Serum levels of cathepsin K decrease with age in both women and men.

Abstract

Bone turnover increases with age. In a previous study, we reported on bone metabolism in young and elderly women and men. The aim of the present investigation was to evaluate potential age- and gender-related changes in cathepsin K, a cysteine protease that plays an important role in the degradation of the organic matrix of bone. Twenty-five healthy premenopausal women, 24 young healthy men, 26 elderly women, and 25 elderly men participated in the study. Elderly women and men had significantly lower cathepsin K levels than younger ones. In both men and women, serum levels of cathepsin K were negatively correlated with age. In men there was a statistically significant negative correlation between serum levels of cathepsin K and osteoprotegerin, which inhibits osteoclast differentiation and activation. No association was found between serum levels of cathepsin K and bone-specific alkaline phosphatase, osteocalcin, or 25-hydroxy vitamin D. Thus, the age-related increase in OPG, which markedly inhibits the expression of cathepsin K, may also reduce serum levels of cathepsin K. Despite the age-related increase in bone resorption, this study shows lower cathepsin K values in elderly women and men than in younger subjects. It might be speculated that a different enzyme could compensate for the decline in cathepsin K during old age.

• Authors: K Kerschan-Schindl, G Hawa, S Kudlacek, W Woloszczuk, P Pietschmann
• Journal: Experimental gerontology (Exp Gerontol) Vol. 40 Issue 6 Pg. 532-5 (Jun 2005) ISSN: 0531-5565 [Print] England
• PMID: 15935595 (Publication Type: Journal Article)

Chemical References

• Glycoproteins
• Osteoprotegerin
• Receptors, Cytoplasmic and Nuclear
• Receptors, Tumor Necrosis Factor
• TNFRSF11B protein, human
• Osteocalcin
• Vitamin D
• 25-hydroxyvitamin D
• Alkaline Phosphatase
• Cathepsins
• Cysteine Endopeptidases
• CTSK protein, human
• Cathepsin K

Topics

• Adult
• Aged, 80 and over
• Aging (blood)
• Alkaline Phosphatase (blood)
• Bone Resorption (metabolism)
• Bone and Bones (metabolism)
• Cathepsin K
• Cathepsins (blood)
• Cysteine Endopeptidases (blood)
• Female
• Glycoproteins (blood)
• Humans
• Male
• Osteocalcin (blood)
• Osteoprotegerin
• Receptors, Cytoplasmic and Nuclear (blood)
• Receptors, Tumor Necrosis Factor (blood)
• Sex Factors
• Vitamin D (analogs & derivatives, blood)