Related Experiment Video
Updated: Jul 15, 2026

Using Inducible Osteoblastic Lineage-Specific Stat3 Knockout Mice to Study Alveolar Bone Remodeling During Orthodontic Tooth Movement
Published on: July 21, 2023
Signaling by way of type IB and II bone morphogenetic protein receptors regulates bone formation in otospongiosis
Goetz Lehnerdt1, Klaus Alfred Metz, Sokratis Trellakis
1Department of Otorhinolaryngology, University of Duisburg-Essen, Essen, Germany. goetz.lehnerdt@uni-due.de
Hypothesis:
The main goal of this study was to perform an immunohistologic analysis of bone morphogenetic protein receptors (BMPR) in otospongiosis.
Background:
BMP-2, -4, and -7 play an essential role in bone formation and repair. They do so as well in otosclerosis. It has been shown that these BMPs are traceable in osteocytes and osteoclasts in the active phase of otosclerosis (otospongiosis). The role of the different BMP receptors in otosclerotic bone transformation has not been previously analyzed.
Methods:
The posterior parts of the stapes footplates, collected during partial stapedectomies in 35 patients with clinical otosclerosis, were analyzed for histologic otosclerotic lesions after hematoxylin staining. Immunohistochemical analysis was performed using polyclonal immunoglobulin G antibodies for BMPR-IA, -IB, and -II, as well as biotinylated secondary antibodies, avidin-biotin-peroxidase complex reaction, and alkaline phosphatase staining with nitroblue-tetrazolium-chloride.
Results:
Seventeen of 35 (49%) specimens contained otosclerosis, but only 5 of these exhibited an otospongiotic phase. The abundant osteoblasts and osteoclasts in these cases showed distinct immunochemical staining for BMP-2, -4, and -7. In two cases, there could also be found an immense positive staining for BMPR-IB and modest staining for BMPR-II, whereas BMPR-1A always remained negative.
Conclusion:
It was demonstrated for the first time that in otospongiosis, the actions of the BMPs are mediated through BMPR-IB and BMPR-II. To determine this role in detail, further investigations, especially for the phosphorylated Smad proteins within the BMP dependent mediator cascade, will be necessary.
Related Concept Videos
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...
Bone Formation by Endochondral Ossification
Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Bone Remodeling
TGF - β Signaling Pathway
Notch Signaling Pathway
The Notch gene came into the limelight in 1914 after the discovery that its mutation in Drosophila melanogaster leads to a serrated (or "notched") wing margin phenotype. It was not until 1985...

