scholarly journals Triiodothyronine (T3) does not induce Rankl expression in rat Ros 17/2.8 cells

2008 ◽  
Vol 52 (1) ◽  
pp. 109-113 ◽  
Author(s):  
Patrícia P. Saraiva ◽  
Silvania S. Teixeira ◽  
Célia Regina Nogueira ◽  
Carlos Roberto Padovani

Osteoclastogenesis may be regulated via activation of the RANK/RANKL (receptor activator of nuclear factor-kappa B/ receptor activator of nuclear factor-kappa B ligand) system, which is mediated by osteoblasts. However, the bone loss mechanism induced by T3 (triiodothyronine) is still controversial. In this study, osteoblastic lineage rat cells (ROS 17/2.8) were treated with T3 (10-8 M, 10-9 M, and 10-10 M), and RANKL mRNA (messenger RNA) expression was measured by semiquantitative RT-PCR. Our results show that T3 concentrations used did not significantly enhance RANKL expression compared to controls without hormone treatment. This data suggests that other mechanisms, unrelated to the RANK/RANKL system, might be to activate osteoclast differentiation in these cells.

2001 ◽  
Vol 170 (1) ◽  
pp. 175-183 ◽  
Author(s):  
T Kukita ◽  
A Kukita ◽  
T Watanabe ◽  
T Iijima

Although calcitonin has been clinically utilized as a primary treatment for several metabolic bone diseases, its inhibitory effects against osteoclastic function diminish after several days owing to the calcitonin 'escape phenomenon'. We have previously found a unique cell-surface antigen (Kat1-antigen) expressed on rat osteoclasts. Here we show evidence that, in the presence of calcitonin, the Kat1-antigen is involved in osteoclastogenesis. Treatment of bone marrow cultures for forming osteoclast-like cells with anti-Kat1-antigen monoclonal antibody (mAb Kat1) provoked a marked stimulation of osteoclast-like cell formation only in the presence of calcitonin but not in its absence. Osteoclastogenesis stimulated by the receptor activator of nuclear factor kappa B (NF-kappaB) ligand/osteoclast differentiation factor was further augmented by mAb Kat1 in the presence of calcitonin. Furthermore, even in the presence of the osteoprotegerin/osteoclast inhibitory factor, mAb Kat1 induced osteoclast-like cell formation. Our current data suggest that the Kat1-antigen is a molecule that is distinct from receptor activator of NF-kappaB. The presence of the unique Kat1-antigen on cells in the osteoclast lineage appears to contribute to the fine regulation of osteoclastogenesis in vivo. Expression of this cell-surface molecule in cells in the osteoclast lineage may partly explain the mechanism responsible for the escape phenomenon.


2021 ◽  
Vol 22 (3) ◽  
pp. 741-747
Author(s):  
Hui Chua ◽  
Sharifah Emilia Tuan Sharif ◽  
Wan Faisham Nu’man Wan Ismail ◽  
Muhamad Syahrul Fitri Zawawi ◽  
Sarimah Abdullah

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