Short-term cadmium exposure induces stress responses in frog (Pelophylax bergeri) skin organ culture

• Establishment of P. bergeri skin in organ culture as in vitro model.
• Short-term exposure of skin organ culture to Cd-induced stress responses.
• Cd exposure caused histo-pathological alterations in frog skin.
• Cd induced a dose- and time-dependent induction of both HSP70 and MT stress genes.
• P. bergeri skin organ culture is a potential tool for ecotoxicology studies.

There have been a few studies on the negative effects of pollutants on amphibian skin, the first structural barrier that interacts with the environment and its potential contaminants. In this study an ex vivo skin organ culture from the amphibian Pelophylax bergeri was used to evaluate cell stress responses induced by short-term exposure to cadmium (Cd), a toxic heavy metal known to be an environmental hazard to both humans and wildlife. Histopathological studies were carried out on skin explants using light microscopy and changes in the expression of stress proteins, such as Metallothionein (MT) and Heat shock proteins (HSPs), were investigated by Real-time RT-PCR. Results revealed that amphibian skin reacts to Cd-induced stress by activating biological responses such as morphological alterations and dose- and time-dependent induction of Mt and Hsp70 mRNA expression, suggesting their potential role as biomarkers of exposure to Cd. This work provides a basis for a better understanding of the tissue-specific responses of amphibian skin as a target organ to Cd exposure and its in vitro use for testing potentially harmful substances present in the environment.