Mitochondrial gene expression, antioxidant responses, and histopathology after cadmium exposure.
The present study investigates cadmium effects on the transcription of mitochondrial genes of Procambarus clarkii after acute (0.05, 0.5, and 5 mg Cd/L; 4-10 days) and chronic exposures (10 μg Cd/L; 30-60 days). Transcriptional responses of cox1, atp6, and 12S using quantitative real-time RT-PCR were assessed in gills and hepatopancreas. Additionally, the expression levels of genes involved in detoxification and/or oxidative stress responses [mt, sod(Mn)] and enzymatic activities of antioxidants (SOD, CAT, GPX, and GST) were analyzed. The histopathological effects in hepatopancreas of crayfish were evaluated by light microscopy. Relationships between endpoints at different levels of biological organization and Cd bioaccumulation were also examined. Cd induced high levels of bioaccumulation, which was followed by mitochondrial dysfunction and histological alterations in both experiments. Moreover, perturbations in the defence mechanisms against oxidative stress tended to increase with time. Results also showed that molecular responses can vary depending on the intensity and duration of the chemical stress applied to the organisms and that the study of mt gene expression levels seemed to be the best tool to assess Cd intoxication.
Laboratory of Radioecology and Ecotoxicology (LRE), Institute of Radioprotection and Nuclear Safety (IRSN), Bd 186, BP 3, 13115 Saint-Paul-Lez-Durance, France; Laboratory of Aquatic Ecotoxicology (EA), University of Bordeaux1/UMR CNRS 5805, Dr Peyneau Square, 33120 Arcachon, France.
Simone
S
Al Kaddissi
Alexia
A
Legeay
Antonia Concetta
AC
Elia
Patrice
P
Gonzalez
Magali
M
Floriani
Isabelle
I
Cavalie
Jean-Charles
JC
Massabuau
Rodolphe
R
Gilbin
Olivier
O
Simon
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D003400:Astacoidea / Q000187:drug effects*; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D015870:Gene Expression; D050259:Genes, Mitochondrial; D005880:Gills / Q000187:drug effects / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D043143:Hepatopancreas / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000378:metabolism; D014158:Transcription, Genetic; D014873:Water Pollutants / Q000378:metabolism / Q000633:toxicity*
D000975:Antioxidants; D014873:Water Pollutants; D002104:Cadmium; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase