Abstract
Purpose:
Purpose: Transforming growth factor-beta-induced protein (TGFBIp, also known as βig-H3 and keratoepithelin) is an extracellular matrix protein that plays a role in a wide range of physiological and pathological conditions including diabetes, corneal dystrophy and tumorigenesis. However, the role of TGFBIp signaling in lymphangiogenesis, the growth of lymphatic vessels, is poorly understood. The purpose of this study was therefore to analyze the lymphangiogenic response to TGFBIp and determine if these responses are important for the pathogenesis of lymphangiogenesis-dependent diseases.
Methods:
Methods: We used transwell migration, matrigel tube formation and extracellular matrix adhesion models in order to study the effect of TGFBIp in in vitro lymphangiogenesis. Cytodex three-dimensional bead sprouting assay, 3D spheroid sprouting assay and thoracic duct sprouting assay were utilized to analyzed the function of TGFBIp in in vivo lymphangiogenesis
Results:
Results: In this study, we report a novel role of TGFBIp as a potent lymphatic endothelial activator, promoting lymphangiogenesis. TGFBIp increased adhesion, migration, and morphologic differentiation of human lymphatic endothelial cells (LECs), consistently with increased the LEC sprouting in three-dimensional bead sprouting assay, 3D spheroid sprouting assay and lymphatic ring assay. TGFBIp also increased phosphorylation of intracellular signaling molecules FAK, ERK, AKT and JNK. Furthermore, TGFBIp-induced LEC adhesion, migration and morphologic differentiation were specifically blocked by neutralizing antibody of beta 3 integrin. In addition, TGFBIp-induced LEC sprouting in 3D spheroid sprouting assay was inhibited by neutralizing antibody of beta 3 integrin and pharmacologic inhibitors of FAK, ERK, AKT or JNK. These data demonstrate that TGFBIp promotes lymphangiogenesis by stimulating lymphatic endothelial cells via the beta 3 integrin-FAK-ERK-AKT-JNK signaling pathway.
Conclusions:
Conclusions: These findings open new perspectives for the role of TGFBIp in the pathogenesis of lymphangiogenesis-dependent diseases.
Keywords: 748 vascular endothelial growth factor •
744 tumors •
714 signal transduction