No abstract

CD40 signalings play crucial roles in B-cell function.To identify molecules which transduce CD40 signalings, we have utilized the yeast two-hybrid system to clone cDNAs encoding proteins that bind the cytoplasmic tail of CD40. A cDNA encoding a putative signal transducer, designated TRAF6, has been molecularly cloned. TRAF6 has a tumor necrosis factor receptor (TNFR)-associated factor (TRAF) domain in its carboxyl terminus and has a RING finger domain, a cluster of zinc fingers and a coiled-coil domain, which are also present in other TRAF family proteins. TRAF6 does not associate with the cytoplasmic tails of TNFR2, CD30, lymphotoxin-␤ receptor, and LMP1 of Epstein-Barr virus. Deletion analysis showed that residues 246 -269 of CD40 which are required for its association with TRAF2, TRAF3, and TRAF5 are dispensable for its interaction with TRAF6, whereas residues 230 -245 were required. Overexpression of TRAF6 activates transcription factor NFB, and its TRAF-C domain suppresses NFB activation triggered by CD40 lacking residues 246 -277. These results suggest that TRAF6 could mediate the CD40 signal that is transduced by the amino-terminal domain (230 -245) of the CD40 cytoplasmic region and appears to be independent of other known TRAF family proteins.

Three cDNAs for the human granulocyte colony-stimulating factor (G-CSF) receptor were isolated from the cDNA libraries of human U937 leukemia cells and placenta by using a murine G-CSF receptor cDNA as the probe. The human G-CSF receptor containing 813 amino acids had a marked homology (62.5%) with its murine counterpart and consisted of extracellular, transmembrane, and cytoplasmic domains. The WSXWS motif found in members of the newly identified growth factor receptor family was also present in the extracellular domain of the human G-CSF receptor.

We attempted to identify the factor that stimulated prostacyclin (PGI2) production using conditioned medium from cultured human diploid fibroblast cells subjected to a series of purification steps using h.p.l.c. on DEAE-5PW, Heparin-5PW, Protein-Pak 300, and an insulin-like growth factor-1 ligand affinity column. The purified prostacyclin-stimulating factor (PSF) ran as a single band with a molecular mass of 31 kDa by SDS/PAGE. Analysis of the purified PSF by C4 reversed-phase h.p.l.c. showed a single sharp peak in 31% (v/v) acetonitrile. The material was purified 8000-fold with an overall yield of about 18%. The purified PSF stimulated PGI2 production by cultured bovine aortic endothelial cells at a concentration of about 10 ng/ml; maximal stimulation was achieved at a concentration of 25 ng/ml. A cDNA coding for PSF was cloned and sequenced, revealing an apparently novel protein with no obvious sequence similarity to known proteins.

Background/AimsThis study compared the efficacy of multimatrix mesalazine 2.4 g/day and 4.8 g/day with controlled-release mesalazine 2.25 g/day.MethodsIn this multicenter, randomized, double-blind study, 251 patients with mildly to moderately active ulcerative colitis received multimatrix mesalazine 2.4 g/day once daily (Multimatrix-2.4), 4.8 g/day once daily (Multimatrix-4.8), or controlled-release (time-dependent) mesalazine 2.25 g/day 3 times daily (Time-2.25) for 8 weeks. The primary efficacy endpoint was the change in the ulcerative colitis-disease activity index (UC-DAI) score.ResultsThe mean change in the UC-DAI score and standard deviation in the per protocol set was −1.9±2.5 for Multimatrix-2.4 and −2.4±2.8 for Time-2.25. The difference between Multimatrix-2.4 and Time-2.25 was 0.3 (two-sided 95% confidence interval [CI], −0.5 to 1.1), thus non-inferiority was not demonstrated based on the pre-defined non-inferiority margin (1.0). In the full analysis set, the difference between Multimatrix-4.8 and Time-2.25 was −1.2 (two-sided 95% CI, −2.0 to −0.5), and the mean change in UC-DAI score in the FAS was −3.3 (two-sided 95% CI, −3.9 to −2.8) for Multimatrix-4.8 and −1.9 (two-sided 95% CI, −2.5 to −1.3) for Multimatrix-2.4, indicating that Multimatrix-4.8 was more effective than Time-2.25 and Multimatrix-2.4. There was no difference among the treatment groups in terms of safety.ConclusionsThis study showed that the efficacy of multimatrix mesalazine 2.4 g/day was comparable to controlled release mesalazine 2.25 g/day, although non-inferiority was not demonstrated. Importantly, this was the first study to indicate that multimatrix mesalazine 4.8 g/day was more effective than 2.4g/day with no associated safety concerns.