25 research outputs found

    Co-regulated expression of HAND2 and DEIN by a bidirectional promoter with asymmetrical activity in neuroblastoma

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    <p>Abstract</p> <p>Background</p> <p><it>HAND2</it>, a key regulator for the development of the sympathetic nervous system, is located on chromosome 4q33 in a head-to-head orientation with <it>DEIN</it>, a recently identified novel gene with stage specific expression in primary neuroblastoma (NB). Both genes are expressed in primary NB as well as most NB cell lines and are separated by a genomic sequence of 228 bp. The similar expression profile of both genes suggests a common transcriptional regulation mediated by a bidirectional promoter.</p> <p>Results</p> <p>Northern Blot analysis of <it>DEIN </it>and <it>HAND2 </it>in 20 primary NBs indicated concurrent expression levels of the two genes, which was confirmed by microarray analysis of 236 primary NBs (Pearson's correlation coefficient r = 0.65). While <it>DEIN </it>expression in the latter cohort was associated with stage 4S (p = 0.02), <it>HAND2 </it>expression was not associated with tumor stage. In contrast, both <it>HAND2 </it>and <it>DEIN </it>transcript levels were highly associated with age at diagnosis <12 months (p = 0.001). The intergenic region shows substantial homology in different species (89%, 72% and 53% identity between human and mouse, chicken and zebrafish, respectively) and contains many highly conserved putative transcription factor binding sites. Using luciferase reporter gene constructs, asymmetrical bidirectional promoter activity was found in four NB cell lines: In <it>DEIN </it>orientation, an average 3.4 fold increase in activity was observed as compared to the promoterless vector, whereas an average 15.4 fold activation was detected in <it>HAND2 </it>orientation. The presence of two highly conserved putative regulatory elements, one of which was shown to enhance <it>HAND2 </it>expression in branchial arches previously, displayed weak repressor activity for both genes.</p> <p>Conclusion</p> <p><it>HAND2 </it>and <it>DEIN </it>represent a gene pair that is tightly linked by a bidirectional promoter in an evolutionary highly conserved manner. Expression of both genes in NB is co-regulated by asymmetrical activity of this promoter and modulated by the activity of two cis-regulatory elements acting as weak repressors. The concurrent quantitative and tissue specific expression of <it>HAND2 </it>and <it>DEIN </it>suggests a functional link between both genes.</p

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Intravenous Streptokinase in Acute Myocardial Infarction (I.S.A.M.) trial: Serial evaluation of left ventricular function up to 3 years after infarction estimated by radionuclide ventriculography

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    AbstractThe Intravenous Streptokinase in Acute Myocardial Infarction (I.S.A.M.) trial was a prospective, placebo-controlled, doubleblind multicenter trial of high-dose short-term intravenous streptokinase in acute myocardial infarction administered within 6 h after the onset of symptoms. Global and regional left ventricular ejection fractions were determined by radionuclide ventriculography in a subset of 120 patients 3 days, 4 weeks, 7 months, 18 months and 3 years after acute myocardial infarction.In patients with anterior myocardial infarction, left ventricular ejection fraction was higher in the Streptokinase than in the placebo group 3 days after acute infarction (49 ± 14% vs. 40 ± 11%, p = 0.02). This difference of about 10% units in ejection fraction persisted during the 3 year follow-up period. Among streptokinase-treated patients, regional left ventricular ejection fraction was higher within the infarct zone as well as in remote myocardium throughout the follow-up period. Among patients with inferior infarction, no significant differences between the treatment and control groups were demonstrable with respect to global and regional left ventricular ejection fraction.Thus, intravenous administration of streptokinase within 6 h after the onset of symptorrs of acute myocardial infarction preserves left ventricular function over a period of ⩾3 years in patients with acute anterior myocardial infarction. It improves regional myocardial function within the infarct zone as well as in remote areas. In patients with acute inferior myocardial infarction, benefit from intravenous Streptokinase is of only minor degree

