November 12, 2014
Notes: Thandassery, Ragesh Babu
Yadav, Thakur Deen
Dig Dis Sci. 2014 Jun;59(6):1316-21. doi: 10.1007/s10620-013-3000-7. Epub 2013 Dec 28.
Author Address: Department of Gastroenterology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Reference Type: Journal Article
Record Number: 4797Author: Tian, R., Wang, R. L., Xie, H., Jin, W. and Yu, K. L.
Title: Overexpressed miRNA-155 dysregulates intestinal epithelial apical junctional complex in severe acute pancreatitis
Journal: World J Gastroenterol
Date: Dec 7
Short Title: Overexpressed miRNA-155 dysregulates intestinal epithelial apical junctional complex in severe acute pancreatitis
Alternate Journal: World journal of gastroenterology : WJG
ISSN: 2219-2840 (Electronic)
Accession Number: 24363519
Keywords: Acute Disease
Amine Oxidase (Copper-Containing)/blood
Disease Models, Animal
Mice, Inbred BALB C
Severity of Illness Index
Tumor Necrosis Factor-alpha/blood
Zonula Occludens-1 Protein/metabolism
rho GTP-Binding Proteins/genetics/metabolism
Abstract: AIM: To investigate whether miRNA-155 (miR-155) dysregulates apical junctional complex (AJC) protein expression in experimental severe acute pancreatitis (SAP). METHODS: Twenty-four male BALB/c mice were randomly assigned to two groups: the SAP group (n = 12) receiving sequential intraperitoneal injection of 50 microg/kg caerulein and 10 mg/kg lipopolysaccharide over 6 h, and the control group (n = 12) receiving intraperitoneal injection of normal saline. Animals were sacrificed 3 h following the last injection for collection of blood samples and pancreas and distal ileal segment specimens. Routine pancreas and intestine histology was used to assess SAP pathology and intestinal epithelial barrier damage. Levels of serum amylase, diamine oxidase (DAO), and tumor necrosis factor (TNF)-alpha were determined using commercial kits. Total RNA samples were isolated from intestinal epithelial specimens and reversely transcribed into cDNA. miR-155 and RhoA mRNA expression profiles were determined using quantitative real-time polymerase chain reaction. Target genes for miR-155 were predicted using the miRTarBase database, RNA22 and PicTar computational methods. Western blotting was performed to quantitate the protein expression levels of the target gene RhoA, as well as zonula occludens (ZO)-1 and E-cadherin, two AJC component proteins. RESULTS: Intraperitoneal injection of caerulein and lipopolysaccharide successfully induced experimental acute pancreatic damage (SAP vs control, 10.0 +/- 2.0 vs 3.2 +/- 1.2, P < 0.01) and intestinal epithelial barrier damage (3.2 +/- 0.7 vs 1.4 +/- 0.7, P < 0.01). Levels of serum amylase (21.6 +/- 5.1 U/mL vs 14.3 +/- 4.2 U/mL, P < 0.01), DAO (21.4 +/- 4.1 mg/mL vs 2.6 +/- 0.8 mg/mL, P < 0.01), and TNF-alpha (61.0 +/- 15.1 ng/mL vs 42.9 +/- 13.9 ng/mL, P < 0.01) increased significantly in SAP mice compared to those in control mice. miR-155 was significantly overexpressed in SAP intestinal epithelia (1.94 +/- 0.50 fold vs 1.03 +/- 0.23 fold, P < 0.01), and RhoA gene containing three miR-155-specific binding sites in the three prime untranslated regions was one of the target genes for miR-155. RhoA (22.7 +/- 5.8 folds vs 59.6 +/- 11.6 folds, P < 0.01), ZO-1 (46 +/- 18 folds vs 68 +/- 19 folds, P < 0.01), and E-cadherin proteins (48 +/- 15 folds vs 77 +/- 18 folds, P < 0.01) were underexpressed in SAP intestinal epithelia although RhoA mRNA expression was not significantly changed in SAP (0.97 +/- 0.18 folds vs 1.01 +/- 0.17 folds, P > 0.05). CONCLUSION: TNF-alpha-regulated miR-155 overexpression inhibits AJC component protein syntheses of ZO-1, and E-cadherin by downregulating post-transcriptional RhoA expression, and disrupts intestinal epithelial barrier in experimental SAP.