SPECIFIC RESPONSES OF HUMAN MANDIBULAR OSTEOCYTE TO MECHANICAL LOADING

1999年：本年度的研究计划是比较下颌骨和股骨骨细胞对牵张的反应，但我们在下颌骨骨细胞对牵张和甲状旁腺激素（1-34）PTH的反应方面获得了有趣的结果，因此我们报道了（B.B.R.Cvol.264）. 2000：为了比较下颌骨骨细胞和股骨骨细胞的反应，我们准备了两种机械加载程序。一种是低强度脉冲超声，其由换能器产生，声波加速骨折愈合系统（SAFHS，Exogen，Inc.）最近我们报道了（B.B.R，C vol.268），另一个是Flexercell Strain Unit（Flexercell Corp.）已报道（内分泌学第137卷和B.B.R.C.第246卷）。两者都已经放在神奈川牙科拼贴。）1，人骨细胞培养物（J.Bone Miner.Res.vol.10和Calcif. Tissue Int.vol.57）2，骨细胞对机械负荷的反应（1999）拉伸（内分泌学vol.137和B.B.R.C.vol.246）和PTH（1-34） ...更多信息 加入浓度（2000）低强度脉冲超声（B.B.R.C.vol.268），加入PTH（1-34），用引物（GAPDH，骨钙素，ALP，IGF-1，考克斯-2等）对在1，0 min（对照）; 2，15 min ; 3，1 hr; 5，6 hr; 6，24 hr收获的细胞的每组6个总RNA样品进行PCR分析。（J.Bone Miner.Res.vol.10和Calcif.TissueInt.vol.57）。我们使用本补助金支持的Thamal Cycler进行RT-PCR分析。3，结果和讨论（1999）在PTH存在的情况下，骨钙素mRNA的上调稳态水平进一步上调（在开始拉伸后1小时）。另一方面，在PTH的存在下（在3小时拉伸后3小时），下调的信使水平进一步下调（B.B.R.C.vol.264）。在应对过程中，协同作用可以是正面的，也可以是负面的。由此，我们推测相关机制在PTH信号通路和拉伸激活的机械传导通路之间起作用。（2000）在骨髓基质来源的ST 2细胞中研究了暴露于低强度脉冲超声20分钟的影响。他们对超声波的反应是IGF mRNA、骨钙素和骨sia-loprotein mRNA水平升高。这些信息的上调表达以双相方式出现（B.B.R.C.vol.268）。相反，在从股骨移植的骨细胞中，超声不能有效诱导成骨细胞的合成代谢反应。但最近我们获得了一个新的结果，这是有效的，导致骨基质形成，现在我们讨论这一结果，并有更多的研究在其他标本尽快。4，结论我们的结果表明，从神经嵴的下颌骨细胞表现出不同的反应，从股骨的机械负荷，在口腔颌面部的破坏性成骨等骨再生手术中取得良好的效果还需要进一步的研究。少

1999 : The schedule of this year is to compare the response of mandibular osteocytes with femoral one to stretching.But we obtained an interesting result to charactorise the response of mandibular osteocytes to stretching and parathyroid hormone, (1-34) PTH.So we reported (B.B.R.C vol.264).2000 : Concerning to the comparison the response of mandibular osteocytes with femoral, we prepared two way of mechanical loading procedures. One is the low-intensity pulsed ultrasound which is generated with the transducer, the Sonic Accelerated Fracture Healing System (SAFHS, Exogen, Inc.) recently we reported (B.B.R,C vol.268), the other is Flexercell Strain Unit (Flexercell Corp.) already reported (Endocrinology vol.137 and B.B.R.C.vol.246). Both are already placed on Kanagawa Dental Collage.)1, Human osteocytic cell culture (J.Bone Miner.Res.vol.10 and Calcif. Tissue Int.vol.57)2, Osteocytic cells to mechanical loading(1999) Stretching (Endocrinology vol.137 and B.B.R.C.vol.246), and PTH (1-34) … More was added.(2000) Low-intensity pulsed ultrasound (B.B.R.C.vol.268), and PTH (1-34) was added.Each set of six total RNA samples from the cells harvested at : 1, 0 min (control) ; 2, 15 min ; 3, Ihr, 5, 6 hrs ; 6, 24 hrs were subjected to PCR analysis with primers (GAPDH, Osteocalcin, ALP, IGF-1, COX-2, et al.)(J.Bone Miner.Res.vol.10 and Calcif.Tissue Int.vol.57). We used the Thamal Cycler which was supported by this grants-in-aid to do RT-PCR analysis.3, Result and Discussion(1999) The upregulated steady-state level of osteocalcin mRNA is further upregulated in the presence of PTH (at 1 h after the initiation of stretching). On the other hand, the downregulated level of the message is further downregulated in the presence of PTH (at 3 h after the 3-h stretching)(B.B.R.C.vol.264). The synergy can be either way, positive or negative, in the course of the response. From this, we presume that related mechanisms are at work between the PTH signaling pathways and the mechanotransduction pathways activated by Stretching.(2000) The effects of 20-min exposure to low-intensity, pulsed ultrasound were investigated in ST2 cells of bone marrow stromal origin. They responded to ultrasound with elevated levels of IGF mRNAs, osteocalcin, and bone sia-loprotein mRNAs. The upregulated expression of these messages appeared in a biphasic manner (B.B.R.C.vol.268). On the contrary, in osteocytes hervested from femoral bone, ultrasound was not effective to induce an anabolic reaction of osteogenic cells. But recently we obtained a new result that was effective to lead bone matrix formation, now we discuss this results and have to investigate more in other samples as soon as possible.4, ConclusionOur result suggest that Mandibular osteocytes from neural crests show diferent response to mechanical loading from femoral bone, we need more investigations to obtein good result in bone regenerative operations such as distruction osteogenesis in oral and maxillofacial area. Less