In last decades, exposure to nanoparticles significantly increased, which can have negative impact on our health. Nanoparticles can also enter and accumulate in the brain, where they can cause toxicity through different mechanisms, including indirect toxicity through changes in cell-cell communication and secretion of different toxic mediators. In this conference contribution we presented the results of analysis of nanoparticle toxicity on mouse microglia and differentiated mouse neuronal cell cultures. We showed that the selected nanoparticles (maghemite (MGH), industrial TiO2 P25 and biomedical polyacrylic acid coated cobalt ferrite nanoparticles (PAA)) do not cause direct toxicity on either cell type, but can change secretion of signaling mediators in microglia cells, which are also the main phagocytic cells in the brain. The presence of nanoparticles minimally increased the secretion of TNF? and IL6 cytokines in microglia cells, but TiO2 P25 and MGH nanoparticles induced a concentration dependent increase in ROS. Induction of ROS is important toxicity mechanism, since neurons are highly susceptible to ROS due to their high energy metabolism and high lipid content.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 12473428Industrial nanoparticles (NPs) have become an important part of our everyday life, either through environmental pollution or through several different consumer products containing NPs. Such NPs can enter the brain, and although usually in really small quantities due to several efficient tissue barriers, etiological studies have linked environmental pollution with several negative consequences on human health, including increased incidence in developmental and neurodegenerative diseases in recent decades. In this conference contribution we presented the analysis of toxicity mechanisms of different industrial NPs (PAA, TiO2 P25, TiO2 21 nm, TiO2 FG, silver NPs, SiO2 NPs) on differentiated and non-differentiated SH-SY5Y human neuronal cells in vitro. We showed that NPs can induce cell toxicity through different mechanisms depending on their physico-chemical properties and stability in physiological media. In this contribution we presented for the first time the optimized protocol for neuronal cell differentiation and the results of longer NP exposure (5 days) in differentiated SH-SY5Y cells. By comparing non-differentiated and differentiated cells we also showed that the same NP concentrations have less effect on viability of differentiated cells (most probably due to the absence of cell division), but are more susceptible to ROS compared to non-differentiated cells. ROS levels were similar following 24 h or 5-day incubation, indicating that neuronal cells do not effectively respond to oxidative stress with an antioxidant response to restore homeostasis. With this contribution we emphasized the importance of toxicity analysis on more relevant, differentiated neural cell models, since their susceptibility to certain toxicity mechanisms can be significantly different compared to non-differentiated cells. The contribution was also presented on COST action BIONECA meeting in Skopje, Macedonia.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 12473172During the project, the previously and newly acquired methodological knowledge and expertise was transferred to younger colleagues, students and researchers from collaborating groups. The project leader introduced into laboratory work and trained several younger colleagues and master degree students, she shared her knowledge and lead their research work for their master theses. With two master theses, this included establishment of novel neural cell differentiation protocols. The candidates acquired important knowledge and expertise that now helps them in their research work. One research project for the master thesis was carried out in close collaboration with Laboratory for Biotechnology, Institute of Chemistry Ljubljana, which also enabled easier transfer of knowledge. During this postdoctoral project, the experimental work for three master theses was performed, one thesis was already defended [COBISS ID 4503665] and two are in preparation with all experimental fork finished.
D.11 Other
COBISS.SI-ID: 4503665During the postdoctoral project, two protocols for differentiation of neural cell lines were developed and optimized (for human neural cell line SH-SY5Y and immortalized mouse neuronal cells CAD), which enabled us to analyze toxicity of nanoparticles on for in vivo more relevant in vitro cell models. Since differentiated cultures were more stable and could be grown without sub-culturing for longer time periods, we could also analyze the toxicity mechanisms during long-term nanoparticle exposure. In vitro cell models for analysis of long-term exposure scenarios are important, since not many such models have been developed so far, and the properties of differentiated cells in vitro better resemble cells in vivo, thus giving more relevant results. Besides the two protocols for differentiation of neuronal cell lines we also obtained the protocols for culturing and differentiation of induced human pluripotent cells, which can be induced into embryonal neuronal cells and terminally differentiated into neurons. The knowledge was obtained during the exchange through the COST action BIONECA and was transferred to the home research group. All protocols and newly obtained knowledge will enable the research group to carry out relevant experiments of long-term toxicity for nanoparticles or other materials/drugs also in the future, and thus generate important results and knowledge on nanotoxicology and neurotoxicology.
F.04 Increase of the technological level