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Exposure to lanthanoids (Ln) elicits an adverse response such as oxidative injury of lung in animals and human. The molecular targets of Ln remain unclear. In the present study, the function and signal pathway of nuclear factor erythroid 2 related factor 2 (Nrf2) in LaCl3 -induced oxidative stress in mouse lung were investigated. Mice were exposed to 2, 5, and 10 mg/kg body weight by nasal administration for 6 consecutive months. With increased doses, La was markedly accumulated and promoted the reactive oxygen species (ROS) production in the lung, which in turn resulted in peroxidation of lipids, proteins and DNA, and severe pulmonary damages. Furthermore, LaCl3 exposure could significantly increase levels of Nrf2, heme oxygenase 1 (HO-1) and glutamate-cysteine ligase catalytic subunit (GCLC) expressions in the LaCl3 -exposed lung. These findings imply that the induction of Nrf2 expression is an adaptive intracellular response to LaCl3 -induced oxidative stress in mouse lung, and that Nrf2 may regulate the LaCl3 -induced pulmonary damages., (© 2013 Wiley Periodicals, Inc.)

Nanoparticulate titanium dioxide (nano-TiO2 ) is a widely used powerful nanoparticulate material with high stability, anticorrosion, and photocatalytic property. However, it is possible that during nano-TiO2 exposure, there may be negative effects on cardiovascular system in intoxicated mice. The present study was therefore undertaken to determine nano-TiO2 -induced oxidative stress and to determine whether nano-TiO2 intoxication alters the antioxidant system in the mouse heart exposed to 2.5, 5, and 10 mg/kg body weight nano-TiO2 for 90 consecutive days. The findings showed that long-term exposure to nano-TiO2 resulted in obvious titanium accumulation in heart, in turn led to sparse cardiac muscle fibers, inflammatory response, cell necrosis, and cardiac biochemical dysfunction. Nano-TiO2 exposure promoted remarkably reactive oxygen species production such as superoxide radicals, hydrogen peroxide, and increased malondialdehyde, carbonyl and 8-OHdG levels as degradation products of lipid, protein, and DNA peroxidation in heart. Furthermore, nano-TiO2 exposure attenuated the activities of antioxidative enzymes, such as superoxide dismutase, ascorbate peroxidase, glutathione reductase, glutathione-S-transferase, and levels of antioxidants including ascorbic acid, glutathione, and thiol in heart. Therefore, TiO2 NPs exposure may impair cardiovascular system in mice, and attention should be aroused on the application of nano-TiO2 and their potential long-term exposure effects especially on human beings., (Copyright © 2013 Wiley Periodicals, Inc.)

Numerous studies have demonstrated that the brain is one of the target organs in acute or chronic titanium dioxide (TiO2) nanoparticles (NPs) toxicity, and oxidative stress plays an important role in this process. However, whether brain oxidative injury responds to TiO2 NPs by activating the P38-nuclear factor-E2-related factor-2 (Nrf-2) pathway is not fully understood. The present study aimed to examine activation of the P38-Nrf-2 signaling pathway associated with oxidative stress in the mouse brain induced by intranasal administration of TiO2 NPs for 90 consecutive days. Our findings indicate that TiO2 NPs caused overproliferation of spongiocytes and hemorrhage in the mouse brain. Furthermore, TiO2 NPs significantly activated p38, c-Jun N-terminal kinase, nuclear factor kappa B, Nrf-2 and heme oxygenase-1 expression in the brain, which in turn, led to increased production of reactive oxygen species, as well as lipid, protein and DNA peroxidation. These findings suggest that TiO2 NPs-induced oxidative damage in the mouse brain may occur via the p38-Nrf-2 signaling pathway. Therefore, application of TiO2 NPs in the environment should be performed with caution., (Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.)

