Fibulin-5 Contributes to Microfibril Assembly in Human Periodontal Ligament Cells

Abstract

The elastic system fibers comprise oxytalan, elaunin and elastic fibers, which differ in their relative microfibril and elastin content. Human periodontal ligaments (PDL) contain only oxytalan fibers (pure microfibrils) among them. Since fibulin-5 regulates the organization of elastic fibers to link the fibers to cells, we hypothesized that fibulin-5 may contribute to the formation of oxytalan fibers. We used siRNA for fibulin-5 in PDL cell culture to examine the extracellular deposition of fibrillin-1 and -2, which are the major components of microfibrils. Fibulin-5 was labeled on microfibrils positive for fibrillin-1 and -2. Fibulin-5 suppression reduced the level of fibrillin-1 and -2 deposition to 60% of the control level. These results suggest that fibulin-5 may control the formation of oxytalan fibers, and play a role in the homeostasis of oxytalan fibers.

EMILIN-1 regulates the amount of oxytalan fiber formation in periodontal ligaments in vitro

“…An ultrastructural study of EMILIN-1 immunolocalization revealed that the molecule was clearly labeled in oxytalan fibers of the corneal stroma [13]. Moreover, based on the fact that EMILIN-1 can bind with fibulin-5, which is expressed on oxytalan fibers in our PDL culture model [15,16], we hypothesized that EMILIN-1 might contribute to the formation of oxytalan fibers in PDL. In the present study, we used a culture model of pure microfibrils to investigate the role of EMILIN-1 in the development of oxytalan fibers and found that EMILIN-1 colocalizes with oxytalan fibers and regulates their biogenesis.…”

Penalized Regression Versus Random Forest Model in Analyzing High Dimensional Proteomic Data: Diagnosis of IgA Nephropathy

“…Furthermore, FBLN5, as a multifunctional glycoprotein, belongs to the fibulin family that has been reported to have a relationship with elastic system fibers, and contributes in assembly and organization of the extracellular matrix and regulation of microfibril formation (16)(17)(18). Decreased excretion of FBLN5 that is also known as fibulin-5 in IgA nephropathy patients compared with healthy individuals indicates the impairment of elastic system fibers and extracellular matrix (ECM)-cell interaction in this disease.…”

Latent Transforming Growth Factor-β Binding Protein 2 Negatively Regulates Coalescence of Oxytalan Fibers Induced by Stretching Stress

“…Fibulin-5 is the principle molecule involved in the control of elastic fiber formation [11,12]. We have shown previously that fibulin-5 becomes localized on oxytalan fibers and controls their rate of formation [13], and also that fibulin-5 is essential for coalescence of oxytalan fibers in PDL cell culture [10]. However, it is still unclear about the existence of LTBP-2 and the relation between fibulin-5 and LTBP-2 in periodontal tissues.…”

“…Fibulin-5 is also known to be a crucial molecule in the control of elastic fiber formation [11,12]. We have shown previously that fibulin-5 is localized on oxytalan fibers and controls the rate of their formation [13]. Fibulin-5 performs various functions by interacting with certain microfibril-associated molecules [14,15].…”