RESUMEN
In the last years, a number of in vitro studies have been performed to assess the genotoxic activity of titanium dioxide (TiO2 ). To resolve the contradictory results, in this study, we investigated the genotoxic activity of commercial TiO2 nanoparticles (NPs) and microparticles of different forms (anatase, rutile and mix of both). We evaluated micronucleus formation in stimulated lymphocytes, as well as DNA strand breaks and 8-oxo-7,8-dihydro-2'-deoxyguanosine in peripheral blood mononuclear cells (PBMCs), a mixed population of lymphocytes and monocytes. Different responses to TiO2 exposure were obtained depending on the assay. Both TiO2 NPs and microparticles and all the crystalline forms elicited a significant increase in 8-oxo-7,8-dihydro-2'-deoxyguanosine and DNA strand breaks in the whole PBMC population, without a concurrent increase of micronuclei in proliferating lymphocytes. The distribution of DNA damage in PBMCs, detected by the comet assay, that measures DNA damage at level of single cells, indicated the presence of a more susceptible cell subpopulation. The measurement of side scatter signals by flow cytometry highlighted the preferential physical interaction of TiO2 particles with monocytes that also displayed higher reactive oxygen species generation, providing a mechanistic explanation for the different responses observed in genotoxicity assays with PBMCs and lymphocytes. This study confirmed the suitability of human PBMCs as multi-cell model to investigate NP-induced DNA damage, but suggested some caution in the use of stimulated lymphocytes for the assessment of NP clastogenicity.
Asunto(s)
Daño del ADN , Leucocitos Mononucleares/efectos de los fármacos , Mutágenos/toxicidad , Nanopartículas/toxicidad , Titanio/toxicidad , Células Cultivadas , Ensayo Cometa , Humanos , Leucocitos Mononucleares/ultraestructura , Masculino , Tamaño de la Partícula , Propiedades de SuperficieRESUMEN
BACKGROUND: Human semen quality is affected by lifestyle and environmental factors. OBJECTIVE: To evaluate the short-term effects of a diet and physical activity intervention on semen quality of healthy young men living in highly polluted areas of Italy. DESIGN, SETTING, AND PARTICIPANTS: A randomized controlled trial was conducted. Healthy young men were assigned to an intervention or a control group. INTERVENTION: A 4-mo Mediterranean diet and moderate physical activity program. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcomes were sperm concentration, motility and morphology, concentration of round cells, and semen total antioxidant capacity. Secondary outcomes were adherence to Mediterranean diet and physical activity. All outcomes were measured twice, at the enrollment (t0) and at the end of the intervention (t4). RESULTS AND LIMITATIONS: A total of 263 individuals attended all visits, and underwent examinations and laboratory analyses: 137 in the intervention group and 126 in the control group. The adherence to Mediterranean diet and physical activity level increased more in the intervention group than in the control group from t0 to t4. Sperm concentration, total and progressive motility, and proportion of normal morphology cells increased in the intervention group but decreased in the control group, with statistically significant differences between the two groups at t4. The total antioxidant capacity increased in the intervention group but decreased in the control group, from t0 to t4. CONCLUSIONS: Study results showed that an intervention based on Mediterranean diet and regular physical activity can determine an improvement of semen quality in healthy young men. PATIENT SUMMARY: Our study aimed to evaluate the effect of a lifestyle intervention on semen quality of healthy young men. We assigned the 263 enrolled individuals to an intervention or a control group. The intervention group followed a 4-mo Mediterranean diet and moderate physical activity program, at the end of which the participants showed an improvement of semen quality parameters.
