Temporal Expression of SOX9 and Type II Collagen in Spheno-Occipital Synchondrosis of Mice after Mechanical Tension Stimuli

Abstract

Objective: To associate the expressions of SOX9 and type II collagen during growth in the synchondrosis with and without tensile stress in order to understand the role of these factors in the growth of cartilage in spheno-occipital synchondrosis. Materials and Methods: Sixty 1-day-old male BALB/c mice were randomly divided into experimental and control groups. Each group was subdivided again into five different time points which were 6, 24, 48, 72, and 168 hours. Each subgroup consisted of five mice. Each mouse was sacrificed using an overdose of pentobarbitone sodium. The synchondroses were aseptically removed and incubated in a 24-well plate with or without tensile stress in tissue culture. Tissue sections were stained immunohistochemically to quantitatively analyze the expression of SOX9 and type II collagen. Results: There was a statistically significant increase of 57% (P Ͻ .001) in the expression of SOX9 between the experimental and control groups at 24 hours, followed by a significant increase of 44.4% (P Ͻ .001) in the expression of type II collagen at 72 hours. Conclusions: SOX9 may play an important role for early differentiation of chondrocytes and increase the expression of type II collagen, a major component of the extracellular matrix, during the growth of cartilage in the spheno-occipital synchondrosis.

The effect of quercetin on expression of SOX9 and subsequent release of type II collagen in spheno-occipital synchondroses of organ-cultured mice

“…Cendekiawan et al 13 used tensile stress to stimulate expression of Sox9 and type II collagen, showing the same pattern of Sox9 and type II collagen expression from 6 hours to 168 hours. In the experimental groups, the expression of Sox9 and type II collagen reached a maximum level at 24 hours and 72 hours, respectively.…”

“…This is in contrast to the 57% (P , .001) increase reported in the study by Cendekiawan et al In addition, we found an increased expression of 22.99% (P , .001) of type II collagen versus the 44.4% (P , .001) in their analysis. 13 This suggests 1 mM of quercetin is capable of producing a similar, but attenuated, amount of Sox9 and type II collagen expression compared with tensile stress. Although the overall effect of an increase of type II collagen expression is not big and the period of exposure of quercetin is short (several days), further research is needed to optimize the dosage of quercetin and to investigate the long-term effect of quercetin on growth.…”

“…[11][12][13] These studies showed that the expression of certain growth markers, such as Sox9 and type II collagen, can be enhanced by application of mechanical force. Furthermore, they revealed that organcultured spheno-occipital synchondrosis can provide a good model to study the effect of various agents on endochondral growth.…”

Relationships Between Cranial Base Synchondroses and Craniofacial Development: A Review

“…Mutations in genes encoding FGFRs have been identified as causes of Apert syndrome, Crouzon syndromes and Pfeiffer syndromes [5]. As for environmental effects, the use of an organ culture technique has revealed that synchondrosis is responsive to tensile mechanical stress and increased expression of various factors related to growth stimulation [115][116][117]. This series of studies was the first to show that growth across the synchondrosis can be modified mechanically.…”

Appropriate cyclic tensile strain promotes biological changes of cranial base synchondrosis chondrocytes

“…delivered tensile forces non‐invasively to the maxillae of rabbits and concluded that cyclic tension could stimulate the proliferation of chondrocytes and promote the expression of some extracellular matrix (ECM) . Organ culture studies found that mechanical stress applied to CBS elicited a series of molecular biological reactions including upregulated expression of Cbfa1, VEGF, PTHrP and Sox9 . Compared with an animal model and organ culture, direct mechanical protraction on cranial base synchondrosis chondrocytes (CBSCs) is more targeted and allows researchers to conduct further studies at the gene level .…”