Titanium dioxide nanoparticles and carbon nanotubes as potential stimulators of asthmatic reaction Studies in mouse model and cell culture

The rising productions of engineered nanomaterials (ENMs) increase the risk for harmful exposure in occupational environments. Titanium dioxide nanoparticles (TiO2 NPs) and its derivatives are abundantly used in a number of medical and industrial applications. Previous studies revealed that there is increasing number of individuals with respiratory disorders when such normal individuals are exposed to these particles in vocational settings. However, little is known about how these particles affect the preexisting airway diseases such as asthma. In order to improve the understanding, we performed an ovalbumin (OVA)-induced mouse model of allergic airway inflammation. Control and asthmatic female BALB/c mice received TiO2 NPs (21 nm) intranasally. Local tissue effects and lung function were measured primarily. Further, nanoparticle distribution into extrapulmonary organs was investigated by inductively coupled plasma mass spectrometry (ICP-MS), and scanning electron microscopy (SEM). Th1/Th2 cytokine levels were also measured in the lungs by ELISA. Our findings indicate that mice receiving OVA with TiO2 NPs developed an asthma‐like airway reaction, and enhanced eosinophil infiltration in the lung tissues of asthmatic mice compared to controls. We also found a significant increase in Th2 cytokines including Interleukin (IL) IL-4, IL 5 and IL-13 following TiO2 NP exposure. Adherent mouse alveolar macrophages were able to take up TiO2 NPs at different time points. Using SEM and ICP‐MS, we detected the nanoparticle in most of the organs of asthmatic and non-asthmatic treated mice. Next, we performed in vitro study in order to describe the toxicity of another range of nanomaterials. Three different configurations of carbon nanotubes (CNTs) including single walled carbon nanotubes (SWCNT), double walled carbon nanotubes (DWCNT), and multi walled carbon nanotubes (MWCNT) were incubated with human pulmonary epithelial cells (A549). Supernatants 7 of epithelial cell cultures were collected in order to detect the release of IL-8 and lactate dehydrogenase (LDH) by pulmonary epithelial cells. Emission scanning electron microscope (ESEM) was employed to characterize the CNTs, and to assess the modifications on the cellular surface following the exposure to the three different types of CNTs. Our results revealed the distinct differences in the levels of inflammatory response, the cellular damage, and toxicity caused by CNTs (release of LDH). Images taken by ESEM showed nanotube agglomerates and morphological changes after cellular incubation with SWCNT, DWCNT, and MWCNTs. Our data clarify the underlying mechanism of Titanium dioxide nanoparticles-induced aggravation of respiratory diseases and this suggests important implications for environmental and occupational health policy, as well as for workers and individuals exposed to these nanomaterials.Die steigende Produktion von technischen Nanomaterialien (ENMs) erhöht das Risiko einer schädlichen Exposition im beruflichen Umfeld. Titandioxid-Nanopartikel (TiO2 NPs) und seine Derivate werden in zahlreichen medizinischen und industriellen Anwendungen eingesetzt. Frühere Studien haben gezeigt, dass die Zahl der Personen mit Atemwegserkrankungen zunimmt, wenn solche Personen im beruflichen Umfeld diesen Partikeln ausgesetzt sind. Es ist jedoch wenig darüber bekannt, wie diese Partikel die bereits bestehenden Atemwegserkrankungen wie Asthma beeinflussen. Um das Verständnis zu verbessern, führten wir ein Ovalbumin (OVA)-induziertes Mausmodell für allergische Atemwegsentzündungen durch. Kontroll- und asthmatische weibliche BALB/c Mäuse erhielten intranasal TiO2 NPs (21 nm). Es wurden lokale Gewebeeffekte und die Lungenfunktion gemessen. Auch wurde die Verteilung von Nanopartikeln in extrapulmonalen Organen durch induktiv gekoppelte Plasmamassenspektrometrie (ICP-MS) und Rasterelektronenmikroskopie (SEM) untersucht. Der Th1/Th2-Zytokinspiegel wurde in den Mauslungen mittels ELISA gemessen. Unsere Ergebnisse zeigen, dass die Mäuse, die OVA mit TiO2-NPs erhielten, eine asthmaähnliche Atemwegsreaktion entwickelten und die Infiltration mit Eosinophilen im Lungengewebe der asthmatischen Mäuse im Vergleich zu den Kontrolltieren verstärkt war. Auch gab es einen signifikanten Anstieg der Th2-Zytokine, einschließlich der Interleukine (IL) IL-4, IL-5 und IL-13 nach TiO2 NP-Exposition. Alveolarmakrophagen der Mäuse konnten zu verschiedenen Zeitpunkten TiO2 NPs aufnehmen. Mit Hilfe von SEM und ICP-MS konnten die Nanopartikel in den meisten Organen der asthmatischen und nicht asthmatischen Mäuse nachgewiesen werden. Als nächstes führten wir eine In-vitro-Studie durch, um die Toxizität einer weiteren Reihe von Nanomaterialien zu beschreiben. Drei verschiedene Konfigurationen von Kohlenstoffnanoröhren (CNTs), einschließlich einwandiger Kohlenstoffnanoröhren (SWCNT), doppelwandiger Kohlenstoffnanoröhren (DWCNT) und mehrwandiger Kohlenstoffnanoröhren (MWCNT) wurden mit humanen Lungenepithelzellen (A549) inkubiert. Die Überstände von Epithelzellkulturen wurden gesammelt, um die Freisetzung von IL-8 und Lactatdehydrogenase (LDH) durch Lungenepithelzellen nachzuweisen. Das Rasterelektronenmikroskop (SEM) wurde verwendet, um die CNTs zu charakterisieren und die Veränderungen auf der Zelloberfläche nach der Exposition gegenüber den drei verschiedenen Arten von CNTs zu bewerten. Unsere Ergebnisse zeigten deutliche Unterschiede im Grad der Entzündungsreaktion, der Zellschädigung und der durch CNTs verursachten Toxizität (Freisetzung von LDH). Die mit SEM aufgenommenen Bilder demonstrierten Nanoröhrenagglomerate und morphologische Veränderungen nach zellulärer Inkubation mit SWCNT, DWCNT und MWCNTs. Unsere Daten verdeutlichen den zugrunde liegenden Mechanismus mit der durch TitandioxidNanopartikel verursachten Verschlechterung von Atemwegserkrankungen. Dies deutet auf wichtige Auswirkungen auf die Umwelt- und Arbeitsschutzpolitik bei Exposition mit Nanomaterialien

