The Notch signaling pathway appears to perform an important function in a wide variety of organisms and cell types. In our present study, we provide evidence that UV irradiation-induced Tip60 proteins reduced Notch1 activity to a marked degree. Accumulated UV irradiation-induced Tip60 suppresses Notch1 transcriptional activity via the dissociation of the Notch1-IC-CSL complex.
View Article and Find Full Text PDFDried roots of the plants Acanthopanax senticosus, Angelica sinensis and Scutellaria baicalensis are used in traditional oriental medicine and reportedly possess anti-inflammatory properties. Using the murine air pouch model of inflammation, we investigated the efficacy and mode of action of an extract from these three plants in crystal-induced inflammation. Air pouches were raised on the backs of 8-week-old BALB/c mice.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2007
Site-directed spin labeling (SDSL) was used to examine and compare transmembrane signaling events in the bacterial outer-membrane transport proteins BtuB, FecA, and FhuA. These proteins extract energy for transport by coupling to the transperiplasmic protein TonB, an interaction that is thought to be mediated by the Ton box, a highly conserved energy-coupling motif in these transporters. In the ferric citrate transporter, FecA, SDSL indicates that the Ton box undergoes a substrate-induced disorder transition similar to that seen for BtuB, the vitamin B(12) transporter.
View Article and Find Full Text PDFIntegrin-linked kinase (ILK) is a scaffold and protein kinase that acts as a pivotal effector in integrin signaling for various cellular functions. In this study, we found that ILK remarkably reduced the protein stability of Notch1 through Fbw7. The kinase activity of ILK was essential for the inhibition of Notch1 signaling.
View Article and Find Full Text PDFThe Notch signaling pathway appears to perform an important function in the determination of cell fate and in differentiation, in a wide variety of organisms and cell types. In this study, we provide evidence that the inactivation of Notch signaling by zinc is achieved via a PI3K-Akt-dependent, cytoplasmic retention of Notch1-IC and RBP-Jk. Extracellular zinc has been determined to inhibit constitutive active mutants of both Notch1 (DeltaEN1) and Notch1-IC-mediated transcription.
View Article and Find Full Text PDFAire-expressing medullary thymic epithelial cells (mTECs) play a key role in preventing autoimmunity by expressing tissue-restricted antigens to help purge the emerging T cell receptor repertoire of self-reactive specificities. Here we demonstrate a novel role for a CD4(+)3(-) inducer cell population, previously linked to development of organized secondary lymphoid structures and maintenance of T cell memory in the functional regulation of Aire-mediated promiscuous gene expression in the thymus. CD4(+)3(-) cells are closely associated with mTECs in adult thymus, and in fetal thymus their appearance is temporally linked with the appearance of Aire(+) mTECs.
View Article and Find Full Text PDFThe amyloid beta-precursor protein (APP) and the Notch receptor are both type 1 integral transmembrane proteins, and both are cleaved by presenilin-dependent gamma-secretase activity. In this study, we have demonstrated that the Notch intracellular domain (Notch1-IC) suppresses APP-intracellular domain (AICD)-mediated ROS generation and cell death after being processed by gamma secretase. Notch1-IC physically interacts with AICD, Fe65, and Tip60, thereby disrupting the association of the AICD-Fe65-Tip60 trimeric transcription activator complex in AICD signaling.
View Article and Find Full Text PDFSensitive to apoptosis gene (SAG), a novel zinc RING finger protein, exhibits anti-apoptotic and antioxidant activity against a variety of redox reagents. In the present study, we have determined that SAG suppresses 1-methyl-4-phenylpyridinium ion (MPP(+))-induced neurotoxicity via the downregulation of ROS generation and c-Jun N-terminal kinase 1 (JNK1) activity. Both transient and constitutively overexpressed SAG were found to inhibit the MPP(+)-induced neurotoxicity of SH-SY5Y neuroblastoma cells.
