The transcription factor NFB is activated by phosphorylation and acetylation and plays important roles in inflammatory and immune responses in the cell. Additionally, posttranslational modification of the NFB p65 subunit by O-linked N-acetylglucosamine (OGlcNAc) has been reported, but the modification site of O-GlcNAc on NFB p65 and its exact function have not been elucidated. In this work, we show that O-GlcNAcylation of NFB p65 decreases binding to IB␣ and increases transcriptional activity under hyperglycemic conditions. Also, we demonstrate that both Thr-322 and Thr-352 of NFB p65 can be modified with O-GlcNAc, but modification on Thr-352, not Thr-322, is important for transcriptional activation. Our findings suggest that site-specific O-GlcNAcylation may be a reason why NFB activity increases continuously under hyperglycemic conditions.T ranscription factor NFB plays important roles in inflammatory, immune, and antiapoptotic responses (1-3). In mammals, NFB is present as a dimer composed of various combinations of Rel proteins such as p65 (RelA), RelB, c-Rel, p50/p105, and p52/p100. In most cell types, NFB is composed of p65 and p50 and is localized in the cytosol where it binds inhibitor (IB). Treatment with NFB-activating agents such as tumor necrosis factor ␣ (TNF␣) activates IB kinase (IKK) complexes, inducing phosphorylation in the N terminus of IB. The phosphorylation event induces IB degradation via a ubiquitin-dependent proteolysis. Free NFB translocates to the nucleus and activates the expression of target genes (1, 2).Posttranslational modifications such as phosphorylation (4-9) and acetylation (10, 11) regulate the transcriptional activity of NFB. The activity of NFB is influenced also by the hexosamine biosynthetic pathway, which produces a substrate of O-GlcNAcylation, UDP-GlcNAc (12). Many nucleocytoplasmic proteins are known to be dynamically modified with O-GlcNAc. This modification is modulated by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) (13-18). O-GlcNAcylation levels play an important role in transcription, translation, nuclear transport, protein stability, and protein-protein interactions and can be increased under hyperglycemic conditions caused by diabetes (16 -18). Although it is known that O-GlcNAcylation of NFB is involved in hyperglycemia-induced NFB activation (12) and is required for lymphocyte activation (19), the specific sites and the function of O-GlcNAcylation on NFB are not well understood.In this work, we show that OGA overexpression downregulates O-GlcNAcylation and inhibits hyperglycemia-induced NFB activation in rat vascular smooth muscle cells (VSMCs). In contrast, up-regulation of O-GlcNAcylation after OGT overexpression and treatment of cells with the O-GlcNAcase inhibitors streptozotocin (STZ) (20) and O-(2-acetamido-2-deoxy-Dglucopyranosylidene)amino-N-phenylcarbamate (PUGNAc)(21) increase NFB transcriptional activity. Additionally, we identify Thr-322 and Thr-352 as O-GlcNAcylation sites in a mutation study and with mass spectrometry analysis. Our data sho...

Mannosylations of various acceptors with donors possessing an electron-withdrawing o-trifluoromethylbenzenesulfonyl, benzylsulfonyl, p-nitrobenzoyl, benzoyl, or acetyl group at O-3, O-4, or O-6 positions were found to be beta-selective except when donors had 3-O-acyl and 6-O-acetyl groups, which afforded alpha-mannosides as major products. The alpha-directing effect of 3-O-acyl and 6-O-acetyl groups was attributed to their remote participation, and the isolation of a stable bicyclic trichlorooxazine ring resulting from the intramolecular trapping of the anomeric oxocarbenium ion by 3-O-trichloroacetimidoyl group provided evidence for this remote participation. The triflate anion, counteranion of the mannosyl oxocarbenium ion, was essential for the beta-selectivity, and covalent alpha-mannosyl triflates with an electron-withdrawing group at O-3, O-4, or O-6 were detected by low-temperature NMR. The strongly electron-withdrawing sulfonyl groups, which exhibited a higher beta-directing effect in the mannosylation, made the alpha-mannosyl triflates more stable than the weakly electron-withdrawing acyl groups. We therefore proposed the mechanism for the beta-mannosylation and the origin of the beta-directing effect: the electron-withdrawing groups would stabilize the alpha-mannosyl triflate intermediate, and the subsequent reaction of the alpha-triflate (or its contact ion pair) with the acceptor would afford the beta-mannoside. The beta-selective mannosylation of a sterically demanding acceptor was achieved by employing a donor possessing two strongly electron-withdrawing benzylsulfonyl groups at O-4 and O-6 positions.

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BackgroundWe wanted to investigate the results of surgical treatment and analyze the factors that have an influence on the neurologic symptoms and prognosis of spinal intradural extramedullary (IDEM) tumors.MethodsThe spinal IDEM tumor patients (11 cases) who had been treated by surgical excision and who were followed up more than 1 year were retrospectively analyzed. Pain was evaluated by the visual analogue scale (VAS) and the neurologic function was assessed by Nurick's grade. The pathological diagnosis, the preoperative symptom duration, the tumor location on the sagittal and axial planes and the percentage of tumor occupying the intradural space were investigated. In addition, all these factors were analyzed in relation to the degree of the preoperative symptoms and the prognosis. On the last follow-up, the MRI was checked to evaluate whether or not the tumor had recurred.ResultsThe most common diagnosis was schwannomas (73%), followed by meningiomas (18%). The percentage of tumor occupying the intradural space was 82.9 ± 9.4%. The VAS score was reduced in all cases from 8.0 ± 1.2 to 1.2 ± 0.8 (p = 0.003) and the Nurick's grade was improved in all cases from 3.0 ± 1.3 to 1.0 ± 0.0 (p = 0.005). The preoperative symptoms were correlated with only the percentage of tumor occupying the intradural space (VAS; r2 = 0.75, p = 0.010, Nurick's grade; r2 = 0.69, p = 0.019). One case of schwannoma recurred.ConclusionsThe degree of neurologic symptoms was correlated with the percentage of tumor occupying the intradural space. All the tumors were able to be excised through the posterior approach. The postoperative neurologic recovery was excellent in all the cases regardless of any condition. Therefore, aggressive surgical excision is recommended even for cases with a long duration of symptoms or a severe neurologic deficit.