Kristina Attoff

PhD student

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Works at Department of Biochemistry and Biophysics
Telephone 08-16 42 64
Visiting address Svante Arrhenius väg 16
Room M 412
Postal address Institutionen för biokemi och biofysik 106 91 Stockholm


Research group: Anna Forsby


A selection from Stockholm University publication database
  • 2016. Kristina Attoff (et al.). Toxicology in Vitro 35, 100-111

    Acrylamide is a well-known neurotoxic compound and people get exposed to the compound by food consumption and environmental pollutants. Since acrylamide crosses the placenta barrier, the fetus is also being exposed resulting in a risk for developmental neurotoxicity. In this study, the neural progenitor cell line C17.2 and the neuroblastoma cell line SH-SY5Y were used to study proliferation and differentiation as alerting indicators for developmental neurotoxicity. For both cell lines, acrylamide reduced the number of viable cells by reducing proliferation and inducing cell death in undifferentiated cells. Acrylamide concentrations starting at 10 fM attenuated the differentiation process in SH-SY5Y cells by sustaining cell proliferation and neurite outgrowth was reduced at concentrations from 10 pM. Acrylamide significantly reduced the number of neurons starting at 1 mu M and altered the ratio between the different phenotypes in differentiating C17.2 cell cultures. Ten micromolar of acrylamide also reduced the expression of the neuronal and astrocyte biomarkers. Although the neurotoxic concentrations in the femtomolar range seem to be specific for the SH-SY5Y cell line, the fact that micromolar concentrations of acrylamide seem to attenuate the differentiation process in both cell lines raises the interest to further investigations on the possible developmental neurotoxicity of acrylamide.

  • 2016. Kristina Attoff, Anna Forsby, Ann-Kristin Östlund Farrants.

    The number of children with neurodevelopmental disorders is increasing worldwide which makes it a public concern. Exposure to environmental chemicals has been reported as a source of developmental neurotoxicity. There is also an increase in the number of chemicals reaching the global market each year and currently there are thousands of substances that have not yet been tested for developmental neurotoxicity. The current developmental neurotoxicity testing guidelines are time consuming, expensive, require a lot of animals and have relatively low sensitivity understanding for the mechanisms of toxicology. The field of developmental neurotoxicity testing is in need of a paradigm shift to the use of alternative in vitro methods capable of testing and screening large number of substances. The next generation developmental neurotoxicity testing will consist of both in silico and in vitro testing that has to be used in a combined fashion so that it will generate a more rapid and efficient toxicity testing. The methods need to be standardized between laboratories so that reproducible data can be obtained. Simple endpoints will simply not be enough for in vitro developmental neurotoxicity testing models. Rather, a battery of more refined endpoints that pinpoints the specific toxicity of a compound, discriminate between different neural subpopulations and different stages of neural differentiation is crucial for success. The use of mRNA biomarkers could be a good example of such an endpoint, and have been suggested to be valuable in detecting developmental neurotoxicity. This thesis will give a broad overview of different alternative in vitro models for developmental neurotoxicity. Developmental neurotoxicity of acrylamide was investigated by using selected cell models and endpoints. Acrylamide is a well-known neurotoxic compound and most people get exposed to the compound by food consumption and from environmental pollutants. Since acrylamide crosses the placenta barrier, the fetus is also being exposed and the risk for adverse effects in the developing nervous system is overwhelming. The neural progenitor cell line C17.2 and the neuroblastoma cell line SH-SY5Y were used to study proliferation and differentiation as indicators for developmental neurotoxicity. The reduced neurite outgrowth in the SH-SY5Y cell model occurred at up to seven orders of magnitude lower than what have been previously shown for different neural cell systems. Acrylamide also affected the differentiation process in both neurons and glia cells in the C17.2 cell line. We show that acrylamide attenuated neural differentiation at seven orders of magnitude lower concentrations than the estimated plasma concentration of free acrylamide in the fetus. The fact that low concentrations seem to delay the differentiation process in both cell lines, raises cause for an alarm for developmental neurotoxicity induced by acrylamide.  

  • 2017. Jessica Lundqvist (et al.). Applied In Vitro Toxicology

    Using general cytotoxicity assays in combination with in vitro tests for organ-specific toxicity has been proposed as an alternative approach to animal tests for estimation of acute systemic toxicity. Here, we present the C17.2 neural progenitor cell line as an option for estimation of acute neurotoxicity. The C17.2 cells were differentiated for 6 days in serum-free N2 medium with brain-derived neurotrophic factor and nerve growth factor to a mixed culture of neurons and astrocytes. The cells were then exposed to noncytotoxic concentrations of acetylsalicylic acid, atropine, digoxin, ethanol, nicotine, or strychnine for 48 hours and the mRNA levels of glial fibrillary acidic protein, βIII-tubulin, and heat shock protein 32 were analyzed as biomarkers for astrocytes, neurons, and cellular stress respectively. As a functional endpoint, the cell membrane potential (CMP) was monitored after acute addition of each compound to the differentiated C17.2 cells, by using the fluorescent FLIPR® membrane potential assay. Nicotine [3.2E-04 M], atropine [1.2E-05 M], or strychnine [6.4E-05 M] resulted in altered gene expression of at least one biomarker for each compound, indicating alerts for neurotoxicity. The three compounds also induced depolarization of the CMP at the lowest observed effect concentrations 9.5E-05 M of nicotine, 1.5E-05 M of atropine, and 6.9E-07 M of strychnine. The non-neurotoxic compounds acetylsalicylic acid, ethanol, and digoxin did neither affect the mRNA levels, nor the CMP. This study showed that the differentiated C17.2 cells might be useful for estimation of acute neurotoxicity by analyzing expression of mRNA biomarkers and CMP alterations.

  • 2017. Kristina Attoff (et al.). PLoS ONE 12 (12)

    Despite its high relevance, developmental neurotoxicity (DNT) is one of the least studied forms of toxicity. Current guidelines for DNT testing are based on in vivo testing and they require extensive resources. Transcriptomic approaches using relevant in vitro models have been suggested as a useful tool for identifying possible DNT-generating compounds. In this study, we performed whole genome microarray analysis on the murine progenitor cell line C17.2 following 5 and 10 days of differentiation. We identified 30 genes that are strongly associated with neural differentiation. The C17.2 cell line can be differentiated into a co-culture of both neurons and neuroglial cells, giving a more relevant picture of the brain than using neuronal cells alone. Among the most highly upregulated genes were genes involved in neurogenesis (CHRDL1), axonal guidance (BMP4), neuronal connectivity (PLXDC2), axonogenesis (RTN4R) and astrocyte differentiation (S100B). The 30 biomarkers were further validated by exposure to non-cytotoxic concentrations of two DNT-inducing compounds (valproic acid and methylmercury) and one neurotoxic chemical possessing a possible DNT activity (acrylamide). Twenty-eight of the 30 biomarkers were altered by at least one of the neurotoxic substances, proving the importance of these biomarkers during differentiation. These results suggest that gene expression profiling using a predefined set of biomarkers could be used as a sensitive tool for initial DNT screening of chemicals. Using a predefined set of mRNA biomarkers, instead of the whole genome, makes this model affordable and high-throughput. The use of such models could help speed up the initial screening of substances, possibly indicating alerts that need to be further studied in more sophisticated models.

Show all publications by Kristina Attoff at Stockholm University

Last updated: August 29, 2019

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