Cylindromas are benign adnexal skin tumors caused by germline mutations in the CYLD gene. In most cases the second wild-type allele is lost in tumor tissue, suggesting that CYLD functions as tumor suppressor. CYLD is a protein of 956 amino acids harboring a functional deubiquitinating domain at the COOH-terminal end. To shed more light on the function of CYLD, we have performed a yeast two hybrid screen using an HaCaT cDNA library that identified the RING finger protein TRIP (TRAF-interacting protein) as interactor with full-length CYLD. Mapping of the interacting domains revealed that the central domain of CYLD binds to the COOH-terminal end of TRIP. Far Western analysis and coimmunoprecipitations in mammalian cells confirmed that full-length CYLD binds to the COOH-terminal domain of TRIP. Because TRIP is an inhibitor of nuclear factor (NF)-κB activation by tumor necrosis factor (TNF), the effect of CYLD on NF-κB activation was investigated in HeLa cells. The results established that CYLD down-regulates NF-κB activation by TNF-α. The inhibition by CYLD depends on the presence of the central domain interacting with TRIP and its deubiquitinating activity. These findings indicate that cylindromas arise through constitutive NF-κB activation leading to hyperproliferation and tumor growth.

Rationale: CD146, a transmembrane immunoglobulin mainly expressed at the intercellular junction of endothelial cells, is involved in cell-cell cohesion, paracellular permeability, monocyte transmigration and angiogenesis. CD146 exists as 2 isoforms, short (sh) and long (lg), but which isoform is involved remains undefined. Objective: The recently described role of CD146 in angiogenesis prompted us to investigate which isoform was involved in this process in human late endothelial progenitors (EPCs), with the objective of increasing their proangiogenic potential. Methods and Results: Immunofluorescence experiments showed that, in subconfluent EPCs, shCD146 was localized in the nucleus and at the migrating edges of the membrane, whereas lgCD146 was intracellular. In confluent cells, shCD146 was redistributed at the apical membrane and lgCD146 was directed toward the junction. In contrast to lgCD146, shCD146 was overexpressed in EPCs as compared to mature endothelial cells and upregulated by vascular endothelial growth factor and SDF-1 (stromal cell-derived factor 1). Study of the properties of both isoforms in vitro provided evidence that shCD146 was involved in EPC adhesion to activated endothelium, migration, and proliferation, with a paracrine secretion of interleukin-8 or angiopoietin 2, whereas lgCD146 was implicated in stabilization of capillary-like structures in Matrigel and transendothelial permeability. In an animal model of hindlimb ischemia, transplantation of shCD146-modified EPCs selectively promoted both EPC engraftment and blood flow. Conclusions: Altogether, these findings establish that CD146 isoforms display distinct functions in vessels regeneration.Selective improvement of therapeutic angiogenesis by shCD146 overexpression suggests a potential interest of shCD146-transduced EPCs for the treatment of peripheral ischemic disease. (Circ Res. 2010;107:66-75.)Key Words: CD146 Ⅲ endothelial progenitor Ⅲ angiogenesis Ⅲ ischemia Ⅲ peripheral artery disease C D146 is a cell adhesion molecule belonging to the immunoglobulin superfamily. It has been described as a component of the endothelial junction involved in the control of cell cohesion, permeability, and monocyte transmigration. 1,2 Initially described as a marker of tumor growth and metastasis in human melanoma, 3 CD146 has recently been shown to be involved in angiogenesis. Thus, it was reported that anti-CD146 antibodies inhibited proliferation and migration of HUVECs, 4 and also inhibited angiogenesis in chicken chorioallantoic membrane assays and tumor growth in mice. 5 Two different isoforms of gicerin, the chicken homolog of CD146, have been described by Dunon and colleagues.These 2 isoforms are generated by alternative splicing and differ at the end of their cytoplasmic region. 6 -8 The short isoform of gicerin exhibits a putative PDZ binding domain, which could mediate its anchoring to the cytoskeleton, whereas the long isoform contains a putative endocytosis motif. 6 Recently it was shown that, under shear stress conditions, transfection...

