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1.
Toxics ; 11(10)2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37888658

RESUMO

The continuous biomonitoring of a population directly or indirectly exposed to pesticides could be an additional tool for decision makers to improve their health conditions. In this work, we performed biomonitoring on two groups of people from the Mexicali Valley who were continuously exposed to pesticides using the cytokinesis-block micronucleus cytome assay (L-CBMN) to evaluate cytotoxic and genotoxic damage in human peripheral blood lymphocytes. The study groups comprised 14 indigenous Cucapah with non-vegetarian habits (NV group) from Ejido el Mayor (32.12594°, -115.27265°) and 21 lacto-ovo vegetarian (LOV) persons from the Seventh-day Adventist Church of Ejido Vicente Guerrero (32.3961°, -115.14023°). The L-CBMN assay determines the nuclear division index (NDI), apoptosis, necrosis, micronuclei (MNs), nuclear buds (NBUDs), and nucleoplasmic bridges (NPBs). Our results show that, regardless of diet or daily habits, both the studied groups presented with cytogenotoxic damage compared with non-exposed pesticide individuals, without modifications to the nuclear division index. In the rest of the evaluated biomarkers, the NV group exhibited greater cytotoxic and genotoxic damage than the LOV group. Nevertheless, individuals practicing a lacto-ovo vegetarian diet (LOV) showed lower damage than those with non-vegetarian habits (NV), suggesting a better antioxidant response that helps decrease the genotoxic damage due to the enhanced intake of folates and antioxidants from a plant-based diet.

2.
Artigo em Inglês | MEDLINE | ID: mdl-37003650

RESUMO

The micronucleus (MN) test may be used to evaluate genome instability in birds and the potential of different species to function as biomarkers of genotoxicity. However, little is known regarding genome instability in seabird embryos or the instability present among embryonic development stages. Therefore, the present study aimed to describe the frequencies of micronucleated erythrocytes (MNE) and micronucleated polychromatic erythrocytes (MNPCE) in blood samples collected from the embryos of eight seabird species nesting on the coast of Sinaloa, Mexico. An additional description of blood cell maturation along with embryo development during incubation was conducted based on the proportion of polychromatic erythrocytes (PCE), and the potential relationships between metals (Hg and Cd concentrations in egg content) and the MN frequencies in embryo blood were evaluated. The PCE proportion appears to decline as incubation advances (initial stage > intermediate stage > advanced stage), and the values varied between species (Suliformes/Pelecaniformes < Charadriiformes: Laridae), which may be related to differences among incubation periods and reproductive strategies. Interspecific variation in the MNPCE frequency was found in embryos showing advanced development, which could be related to both variations in life-history traits and ecological factors and not Hg or Cd exposure. The genomic instability values in this study are the first to be reported for embryos of seabird species nesting in a subtropical coastal region.


Assuntos
Cádmio , Micronúcleos com Defeito Cromossômico , Animais , Gravidez , Feminino , Micronúcleos com Defeito Cromossômico/induzido quimicamente , México , Testes para Micronúcleos , Eritrócitos , Aves , Instabilidade Genômica , Biomarcadores
3.
J Immunotoxicol ; 20(1): 2175078, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-36773297

