- Paper Report
- Open Access
Determination of three isoforms of RANKL
- Riako Masuda1
© Biomed Central Ltd 2001
- Received: 19 June 2001
- Published: 27 July 2001
- T cells
RANKL (receptor activator of nuclear factor-?B ligand; also known as osteoprotegerin ligand, osteoclast differentiation factor, tumour necrosis factor-related activation-induced cytokine) induces the differentiation of T cells and osteoclasts. Therefore it has been suggested that the RANK-RANKL pathway plays an important role in cellular interaction at sites of bone destruction in rheumatoid arthritis (RA).
The authors found two new isoforms of RANKL:RANKL2 has a shorter intracellular domain than the original RANKL, and RANKL3 lacks a transmembrane domain. Although mRNAs for all three isoforms were detected in both the bone marrow cell line ST2 and the preosteoblastic cell line MC3T3-E1, only the expression of RANKL2 was suppressed by treatment with 1a,25-dihydroxyvitamin D3 and dexamethasone. In thymus, CD4-CD8-, CD4+CD8- and CD4-CD8+ cells expressed all three isoforms of RANKL, but RANKL2 could not be detected in CD4+CD8+ cells. These results suggest that the regulation of osteoclastogenesis and T-cell differentiation by RANKL might be more complex than previously thought.
Northern hybridization, RT-PCR, transfection, immunofluorescence