Exposure to titanium dioxide nanoparticles (TiO(2) NPs) elicits an adverse response such as oxidative damage. The molecular targets of TiO(2) NPs remain largely unidentified. In the present study, the function and signal pathway of nuclear factor erythroid 2 related factor 2 (Nrf2) in protection against TiO(2) NPs-induced oxidative stress in the mouse lung were investigated. Mice were exposed to 10 mg/kg body weight by an intratracheal administration for 15-90 days. With increasing exposed terms, TiO(2) NPs were significantly accumulated and increased the reactive oxygen species (ROS) production in lung, which resulted in severe pulmonary edema, inflammatory response and pneumonocyte apoptosis for 90 days. Furthermore, TiO(2) NPs exposure could greatly induce expression of Nrf2, heme oxygenase 1 (HO-1), and glutamate-cysteine ligase catalytic subunit (GCLC) from 15-day to 75-day exposure, whereas 90-day exposure caused significant decreases of three factors expression levels in lung. Our findings imply that the induction of Nrf2 expression is an adaptive intracellular response to TiO(2) NPs-induced oxidative stress in the mouse lung, and that Nrf2 is protective against TiO(2) NPs-induced pulmonary damages during certain exposure terms., (Copyright © 2012 Wiley Periodicals, Inc.)

ABSTRACT It has been demonstrated that the organic damages of animals can be caused by exposure to lanthanide oxides or compounds. However, the molecular mechanism of CeCl3-induced kidney injury remains unclear. In this study, the mechanism of nephric damage in mice induced by an intragastric administration of CeCl3 was investigated. The results showed that Ce3+ was accumulated in the kidney, which in turn led to oxidative stress, severe nephric inflammation, and dysfunction in mice. Furthermore, CeCl3 activated nucleic factor κB, which in turn increased the expression levels of tumor necrosis factor α, macrophage migration inhibitory factor, interleukin-2, interleukin-4, interleukin-6, interleukin-8, interleukin-10, interleukin-18, interleukin-1β, cross-reaction protein, transforming growth factor-β, interferon-γ, and CYP1A1, while suppressed heat shock protein 70 expression. These findings implied that Ce3+-induced kidney injury of mice might be associated with oxidative stress, alteration of inflammatory cytokine expression, and reduction of detoxification of CeCl3. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1420-1427, 2014. [ABSTRACT FROM AUTHOR]

Numerous studies have demonstrated lanthanide (Ln) accumulation in the liver, and the corresponding damage; however, very little work has been done to evaluate the relationship between Ln-induced liver injury and its gene expression profile in mice. In this study, liver injury and gene-expressed profiles in male mice induced by oral administration of CeCl3 (2 mg/kg) via gavage for 90 consecutive days were investigated. The results showed that cerium accumulation, liver inflammation, and hepatocyte necrosis were observed. CeCl3 exposure significantly decreased the counts of white blood cells, lymphocyte, and platelet, the reticulocyte count (Ret) and neutrophilic granulocyte percentages as well as A/G ratio, whereas markedly increased the activities of alkaline phosphatase, lactate dehydrogenase, and cholinesterase, and the concentrations of triglycerides and total cholesterol. Furthermore, microarray results of liver showed that the differential expression of 675 known function genes involved in immune/inflammation response, apoptosis, metabolic process, cell cycle, cell proliferation, cytoskeleton, oxidative stress, signal transduction, transcription, translation, and transportation in CeCl3 exposed livers, respectively. Specifically, the significant downregulation of Nt5e led to inflammation, overexpressed Cyp4a12a and great suppression of Cdkn1a resulted in hepatocyte apoptosis, marked elevation of Cel, and Cyp7b1 expression caused the metabolic disorders in mouse liver after long-term CeCl3 exposure. Therefore, these genes may be in great relation to liver damages induced by exposure to CeCl3. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 837-846, 2014. [ABSTRACT FROM AUTHOR]

