Role of PLF in bone remodeling following injury.
Rani-S; Barbe-MF; Barr-AE; Litvin-J
FASEB J 2007 Apr; 21(5):A226
INTRODUCTION: Periostin-Like-Factor (PLF) is expressed in developing bone and is up-regulated in adult bones that undergo remodeling due to fractures. PLF over expression by adenovirus in the bone marrow cavity of rats resulted in increased bone formation. Together, these findings suggest that PLF plays an important role in bone remodeling. To study the role of PLF in remodeling bone obtained from the innovative model of Upper Extremity-Work-Related Musculoskeletal Disorder (Barbe et al., 2003) were examined for PLF expression. METHOD: Sprague Dawley rats performed a High Repetition High Force (HRHF) voluntary reaching and pulling task, with a food pellet reward. Task entailed pulling a lever at a target rate of 4 reaches/min with 60% max grip force for 2hrs/day, 3dys/wk, for up to 12 wks. Forelimb bones were subjected to immunostaining and Western blot analysis for PLF. RESULT: PLF was markedly elevated in bones exposed to the HRHF task. PLF was detectable in the cytoplasm of osteoblasts, osteocytes and osteoclasts, and matrix surrounding proliferating and hypertrophied chondrocytes, suggestive of secretion. Western blot analysis showed expression of PLF with task performance. Controls showed no expression of PLF in bone. CONCLUSION: The expression of PLF in bones undergoing remodeling and reorganization suggests that PLF plays a significant role in maintenance of bone after repetitive loading or injury. Source: NIAMS to AEB, and NIOSH to MFB.
Animals; Laboratory-animals; Models; Repetitive-work; Musculoskeletal-system; Musculoskeletal-system-disorders; Age-groups; Force; Tissue-culture; Behavior; Cumulative-trauma; Cumulative-trauma-disorders
The FASEB Journal
Temple University, Philadelphia, Pennsylvania