Identification of novel bone-resorption markers by osteoclasts in vitro and in vivo.

A recent study aimed to understand the process of bone resorption and identify new biomarkers for this condition. The researchers analyzed the breakdown products resulting from osteoclast action on dentine substrates using liquid chromatography mass spectrometry. They discovered 22 peptide fragment sequences that mapped to collagen proteins, with nine fragments specifically mapping to collagen I alpha-1 chain (COL1A1). Further analysis showed that 14 of these fragments were present in human serum and/or urine from patients with alkaptonuria and lung cancer. These findings suggest a complexity of bone resorption pathways and the potential for new biomarkers beyond existing assays based on Cathepsin K. [Extracted from the article]