RESUMO

Immunogenic cell death (ICD) is a form of cell death characterized by the release of danger signals required to trigger an adaptive immune response against tumor-associated antigens. Silver nanoparticles (AgNP) display anti-proliferative and cytotoxic effects in tumor cells, but it has not been previously studied whether AgNP act as an ICD inductor. The present study evaluated the in vitro release of calreticulin as a damage-associated molecular pattern (DAMP) associated with the cytotoxicity of AgNP and their in vivo anti-cancer effects. In vitro, mouse CT26 colon carcinoma and MCA205 fibrosarcoma cells were exposed to AgNP and then cell proliferation, adhesion, and release of calreticulin were determined. The results indicated there were time- and concentration-related anti-proliferative effects of AgNP in both the CT26 and MCA205 lines. Concurrently, changes in cell adhesion were detected mainly in the CT26 cells. Regarding DAMP detection, a significant increase in calreticulin was observed only in CT26 cells treated with doxorubicin and AgNP; however, no differences were found in the MCA205 cells. In vivo, the survival and growth of subcutaneous tumors were monitored after vaccination of mice with cell debris from tumor cells treated with AgNP or after intra-tumoral administration of AgNP to established tumors. Consequently, anti-tumoral prophylactic immunization with AgNP-dead cells failed to protect mice from tumor re-challenge; intra-tumor injection of AgNP did not induce a significant effect. In conclusion, there was a noticeable anti-tumoral effect of AgNP in vitro in both CT26 and MCA205 cell lines, accompanied by the release of calreticulin in CT26 cells. In vivo, immunization with cell debris derived from AgNP-treated tumor cells failed to induce a protective immune response in the cancer model mice. Clearly, further research is needed to determine if one could combine AgNP with other ICD inducers to improve the anti-tumor effect of these nanoparticles in vivo.


Assuntos
Antineoplásicos , Nanopartículas Metálicas , Camundongos , Animais , Calreticulina/metabolismo , Calreticulina/farmacologia , Prata , Morte Celular Imunogênica , Morte Celular , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral
4.
Animals (Basel) ; 11(11)2021 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-34827910

RESUMO

Micronuclei (MN) are used to assess genotoxic exposure, whereas nuclear buds (NBs) have been linked to genotoxic events. Crocodylus moreletii was studied to identify MN and NBs. Three groups were formed: Group 1 (water) and groups 2 and 3 (7 or 10 mg/kg of cyclophosphamide). A drop of blood was obtained daily from the claw tip at 0 to 120 h. Spontaneous micronucleated erythrocytes (MNEs) and erythrocytes with nuclear buds (NBEs) were counted. The frequencies of micronucleated young erythrocytes (MNYEs) and NB young erythrocytes (NBYEs) were evaluated, including the ratio of young erythrocytes (YE)/1000 total erythrocytes. No significant differences were observed in the YE proportion on sampling days; group 1 did not show differences for any parameter, whereas group 2 showed significant differences in MNEs and NBEs, and group 3 showed differences in NBEs and NBYEs. Some mitotic activity in circulation was observed in YEs. In conclusion, NBEs could be a more sensitive biomarker to genotoxic damage than MNEs. The identification of these biomarkers leads us to propose Crocodylus moreletii as a possible environment bioindicator because these parameters could be useful to analyze the in vivo health status of these reptiles and for biomonitoring genotoxic pollutants in their habitats.

5.
Nanomaterials (Basel) ; 11(8)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34443926

RESUMO

Silver nanoparticles (AgNPs) have been studied worldwide for their potential biomedical applications. Specifically, they are proposed as a novel alternative for cancer treatment. However, the determination of their cytotoxic and genotoxic effects continues to limit their application. The commercially available silver nanoparticle Argovit™ has shown antineoplastic, antiviral, antibacterial, and tissue regenerative properties, activities triggered by its capacity to promote the overproduction of reactive oxygen species (ROS). Therefore, in this work, we evaluated the genotoxic and cytotoxic potential of the Argovit™ formulation (average size: 35 nm) on BALB/c mice using the micronucleus in a peripheral blood erythrocytes model. Besides, we evaluated the capability of AgNPs to modulate the genotoxic effect induced by cyclophosphamide (CP) after the administration of the oncologic agent. To achieve this, 5-6-week-old male mice with a mean weight of 20.11 ± 2.38 g were treated with water as negative control (Group 1), an single intraperitoneal dose of CP (50 mg/kg of body weight, Group 2), a daily oral dose of AgNPs (6 mg/kg of weight, Group 3) for three consecutive days, or a combination of these treatment schemes: one day of CP doses (50 mg/kg of body weight) followed by three doses of AgNPs (one dose per day, Group 4) and three alternate doses of CP and AgNPs (six days of exposure, Group 5). Blood samples were taken just before the first administration (0 h) and every 24 h for seven days. Our results show that Argovit™ AgNPs induced no significant cytotoxic or acute genotoxic damage. The observed cumulative genotoxic damage in this model could be caused by the accumulation of AgNPs due to administered consecutive doses. Furthermore, the administration of AgNPs after 24 h of CP seems to have a protective effect on bone marrow and reduces by up to 50% the acute genotoxic damage induced by CP. However, this protection is not enough to counteract several doses of CP. To our knowledge, this is the first time that the exceptional chemoprotective capacity produced by a non-cytotoxic silver nanoparticle formulation against CP genotoxic damage has been reported. These findings raise the possibility of using AgNPs as an adjuvant agent with current treatments, reducing adverse effects.

