CK2 Phosphorylation of Schistosoma mansoni HMGB1 Protein Regulates Its Cellular Traffic and Secretion but Not Its DNA Transactions

parasite resides in mesenteric veins where fecundated female worms lay hundred of eggs daily. Some of the egg antigens are trapped in the liver and induce a vigorous granulomatous response. High Mobility Group Box 1 (HMGB1), a nuclear factor, can also be secreted and act as a cytokine. Schistosome HMGB1 (SmHMGB1) is secreted by the eggs and stimulate the production of key cytokines involved in the pathology of schistosomiasis. Thus, understanding the mechanism of SmHMGB1 release becomes mandatory. Here, we addressed the question of how the nuclear SmHMGB1 can reach the extracellular space. eggs of infected animals and that SmHMGB1 that were localized in the periovular schistosomotic granuloma were phosphorylated.We showed that secretion of SmHMGB1 is regulated by phosphorylation. Moreover, our results suggest that egg-secreted SmHMGB1 may represent a new egg antigen. Therefore, the identification of drugs that specifically target phosphorylation of SmHMGB1 might block its secretion and interfere with the pathogenesis of schistosomiasis

Differential Epigenetic Regulation of TOX Subfamily High Mobility Group Box Genes in Lung and Breast Cancers

Aberrant cytosine methylation affects regulation of hundreds of genes during cancer development. In this study, a novel aberrantly hypermethylated CpG island in cancer was discovered within the TOX2 promoter. TOX2 was unmethylated in normal cells but 28% lung (n = 190) and 23% breast (n = 80) tumors were methylated. Expression of two novel TOX2 transcripts identified was significantly reduced in primary lung tumors than distant normal lung (p<0.05). These transcripts were silenced in methylated lung and breast cancer cells and 5-Aza-2-deoxycytidine treatment re-expressed both. Extension of these assays to TOX, TOX3, and TOX4 genes that share similar genomic structure and protein homology with TOX2 revealed distinct methylation profiles by smoking status, histology, and cancer type. TOX was almost exclusively methylated in breast (43%) than lung (5%) cancer, whereas TOX3 was frequently methylated in lung (58%) than breast (30%) tumors. TOX4 was unmethylated in all samples and showed the highest expression in normal lung. Compared to TOX4, expression of TOX, TOX2 and TOX3 in normal lung was 25, 44, and 88% lower, respectively, supporting the premise that reduced promoter activity confers increased susceptibility to methylation during lung carcinogenesis. Genome-wide assays revealed that siRNA-mediated TOX2 knockdown modulated multiple pathways while TOX3 inactivation targeted neuronal development and function. Although these knockdowns did not result in further phenotypic changes of lung cancer cells in vitro, the impact on tissue remodeling, inflammatory response, and cell differentiation pathways suggest a potential role for TOX2 in modulating tumor microenvironment

A High-Sensitivity Method for Detection and Measurement of HMGB1 Protein Concentration by High-Affinity Binding to DNA Hemicatenanes

BACKGROUND: Protein HMGB1, an abundant nuclear non-histone protein that interacts with DNA and has an architectural function in chromatin, was strikingly shown some years ago to also possess an extracellular function as an alarmin and a mediator of inflammation. This extracellular function has since been actively studied, both from a fundamental point of view and in relation to the involvement of HMGB1 in inflammatory diseases. A prerequisite for such studies is the ability to detect HMGB1 in blood or other biological fluids and to accurately measure its concentration. METHODOLOGY/PRINCIPAL FINDINGS: In addition to classical techniques (western blot, ELISA) that make use of specific anti-HMGB1 antibodies, we present here a new, extremely sensitive technique that is based on the fact that hemicatenated DNA loops (hcDNA) bind HMGB1 with extremely high affinity, higher than the affinity of specific antibodies, similar in that respect to DNA aptamers. DNA-protein complexes formed between HMGB1 and radiolabeled hcDNA are analyzed by electrophoresis on nondenaturing polyacrylamide gels using the band-shift assay method. In addition, using a simple and fast protocol to purify HMGB1 on the basis of its solubility in perchloric acid allowed us to increase the sensitivity by suppressing any nonspecific background. The technique can reliably detect HMGB1 at a concentration of 1 pg per microliter in complex fluids such as serum, and at much lower concentrations in less complex samples. It compares favorably with ELISA in terms of sensitivity and background, and is less prone to interference from masking proteins in serum. CONCLUSION: The new technique, which illustrates the potential of DNA nanoobjects and aptamers to form high-affinity complexes with selected proteins, should provide a valuable tool to further investigate the extracellular functions of HMGB1 and its involvement in inflammatory pathologies

