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Background: Immunotherapies, including cancer vaccines and immune checkpoint inhibitors have transformed the management of many cancers. However, a large number of patients show resistance to these immunotherapies and current research has provided limited findings for predicting response to precision immunotherapy treatments. Methods: Here, we applied the next generation phage display mimotope variation analysis (MVA) to profile antibody response and dissect the role of humoral immunity in targeted cancer therapies, namely anti-tumor dendritic cell vaccine (MelCancerVac®) and immunotherapy with anti-PD-1 monoclonal antibodies (pembrolizumab). Results: Analysis of the antibody immune response led to the characterization of epitopes that were linked to melanoma-associated and cancer-testis antigens (CTA) whose antibody response was induced upon MelCancerVac® treatments of lung cancer. Several of these epitopes aligned to antigens with strong immune response in patients with unresectable metastatic melanoma receiving anti-PD-1 therapy. Conclusions: This study provides insights into the differences and similarities in tumor-specific immunogenicity related to targeted immune treatments. The antibody epitopes as biomarkers reflect melanoma-associated features of immune response, and also provide insights into the molecular pathways contributing to the pathogenesis of cancer. Concluding, antibody epitope response can be useful in predicting anti-cancer immunity elicited by immunotherapy.

The organ/tissue function replacement using implantable medical devices has become a pillar of modern medicine with a considerable level of success. Cochlear, orthopedic and dental implants are some of the examples of implantable medical devices with more than several million implantations per year. However, such an increased volume of use has also brought about an increased level of complications. One such complication is infections around medical devices, particularly in hospital settings where a significant portion of infections called ‘nosocomial infections’is closely related with implanted devices. Although there are certain indications such as smoking, presence of chronic systemic diseases and so on, there is no current method available to predict such medical complications.

Highlights • Using large-scale antibody profiling, differences between narcolepsy type 1 (NT1) and healthy controls became evident. • Prostaglandin D2 receptor DP1 was delineated as a novel autoantigenic target in NT1. • Utility of a 3-biomarker ELISPOT assay to assess exposure to H1N1 influenza virus and susceptibility to NT1 was demonstrated. This study reports on the diagnostic value of novel clinical biomarkers for detecting spontaneous and Pandemrix vaccine-associated NT1 and for stratification of A/H1N1 flu-specific response. Large-scale antibody profiling approach revealed the broad scope and high heterogeneity of NT1-associated immune response. We found a strong autoimmune-like response to prostaglandin D2 receptor DP1 suggesting a firm link between DP1/PDG2 and histamine pathways and the molecular basis of NT1. Together our results warrant further investigation of autoimmune ("self-") response in particular to PDG2 biosynthesis pathway as antibodies to the latter may modify the function of pharmaceutical compounds aimed at treating NT1., Background Neuropathological findings support an autoimmune etiology as an underlying factor for loss of orexin-producing neurons in spontaneous narcolepsy type 1 (narcolepsy with cataplexy; sNT1) as well as in Pandemrix influenza vaccine-induced narcolepsy type 1 (Pdmx-NT1). The precise molecular target or antigens for the immune response have, however, remained elusive. Methods Here we have performed a comprehensive antigenic repertoire analysis of sera using the next-generation phage display method - mimotope variation analysis (MVA). Samples from 64 children and adolescents were analyzed: 10 with Pdmx-NT1, 6 with sNT1, 16 Pandemrix-vaccinated, 16 H1N1 infected, and 16 unvaccinated healthy individuals. The diagnosis of NT1 was defined by the American Academy of Sleep Medicine international criteria of sleep disorders v3. Findings Our data showed that although the immunoprofiles toward vaccination were generally similar in study groups, there were also striking differences in immunoprofiles between sNT1 and Pdmx-NT1 groups as compared with controls. Prominent immune response was observed to a peptide epitope derived from prostaglandin D2 receptor (DP1), as well as peptides homologous to B cell lymphoma 6 protein. Further validation confirmed that these can act as true antigenic targets in discriminating NT1 diseased along with a novel epitope of hemagglutinin of H1N1 to delineate exposure to H1N1. Interpretation We propose that DP1 is a novel molecular target of autoimmune response and presents a potential diagnostic biomarker for NT1. DP1 is involved in the regulation of non-rapid eye movement (NREM) sleep and thus alterations in its functions could contribute to the disturbed sleep regulation in NT1 that warrants further studies. Together our results also show that MVA is a helpful method for finding novel peptide antigens to classify human autoimmune diseases, possibly facilitating the design of better therapies.