6.
Front Vet Sci ; 7: 258, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32528983

RESUMO

Polydactyly, hypopigmentation, and squamous cell carcinoma are common in cats. However, a cat exhibiting all of these conditions has not yet been reported. This study presents the case of a 14- year-old male Mexican cat, hypopigmented, with supernumerary fingers, two preaxial and one on each posterior limb, admitted to the clinic with a lesion in the left periocular region. The cat was subjected to a general physical examination, blood, and urine chemistry, as well as a biopsy and genomic instability assessment with an analysis of the red blood cells (RBC) micronucleated erythrocytes (RBC-MNE) in the peripheral blood. The biopsy was positive for squamous cell carcinoma, and the RBC-MNE count (8.6 MNE/1000 erythrocytes) was high compared to that previously described in other domestic cats or wild cats. Thus, the genomic instability of the RBC-MNE could be used as an indicator to identify clinical conditions of felines, particularly those with one of the characteristics exhibited by this Mexican cat. The RBC-MNE test is the most widely used in the world for the evaluation of DNA damage, but to our knowledge, it has not been used to identify vulnerable non-human specimens.

7.
Nutrients ; 12(5)2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32384595

RESUMO

Nigella sativa (N. sativa) is a medicinal plant used for its therapeutic pharmacological effects such as anti-inflammatory, antioxidant, anticancer, antidiabetic, and immunomodulation. This study explored the anti-cytotoxic and anti-genotoxic effect of N. sativa through a micronucleus test (MNT) of BALB/c mice peripheral blood. Using 6-to-8-week-old healthy male BALB/c mice, four groups were formed: (1) Control (sterile water), single-dose 2 mg/kg/intraperitoneal (i.p); (2) N. sativa oil, 500 mg/kg/24 h/7 days/i.p; (3) Cisplatin (CP), single-dose 2 mg/kg/subcutaneous (s.c); (4) N. sativa + CP with their respective dosage. When evaluating polychromatic erythrocytes (PCE), a biomarker of cytotoxicity, the group treated with N. sativa + CP experienced an increase in the frequency of PCE, which demonstrated the recovery of bone marrow and modulation of cell proliferation. The analysis of micronucleated polychromatic erythrocytes (MNPCE), an acute genotoxicity biomarker, showed similar frequency of MNPCE within the groups except in CP, but, in the N. sativa + CP group, the frequency of MNPCE decreased and then regulated. Finally, the frequency of micronucleated erythrocytes (MNE), a biomarker of genotoxicity, the supplementation of N. sativa oil did not induce genotoxic damage in this model. Thus, we conclude that N. sativa has both cytoprotective, genoprotective effects and modulates cell proliferation in BALB/c mice.


