ラット骨芽細胞様細胞(ROS17/2.8)に対するBisphosphonate(YH529)の作用

Abstract

Effect of Bisphosphonate (YH529) which is known to suppress bone disuse atrophy on osteoblast was investigated by using ROS17/2.8 cells derived from rat osteosarcoma. The YH529 was added to a culture of ROS17/2.8 cells and further incubated for 48 hr. Production of cAMP (cyclic adenosine 3', 5'-monophosphate) and Alkaline Phosphatase (AP) activity due to PTH (Parathyroid Hormone) stimulus were measured and mRNA (messenger Ribonucleic Acid) in type I collagen (Col I) and in Osteocarcin (OC) were determined using the Northern blot analysis. The results showed that cAMP production due to PTH stimulus decreases with the concentration of YH529 and suggested that the suppression of bone resorption by YH529 was caused not only by the direct action on osteoclast but also by the action through osteoblast coinciding with the osteoclast. AP activity was significantly higher in a YH529 concentration range of 10(exp -11) mol to 10(exp -5) mol than that of the reference group. Col I mRNA expression was also higher in a YH529 concentration range of 10(exp -8) mol to 10(exp -6) mol than that of the reference group, but is nearly similar to that of the reference in a concentration of 10(exp -8) mol. The OC mRNA expression was lower in a YH529 concentration of 10(exp -8) mol and 10(exp -7) mol than, similar to in the concentration of 10(exp -6) mol and higher in the concentration of 10(exp -5) mol than that of the reference. The action of YH529 on osteoblast was found to be diverse and different in concentration.

ラット骨肉腫由来の骨芽細胞様細胞ROS17/2.8を用いて、廃用性骨委縮を抑制することが知られているビスフォスフォネート(YH529)の骨芽細胞に対する作用を検討した。ROS17/2.8細胞の培養液にYH529を添加し、その後さらに48時間培養し、PTH(副甲状腺ホルモン)刺激によるcAMP(サイクリックアデノシン3',5'一リン酸)産生とアルカリホスファターゼ(AP)活性を測定し、またNorthern blot解析によりI型コラーゲン(Col I)とオステオカルシン(OC)のmRNA(メッセンジャー・リボ核酸)を定量した。その結果、PTH刺激によるcAMP産生はYH529の濃度に依存して減少し、YH529の骨吸収抑制作用は破骨細胞に対する直接作用だけでなく、破骨細胞と共存する骨芽細胞を介する作用が存在することを示唆した。AP活性はYH529の10(exp -11)モルから10(exp -5)モルの濃度範囲で対照より有意に高く、Col I mRNA発現も10(exp -8)モルから10(exp -6)モルの濃度範囲で非添加群より有意な高値を示したが、10(exp -5)モルでは対照とほぼ等しくなった。OCのmRNA発現は濃度が10(exp -8)モルと10(exp -7)モルでは対照より低く、10(exp -6)モルで等しくなり、10(exp -5)モルで高値を示した。YH529の骨芽細胞に対する作用は多様であり、濃度によって異なることが示された。