Background Inhibitor development is the most severe complication of hemophilia A care, and is associated with increased morbidity and mortality. Aims The aim of this study was to use a novel epitope mapping method to explore the factor VIII (FVIII)-specific epitope profile in the SIPPET cohort population. Methods The population consisted of 122 previously untreated patients with severe hemophilia A that were followed-up for 50 days of exposure to FVIII. Sampling was performed before FVIII treatment and at the end of the follow-up. The outcome was inhibitor development. The FVIII-specific IgG epitope repertoire was assessed by means of a novel high-throughput epitope mapping technique using a random peptide phage-display library. Using this assay, a set of affinity-selected 12-mer peptide sequences (also called mimotopes) that were strongly bound by FVIII-specific antibodies were identified. These mimotopes were clustered on the basis of sequence similarity and a consensus motif was generated for each mimotope cluster. Discriminative performance of these mimotope clusters was assessed by ROC analysis. Mimotope clusters were mapped onto the 3D structure of a B-domain deleted FVIII model using a B-cell epitope prediction algorithm (Mapitope). Results The FVIII-specific antibody response is polyclonal with several mimotope clusters. The most predominant mimotope clusters in inhibitor patients were mapped to the heavy chain of the FVIII molecule. Using plasma samples taken before exposure to FVIII, three mimotopes (with the consensus motifs "QM", "PSLxWK" and "SWPHxxxxK") were identified that predicted inhibitor development (with an AUC of 0.76, 0.80 and 0.76 respectively). Conclusion Information on immunodominant epitope clusters can be used to generate novel, less immunogenic FVIII proteins and set up diagnostic tests that predict the risk of inhibitor development before starting treatment with FVIII. Figure 1 Figure 1. Disclosures Palm: Protobios LLC: Current Employment, Patents & Royalties: Inventor of the patent application (PCT Application No. US/14079626) filed by Protobios that covers the use of phage display method to manipulate and monitor humoral immunity.. Palla: Pfizer: Other: Travel support; Kedrion: Other: Travel support; Novonordisk: Speakers Bureau. Peyvandi: Roche: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Sobi: Consultancy, Honoraria; Takeda: Consultancy, Honoraria.

Several research groups in Europe are active on different aspects of human picornavirus research. The AIROPico (Academia-Industry R&D Opportunities for Picornaviruses) consortium combined the disciplines of pathogenesis, diagnostics and therapy development in order to fill the gaps in our understanding of how picornaviruses cause human disease and how to combat them. AIROPico was the first EU consortium dedicated to human picornavirus research and development, and has largely accelerated and improved R&D on picornavirus biology, diagnostics and therapy. In this article, we present the progress on pathogenesis, diagnostics and treatment strategy developments for human picornaviruses resulting from the structured, translational research approach of the AIROPico consortium. We here summarize new insights in protection against infection by maternal or cross-protective antibodies, the visualisation of interactions between virus and neutralizing antibodies by cryoEM structural imaging, and the outcomes from a picornavirus-infected human 3D organoid. Progress in molecular detection and a fast typing assay for rhinovirus species are presented, as well as the identification of new compounds potentially interesting as therapeutic compounds. ispartof: ANTIVIRAL RESEARCH vol:161 pages:100-107 ispartof: location:Netherlands status: published

