Hypoxia-inducible factor 1 (HIF-1) is a basic helixloop-helix transcription factor which is expressed when mammalian cells are subjected to hypoxia and which activates transcription of genes encoding erythropoietin, vascular endothelial growth factor, and other proteins that are important for maintaining oxygen homeostasis. Previous studies have provided indirect evidence that HIF-1 also regulates transcription of genes encoding glycolytic enzymes. In this paper we characterize hypoxia response elements in the promoters of the ALDA, ENO1, and Ldha genes. We demonstrate that HIF-1 plays an essential role in activating transcription via these elements and show that although absolutely necessary, the presence of a HIF-1 binding site alone is not sufficient to mediate transcriptional responses to hypoxia. Analysis of hypoxia response elements in the ENO1 and Ldha gene promoters revealed that each contains two functionally-essential HIF-1 sites arranged as direct and inverted repeats, respectively. Our data establish that functional hypoxia-response elements consist of a pair of contiguous transcription factor binding sites at least one of which contains the core sequence 5-RCGTG-3 and is recognized by HIF-1. These results provide further evidence that the coordinate transcriptional activation of genes encoding glycolytic enzymes which occurs in hypoxic cells is mediated by HIF-1.Multiple homeostatic mechanisms are employed by mammals to respond to chronic hypoxia. In the case of systemic hypoxia due to decreased environmental O 2 (hypobaric hypoxia) or decreased blood O 2 -carrying capacity (anemia), erythropoiesis is stimulated by the production of erythropoietin (EPO).

The Myc promoter-binding protein-1 (MBP-

Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease with a very poor 5-year survival rate. a-Enolase is a glycolytic enzyme that also acts as a surface plasminogen receptor. We find that it is overexpressed in PDAC and present on the cell surface of PDAC cell lines. The clinical correlation of its expression with tumor status has been reported for lung and hepatocellular carcinoma. We have previously demonstrated that sera from PDAC patients contain IgG autoantibodies to a-enolase. The present work was intended to assess the ability of a-enolase to induce antigen-specific T cell responses. We show that a-enolase-pulsed dendritic cells (DC) specifically stimulate healthy autologous T cells to proliferate, secrete IFN-c and lyse PDAC cells but not normal cells. In vivo, a-enolase-specific T cells inhibited the growth of PDAC cells in immunodeficient mice. In 8 out of 12 PDAC patients with circulating IgG to a-enolase, the existence of a-enolase-specific T cells was also demonstrated. Taken as a whole, these results indicate that a-enolase elicits a PDAC-specific, integrated humoral and cellular response. It is thus a promising and clinically relevant molecular target candidate for immunotherapeutic approaches as new adjuvants to conventional treatments in pancreatic cancer. ' 2009 UICC

The human PVT-1 gene is located on chromosome 8 telomeric to the c-Myc gene and it is frequently involved in the translocations occurring in variant Burkitt's lymphomas and murine plasmacytomas. It has been proposed that PVT-1 regulates c-Myc gene transcription over a long distance. To get new insights into the functional relationships between the two genes, we have investigated PVT-1 and c-Myc expression in normal human tissues and in transformed cells. Our findings indicate that PVT-1 expression is restricted to a relative low number of normal tissues compared to the wide distribution of c-Myc mRNA, whereas the gene is highly expressed in many transformed cell types including neuroblastoma cells that do not express c-Myc. Reporter gene assays were used to dissect the PVT-1 promoter and to identify the region responsible for the elevated expression observed in transformed cells. This region contains two putative binding sites for Myc proteins. The results of transfection experiments in RAT1-MycER cells and chromatin immunoprecipitation (ChIP) assays in proliferating and differentiated neuroblastoma cells indicate that PVT-1 is a downstream target of Myc proteins.

Renal targets of autoimmunity in human lupus nephritis (LN) are unknown. We sought to identify autoantibodies and glomerular target antigens in renal biopsy samples from patients with LN and determine whether the same autoantibodies can be detected in circulation. Glomeruli were microdissected from biopsy samples of 20 patients with LN and characterized by proteomic techniques. Serum samples from large cohorts of patients with systemic lupus erythematosus (SLE) with and without LN and other glomerulonephritides were tested. Glomerular IgGs recognized 11 podocyte antigens, with reactivity varying by LN pathology. Notably, IgG2 autoantibodies against a-enolase and annexin AI were detected in 11 and 10 of the biopsy samples, respectively, and predominated over other autoantibodies. Immunohistochemistry revealed colocalization of a-enolase or annexin AI with IgG2 in glomeruli. High levels of serum anti-a-enolase (.15 mg/L) IgG2 and/or anti-annexin AI (.2.7 mg/L) IgG2 were detected in most patients with LN but not patients with other glomerulonephritides, and they identified two cohorts: patients with high anti-a-enolase/low anti-annexin AI IgG2 and patients with low anti-a-enolase/high anti-annexin AI IgG2. Serum levels of both autoantibodies decreased significantly after 12 months of therapy for LN. Anti-a-enolase IgG2 recognized specific epitopes of a-enolase and did not cross-react with dsDNA. Furthermore, nephritogenic monoclonal IgG2 (clone H147) derived from lupus-prone MRL-lpr/lpr mice recognized human a-enolase, suggesting homology between animal models and human LN. These data show a multiantibody composition in LN, where IgG2 autoantibodies against a-enolase and annexin AI predominate in the glomerulus and can be detected in serum.