Asunto(s)
Dieta Mediterránea , Análisis de Semen , Antioxidantes , Humanos , Estilo de Vida , Masculino , Recuento de EspermatozoidesRESUMEN
BACKGROUND AND AIMS: The impact of severe inflammation on semen quality, including sperm DNA integrity, in men with inflammatory bowel disease [IBD] is unknown, as are the potential effects of anti-tumour necrosis factor-alpha [TNF-alpha] therapy. We investigated the influence of severe active IBD and anti-TNF-alpha treatment on semen quality. METHODS: We prospectively included 20 patients admitted with severe active IBD. Further, 19 patients who initiated and 17 who stopped anti-TNF-alpha therapy were included. Semen samples were obtained during active disease, and on/off treatment. For paired comparisons, samples were collected not less than 3 months after achieving remission, after treatment initiation, or after treatment cessation. Sperm DNA Fragmentation Index [DFI], concentration, morphology, and motility were evaluated. Sex hormones and seminal plasma anti-TNF-alpha drug levels were measured. RESULTS: In patients with severe disease, progressive sperm motility was impaired and increased significantly [from 28.4% to 37.4%, p = 0.045] during remission. There was no difference in DFI [12.5% versus 12.0%, p = 0.55], concentration [55.0 mill/ml versus 70.0 mill/ml, p = 0.39], or normal morphology [4.7% versus 5.1%, p = 0.51] in these patients. During active disease, testosterone was decreased, and normalised after obtaining remission. Patients who started anti-TNF-alpha therapy had a statistically significant, but clinically irrelevant, reduction in DFI after treatment initiation [12.8% versus 10.0%, p = 0.02]. All other semen parameters were unaffected by therapy. Anti-TNF-alpha drugs were excreted in negligible amounts in semen. CONCLUSIONS: Severe active IBD reduces progressive sperm motility and testosterone levels, but sperm DNA integrity is unaffected by active disease. Anti-TNF-alpha therapy does not impair sperm quality.
Asunto(s)
Adalimumab/uso terapéutico , Antiinflamatorios/uso terapéutico , Fragmentación del ADN , Enfermedades Inflamatorias del Intestino/complicaciones , Infliximab/uso terapéutico , Análisis de Semen , Espermatozoides/metabolismo , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adalimumab/sangre , Adulto , Antiinflamatorios/sangre , Fragmentación del ADN/efectos de los fármacos , Humanos , Enfermedades Inflamatorias del Intestino/patología , Infliximab/sangre , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Motilidad Espermática/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Testosterona/sangre , Adulto JovenRESUMEN
BACKGROUND AND AIMS: Sperm DNA integrity, concentration, and motility are suspected to be altered by thiopurines (azathioprine [AZA] and 6-mercaptopurine [6-MP]). We investigated the impact of thiopurines on semen quality in men with inflammatory bowel disease [IBD], by a comprehensive panel of semen analyses. METHODS: Semen from 40 men with IBD, in remission on AZA/6-MP therapy, was prospectively collected and compared with samples from 40 healthy volunteers. Paired samples [off and on AZA/6-MP] were obtained from a subset of IBD patients, and blood and semen were collected to determine 6-MP transmission to the ejaculate. Sperm DNA fragmentation was evaluated via sperm chromatin structure assay [SCSA] and Comet analysis. Conventional World Health Organization [WHO] parameters, i.e. semen volume and sperm concentration, motility, and morphology, were assessed. Additionally, we measured thioguanine nucleotide [TGN] incorporation in sperm cell DNA. RESULTS: Sperm DNA fragmentation levels did not differ between men with IBD on AZA/6-MP and healthy volunteers when evaluated by SCSA [p = 0.23] and Comet analysis [p = 0.72]. IBD patients on AZA/6-MP had significantly lower total and progressive sperm motility than healthy volunteers [48.5% versus 64.5%, p = 0.0003; 27.4% versus 43.3%, p = 0.0004; respectively], with no differences in concentration, volume, or morphology. The same trend was observed in the 10 paired samples. TGN incorporation was not detectable in sperm DNA, but 6-MP was detected in seminal plasma and correlated to blood levels [rs = 0.79, p = 0.02]. CONCLUSIONS: Thiopurines do not increase sperm DNA fragmentation but may impair sperm motility in this IBD cohort. Our findings support existing epidemiological data that thiopurine therapy is safe during preconception and should not be abandoned.