Trehangelins are trehalose angelates discovered from endophytic actinomycete Polymorphospora rubra K07-0510. We identified the trehangelin biosynthetic gene cluster, including genes that encode a glycoside hydrolase-like protein (thgC), α-amylase (thgD), 3-ketoacyl-ACP synthase III (thgI), 3-ketoacyl-ACP reductase (thgK), enoyl-CoA hydratase (thgH) and acyl transferase (thgJ). Heterologous expression of thgH, thgI, thgJ and thgK confirmed the importance of these genes in the biosynthesis of trehangelin A. Enzymatic activity studies showed that ThgI catalyses the condensation of acetyl-CoA and methylmalonyl-CoA to 2-methylacetoacetyl-CoA (MAA-CoA), ThgK catalyses NADPH-dependent reduction of MAA-CoA to 3-hydroxy-2-methylbutyryl-CoA (HMB-CoA) and ThgH catalyses the dehydration of HMB-CoA to angelyl-CoA (AN-CoA). This is the first report on the elucidation of the enzymatic formation of AN-CoA.

Changes in alternative splicing have been linked to cancer development. We hypothesized that changes occurring in tumor tissue can also be detected in the peripheral blood of cancer patients leading to discovery of blood biomarkers of breast cancer. Alternative splicing profiles of 94 genes were examined in cancerous breast tissue. Discriminating splice variants were analyzed in the peripheral blood of early stage (BCI/II) (stage I–II; n = 26), neoadjuvant receiving locally advanced breast cancer patients (LABC) (stage IIb–IIIa, b; n = 10) and healthy volunteers (n = 26) using qRT-PCR analysis. Changes in marker expression during neoadjuvant therapy were analyzed at 15 timepoints. High expression of REST-N50, the alternatively spliced variant of REST, was detected in the blood of LABC patients but not in BCI/II and healthy controls (p = 0.0032 and p = 0.0029, respectively). Expression levels of DOPEY1v2, the alternative splice variant of DOPEY1, in the blood could differentiate cancer from healthy controls (p = 0.024) and discriminate between patient groups (BCI/II vs LABC, p = 0.002). Positive response to neoadjuvant therapy of REST-N50-positive LABC patients correlated with a decrease in REST-N50 levels (p

Development is a highly controlled process of cell proliferation and differentiation driven by mechanisms of dynamic gene regulation. Specific DNA binding factors for establishing cell- and tissue-specific transcriptional programs have been characterised in different cell and animal models. However, much less is known about the role of “core transcription machinery” during cell differentiation, given that general transcription factors and their spatiotemporally patterned activity govern different aspects of cell function. In this review, we focus on the role of TATA-box associated factor 4 (TAF4) and its functional isoforms generated by alternative splicing in controlling lineage-specific differentiation of normal mesenchymal stem cells and cancer stem cells. In the light of our recent findings, induction, control and maintenance of cell differentiation status implies diversification of the transcription initiation apparatus orchestrated by alternative splicing.

Degenerate expression of transcription coregulator proteins is observed in most human cancers. Therefore, in targeted anti-cancer therapy development, intervention at the level of cancer-specific transcription is of high interest. The steroid receptor coactivator-1 (SRC-1) is highly expressed in breast, endometrial, and prostate cancer. It is present in various transcription complexes, including those containing nuclear hormone receptors. We examined the effects of a peptide that contains the LXXLL-motif of the human SRC-1 nuclear receptor box 1 linked to the cell-penetrating transportan 10 (TP10), hereafter referred to as TP10-SRC1LXXLL, on proliferation and estrogen-mediated transcription of breast cancer cells in vitro. Our data show that TP10-SRC1LXXLL induced dose-dependent cell death of breast cancer cells, and that this effect was not affected by estrogen receptor (ER) status. Surprisingly TP10-SRC1LXXLL severely reduced the viability and proliferation of hormone-unresponsive breast cancer MDA-MB-231 cells. In addition, the regulation of the endogenous ERα direct target gene pS2 was not affected by TP10-SRC1LXXLL in estrogen-stimulated MCF-7 cells. Dermal fibroblasts were similarly affected by treatment with higher concentrations of TP10-SRC1LXXLL and this effect was significantly delayed. These results suggest that the TP10-SRC1LXXLL peptide may be an effective drug candidate in the treatment of cancers with minimal therapeutic options, for example ER-negative tumors.

