Proteome analysis of altered proteins in streptozotocin-induced diabetic rat kidney using the fluorogenic derivatization-liquid chromatography-tandem mass spectrometry method

To find new molecular markers for early diagnosis of diabetic nephropathy, we applied fluorogenic derivatization-liquid chromatography-tandem mass spectrometry to identify the differentially expressed proteins in the kidney of control and streptozotocin-induced diabetic rats. The Sprague-Dawley rats were injected with the sodium citrate buffer or streptozotocin and then killed after 1, 4, 12 and 24 weeks. The results showed that seven proteins were significantly changed after 1 week of injection. Only one protein had significantly changed after 4 weeks of injection. However, after 12 weeks of injection, the number of altered proteins rose to 10. After 24 weeks of injection, 18 proteins had altered significantly. Five common proteins were significantly altered at week 12 and 24 after injection, respectively. Importantly, these proteins appeared prior to microalbuminuria and may serve as new biomarkers that are able to improve early detection of and new drug development for diabetic-related nephropathy.