Bioassay-guided fractionation, combined with screening based on EGF-responsive neural stem cells (NSCs) differentiation assay, has been used to search for active molecules from Panax notoginseng. Ginsenosides Rg3 (1), Rk1 (2), and Rg5 (3) were identified as potential neurogenic molecules. The degrees of their neurogenic effects were found to be 3 > 2 > 1. The neurogenic effect of 3 represents a biphasic dose- and time-dependent regulation. Transient exposure of NSCs to 8 microM 3 for 24 h followed by 1 microM and 72 h incubation was the optimal procedure for the induction of neurons in NSCs, and compound 3 resulted in an approximately 3-fold increase in neurogenesis at the expense of astrogliogenesis. The neurogenic effect of 3 was completely eliminated by the Ca2+ channel antagonist nifedipine. These findings imply that 3 may be utilized as a pharmacological agent in studying the molecular regulation of neurogenesis of brain stem cells and, subsequently, for treatment of neurodegenerative diseases.

BackgroundToll-like receptors (TLR) recognize pathogen-associated molecular patterns and are important mediators of the innate immune system. TLR1 and TLR6 are paralogs and located in tandem on the same chromosome in mammals. They form heterodimers with TLR2 and bind lipopeptide components of gram-positive and gram-negative bacterial cell walls. To identify conserved stretches in TLR1 and TLR6, that may be important for their function, we compared their protein sequences in nine mammalian species(Homo sapiens, Pan troglodytes, Macaca mulatta, Mus musculus, Rattus norvegicus; Erinaceus europaeus, Bos Taurus, Sus scrofa and Canis familiaris).ResultsThe N-terminal sequences of the orthologous proteins showed greater similarity than corresponding paralog sequences. However, we identified a region of 300 amino acids towards the C-terminus of TLR1 and TLR6, where paralogs had a greater degree of sequence identity than orthologs. Preservation of DNA sequence identity of paralogs in this region was observed in all nine mammalian species investigated, and is due to independent gene conversion events. The regions having undergone gene conversion in each species are almost identical and encode the leucine-rich repeat motifs 16 to 19, the C-terminal cap motif, the transmembrane domain and most of the intracellular Toll/interleukin-1 receptor (TIR) domain.ConclusionOur results show that, for a specific conserved region, divergence of TLR1 and TLR6 is limited by gene conversion, most likely because of the need for co-evolution with multiple intracellular and extracellular binding partners. Thus, gene conversion provides a mechanism for limiting the divergence of functional regions of protein paralogs, while allowing other domains to evolve diversified functions.

ObjectiveTo analyze the expression of macrophages, AIM, TGF-β1 in the kidney of IgAN patients, and to explore the role of macrophages, AIM, TGF-β1 in the progression of renal fibrosis in IgAN patients.MethodsThe paraffin specimens of renal tissue from 40 IgAN patients were selected as the observation group. At the same time, paraffin specimens of normal renal tissue from 11 patients treated by nephrectomy were selected as the normal control group. We observed the distribution of macrophages, the expression of AIM and TGF-β1 by immunohistochemical staining and/or immunofluorescence.ResultThe number of M0, M1, M2 macrophages could be found increased in IgAN patients. M0 macrophages are mainly polarized towards M2 macrophages. The expression of AIM and TGF-β1 were significantly higher in IgAN patients than in NC. M2 macrophage, AIM and TGF-β1 were positively correlated with serum creatinine and 24-hour proteinuria, but negatively correlated with eGFR. M2 macrophages, AIM, TGF-β1 were positively correlated with fibrotic area.ConclusionM2 macrophages, AIM and TGF-β1 play important roles in the process of IgAN fibrosis, and the three influence each other.