| 摘要: | 骨質疏鬆症的臨床症狀是身體骨組織質量的減少和顯微結構的破壞而導致骨折危險性的增加。停經後由於抑鈣素和動情激素分泌的減少是造成骨質疏鬆症的主要危險因子，導致骨質流失大於形
成速率。治療停經後骨質疏鬆的新藥-福善美(FOSAMAXR)氨基雙磷酸鹽類藥物，在近年來扮演的角色越顯重要。
於本計劃前一年先期研究中我們評估福善美與SDCP 焦磷酸鹽對骨質疏鬆的效果。研究結果由骨灰燼觀察發現，SDCP 比FOSAMAXR更有效地提高骨質密度(BMD)。使疏鬆骨之骨小樑數目提高，可大幅提高骨強度。進一步於本計劃第一年使用體外實驗，利用MTT assay、TUNEL 染色法，電子顯微鏡(SEM、TEM)分別評估SDCP 焦磷酸鹽對蝕骨細胞活性、形態與凋亡現象。
結果顯示於10-4M SDCP 濃度下，骨母細胞數目有明顯增加之現象、而蝕骨細胞數目則有明顯減少之現象。使用免疫螢光反應檢驗顯示蝕骨細胞之凋亡有明顯增加之現象，電子顯微鏡評估顯示高基式體呈顯破壞病分散至細胞質中、稍後蝕骨細胞之細胞核呈顯濃縮及週邊化現象，此外在細胞凋亡之晚期出現細胞核膜破壞且細胞核內容物露出現象。至此我們可認為SDCP 導致蝕骨細胞之凋亡主要以細胞核顯微結構之破壞及細胞內容之崩解為主。
本計劃第二年將使用蝕骨細胞標的蛋白如OPG、OPG-L、Calcitonin receptors (CTR) mRNAs 之cDNA 探針，探討蝕骨細胞與各種不同SDCP 焦磷酸鹽生醫材料之生物反應。經由此實驗，各種不同SDCP 磷酸鈣生醫材料對骨細胞之影響，SDCP 焦磷酸鹽與蝕骨細胞間之生化及分子關係可以得到釐清。而SDCP 焦磷酸鹽是否具有骨質疏鬆症臨床使用的潛力也可以獲得確定。
Osteoporosis is a disease with clinical symptoms
of bone mass loss and deterioration of
microarchitecture on body skeleton, which results
in an increased risk of fractures. The loss of
calcitonin and estrogen production in menopause
is the major risk factor for osteoporosis, causing increased skeletal resorption and relatively decreased bone formation. Bisphosphonates have recently gained an increasing role in the management of osteoporosis. The aminobisphosphonate, FOSAMAX® (alendronate sodium, MSD) has recently been introduced as a new agent for the treatment of postmenopausal osteoporosis. The purpose of this study is to evaluate the effect of FOSAMAX® and SDCP on osteoporosis.
In the pilot study, we have found that the bone
ashes increased significantly after ingestion of
SDCP which is even higher than that of the Fosamax ingestion group. The bone trabeculae
and interconnection between trabeculae were also increased significantly which mean that the
strength of bone architecture also increased
significantly. In the following year, we will evaluate the in-vitro effect of SDCP on the osteoclasts bone cell activities. The cellular morphology, viability and apoptosis of the osteoclasts and osteoblasts will be evaluated by the methods of MTT assay, TUNEL stain, scanning electron microscope (SEM), and transmission electron microscope (TEM) analysis, respectively.
The results showed that at 10-4M SDCP, the
osteoblast cell count increased significantly, while the osteoclast population decreased significantly.
Apoptosis of the osteoclast population was well
demonstrated by immuno-histochemical study. Ultra-structural study showed that the Golgi
apparatus was degraded, or dispersed in the
cytoplasm. Later, osteoclasts revealed pyknotic
nuclei showing condensation and margination of
heterochromatins and DNA fragmentation, which
were typical features of apoptosis. In addition,
disruption of nuclear envelopes leading to leakage of nuclear contents into the cytoplasm
was observed in the late stage of apoptosis. We
concluded that SDCP induces apoptosis of osteoclasts was characterized by ultrastructural
changes of the nucleus accompanied by degradation of cellular organelles.
In the second year’s study, we will use these
markers of the osteoclasts, including the mRNAs of OPG, OPG-L, Calcitonin receptors to evaluate
the molecular and biological response of the
osteoclasts to the SDCP biomaterials.
Through this project, the molecular and biological response of bone cells to SDCP biomaterials will be established. The model of biological response of bone cells to SDCP biomaterials will be elucidated. The possible clinical application of SDCP in the osteoporosis will be established. |
