Effects of Ochratoxin a on Cytotoxicity and Cell Differentiation in Cultured Rat Embryonic Cells

Abstract

In the present study, the effects of ochratoxin A (OTA) on cytotoxicity, cell differentiation, and other cell functions in the embryonic midbrain cells, which are dopaminergic, were compared to those in the limb bud cells, which are nondopaminergic, to assess the selectivity of OTA central action. Twelve-day rat embryo midbrain and limb bud cells were cultured in Dulbecco's modified Eagle's medium nutrient and Ham's F12 (1:1) mix ture containing 10% Nuserum for 96 h in the presence of various concentrations of OTA. OTA signicfiantly reduced the levels of protein, DNA and glutathione, and [H]thymidine incorporation into DNA in both embryonic midbrain and limb bud cells in a similar concentration-dependent manner. The IC50 values for cytotoxicity measured by neutral red uptake were 1.10 microM in the midbrain cells and 1.05 microM in the limb bud cells. The IC50 values of cell differentiation were 1.10 microM in the midbrain cells and 1.0 microM in the limb bud cells. The addition of exogenous glutathione (32.5 microM) did not change the OTA-induced fall in protein and DNA levels, or the IC50 values of cytotoxicity and differentiation in the midbrain and limb bud cells. Data show that OTA does not appear to exert a selective toxic dopaminergic cell action and that OTA-induced cytotoxicity and inhibition of cell differentiation were not prevented by exogenous glutathione.

Neuronal models for evaluation of proliferation in vitro using high content screening☆

“…There are a number of proposed mechanisms for ochratoxin-A toxicity, including disruption of calcium and intracellular signaling, inhibition of mitochondrial respiration, and oxidative DNA damage (Ringot et al, 2006;Sava et al, 2006). In vitro, several studies have demonstrated ochratoxin-A can inhibit proliferation in human and rodent neural progenitor cells (Sava et al, 2007;Breier et al, 2008) and primary cultures of rat embryonic midbrain (Hong et al, 2000). To our knowledge, effects on proliferation in neuronal cell lines have not been reported previously, and none of the cell lines used in the present study detected ochratoxin-A.…”

Neurotoxic effects of ochratoxin A on the subventricular zone of adult mouse brain

“…Accordingly, in vitro studies have evaluated OTA in fetal midbrain cell cultures (Zhang et al, 2009), midbrain micromass cultures (Wilk-Zasadna & Minta, 2009) and adult hippocampal neural stem/progenitor cells (Sava et al, 2007). All these works concur showing an impact in decreasing cell viability and inhibiting proliferation and differentiation processes in a concentration-dependent manner (Ceccatelli et al, 2006;Hong et al, 2000;Sava et al, 2007;c Wilk-Zasadna & Minta, 2009;Zurich et al, 2005;Zurich & Honegger, 2011). OTA has also been reported to induce apoptosis in primary neurons (cortical neural cells) (Wilk-Zasadna & Minta, 2009;Zhang et al, 2009).…”

Ochratoxin A: The Continuing Enigma

“…They suggested this to be a result of poor dendritic growth in the developing brain. Support for this was provided by Hong et al,195 who demonstrated OTA to reduce neurite outgrowth in cultured 51 rat embryonic midbrain cells with IC 50 values of approximately 1.1 µM.…”

“…198 A study carried out by Hong and coworkers attempted to address some of these issues. 195 The authors assessed OTA-mediated cytotoxicity and cell differentiation in cultured rat embryonic midbrain (dopaminergic) and limb bud cells (nondopaminergic). OTA was observed to reduce [ 3 H]thymidine incorporation, cellular protein content, cell viability, and glutathione levels in both cell types, with midbrain cells being only minimally more sensitive.…”