Screening differentially expressed proteins of Meckel’s diverticulum in children

Objective To identify the differentially expressed proteins between Meckel’s diverticulum and small intestine by using two-dimensional gel electrophoresis (2-DE) and mass spectrometry. Methods Meckel’s diverticulum tissue from children with painless bloody stool and small intestinal autopsy tissue were collected and cryopreserved. Total proteins were extracted and separated by 2-DE. The differentially expressed proteins between two groups were compared using image analysis software. The profiles of peptide mass fingerprint (PMF) were acquired after matrix assisted laser desortion/ionization time of flight mass spectrometry (MALDI-TOF-MS) and the proteins identified by searching the database of Pubmed. The expression of differential protein was confirmed by immunohistochemistry between Meckel’s diverticulum tissue from 38 children and small intestine tissue from 16 normal controls. Results Comparative analysis of 2-DE maps revealed 11 differentially expressed proteins between two groups. Five differential proteins were further identified by mass spectrometry. Cyk9 and MHC-I were significantly up-regulated in experimental group than control group while Anx-A2 and EGFR showed significantly higher expressions in control group than in experimental group. Hemoglobin was considered to be intravascular residual in diverticulum. Immunohistochemistry showed that Anx-A2 was positively expressed in normal small intestine of control group and weakly expressed in diverticulum; Cyk9 negatively expressed in control group and highly expressed in diverticulum; MHC-I positively expressed in control group and strongly positively expressed in diverticulum. Conclusions Down-regulated Anx-A2, down-regulated MHC-I and up-regulated Cyk9 may be associated with the pathogenesis of Meckel’s diverticulum. Key words: Meckel diverticulum; Mass spectrometry