Related Experiment Video
Updated: Jul 17, 2026

Laser Capture Microdissection of Mouse Embryonic Cartilage and Bone for Gene Expression Analysis
Published on: December 18, 2019
Expression of collagens in the otosclerotic bone
H P Niedermeyer1, E T Becker, W Arnold
1Department of Otorhinolaryngology, Head and Neck Surgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
Abstract:
The etiopathogenesis of otosclerosis is still controversially discussed. The major hypotheses discussed are a viral infection on a genetic background and an (autoimmune) collagen disease. The aim of our study was to investigate by immunohistochemistry the expression pattern of collagens within the otosclerotic focus. Stapes footplates from 30 patients with clinical otosclerosis undergoing stapedectomy were formalin fixed, decalcified and paraffin embedded. As controls, 30 autoptic temporal bone specimens were employed. We investigated the expression of collagens I-V with immunohistochemistry. The expression of collagen I showed a diffuse homogeneous distribution with increased staining of the otosclerotic focus. Collagen II was exclusively expressed in chondrocytes including the globuli interossei. The pattern of collagen III in the otosclerotic bone was web-like in contrast to a lamellar pattern in the control bone. The mucoperiosteal layer and connective tissue such as the vessels of the resorption lacunae expressed collagen IV. An increased expression of collagen V around osteocytes was observed in the otosclerotic focus. In conclusion, in the otosclerotic tissue, in comparison with the control bone, a high expression of collagen IV occurred. The immunohistochemical analysis of collagen II, which has been suggested to be implicated in the etiopathogenesis of otosclerosis, revealed no differences between control and otosclerotic bones. The intense staining of the otosclerotic focus with collagen I is in good agreement with an inflammatory process but in contrast with lesions like those in osteogenesis imperfecta.
Related Concept Videos
Growth of Cartilage and Bone Tissue
Bone Formation by Endochondral Ossification
Osteoclasts in Bone Remodeling
Collagens are the Major Structural Proteins of ECM
Connective tissue proper includes loose...
Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Bone Formation by Intramembranous Ossification
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into...