Asunto(s)
Azatioprina/efectos adversos , Fragmentación del ADN/efectos de los fármacos , Inmunosupresores/efectos adversos , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Mercaptopurina/efectos adversos , Análisis de Semen , Adolescente , Adulto , Azatioprina/sangre , Azatioprina/uso terapéutico , Estudios de Casos y Controles , ADN/química , Humanos , Inmunosupresores/sangre , Inmunosupresores/uso terapéutico , Masculino , Mercaptopurina/sangre , Mercaptopurina/uso terapéutico , Nucleótidos/análisis , Estudios Prospectivos , Semen/química , Espermatozoides , Tioguanina/análisis , Adulto JovenRESUMEN
Persistent organic pollutants (POPs), such as PCBs (polychlorinated biphenyls) and DDT [1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane], are environmental contaminants with potential endocrine disrupting activity. DNA methylation levels in peripheral blood lymphocytes have been associated with serum concentrations of POPs in Greenland Inuit and Korean populations. Greenland Inuits are characterized by the highest worldwide POP levels. In this cross-sectional study we evaluated the relationship between serum POP concentrations and DNA methylation levels in sperm of non-occupationally exposed fertile men from Greenland, Warsaw (Poland), and Kharkiv (Ukraine). Serum levels of PCB-153 [1,2,4-trichloro-5-(2,4,5-trichlorophenyl)benzene], as a proxy of the total PCBs body burden, and of p,p'-DDE [1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene], the main metabolite of DDT were measured. Sperm DNA methylation level was assessed globally by flow cytometric (FCM) immunodetection of 5-methyl-cytosines and at specific repetitive DNA sequences (Alu, LINE-1, Satα) by PCR-pyrosequencing after bisulfite conversion. Multivariate linear regression analysis was applied to investigate correlations between serum POP concentrations and DNA methylation. No consistent associations between exposure to POPs and sperm DNA methylation at repetitive DNA sequences were detected. A statistically significant global decrease in methylation was associated with exposure to either POP by FCM analysis. This is the first study to investigate environmental exposure to POPs and DNA methylation levels considering sperm as the target cells. Although POP exposure appears to have a limited negative impact on sperm DNA methylation levels in adult males, the global hypomethylation detected by one of the methods applied suggests that further investigation is warranted.
Asunto(s)
Metilación de ADN/efectos de los fármacos , Exposición a Riesgos Ambientales/efectos adversos , Contaminantes Ambientales/toxicidad , Espermatozoides/efectos de los fármacos , Adulto , Elementos Alu , DDT/toxicidad , Diclorodifenil Dicloroetileno/sangre , Diclorodifenil Dicloroetileno/toxicidad , Exposición a Riesgos Ambientales/análisis , Contaminantes Ambientales/sangre , Epigénesis Genética/efectos de los fármacos , Groenlandia , Humanos , Elementos de Nucleótido Esparcido Largo , Masculino , Polonia , Bifenilos Policlorados/sangre , Bifenilos Policlorados/toxicidad , Espermatozoides/fisiología , UcraniaRESUMEN
Persistent organochlorine pollutants (POPs) such as polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (p,p'-DDE), the major metabolite of dichlorodiphenyltrichloroethane (DDT), are stable lipophilic compounds widely found in the environment and in the general population. They can enter the food chain, and their negative impact on male reproduction is currently under active scrutiny. To explore the hypothesis that environmental exposure to these compounds is associated with altered sperm chromatin structure integrity in human sperm, we conducted a study of 176 Swedish fishermen (with low and high consumption of fatty fish, a very important exposure source of POPs). We determined serum levels of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and p,p'-DDE, and we used the sperm chromatin structure assay (SCSA) to assess sperm DNA/chromatin integrity. When CB-153 serum levels (individual dose range, 39-1,460 ng/g lipid) were categorized into equally sized quintiles, we found an association with the DNA fragmentation index (%DFI). A significantly lower %DFI was found in the lowest CB-153 quintile (< 113 ng/g lipid) compared with the other quintiles; there was a similar tendency, although not statistically significant, between %DFI and p,p'-DDE. These results suggest that POP exposure may have a slight negative impact on human sperm chromatin integrity.