Disease awareness campaigns in printed and online media in Latvia : Cross-sectional study on consistency with WHO ethical criteria for medicinal drug promotion and European standards

Funding Information: Teresa Leonardo Alves declares no conflicts of interest. She has worked in the past for not-for-profit organizations which have advocated against the relaxation of the direct-to-consumer advertising ban in the European Union, namely Prescrire (2012–2016) and Health Action International (2006–2011). Elita Poplavska is a board member of not-for-profit organizations - Health Projects for Latvia and Health Action International (which aim to promote rational use of medicines and reduce influence of pharmaceutical advertisement). Signe Mezinska is a board member of not-for-profit organizations - Health Projects for Latvia and Health Action International (which aim to promote rational use of medicines and reduce influence of pharmaceutical advertisement). Ieva Salmane-Kulikovska declares no conflicts of interest. Liga Andersone declares no conflicts of interest. Aukje Mantel-Teeuwisse is the Managing Director of the WHO Collaborating Centre for Pharmaceutical Policy & Regulation, which receives no direct funding or donations from private parties, including the pharmaceutical industry. Research funding from public-private partnerships, e.g. IMI, Lygature (https://www.lygature.org), is accepted under the condition that no company-specific product or company-related study is conducted. The Centre has received unrestricted research funding from public sources, e.g. Netherlands Organisation for Health Research and Development (ZonMW), Zorg Instituut Nederland (ZIN), the Dutch Medicines Evaluation Board (MEB), and the Dutch Ministry of Health. Barbara Mintzes has acted as an expert witness on behalf of plaintiffs in a Canadian class action suit on cardiovascular risks of testosterone therapy. Publisher Copyright: © 2018 The Author(s).Background: European legislation prohibits direct-to-consumer advertising of prescription medicines, but allows drug manufacturers to provide information to the public on health and diseases. Our aim was to measure the frequency of disease awareness campaigns in Latvian media and assess their compliance with international and European standards. Methods: Materials on health/disease and treatments were collected between April and September 2015 from 12 newspapers and magazines and six online portals. Disease awareness campaigns were assessed using a previously developed instrument based on the WHO Ethical Criteria for Medicinal Drug promotion and European standards (EU law and pharmaceutical industry self-regulatory guidelines). Collected materials were used to examine the information provided on medical conditions and their diagnosis and treatment. The inter-rater reliability was calculated. Results: We collected 263 materials from print (n = 149) and online media (n = 114); 94 were news items and 169 were disease-awareness advertisements. Cancer, cardiovascular problems, allergies and respiratory diseases were common topics. Of the 157 campaigns assessed, non-compliance was identified in 149 cases (inter-rater reliability 90%), mainly due to misleading or incomplete information, lack of balance and the absence of a listed author/sponsor. Six disease awareness campaigns directly mentioned a pharmaceutical product by brand name and other four included the logo or name of a manufacturer, referred to a condition and indirectly mentioned a treatment, all in contravention with European law. Conclusions: The compliance of disease awareness campaigns in Latvian media with international and European standards is low. This raises concerns about the nature of information being conveyed. Through lack of balance, missing sponsorship information, and misleading or incomplete information, these campaigns could contribute to inaccurate self-diagnosis and generate demand among those who might not need medical treatment.publishersversionPeer reviewe

Identification and Characterization of the Lamprey High-Mobility Group Box 1 Gene

