关键词：骨折；骨质疏松症；骨细胞（生物学）
摘 要：This is a progress report (year 2) for the development of a novel therapeutic drug (salubrinal) for skeletal diseases, focusing on potential treatment of osteoporosis and bone fracture. The study in the second year using animal models and in vitro cell cultures strongly supported salubrinal s action on prevention of bone loss. In animal experiments, we employed three procedures to induce bone loss. They were ovariectomy, hindlimb suspension, and administration of glucocorticoid (prednisolone). In all three models, salubrinal was able to suppress reduction of bone mineral density. In those experiments, salubrinal was administered via subcutaneous injection as well as oral gavage. In in vitro experiments, salubrinal reduced the development of bone-resorbing osteoclasts and promoted the development of boneforming osteoblasts. A provisional patent was submitted for salubrinal s administration for treatment of bone diseases, and the peer-reviewed articles as well as conference abstract were published. In the third year, we will start evaluating the effects of salubrinal on the healing of bone fracture as well as the regulatory mechanism of salubrinal's action.