Allergic airway inflammation induces upregulation of the expression of IL-23R by macrophages and not in CD3 + T cells and CD11c+F4/80- dendritic cells of the lung

Interleukin 23 and the interleukin 23 receptor (IL-23-IL23R) are described as the major enhancing factors for Interleukin 17 (IL-17) in allergic airway infammation. IL-17 is considered to induce neutrophilic infammation in the lung, which is often observed in severe, steroid-resistant asthma-phenotypes. For that reason, understanding of IL-23 and IL-17 axis is very important for future therapy strategies, targeting neutrophil pathway of bronchial asthma. This study aimed to investigate the distribution and expression of IL-23R under physiological and infammatory conditions. Therefore, a house dust mite (HDM) model of allergic airway infammation was performed by treating mice with HDM intranasally. Immunofuorescence staining with panel of antibodies was performed in lung tissues to examine the macrophage, dendritic cell, and T cell subpopulations. The allergic airway infammation was quantifed by histopathological analysis, ELISA measurements, and airway function. HDM-treated mice exhibited a signifcant allergic airway infammation including higher amounts of NE+ cells in lung parenchyma. We found only a small amount of IL-23R positives, out of total CD3+T cells, and no upregulation in HDMtreated animals. In contrast, the populations of F4/80+ macrophages and CD11c+F4/80− dendritic cells (DCs) with IL-23R expression were found to be higher. But HDM treatment leads to a signifcant increase of IL-23R+ macrophages, only. IL23R was expressed by every examined macrophage subpopulation, whereas only Mϕ1 and hybrids between Mϕ1 and Mϕ2 phenotype and not Mϕ2 were found to upregulate IL-23R. Co-localization of IL-23R and IL-17 was only observed in F4/80+ macrophages, suggesting F4/80+ macrophages express IL-23R along with IL-17 in lung tissue. The study revealed that macrophages involving the IL-23 and IL-17 pathway may provide a potential interesting therapeutic target in neutrophilic bronchial asthma

