Expression and role of mannose receptor/terminal high-mannose type oligosaccharide on osteoclast precursors during osteoclast formation

in Journal of Endocrinology
Authors:
S Morishima
Search for other papers by S Morishima in
Current site
Google Scholar
PubMed
Close
,
I Morita
Search for other papers by I Morita in
Current site
Google Scholar
PubMed
Close
,
T Tokushima
Search for other papers by T Tokushima in
Current site
Google Scholar
PubMed
Close
,
H Kawashima
Search for other papers by H Kawashima in
Current site
Google Scholar
PubMed
Close
,
M Miyasaka
Search for other papers by M Miyasaka in
Current site
Google Scholar
PubMed
Close
,
K Omura
Search for other papers by K Omura in
Current site
Google Scholar
PubMed
Close
, and
S Murota
Search for other papers by S Murota in
Current site
Google Scholar
PubMed
Close
Free access

Sign up for journal news

Osteoclasts are formed from hematopoietic precursors via cell-cell fusion. We have previously reported that mannose residues are expressed on the outer membranes of monocytes during osteoclast differentiation. In the present study, we have attempted to demonstrate the pattern of expression levels of terminal high-mannose type oligosaccharide and to show that the mannose receptor is expressed on osteoclast precursor cells. Osteoclasts were formed using three different systems, namely mouse bone marrow cell culture, co-culture of mouse spleen cells with stromal cells, and RAW264.7 cell cultures. During osteoclast differentiation, the expression of terminal high-mannose type oligosaccharide gradually increased and then peaked at the stage of fusion in all three systems. Expression of the mannose receptor gradually increased during osteoclast differentiation in bone marrow cells and the co-culture system. In contrast, that in RAW264.7 cells had already been detected in the absence of the soluble receptor activator of NF-kappaB ligand and did not change during osteoclast differentiation. To ascertain whether expression of high-mannose type oligosaccharide is involved in tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell (MNC) formation, glycosidase inhibitors were used on RAW264.7 cell culture. Castanospermine, an inhibitor of glucosidase I, inhibited the TRAP-positive MNCs, and deoxymannojirimycin, an inhibitor of alpha-mannosidase I, increased the TRAP-positive MNC formation. These results indicate that the binding of terminal high-mannose and mannose receptor is important for the process of cellular fusion in osteoclast formation.

 

  • Collapse
  • Expand