Resumen:
TWEAK regulates multiple physio-pathological processes in fibroblasts such as fibrosis. It also induces migration and invasion in tumors and it can activate p38 MAPK in various cell types. Moreover, p38¿ MAPK promotes migration and invasion in several cancer cells types and in mouse embryonic fibroblasts (MEFs). However, it remains unknown if TWEAK could promote migration in fibroblasts and whether p38¿ MAPK might play a role. Our results reveal that TWEAK activates ERKs, Akt, and p38¿/ß MAPKs and reduces secreted Fibulin 3 in MEFs. TWEAK also increases migration and invasion in wt and p38¿ deficient MEFs, which indicates that p38¿ MAPK is not required to mediate these effects. In contrast, ERKs inhibition significantly decreases TWEAK-induced migration and Fibulin 3 knock-down mimics TWEAK effect. These results indicate that both ERKs activation and Fibulin 3 down-regulation would contribute to mediate TWEAK pro-migratory effect. In fact, the additional regulation of ERKs and/or p38ß as a consequence of Fibulin 3 decrease might be also involved in the pro-migratory effect of TWEAK in MEFs. In conclusion, our studies uncover novel mechanisms by which TWEAK would favor tissue repair by promoting fibroblasts migration.
