The metabolism of hyaluronan in cultured rabbit growth plate chondrocytes during differentiation.
Hyaluronan (HA) is one of the major extracellular matrix components in cartilage. In addition to the biomechanical functions, HA has various important roles in the differentiation of chondrocytes. The purpose of this study was to clarify the nature of HA synthesis during chondrocyte differentiation. Growth plate chondrocytes were isolated from rabbit ribs and cultured in chondrocyte differentiation medium. The amount of HA and HA synthase (HAS) mRNA levels were analyzed for each stage of chondrocyte differentiation by means of high-performance liquid chromatography (HPLC) and real-time PCR, respectively. The distribution of HA in cultured chondrocytes was observed by histochemical staining. The amount of HA, ranging widely in size, was increased substantially during the hypertrophic stage. The expression levels of HAS2 and HAS3 mRNAs were low during the matrix-forming stage. HAS2 mRNA level was substantially enhanced at the pre-hypertrophic stage, whereas HAS3 mRNA level exhibited a slight increase. HAS1 mRNA was not detected. The intensity of HA staining was high around the hypertrophic chondrocytes. These results suggest that HA metabolism in chondrocyte differentiation is regulated by the selective expression of HASs, and HAS2 and the related large size-HA may have a certain association with the hypertrophic changes of chondrocytes.
Suzuki
A
A
Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan.
Tanimoto
K
K
Ohno
S
S
Nakatani
Y
Y
Honda
K
K
Tanaka
N
N
Doi
T
T
Ohno-Nakahara
M
M
Yoneno
K
K
Ueki
M
M
Tanne
K
K
D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D024043:Collagen Type II / Q000378:metabolism; D024121:Collagen Type X / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism; D006132:Growth Plate / Q000166:cytology*; D000076002:Hyaluronan Synthases; D006820:Hyaluronic Acid / Q000378:metabolism*; D007150:Immunohistochemistry; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
D024043:Collagen Type II; D024121:Collagen Type X; D012333:RNA, Messenger; D006820:Hyaluronic Acid; D014453:Glucuronosyltransferase; C491099:Has2 protein, mouse; C491356:Has3 protein, mouse; D000076002:Hyaluronan Synthases