In vivo assessment of molybdenum and cadmium co-induce nephrotoxicity via causing calcium homeostasis disorder and autophagy in ducks (Anas platyrhyncha)

Excess molybdenum (Mo) and cadmium (Cd) are widespread environmental and industrial metal pollutants. To evaluate the combined effects of Mo and Cd on calcium homeostasis and autophagy in duck kidneys. 160 healthy 7-day-old ducks (Anas platyrhyncha) were randomized into 4 groups and given to a basic diet, adding various doses of Mo or/and Cd for 16 weeks. On the 4th, 8th, 12th and 16th weeks, kidney tissues were collected. The study exhibited that Mo or/and Cd caused histological abnormality, reduced the activities of Ca2+ ATPase, Mg2+ ATPase, Na+-K+ ATPase and Ca2+-Mg2+ ATPase, K and Mg contents, and increased Na and Ca contents, upregulated CaMKKβ, CaMKIIɑ, CaN, IP3R, GRP78, GRP94, CRT mRNA levels and CaMKIIɑ, CaN, IP3R protein levels. Moreover, exposure to Mo or/and Cd notably promoted the amount of autophagosomes and LC3II immunofluorescence, upregulated AMPKα1, ATG5, Beclin-1, LC3A, LC3B mRNA levels and Beclin-1, LC3II/LC3I protein levels, downregulated mTOR, Dynein, P62 mRNA levels and P62 protein level. The changes of above indicators in combined group were more obvious. Overall, the results suggest that Mo and Cd co-exposure may can synergistically induce nephrotoxicity via causing calcium homeostasis disorder and autophagy in ducks.