An immunohistochemical study on the localization of type II collagen in the developing mouse mandibular condyle

Abstract

The present chronological investigation assessed the distribution of type II collagen expression in the developing mouse mandibular condyle using immunohistochemical staining with respect to the anatomy of the anlage of the mandibular condyle, the histological characteristics of which were disclosed in our previous investigation. we analyzed fetuses, obtained by cross breeding of Icr strain mice, between 14.0 and 19.0 days post-conception (dpc) and pups on 1, 3, and 5 days post-natal (dpn) using immunohistochemical staining with 2 anti-type II collagen antibodies. The expression of type II collagen was first detected at 15.0 dpc in the lower part of the hypertrophic chondrocyte zone; thereafter, this type II collagen-positive layer was expanded and intensified (P 1 layer). At 17.0 dpc, we identified a type II collagen-negative layer ( n layer) around the P 1 layer and we also identified another newly formed type II collagen-positive layer (P 2 layer) on the outer surface of the n layer. The most typical and conspicuous 3-layered distribution was observed at 1 dpn; thereafter, there was a reduction in the intensity of expression, and with it, the demarcation between the layers was weakened by 5 dpn. The P 1 layer was derived from the central region of the core cell aggregate of the anlage of the mandibular condyle and participated in endochondral bone formation. The n layer was derived from the fringe of the core cell aggregate of the anlage, formed the bone collar at the side of the condyle by intramembranous bone formation, and showed a high level of proliferative activity at the vault. The P 2 layer was formed from the outgrowth of the n layer, and could be considered as the secondary cartilage. The intensive expression of type II collagen from 17.0 dpc to 3 dpn was detected in the fibrous sheath covering the condylar head, which is derived from the peripheral cell aggregate of the anlage. since its expression in the fibrous sheath was not detected in the neighboring section in the absence of hyaluronidase digestion, some changes in the extracellular matrix of the fibrous sheath appear to participate in the generation of the lower joint space. The results of the present investigation indicate that further studies are required to fully characterize the development of the mouse mandibular condyle.

Evaluation of protein undernourishment on the condylar process of the Wistar rat mandible correlation with insulin receptor expression

“…This was altered in the U group, even with only a slight difference in the articular layer’s thickness. The pre-chondroblastic and chondroblastic layers had the highest IR expression levels, which is also in accordance with their main feature, the abundance of potentially differentiable cells 9 . Moreover, the double phenotypic potential of the CP pre-chondroblastic layer, the capacity to form chondrocytes or osteocytes 30 , makes this a cell-rich area that, consequently, has a higher IR expression level.…”

“…In turn, the impairment of cell support in the CP cartilage layers can disrupt cell proliferation and migration between the layers, thus impairing the mineralization of CM partitions and the deposition of bone matrix. Furthermore, in these animals the capacity of the cartilage to withstand compressive forces may be reduced, as well as the ability to attract cations and water molecules, which provide moisture and promote tissue volume 9 . This would explain the decrease of the size and area of the CPs of malnourished animals observed in this study.…”

Cadmium Toxicity on Chondrocytes and the Palliative Effects of 1α, 25-Dihydroxy Vitamin D3 in White Leghorns Chicken's Embryo

“…COL2A1 is mainly produced by chondrocytes. It is the main protein macromolecule in the cartilage extracellular matrix, ensures the tightness and biomechanical properties of cartilage (44), and is also a marker for proliferative chondrocytes. The main proteoglycan in cartilage is the ACAN macromolecular protein, which interacts with hyaluronic acid to form macromolecular polymers that stably aggregate in the cartilage matrix and replenish water to resist compression and provide good elasticity (45).…”

Observing the development of the temporomandibular joint in embryonic and post-natal mice using various staining methods

“…As the condyle develops continuously upward approaching the glenoid fossa, the mesenchyme differentiates into layers of fibrous tissues, ultimately separating the upper and lower synovial cavities ( 13 ). In addition to cellular proliferation and differentiation, the condyle anlage is configured into a typical secondary cartilage and is superficially covered with a thick layer of flat fibrous cells ( 14 , 15 ). The glenoid fossa exhibits intramembranous ossification, which corresponds to condyle differentiation ( 8 ).…”