An immunohistochemical study of matrix proteins in the craniofacial cartilage in midterm human fetuses.
Immunohistochemical localization of collagen types I, II, and X, aggrecan, versican, dentin matrix protein (DMP)-1, martix extracellular phosphoprotein (MEPE) were performed for Meckel's cartilage, cranial base cartilage, and mandibular condylar cartilage in human midterm fetuses; staining patterns within the condylar cartilage were compared to those within other cartilaginous structures. Mandibular condylar cartilage contained aggrecan; it also had more type I collagen and a thicker hypertrophic cell layer than the other two types of cartilage; these three characteristics are similar to those of the secondary cartilage of rodents. MEPE immunoreactivity was first evident in the cartilage matrix of all types of cartilage in the human fetuses and in Meckel's cartilage of mice and rats. MEPE immunoreactivity was enhanced in the deep layer of the hypertrophic cell layer and in the cartilaginous core of the bone trabeculae in the primary spongiosa. These results indicated that MEPE is a component of cartilage matrix and may be involved in cartilage mineralization. DMP-1 immunoreactivity first became evident in human bone lacunae walls and canaliculi; this pattern of expression was comparable to the pattern seen in rodents. In addition, chondroid bone was evident in the mandibular (glenoid) fossa of the temporal bone, and it had aggrecan, collagen types I and X, MEPE, and DMP-1 immunoreactivity; these findings indicated that chondroid bone in this region has phenotypic expression indicative of both hypertrophic chondrocytes and osteocytes.
Tokyo Medical and Dental University. sshibata.mfa@tmd.ac.jp.
S
S
Shibata
Y
Y
Sakamoto
O
O
Baba
C
C
Qin
G
G
Murakami
B H
BH
Cho
D053674:Aggrecans / Q000096:biosynthesis; D000818:Animals; D002356:Cartilage / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism; D024042:Collagen Type I / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis; D005260:Female; D005333:Fetus / Q000378:metabolism; D005865:Gestational Age; D006023:Glycoproteins / Q000096:biosynthesis; D006801:Humans; D008335:Mandibular Condyle / Q000378:metabolism*; D051379:Mice; D010750:Phosphoproteins / Q000096:biosynthesis; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D051381:Rats
D053674:Aggrecans; D024042:Collagen Type I; C513309:DMP1 protein, human; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; C486579:MEPE protein, human; D010750:Phosphoproteins; D018809:Proliferating Cell Nuclear Antigen; D003094:Collagen