Assuntos
Cisplatino/toxicidade , Citoproteção/efeitos dos fármacos , Eritroblastos/efeitos dos fármacos , Testes para Micronúcleos/métodos , Nigella sativa/química , Óleos de Plantas/farmacologia , Animais , Células da Medula Óssea/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cisplatino/administração & dosagem , Masculino , Camundongos Endogâmicos BALB C , Óleos de Plantas/administração & dosagem , Óleos de Plantas/isolamento & purificação
8.
Oxid Med Cell Longev ; 2019: 4528241, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428226

RESUMO

During the last 3 decades, there has been a slow advance to obtain new treatments for malignant melanoma that improve patient survival. In this work, we present a systematic study focused on the antiproliferative and antitumour effect of AgNPs. These nanoparticles are fully characterized, are coated with polyvinylpyrrolidone (PVP), and have an average size of 35 ± 15 nm and a metallic silver content of 1.2% wt. Main changes on cell viability, induction of apoptosis and necrosis, and ROS generation were found on B16-F10 cells after six hours of exposure to AgNPs (IC50 = 4.2 µg/mL) or Cisplatin (IC50 = 2.0 µg/mL). Despite the similar response for both AgNPs and Cisplatin on antiproliferative potency (cellular viability of 53.95 ± 1.88 and 53.62 ± 1.04) and ROS production (20.27 ± 1.09% and 19.50 ± 0.35%), significantly different cell death pathways were triggered. While AgNPs induce only apoptosis (45.98 ± 1.88%), Cisplatin induces apoptosis and necrosis at the same rate (22.31 ± 1.72% and 24.07 ± 1.10%, respectively). In addition to their antiproliferative activity, in vivo experiments showed that treatments of 3, 6, and 12 mg/kg of AgNPs elicit a survival rate almost 4 times higher (P < 0.05) compared with the survival rate obtained with Cisplatin (2 mg/kg). Furthermore, the survivor mice treated with AgNPs do not show genotoxic damage determined by micronuclei frequency quantification on peripheral blood cells. These results exhibit the remarkable antitumour activity of a nongenotoxic AgNP formulation and constitute the first advance toward the application of these AgNPs for melanoma treatment, which could considerably reduce adverse effects provoked by currently applied chemotherapeutics.


Assuntos
Melanoma Experimental/tratamento farmacológico , Nanopartículas Metálicas/uso terapêutico , Prata/química , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cisplatino/uso terapêutico , Dano ao DNA/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Estimativa de Kaplan-Meier , Masculino , Melanoma Experimental/mortalidade , Melanoma Experimental/patologia , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio/metabolismo
9.
Clin Rev Allergy Immunol ; 52(1): 125-132, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28004375

RESUMO

Gorham-Stout disease (GSD) is a rare condition of osteolysis with excessive lymphangiogenesis within bone tissue. The etiology of this condition remains unknown but seems to affect mainly children and young adults of both genders all over the world. Unfortunately, there is no standardized method for diagnosis; however, histopathology remains as the gold standard. This condition is often misdiagnosed due to its varying clinical presentations from case-to-case. Here, we report the case of an 8-year-old girl who presented with chronic mandibular pain during mastication and received multiple antibiotic treatment due to infectious origin suspicion. After integrating information from clinical manifestations, radiographic, laboratory, and histopathology information, she was diagnosed with GSD. Additionally, due to the lack of literature with respect to insights into biological mechanisms and standardized treatment for this condition, we underwent a literature revision to provide information related to activation of cells from the immune system, such as macrophages, T-cells, and dendritic cells, and their contribution to the lymphangiogenesis, angiogenesis, and osteoclastogenic process in GSD. It is important to consider these mechanisms in patients with GSD, especially since new studies performed in earlier stages are required to confirm their use as novel diagnostic tools and find new possibilities for treatment.


