RESUMO
Objective: Phthalates, which are commonly used to render plastics into soft and flexible materials, have also been determined as developmental and reproductive toxicants in human and animals. The purpose of this study was to evaluate the effect of mono-[2-ethylhexyl] phthalate [MEHP] and di-[2-ethylhexyl] phthalate [DEHP] oral administrations on maturation of mouse oocytes, apoptosis and gene transcription levels
Materials and Methods: In this experimental study, immature oocytes recovered from Naval Medical Research Institute [NMRI] mouse strain [6-8 weeks], were divided into seven different experimental and control groups. Control group oocytes were retrieved from mice that received only normal saline. The experimental groups I, II or III oocytes were retrieved from mice treated with 50, 100 or 200 micro l DEHP [2.56 micro M] solution, respectively. The experimental groups IV, V or VI oocytes were retrieved from mouse exposed to 50, 100 or 200 micro l MEHP [2.56 micro M] solution, respectively. Fertilization and embryonic development were carried out in OMM and T6 medium. Apoptosis was assessed by annexin V-FITC/Dead Cell Apoptosis Kit, with PI staining. In addition, the mRNA levels of Pou5f1, Ccna1 and Asah1 were examined in oocytes. Finally, mouse embryo at early blastocyst stage was stained with acridine-orange [AO] and ethidium-bromide [EB], in order to access their viability
Results: The proportion of oocytes that progressed up to metaphase II [MII] and 2-cells embryo formation stage was significantly decreased by exposure to MEHP or DEHP, in a dose-dependent manner. Annexin V and PI positive oocytes showed greater quantity in the treated mice than control. Quantitative reverse transcriptase-polymerase chain reaction [qRT-PCR] revealed that expression levels of Pou5f1, Asah1 and Ccna1 were significantly lower in the treated mouse oocytes than control. The total cell count for blastocyst developed from the treated mouse oocytes was lower than the controls
Conclusion: These results indicate that oral administration of MEHP and DEHP could negatively affect mouse oocyte meiotic maturation and development in vivo, suggesting that phthalates could be risk factors for mammalians' reproductive health. Additionally, phthalate-induced changes in Pou5f1, Asah1 and Ccna1 transcription level could explain in part, the reduced developmental ability of mouse-treated oocytes
Assuntos
Animais de Laboratório , Dietilexilftalato/efeitos adversos , Recuperação de Oócitos , Modelos Animais , Meiose/efeitos dos fármacos , Perfilação da Expressão Gênica , ApoptoseRESUMO
Objective: To evaluate the effect of Exendine-4 [EX-4], a Glucagon-like peptide 1 [GLP-1] receptor agonist, on the differentiation of insulin-secreting cells [IPCs] from rat adipose-derived mesenchymal stem cells[ADMSCs]
Materials and Methods: In this experimental study, ADMSCs were isolated from rat adipose tissue and exposed to induction media with or without EX-4. After induction, the existence of IPCs was confirmed by morphology analysis, expression pattern analysis of islet-specific genes [Pdx-1, Glut-2 and Insulin] and insulin synthesis and secretion
Results: IPCs induced in presence of EX-4 were morphologically similar to pancreatic islet-like cells. Expression of Pdx-1, Glut-2 and Insulin genes in EX-4 treated cells was significantly higher than the cells exposed to differentiation media without EX-4. Compared to EX-4 untreated ADMSCs, insulin release from EX-4 treated ADMSCs showed a nearly 2.5 fold [P<0.05] increase when exposed to a high glucose [25 mM] medium. The percentage of insulin positive cells in the EX-4 treated group was approximately 4-fold higher than in the EX-4 untreated ADMSCs
Conclusion: The present study has demonstrated that EX-4 enhances the differentiation of ADMSCs into IPCs. Improvement of this method may help the formation of an unlimited source of cells for transplantation
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Objective: Zinc oxide nanoparticles [ZnO-NPs] are increasingly used in sunscreens, biosensors, food additives, pigments, manufacture of rubber products, and electronic materials. There are several studies about the effects of NPs on dermal fibroblast or keratinocytes, but very little attention has been directed towards adipose-derived mesenchymal stem cells [ASCs]. A previous study has revealed that ZnO-NPs restricted the migration capability of ASCs. However, the potential toxicity of these NPs on ASCs is not well understood. This study intends to evaluate the effects of ZnO-NPs on subcutaneous ASCs
Materials and Methods: In this experimental study, In order to assess toxicity, we exposed rat ASCs to ZnO-NPs at concentrations of 10, 50, and 100 Mug/ml for 48 hours. Toxicity was evaluated by cell morphology changes, cell viability assay, as well as apoptosis and necrosis detection
Results: ZnO-NPs concentration dependently reduced the survival rates of ASCs as revealed by the trypan blue exclusion and 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium-bromide [MTT] tests. ZnO-NPs, at concentrations of 10 and 50 Mug/ml, induced a significant increase in apoptotic indices as shown by the annexin V test. The concentration of 10 Mug/ml of ZnO-NPs was more toxic
Conclusion: Lower concentrations of ZnO-NPs have toxic and apoptotic effects on subcutaneous ASCs. We recommend that ZnO-NPs be used with caution if there is a dermatological problem