The mechanisms and regulation of procathepsin L secretion from osteoclasts in bone resorption.

Abstract

The secretion mechanisms of cathepsin L from osteoclasts in the process of bone resorption were investigated. The increases in bone pit numbers formed take place by PTH addition in parallel with the increases of cathepsin L and/or L-like proteinase activities in the culture medium of bone cells, and these were suppressed by the addition of calcitonin. The Z-Phe-Arg-MCA hydrolysing activity increased in the medium through the effect of PTH is considered to be a kind of procathepsin L by Western blotting analysis, and was suppressed by calcitonin addition. Furthermore, monensin inhibited not only the PTH-induced pit formation, but also cysteine proteinase activity in osteoclasts. Therefore, the procathepsin L excreted might be transferred from endothelial reticulum via Golgi and/or via lysosomes.

• Authors: K Tagami, H Kakegawa, H Kamioka, K Sumitani, T Kawata, B Lenarcic, V Turk, N Katunuma
• Journal: FEBS letters (FEBS Lett) Vol. 342 Issue 3 Pg. 308-12 (Apr 11 1994) ISSN: 0014-5793 [Print] England
• PMID: 8150090 (Publication Type: Journal Article)

Chemical References

• Enzyme Precursors
• Parathyroid Hormone
• Calcitonin
• Monensin
• Cathepsins
• procathepsin L
• Cathepsin L

Topics

• Animals
• Biological Transport (drug effects)
• Bone Resorption
• Calcitonin (pharmacology)
• Cathepsin L
• Cathepsins (metabolism)
• Enzyme Precursors (metabolism)
• Macrophages (enzymology)
• Male
• Monensin (pharmacology)
• Osteoclasts (enzymology)
• Parathyroid Hormone (pharmacology)
• Rats
• Rats, Sprague-Dawley