Article

Mycotoxin fumonisin B1 alters cellular redox balance and signalling pathways in rat liver and kidney.

Faculty of Pharmacy and Biochemistry, Department of Medical Biochemistry and Haematology, Domagojeva 2, 10000, Zagreb, Croatia.
Toxicology (impact factor: 3.68). 01/2008; 242(1-3):31-8. DOI:10.1016/j.tox.2007.09.006 pp.31-8
Source: PubMed

ABSTRACT Mycotoxin fumonisin B(1) (FB(1)) is a frequent contaminant of grain, particularly maize, but the mechanism of its toxicity in the kidney and liver is not fully understood. FB(1)-stimulated oxidative stress might disturb cellular redox state and signal transduction pathways of the target cells. In this study we measured total intracellular glutathione (GSH), and assessed mitogen-activated protein kinases (MAPKs) activation and the expression of heat shock proteins (Hsps) Hsp25 and Hsp70 in the liver and kidney of male Wistar rats given 0.5 mg FB(1)/kg b.w. intraperitoneally for 2 or 7 days. The effect of FB(1) on GSH levels, MAPK activation and Hsp expression was found to be related to the type of tissue affected and the length of treatment. In rat liver, cellular GSH content increased, Hsp expression was up-regulated, and ERK and p38 were activated after the 7-day treatment, while even the 2-day treatment sufficed to produce phospho-JNK signal. In rat kidney, GSH levels decreased after the 2- and 7-day treatment with FB(1), while after the 7-day treatment all three MAPKs were activated, Hsp25 expression increased and Hsp70 expression decreased. In conclusion, FB(1) alters cellular redox balance, which leads to tissue-specific activation and expression of redox-sensitive signalling molecules. It seems that kidney cells are more sensitive to adverse effects of FB(1).

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    Article: Changes in metallothionein level in rat hepatic tissue after administration of natural mouldy wheat.
    Anna Vasatkova, Sarka Krizova, Vojtech Adam, Ladislav Zeman, Rene Kizek
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    ABSTRACT: Mycotoxins are secondary metabolites produced by microfungi that are capable of causing disease and death in humans and other animals. This work was aimed at investigation of influence of mouldy wheat contaminated by pathogenic fungi producing mycotoxins on metallothionein levels in hepatic tissue of rats. The rats were administrating feed mixtures with different contents of vitamins or naturally mouldy wheat for 28 days. It was found that the wheat contained deoxynivalenol (80 +/- 5 microg per kg of mouldy wheat), zearalenone (56 +/- 3 microg/kg), T2-toxin (20 +/- 2 microg/kg) and aflatoxins as a sum of B1, B2, G1 and G2 (3.9 +/- 0.2 microg/kg). Rats were fed diets containing 0, 33, 66 and 100% naturally moulded wheat. Control group 0, 33, 66 and 100% contained vitamins according to Nutrient Requirements of Rats (NRC). Other four groups (control group with vitamins, vit33, vit66 and vit100%) were fed on the same levels of mouldy wheat, also vitamins at levels 100% higher than the previous mixtures. We determined weight, feed conversion and performed dissection to observe pathological processes. Changes between control group and experimental groups exposed to influence of mouldy wheat and experimental groups supplemented by higher concentration of vitamins and mouldy wheat were not observed. Livers were sampled and did not demonstrate significant changes in morphology compared to control either. In the following experiments the levels of metallothionein as a marker of oxidative stress was determined. We observed a quite surprising trend in metallothionein levels in animals supplemented with increased concentration of vitamins. Its level enhanced with increasing content of mouldy wheat. It was possible to determine a statistically significant decline (p<0.05) between control group and groups of animals fed with 33, 66 and 100% mouldy wheat. It is likely that some mycotoxins presented in mouldy wheat are able to block the mechanism of metallothionein synthesis.
    International Journal of Molecular Sciences 03/2009; 10(3):1138-60. · 2.60 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

2-day treatment sufficed
 
7 days
 
7-day treatment
 
adverse effects
 
cellular GSH content
 
cellular redox state
 
frequent contaminant
 
heat shock proteins
 
kidney cells
 
male Wistar rats
 
MAPK activation
 
mitogen-activated protein kinases
 
Mycotoxin fumonisin B(1)
 
rat kidney
 
redox-sensitive signalling molecules
 
signal transduction pathways
 
target cells
 
three MAPKs
 
tissue-specific activation
 
total intracellular glutathione