We previously purified a 48-kDa protein (p48) that specifically reacts with an antiserum directed against the 12 carboxyl-terminal amino acids of the c-myc gene product. Using an antiserum directed against the purified p48, we have cloned a cDNA from a human expression library. This cDNA hybrid-selects an mRNA that translates to a 48-kDa protein that specifically reacts with anti-p48 serum. We have isolated a full-length cDNA that encodes p48 and spans 1755 bases. The coding region is 1299 bases long; 94 bases are 5' noncoding and 359 bases are 3' noncoding. The cDNA encodes a 433 amino acid protein that is 67% homologous to yeast enolase and 94% homologous to the rat non-neuronal enolase. The purified protein has been shown to have enolase activity and has been identified to be of the a type by isoenzyme analysis. The transcriptional regulation of enolase expression in response to mitogenic stimulation of peripheral blood lymphocytes and in response to heat shock is also discussed.We previously reported (1) the purification of a 48-kDa protein that crossreacts with an antiserum against a synthetic peptide corresponding to the carboxyl terminus of the human cellular myc protein (1). This protein was characterized as having a basic isoelectric point and cytoplasmic localization. The protein is present in a relatively high amount in all the cell types analyzed with the exception of normal resting lymphocytes, where it is detectable only after mitogenic stimulation (1). We now have used an antiserum prepared against purified p48 to screen a human cDNA expression library, and we have isolated a full-length cDNA coding for p48. The predicted amino acid sequence of p48 is 94% homologous to the amino acid sequence of rat non-neuronal enolase (2), identifying p48 as a subunit of human enolase.Enolase is a glycolytic enzyme (2-phospho-D-glycerate hydro-lyase, EC 4.2

We have previously identified a muscle-specific enhancer within the first intron of the human ␤ enolase gene. Present in this enhancer are an A/T-rich box that binds MEF-2 protein(s) and a G-rich box (AGTGGGG-GAGGGGGCTGCG) that interacts with ubiquitously expressed factors. Both elements are required for tissuespecific expression of the gene in skeletal muscle cells. Here, we report the identification and characterization of a Kruppel-like zinc finger protein, termed ␤ enolase repressor factor 1, that binds in a sequence-specific manner to the G-rich box and functions as a repressor of the ␤ enolase gene transcription in transient transfection assays. Using fusion polypeptides of ␤ enolase repressor factor 1 and the yeast GAL4 DNA-binding domain, we have identified an amino-terminal region responsible for the transcriptional repression activity, whereas a carboxyl-terminal region was shown to contain a potential transcriptional activation domain. The expression of this protein decreases in developing skeletal muscles, correlating with lack of binding activity in nuclear extract from adult skeletal tissue, in which novel binding activities have been detected. These results suggest that in addition to the identified factor, which functionally acts as a negative regulator and is enriched in embryonic muscle, the G-rich box binds other factors, presumably exerting a positive control on transcription. The interplay between factors that repress or activate transcription may constitute a developmentally regulated mechanism that modulates ␤ enolase gene expression in skeletal muscle.

Background miRNAs are master regulators of signaling pathways critically involved in asthma and are transferred between cells in extracellular vesicles (EV). We aimed to investigate whether the miRNA content of EV secreted by primary normal human bronchial epithelial cells (NHBE) is altered upon asthma development. Methods NHBE cells were cultured at air‐liquid interface and treated with interleukin (IL)‐13 to induce an asthma‐like phenotype. EV isolations by precipitation from basal culture medium or apical surface wash were characterized by nanoparticle tracking analysis, transmission electron microscopy, and Western blot, and EV‐associated miRNAs were identified by a RT‐qPCR‐based profiling. Significant candidates were confirmed in EVs isolated by size‐exclusion chromatography from nasal lavages of children with mild‐to‐moderate (n = 8) or severe asthma (n = 9), and healthy controls (n = 9). Results NHBE cells secrete EVs to the apical and basal side. 47 miRNAs were expressed in EVs and 16 thereof were significantly altered in basal EV upon IL‐13 treatment. Expression of miRNAs could be confirmed in EVs from human nasal lavages. Of note, levels of miR‐92b, miR‐210, and miR‐34a significantly correlated with lung function parameters in children (FEV1FVC%pred and FEF25‐75%pred), thus lower sEV‐miRNA levels in nasal lavages associated with airway obstruction. Subsequent ingenuity pathway analysis predicted the miRNAs to regulate Th2 polarization and dendritic cell maturation. Conclusion Our data indicate that secretion of miRNAs in EVs from the airway epithelium, in particular miR‐34a, miR‐92b, and miR‐210, might be involved in the early development of a Th2 response in the airways and asthma.