iTRAQ-based identification of differentially expressed proteins in ED rat model induced by cold stress combined with...

We aim to identify serum biomarkers and key proteins of erectile dysfunction (ED) induced by cold stress combined with environmental oestrogen through iTRAQ combined with LC-MS/MS. ED rat model was established by using oestrogen-like feed and cold stimulation. Differentially expressed proteins in serum were screened and analysed with iTRAQ combined with LC-MS/MS and IPA bioanalysis platform. We found that 35 proteins were differentially expressed in the ED group, including 31 upregulated and four downregulated proteins. The molecular functions of differential proteins mainly involved the activation of endopeptidase inhibitor and regulator. The main pathways involved were the FXR/RXR activation signalling pathway and the acute phase response signalling pathway. Furthermore, three protein markers related to ED were obtained, namely C-reactive protein (CRP), T-kininogen 1 and apolipoprotein Protein H (APOH). ELISA results showed that compared with the control group, proteins of HPX, TTR, APOH, RBP4, CRP and ORM1 were significantly upregulated, but ANGPT1 protein was significantly downregulated in the serum of the ED group (p < 0.05). Conclusively, the candidate serum markers for ED induced by cold stress combined with environmental hormones were obtained. Our results indicate that inflammation and vascular endothelial function changes may play a key role in the occurrence and development of ED.