Cerium is widely used in many aspects of modern society, including agriculture, industry and medicine. It has been demonstrated to enter the ecological environment, is then transferred to humans through food chains, and causes toxic actions in several organs including the brain of animals. However, the neurotoxic molecular mechanisms are not clearly understood. In this study, mice were exposed to 0.5, 1, and 2 mg/kg BW cerium chloride (CeCl3) for 90 consecutive days, and their learning and memory ability as well as hippocampal gene expression profile were investigated. Our findings suggested that exposure to CeCl3 led to hippocampal lesions, apoptosis, oxidative stress and impairment of spatial recognition memory. Furthermore, microarray data showed marked alterations in the expression of 154 genes involved in learning and memory, immunity and inflammation, signal transduction, apoptosis and response to stress in the 2 mg/kg CeCl3 exposed hippocampi. Specifically, the significant up-regulation of Axud1, Cdc37, and Ube2v1 caused severe apoptosis, and great suppression of Adcy8, Fos, and Slc5a7 expression led to impairment of mouse cognitive ability. Therefore, Axud1, Cdc37, Ube2v1, Adcy8, Fos, and Slc5a7 may be potential biomarkers of hippocampal toxicity caused by CeCl3 exposure. [ABSTRACT FROM AUTHOR]

Abstract: Exposure to titanium dioxide nanoparticles (TiO2 NPs) has been demonstrated to result in pulmonary inflammation in animals; however, very little is known about the molecular mechanisms of pulmonary injury due to TiO2 NPs exposure. The aim of this study was to evaluate the oxidative stress and molecular mechanism associated with pulmonary inflammation in chronic lung toxicity caused by the intratracheal instillation of TiO2 NPs for 90 consecutive days in mice. Our findings suggest that TiO2 NPs are significantly accumulated in the lung, leading to an obvious increase in lung indices, inflammation and bleeding in the lung. Exposure to TiO2 NPs significantly increased the accumulation of reactive oxygen species and the level of lipid peroxidation, and decreased antioxidant capacity in the lung. Furthermore, TiO2 NPs exposure activated nuclear factor-κB, increased the levels of tumor necrosis factor-α, cyclooxygenase-2, heme oxygenase-1, interleukin-2, interleukin-4, interleukin-6, interleukin-8, interleukin-10, interleukin-18, interleukin-1β, and CYP1A1 expression. However, TiO2 NPs exposure decreased NF-κB-inhibiting factor and heat shock protein 70 expression. Our results suggest that the generation of pulmonary inflammation caused by TiO2 NPs in mice is closely related to oxidative stress and the expression of inflammatory cytokines. [Copyright &y& Elsevier]

Highlights: [•] Exposure to lanthanides impaired renal function in mice. [•] Exposure to lanthanides induced cell necrosis in kidney. [•] Exposure to lanthanides promoted ROS accumulation in kidney. [•] Exposure to lanthanides caused the reduction of antioxidant capacity in kidney. [•] The order of kidney damages was Ce exposure>Nd exposure>La exposure. [Copyright &y& Elsevier]

Abstract: Although numerous studies have described the accumulation of titanium dioxide nanoparticles (TiO2 NPs) in the liver, kidneys, lung, spleen, and brain, and the corresponding damage, it is unclear whether or not TiO2 NPs can be translocated to the ovary and cause ovarian injury, thus impairing fertility. In the current study, ovarian injury and gene-expressed characteristics in female mice induced by intragastric administration of TiO2 NPs (10mg/kg) for 90 consecutive days were investigated. Our findings indicated that TiO2 NPs can accumulate in the ovary and result in ovarian damage, cause an imbalance of mineral element distribution and sex hormones, decrease fertility or the pregnancy rate and oxidative stress in mice. Microarray analysis showed that in ovaries from mice treated with TiO2 NPs compared to controls, 223 genes of known function were up-regulated, while 65 ovarian genes were down-regulated. The increased expression of Cyp17a1 following TiO2 NPs treatment suggested that the increase in estradiol biosynthesis may be a consequence of increased TiO2 NPs. In addition, the elevated expression of Akr1c18 implied that progesterone metabolism was accelerated, thus causing a decrease in the progesterone concentration. Taken together, the apparent regulation of key ovarian genes supports the hypothesis that TiO2 NPs directly affects ovarian function. [Copyright &y& Elsevier]