Kisei Ishizuka

Spectrum of cytokine gene expression in intestinal mucosal lesions of Crohn's disease and ulcerative colitis

Background/Aims: We investigated the mRNA expression of spectrum of cytokines in the colonic mucosa in inflammatory bowel disease (IBD). Methods: The expression of cytokine gene was evaluated by using the reverse transcription-polymerase chain reaction and the radioactivity of amplified cDNA standardized by coamplified β-actin cDNA. Results: Crohn’s disease and ulcerative colitis showed significantly increased expression of IL-1β, IL-6, IL-8 and TNF-α mRNA as compared with controls (p < 0.05). Conclusion: Proinflammatory cytokines such as IL-1β, IL-6, IL-8 and TNF-α are closely involved in the immune abnormalities of inflammatory mucosal lesions in IBD.

Influence of Interleukin-10 on the Interleukin-1 Receptor Antagonist/Interleukin-1β Ratio in the Colonic Mucosa of Ulcerative Colitis

A decrease in the ratio of IL-1ra/IL-1β produced regionally by the colonic mucosa of patients with ulcerative colitis (UC) is believed to play a role in the pathogenesis of UC. To investigate factors influencing intramucosal IL-1ra/IL-1β ratios, we evaluated polymorphism of the IL-1ra gene and the production of mucosal cytokines in Japanese patients with UC. Colonic biopsy specimens of mucosal tissue were placed in organ cultures for 24 h. Then, the supernatant concentrations of IL-1β, IL-1ra, IL-8, IL-4, IL-10, and TGF-β were assayed by ELISA. Genomic DNA was extracted from patient peripheral blood samples, then IL-1ra gene polymorphism was determined using PCR amplification. The mucosa from patients with active stage UC showed a tendency toward a decreased IL-1ra/IL-1β ratio. In the resolving stage, IL-1ra/IL-1β ratios increased with increasing IL-10 and TGF-β concentrations. The addition of human recombinant IL-10 to the culture supernatants produced concentration-dependent inhibition of IL-1β. In Japanese patients with UC, the IL-1ra allele gene 2 phenotype had no effect on the IL-1ra/IL-1β ratio. Our findings suggest that a relative deficiency of IL-10 in patients with UC may contribute to persistent inflammatory changes.

Correlation between serum phospholipase A2 IIA levels and histological activity in patients with ulcerative colitis

HeadingAbstract Background and aims. Phospholipase A2 (PLA2) participates in the regulation of phospholipid metabolism and biosynthesis of eicosanoids, serum levels of PLA2 are suggested to reflect the disease activity in patients with ulcerative colitis (UC). We examined the relationship between histological disease activity and serum levels of PLA2 IIA and also clarified mucosal production sites of PLA2 IIA by immunohistochemistry. Patients and methods. Serum samples from 44 patients with UC, 125 with Crohns diseases (CD), and 68 controls were studied. Biopsy specimens of colonic mucosa obtained from 23 patients with UC were used for assessment of histological activity. The histological score was determined active (1) or inactive (0), and the sum of each histological score from ten segments of the large intestine was assessed as disease activity. The levels of PLA2 IIA in sera were measured by a radioimmunoassay kit using a specific monoclonal antibody; immunohistochemical study was performed using the same monoclonal antibody. Results. The serum PLA2 IIA levels in patients with UC and CD were significantly higher than those of controls. Serum PLA2 IIA levels in UC were closely correlated with histological disease activity. Immunohistochemical study showed the production of PLA2 IIA by the polymorphonuclear cells, macrophages, and colonic epithelial cells. Conclusion. Serum PLA2 IIA is a good candidate for assessing disease activity in UC as one of clinical laboratory tests.

Regional Differences on Production of Chemokines in Gastric Mucosa Between Helicobacter pylori-Positive Duodenal Ulcer and Gastric Ulcer

It is well known that antrum-predominantgastritis and pan-gastritis occurs in the patients withHelicobacter pylori-positive duodenal ulcer (DU) andgastric ulcer (GU), respectively. However, the role of chemokines in the pathogenesis of thesepathologies is unclear. We examined the regionaldifferences in mucosal chemokine production in patientswith DU and GU. The production of interleukin-8 (IL-8), growth-related gene (GRO) α, andmacrophage inflammatory protein (MIP)-1α wasgreater in the antrum than in the corpus in DU patients.In the patients with GU, monocyte chemoattractantprotein (MCP)-1 levels in the mucosa adjacent to ulcer weregreater than those away for the ulcer in the corpus. Thereduction in chemokine production occurring inassociation with the eradication of H. pylori differed between DU and GU patients in the antrum (IL-8,P = 0.0394; GROα, P = 0.0149; MIP-1α, P =0.0246; MCP-1, P = 0.0087). The data imply a differentpathogenesis may exist for the gastritis present in patients with DU and GU occurring in H.pylori-positive individuals.