    Alterations of the Human Skin N- and O-Glycome in Basal Cell Carcinoma and Squamous Cell Carcinoma

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    The glycome of one of the largest and most exposed human organs, the skin, as well as glycan changes associated with non-melanoma skin cancers have not been studied in detail to date. Skin cancers such as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are among the most frequent types of cancers with rising incidence rates in the aging population. We investigated the healthy human skin N- and O-glycome and its changes associated with BCC and SCC. Matched patient samples were obtained from frozen biopsy and formalin-fixed paraffin-embedded tissue samples for glycomics analyses using two complementary glycomics approaches: porous graphitized carbon nano-liquid chromatography electro spray ionization tandem mass spectrometry and capillary gel electrophoresis with laser induced fluorescence detection. The human skin N-glycome is dominated by complex type N-glycans that exhibit almost similar levels of α2-3 and α2-6 sialylation. Fucose is attached exclusively to the N-glycan core. Core 1 and core 2 type O-glycans carried up to three sialic acid residues. An increase of oligomannose type N-glycans and core 2 type O-glycans was observed in BCC and SCC, while α2-3 sialylation levels were decreased in SCC but not in BCC. Furthermore, glycopeptide analyses provided insights into the glycoprotein candidates possibly associated with the observed N-glycan changes, with glycoproteins associated with binding events being the most frequently identified class.Full Tex

    Alterations of the Human Skin N- and O-Glycome in Basal Cell Carcinoma and Squamous Cell Carcinoma

    No full text
    The glycome of one of the largest and most exposed human organs, the skin, as well as glycan changes associated with non-melanoma skin cancers have not been studied in detail to date. Skin cancers such as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are among the most frequent types of cancers with rising incidence rates in the aging population. We investigated the healthy human skin N- and O-glycome and its changes associated with BCC and SCC. Matched patient samples were obtained from frozen biopsy and formalin-fixed paraffin-embedded tissue samples for glycomics analyses using two complementary glycomics approaches: porous graphitized carbon nano-liquid chromatography electro spray ionization tandem mass spectrometry and capillary gel electrophoresis with laser induced fluorescence detection. The human skin N-glycome is dominated by complex type N-glycans that exhibit almost similar levels of α2-3 and α2-6 sialylation. Fucose is attached exclusively to the N-glycan core. Core 1 and core 2 type O-glycans carried up to three sialic acid residues. An increase of oligomannose type N-glycans and core 2 type O-glycans was observed in BCC and SCC, while α2-3 sialylation levels were decreased in SCC but not in BCC. Furthermore, glycopeptide analyses provided insights into the glycoprotein candidates possibly associated with the observed N-glycan changes, with glycoproteins associated with binding events being the most frequently identified class

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    <p>The glycome of one of the largest and most exposed human organs, the skin, as well as glycan changes associated with non-melanoma skin cancers have not been studied in detail to date. Skin cancers such as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are among the most frequent types of cancers with rising incidence rates in the aging population. We investigated the healthy human skin N- and O-glycome and its changes associated with BCC and SCC. Matched patient samples were obtained from frozen biopsy and formalin-fixed paraffin-embedded tissue samples for glycomics analyses using two complementary glycomics approaches: porous graphitized carbon nano-liquid chromatography electro spray ionization tandem mass spectrometry and capillary gel electrophoresis with laser induced fluorescence detection. The human skin N-glycome is dominated by complex type N-glycans that exhibit almost similar levels of α2-3 and α2-6 sialylation. Fucose is attached exclusively to the N-glycan core. Core 1 and core 2 type O-glycans carried up to three sialic acid residues. An increase of oligomannose type N-glycans and core 2 type O-glycans was observed in BCC and SCC, while α2-3 sialylation levels were decreased in SCC but not in BCC. Furthermore, glycopeptide analyses provided insights into the glycoprotein candidates possibly associated with the observed N-glycan changes, with glycoproteins associated with binding events being the most frequently identified class.</p
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