrow cells of Swiss Albino mice treated by 4-methylimidazole

Abstract 4-Methylimidazole (4-MEI) is formed during the production of certain caramel coloring agents used in many food and drink products. It may also be formed during the cooking, roasting, or other processing of some foods and beverages. So it was unintentionally consumed in worldwide. This study was aimed to investigate the genotoxic and cytotoxic effects of 4-MEI using chromosome aberration (CA) and mitotic index (MI) in Swiss Albino mice. In this research, CA and MI of the mouse bone marrow cells were analyzed after treating the animals with 4-MEI (100, 130 and 160 mg/kg) for 12 h and 24 h treatment times. All data were analyzed using statistical methods. 4-MEI significantly increased the percentage of CAs at all concentrations for 12 h and at highest concentration for 24 h treatment periods. 4-MEI at highest concentration for 12 h and at all concentrations for 24 h decreased the MI in comparison with control. Genotoxic and cytotoxic effects of 4-MEI at 24 h treatment periods were concentration dependent. Consequently, it can be said that 4-MEI have genotoxic and cytotoxic effect in mouse.

Delineating the antigenotoxic and anticytotoxic potentials of 4-methylimidazole against ethyl methanesulfonate toxicity in bone marrow cell of swiss albino mice.

4-Methylimidazole (4-MEI) is mostly used in beverages and coloring food, dark beers and common brands of cola drinks, which may contain more than 100 μg of this compound per 12-ounce serving. This study was aimed to investigate the antigenotoxic and anticytotoxic effects of 4-MEI (100, 130 and 160 mg/kg) against ethyl methanesulfonate (240 mg/kg) using chromosome aberrations (CAs) and Mitotic index (MI) tests in bone marrow cells of Swiss Albino Mice at 12 h and 24 h treatment periods. So, the t-test was used for the statistical analysis.In this research, 4-MEI at all concentrations for 12 h treatment period reduced chromosomal aberrations and at 130 and 160 mg/kg concentrations for 24 h treatment period increased chromosomal aberrations induced by EMS (240 mg/kg), but th ese reductions and increases were not significant. Also, intraperitoneal injection of 4-MEI at doses of 100, 130 and 160 mg/kg combined with EMS (240 mg/kg) showed that the mitotic index was decreased at 100 and 130 mg/kg for 12h and 130 mg/kg for 24 h treatment periods, when compared to positive sample (EMS), but did not show any statistically difference from the EMS treated group. It can be concluded that 4-MEI might not be antigenotoxic and protective effects in bone marrow cells of Swiss Albino Mice, because 4-MEI could not reduce the chromosomal aberrations induced by EMS.

Sex-, tissue-, and exposure duration-dependent effects of imidacloprid modulated by piperonyl butoxide and menadione in rats. Part I: oxidative and neurotoxic potentials

Abstract Earlier research has evidenced the oxidative and neurotoxic potential of imidacloprid, a neonicotinoid insecticide, in different animal species. The primary aim of this study was to determine how metabolic modulators piperonyl butoxide and menadione affect imidacloprid’s adverse action in the liver and kidney of Sprague-Dawley rats of both sexes. The animals were exposed to imidacloprid alone (170 mg kg-1) or in combination with piperonyl butoxide (100 mg kg-1) or menadione (25 mg kg-1) for 12 and 24 h. Their liver and kidney homogenates were analysed spectrophotometrically for glutathione peroxidase, glutathione S-transferase, catalase, total cholinesterase specific activities, total glutathione, total protein content, and lipid peroxidation levels. Imidacloprid displayed its prooxidative and neurotoxic effects predominantly in the kidney of male rats after 24 h of exposure. Our findings suggest that the observed differences in prooxidative and neurotoxic potential of imidacloprid could be related to differences in its metabolism between the sexes. Co-exposure (90-min pre-treatment) with piperonyl butoxide or menadione revealed tissue-specific effect of imidacloprid on total cholinesterase activity. Increased cholinesterase activity in the kidney could be an adaptive response to imidacloprid-induced oxidative stress. In the male rat liver, co-exposure with piperonyl butoxide or menadione exacerbated imidacloprid toxicity. In female rats, imidacloprid+menadione co-exposure caused prooxidative effects, while no such effects were observed with imidacloprid alone or menadione alone. In conclusion, sex-, tissue-, and duration-specific effects of imidacloprid are remarkable points in its toxicity Sažetak Rezultati ranijih istraživanja pokazali su oksidativni i neurotoksični potencijal imidakloprida, neonikotinoidnog insekticida, u različitih životinjskih vrsta. Primarni je cilj ovog istraživanja bio utvrditi kako modulatori metabolizma piperonil butoksid i menadion utječu na nepovoljne učinke imidakloprida na jetra i bubrege muških i ženskih štakora soja Sprague-Dawley. Životinje su 12 h odnosno 24 h bile izložene samo imidaklopridu (170 mg kg-1) ili njegovoj kombinaciji s piperonil butoksidom (100 mg kg-1) odnosno menadionom (25 mg kg-1). U homogenatima jetara i bubrega spektrofotometrijski su utvrđene razine glutation peroksidaze, glutation S-transferaze, katalaze, specifične aktivnosti ukupne kolinesteraze, ukupni glutation, ukupni proteini te razine lipidne peroksidacije. Imidakloprid se pokazao prooksidativnim i neurotoksičnim uglavnom u bubrezima muških štakora nakon 24-satne izloženosti. Naši rezultati upućuju na to da su razlike u prooksidativnom i neurotoksičnom djelovanju imidakloprida povezane sa spolnim razlikama. Predtretmanom piperonil butoksidom odnosno menadionom (90 min prije davanja imidakloprida) otkriveno je da imidakloprid djeluje na ukupnu aktivnost kolinesteraze specifično za pojedina tkiva. Povišena aktivnost kolinesteraza u bubrezima mogla bi odražavati prilagodbu na oksidativni stres uzrokovan imidaklopridom. Piperonil butoksid odnosno menadion u jetrima muških štakora samo su pogoršali toksičnost imidakloprida. U ženki je djelovanje imidakloprida s menadionom bilo prooksidativno; takvo se djelovanje nije vidjelo nakon primjene samo imidakloprida odnosno samo menadiona. Vjerujemo da je promjenjivo djelovanje imidakloprida s obzirom na spol, tkivo i trajanje izloženosti važno za daljnja istraživanja njegove toksičnosti