Reprogramming of somatic cells has become a versatile tool for biomedical research and for regenerative medicine. In the current study, we show that manipulating alternative splicing (AS) is a highly potent strategy to produce cells for therapeutic applications. We demonstrate that silencing of hTAF4-TAFH activity of TAF4 converts human facial dermal fibroblasts to melanocyte-like (iMel) cells. iMel cells produce melanin and express microphthalmia-associated transcription factor (MITF) and its target genes at levels comparable to normal melanocytes. Reprogramming of melanoma cells by manipulation with hTAF4-TAFH activity upon TAFH RNAi enforces cell differentiation towards chondrogenic pathway, whereas ectoptic expression of TAF4 results in enhanced multipotency and neural crest-like features in melanoma cells. In both cell states, iMels and cancer cells, hTAF4-TAFH activity controls migration by supporting E- to N-cadherin switches. From our data, we conclude that targeted splicing of hTAF4-TAFH coordinates AS of other TFIID subunits, underscoring the role of TAF4 in synchronised changes of Pol II complex composition essential for efficient cellular reprogramming. Taken together, targeted AS of TAF4 provides a unique strategy for generation of iMels and recapitulating stages of melanoma progression.

Brain-derived neurotrophic factor (BDNF), a member of the nerve growth factor family of neurotrophins, has central roles in the development, physiology, and pathology of the nervous system. We have elucidated the structure of the human BDNF gene, identified alternative transcripts, and studied their expression in adult human tissues and brain regions. In addition, the transcription initiation sites for human BDNF transcripts were determined and the activities of BDNF promoters were analyzed in transient overexpression assays. Our results show that the human BDNF gene has 11 exons and nine functional promoters that are used tissue and brain-region specifically. Furthermore, noncoding natural antisense RNAs that display complex splicing and expression patterns are transcribed in the BDNF gene locus from the antiBDNF gene (approved gene symbol BDNFOS). We show that BDNF and antiBDNF transcripts form dsRNA duplexes in the brain in vivo, suggesting an important role for antiBDNF in regulating BDNF expression in human.

Brain-derived neurotrophic factor (BDNF) has important functions in the development of the nervous system and in brain plasticity-related processes such as memory, learning, and drug addiction. Despite the fact that the function and regulation of rodent BDNF gene expression have received close attention during the last decade, knowledge of the structural organization of mouse and rat BDNF gene has remained incomplete. We have identified and characterized several mouse and rat BDNF transcripts containing novel 5′ untranslated exons and introduced a new numbering system for mouse and rat BDNF exons. According to our results both mouse and rat BDNF gene consist of eight 5′ untranslated exons and one protein coding 3′ exon. Transcription of the gene results in BDNF transcripts containing one of the eight 5′ exons spliced to the protein coding exon and in a transcript containing only 5′ extended protein coding exon. We also report the distinct tissue-specific expression profiles of each of the mouse and rat 5′ exon-specific transcripts in different brain regions and nonneural tissues. In addition, we show that kainic acid-induced seizures that lead to changes in cellular Ca2+ levels as well as inhibition of DNA methylation and histone deacetylation contribute to the differential regulation of the expression of BDNF transcripts. Finally, we confirm that mouse and rat BDNF gene loci do not encode antisense mRNA transcripts, suggesting that mechanisms of regulation for rodent and human BDNF genes differ substantially. © 2006 Wiley-Liss, Inc.

High activity of GLI family zinc finger protein 2 (GLI2) promotes tumor progression. Removal of the repressor domain at the N terminus (GLI2∆N) by recombinant methods converts GLI2 into a powerful transcriptional activator. However, molecular mechanisms leading to the formation of GLI2∆N activator proteins have not been established. Herein we report for the first time that the functional activities of GLI2 are parted into different protein isoforms by alternative promoter usage, selection of alternative splicing, transcription initiation and termination sites. Functional studies using melanoma cells revealed that transcriptional regulation of GLI2 is TGFbeta-dependent and supports the predominant production of GLI2∆N and C-terminally truncated GLI2 (GLI2∆C) isoforms in cells with high migratory and invasive phenotype. Taken together, these results highlight the role of transcription and RNA processing as major processes in the regulation of GLI2 activity with severe impacts in cancer development.

