| Abstract;S1 proteins present in cell nuclei of various tissues are hnRNP proteins regulating the nuclear function. But the biological function of these proteins are unknown in a process of wound healing. By immunohistochemical techniques with a monoclonal antibody specific for these proteins, the localization of these proteins and the association with an increase in mRNA levels were examined in in vitro and in vivo wound tissues. In in vitro and in vivo wound healing models, a round wound was produced at the center of confluent-seeded 3T3 mouse fibroblasts, and gastric ulcers were produced in male Wistar rats by exposure of 100% acetic acid. Rats were killed on day 3, 5, 7, or 14 after this treatment. S1 proteins were present only in the nuclei of the non-migrating static cells. But, in addition to intra-nuclear localization, these were localized in the cytoplasm of migrating cells at the marginal areas of wound, which were similar to vimentin fibers. In intact gastric tissues, S1 proteins were present in the nuclei of fibroblasts. Whereas, in the ulcerated tissues, the localization of S1 proteins was found both in the nuclei and in the cytoplasm of migrating fibroblasts. Number of fibroblasts possessing these proteins began to increase from day 5 when various mRNA levels such as growth factors, collagens, fibronectin mainly produced by fibroblasts began to increase in the ulcerated tissues. Taken together, S1 proteins associated with vimentin may regulate the synthesis, transport, and/or stabilization of extranucleolar RNA in the migrating fibroblasts during wound healing. (author abst.) |