Assuntos
Osteólise Essencial/patologia , Criança , Feminino , Humanos , Mandíbula/anormalidades , Osteólise Essencial/diagnóstico
11.
J Toxicol ; 2016: 7934257, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26981119

RESUMO

Feminization of the agricultural labor is common in Mexico; these women and their families are vulnerable to several health risks including genotoxicity. Previous papers have presented contradictory information with respect to indirect exposure to pesticides and DNA damage. We aimed to evaluate the genotoxic effect in buccal mucosa from female farmers and children, working in the agricultural valley of Maneadero, Baja California. Frequencies of micronucleated cells (MNc) and nuclear abnormalities (NA) in 2000 cells were obtained from the buccal mucosa of the study population (n = 144), divided in four groups: (1) farmers (n = 37), (2) unexposed (n = 35), (3) farmers' children (n = 34), and (4) unexposed children (n = 38). We compared frequencies of MNc and NA and fitted generalized linear models to investigate the interaction between these variables and exposition to pesticides. Differences were found between farmers and unexposed women in MNc (p < 0.0001), CC (p = 0.3376), and PN (p < 0.0001). With respect to exposed children, we found higher significant frequencies in MNc (p < 0.0001), LN (p < 0.0001), CC (p < 0.0001), and PN (p < 0.004) when compared to unexposed children. Therefore working as a farmer is a risk for genotoxic damage; more importantly indirectly exposed children were found to have genotoxic damage, which is of concern, since it could aid in future disturbances of their health.

12.
Oral Maxillofac Surg ; 20(1): 1-7, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26556782

RESUMO

The purpose of the present article was to present a clinical case of an 11-year-old girl with peripheral ossifying fibroma (POF). Additionally, after performing a literature review, we identified clinical information that occurs more frequently in association with POF, such evidence would help professionals in yielding a specific diagnosis and tailor a more specific therapeutic approach with the objective to decrease morbidities' associated with POF. This lesion represents the third most common lesion of all localized reactive hyperplastic lesions. Clinical aspects related to this pathology include the fact that it occurs most frequently in women between the first and second decades of life. It affects anterior maxillary region and interferes with normal functioning of this anatomical structure. After conducting the literature search, we found that it can also be presented in a considerable number of males with pain and hyperemia being the most common clinical manifestations. We found that often clinical cases are presented with incomplete information. It is important that in order to get to a consensus with respect to updates about information related to this lesion, new case series that include complete clinical information, radiographic analysis, and histopathology tests could be presented.


Assuntos
Neoplasias Ósseas/diagnóstico , Fibroma Ossificante/diagnóstico , Neoplasias Maxilares/diagnóstico , Biópsia , Neoplasias Ósseas/patologia , Neoplasias Ósseas/cirurgia , Criança , Diagnóstico Diferencial , Feminino , Fibroma Ossificante/patologia , Fibroma Ossificante/cirurgia , Humanos , Masculino , Maxila/patologia , Maxila/cirurgia , Neoplasias Maxilares/patologia , Neoplasias Maxilares/cirurgia , Radiografia Panorâmica , Tomografia Computadorizada por Raios X
13.
Biomed Res Int ; 2015: 194031, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26339592

RESUMO

Autoimmune diseases (AD) are classified into organ-specific, systemic, and mixed; all forms of AD share a high risk for cancer development. In AD a destructive immune response induced by autoreactive lymphocytes is started and continues with the production of autoantibodies against different targets; furthermore apoptosis failure and loss of balance in oxidative stress as a consequence of local or systemic inflammation are common features seen in AD as well. Micronucleus (MN) assay can be performed in order to evaluate loss of genetic material in a clear, accurate, fast, simple, and minimally invasive test. The MN formation in the cytoplasm of cells that have undergone proliferation is a consequence of DNA fragmentation during mitosis and the appearance of small additional nuclei during interphase. The MN test, widely accepted for in vitro and in vivo genotoxicity research, provides a sensitive marker of genomic damage associated to diverse conditions. In here, we present a review of our work and other published papers concerning genotoxic effect in AD, identified by means of the MN assay, with the aim of proposing this tool as a possible early biomarker for genotoxic damage, which is a consequence of disease progression. Additionally this biomarker could be used for follow-up, to asses genome damage associated to therapies.


