RESUMO
Exposure to TiO2 NPs induces several cellular alterations after NPs uptake including disruption of cytoskeleton that is crucial for lung physiology but is not considered as a footprint of cell damage. We aimed to investigate cytoskeleton disturbances and the impact on cell migration induced by an acute TiO2 NPs exposure (24 h) and the recovery capability after 6 days of NPs-free treatment, which allowed investigating if cytoskeleton damage was reversible. Exposure to TiO2 NPs (10 µg/cm2) for 24 h induced a decrease 20.2% and 25.1% in tubulin and actin polymerization. Exposure to TiO2 NPs (10 µg/cm2) for 24 h followed by 6 days of NPs-free had a decrease of 26.6% and 21.3% in tubulin and actin polymerization, respectively. The sustained exposure for 7 days to 1 µg/cm2 and 10 µg/cm2 induced a decrease of 22.4% and 30.7% of tubulin polymerization respectively, and 28.7% and 46.2% in actin polymerization. In addition, 24 h followed 6 days of NPs-free exposure of TiO2 NPs (1 µg/cm2 and 10 µg/cm2) decreased cell migration 40.7% and 59.2%, respectively. Cells exposed (10 µg/cm2) for 7 days had a decrease of 65.5% in cell migration. Ki67, protein surfactant B (SFTPB) and matrix metalloprotease 2 (MMP2) were analyzed as genes related to lung epithelial function. The results showed a 20% of Ki67 upregulation in cells exposed for 24 h to 10 µg/cm2 TiO2 NPs while a downregulation of 20% and 25.8% in cells exposed to 1 µg/cm2 and 10 µg/cm2 for 24 h followed by 6 days of NPs-free exposure. Exposure to 1 µg/cm2 and 10 µg/cm2 for 24 h and 7 days upregulates SFTPB expression in 53% and 59% respectively, MMP2 expression remain unchanged. In conclusion, exposure of TiO2 NPs affected cytoskeleton of lung epithelial cells irreversibly but this damage was not cumulative.
Assuntos
Citoesqueleto/patologia , Células Epiteliais/patologia , Pulmão/patologia , Nanopartículas/toxicidade , Titânio/toxicidade , Células A549 , Actinas/metabolismo , Movimento Celular/efeitos dos fármacos , Tamanho Celular , Sobrevivência Celular/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Endocitose , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/ultraestrutura , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Antígeno Ki-67/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Nanopartículas/ultraestrutura , Polimerização , Precursores de Proteínas/metabolismo , Proteínas Associadas a Surfactantes Pulmonares/metabolismo , Tubulina (Proteína)/metabolismoRESUMO
Food-grade titanium dioxide labeled as E171 has been approved for human consumption by the Food and Drug Administration (USA) and by the European Union for five decades. However, titanium dioxide has been classified as a possible carcinogen for humans by the International Agency of Research in Cancer raising concerns of its oral intake and the translocation to bloodstream, which could disturb barriers such as the blood-testis barrier. There is evidence that titanium dioxide by intragastric/intraperitoneal/intravenous administration induced alterations on testosterone levels, testicular function and architecture, but studies of the E171 effects on the testicle structure and blood-testis barrier are limited. E171 is contained not only in foods in liquid matrix but also in solid ones, which can exert different biological effects. We aimed to compare the effects of E171 consumption in a solid matrix (0.1%, 0.5% and 1% in pellets) and liquid suspension (5 mg/kg body weight) on testis structure, inflammation infiltrate and blood-testis barrier disruption of male BALB/c mice. Results showed that none of the administration routes had influence on body weight but an increase in germ cell sloughing and the infiltrate of inflammatory cells in seminiferous tubules, together with disruption of the blood-testis barrier were similar in testis of both groups even if the dose received in mice in liquid matrix was 136 or 260 times lower than the dose reached by oral intake in solid E171 pellets in 0.5% E171 and 1% E171, respectively. This study highlights the attention on matrix food containing E171 and possible adverse effects on testis when E171 is consumed in a liquid matrix.
