High PPC impairs female reproduction by inhibiting the 20E-Vg/VgR pathway.

Hyperproteinemia is characterized by an unusually high plasma protein concentration (PPC). It affects both humans and animals. In this study, we used a silkworm model of hyperproteinemia to explore the mechanisms by which high PPC impairs female reproduction. Analysis of ovarian transcriptomes and qRT-PCR revealed that high PPC reduced the expression of vitellogenin (Vg) in the fat body and vitellogenin receptor (VgR) in the ovary. Further biochemical and gene expression analyses showed that high PPC decreased the titer of 20-hydroxyecdysone (20E) and the expression of key genes in the 20E-Vg/VgR signaling pathway. Exogenous 20E supplementation restored the expression of pathway components and effectively rescued female reproductive function. These findings offer new evidence for how high PPC affects female reproduction and provide a useful reference for future clinical research.