View Article and Find Full Text PDFSubcutaneous panniculitis-like T-cell lymphoma is a rare cytotoxic T-cell lymphoma of the skin that preferentially infiltrates the subcutaneous tissue. We report here this lymphoma occurring in a 26-month-old Korean girl. She presented with multiple erythematous subcutaneous nodules on both extremities and her back along with systemic symptoms.
View Article and Find Full Text PDFBackground: Autologous split-thickness skin grafts (STSGs) are considered the mainstay for the treatment of large full-thickness wounds. There have been few studies reporting the natural change of the skin function in STSGs after procedure, however.
Objective: The objective was to evaluate the natural change of the skin function in STSG using noninvasive bioengineering methods.
Lymphocytes from lymphotoxin (LT) alpha-deficient mice, which lack segregation of their B- and T-cell areas, acquire normal organization following adoptive transfer into RAG-deficient recipients, identifying a non-B non-T cell in the segregation process. Here we show that a CD4+CD3- accessory cell is tightly associated with discrete VCAM-1-expressing stromal cells in B- and T-cell areas of the mouse spleen. CD4+CD3- cells express high levels of LTalpha, LTbeta, and tumor necrosis factor (TNF) alpha, which are the ligands for the LTbeta receptor and TNFR1 expressed by stromal cells.
View Article and Find Full Text PDFBtuB is a TonB-dependent transport protein that binds and carries vitamin B(12) across the outer membrane of Gram negative bacteria such as Escherichia coli. Previous work has demonstrated that the Ton box, a highly conserved segment near the N-terminus of the protein, undergoes an order-to-disorder transition upon the binding of substrate. Here, we incorporate pairs of nitroxide spin labels into membrane reconstituted BtuB and utilize a four-pulse double electron-electron resonance (DEER) experiment to measure distances between the Ton box and the periplasmic surface of the transporter with and without substrate.
View Article and Find Full Text PDFWe report here the quantitative expression of a set of immunity-related genes, including TNF family members, chemokine receptors, and transcription factors, in a CD4+ CD3- accessory cell. By correlating gene expression between cell-sorted populations of defined phenotype, we show that the genetic fingerprint of these CD4+ CD3- cells is distinct from dendritic cells, plasmacytoid dendritic cells, T cells, B cells, and NK cells. In contrast, it is highly similar to CD4+ CD3- cells isolated from embryonic and neonatal tissues, with the exception that only adult populations express OX40L and CD30L.
View Article and Find Full Text PDFThe flower buds of Buddleja officinalis MAXIM (Loganiaceae) are used to treat headache and inflammatory diseases in traditional Korean medicine. In the present study, the neuroprotective effects of the methanolic extract of B. officinalis (BOME) and of its hexane fraction (BOHF) were investigated in a middle cerebral artery occlusion (MCAo, 120 min occlusion, 24 h reperfusion) Sprague-Dawley rat model.
View Article and Find Full Text PDFSmall crimson fruit of Viburnum dilatatum Thunb. (gamazumi), a wild deciduous low tree belonging to a family of Caprifoliaceae, has strong antioxidant activity, and cyanidin 3-sambubioside (C3S) and 5-caffeoyl quinic acid (5-CQA) are identified as active compounds. The freeze-dried powder of V.
View Article and Find Full Text PDFIn this report, we show that the formation of germinal center (GC)-like structures to thymus-independent type 2 antigens in mice depends on intact signals through CD40, but does not depend on T cell-derived CD40-ligand (CD154). In addition, we show that follicular dendritic cells (FDC) are also critical to thymus-independent GC formation, as their depletion by blockade of lymphotoxin-beta receptor signals abrogated GC development unless the responding B cells bound antigen with high affinity. Further evidence that immune complexes drove this CD40-dependent B cell proliferation was provided by the observation that an antibody that detects immune complexes containing complement component 4 on FDC also inhibited thymus-independent GC formation when injected in vivo at the time of immunization.
View Article and Find Full Text PDFBackground: Melasma is a common cosmetic problem among Asians. While various treatments are currently being used, there is no entirely satisfactory treatment. It was recently reported that the topical plasmin inhibitor is an effective treatment for ultraviolet-induced hyperpigmentation.
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