We synthesized a galactose derivative, N-octyl-4-epi-␤-valienamine (NOEV), for a molecular therapy (chemical chaperone therapy) of a human neurogenetic disease, ␤-galactosidosis (GM1-gangliosidosis and Morquio B disease). It is a potent inhibitor of lysosomal ␤-galactosidase in vitro. Addition of NOEV in the culture medium restored mutant enzyme activity in cultured human or murine fibroblasts at low intracellular concentrations, resulting in a marked decrease of intracellular substrate storage. Short-term oral administration of NOEV to a model mouse of juvenile G M1-gangliosidosis, expressing a mutant enzyme protein R201C, resulted in significant enhancement of the enzyme activity in the brain and other tissues. Immunohistochemical stain revealed a decrease in the amount of G M1 and GA1 in neuronal cells in the fronto-temporal cerebral cortex and brainstem. However, mass biochemical analysis did not show the substrate reduction observed histochemically in these limited areas in the brain probably because of the brief duration of this investigation. Chemical chaperone therapy may be useful for certain patients with ␤-galactosidosis and potentially other lysosomal storage diseases with central nervous system involvement.

CD22/Siglec-2, an important inhibitory co-receptor on B-lymphocytes, is known to recognize ␣2-6-sialylated glycan as a specific ligand. Here we propose that the ␣2-6-sialylated and 6-GlcNAc-sulfated determinant serves as a preferred ligand for CD22 because the binding of a human B-cell line to CD22 was almost completely abrogated after incubating the cells with NaClO 3 , an inhibitor of cellular sulfate metabolism, and was also significantly inhibited by a newly generated monoclonal antibody specific to the ␣2-6-sialylated 6-sulfo-Nacetyllactosamine (LacNAc) determinant (KN343, murine IgM). The ␣2-6-sialylated 6-sulfo-LacNAc determinant defined by the antibody was significantly expressed on a majority of normal human peripheral B-lymphocytes as well as follicular B-lymphocytes in peripheral lymph nodes. The determinant was also expressed in endothelial cells of high endothelial venules of secondary lymphoid tissues, including lymph nodes, tonsils, and intestine-associated lymphoid tissues, more strongly than on B-lymphocytes, suggesting a role for CD22 in B-cell interaction with blood vessels and trafficking. These results indicate that the ␣2-6-sialylated 6-sulfoLacNAc determinant serves as an endogenous ligand for human CD22 and suggest the possibility that 6-GlcNAc sulfation as well as ␣2-6-sialylation may regulate CD22/Siglec-2 functions in humans.CD22/Siglec-2 (sialic acid-binding immunoglobulin-like lectins) is an important inhibitory receptor on B-lymphocytes. It controls the signaling threshold of B-cell receptors, preventing their overactivation (1-4). It has inhibitory immunoreceptor tyrosine-based inhibitory motifs in its cytoplasmic domain and regulates B-cell receptor signaling by recruiting the tyrosine phosphatase SHP-1 (Src homology 2 domain-containing protein-tyrosine phosphatase-1) (5). It is known to also affect distribution and trafficking of B-lymphocytes, such as in the homing of IgD ϩ B-lymphocytes to the bone marrow (6). Disruption of CD22 is known to result in production of high affinity autoantibodies, an increase in follicular mature B-lymphocytes, and a reduction in the number of marginal zone B-lymphocytes (7, 8).CD22/Siglec-2 is known to specifically bind to its ligand, ␣2-6-sialylated glycan (9 -12). B-lymphocytes themselves significantly express ␣2-6-sialylated glycan on their surface, which can serve as a cis-ligand for endogenous CD22, thus masking the ligand binding activity of CD22 on the majority of B-lymphocytes. CD22/Siglec-2 is proposed to exert trans-interaction with target cells expressing ␣2-6-sialylated glycans only when expression of the endogenous cis-ligand is suppressed or when the trans-ligand on target cells has a significantly higher binding activity than the cis-ligand (13,14). For better understanding of CD22 function, it is important to know the diversity of ␣2-6-sialylated glycans and to find candidate glycans that preferentially bind to CD22.In mice, it has long been known that CD22 prefers the ␣2-6-N-glycolylsialic acid terminus over the ␣2-6-N-acetylsiali...

BackgroundOsteoarthritis (OA) is the most common joint disorder worldwide and one of the leading causes of disability in the elderly. We have investigated the novel sodium hyaluronate derivative chemically linked with diclofenac (DF), diclofenac etalhyaluronate (SI-613), which is a potentially safer and more effective treatment for OA knee pain. In this study, we evaluated the pharmacological effects of SI-613 in experimental arthritis models.MethodsWe compared the analgesic and anti-inflammatory effects of intra-articularly administered SI-613, hyaluronic acid (HA), and of orally administered diclofenac sodium (DF-Na) in rat silver nitrate-induced arthritis model and rabbit antigen-induced arthritis model.ResultsA single intra-articular (IA) administration of SI-613 significantly suppressed pain responses in rats in a dose-dependent manner. The analgesic effects were greater than those of HA, a mixture of DF-Na and HA, or an oral once-daily administration of DF-Na. In the rabbit arthritis model, SI-613 significantly reduced knee joint swelling compared with that in the control group on day 1 after a single IA injection. This significant anti-inflammatory effect was observed until day 28. In the pharmacokinetic study, the DF concentration in the synovium after SI-613 administration reached its maximum concentration of 311.6 ng/g on day 1, and gradually declined to 10 ng/g by day 28. It fell below the lower limit of quantification on day 35. Thus, a clear correlation was found between pharmacokinetics and pharmacodynamics. These results demonstrate that SI-613 exerts its long-lasting and potent anti-inflammatory effect by sustainable release of DF in the knee joint tissues.ConclusionA single IA injection of SI-613 was shown to exert analgesic and anti-inflammatory effects for 28 days in non-clinical pharmacological studies, suggesting that SI-613 will be a promising candidate in the treatment of osteoarthritis pain.

A single-dose IA injection of Gel-200 exerts chondroprotective and anti-inflammatory effects in the experimental OA model, and long-lasting analgesia in the joint pain model, suggesting the beneficial multimodal function of Gel-200 against symptomatic OA patients.