Studies On Identification Of Differently Expressed Proteins In Rat's Developmental Pancreas

Diabetes is one of the serious diseases which threaten the humans' health. Most of the patients have their functional cells damaged, so the overall understanding of the normal process of pancreatic development is quite helpful for us to known the regulation mechanism of the pancreatic functional cells and will make a basic direction for the future clinical study. Many of the former studies used the technique of gene knock-out to study the role of specific gene in the process of pancreatic development, but there were few studies about the developmental process of total pancreas in the aspect of proteomics.This study used the technique of two dimensional gel electrophoresis (2DE) and mass spectrometry to investigate the protein expression profiles and their changes of rat's pancreas at the stages of embryonic day 15.5(E15.5), E18.5, neonatal and adult.Using the technique of micro-isolation, we obtained the pancreatic tissue of these four stages. After the total proteins were abstracted, we separated them by the two dimensional gel electrophoresis. After silver staining, we analyzed the 2DE images with ImageMaster software to get the differently expressed proteins and their respective isoelectric pointand molecular weight. We also used the mass spectrometry to identify these proteins and get their peptide mass finger printings. The good 2DE patterns with high resolution and reproducibility were obtained. The difference among every group was obvious. We picked up 19 spots from differently expressed profile between the E18.5 and adult. We obtained their ideal MS results except for one spot which could not be identified because of too little quantity. Among the 18 spots, seven of them were alpha-fetoprotein(AFP); five of them were pancreatic lipase related protein 1(PLRP1) precursor; one of them were tubulin beta 5; two of them were protein disulfide isomerase(PDI); the other three were peroxiredoxin 4, pancreatic trypsin V-A precursor and similarity of FLN29 gene products. AFP was specifically expressed in rat embryonic and neonatal pancreas. Its expression was the highest in E18.5 and the lowest in adult pancreas. We also used the technique of Western Blot to investigate the expression of AFP in the four stages, the results matched with 2D.Overall, the analysis of differently expressed proteins is helpful for us to study the proteins and the molecular markers related with pancreatic development. It will help us to elucidate the molecular mechanism of pancreatic development and provide the scientific evidence for the prevention, diagnosis and treatment of diabetes.