Assuntos
Doenças Autoimunes/genética , Dano ao DNA/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Testes para Micronúcleos , Neoplasias/genética , Apoptose/efeitos dos fármacos , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Carcinógenos/toxicidade , Núcleo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Mitose/efeitos dos fármacos , Mutagênicos/toxicidade , Neoplasias/induzido quimicamente , Neoplasias/patologia , Estresse Oxidativo/efeitos dos fármacos
14.
PLoS One ; 10(8): e0131548, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26244938

RESUMO

BACKGROUND: An estimated 800,000 people worldwide are occupationally exposed to welding-fumes. Previous studies show that the exposure to such fumes is associated with damage to genetic material and increased cancer risk. In this study, we evaluate the genotoxic effect of welding-fumes using the Micronucleus Test on oral mucosa cells of Mexican welders. MATERIAL AND METHODS: We conducted a cross-sectional, matched case-control study of n = 66 (33 exposed welders, and 33 healthy controls). Buccal mucosa smears were collected and stained with acridine orange, observed under 100x optical amplification with a fluorescence lamp, and a single-blinded observer counted the number of micronuclei and other nuclear abnormalities per 2,000 observed cells. We compared the frequencies of micronuclei and other nuclear abnormalities, and fitted generalised linear models to investigate the interactions between nuclear abnormalities and the exposure to welding-fumes, while controlling for smoking and age. RESULTS: Binucleated cells and condensed-chromatin cells showed statistically significant differences between cases and controls. The frequency of micronuclei and the rest of nuclear abnormalities (lobed-nuclei, pyknosis, karyolysis, and karyorrhexis) did not differ significantly between the groups. After adjusting for smoking, the regression results showed that the occurrence of binucleated cells could be predicted by the exposure to welding-fumes plus the presence of tobacco consumption; for the condensed-chromatin cells, our model showed that the exposure to welding-fumes is the only reliable predictor. CONCLUSIONS: Our findings suggest that Mexican welders who are occupationally exposed to welding-fumes have increased counts of binucleated and condensed-chromatin cells. Nevertheless, the frequencies of micronuclei and the rest of nuclear abnormalities did not differ between cases and controls. Further studies should shed more light on this subject.


Assuntos
Dano ao DNA , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Mucosa Bucal/patologia , Exposição Ocupacional/efeitos adversos , Soldagem , Estudos de Casos e Controles , Núcleo Celular , Estudos Transversais , Humanos , Masculino , México , Testes para Micronúcleos
15.
J BUON ; 19(4): 895-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25536592

RESUMO

PURPOSE: Breast cancer (BC) is the most frequently diagnosed form of cancer and the leading cause of cancer-related deaths among females in the world. RESULTS of several studies showed that the genome of primary cancer patients (naive for any treatment) is unstable. The purpose of the present study was to evaluate the genomic instability in BC patients by means of buccal cells micronucleus (MN) cytome assay Methods: The frequencies of nuclear anomalies including MN, binucleates (BN), broken eggs (BE), condensed chromatin (CC), karyorrhexis (KR) and karyolysis (KL) were evaluated in exfoliated buccal mucosa cells of Mexican women with primary BC and healthy women. Buccal cells were collected from 21 BC patients (9 with stage I and 12 with stage II) and from 20 healthy females used as control group. RESULTS: The results of the evaluation of cells showed that the frequencies of MN, BN, BE, KR and KL were significantly increased in the pooled group of BC patients compared with the control group. However, no one parameter of buccal MN-cytome assay in patients with stage I BC was significant compared with controls and BC patients with stage II. CONCLUSION: Application of the buccal MN-cytome assay for the study of genomic instability in primary BC patients showed that both genotoxic and cytotoxic effects can be evaluated in such patients.


