Fibulin-4 controls LOXL2/tropoelastin complex during elastic fibers formation
Objectives: The enzyme lysyl oxidase (LOX) catalyzes the conversion required for the formation of lysine-derived cross-links found in elastic fibers as well as collagen fibers. The LOX family consists of five members: LOX and lysyl oxidase-like 1-4 (LOXL1-LOXL4). Among the LOX family, LOXL2 in particular has been a focus of interest in view of its cancer-associated functions rather than its role in cross-link formation. Therefore, it remains unclear whether LOXL2 plays a normal cross-linking role in elastin-producing cells in culture. Here we examined whether LOXL2 associates with fibulin-4, a key molecule for deposition of tropoelastin onto microfibrils, in human gingival fibroblasts (HGF).
Methods: Using the RNA interference (RNAi) technique for gene-specific knockdown of fibulin-4, we examined the ability of LOXL2 to bind with tropoelastin in an immunoprecipitation assay.
Results: PCR analysis showed that HGF expressed LOXL2 mRNA. LOXL2 was partly labeled on elastic fibers positive for tropoelastin, suggesting that LOXL2 and tropoelastin formed an extracellular complex. Suppression of fibulin-4 appeared to significantly inhibit formation of the LOXL2/tropoelastin complex in the medium.
Conclusions: These results suggest that fibulin-4 may control formation of the LOXL2/tropoelastin complex, and play a role in the cross-linking of tropoelastin mediated by LOXL2 during normal elastic fiber formation in cultured HGF.
Division: Japanese Division Meeting
Meeting:2012 Japanese Division Meeting (Niigata, Japan) Location: Niigata, Japan
Year: 2012 Final Presentation ID: Abstract Category|Abstract Category(s):Scientific Program
Authors
Yamauchi, Yoshinori
( Fukuoka Dental College, Fukuoka, N/A, Japan
)
Nakatomi, Yuka
( Fukuoka Dental College, Fukuoka, N/A, Japan
)
Nakashima, Kazuki
( Fukuoka Dental College, Fukuoka, N/A, Japan
)
Tsuruga, Eichi
( Fukuoka Dental College, Fukuoka, , Japan
)
Sawa, Yoshihiko
( Fukuoka Dental College, Fukuoka, N/A, Japan
)
Ishikawa, Hiroyuki
( Fukuoka Dental College, Fukuoka, , Japan
)