Abstract: Objective To screen the differentially expressed proteins in the kidneys of rats exposed to chronic intermittent hypoxia (CIH) based on TMT-PRM technology to identify the potential biomarkers of renal injuries induced by CIH. Methods Twenty SD rats were randomized into two groups (n=10) and exposed to CIH or normoxia. After 12 weeks of exposure, the kidneys of the rats were collected for observing pathological changes. The renal proteins were extracted, enzymatically digested and labelled with TMT, and LC-MS/MS was used to identify the proteins. The data were processed using Proteome Discoverer2.4 for bioinformatic analysis of the differentially expressed proteins. PRM technology was used to verify the expression of the candidate proteins. Results CIH induced obvious renal injury in the rats, manifested by irregular glomerulus and swelling of the epithelial cells of the renal tubules. A total of 31 differentially expressed proteins were identified in CIH rats, including 22 up-regulated and 9 down-regulated proteins. Enrichment analysis of GO function and KEGG pathway analysis showed that the differentially expressed proteins participated mainly in the biological processes of cell adhesion, hypoxic stress, and calcium ions and were involved in the PPAR, AMPK, and metabolic pathways. In PRM quantitative analysis, 3 proteins, namely P07379 (PCK1), P19132 (Fth1) and Q5XI79 (Ndufaf7), showed results consistent with those of TMT-quantitative proteomic analysis. Conclusion Thirty-one differentially expressed proteins were identified in the renal tissues of rats with CIH exposure, and among them P07379 (PCK1), P19132 (Fth1), and Q5XI79 (Ndufaf7) may be the key proteins closely related to the renal injury in induced by CIH.

Key words: chronic intermittent hypoxia; kidney; proteomes; TMT; PRM