Expression of general transcription factor and co-activator TAF4 varies during development and in the processes of cell differentiation with suggested connection to neurodegenerative diseases. Here, we show that expression of TAF4 alternative splice variants is different in various regions of the human brain, substantiating the role of alternative splicing of TAF4 in the regulation of neural development and brain function. Most of the described splicing events affect the TAFH homology domain of TAF4 (hTAF4-TAFH). Besides, differentiated towards neural lineages, normal human neural progenitors (NHNPs) lose canonical full-length TAF4 isoform. To study the effects of hTAF4-TAFH splicing on neuronal differentiation, we used RNAi approach to target hTAF4-TAFH-encoding domain in NHNPs. Results show that inactivation of hTAF4-TAFH domain accelerates differentiation of human neural progenitor cells. Conversely, enhanced expression of TAF4 suppresses differentiation and keeps neural progenitor cells in a stem cell-like state. Finally, we provide data on the involvement of TP53 and noncanonical WNT signaling pathways in mediating effects of TAF4 on neuronal differentiation. Overall, our data suggest that specific isoforms of TAF4 may selectively and efficiently control neurogenesis.

Neuron-restrictive silencer element (NRSE) has been identified in multiple neuron-specific genes. This element has been shown to mediate repression of neuronal gene transcription in nonneuronal cells. A palindromic NRSE (NRSEBDNF) is present in the proximal region of brain-derived neurotrophic factor (BDNF) promoter II. Using in vitro binding assays, we establish that the upper half-site is largely responsible for the NRSEBDNF activity. To delineate the in vivorole of NRSE in the regulation of rat BDNF gene, promoter constructs with intact and mutated NRSEBDNF were introduced into transgenic mice. Our data show that NRSEBDNF is controlling the activity of BDNF promoters I and II in the brain, thymus, and lung,i.e. in the tissues in which the intact reporter gene and endogenous BDNF mRNAs are expressed. Mutation of NRSEBDNF did not lead to the ectopic activation of the reporter gene in any other nonneural tissues. In the brain, NRSEBDNF is involved in the repression of basal and kainic acid-induced expression from BDNF promoters I and II in neurons. However, NRSEBDNF does not control the activity of the BDNF gene in nonneuronal cells of brain.

The identification of a commoncis-acting silencer element, a neuron-restrictive silencer element (NRSE), in multiple neuron-specific genes, together with the finding that zinc finger transcription factor REST/NRSF/XBR could confer NRSE-mediated silencing in non-neuronal cells, suggested that REST/NRSF/XBR is a master negative regulator of neurogenesis. Here we show that, although REST/NRSF/XBR expression decreases during neuronal development, it proceeds in the adult nervous system.In situhybridization analysis revealed neuronal expression of rat REST/NRSF/XBR mRNA in adult brain, with the highest levels in the neurons of hippocampus, pons/medulla, and midbrain. The glutamate analog kainic acid increased REST/NRSF/XBR mRNA levels in various hippocampal and cortical neuronsin vivo, suggesting that REST/NRSF/XBR has a role in neuronal activity-implied processes. Several alternatively spliced REST/NRSF/XBR mRNAs encoding proteins with nine, five, or four zinc finger motifs are transcribed from REST/NRSF/XBR gene. Two of these transcripts are generated by neuron-specific splicing of a 28-bp-long exon. Rat REST/NRSF/XBR protein isoforms differ in their DNA binding specificities; however, all mediate repression in transient expression assays. Our data suggest that REST/NRSF/XBR is a negative regulator rather than a transcriptional silencer of neuronal gene expression and counteracts with positive regulators to modulate target gene expression quantitatively in different cell types, including neurons.

