Search results for "Up-Regulation"
showing 10 items of 455 documents
Requirement of Retinoic Acid Receptor Isotypes α, β, and γ during the Initial Steps of Neural Differentiation of PCC7 Cells
2005
Retinoic acid (RA) is indispensable for morphogenesis and differentiation of several tissues, including the nervous system. The requirement of the RA receptor (RAR) isotypes alpha, beta, and gamma and the putative role of retinoid X receptor-(RXR) signaling in RA-induced neural differentiation, was analyzed. For this compound-selective retinoids and the murine embryonal carcinoma cell line PCC7, a model system for RA-dependent neural differentiation was used. The present paper shows that proliferating PCC7 cells primarily express RXRalpha and RARalpha, lower levels of RXRbeta, and barely detectable amounts of RARbeta, RARgamma, and RXRgamma. At receptor-selective concentrations, only a RARa…
Protection from lethal septic peritonitis by neutralizing the biological function of interleukin 27
2006
The immune response to bacterial infections must be tightly controlled to guarantee pathogen elimination while preventing tissue damage by uncontrolled inflammation. Here, we demonstrate a key role of interleukin (IL)-27 in regulating this critical balance. IL-27 was rapidly induced during murine experimental peritonitis induced by cecal ligation and puncture (CLP). Furthermore, mice deficient for the EBI3 subunit of IL-27 were resistant to CLP-induced septic peritonitis as compared with wild-type controls, and this effect could be suppressed by injection of recombinant single-chain IL-27. EBI3−/− mice displayed significantly enhanced neutrophil migration and oxidative burst capacity during…
Stimulation of protein (collagen) synthesis in sponge cells by a cardiac myotrophin‐related molecule from Suberites domuncula
2000
The body wall of sponges (Porifera), the lowest metazoan phylum, is formed by two epithelial cell layers of exopinacocytes and endopinacocytes, both of which are associated with collagen fibrils. Here we show that a myotrophin-like polypeptide from the sponge Suberites domuncula causes the expression of collagen in cells from the same sponge in vitro. The cDNA of the sponge myotrophin was isolated; the potential open reading frame of 360 nt encodes a 120 aa long protein (Mr of 12,837). The sequence SUBDOMYOL shares high similarity with the known metazoan myotrophin sequences. The expression of SUBDOMYOL is low in single cells but high after formation of primmorph aggregates as well as in in…
A new vicious cycle involving glutamate excitotoxicity, oxidative stress and mitochondrial dynamics
2011
Glutamate excitotoxicity leads to fragmented mitochondria in neurodegenerative diseases, mediated by nitric oxide and S-nitrosylation of dynamin-related protein 1, a mitochondrial outer membrane fission protein. Optic atrophy gene 1 (OPA1) is an inner membrane protein important for mitochondrial fusion. Autosomal dominant optic atrophy (ADOA), caused by mutations in OPA1, is a neurodegenerative disease affecting mainly retinal ganglion cells (RGCs). Here, we showed that OPA1 deficiency in an ADOA model influences N-methyl-D-aspartate (NMDA) receptor expression, which is involved in glutamate excitotoxicity and oxidative stress. Opa1enu/+mice show a slow progressive loss of RGCs, activation …
Centenarians maintain miRNA biogenesis pathway while it is impaired in octogenarians.
2016
Centenarians but not octogenarians up regulate the expression of miRNAs, as we previously reported. We have looked into miRNA biogenesis. We show that RNA POL II, DROSHA, EXPORTIN 5 and DICER, are up-regulated in centenarians compared with octogenarians. Furthermore, factors involved in the control of these miRNAs biogenesis genes are also up-regulated in centenarians. Therefore, the up-regulation of miRNA expression in centenarians can be explained in part because miRNA biogenesis pathway is depressed in octogenarians (ordinary aging) while it is maintained in centenarians (extraordinary aging).
MiR-29b antagonizes the pro-inflammatory tumor-promoting activity of multiple myeloma-educated dendritic cells
2017
Dendritic cells (DCs) have a key role in regulating tumor immunity, tumor cell growth and drug resistance. We hypothesized that multiple myeloma (MM) cells might recruit and reprogram DCs to a tumor-permissive phenotype by changes within their microRNA (miRNA) network. By analyzing six different miRNA-profiling data sets, miR-29b was identified as the only miRNA upregulated in normal mature DCs and significantly downregulated in tumor-associated DCs. This finding was validated in primary DCs co-cultured in vitro with MM cell lines and in primary bone marrow DCs from MM patients. In DCs co-cultured with MM cells, enforced expression of miR-29b counteracted pro-inflammatory pathways, includin…
Rtp1p Is a Karyopherin-Like Protein Required for RNA Polymerase II Biogenesis
2013
The assembly and nuclear transport of RNA polymerase II (RNA pol II) are processes that require the participation of many auxiliary factors. In a yeast genetic screen, we identified a previously uncharacterized gene, YMR185w (renamed RTP1), which encodes a protein required for the nuclear import of RNA pol II. Using protein affinity purification coupled to mass spectrometry, we identified interactions between Rtp1p and members of the R2TP complex. Rtp1p also interacts, to a different extent, with several RNA pol II subunits. The pattern of interactions is compatible with a role for Rtp1p as an assembly factor that participates in the formation of the Rpb2/Rpb3 subassembly complex and its bi…
Response of the Saccharomyces cerevisiae Mpk1 Mitogen-Activated Protein Kinase Pathway to Increases in Internal Turgor Pressure Caused by Loss of Ppz…
2004
ABSTRACT The Mpk1 pathway of Saccharomyces cerevisiae is a key determinant of cell wall integrity. A genetic link between the Mpk1 kinase and the Ppz phosphatases has been reported, but the nature of this connection was unclear. Recently, the Ppz phosphatases were shown to be regulators of K + and pH homeostasis. Here, we demonstrate that Ppz-deficient strains display increased steady-state K + levels and sensitivity to increased KCl concentrations. Given these observations and the fact that K + is the major determinant of intracellular turgor pressure, we reasoned that the connection between PPZ1 and - 2 and MPK1 was due to the combination of increased internal turgor pressure in Ppz-defic…
Saccharomyces cerevisiae Glutaredoxin 5-deficient Cells Subjected to Continuous Oxidizing Conditions Are Affected in the Expression of Specific Sets …
2004
The Saccharomyces cerevisiae GRX5 gene codes for a mitochondrial glutaredoxin involved in the synthesis of iron/sulfur clusters. Its absence prevents respiratory growth and causes the accumulation of iron inside cells and constitutive oxidation of proteins. Null ⌬grx5 mu- tants were used as an example of continuously oxidized cells, as opposed to situations in which oxidative stress is instantaneously caused by addition of external oxi- dants. Whole transcriptome analysis was carried out in the mutant cells. The set of genes whose expression was affected by the absence of Grx5 does not significantly overlap with the set of genes affected in respiratory petite mutants. Many Aft1-dependent ge…
Characterization of aging-associated up-regulation of constitutive nuclear factor-kappa B binding activity.
2001
Changes occur in gene expression during aging in vivo and in replicative senescence in vitro, suggesting that aging can affect gene regulation. We have recently observed age-related changes in ubiquitously expressed, oxidative stress-responsive nuclear factor-kappa B (NF-kappa B) pathway during aging. Here we report a significant age-related increase in nuclear NF-kappa B binding activity together with increased protein levels of p52 and p65 components in rat liver. An additional, higher molecular weight protein band seen in their western blots suggests that their post-translational modification (but not phosphorylation) occurs in liver, which might affect their nuclear localization and bin…