Assuntos
Neoplasias da Mama/genética , Testes para Micronúcleos , Estudos de Casos e Controles , Núcleo Celular , Feminino , Humanos , Mucosa Bucal/citologia
16.
Clin Rev Allergy Immunol ; 47(1): 73-90, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24840362

RESUMO

Posttranslational modifications (PTMs) are defined as covalent modifications occurring in a specific protein amino acid in a time- and signal-dependent manner. Under physiological conditions, proteins are posttranslationally modified to carry out a large number of cellular events from cell signaling to DNA replication. However, an absence, deficiency, or excess in PTMs of a given protein can evolve into a target to trigger autoimmunity, since PTMs arise in the periphery and may not occur in the thymus; hence, proteins with PTMs never tolerize developing thymocytes. Consequently, when PTMs arise during cellular responses, such as inflammation, these modified self-antigens can be taken up and processed by the antigen-presenting cells (APCs). Autoreactive T cells, which recognize peptides presented by APCs, can then infiltrate into host tissue where the modified antigen serves to amplify the autoimmune response, eventually leading to autoimmune pathology. Furthermore, a PTM occurring in an amino acid residue can induce changes in the net charge of the protein, leading to conformational modifications in the tertiary and quaternary structure of the protein, especially interaction with human leukocyte antigen (HLA) molecules. Molecular mimicry (MM) was until now the prevailing hypothesis explaining generation of autoimmunity; nevertheless, experimental animal models need inflammation via infection or other immunogens to ensure autoimmunity; MM alone is not sufficient to develop autoimmunity. PTMs could arise as an additive factor to MM, which is required to start an autoimmune response. PTMs have been found to be present in different pathologic conditions such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), antiphospholipid syndrome, and primary biliary cirrhosis. The aim of the present review is to expose protein posttranslational modifications and the evidence suggesting their role in the generation of autoimmunity.


Assuntos
Autoantígenos/metabolismo , Doenças Autoimunes/imunologia , Autoimunidade , Processamento de Proteína Pós-Traducional , Animais , Apresentação de Antígeno , Autoantígenos/imunologia , Modelos Animais de Doenças , Antígenos HLA/metabolismo , Humanos , Conformação Molecular
17.
Dis Markers ; 2014: 956835, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24778463

RESUMO

The use of biomarkers as tools to evaluate genotoxicity is increasing recently. Methods that have been used previously to evaluate genomic instability are frequently expensive, complicated, and invasive. The micronuclei (MN) and nuclear abnormalities (NA) technique in buccal cells offers a great opportunity to evaluate in a clear and precise way the appearance of genetic damage whether it is present as a consequence of occupational or environmental risk. This technique is reliable, fast, relatively simple, cheap, and minimally invasive and causes no pain. So, it is well accepted by patients; it can also be used to assess the genotoxic effect derived from drug use or as a result of having a chronic disease. Furthermore the beneficial effects derived from changes in life style or taking additional supplements can also be evaluated. In the present paper, we aim to focus on the explanation of MN test and its usefulness as a biomarker; we further give details about procedures to perform and interpret the results of the test and review some factors that could have an influence on the results of the technique.


Assuntos
Dano ao DNA , Micronúcleos com Defeito Cromossômico , Mucosa Bucal/patologia , Animais , Biomarcadores , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/patologia , Núcleo Celular/efeitos da radiação , Citodiagnóstico , Humanos , Testes para Micronúcleos
19.
Int. j. morphol ; 31(2): 650-657, jun. 2013. ilus
Artigo em Espanhol | LILACS | ID: lil-687119