Asunto(s)
Daño del ADN , Diclorodifenil Dicloroetileno/toxicidad , Contaminantes Ambientales/toxicidad , Bifenilos Policlorados/toxicidad , Espermatozoides/efectos de los fármacos , Adulto , Anciano , Cromatina/efectos de los fármacos , Diclorodifenil Dicloroetileno/sangre , Monitoreo del Ambiente , Contaminantes Ambientales/sangre , Citometría de Flujo , Humanos , Lípidos/análisis , Masculino , Persona de Mediana Edad , Bifenilos Policlorados/sangre , SueciaRESUMEN
Flow cytometry (FCM) has been extensively used to study mammalian sperm in the areas of reproductive toxicology (to monitor effects from environmental, occupational and therapeutic exposures), veterinary science (to preselect the gender of offspring by sorting X- and Y-chromosome-bearing sperm) and clinical andrology (to assess individual fertility potential). Using FCM, a variety of sperm features can now be rapidly measured on a cell-by-cell basis such as sperm count, viability, acrosomal integrity, mitochondrial function and DNA integrity; the last one is involved in postfertilization failure and embryo toxicity. It is foreseen that only a multiplex approach, which includes FCM assays together with the new genomics/proteomics methods, could increase the predictive power of fertility status and help identify susceptible subpopulations of men at risk for infertility, spontaneous abortions and birth defects.
Asunto(s)
ADN/análisis , Citometría de Flujo/métodos , Semen/fisiología , Espermatozoides/fisiología , Animales , Apoptosis , Cromatina/ultraestructura , Colorantes Fluorescentes , Humanos , Hibridación Fluorescente in Situ , Etiquetado Corte-Fin in Situ , Masculino , Técnicas Reproductivas Asistidas , Espermatozoides/química , Espermatozoides/ultraestructuraRESUMEN
Lonidamine (LND) [1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid], a well-known antispermatogenic drug, was studied for the first time in pubertal mice to assess its possible effects on spermatogenesis. Male CD1 mice were orally treated on Postnatal Day (PND) 28 with a single dose of LND (100 mg/kg body weight) and sacrificed on PND30, PND42, PND74 and PND123. On PND30 (48 h after dosing), severe testicular effects were evidenced in the treated animals: (a) reduction of the testicular sperm head concentration (approximately 50% of the control value); (b) changes in the spermatogenic cell type distribution (mild decrease of the elongated spermatids and S-phase cells fractions); and (c) morphological alterations of the Sertoli cell cytoplasm and germ cell exfoliation. These changes were recovered in adulthood, on PND74 and PND123. However, no effect on sperm chromatin structure was detected on the epididymal sperm of mature mice by sperm chromatin structure assay, suggesting that LND did not interfere with the process of chromatin reorganization and DNA packaging.
Asunto(s)
Antiespermatogénicos/farmacología , Indazoles/farmacología , Maduración Sexual , Espermatogénesis/efectos de los fármacos , Animales , Cromatina/ultraestructura , ADN/análisis , Citometría de Flujo , Indazoles/toxicidad , Masculino , Ratones , Tamaño de los Órganos/efectos de los fármacos , Recuento de Espermatozoides , Cabeza del Espermatozoide , Espermatozoides/efectos de los fármacos , Espermatozoides/fisiología , Espermatozoides/ultraestructura , Testículo/ultraestructuraRESUMEN
Lonidamine (LND) [1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid] is a well-known antispermatogenic drug. The aim of this study was to identify its possible long-term sequelae on the reproductive system of mice as compared with rats, where most data have been obtained until now. Sexually mature CD1 male mice were administered a single dose of LND (200 mg/kg bw by gavage) and killed 24 and 48 h, 6 days and 2, 4 and 8 weeks after the treatment. Testes were collected, weighed and (1) fixed in Bouin's solution for histological analysis or (2) reduced to monocellular suspensions and ethanol fixed to undergo flow cytometry (FCM) DNA content analysis. No effect on body weight and/or food consumption was observed in the treated group in comparison with the control group. Testicular weight was significantly reduced 24 h after the treatment. Reduced seminiferous epithelium with a progressive lack of intercellular cohesion and marked depletion of spermatids, infiltration of granulocytes, desquamation into the tubular lumen and increased intertubular spaces were present by 24 h after the treatment and persisted to a marked degree at 48 h, 6 days and 2 and 4 weeks up to a marked degeneration of tubular structures with absence of spermatogenesis. The same effects, albeit with a moderate severity, were still present 8 weeks after the treatment. As also detected by FCM, primary spermatocytes appeared to be the main cellular target. Sertoli and Leydig cells were remarkably spared. The histological findings are consistent with those previously observed in rats and point out that testicular damage may persist for several weeks after a single-dose administration. Findings are discussed in comparison with testicular toxicity elicited by other xenobiotics.