The purpose of the study was to identify and describe cervical cancer specific changes in humoral immune response by using a novel technology platform Mimotope Variation Analysis (MVA) developed by Protobios. The Janus Serum Bank is one of the world's oldest and largest population-based research biobanks established in 1973. The cohort is annually linked to the Cancer Registry of Norway using personal identification numbers. More than 1000 women have developed cervical cancer after donating sera. We identified sets of successive sera samples from ten patients with invasive cervical cancer, ten patients with pre-invasive cervical neoplasia and twenty cancer-free individuals (matched for age, gender, length of sample storage +3 months). For each subject we identified 4-10 samples donated to Janus over a period of up to 18 years, in total 213 samples. We applied MVA which combines phage display technology and high-throughput sequencing analysis to generate quantitative serologic profiles of millions of 12-mer peptide antigens called mimotopes from 2 μl of blood serum per analysis. Hierarchical clustering analysis of the top 5000 mimotopes from each sample resulted in individual-specific immunoprofiles. Multiple samples from the same person clustered together. Moreover, clustering reflected the time the sera was drawn suggesting that part of the individual immunoprofile is stabile over time. In conclusion, preliminary results suggests that Mimotope Variance Analysis generates individual-specific immunological profiles. This profile most likely reflect prior exposure environmental pathogens. Further, we aim to decode the differences in the immunological profiles between cancer patients and cancer-free subjects. Citation Format: Espen Enerly, Mari Nygård, Madleen Orumaa, Arno Pihlak, Susan Pihelgas, Hilde Langseth, Toomas Neuman, Kaia Palm. Mimotope variance analysis: A novel immunoprofiling method to monitor progression of cervical cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4039.

Brain-derived neurotrophic factor (BDNF) supports the survival of a specific set of neurons in the vertebrate nervous system. Here we show that the rat BDNF gene consists of four short 5' exons and one 3' exon encoding the mature BDNF protein. Eight different BDNF mRNAs with four different 5' ends and two alternative polyadenylation sites are transcribed from this gene. BDNF mRNAs containing exons I, II, and III are expressed predominantly in the brain, whereas exon IV transcripts predominate in the lung and heart. mRNAs containing exons I, II, and III increase markedly in the brain after kainic acid-induced seizures, whereas exon IV mRNA increases only slightly. Several transcription initiation sites were mapped upstream of the four 5' exons, and transfection of promoter-reporter gene constructs confirmed that these sequences act as promoters. Combined, the data demonstrate that alternative usage of four promoters within the BDNF gene and differential splicing control tissue-specific and seizure-induced expression of BDNF mRNA.

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family of neurotrophic factors, has important functions in the peripheral and central nervous system of vertebrates. We have generated bacterial artificial chromosome (BAC) transgenic mice harboring 207 kb of the rat BDNF (rBDNF) locus containing the gene, 13 kb of genomic sequences upstream of BDNF exon I, and 144 kb downstream of protein encoding exon IX, in which protein coding region was replaced with the lacZ reporter gene. This BDNF-BAC drove transgene expression in the brain, heart, and lung, recapitulating endogenous BDNF expression to a larger extent than shorter rat BDNF transgenes employed previously. Moreover, kainic acid induced the expression of the transgenic BDNF mRNA in the cerebral cortex and hippocampus through preferential activation of promoters I and IV, thus recapitulating neuronal activity-dependent transcription of the endogenous BDNF gene. genesis 48:214–219, 2010. © 2010 Wiley-Liss, Inc.

Delta–Notch signaling is a universal cell–cell communication pathway crucial for numerous developmental and physiological processes. Several proteins interact with and regulate the Notch pathway, including the E3 ubiquitin ligase Neuralized (Neur) that influences the stability and activity of Notch ligands. In mammals there are two homologs of Neur , Neur1 and Neur2, that both can interact with Notch ligands Delta-like1 and Jagged1. Here, we show that Neur2 , in contrast to Neur1 , is highly expressed during embryonic development of the brain and several non-neural tissues and its mRNA levels subside postnatally. In the hippocampal neurons of the adult brain Neur2 transcripts, in contrast to Neur1 , are excluded from the dendrites. Neur2 protein has a predominantly cytoplasmic localization. We also show that in addition to Delta-like1, Neur1 and Neur2 interact with another Notch ligand, Delta-like4.