Genetic polymorphisms of estrogen receptor alpha and catechol-O-methyltransferase genes in Turkish patients with familial prostate carcinoma.

OBJECTIVES: Estrogen is one of the most crucial hormones participating in the proliferation and carcinogenesis of the prostate glands. Genetic polymorphisms in the estrogen metabolism pathway might be involved in the risk of prostate carcinoma development. We evaluated the association between genetic polymorphisms in estrogen receptor alpha (ESR1) and catechol-O-methyltransferase (COMT) genes and the risk of developing familial prostate carcinoma. MATERIALS AND METHODS: In this study, 34 cases with prostate carcinoma whose first-degree relatives had prostate carcinoma and 30 healthy age-matched male controls were enrolled. The genotypes of ESR1 and COMT genes were analyzed employing polymerase chain reaction-restriction fragment length polymorphism method. 34 cases with prostate carcinoma, whose first degree relatives had prostate carcinoma and 14 age-matched male controls were enrolled to analyze the genotype of these two genes. RESULTS: Among control patients, the ESR1 PvuII genotypes of C/C, C/T and T/T were observed in 37%, 26% and 37%, respectively, whereas the C/C, C/T and T/T genotypes were observed in 18%, 41% and 41% of case patients, respectively. Among controls, the ESR1 PvuII allele frequencies of C and T were equally observed, whereas the C and T allele frequencies were observed in 38% and 62% of patients, respectively. Among ESR1 PvuII genotypes there were not any significant difference in terms of genotype (P = 0.199) and allele (P = 0.181) frequencies. Among controls, the ESR1 XbaI genotypes of G/G, G/A and A/A were observed in 33%, 37% and 33%, respectively, whereas the G/G, G/A and A/A genotypes were observed in 12%, 47% and 41% of patients, respectively. Among controls, the ESR1 XbaI allele frequencies of A and G were observed equally, respectively, whereas the A and G frequencies were observed in 65% and 35% of patients, respectively. Among ESR1 Χ baI, there was not any significant difference in terms of genotype (P = 0.111) and allele (P = 0.093) frequencies. But the C/C genotype of the PvuII site and G/G genotype of the XbaI site in the ESR1 gene were associated significantly with the risk of developing prostate carcinoma. The G/G, G/A and A/A genotypes of the COMT gene were observed in 50%, 29% and 21% of control patients and in 53%, 21% and 26% of case patients, respectively. The A and G allele frequencies of the COMT gene were observed in 36.7%, 63.3% of control patients and in 36.8%, 63.2% of case patients, respectively. In COMT gene, there was not any significant difference in terms of genotype (P = 0.843) and allele (P = 0.991) frequencies. But the G/A genotype of the COMT gene had a weak tendency toward increased risk. CONCLUSION: Polymorphisms of ESR1 gene in the estrogen metabolism pathway were associated significantly with familial prostate carcinoma risk. Single nucleotide polymorphisms of low-penetrance genes are targets for understanding the genetic susceptibility of familial prostate carcinoma.

