Malays. Appl. Biol. (2018) 47(6): 87–96
STRUCTURAL CHANGES AND THE DIFFERENTIAL
EXPRESSION OF OSTEOPROTEGERIN (OPG) AND RECEPTOR
ACTIVATOR OF NUCLEAR FACTOR kB LIGAND (RANKL)
IN SUBCHONDRAL BONE DURING THE DEVELOPMENT
OF OSTEOARTHRITIS
AKMA AZMIERA AKMAN1, AIN AISYAH TALIB1, AZIRAH MD YUSOF1, KAMARUL ARIFFIN KHALID2,
NURUL ASYIQIN YUSOF3, RADIAH ABDUL GHANI1, ASMAH HANIM HAMDAN4 and
ZAITUNNATAKHIN ZAMLI1*
1Department of Biomedical Science, Kulliyyah of Allied Health Sciences,
International Islamic University Malaysia, Bandar Indera Mahkota, 25200, Pahang, Malaysia
2Department of Orthopaedic, Kulliyyah of Medicine, International Islamic University Malaysia,
Bandar Indera Mahkota, 25200, Pahang, Malaysia
3Department of Basic Medical Sciences, Kulliyyah of Pharmacy,
International Islamic University Malaysia, Bandar Indera Mahkota, 25200, Pahang, Malaysia
4Department of Pathology & Laboratory Medicine, Kulliyyah of Medicine,
International Islamic University Malaysia, Bandar Indera Mahkota, 25200, Pahang, Malaysia
*E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Accepted 14 October 2018, Published online 31 December 2018
ABSTRACT
Osteoarthritis is a degenerative joint disease that is characterized by subchondral bone changes. These changes may be associated with bone remodelling, which involve coordinative functions between bone formation and resorption markers such as osteoprotegerin (OPG) and receptor activator of nuclear factor kB ligand (RANKL), respectively. Previous studies have shown that the structural changes were different between the subchondral bone plate and trabecular bone. However, the expression of bone formation and bone resorption markers underlying the differences between these two regions has yet to be determined. Hence, the present study aims to determine the structural changes and expressions of OPG/RANKL in the subchondral bone plate and trabecular bone during the development of osteoarthritis in Dunkin Hartley guinea pigs. Eighteen tibias were scanned using a micro-computed tomography at three different time points; 10, 20 and 30 weeks of age to determine their subchondral bone plate and trabecular bone thickness. Immunohistochemistry and histopathology methods were conducted to determine the expression of OPG/RANKL and microscopic osteoarthritis score, respectively. The results showed that subchondral bone plate and trabecular bone thickness were greater in the medial than the lateral side of the tibial plateau, and increased significantly with ageing (p < 0.01). In addition, across the time points, the OPG/RANKL ratio of medial Sbp initially increased, before decreasing at the final time point. In contrast, the OPG/RANKL ratio of medial Tb was initially constant but then decreased at 30 weeks of age. Interestingly, a significant correlation was observed between the subchondral bone plate thickness and OPG/RANKL ratio with microscopic osteoarthritis scores (r = 0.5,p </= 0.05), suggesting that the subchondral bone plate plays an important role in the pathogenesis of osteoarthritis.
Key words: Osteoarthritis, osteoprotegerin, receptor activator of nuclear factor kb ligand, subchondral bone plate, trabecular bone