Assuntos
Barreira Hematotesticular/efeitos dos fármacos , Aditivos Alimentares , Nanopartículas Metálicas/toxicidade , Epitélio Seminífero/efeitos dos fármacos , Células de Sertoli/efeitos dos fármacos , Titânio/toxicidade , Ração Animal/análise , Animais , Barreira Hematotesticular/imunologia , Barreira Hematotesticular/patologia , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Água Potável/química , Ingestão de Alimentos/efeitos dos fármacos , Aditivos Alimentares/toxicidade , Antígenos de Histocompatibilidade Classe II/imunologia , Masculino , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Camundongos , Camundongos Endogâmicos BALB C , Tamanho da Partícula , Epitélio Seminífero/imunologia , Epitélio Seminífero/patologia , Túbulos Seminíferos/efeitos dos fármacos , Túbulos Seminíferos/imunologia , Túbulos Seminíferos/ultraestrutura , Células de Sertoli/imunologia , Células de Sertoli/ultraestrutura , Propriedades de Superfície , Titânio/administração & dosagem , Titânio/químicaRESUMO
Titanium dioxide nanoparticles (TiO2 NPs) production has been used for pigment, food and cosmetic industry and more recently, shaped as belts for treatment of contaminated water, self-cleaning windows and biomedical applications. However, the toxicological data have demonstrated that TiO2 NPs inhalation induce inflammation in in vivo models and in vitro exposure leads to cytotoxicity and DNA damage. Dermal exposure has limited adverse effects and the possible risks for implants used for tissue regeneration is still under research. Then, it has been difficult to establish a straight statement about TiO2 NPs toxicity since route of exposure and shapes of nanoparticles play an important role in the effects. In this study we aimed to investigate the effect of three different types of TiO2 NPs (industrial, food-grade and belts) dispersed in fetal bovine serum (FBS) and saline solution (SS) on microvessel network, angiogenesis gene expression and femur ossification using a chick embryo model after an acute exposure of NPs on the day 7 after eggs fertilization. Microvascular density of chorioallantoic membrane (CAM) was analyzed after 7days of NPs injection and vehicles induced biological effects per se. NPs dispersed in FBS or SS have slight differences in microvascular density, mainly opposite effect on angiogenesis gene expression and no effects on femur ossification for NPs dispersed in SS. Interestingly, NPs shaped as belts dramatically prevented the alterations in ossification induced by FBS used as vehicle.
Assuntos
Membrana Corioalantoide/efeitos dos fármacos , Fêmur/efeitos dos fármacos , Nanopartículas Metálicas/química , Neovascularização Fisiológica/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Titânio/farmacologia , Animais , Biomarcadores/metabolismo , Bovinos , Embrião de Galinha , Membrana Corioalantoide/irrigação sanguínea , Membrana Corioalantoide/metabolismo , Fêmur/crescimento & desenvolvimento , Fêmur/metabolismo , Feto , Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/ultraestrutura , NF-kappa B/genética , NF-kappa B/metabolismo , Osteogênese/genética , Tamanho da Partícula , Titânio/sangue , Titânio/química , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , ZigotoRESUMO
Colorectal cancer is the fourth worldwide cause of death and even if some dietary habits are consider risk factors, the contribution of food additives including foodgrade titanium dioxide (TiO2), designated as E171, has been poorly investigated. We hypothesized that oral E171 intake could have impact on the enhancement of colorectal tumor formation and we aimed to investigate if E171 administration could enhance tumor formation in a colitis associated cancer (CAC) model. BALB/c male mice were grouped as follows: a) control, b) E171, c) CAC and d) CAC + E171 group (n = 6). E171 used in this study formed agglomerates of 300 nm in water. E171 intragastric administration (5 mg/kg body weight/5 days/10 weeks) was unable to induce tumor formation but dysplastic alterations were observed in the distal colon but enhanced the tumor formation in distal colon (CAC + E171 group) measured by tumor progression markers. Some E171 particles were internalized in colonic cells of the E171 and CAC + E171 groups and both groups showed a decrease in goblet cells in the distal colon. However the CAC + E171 group showed a higher decrease of these cells that act as protection barrier in colon. These results suggest that E171 could worsen pre-existent intestinal diseases.
Assuntos
Colite/complicações , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Aditivos Alimentares/toxicidade , Células Caliciformes/patologia , Titânio/toxicidade , Animais , Células Cultivadas , Colite/tratamento farmacológico , Neoplasias Colorretais/induzido quimicamente , Células Caliciformes/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Titanium dioxide nanoparticles (TiO2 NPs) studies have been performed using relatively high NPs concentration under acute exposure and limited studies have compared shape effects. We hypothesized that midterm exposure to low TiO2 NPs concentration in lung epithelial cells induces carcinogenic characteristics modulated partially by NPs shape. To test our hypothesis we synthesized NPs shaped as belts (TiO2-B) using TiO2 spheres (TiO2-SP) purchased from Sigma Aldrich Co. Then, lung epithelial A549 cells were low-exposed (10 µg/cm(2)) to both shapes during 7 days and internalization, cytokine release and invasive potential were determined. Results showed greater TiO2-B effect on agglomerates size, cell size and granularity than TiO2-SP. Agglomerates size in cell culture medium was 310 nm and 454 nm for TiO2-SP and TiO2-B, respectively; TiO2-SP and TiO2-B induced 23% and 70% cell size decrease, respectively, whilst TiO2-SP and TiO2-B induced 7 and 14-fold of granularity increase. NOx production was down-regulated (31%) by TiO2-SP and up-regulated (70%) by TiO2-B. Both NPs induced a transient cytokine release (IL-2, IL-6, IL-8, IL-4, IFN-γ, and TNF-α) after 4 days, but cytokines returned to basal levels in TiO2-SP exposed cells while TiO2-B induced a down-regulation after 7 days. Midterm exposure to both shapes of NPs induced capability to degrade cellular extracellular matrix components from chorioallantoic membrane and Ki-67 marker showed that TiO2-B had higher proliferative potential than TiO2-SP. We conclude that midterm exposure to low NPs concentration of NPs has an impact in the acquisition of new characteristics of exposed cells and NPs shape influences cellular outcome.