Lipopolysaccharide and heat stress impair the estradiol biosynthesis in granulosa cells via increase of HSP70 and inhibition of smad3 phosphorylation and nuclear translocation
LPS and heat stress induce downregulation of FSHR and CYP19A1 expressions in GCs via upregulation of HSP70. Inhibition of HSP70 activity can restore the FSHR and CYP19A1 expressions in GCs. Activation of HSP70 alone can mimic the effects of LPS and heat stress on GCs. HSP70 exert its inhibitory effects by indirect inhibition of Smad3 phosphorylation and nuclear translocation.