RESUMO

Los micronúcleos son fragmentos o cromosomas completos que quedan fuera del núcleo durante la mitosis; mediante su estudio se pueden evaluar los efectos de genotóxicos ambientales y ocupacionales. Esta prueba es ampliamente utilizada y es una alternativa eficaz, sencilla y económica para detectar la perdida de material genético. Por otra parte, la cavidad oral puede reflejar el estado de salud de los individuos, debido a que la mucosa que la recubre, puede presentar evidencias a nivel microscópico como macroscópico de cambios indicativos de enfermedad local sistémica o por exposición a sustancias tóxicas así como efectos secundarios por tratamientos. Dichas ventajas, favorecen su utilización en pruebas para evaluar genotóxicos o citotóxicos. La mucosa es una barrera protectora del resto del organismo, es un punto de contacto de agentes potencialmente peligrosos; por tanto, se torna susceptible de sufrir daños. El epitelio de revestimiento oral (60 por ciento) es estratificado no queratinizado formado por células con abundante citoplasma, permite la penetración de colorantes y facilita la observación e identificación de características morfológicas del núcleo y membrana celular. Además la mucosa tiene elevada capacidad proliferativa y aunque esta particularidad mantiene la población celular constante, por otro lado, se vuelve más vulnerable a daño al ADN. Esto cobra relevancia ya que el 90 por ciento del cáncer tienen origen epitelial, así que la mucosa oral es usada para monitorear eventos genotóxicos tempranos causados por cancerígenos inhalados o ingeridos. Este epitelio es de fácil acceso, poco invasivo, por lo que al tomar la muestra a los individuos, se les genera mínimo estrés. Por todo lo anterior, el epitelio oral es un tejido ideal para aplicar la técnica de micronúcleos y detección de anormalidades nucleares sin necesidad de cultivos celulares, lo que representa una oportunidad para realizar estudios epidemiológicos en poblaciones de alto riesgo.


Micronucleus are fragments or whole chromosomes that are outside the nucleus during mitosis. Through this study we can evaluate the environmental and occupational the genotoxic effects. This test is widely used because it is a very effective alternative, it is a simple, fast and inexpensive way to detect the loss of genetic material. Meanwhile a healthy oral cavity is evidenced because in the overlying mucosa changes indicative of local or systemic disease, toxic exposure and side effects of treatments can be observed. This favors their use in tests to assess the presence of genotoxins or cytotoxins. Although protective barrier from the rest of the body is the point of contact of potentially dangerous agents thus becoming susceptible to damage. Coating and oral epithelium (60 percent) are formed by stratified non-keratinized cells with abundant cytoplasm, allowing the absorption of dyes and facilitating microscopic observation and identification of nucleus and membrane morphological characteristics. It has a particularly proliferative capacity, and even though this particularity maintains constant cell population, on the other hand, becomes more vulnerable to DNA damage. This information is relevant as 90 percent of all cancers are of epithelial origin. Therefore, the oral mucosa is used to monitor early events caused by inhaled or ingested genotoxic carcinogens. Epithelium is easily accessible and minimally invasive, thereby generating less stress when samples are obtained from study participants. In view of the above, oral epithelium tissue is ideal for implementing micronucleus assay and for the detection of nuclear abnormalities without the need for cell cultures, which presents a unique opportunity for epidemiological studies in high-risk populations.


Assuntos
Humanos , Mucosa Bucal/citologia , Testes para Micronúcleos/métodos , Testes de Mutagenicidade
20.
Artigo em Inglês | MEDLINE | ID: mdl-20390845

RESUMO

This study is a follow-up of previous research in which we described the frequency of spontaneous micronucleated erythrocytes (MNE) in the Goodeid Xenotocoa melanosoma collected from Lake La Alberca, located in the state of Michoacan, Mexico. In the present work, we measured micronuclei (MN) and nuclear abnormalities (NA) in erythrocytes of peripheral blood. Bioassays taken at 24 or 96 hours in either the cyclophosfamide (CP) or colchicine (COL) showed a significant increase in MN and BC (P values ranging from 0.0499 to 0.0036) compared with information from wild organisms collected over 3 years. Concentrationdependent and time-dependent responses support the proposal of using endemic Xenotoca melanosoma as a bioindicator of genotoxicity and cytotoxicity with a high transcendence for the health of the entire ecosystem and evaluation of the Lerma-Chapala watershed.


Assuntos
Aneugênicos/toxicidade , Colchicina/toxicidade , Ciclofosfamida/toxicidade , Ciprinodontiformes , Eritroblastos/efeitos dos fármacos , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Mutagênicos/toxicidade , Animais , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/patologia , Relação Dose-Resposta a Droga , Monitoramento Ambiental , Eritroblastos/fisiologia , Feminino , Água Doce , Masculino , México , Testes para Micronúcleos
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