Induction of apoptosis in the gonads of Mytilus edulis by metformin and increased temperature, via regulation of HSP70, CASP8, BCL2 and FAS

Pharmaceutically active compounds have been considered contaminants of emerging concern, in response to evidence that these substances may adversely affect aquatic organisms. Here we expose mussels for 7 days to metformin, the most commonly prescribed anti-diabetes treatment, at a concentration of 40 mu g/L and a high temperature of 20 degrees C. The apoptosis-related genes HSP70, CASP8, BCL2 and FAS showed variation in expression in gonadal tissue. The results suggest that complex interactions between these genes are modulating the onset of apoptotic changes such as atresia and follicle degeneration. The temperature induced apoptosis may be initiated by overexpression of CASP8. Conversely, metformin may induce apoptosis by suppressing the anti-apoptotic gene BCL2, thus promoting the process. Interestingly, apoptosis and follicle degeneration are likely FAS-mediated, following the synergistic effect of metformin and temperature. The potential of metformin to act as a non-traditional EDC, due to its impact on the reproductive system in mussels is discussed.

Automated summary

The study exposed mussels to metformin at a concentration of 40 mu g/L and a temperature of 20 degrees C for 7 days, showing variation in expression of apoptosis-related genes in gonadal tissue. The results suggest that metformin and temperature may initiate apoptosis through different mechanisms, modulating the onset of apoptotic changes in mussels.