High-mobility group box 1 (HMGB1), a highly conserved DNA-binding protein, plays an important role in maintaining nucleosome structures, transcription, and inflammation. We identified a homolog of HMGB1 in the Japanese lamprey (Lampetra japonica). The Lampetra japonica HMGB1 gene (Lj-HMGB1) has over 70% sequence identity with its homologs in jawed vertebrates. Despite the reasonably high sequence identity with other HMGB1 proteins, Lj-HMGB1 did not group together with these proteins in a phylogenetic analysis. We examined Lj-HMGB1 expression in lymphocyte-like cells, and the kidneys, heart, gills, and intestines of lampreys before and after the animals were challenged with lipopolysaccharide (LPS) and concanavalin A (ConA). Lj-HMGB1 was initially expressed at a higher level in the heart, but after treatment with LPS and ConA only the gills demonstrated a significant up-regulation of expression. The recombinant Lj-HMGB1 (rLj-HMGB1) protein bound double-stranded DNA and induced the proliferation of human adenocarcinoma cells to a similar extent as human HMGB1. We further revealed that Lj-HMGB1 was able to induce the production of tumor necrosis factor-α (TNF-α), a pro-inflammatory mediator, in activated human acute monocytic leukemia cells. These results suggest that lampreys use HMGB1 to activate their innate immunity for the purpose of pathogen defense

Nuclear protein LEDGF/p75 recognizes supercoiled DNA by a novel DNA-binding domain

Lens epithelium-derived growth factor (LEDGF) or p75 is a co-activator of general transcription and also involved in insertion of human immunodeficiency virus type I (HIV-1) cDNA into host cell genome, which occurs preferentially to active transcription units. These phenomena may share an underlying molecular mechanism in common. We report here that LEDGF/p75 binds negatively supercoiled DNA selectively over unconstrained DNA. We identified a novel DNA-binding domain in the protein and termed it ‘supercoiled DNA-recognition domain’ (SRD). Recombinant protein fragments containing SRD showed a preferential binding to supercoiled DNA in vitro. SRD harbors a characteristic cluster of lysine and glutamic/aspartic acid residues. A polypeptide mimicking the cluster (K9E9K9) also showed this specificity, suggesting that the cluster is an essential element for the supercoil recognition. eGFP-tagged LEDGF/p75 expressed in the nucleus distributed partially in transcriptionally active regions that were identified by immunostaining of methylated histone H3 (H3K4me3) or incorporation of Br-UTP. This pattern of localization was observed with SRD alone but abolished if the protein lacked SRD. Thus, these results imply that LEDGF/p75 guides its binding partners, including HIV-1 integrase, to the active transcription site through recognition of negative supercoils generated around it

Escape of HIV-1-Infected Dendritic Cells from TRAIL-Mediated NK Cell Cytotoxicity during NK-DC Cross-Talk—A Pivotal Role of HMGB1

Early stages of Human Immunodeficiency Virus-1 (HIV-1) infection are associated with local recruitment and activation of important effectors of innate immunity, i.e. natural killer (NK) cells and dendritic cells (DCs). Immature DCs (iDCs) capture HIV-1 through specific receptors and can disseminate the infection to lymphoid tissues following their migration, which is associated to a maturation process. This process is dependent on NK cells, whose role is to keep in check the quality and the quantity of DCs undergoing maturation. If DC maturation is inappropriate, NK cells will kill them (“editing process”) at sites of tissue inflammation, thus optimizing the adaptive immunity. In the context of a viral infection, NK-dependent killing of infected-DCs is a crucial event required for early elimination of infected target cells. Here, we report that NK-mediated editing of iDCs is impaired if DCs are infected with HIV-1. We first addressed the question of the mechanisms involved in iDC editing, and we show that cognate NK-iDC interaction triggers apoptosis via the TNF-related apoptosis-inducing ligand (TRAIL)-Death Receptor 4 (DR4) pathway and not via the perforin pathway. Nevertheless, once infected with HIV-1, DCHIV become resistant to NK-induced TRAIL-mediated apoptosis. This resistance occurs despite normal amounts of TRAIL released by NK cells and comparable DR4 expression on DCHIV. The escape of DCHIV from NK killing is due to the upregulation of two anti-apoptotic molecules, the cellular-Flice like inhibitory protein (c-FLIP) and the cellular inhibitor of apoptosis 2 (c-IAP2), induced by NK-DCHIV cognate interaction. High-mobility group box 1 (HMGB1), an alarmin and a key mediator of NK-DC cross-talk, was found to play a pivotal role in NK-dependent upregulation of c-FLIP and c-IAP2 in DCHIV. Finally, we demonstrate that restoration of DCHIV susceptibility to NK-induced TRAIL killing can be obtained either by silencing c-FLIP and c-IAP2 by specific siRNA, or by inhibiting HMGB1 with blocking antibodies or glycyrrhizin, arguing for a key role of HMGB1 in TRAIL resistance and DCHIV survival. These findings provide evidence for a new strategy developed by HIV to escape immune attack, they challenge the question of the involvement of HMGB1 in the establishment of viral reservoirs in DCs, and they identify potential therapeutic targets to eliminate infected DCs