Asunto(s)
Antiespermatogénicos/farmacología , Indazoles/farmacología , Testículo/efectos de los fármacos , Animales , ADN/análisis , Citometría de Flujo , Indazoles/administración & dosificación , Masculino , Ratones , Tamaño de los Órganos/efectos de los fármacos , Epitelio Seminífero/citología , Epitelio Seminífero/efectos de los fármacos , Túbulos Seminíferos/efectos de los fármacos , Recuento de Espermatozoides , Espermatogénesis/efectos de los fármacos , Testículo/citología , Factores de TiempoRESUMEN
Long-lasting effects on mouse spermatogenesis induced by prenatal exposure to the insecticide lindane have been investigated by conventional reproductive endpoints complemented by the flow cytometric (FCM) DNA content analysis of testis cells and by the Sperm Chromatin Structure Assay (SCSA). Two lindane dose levels, 15 and 25 mg/kg bw, and diethylstilboestrol (DES, 10 microg/kg bw) as positive control, were administered daily by gavage to pregnant CD1 mice on gestation days (GD) 9-16. Reproductive endpoints were evaluated on F1 male mice on postnatal day (PND) 60; additionally, animals treated with lindane 25 mg/kg per day and DES were examined on PND 100 to evaluate the possible reversibility of the effects. On PND 60, lindane and DES caused a reduction in the sperm head count and concentration, with recovery in older lindane 25 mg/kg per day animals (PND 100). By contrast, the DES group exhibited a greater reduction in the sperm head count on PND 100 than on PND 60. Changes in biochemical parameters in the testes, lactate dehydrogenase-C(4) (LDH-C(4)), and sorbitol dehydrogenase (SDH) activities, were also observed in adult treated F1 mice. Furthermore on PND 60, the FCM analysis revealed changes in the pattern of testicular germ cell distribution, especially in the haploid subcompartment, in the lindane 25 mg/kg per day group. A dose-dependent increase in chromatin abnormalities of the epididymal sperm was also shown by SCSA. These changes recovered on PND 100. Preliminary qualitative examination did not reveal any significant difference in the structure of testicular tissue; however, there were suggestions of a moderate increase in number and size of Leydig cells in both DES- and lindane-treated animals. The partial reversibility of these effects and the lack of structural modification of the testicular tissue as evidenced by histopathologic assessment suggest a functional impairment of sperm production and maturation, possibly associated with changes induced by lindane on factors affecting intratesticular steroidogenesis.
