In vivo assessment of molybdenum and cadmium co-induced the mRNA levels of heat shock proteins, inflammatory cytokines and apoptosis in shaoxing duck (Anas platyrhyncha) testicles

Abstract

Cadmium (Cd) and high dietary intake of molybdenum (Mo) can lead to adverse reactions on animals, but the combined impacts of Mo and Cd on testicle are not clear. To investigate the co-induced toxic effects of Mo and Cd in duck testicles on the mRNA levels of heat shock proteins (HSPs), inflammatory cytokines, and apoptosis. A total of sixty 11-day-old male Shaoxing ducks (Anas platyrhyncha) were randomly divided into 6 groups and testicles were collected on day 120. The mRNA levels of HSPs (HSP60, HSP70, HSP90), inflammatory cytokines (TNF-α, NF-κB, COX-2), and apoptosis genes (Bcl-2, Bak-1, Caspase-3) were determined by real-time quantitative polymerase chain reaction (RT-qPCR), meanwhile the changes of ultrastructural were evaluated. The results showed HSPs mRNA levels were increased in high Mo and Cd groups, however, they were decreased in high dose Mo and Cd co-treated group. In all treatment groups, the mRNA levels of Bak-1 and Caspase-3 were upregulated, and Bcl-2 mRNA level was downregulated, especially in combination groups. The TNF-α, NF-κB, and COX-2 expression in co-exposure groups were higher than those in single groups. Furthermore, the ultrastructural changes showed nuclear deformation, mitochondria hyperplasia and cristaes rupture, and vacuolation in combination groups. Changes of all above factors indicated a possible synergistic relationship between the two elements, and the high expression of HSPs and inflammatory cytokines may play a role in the resistance of testicles toxicity induced by Mo or Cd or both.