Cell migration is a fundamental biological process that plays an important role in a wide range of biological and physiological processes. Its deregulation causes or contributes too many diseases, including pulmonary fibrosis. Based on the kinetics of fibroblast migration, we hypothesized that sustained signaling events, in addition to the acute ones, may be needed to support their slow-pace migration and subsequently identified one of the sustained signaling pathways as being critically important for LPA-induced fibroblast migration. In this pathway, LPA acts, through a G12-ARAF-ERK pathway, to transcriptionally upregulate the expression of an ubiquitin E3 ligase RFFL, which polyubiquitinates and destabilizes PRR5L, a specific inhibitor of PKC hydrophobic motif (HM) phosphorylation by mTORC2 (Mammalian target of rapamycin complex 2). The elimination of RFFL leads to sustained PKC HM phosphorylation and activation. This pathway is not only important for fibroblast migration in vitro, also appears to have a key role in pulmonary fibrosis development in a mouse model. In this study, we will investigate the signaling mechanisms downstream of the sustained PKC activation for the regulation of cell migration. We will also validate the importance of this sustained signaling pathway for cell migration in vivo and evaluate the therapeutic potential of a PKC inhibitor in a mouse model of idiopathic pulmonary fibrosis (IPF). IPF, in which LPA-induced fibroblast migration has an important role, is a terminal disease with no effective treatments.
Aberrant fibroblast migration has been shown to play an important role in idiopathic pulmonary fibrosis, a condition that is associated with high morbidity and mortality and refractory to current therapies. This study intends to determine the key molecules and mechanisms for the regulation of fibroblast cell migration and to investigate whether these molecules may be suitable therapeutic targets for the treatment of the disease in a mouse model. Thus, this study may lead to new therapeutic strategies and approaches to this and other fibrosis-related diseases.
