Cloning of PGC-1α from Grass Carp and Its Response to Cadmium-Induced Stress

摘要

Cadmium (Cd) is a demonstrated pollutant in the aquatic environment. The bioaccumulation of Cd in fish affects the mitochondrial viability such as free radicals generation and lipid peroxidation. Peroxisome proliferator-activated receptor (PPAR) γ co-activator α (PGC-1α) is crucial for mitochondrial biogenesis and metabolism. However, only a few PGC-1α s have been identified in fish, and their functions remain obscure. In the present study, PGC-1α gene was cloned from Ctenopharyngodon idellus (grass carp). Sequencing analysis revealed that grass carp PGC-1α also contained a PPARγ binding site, a RNA recognition motif and several serine-arginine repeats like other PGC-1α s, suggesting a similar function of PGC- 1α in grass carp compared with that in mammals. PGC-1α expression was mainly observed in tissues with high content of mitochondria such as kidney and red muscle, then heartbrain white muscle liver adipose. When the fish were exposed to cadmium for 24h, 5 μM cadmium promoted mitochondrial succinate dehydrogenase activity and PGC-1α expression enhancement. While 20 μM cadmium slightly raised the enzyme activity, which was consistent with PGC-1α expression increment. These results suggested that grass carp PGC-1α was involved in cadmium induced stress and it may be associated with mitochondrial function.