PDF(Pubmed)
Abstract：
The increasing use of nanomaterials in a variety of industrial, commercial, medical products, and their environmental spreading has raised concerns regarding their potential toxicity on human health. Titanium dioxide nanoparticles (TiO2 NPs) represent one of the most commonly used nanoparticles. Emerging evidence suggested that exposure to TiO2 NPs induced reproductive toxicity in male animals. In this in vitro study, porcine prepubertal Sertoli cells (SCs) have undergone acute (24 h) and chronic (from 1 up to 3 weeks) exposures at both subtoxic (5 µg/ml) and toxic (100 µg/ml) doses of TiO2 NPs. After performing synthesis and characterization of nanoparticles, we focused on SCs morphological/ultrastructural analysis, apoptosis, and functionality (AMH, inhibin B), ROS production and oxidative DNA damage, gene expression of antioxidant enzymes, proinflammatory/immunomodulatory cytokines, and MAPK kinase signaling pathway. We found that 5 µg/ml TiO2 NPs did not induce substantial morphological changes overtime, but ultrastructural alterations appeared at the third week. Conversely, SCs exposed to 100 µg/ml TiO2 NPs throughout the whole experiment showed morphological and ultrastructural modifications. TiO2 NPs exposure, at each concentration, induced the activation of caspase-3 at the first and second week. AMH and inhibin B gene expression significantly decreased up to the third week at both concentrations of nanoparticles. The toxic dose of TiO2 NPs induced a marked increase of intracellular ROS and DNA damage at all exposure times. At both concentrations, the increased gene expression of antioxidant enzymes such as SOD and HO-1 was observed whereas, at the toxic dose, a clear proinflammatory stress was evaluated along with the steady increase in the gene expression of IL-1α and IL-6. At both concentrations, an increased phosphorylation ratio of p-ERK1/2 was observed up to the second week followed by the increased phosphorylation ratio of p-NF-kB in the chronic exposure. Although in vitro, this pilot study highlights the adverse effects even of subtoxic dose of TiO2 NPs on porcine prepubertal SCs functionality and viability and, more importantly, set the basis for further in vivo studies, especially in chronic exposure at subtoxic dose of TiO2 NPs, a condition closer to the human exposure to this nanoagent.
摘要：
纳米材料在各种工业中的使用越来越多,商业,医疗产品,它们在环境中的传播引起了人们对它们对人类健康的潜在毒性的担忧。二氧化钛纳米颗粒(TiO2纳米颗粒)代表最常用的纳米颗粒之一。新出现的证据表明，暴露于TiO2NP会引起雄性动物的生殖毒性。在这项体外研究中，在亚毒性（5µg/ml）和毒性（100µg/ml）剂量的TiO2NPs下，猪青春期前睾丸支持细胞（SC）经历了急性（24小时）和慢性（1至3周）暴露。在进行纳米粒子的合成和表征后，我们专注于SCs形态学/超微结构分析，凋亡，和功能(AMH，抑制素B),ROS产生和氧化DNA损伤，抗氧化酶的基因表达，促炎/免疫调节细胞因子，和MAPK激酶信号通路。我们发现，5µg/mlTiO2NPs不会随时间引起实质性的形态变化，但是超微结构改变出现在第三周。相反，在整个实验中，暴露于100µg/mlTiO2NP的SC显示出形态和超微结构的改变。TiO2NPs暴露，在每个浓度，在第一周和第二周诱导caspase-3的激活。在两种纳米颗粒浓度下,AMH和抑制素B基因表达显著降低直至第3周。TiO2NP的毒性剂量在所有暴露时间均导致细胞内ROS和DNA损伤的显着增加。在两种浓度下，抗氧化酶如SOD和HO-1的基因表达增加，在毒性剂量下，随着IL-1α和IL-6基因表达的稳定增加，评估了明显的促炎应激。在两种浓度下，直至第2周,观察到p-ERK1/2的磷酸化比率增加,随后在慢性暴露中p-NF-kB的磷酸化比率增加.虽然在体外，这项初步研究强调了即使是亚毒性剂量的TiO2NPs对猪青春期前SCs功能和活力的不利影响，更重要的是,为进一步的体内研究奠定基础，特别是在亚毒性剂量的TiO2NPs的慢性暴露中，更接近人类暴露于这种纳米剂的情况。
