Department of Geriatric Gastroenterology, Chinese PLA Navy general hospital, Beijing 100048, China.
Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, National Clinical Research Center for Digestive Disease, Beijing 100050, China.
Chin Med J (Engl). 2019 Jan 20;132(2):135-144. doi: 10.1097/CM9.0000000000000003.
Irritable bowel syndrome (IBS) is one of the most common functional intestinal diseases, but its pathogenesis is still unknown. The present study aimed to screen the differentially expressed proteins in the mucosa of colon between IBS with diarrhea (IBS-D) patients and the healthy controls.
Forty-two IBS-D patients meeting the Rome III diagnostic criteria and 40 control subjects from July 2007 to June 2009 in Chinese PLA General Hospital were enrolled in the present study. We examined the protein expression profiles in mucosa of colon corresponding to IBS-D patients (n = 5) and controls (n = 5) using 2-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). Secondly, Western blot and immunohistochemical analysis were carried out to validate the screened proteins in 27 IBS-D patients and 27 controls. Thirdly, high-performance liquid chromatography (HPLC) was further carried out to determine ATP concentration in the mucosa of colon between 10 IBS-D patients and 8 controls. Comparisons between 2 groups were performed by Student's t-test or Mann-Whitney U-test.
Twelve differentially expressed proteins were screened out. The α-enolase (ENOA) in the sigmoid colon (0.917 ± 0.007 vs. 1.310 ± 0.100, t = 2.643, P = 0.017) and caecum (0.765 ± 0.060 vs. 1.212 ± 0.122, t = 2.225, P = 0.023), Isobutyryl-CoA dehydrogenase (ACAD8) in the sigmoid colon (1.127 ± 0.201 vs. 1.497 ± 0.392, t = 7.093, P = 0.008) of the IBS-D group were significantly lower while acetyl-CoA acetyltransferase (CT) in the caecum (2.453 ± 0.422 vs. 0.931 ± 0.652, t = 8.363, P = 0.015) and ATP synthase subunit d (ATP5H) in the sigmoid (0.843 ± 0.042 vs. 0.631 ± 0.042, t = 8.613,P = 0.007) of the IBS-D group was significantly higher, compared with the controls. The ATP concentration in the mucosa of the sigmoid colon in IBS-D group was significantly lower than that of control group (0.470 [0.180, 1.360] vs. 5.350 [2.230, 7.900], U = 55, P < 0.001).
Many proteins related to energy metabolism presented differential expression patterns in the mucosa of colon of the IBS-D patients. The abnormalities in energy metabolism may be involved in the pathogenesis of IBS which deserves more studies to elucidate.
肠易激综合征（IBS）是最常见的功能性肠道疾病之一，但发病机制仍不清楚。本研究旨在筛选 IBS-D 患者与健康对照者结肠黏膜中差异表达的蛋白质。
2007 年 7 月至 2009 年 6 月，解放军总医院共纳入 42 例符合罗马 III 诊断标准的 IBS-D 患者和 40 例对照者。采用二维凝胶电泳（2-DE）和质谱（MS）技术对 5 例 IBS-D 患者和 5 例对照者的结肠黏膜蛋白表达谱进行检测。然后，采用 Western blot 和免疫组化分析对 27 例 IBS-D 患者和 27 例对照者中的筛选蛋白进行验证。其次，进一步采用高效液相色谱（HPLC）法测定 10 例 IBS-D 患者和 8 例对照者结肠黏膜中的 ATP 浓度。采用学生 t 检验或 Mann-Whitney U 检验进行组间比较。
筛选出 12 种差异表达蛋白。IBS-D 组乙缩醛酶（ENOA）在乙状结肠（0.917±0.007 比 1.310±0.100，t=2.643，P=0.017）和盲肠（0.765±0.060 比 1.212±0.122，t=2.225，P=0.023）、异丁酰基辅酶 A 脱氢酶（ACAD8）在乙状结肠（1.127±0.201 比 1.497±0.392，t=7.093，P=0.008）中的表达显著降低，而乙酰辅酶 A 乙酰转移酶（CT）在盲肠（2.453±0.422 比 0.931±0.652，t=8.363，P=0.015）和 ATP 合酶亚基 d（ATP5H）在乙状结肠（0.843±0.042 比 0.631±0.042，t=8.613，P=0.007）中的表达显著升高，与对照组相比。IBS-D 组乙状结肠黏膜中的 ATP 浓度明显低于对照组（0.470[0.180, 1.360]比 5.350[2.230, 7.900]，U=55，P<0.001）。
IBS-D 患者结肠黏膜中许多与能量代谢相关的蛋白质呈现出不同的表达模式。能量代谢异常可能参与了 IBS 的发病机制，值得进一步研究阐明。
