BACKGROUND: Inhalation of lead oxide nanoparticles (PbO NPs), which are emitted to the environment by high-temperature technological processes, heavily impairs target organs. These nanoparticles pass through the lung barrier and are distributed via the blood into secondary target organs, where they cause numerous pathological alterations. Here, we studied in detail, macrophages as specialized cells involved in the innate and adaptive immune response in selected target organs to unravel their potential involvement in reaction to subchronic PbO NP inhalation. In this context, we also tackled possible alterations in lipid uptake in the lungs and liver, which is usually associated with foam macrophage formation. RESULTS: The histopathological analysis of PbO NP exposed lung revealed serious chronic inflammation of lung tissues. The number of total and foam macrophages was significantly increased in lung, and they contained numerous cholesterol crystals. PbO NP inhalation induced changes in expression of phospholipases C (PLC) as enzymes linked to macrophage-mediated inflammation in lungs. In the liver, the subchronic inhalation of PbO NPs caused predominantly hyperemia, microsteatosis or remodeling of the liver parenchyma, and the number of liver macrophages also significantly was increased. The gene and protein expression of a cholesterol transporter CD36, which is associated with lipid metabolism, was altered in the liver. The amount of selected cholesteryl esters (CE 16:0, CE 18:1, CE 20:4, CE 22:6) in liver tissue was decreased after subchronic PbO NP inhalation, while total and free cholesterol in liver tissue was slightly increased. Gene and protein expression of phospholipase PLCβ1 and receptor CD36 in human hepatocytes were affected also in in vitro experiments after acute PbO NP exposure. No microscopic or serious functional kidney alterations were detected after subchronic PbO NP exposure and CD68 positive cells were present in the physiological mode in its interstitial tissues. CONCLUSION: Our study revealed the association of increased cholesterol and lipid storage in targeted tissues with the alteration of scavenger receptors and phospholipases C after subchronic inhalation of PbO NPs and yet uncovered processes, which can contribute to steatosis in liver after metal nanoparticles exposure.

• Klíčová slova
• Cholesterol metabolism, Inhalation, Lead oxide nanoparticles, Liver macrophages, Lung macrophages,
• MeSH
• cholesterol MeSH
• fosfolipasy typu C * MeSH
• kovové nanočástice * chemie   MeSH
• lidé MeSH
• makrofágy MeSH
• olovo MeSH
• oxidy MeSH
• zánět MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cholesterol MeSH
• fosfolipasy typu C * MeSH
• lead oxide MeSH Prohlížeč
• olovo MeSH
• oxidy MeSH

The inhalation of metal (including lead) nanoparticles poses a real health issue to people and animals living in polluted and/or industrial areas. In this study, we exposed mice to lead(II) nitrate nanoparticles [Pb(NO3)2 NPs], which represent a highly soluble form of lead, by inhalation. We aimed to uncover the effects of their exposure on individual target organs and to reveal potential variability in the lead clearance. We examined (i) lead biodistribution in target organs using laser ablation and inductively coupled plasma mass spectrometry (LA-ICP-MS) and atomic absorption spectrometry (AAS), (ii) lead effect on histopathological changes and immune cells response in secondary target organs and (iii) the clearance ability of target organs. In the lungs and liver, Pb(NO3)2 NP inhalation induced serious structural changes and their damage was present even after a 5-week clearance period despite the lead having been almost completely eliminated from the tissues. The numbers of macrophages significantly decreased after 11-week Pb(NO3)2 NP inhalation; conversely, abundance of alpha-smooth muscle actin (α-SMA)-positive cells, which are responsible for augmented collagen production, increased in both tissues. Moreover, the expression of nuclear factor κB (NF-κB) and selected cytokines, such as tumor necrosis factor alpha (TNFα), transforming growth factor beta 1 (TGFβ1), interleukin 6(IL-6), IL-1α and IL-1β , displayed a tissue-specific response to lead exposure. In summary, diminished inflammatory response in tissues after Pb(NO3)2 NPs inhalation was associated with prolonged negative effect of lead on tissues, as demonstrated by sustained pathological changes in target organs, even after long clearance period.

• Klíčová slova
• LA-ICP-MS imaging, clearance, inhalation, lead nanoparticles, toxicity,
• MeSH
• aktiny agonisté   genetika   imunologie   MeSH
• alveolární makrofágy účinky léků   imunologie   patologie   MeSH
• aplikace inhalační MeSH
• biologická dostupnost MeSH
• dusičnany farmakokinetika   toxicita   MeSH
• exprese genu MeSH
• inhalační expozice analýza   MeSH
• interleukin-1alfa agonisté   genetika   imunologie   MeSH
• interleukin-1beta agonisté   genetika   imunologie   MeSH
• interleukin-6 agonisté   genetika   imunologie   MeSH
• játra účinky léků   imunologie   patologie   MeSH
• kovové nanočástice aplikace a dávkování   toxicita   MeSH
• látky znečišťující vzduch farmakokinetika   toxicita   MeSH
• myši inbrední ICR MeSH
• myši MeSH
• NF-kappa B agonisté   genetika   imunologie   MeSH
• olovo farmakokinetika   toxicita   MeSH
• plíce účinky léků   imunologie   patologie   MeSH
• poločas MeSH
• spektrofotometrie atomová MeSH
• tkáňová distribuce MeSH
• TNF-alfa agonisté   genetika   imunologie   MeSH
• transformující růstový faktor beta1 agonisté   genetika   imunologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aktiny MeSH
• alpha-smooth muscle actin, mouse MeSH Prohlížeč
• dusičnany MeSH
• Il1a protein, mouse MeSH Prohlížeč
• IL1B protein, mouse MeSH Prohlížeč
• interleukin-1alfa MeSH
• interleukin-1beta MeSH
• interleukin-6, mouse MeSH Prohlížeč
• interleukin-6 MeSH
• látky znečišťující vzduch MeSH
• lead nitrate MeSH Prohlížeč
• NF-kappa B MeSH
• olovo MeSH
• Tgfb1 protein, mouse MeSH Prohlížeč
• TNF-alfa MeSH
• transformující růstový faktor beta1 MeSH