J. Neurochem. (2009) 109, 807–818. Abstract The SWItch/Sucrose NonFermentable, a nucleosome remodeling complex (SWI/SNF) chromatin-remodelling complexes act upon the nucleosomal structure and regulate transcription, replication, repair of chromatin and splicing. In this study, we present evidence that human, mouse and rat genes encoding one of the SWI/SNF complex subunits, BAF57, undergo neuron-specific splicing of exons II, III and IV. Alternative splicing yields in at least three isoforms of BAF57 protein that have truncated N-termini (N-BAF57s). The transcripts encoding N-BAF57 isoforms are predominantly expressed in the nervous system. The biochemical fractionation data supported by the results of the co-immunoprecipitation analysis show that N-BAF57 isoforms associate into protein complexes together with Brg1, Brm, BAF155 and BAF170. Transient over-expression of N-BAF57 isoforms in non-neural cells affects the level of expression of certain neuron-restrictive silencer element-containing genes. Together these data suggest that neuronal isoforms of BAF57 contribute to functional SWI/SNF complexes regulating neurogenesis.

Background Brain-derived neurotrophic factor (BDNF) is a small secreted protein that has important roles in the developing and adult nervous system. Altered expression or changes in the regulation of the BDNF gene have been implicated in a variety of human nervous system disorders. Although regulation of the rodent BDNF gene has been extensively investigated, in vivo studies regarding the human BDNF gene are largely limited to postmortem analysis. Bacterial artificial chromosome (BAC) transgenic mice harboring the human BDNF gene and its regulatory flanking sequences constitute a useful tool for studying human BDNF gene regulation and for identification of therapeutic compounds modulating BDNF expression. Results In this study we have generated and analyzed BAC transgenic mice carrying 168 kb of the human BDNF locus modified such that BDNF coding sequence was replaced with the sequence of a fusion protein consisting of N-terminal BDNF and the enhanced green fluorescent protein (EGFP). The human BDNF-BAC construct containing all BDNF 5' exons preceded by different promoters recapitulated the expression of endogenous BDNF mRNA in the brain and several non-neural tissues of transgenic mice. All different 5' exon-specific BDNF-EGFP alternative transcripts were expressed from the transgenic human BDNF-BAC construct, resembling the expression of endogenous BDNF. Furthermore, BDNF-EGFP mRNA was induced upon treatment with kainic acid in a promotor-specific manner, similarly to that of the endogenous mouse BDNF mRNA. Conclusion Genomic region covering 67 kb of human BDNF gene, 84 kb of upstream and 17 kb of downstream sequences is sufficient to drive tissue-specific and kainic acid-induced expression of the reporter gene in transgenic mice. The pattern of expression of the transgene is highly similar to BDNF gene expression in mouse and human. This is the first study to show that human BDNF gene is regulated by neural activity.

Drosophila neurogenic gene neuralized (neu) is required for the maintenance of neuroblast cell fate and differentiation. In the present study we have characterized a mouse and a rat homologue of Drosophila neu. Mammalian neu1 encodes several C-terminal RING zinc finger proteins with one or two neuralized homology repeat (NHR) domains. Mammalian neu1 mRNAs are predominantly expressed in the nervous system and in the skeletal muscle with the highest levels in the adult. In the nervous system neu1 mRNAs are expressed in neurons and dendritically localized in several brain regions, suggesting a role of neu1 in the regulation of synaptic function. Mammalian neu1 isoforms exhibit transcription repression activities that are mediated by NHR domains and regulated by nucleocytoplasmic shuttling. In conclusion, our results suggest that mammalian neu1 is a protein with transcriptional repressor activities involved in the regulation of myo- and neurogenesis.

