Proteimics of hyperlipidemia-associated pancreatitis using differential gel electrophoresis and tandem mass spectrometry: experiment with rats

Abstract

Objective To analyze the injury mechanism of hyperlipidemia-associated acute pancreatitis utilizing proteomics. Methods Ten SD rats were fed with high fat feed to establish hyperlipidemic models, and 10 SD rats were fed with normal feed to be used as control group. Six weeks later 5 rats from each group were intraperitoneally injected with caendin to establish acute edematous pancreatitis models, and 5 rats from each group were injected with bile acid taurocholate into pancreatic duct to cause acute necrotizing pancreatitis. Nine hours after the establishment of models the rats were killed with their pancreases taken out. Differential protein analysis was performed using two-dimensional differential ingel electrophoresis (2D-DIGE) and tandem mass spectrometry (MALDI-TOF/TOF). Immunohistochemical method was adopted to confirm the significantly changed proteins. Results Rat models of hyperlidemiaassociated acute edematous pancreatitis and rat models of hyperlidemia-associated acute necrotic pancreatitis were well established. Fifty-nine spots were detected by DeCyder Analysis Software between acute necrotic pancreatitis with and without hyperlipidemia samples and 39 markedly changed protein spots were identified by MALDI-TOF-TOF. Twelve spots were detected between the samples of acute edematous pancreatitis with and without hyperlipidemia and 7 of them were identified. Differentially expressed proteins in hyperlipidemiaassociated pancreatitis included pancreatic enzymes, such as lipase, amylase, and alpha-l-antiproteinase,ER stress and calcium influx related proteins including GRP78, HSP60 and protein disulfide isomerase.Other proteins associated with DNA replication and damage repair, apoptosis, cell metabolism, circulatory dysfunction, and signal transduction were identified in hyperlipidemia-associated acute pancreatitis.Conclusion Some proteins related to ER stress, apoptosis, circulatory dysfunction and signal transduction show differential expression in acute pancreatitis with hyperlipidemia. Hyperlipidemia intensifies acute pancreatitis through various ways. ER stress-related proteins such as GRP78, HSP60, protein disulfide isomerase, and calreticulin can be regarded as biomarkers of early diagnosis and target of further treatment in severe acute pancreatitis. Key words: Pancreatitis, acute necrotizing; Hyperlipidemias ; Electrophoresis, gel, twodimensional; Endoplasmic reticulum