Matrix decomposition in meta-analysis for extraction of adverse event pattern and patient-level safety profile.

The purpose of assessing adverse events (AEs) in clinical studies is to evaluate what AE patterns are likely to occur during treatment. In contrast, it is difficult to specify which of these patterns occurs in each patient. To tackle this challenging issue, we constructed a new statistical model including nonnegative matrix factorization by incorporating background knowledge of AE-specific structures such as severity and drug mechanism of action. The model uses a meta-analysis framework for integrating data from multiple clinical studies because insufficient information is derived from a single trial. We demonstrated the proposed method by applying it to real data consisting of three Phase III studies, two mechanisms of action, five anticancer treatments, 3317 patients, 848 AE types, and 99,546 AEs. The extracted typical treatment-specific AE patterns coincided with medical knowledge. We also demonstrated patient-level safety profiles using the data of AEs that were observed by the end of the second cycle.

Involvement of sphingosine-1-phosphate and S1P1 in angiogenesis: analyses using a new S1P1 antagonist of non-sphingosine-1-phosphate analog.

Chemical lead 2 (CL2) is the first non-sphingosine-1-phosphate (Sph-1-P) analog type antagonist of endothelial differentiation gene-1 (Edg-1/S1P(1)), which is a member of the Sph-1-P receptor family. CL2 inhibits [(3)H]Sph-1-P/S1P(1) binding and shows concentration-dependent inhibition activity against both intracellular cAMP concentration decrease and cell invasion induced by the Sph-1-P/S1P(1) pathway. It also inhibits normal tube formation in an angiogenesis culture model, indicating that CL2 has anti-angiogenesis activity. This compound improved the disease conditions in two angiogenic models in vivo. It significantly inhibited angiogenesis induced by vascular endothelial growth factor in a rabbit cornea model as well as the swelling of mouse feet in an anti-type II collagen antibody-induced arthritis model. These results indicate that the Sph-1-P/S1P(1) pathway would have an important role in disease-related angiogenesis, especially in the processes of migration/invasion and tube formation. In addition, CL2 would be a powerful tool for the pharmacological study of the mechanisms of the Sph-1-P/S1P(1) pathway in rheumatoid arthritis, diabetes retinopathy, and solid tumor growth processes.

Amino acid transporter ATA2 is stored at the trans-Golgi network and released by insulin stimulus in adipocytes.

Recently, we cloned the ATA/SNAT transporters responsible for amino acid transport system A. System A is one of the major transport systems for small neutral and glucogenic amino acids represented by alanine and is involved in the metabolism of glucose and fat. Here, we describe the cellular mechanisms that participate in the acute translocation of ATA2 by insulin stimulus in 3T3-L1 adipocytes. We monitored this insulin-stimulated translocation of ATA2 using an expression system of enhanced green fluorescent protein-tagged ATA2. Studies in living cells revealed that ATA2 is stored in a discrete perinuclear site and that the transporter is released in vesicles from this site toward the plasma membrane. In immunofluorescent analysis, the storage site of ATA2 overlapped with the location of syntaxin 6, a marker of the trans-Golgi network (TGN), but not with that of EEA1, a marker of the early endosomes. The ATA2-containing vesicles on or near the plasma membrane were distinct from GLUT4-containing vesicles. Brefeldin A, an inhibitor of vesicular exit from the TGN, caused morphological changes in the ATA2 storage site along with the similar changes in the TGN. In non-transfected adipocytes, brefeldin A inhibited insulin-stimulated uptake of alpha-(methylamino)isobutyric acid more profoundly than insulin-stimulated uptake of 2-deoxy-d-glucose. These data demonstrate that the ATA2 storage site is specifically associated with the TGN and not with the general endosomal recycling system. Thus, the insulin-stimulated translocation pathways for ATA2 and GLUT4 in adipocytes are distinct, involving different storage sites.

TTLL7 is a mammalian beta-tubulin polyglutamylase required for growth of MAP2-positive neurites.

Microtubules form a cytoskeletal framework that influences cell shape and provides structural support for the cell. Microtubules in the nervous system undergo a unique post-translational modification, polyglutamylation of the C termini of their tubulin subunits. The mammalian enzymes that perform beta-tubulin polyglutamylation as well as their physiological functions in the neuronal tissue remain elusive. We report identification of a mammalian polyglutamylase with specificity for beta-tubulin as well as its distribution and function in neurite growth. To identify putative tubulin polyglutamylases, we searched tubulin tyrosine ligase-like (TTLL) proteins for those predominantly expressed in the nervous system. Of 13 TTLL proteins, TTLL7 was transcribed at the highest level in the nervous system. Recombinant TTLL7 catalyzed tubulin polyglutamylation with high preference to beta-tubulin in vitro. When expressed in HEK293T cells, TTLL7 demonstrated specificity for beta-tubulin and not for alpha-tubulin or nucleosome assembly protein 1. Consistent with these findings, knockdown of TTLL7 in a primary culture of superior cervical ganglion neurons caused a loss of polyglutamylated beta-tubulin. Following stimulation of PC12 cells with nerve growth factor to differentiate, the level of TTLL7 increased concomitantly with polyglutamylation of beta-tubulin. Short interference RNA-mediated knockdown of TTLL7 repressed nerve growth factor-stimulated MAP (microtubule-associated protein) 2-positive neurite growth in PC12 cells. Consistent with having a role in the growth of MAP2-positive neurites, TTLL7 accumulated within a MAP2-enriched somatodendritic portion of superior cervical ganglion, as did polyglutamylated beta-tubulin. Anti-TTLL7 antibody revealed that TTLL7 was distributed in a somatodendritic compartment in the mouse brain. These findings indicate that TTLL7 is a beta-tubulin polyglutamylase and is required for the growth of MAP2-positive neurites in PC12 cells.

R-130823, a novel inhibitor of p38 MAPK, ameliorates hyperalgesia and swelling in arthritis models.

We found that a novel compound, R-130823 {2-(4-fluorophenyl)-4-(1-phenethyl-1,2,3,6-tetrahydropyridin-4-yl)-3-(pyridin-4-yl)-1H-pyrrole}, had highly selective inhibition against mitogen-activated protein kinase p38alpha (IC50=22 nM). The release of tumor necrosis factor-alpha, interleukin-1beta, -6 and -8 was inhibited in lipopolysaccharide-stimulated human blood pretreated by R-130823, with IC50 values of 0.089, 0.066, 0.95 and 0.16 microM, respectively. R-130823 reduced the established hind paw swelling in rat adjuvant-induced arthritis, while methotrexate showed no suppression. In the same model, R-130823 ameliorated adjuvant-induced hyperalgesia with rapid onset and long duration comparable to a cyclooxygenase-2 inhibitor, celecoxib. In murine collagen-induced arthritis, R-130823 blocked the progress of arthritis when administered just after the onset of the arthritis. Histological analysis of the knee joints showed that proliferation of fibroblasts and synoviocytes and infiltration of neutrophils were ameliorated. In conclusion, R-130823 is expected to be an efficacious treatment for rheumatoid arthritis by blocking the p38 pathway.