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Antagonistas de Andrógenos/toxicidad , Contaminantes Ambientales/toxicidad , Hexaclorociclohexano/toxicidad , Exposición Materna/efectos adversos , Efectos Tardíos de la Exposición Prenatal , Espermatogénesis/efectos de los fármacos , Administración Oral , Antagonistas de Andrógenos/administración & dosificación , Animales , Animales Recién Nacidos , Cromatina/química , ADN/análisis , Daño del ADN , Dietilestilbestrol/administración & dosificación , Dietilestilbestrol/toxicidad , Contaminantes Ambientales/administración & dosificación , Femenino , Citometría de Flujo , Hexaclorociclohexano/administración & dosificación , Infertilidad Masculina/inducido químicamente , Masculino , Ratones , Ratones Endogámicos , Embarazo , Espermatogénesis/fisiología , Espermatozoides/efectos de los fármacos , Espermatozoides/patología , Testículo/química , Testículo/efectos de los fármacos , Testículo/patología , Pruebas de ToxicidadRESUMEN
Superparamagnetic iron oxide nanoparticles are candidate contrast agents for magnetic resonance imaging and targeted drug delivery. Biodistribution and toxicity assessment are critical for the development of nanoparticle-based drugs, because of nanoparticle-enhanced biological reactivity. Here, we investigated the uptake, in vivo biodistribution, and in vitro and in vivo potential toxicity of manganese ferrite (MnFe2O4) nanoparticles, synthesized by an original high-yield, low-cost mechanochemical process. Cultures of murine Balb/3T3 fibroblasts were exposed for 24, 48, or 72 hours to increasing ferrofluid concentrations. Nanoparticle cellular uptake was assessed by flow-cytometry scatter-light measurements and microscopy imaging after Prussian blue staining; cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony-forming assays. After a single intravenous injection, in vivo nanoparticle biodistribution and clearance were evaluated in mice by Mn spectrophotometric determination and Prussian blue staining in the liver, kidneys, spleen, and brain at different posttreatment times up to 21 days. The same organs were analyzed for any possible histopathological change. The in vitro study demonstrated dose-dependent nanoparticle uptake and statistically significant cytotoxic effects from a concentration of 50 µg/mL for the MTT assay and 20 µg/mL for the colony-forming assay. Significant increases in Mn concentrations were detected in all analyzed organs, peaking at 6 hours after injection and then gradually declining. Clearance appeared complete at 7 days in the kidneys, spleen, and brain, whereas in the liver Mn levels remained statistically higher than in vehicle-treated mice up to 3 weeks postinjection. No evidence of irreversible histopathological damage to any of the tested organs was observed. A comparison of the lowest in vitro toxic concentration with the intravenously injected dose and the administered dose of other ferrofluid drugs currently in clinical practice suggests that there might be sufficient safety margins for further development of our formulation.
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Supervivencia Celular/efectos de los fármacos , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/toxicidad , Manganeso/química , Manganeso/toxicidad , Animales , Células 3T3 BALB , Coloides/síntesis química , Coloides/toxicidad , Medios de Contraste , Difusión , Relación Dosis-Respuesta a Droga , Composición de Medicamentos/métodos , Femenino , Dosificación Letal Mediana , Ensayo de Materiales , Ratones , Especificidad de Órganos , Soluciones , Estrés Mecánico , Tasa de Supervivencia , Distribución TisularRESUMEN
Perfluoroalkyl substances (PFASs) are widely used in a variety of industrial processes and products, and have been detected globally in humans and wildlife. PFASs are suspected to interfere with endocrine signaling and to adversely affect human reproductive health. The aim of the present study was to investigate the associations between exposure to PFASs and sperm global methylation levels in a population of non-occupationally exposed fertile men. Measurements of PFASs in serum from 262 partners of pregnant women from Greenland, Poland and Ukraine, were also carried out by liquid chromatography tandem mass spectrometry. Perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) were detected in 97% of the blood samples. Two surrogate markers were used to assess DNA global methylation levels in semen samples from the same men: (a) average DNA methylation level in repetitive DNA sequences (Alu, LINE-1, Satα) quantified by PCR-pyrosequencing after bisulfite conversion; (b) flow cytometric immunodetection of 5-methyl-cytosines. After multivariate linear regression analysis, no major consistent associations between PFASs exposure and sperm DNA global methylation endpoints could be detected. However, since weak but statistically significant associations of different PFASs with DNA hypo- and hyper-methylation were found in some of the studied populations, effects of PFASs on sperm epigenetic processes cannot be completely excluded, and this issue warrants further investigation.