RANK ligand signaling modulates the matrix metalloproteinase-9 gene expression during osteoclast differentiation

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Experimental Cell Research

DOI:https://doi.org/10.1016/j.yexcr.2006.10.001· OSTI ID:20858070

Sundaram, Kumaran ^[1]; Nishimura, Riko ^[2]; Senn, Joseph ^[1]; Youssef, Rimon F ^[1]; London, Steven D ^[3]; Reddy, Sakamuri V ^[1]

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1. Charles P. Darby Children's Research Institute, 173 Ashley Avenue, Charleston, SC 29425 (United States)
2. Department of Biochemistry, Osaka University Graduate School of Dentistry, Osaka (Japan)
3. College of Dental Medicine, Medical University of South Carolina, Charleston, SC 29425 (United States)

Osteoclast differentiation is tightly regulated by receptor activator of NF-{kappa}B ligand (RANKL) signaling. Matrix metalloproteinase-9 (MMP-9), a type IV collagenase is highly expressed in osteoclast cells and plays an important role in degradation of extracellular matrix; however, the molecular mechanisms that regulate MMP-9 gene expression are unknown. In this study, we demonstrate that RANKL signaling induces MMP-9 gene expression in osteoclast precursor cells. We further show that RANKL regulates MMP-9 gene expression through TRAF6 but not TRAF2. Interestingly, blockade of p38 MAPK activity by pharmacological inhibitor, SB203580 increases MMP-9 activity whereas ERK1/2 inhibitor, PD98059 decreases RANKL induced MMP-9 activity in RAW264.7 cells. These data suggest that RANKL differentially regulates MMP-9 expression through p38 and ERK signaling pathways during osteoclast differentiation. Transient expression of MMP-9 gene (+ 1 to - 1174 bp relative to ATG start codon) promoter-luciferase reporter plasmids in RAW264.7 cells and RANKL stimulation showed significant increase (20-fold) of MMP-9 gene promoter activity; however, there is no significant change with respect to + 1 bp to - 446 bp promoter region and empty vector transfected cells. These results indicated that MMP-9 promoter sequence from - 446 bp to - 1174 bp relative to start codon is responsive to RANKL stimulation. Sequence analysis of the mouse MMP-9 gene promoter region further identified the presence of binding motif (- 1123 bp to - 1153 bp) for the nuclear factor of activated T cells 1 (NFATc1) transcription factor. Inhibition of NFATc1 using siRNA and VIVIT peptide inhibitor significantly decreased RANKL stimulation of MMP-9 activity. We further confirm by oligonucleotide pull-down assay that RANKL stimuli enhanced NFATc1 binding to MMP-9 gene promoter element. In addition, over-expression of constitutively active NFAT in RAW264.7 cells markedly increased (5-fold) MMP-9 gene promoter activity in the absence of RANKL. Taken together, our results suggest that RANKL signals through TRAF6 and that NFATc1 is a downstream effector of RANKL signaling to modulate MMP-9 gene expression during osteoclast differentiation.

• OSTI ID: 20858070
• Journal Information: Experimental Cell Research, Journal Name: Experimental Cell Research Journal Issue: 1 Vol. 313; ISSN 0014-4827; ISSN ECREAL
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
GENES
LIGANDS
LUCIFERASE
MICE
OLIGONUCLEOTIDES
PEPTIDES
PLASMIDS
PROMOTERS
RECEPTORS
STRUCTURAL CHEMICAL ANALYSIS
TRANSCRIPTION FACTORS