論文名稱:

骨內給予骨塑型蛋白四對局部骨密度

 

The Effect of Intraosseous BMP4 Administration on Local Bone Density

研究生:

蕭文凱  Wen-Kai Hsiao

 

(以作者名查詢陽明大學館藏系統)

 

(以作者名查詢全國圖書書目資訊網)

指導教授:

陳恆理  Hen-Li Chen

        學位類別:

碩士

        學校名稱:

國立陽明大學

系所名稱:

口腔生物研究所

            學號:

39317002

          學年度:

94

          語文別:

中文

          出版年:

95

關鍵字:

局部股密度  local bone density

 

骨塑型蛋白四  bone morphogentic proteins

 

骨內給予  intraosseous

全文說明:

(本論文 20080717 對校內公開)

 

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摘要:

中文摘要

   
 

    骨質疏鬆症是臨床治療常遇到的症狀,局部骨密度的不足可能大幅影響牙科人工植牙的成功率。提高局部骨密度雖具重要臨床意義,但目前針對提高局部骨密度之相關研究甚少。在測試生長因子之促進骨生成特性的研究顯示局部骨內給予生長因子可增加局部骨密度,惟生長因子在體內半衰期短,作用有限,故近期發展基因治療來長期在局部給予生長因子,其中又以病毒性基因治療之效率較高。骨塑型蛋白四(bone morphogenetic proteins 4BMP4 ) 在體外可誘導間葉幹細胞(mesenchymal stem cell)分化為骨母細胞osteoblast),在動物體內也可以促進骨頭及軟骨生成。本研究利用帶有人類骨塑型蛋白四基因之腺病毒adenovirus-BMP4)注入局部骨內,評估利用病毒基因治療局部給予生長因子以增加局部骨密度之可行性。

 

    本研究中構築帶有人類BMP4Ad-BMP4)或LacZAd-LacZ)基因的腺病毒,並以鹼性磷酸酶活性測試及X-gal染色法分別檢測感染重組腺病毒之C2C12細胞表現BMP4β-galactosidase的活性。在體內測試方面,在16紐西蘭母兔施行卵巢切除術並等18以模仿停經後骨質疏鬆症,接著分兩組將Ad-BMP4Ad-LacZ分別注入左後腿股骨內,並在手術後一、二、四與八利用骨密度儀pDEXA分析局部骨密度,並配合X光片、免疫組織化學染色、組織切片檢查。實驗結果顯示在體外實驗Ad-BMP4可以誘導C2C12增加鹼性磷酸酶的活性,當注射至左腿股骨內在四週及八週後均可提高局部骨密度(p0.05),並且四週及八週時BMP4組的局部骨密度比LacZ組分別高61%、35%,此研究結果支持以基因療法給予生長因子以增加局部骨密度的可行性。

   
 

Abstract

   
 

Osteoporosis is common in clinical practice. Poor local bone density may significantly compromise the success rate for dental implants. Though there are needs for increasing local bone density, rare researches were focused on improving local bone density. Previous studies indicated that local intraosseous administration of growth factors may increase local bone density. However, the effects are often limited by the short half life of growth factors. Thus gene therapy approach has been developed to enable sustained release of growth factors locally. Bone morphogenetic protein 4 (BMP4) is capable of inducing the osteoblastic differentiation of mesenchymal stem cells in vivo and promoting bone formation in vivo. The purpose of this study is to determine the feasibility of increasing local bone density by viral gene therapy via intraosseous injection of adenoviral vectors encoding BMP4.

 

Adenoviruses encoding human BMP4 (Ad-BMP4) or LacZ (Ad-LacZ) were constructed. C2C12 alkaline phosphatase assay and X-gal staining were used to verify the activity of expressed BMP4 and β-galactosidase respectively. Sixteen New Zealand female rabbits received ovariectomy and waited for 18 weeks before surgery to mimic the condition of postmenopausal osteoporosis. Rabbits were divided into two groups and received Ad-BMP4 or Ad-LacZ into left femurs respectively. Local bone density at the injection site was evaluated by dual energy X ray absorptiometry (at 1, 2, 4, and 8 weeks postoperatively), radiographic, immunohistochemistric and histologic assays to determine if the adenoviral gene therapy can enhance the local bone density. The experimental results indicated that Ad-BMP4 transduction increase alkaline phosphatase activity of C2C12 cells in vitro. Intraosseous administration of Ad-BMP4 significantly increased local bone density at both 4- and 8-week (p<0.05) by 61% and 35% respectively when compare to the LacZ control group. The results of this study support the feasibility of increasing local bone density by growth factors delivered via gene therapy strategy.