Static Compressive Loading Reduces the mRNA Expression of Type II and X Collagen in Rat Growth-Plate Chondrocytes During Postnatal Growth
- 1 January 2005
- journal article
- research article
- Published by Informa UK Limited in Connective Tissue Research
- Vol. 46 (4-5), 211-219
- https://doi.org/10.1080/03008200500344058
Abstract
The mechanisms by which chondrocytes modulate longitudinal bone growth are not well understood. This in vitro study investigated the effects of loading on the mRNA expression pattern of key molecular components of the growth-plate related to the extracellular matrix (type II and type X collagen) and the PTH-PTHrP feedback loop. Short-term static compressive loading was applied to rat proximal tibial growth-plate explants. Four age groups at specific developmental stages were investigated. The spatial variation in the mRNA expression was compared among loaded explants, their contralateral sham controls, and uncultured growth plates from normal animals. Basic cell metabolism (18S rRNA) was unaffected by load. Results indicated a narrower spatial distribution of mRNA expression of type II collagen throughout the growth plate; similarly, a narrowed distribution of expression of type X collagen was noted in the lower hypertrophic zone of the growth-plate. This suggests that mechanical compression influences chondrocytes of the hypertrophic zone to alter their expression of specific genes encoding proteins of the extracellular matrix, while PTH-PTHrP receptor mRNA, a regulatory protein, remained unaffected by loading. The effects of compression were similar at the different stages of growth, suggesting that additional factors may be involved in the clinical progression of skeletal deformities observed during growth spurts. Although this study was done in vitro and limited to static loading, it furthers our understanding of growth-plate mechanobiology as a first step toward providing a scientific rationale for treating progressive musculoskeletal deformities.Keywords
This publication has 16 references indexed in Scilit:
- Chondrocyte Proliferation of the Cranial Base Cartilage upon in vivo Mechanical StressesJournal of Dental Research, 2002
- Expression of Indian Hedgehog, Parathyroid Hormone-Related Protein, and Their Receptors in the Postnatal Growth Plate of the Rat: Evidence for a Locally Acting Growth Restraining Feedback Loop After BirthJournal of Bone and Mineral Research, 2000
- Different Bone Growth Rates Are Associated With Changes in the Expression Pattern of Types II and X Collagens and Collagenase 3 in Proximal Growth Plates of the Rat TibiaJournal of Bone and Mineral Research, 2000
- Differential growth by growth plates as a function of multiple parameters of chondrocytic kineticsJournal of Orthopaedic Research, 1996
- Mechanical Modulation of Vertebral Body GrowthSpine, 1996
- Compressive Mechanical Properties of the Human Anulus Fibrosus and Their Relationship to Biochemical CompositionSpine, 1994
- Effects of distraction and compression on proliferation of growth plate chondrocytes: A study in rabbitsActa Orthopaedica, 1993
- Linear relationship between the volume of hypertrophic chondrocytes and the rate of longitudinal bone growth in growth platesJournal of Orthopaedic Research, 1991
- Skeletal structural adaptations to mechanical usage (SATMU): 3. The hyaline cartilage modeling problemThe Anatomical Record, 1990
- Biomechanical activity of the growth plateSurgical and Radiologic Anatomy, 1984