Abstract: The present inventors discovered that knockout mice whose S1-5 gene function is lost develop age-related diseases or symptoms. In such knockout mice, bone mineral content, bone mineral density, and bone strength were found to be decreased, and the number of osteoclasts in bone tissues was found to be increased. Analysis of osteoclast-forming ability using bone marrow cells derived from the knockout mice revealed that osteoclast-forming ability is enhanced and osteoclasts are larger in the knockout mice than in wildtype mice. When purified S1-5 protein was added to this in vitro system, osteoclast-forming ability was inhibited. Furthermore, administration of purified S1-5 protein to osteoporotic model mice showed that this protein has the effect of improving osteoporosis. The above findings demonstrate that S1-5 protein is useful for treating and preventing age-related diseases such as osteoporosis.

Abstract: The present invention provides a decoy nucleic acid for the Synoviolin gene promoter. Also provided is the decoy nucleic acid can inhibit the promoter activity by binding to the transcription factor of the Synoviolin gene promoter. It also provides a decoy nucleic acid as expressed in (a) a decoy nucleic acid consisting of a nucleotide sequence as shown in SEQ ID NO: 11 or 12; and it also provides (b) a decoy nucleic acid consisting of a nucleotide sequence as shown in SEQ ID NO: 11 or 12 having deletion, substitution or addition of one or several nucleotides and has the function of inhibiting Synoviolin gene promoter activity.

Abstract: The present invention relates to an antibody against synoviolin or a fragment thereof for providing a monoclonal antibody capable of recognizing a part of synoviolin, which monoclonal antibody is capable of inhibiting the auto-ubiquitination of synoviolin.

Abstract: The present invention relates to an assay method for determining a auto-ubiquitination activity of synoviolin, comprising reacting synoviolin and ubiquitin in a reaction system containing them and determining an amount of ubiquitin binding to synoviolin, to a method of screening a substance capable of regulating such an activity, and to a kit for auto-ubiquitination assay of synoviolin.

Abstract: The present invention provides a method for suppressing cancer comprising activating tumor suppressor gene p53 or protein p53 for localizing the protein to the nuclear, and a pharmaceutical composition comprising a substance that promotes activation of tumor suppressor gene p53 or protein p53.

Abstract: The present invention provides an apoptosis-inducing agent or a therapeutic agent for autoimmune diseases, comprising a substance that induces ER stress; and a method for inhibiting the proliferation of cells, wherein the cells (for example, synoviocytes) are treated with the inducing agent.

Abstract: The present invention provides a pharmaceutical composition containing a substance which inhibits the proliferation of synovial tissue or synovial cells and the interleukin-6 production. It also provides a pharmaceutical composition for inhibiting the proliferation of synovial tissue or synovial cells and the interleukin-6 production, which is useful for diagnosing and treating at least one selected from the group consisting of rheumatoid arthritis, fibrosis, arthritis, cancers, and cerebral neural diseases. In addition, it provides a method for inhibiting the proliferation of synovial cells and the interleukin-6 production by inhibiting the expression of hsHRD3 in synovial cells.

Abstract: The present invention provides a nerve cell differentiation inducing drug containing a Synoviolin expression inhibitor which is a useful drug for treatments of neural disorders, particularly Alzheimer's disease, Parkinson's disease, peripheral nerve disorders or spinal injury. As Synoviolin expression inhibitors, there are siRNA against gene coding Synoviolin (SEQ ID No. 1 or 2), or shRNA, a decoy nucleic acid that inhibits the promoter activity by binding to the transcription factor of the promoter of the Synoviolin gene or antisense oligonucleotide against gene coding the Synoviolin. The nerve cell differentiation inducing drug of the present invention is used for the treatment of neural disorders including Alzheimer's disease, Parkinson's disease, peripheral nerve disorders or spinal injury.