Liver transplantation is the only clinically effective method of treating acute liver failure. However, wider application of this therapeutic modality is restricted primarily by shortage of donor organs. In the search for alternative methods of liver replacement therapy, investigators have focused on transplantation of normal allogeneic hepatocytes and on the development of liver support systems utilizing isolated hepatocytes. Since all human livers suitable for cell harvest are being used for transplantation, hepatocyte therapy using human tissue would require growing of cells in vitro. Unfortunately, although hepatocytes have tremendous capacity to proliferate in vivo, their ability to grow in culture is severely limited. Stromal cells from bone marrow and other blood-forming organs have been found to support hematopoiesis. In this paper, we show that bone marrow-derived stromal cells (BMSCs) enhance proliferation and support differentiation of rat hepatocytes in culture. Further, we demonstrate that in hepatocyte/BMSC co-cultures, clonal expansion of small hepatocytes (SH) is increased. Using semipermeable membrane cultures, we established that direct cell–cell contact is necessary for stimulation of cell proliferation. We also show that BMSCs which are in direct contact with hepatocytes and SH colonies express Jagged1. This suggests a potential role for Notch signaling in the observed effects. Finally, we present evidence that the expression and activity of liver specific transcirption factors, CCAAT/enhancer binding proteins and liver specific key enzymes such as tryptophan 2,3-dioxygenase, are improved in hepatocyte/BMSC co-cultures. In conclusion, results of this study indicate that BMSCs could facilitate proliferation and differentiation of primary rat hepatocytes and their progenitors (SH) in vitro. © 2001 Wiley-Liss, Inc.

The mammalian central nervous system (CNS) contains multipotent stem cells that develop into neurons, astrocytes and oligodendrocytes. Our current data show that fetal and adult human CNS stem cell isolates display similar proliferation kinetics, differentiate into three major cell types of the nervous system and express similar sets of regulatory genes. However, each individual CNS stem cell isolate could be distinguished by its specific gene expression and developmental potential.

Neuron-restrictive silencer factor (NRSF), also known as repressor element RE1 binding transcription factor (REST) or repressor binding to the X2 box (XBR) (REST/NRSF/XBR), is a zinc finger transcription factor that during early embryogenesis is required to repress a subset of neuron-specific genes in non-neural tissues and undifferentiated neural precursors. We have previously shown that splicing within the coding region of rat REST/NRSF/XBR (rREST) generates several different transcripts all of which are expressed in the adult nervous system. rREST transcripts with short neuron-specific exons (exon N) have in-frame stop codons and encode truncated proteins which have an N-terminal repressor domain and weakened DNA binding activity. The aim of this study was to analyze the regulatory mechanisms underlying REST/NRSF/XBR activity in human and mouse as compared to rat. We show that the structure of REST/NRSF/XBR gene and its regulation by neuron-specific splicing is conserved in human, mouse and rat. Expression levels of REST/NRSF/XBR transcripts with the insertion of exon N are increased during the neuronal differentiation of mouse teratocarcinoma PCC7 and rat pheocromocytoma PC12 cells and are high in several human and mouse neuroblastoma cells as compared to the relatively low levels in the developing and adult nervous system. The exclusive expression of the neuronal forms of REST/NRSF/XBR mRNAs in mouse neuroblastoma Neuro-2A cells is not caused by rearrangement of the REST/NRSF/XBR gene nor by mutations in the sequence of the splice sites flanking exon N. These data suggest that changes in REST/NRSF/XBR splicing pattern may result from altered levels of splicing factors reflecting the formation and/or progression of neuroblastoma tumors.

Little is known about the quality of polyclonal antibody responses in COVID-19 patients, and how it correlates with disease severity or patients' prior exposure to other pathogens. The whole polyclonal antibody repertoire in a retrospective cohort of 538 individuals was mapped against SARS-CoV-2 spike (S) glycoprotein, the main target of antibody immune responses in SARS-CoV-2 infection. Bioinformatic predictions identified 15 major B cell epitopes for S of SARS-CoV-2. Several epitopes localised in RBD of S including those spanning the ACE2-binding site, the highly conserved cryptic epitope of the neutralizing antibody of SARS-CoV, and fusion/entry domains of HR1 and HR2 of S protein of SARS-CoV-2. Intriguingly, some of these epitopes have cross-reactivity to antigens of common pathogens, potentially affecting SARS-CoV-2 infection outcome. High level of anti-Spike SARS-CoV-2 seroreactivity in populations with no history of exposure to SARS-CoV-2 is of clinical relevance and could underpin better understanding of COVID-19 pathophysiology in different populations and provide a blueprint for design of effective vaccines and developing better strategies for antibody testing.