NEW EXPERIMENTAL SYSTEM : CO-EXISTANCE OF BONE FORMATION AND RESORPTION IN VITRO

新实验系统：体外骨形成与吸收的共存

• 批准号: 05557080
• 负责人: KASUGAI Shohei
• 金额: $ 2.75万
• 依托单位: TOKYO MEDICAL AND DENTAL UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05557080/
• 关键词: BONE; OSTEOBALST; PROSTAGLANDIN; RECEPTOR; SIGNAL TRANSDUCTION; 骨芽細胞; 破骨細胞; 骨髄; プロスタグランディン

Administration of prostaglandin E_2 (PGE_2) has anabolic effects in bone, we examined the effects of PGE_2 on bone-like mineralized tissue formation in rat bone marrow stromal cell culture. Addition of PGE_2 at early stage of culture increased the amount of mineralized tissue whereas addition of PGE_2 at later stage, just before mineralization, inhibited mineralized tissue formation, indicating that effects of PGE_2 is depending on the stage of osteoblastic differentiation. Then, we tried to find the signal transduction pathway of the anabolic effect of PGE_2 at the early stage of this culture system, and our experiment revealed the involvement of cAMP-dependent signal transduction in this phenomenon. On the other hand, PGE_2 increases intracellular Ca, and stimulates or inhibits cAMP production through PGE receptor subtypes ; EP_1, EP_2 and EP_3, respectively. These receptor subtypes have been recently cloned. We investigated the expression of these receptor subtypes in bone tissue. RT-PCR revealed that EP_1, EP_2 and EP_3 were expressed in rat calvaria and that osteoblastic cells (MC3T3-E1) expressed EP_1 and EP_2. In situ hybridization analysis using cryosection of neonatal calvariae revealed that EP_2 was expressed by osteoblasts and cells not in contact with bone, probably including preosteoblasts. EP_2 expression was observed at an early stage in calvarial development, and also in rat bone marrow cell culture. It has been established that PGE_2 response accompanying cAMP production is one of the characteristics of osteoblasts. Our results indicate that this phenotype appears at an early stage of osteoblastic differentiation and bone development.

前列腺素E_2 （PGE_2）在骨中具有合成代谢作用，我们观察了PGE_2对培养大鼠骨髓基质细胞形成骨样矿化组织的影响。在培养早期添加PGE_2可增加矿化组织的数量，而在矿化前添加PGE_2可抑制矿化组织的形成，说明PGE_2的作用与成骨细胞分化的阶段有关。然后，我们试图找到PGE_2在该培养体系早期的合成代谢作用的信号转导途径，我们的实验揭示了camp依赖的信号转导参与了这一现象。另一方面，PGE_2增加细胞内Ca，并通过PGE受体亚型刺激或抑制cAMP的产生；EP_1, EP_2, EP_3。这些受体亚型最近被克隆出来。我们研究了这些受体亚型在骨组织中的表达。RT-PCR结果显示，EP_1、EP_2和EP_3在大鼠颅骨中表达，成骨细胞MC3T3-E1表达EP_1和EP_2。新生儿颅骨冷冻切片原位杂交分析发现，EP_2在成骨细胞和非骨接触细胞中表达，可能包括成骨前细胞。EP_2在颅骨发育早期及大鼠骨髓细胞培养中均有表达。PGE_2反应伴随cAMP的产生是成骨细胞的特征之一。我们的研究结果表明，这种表型出现在成骨细胞分化和骨发育的早期阶段。

项目成果

S.Kasugai,他: "Expression of prostaglandin Ereceptor subtypes in bone:Expression of EP_2 in bone development" Bone. (印刷中).

S. Kasugai 等人：“骨中前列腺素受体亚型的表达：骨发育中 EP_2 的表达”（正在出版）。

Kasugai Set al: "Signal transduction pathway of anabolic effect of PGE_2 in rat bone marrow stromal cell culfure" Japanese Journal of Pharmacology. 64 (Suppl 1). 116P (1994)

Kasugai Set al：“大鼠骨髓基质细胞培养物中PGE_2合成代谢作用的信号转导途径”日本药理学杂志。

春日井 昇平 他: "ラット骨髄ストローマ細胞培養系におけるProstaglandin E_2の骨様組織形成促進作用の機序に関する研究" 歯科基礎医学会雑誌. 35(補). 156 (1993)

Shohei Kasugai等人：“前列腺素E_2在大鼠骨髓基质细胞培养系统中促进骨样组织形成的机制的研究”日本基础牙科医学会杂志35（增刊）156。

Kasugai S et al. :"Expression of prostaglandin E receptor subtypes in bone : Expression of EP_2 in bone development." Bone. (in press.).

春日井 S 等人。

春日井昇平,他: "骨組織におけるProstag landin E_2 受容体サブタイプの発現に関する研究" 歯科基礎医学会誌. 36(補). 203 (1994)

Shohei Kasugai等：“骨组织中Prostag landin E_2受体亚型的表达研究”日本基础牙科医学会杂志36（增刊）203（1994）。