The potential of nanomaterials use is huge, especially in fields such as medicine or industry. Due to widespread use of nanomaterials, their cytotoxicity and involvement in cellular pathways ought to be evaluated in detail. Nanomaterials can induce the production of a number of substances in cells, including reactive oxygen species (ROS), participating in physiological and pathological cellular processes. These highly reactive substances include: superoxide, singlet oxygen, hydroxyl radical, and hydrogen peroxide. For overall assessment, there are a number of fluorescent probes in particular that are very specific and selective for given ROS. In addition, due to the involvement of ROS in a number of cellular signaling pathways, understanding the principle of ROS production induced by nanomaterials is very important. For defense, the cells have a number of reparative and especially antioxidant mechanisms. One of the most potent antioxidants is a tripeptide glutathione. Thus, the glutathione depletion can be a characteristic manifestation of harmful effects caused by the prooxidative-acting of nanomaterials in cells. For these reasons, here we would like to provide a review on the current knowledge of ROS-mediated cellular nanotoxicity manifesting as glutathione depletion, including an overview of approaches for the detection of ROS levels in cells.

• Klíčová slova
• cell injury, fluorescence probes, glutathione, nanotoxicity, oxidative stress, reactive oxygen species,
• MeSH
• buňky účinky léků   metabolismus   MeSH
• glutathion metabolismus   MeSH
• lidé MeSH
• nanostruktury toxicita   MeSH
• oxidační stres účinky léků   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• glutathion MeSH
• reaktivní formy kyslíku MeSH

Hypoxia is involved in the regulation of stem cell fate, and hypoxia-inducible factor 1 (HIF-1) is the master regulator of hypoxic response. Here, we focus on the effect of hypoxia on intracellular signaling pathways responsible for mouse embryonic stem (ES) cell maintenance. We employed wild-type and HIF-1α-deficient ES cells to investigate hypoxic response in the ERK, Akt, and STAT3 pathways. Cultivation in 1% O2 for 24 h resulted in the strong dephosphorylation of ERK and its upstream kinases and to a lesser extent of Akt in an HIF-1-independent manner, while STAT3 phosphorylation remained unaffected. Downregulation of ERK could not be mimicked either by pharmacologically induced hypoxia or by the overexpression. Dual-specificity phosphatases (DUSP) 1, 5, and 6 are hypoxia-sensitive MAPK-specific phosphatases involved in ERK downregulation, and protein phosphatase 2A (PP2A) regulates both ERK and Akt. However, combining multiple approaches, we revealed the limited significance of DUSPs and PP2A in the hypoxia-mediated attenuation of ERK signaling. Interestingly, we observed a decreased reactive oxygen species (ROS) level in hypoxia and a similar phosphorylation pattern for ERK when the cells were supplemented with glutathione. Therefore, we suggest a potential role for the ROS-dependent attenuation of ERK signaling in hypoxia, without the involvement of HIF-1.

• MeSH
• down regulace MeSH
• faktor 1 indukovatelný hypoxií - podjednotka alfa metabolismus   MeSH
• mitogenem aktivované proteinkinasy kinas metabolismus   MeSH
• myší embryonální kmenové buňky metabolismus   MeSH
• myši MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• faktor 1 indukovatelný hypoxií - podjednotka alfa MeSH
• mitogenem aktivované proteinkinasy kinas MeSH
• reaktivní formy kyslíku MeSH

Reactive oxygen species (ROS) are important regulators of cellular functions. In embryonic stem cells, ROS are suggested to influence differentiation status. Regulated ROS formation is catalyzed primarily by NADPH-dependent oxidases (NOXs). Apocynin and diphenyleneiodonium are frequently used inhibitors of NOXs; however, both exhibit uncharacterized effects not related to NOXs inhibition. Interestingly, in our model of mouse embryonic stem cells we demonstrate low expression of NOXs. Therefore we aimed to clarify potential side effects of these drugs. Both apocynin and diphenyleneiodonium impaired proliferation of cells. Surprisingly, we observed prooxidant activity of these drugs determined by hydroethidine. Further, we revealed that apocynin inhibits PI3K/Akt pathway with its downstream transcriptional factor Nanog. Opposite to this, apocynin augmented activity of canonical Wnt signaling. On the contrary, diphenyleneiodonium activated both PI3K/Akt and Erk signaling pathways without affecting Wnt. Our data indicates limits and possible unexpected interactions of NOXs inhibitors with intracellular signaling pathways.

• MeSH
• acetofenony farmakologie   MeSH
• extracelulárním signálem regulované MAP kinasy metabolismus   MeSH
• fosfatidylinositol-3-kinasy metabolismus   MeSH
• fosforylace účinky léků   MeSH
• myší embryonální kmenové buňky účinky léků   metabolismus   MeSH
• myši MeSH
• NADPH-oxidasy genetika   metabolismus   MeSH
• oniové sloučeniny farmakologie   MeSH
• oxidační stres účinky léků   MeSH
• proliferace buněk účinky léků   MeSH
• proteiny Wnt metabolismus   MeSH
• protoonkogenní proteiny c-akt metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• synergismus léků MeSH
• transkripční faktor STAT3 metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetofenony MeSH
• acetovanillone MeSH Prohlížeč
• diphenyleneiodonium MeSH Prohlížeč
• extracelulárním signálem regulované MAP kinasy MeSH
• fosfatidylinositol-3-kinasy MeSH
• NADPH-oxidasy MeSH
• oniové sloučeniny MeSH
• proteiny Wnt MeSH
• protoonkogenní proteiny c-akt MeSH
• reaktivní formy kyslíku MeSH
• transkripční faktor STAT3 MeSH