Muramatsu T, Hamano H, Ogami K, Ohta K, Inoue T, Shimono M
Oral Health Science Center, Tokyo Dental College, Chiba, Japan.
Int Endod J. 2005 Nov;38(11):817-21. doi: 10.1111/j.1365-2591.2005.01022.x.
To investigate the expression of osteocalcin mRNA in young and in aged human dental pulp tissue to determine the characteristics of osteocalcin expression.
Human dental pulp tissues of the third molars were obtained from healthy young (17-23 years) and aged (>50 years) subjects, and total RNA was extracted. Osteocalcin mRNA expression was determined by RT-PCR and by quantitative real-time RT-PCR (QRT-PCR). The threshold cycle (Ct) value, which reflects the amount of PCR, was calculated and the difference between the value in young and aged pulp was statistically analysed.
Osteocalcin mRNA was detected in all samples of human dental pulp tissue homogenates by RT-PCR analysis. Osteocalcin mRNA was expressed in young adult dental pulp but was decreased in aged human dental pulp. QRT-PCR analysis also showed a reduced expression of osteocalcin mRNA in aged human pulp. Expression of osteocalcin in young human pulp was significantly higher (about sixfold) than in aged pulp (P<0.01, Mann-Whitney U-test).
Reduction of osteocalcin expression may be associated with the loss of viability in human dental pulp tissue, and may be a characteristic of aged human dental pulps.
研究骨钙素mRNA在年轻和老年人类牙髓组织中的表达，以确定骨钙素表达的特征。
从健康的年轻（17 - 23岁）和老年（>50岁）受试者获取第三磨牙的人类牙髓组织，提取总RNA。通过逆转录聚合酶链反应（RT-PCR）和定量实时逆转录聚合酶链反应（QRT-PCR）测定骨钙素mRNA的表达。计算反映PCR量的阈值循环（Ct）值，并对年轻和老年牙髓中的该值差异进行统计学分析。
通过RT-PCR分析在所有人类牙髓组织匀浆样本中检测到骨钙素mRNA。骨钙素mRNA在年轻成人牙髓中表达，但在老年人类牙髓中表达降低。QRT-PCR分析也显示老年人类牙髓中骨钙素mRNA表达降低。年轻人类牙髓中骨钙素的表达明显高于老年牙髓（约六倍）（P<0.01，曼-惠特尼U检验）。
骨钙素表达的降低可能与人类牙髓组织活力丧失有关，可能是老年人类牙髓的一个特征。
