Proteomic analysis of colonic mucosa in a rat model of irritable bowel syndrome

Abstract

Irritable bowel syndrome (IBS) is one of the most common functional disorders of the gastrointestinal tract. It is characterized by abdominal pain and changes in bowel habits. Various studies have investigated the pathophysiologic processes underlying IBS, but the mechanism remains poorly understood. In the present study, we established an IBS model and identified differentially expressed proteins in colon tissue of IBS rats compared with healthy controls by 2-D gel electrophoresis, MALDI-TOF-MS, and Western blot analysis. Our results showed that 13 of the 1396 protein spots on 2-D gel were differently expressed between the IBS and control groups. Ontological analysis of these proteins revealed primary roles in catalytic activity (protein disulfide-isomerase A3, glyoxalase I, cathepsin S, alpha-enolase), structural support (cytokeratin 8), antioxidant activity (peroxiredoxin-6), protein binding (transgelin, serpin peptidase inhibitor B5), and signal transduction (40S ribosomal protein SA). Protein disulfide-isomerase A3 and cytokeratin 8 overexpression in IBS were confirmed by Western blot. The findings indicate that multiple proteins are involved in IBS processes that influence intestinal tract immunity, inflammation, and nerve regulation. Our study provides useful candidate genes and proteins for further investigation.

Proteome changes in the small intestinal mucosa of broilers (Gallus gallus) induced by high concentrations of atmospheric ammonia

“…In the present study, eight differential protein species related to immune response were down-regulated in the treatment group. HMGB1 and HMGB3 serve as immunogenic nucleic acids binding proteins that are generally involved in the nucleic acid receptor-mediated activation of innate immune responses [62,63]; MYO1G is a plasma membrane-associated class I myosin contributing to T-cell activation [64]; SERPINB5 is a tumor suppressor that plays a role in protein binding [65]; IRF3 is a transcription factor that plays distinct role in innate antiviral response [66]; GIT2 is one of regulators of G protein-coupled receptor (GPCR), and loss of GIT2 in vivo leads to an immunodeficient state [67]; HMHA1 is a major target of immune responses also playing a role in T-cell activation [68]; and PLD1 contributes to the essential function of macrophages for protecting against a wide variety of invading microorganisms [69]. Down-regulation of these proteins in the treatment group suggests that, the immunity of gut is under low condition in ammonia-exposed broilers, which increases possibilities of bacterial or viral infection and probably leads to lower growth rate.…”

Preventive Effects of Spirogyra neglecta and a Polysaccharide Extract against Dextran Sodium Sulfate Induced Colitis in Mice

“…Keratin 8 (KRT8) and keratin 18 (KRT18) are the major cytoskeletal intermediate filaments (IFs) in the intestinal epithelia (Ding et al, 2010). KRT8 is the major type II keratin in the small and large intestine, along with type I keratins KRT18, 19, or 20 dependent on the cell and individual tissue.…”

Potential Regulatory Effects of Corticotropin-Releasing Factor on Tight Junction-Related Intestinal Epithelial Permeability are Partially Mediated by CK8 Upregulation

“…CK8 overexpression has been shown to induce degradation and remodelling of actin and tubulin [14-17]; its negative correlation with TJ-related proteins has also been reported [18]. Moreover, in our previous study, CK8 expression was found to be significantly increased in the ileocaecal intestinal mucosa of stressed IBS rats [19]. Furthermore, we found increased expression of CK8 in colonic epithelial cells of rats with IBS, along with the remodelling of actin and dysfunctional distribution of claudin-1 and ZO-1.…”