Relation of Serum ADMA, Apelin-13 and LOX-1 Levels with Inflammatory and Echocardiographic Parameters in Hemodialysis Patients

Cardiovascular diseases are the leading causes of mortality in patients with chronic kidney disease. Nitric oxide has a critical role in both endothelial dysfunction and the atherosclerosis process. We aimed to investigate the relationships between serum asymmetric dimethyl arginine (ADMA), LOX‐1, and Apelin‐13 levels, which are known to act over nitric oxide with endothelial dysfunction and cardiac morphology as well as with each other in hemodialysis patients. The study comprised a total of 120 patients (53 females and 67 males) receiving hemodialysis three times a week for at least 6 months and an age‐gender matched control group (55 females and 58 males). Serum ADMA, LOX‐1, and Apelin‐13 levels were measured using the ELISA technique. Echocardiography, 24‐h blood pressure monitoring by the Holter and carotid artery intima‐media thickness (CIMT) measurement was performed on all of the included subjects. The associations between serum ADMA, LOX‐1, and Apelin‐13 levels with CIMT, echocardiographic parameters [left ventricular mass (LVM) and left ventricular mass index (LVMI)], and inflammatory markers [high sensitive C‐reactive protein (hsCRP) and neutrophil lymphocyte ratio (NLR)] were evaluated by correlation analysis. Serum ADMA, Apelin‐13, and LOX‐1 levels were significantly higher in the hemodialysis group than the controls (P < 0.001, P < 0.001, and P < 0.001, respectively). CIMT, hsCRP, and NLR levels were also significantly higher in the hemodialysis group (P < 0.05, P < 0.001, P < 0.001, respectively). Significant correlations were observed among the serum ADMA, Apelin‐13, and LOX‐1 levels. Moreover, notably positive correlations were found between these three biochemical markers and LVM, LVMI, hsCRP, and CIMT. Serum ADMA, Apelin‐13, and LOX‐1 levels can be indicators not only for the inflammatory process but also for the pathogenesis of cardiovascular diseases in hemodialysis patients.

ATP sensitive K+ channel subunits (Kir6.1, Kir6.2) are the candidate mediators regulating ameliorating effects of pulsed magnetic field on aortic contractility in diabetic rats

Diabetes mellitus is a metabolic disease that causes increased morbidity and mortality in developed and developing countries. With recent advancements in technology, alternative treatment methods have begun to be investigated in the world. This study aims to evaluate the effect of pulsed magnetic field (PMF) on vascular complications and contractile activities of aortic rings along with Kir6.1 and Kir6.2 subunit expressions of ATP-sensitive potassium channels (KATP ) in aortas of controlled-diabetic and non-controlled diabetic rats. Controlled-diabetic and non-controlled diabetic adult male Wistar rats were exposed to PMF for a period of 6 weeks according to the PMF application protocol (1 h/day; intensity: 1.5 mT; consecutive frequency: 1, 10, 20, and 40 Hz). After PMF exposure, body weight and blood glucose levels were measured. Then, thoracic aorta tissue was extracted for relaxation-contraction and Kir6.1 and Kir6.2 expression experiments. Blood plasma glucose levels, body weight, and aortic ring contraction percentage decreased in controlled-diabetic rats but increased in non-controlled diabetic rats. PMF therapy repressed Kir6.1 mRNA expression in non-controlled diabetic rats but not in controlled diabetic rats. Conversely, Kir6.2 mRNA expressions were repressed both in controlled diabetic and non-controlled diabetic rats by PMF. Our findings suggest that the positive therapeutic effects of PMF may act through (KATP ) subunits and may frequently occur in insulin-free conditions. Bioelectromagnetics. 39:299-311, 2018.

Apoptotic gene expression profiles and DNA damage levels in rat liver treated with perfluorooctane sulfonate and protective role of curcumin

Perfluorinated compounds (PFCs) such as PFOS and PFOA, are xenobiotics that can be detected worldwide in the environment and humans. PFOS (C8F17SO3-) is a fluorinated organic compound has been used for decades in industrial and commercial products. We investigated the genotoxic and apoptotic impact of PFOS in rat liver using comet assay, micronucleus test and apoptotic gene expression methods for caspase 3, caspase 8 and the protective role of curcumin on the PFOS- induced damage under chronic exposure. In this study, rats were treated either with three different PFOS doses only (0.6, 1.25 and 2.5mg/kg) or one dose of curcumin (80mg/kg) or three different doses of PFOS combined with 80mg/kg dose of curcumin by gavage for 30days at 48h intervals. We evaluated the DNA damage via comet assay and micronucleus test. Doses of PFOS increased micronucleus frequency (p<0.05) and strongly induced DNA damage in liver in two different parameters; i: the damaged cell percentage and ii: genetic damage index. Curcumin prevented the formation of DNA damage induced by PFOS and curcumin substance applied with PFOS caused a decrease in the micronucleus frequency. PFOS increased apoptotic gene expression but curcumin decreased the expression levels of caspase 3 and 8.