Assessment of expression level of intestinal antibacterial peptides in ulcerative colitis as a biomarker for pouchitis

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K08611
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 55020:Digestive surgery-related
• Research Institution: Tohoku University
• Principal Investigator: Watanabe Kazuhiro 東北大学, 大学病院, 助教 (30569588)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 潰瘍性大腸炎 / 家族性大腸腺腫症 / 回腸嚢炎 / 抗菌ペプチド / 腸内細菌 / 短鎖脂肪酸 / 有機酸 / 大腸全摘

Outline of Final Research Achievements

Mucosal samples of ileal pouch in patients with ulcerative colitis (UC) and familial adenomatous polyposis (FAP) who underwent total colectomy and ileal pouch anal anastomosis were collected. The quantification of mRNA for intestinal-derived antibacterial proteins/peptides (Resistin- like moleculeβ(RELM-β)、Human β defensin 1 (hBD1)、and Human α defensin 5 (HD5)) was performed by the RT-PCR method. There was no significant difference in the expression levels between UC and FAP, but the expression levels of RELM-β and hBD1 were significantly reduced in cases of 2 years or more compared to within 1 year after stoma closure (p=0.04, p=0.02). Similarly, the expression levels of RELM-β and hBD1 were significantly reduced in cases 2 years or more compared to cases 1-2 years after stoma closure (p=0.04, p=0.02). There was no clear difference between the presence and absence of pouchitis.

Free Research Field

消化器外科

Academic Significance and Societal Importance of the Research Achievements

潰瘍性大腸炎の大腸全摘・回腸嚢肛門吻合術後の合併症として回腸嚢炎があり、術後管理の大きな問題となっている。回腸嚢炎の原因は不明であるが、抗菌剤が著効することから腸内細菌叢との関連が示唆されている。今回、腸管から分泌される内因性抗菌タンパク/ペプチド(AMPs)に着目し検討を行い、経時的にAMPsの発現量が変化することを示した。腸内細菌は、経時的に健常人の細菌叢に近づく傾向を認める一方で、潰瘍性大腸炎ではPrevotella属の増加などの特徴を認めており、これらが回腸嚢炎の発症に関与している可能性が示唆された。