Abstract
Serine racemase (SR) is responsible for the biosynthesis of D-serine (D-Ser), an endogenous co-agonist for the glycine (Gly)-binding site on N-methyl-D-aspartate (NMDA) receptors, from L-Ser in the brain. We have previously demonstrated high expression of SR by chondrocytes in cartilage. In this study, we attempted to elucidate the possible functional role of D-Ser in chondrogenesis. Expression of mRNA and corresponding protein was seen for SR in cultured rat costal chondrocytes, while the addition of L-Ser significantly increased intracellular and extracellular levels of D-Ser. In organotypic cultured mouse embryonic metatarsals isolated before vascularization, SR mRNA was highly localized in hypertrophic and calcified chondrocytes. Exposure to D-Ser not only suppressed several chondrocytic maturation markers, including alkaline phosphatase (ALP) activity, Ca2+ accumulation, nodule formation, and osteopontin expression, in rat chondrocytes, but also delayed chondral mineralization in mouse metatarsals. Either NMDA or Gly alone significantly increased Ca2+ accumulation in cultured chondrocytes, whereas D-Ser significantly prevented Ca2+ accumulation by Gly, but not by NMDA. Gly alone also significantly increased gene transactivation by the introduction of runt-related transcription factor-2 (Runx2) in COS7 cells transfected with NR1 and NR3A subunits, while D-Ser significantly prevented the increase by Gly without affecting the promoter activity of Runx2. In both cultured chondrocytes and metatarsals from NR1-null mice, significant decreases were seen in ALP activity and chondral mineralization, respectively. These results suggest that D-Ser may negatively regulate cellular differentiation through inhibiting NMDA receptors composed of NR1 and NR3A subunits in a manner related to Runx2 transcriptional activity in chondrocytes.
| Original language | English |
|---|---|
| Pages (from-to) | 756-764 |
| Number of pages | 9 |
| Journal | Journal of Cellular Physiology |
| Volume | 220 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Sep 2009 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Clinical Biochemistry
- Cell Biology
- Physiology
Cite this
Interference with cellular differentiation by D-serine through antagonism at N-methyl-D-aspartate receptors composed of NR1 and NR3A subunits in chondrocytes. / Takarada, Takeshi; Takahata, Yoshifumi; Iemata, Mika; Hinoi, Eiichi; Uno, Kyosuke; Hirai, Takao; Yamamoto, Tomomi; Yoneda, Yukio.
In: Journal of Cellular Physiology, Vol. 220, No. 3, 09.2009, p. 756-764.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Interference with cellular differentiation by D-serine through antagonism at N-methyl-D-aspartate receptors composed of NR1 and NR3A subunits in chondrocytes
AU - Takarada, Takeshi
AU - Takahata, Yoshifumi
AU - Iemata, Mika
AU - Hinoi, Eiichi
AU - Uno, Kyosuke
AU - Hirai, Takao
AU - Yamamoto, Tomomi
AU - Yoneda, Yukio
PY - 2009/9
Y1 - 2009/9
N2 - Serine racemase (SR) is responsible for the biosynthesis of D-serine (D-Ser), an endogenous co-agonist for the glycine (Gly)-binding site on N-methyl-D-aspartate (NMDA) receptors, from L-Ser in the brain. We have previously demonstrated high expression of SR by chondrocytes in cartilage. In this study, we attempted to elucidate the possible functional role of D-Ser in chondrogenesis. Expression of mRNA and corresponding protein was seen for SR in cultured rat costal chondrocytes, while the addition of L-Ser significantly increased intracellular and extracellular levels of D-Ser. In organotypic cultured mouse embryonic metatarsals isolated before vascularization, SR mRNA was highly localized in hypertrophic and calcified chondrocytes. Exposure to D-Ser not only suppressed several chondrocytic maturation markers, including alkaline phosphatase (ALP) activity, Ca2+ accumulation, nodule formation, and osteopontin expression, in rat chondrocytes, but also delayed chondral mineralization in mouse metatarsals. Either NMDA or Gly alone significantly increased Ca2+ accumulation in cultured chondrocytes, whereas D-Ser significantly prevented Ca2+ accumulation by Gly, but not by NMDA. Gly alone also significantly increased gene transactivation by the introduction of runt-related transcription factor-2 (Runx2) in COS7 cells transfected with NR1 and NR3A subunits, while D-Ser significantly prevented the increase by Gly without affecting the promoter activity of Runx2. In both cultured chondrocytes and metatarsals from NR1-null mice, significant decreases were seen in ALP activity and chondral mineralization, respectively. These results suggest that D-Ser may negatively regulate cellular differentiation through inhibiting NMDA receptors composed of NR1 and NR3A subunits in a manner related to Runx2 transcriptional activity in chondrocytes.
AB - Serine racemase (SR) is responsible for the biosynthesis of D-serine (D-Ser), an endogenous co-agonist for the glycine (Gly)-binding site on N-methyl-D-aspartate (NMDA) receptors, from L-Ser in the brain. We have previously demonstrated high expression of SR by chondrocytes in cartilage. In this study, we attempted to elucidate the possible functional role of D-Ser in chondrogenesis. Expression of mRNA and corresponding protein was seen for SR in cultured rat costal chondrocytes, while the addition of L-Ser significantly increased intracellular and extracellular levels of D-Ser. In organotypic cultured mouse embryonic metatarsals isolated before vascularization, SR mRNA was highly localized in hypertrophic and calcified chondrocytes. Exposure to D-Ser not only suppressed several chondrocytic maturation markers, including alkaline phosphatase (ALP) activity, Ca2+ accumulation, nodule formation, and osteopontin expression, in rat chondrocytes, but also delayed chondral mineralization in mouse metatarsals. Either NMDA or Gly alone significantly increased Ca2+ accumulation in cultured chondrocytes, whereas D-Ser significantly prevented Ca2+ accumulation by Gly, but not by NMDA. Gly alone also significantly increased gene transactivation by the introduction of runt-related transcription factor-2 (Runx2) in COS7 cells transfected with NR1 and NR3A subunits, while D-Ser significantly prevented the increase by Gly without affecting the promoter activity of Runx2. In both cultured chondrocytes and metatarsals from NR1-null mice, significant decreases were seen in ALP activity and chondral mineralization, respectively. These results suggest that D-Ser may negatively regulate cellular differentiation through inhibiting NMDA receptors composed of NR1 and NR3A subunits in a manner related to Runx2 transcriptional activity in chondrocytes.
UR - http://www.scopus.com/inward/record.url?scp=67650400339&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67650400339&partnerID=8YFLogxK
U2 - 10.1002/jcp.21821
DO - 10.1002/jcp.21821
M3 - Article
C2 - 19452450
AN - SCOPUS:67650400339
VL - 220
SP - 756
EP - 764
JO - Journal of Cellular Physiology
JF - Journal of Cellular Physiology
SN - 0021-9541
IS - 3
ER -