Transcriptional and Post-Transcriptional Regulation of SPAST, the Gene Most Frequently Mutated in Hereditary Spastic Paraplegia

Hereditary spastic paraplegias (HSPs) comprise a group of neurodegenerative disorders that are characterized by progressive spasticity of the lower extremities, due to axonal degeneration in the corticospinal motor tracts. HSPs are genetically heterogeneous and show autosomal dominant inheritance in ∼70–80% of cases, with additional cases being recessive or X-linked. The most common type of HSP is SPG4 with mutations in the SPAST gene, encoding spastin, which occurs in 40% of dominantly inherited cases and in ∼10% of sporadic cases. Both loss-of-function and dominant-negative mutation mechanisms have been described for SPG4, suggesting that precise or stoichiometric levels of spastin are necessary for biological function. Therefore, we hypothesized that regulatory mechanisms controlling expression of SPAST are important determinants of spastin biology, and if altered, could contribute to the development and progression of the disease. To examine the transcriptional and post-transcriptional regulation of SPAST, we used molecular phylogenetic methods to identify conserved sequences for putative transcription factor binding sites and miRNA targeting motifs in the SPAST promoter and 3′-UTR, respectively. By a variety of molecular methods, we demonstrate that SPAST transcription is positively regulated by NRF1 and SOX11. Furthermore, we show that miR-96 and miR-182 negatively regulate SPAST by effects on mRNA stability and protein level. These transcriptional and miRNA regulatory mechanisms provide new functional targets for mutation screening and therapeutic targeting in HSP

Senescent cells as a source of inflammatory factors for tumor progression

Cellular senescence, which is associated with aging, is a process by which cells enter a state of permanent cell cycle arrest, therefore constituting a potent tumor suppressive mechanism. Recent studies show that, despite the beneficial effects of cellular senescence, senescent cells can also exert harmful effects on the tissue microenvironment. The most significant of these effects is the acquisition of a senescent-associated secretory phenotype (SASP), which entails a striking increase in the secretion of pro-inflammatory cytokines. Here, we summarize our knowledge of the SASP and the impact it has on tissue microenvironments and ability to stimulate tumor progression

In vitro nuclear interactome of the HIV-1 Tat protein

<p>Abstract</p> <p>Background</p> <p>One facet of the complexity underlying the biology of HIV-1 resides not only in its limited number of viral proteins, but in the extensive repertoire of cellular proteins they interact with and their higher-order assembly. HIV-1 encodes the regulatory protein Tat (86–101aa), which is essential for HIV-1 replication and primarily orchestrates HIV-1 provirus transcriptional regulation. Previous studies have demonstrated that Tat function is highly dependent on specific interactions with a range of cellular proteins. However they can only partially account for the intricate molecular mechanisms underlying the dynamics of proviral gene expression. To obtain a comprehensive nuclear interaction map of Tat in T-cells, we have designed a proteomic strategy based on affinity chromatography coupled with mass spectrometry.</p> <p>Results</p> <p>Our approach resulted in the identification of a total of 183 candidates as Tat nuclear partners, 90% of which have not been previously characterised. Subsequently we applied <it>in silico </it>analysis, to validate and characterise our dataset which revealed that the Tat nuclear interactome exhibits unique signature(s). First, motif composition analysis highlighted that our dataset is enriched for domains mediating protein, RNA and DNA interactions, and helicase and ATPase activities. Secondly, functional classification and network reconstruction clearly depicted Tat as a polyvalent protein adaptor and positioned Tat at the nexus of a densely interconnected interaction network involved in a range of biological processes which included gene expression regulation, RNA biogenesis, chromatin structure, chromosome organisation, DNA replication and nuclear architecture.</p> <p>Conclusion</p> <p>We have completed the <it>in vitro </it>Tat nuclear interactome and have highlighted its modular network properties and particularly those involved in the coordination of gene expression by Tat. Ultimately, the highly specialised set of molecular interactions identified will provide a framework to further advance our understanding of the mechanisms of HIV-1 proviral gene silencing and activation.</p