Cellular and Molecular Biology


Cytokeratin-positive subserosal myofibroblasts in gastroduodenal ulcer; another type of myofibroblasts

L. Guo1,3, N. Kuroda1, H. Nakayama1, E. Miyazaki1, Y. Hayashi1, M. Toi1, M. Hiroi1 and H. Enzan1

1Department of Pathology, Program of Bioregulation and Genetics, Kochi Medical School, Kochi, Japan, 2Department of Molecular Pathology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan and 3Department of Pathology, Peking University Health Science Center, Beijing, China

Offprint requests to: Limei Guo, Department of Pathology, Peking University Health Science Center, Xueyuan Road-38, Haidian District, Beijing 100083, China. e-mail: guolimei@bjmu.edu.cn

Summary. To investigate the distribution and origin of alpha-smooth muscle actin (ASMA)-positive stromal cells in the perforation of human gastroduodenal ulcers. Perforative lesions of 24 surgically resected gastroduodenal ulcers were examined immunohistochemically for ASMA, HCD, CD34, CD31, CAM5.2 and HMW-CK, and double staining of ASMA and CAM5.2 was also performed. In addition, to determine the cell source of collagen, in situ hybridization of collagen I mRNA was performed. In the normal gastroduodenal wall, the reticular network of CD34-positive stromal cells was identified in the muscularis mucosa, submucosa, muscular propria, and subserosa. In the subepithelial area, many myofibroblasts were observed, whereas no CD34-positive stromal cells were seen. In areas neighboring ulcerative lesions, no CD34-positive stromal cells were observed, but a significant number of myofibroblasts were present there. In the deep layer of ulceration, numerous fusiform or stellate stromal cells strongly positive for ASMA and CAM5.2 were observed in the subserosal area around the perforation. In the same site, many cells co-expressing ASMA and CAM5.2 were identified by double staining. In contrast, in the surface layer of ulceration, stromal cells expressing only ASMA were observed. The cytokeratin-positive subserosal myofibroblastic cell in human gastroduodenal ulcer is a novel type of myofibroblast. Histol Histopathol 21, 697-704 (2006)

Key words: Myofibroblast, Subserosal cell, Cytokeratin, Peptic ulcer