High-dose intranasal application of titanium dioxide nanoparticles induces the systemic uptakes and allergic airway inflammation in asthmatic mice

Background Titanium dioxide nanoparticles (TiO2 NPs) have a wide range of applications in several industrial and biomedical domains. Based on the evidence, the workers exposed to inhaled nanosized TiO2 powder are more susceptible to the risks of developing respiratory diseases. Accordingly, this issue has increasingly attracted the researchers’ interest in understanding the consequences of TiO2 NPs exposure. Regarding this, the present study was conducted to analyze the local effects of TiO2 NPs on allergic airway inflammation and their uptake in a mouse model of ovalbumin (OVA)-induced allergic airway inflammation. Methods For the purpose of the study, female BALB/c mice with or without asthma were intranasally administered with TiO2 NPs. The mice were subjected to histological assessment, lung function testing, scanning electron microscopy (SEM), inductively coupled plasma mass spectrometry (ICP-MS), and NP uptake measurement. In addition, T helper (Th) 1/Th2 cytokines were evaluated in the lung homogenate using the enzyme-linked immunosorbent assay. Results According to the results, the mice receiving OVA alone or OVA plus TiO2 NPs showed eosinophilic infiltrates and mucus overproduction in the lung tissues, compared to the controls. Furthermore, a significant elevation was observed in the circulating Th2 cytokines, including interleukin (IL)-4, IL-5, and IL-13 after NP exposure. The TiO2 NPs were taken up by alveolar macrophages at different time points. As the results of the SEM and ICP-MS indicated, TiO2 NPs were present in most of the organs in both asthmatic and non-asthmatic mice. Conclusion Based on the findings of the current study, intranasally or inhalation exposure to high-dose nanosized TiO2 particles appears to exacerbate the allergic airway inflammation and lead to systemic uptake in extrapulmonary organs. These results indicate the very important need to investigate the upper limit of intranasally or inhalation exposure to nanosized TiO2 particles in occupational and environmental health policy

High-dose intranasal application of titanium dioxide nanoparticles induces the systemic uptakes and allergic airway inflammation in asthmatic mice

BACKGROUND: Titanium dioxide nanoparticles (TiO2 NPs) have a wide range of applications in several industrial and biomedical domains. Based on the evidence, the workers exposed to inhaled nanosized TiO2 powder are more susceptible to the risks of developing respiratory diseases. Accordingly, this issue has increasingly attracted the researchers’ interest in understanding the consequences of TiO2 NPs exposure. Regarding this, the present study was conducted to analyze the local effects of TiO2 NPs on allergic airway inflammation and their uptake in a mouse model of ovalbumin (OVA)-induced allergic airway inflammation. METHODS: For the purpose of the study, female BALB/c mice with or without asthma were intranasally administered with TiO2 NPs. The mice were subjected to histological assessment, lung function testing, scanning electron microscopy (SEM), inductively coupled plasma mass spectrometry (ICP-MS), and NP uptake measurement. In addition, T helper (Th) 1/Th2 cytokines were evaluated in the lung homogenate using the enzyme-linked immunosorbent assay. RESULTS: According to the results, the mice receiving OVA alone or OVA plus TiO2 NPs showed eosinophilic infiltrates and mucus overproduction in the lung tissues, compared to the controls. Furthermore, a significant elevation was observed in the circulating Th2 cytokines, including interleukin (IL)-4, IL-5, and IL-13 after NP exposure. The TiO2 NPs were taken up by alveolar macrophages at different time points. As the results of the SEM and ICP-MS indicated, TiO2 NPs were present in most of the organs in both asthmatic and non-asthmatic mice. CONCLUSION: Based on the findings of the current study, intranasally or inhalation exposure to high-dose nanosized TiO2 particles appears to exacerbate the allergic airway inflammation and lead to systemic uptake in extrapulmonary organs. These results indicate the very important need to investigate the upper limit of intranasally or inhalation exposure to nanosized TiO2 particles in occupational and environmental health policy