| Project/Area Number |
15590616
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Gastroenterology
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| Research Institution | Akita University |
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Principal Investigator |
IIZUKA Masahiro Akita University, School of Medicine, Assistant Professor, 医学部, 教授 (00241654)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Sumio Akita University, School of Medicine, Professor, 医学部, 教授 (20138225)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Crohn's disease / Etiology / Cathepsin / Peroxiredoxin / peroxiredoxin |
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| Research Abstract |
We constructed under informed consent cDNA library derived from the affected intestine of a Crohn's disease (CD) patient in the bacteriophage λ gt11, and screened 1.5 millions clones in the library with the serum from a typical CD patient. Consequently, we identified nine positive clones. Among these positive clones, we further selected one clone (C150) to which the CD patient serum most strongly responded. C150 mRNA has 462 nucleotides (GenBank accession number DQ480128). C150 is highly homologous with both peroxiredoxin-6 (AA1-39) and cathepsin K (AA41-154). Next, C150 was expressed as a fusion protein with Glutathione S-transferase (GST). Then, we performed Western Blot using sera from 22 CD (mean age 25.0±7.4 yrs (SD)) and 16 non-inflammatory bowel disease (IBD) patients (31.3±12.1), and found that a larger percentage of CD patients (45.4%) had antibody to the fusion protein compared to non-IBD patients (18.8%). C150 has a stop codon at 40th AA position, and we suggested that patients' sera probably responded to the epitope within the 1st-39th amino acids. Then, we constructed a peptide of the 2nd-21st amino acids of C150, which has 95% similarity with human peroxiredoxin-6, and ELISA between this peptide and each serum from 19 CD (mean age 27.9±9.1yrs), 11 ulcerative colitis (39.6±14.4) and 10 non-IBD patients (44.3±13.9) was performed. Accordingly, mean titer of the ELISA was significantly increased in CD patients compared to non-IBD patients (p=0.0166).
It has been shown that peroxiredoxin-6 has an antioxidant function. It has also been shown that oxidative stress might be a key contributor to pathogenesis of CD. From the results of our study, we hypothesize that systemic anti-oxidant function might be attenuated in some CD patients and such defective antioxidant function might be involved in the pathogenesis of CD.
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