Streptomyces sporulation - Genes and regulators involved in bacterial cell differentiation

Streptomycetes are Gram-positive bacteria with a complex developmental life cycle. They form spores on specialized cells called aerial hyphae, and this sporulation involves alterations in growth, morphogenesis and cell cycle processes like cell division and chromosome segregation. Understanding the developmental mechanisms that streptomycetes have evolved for regulating for example cell division is of general interest in bacterial cell biology. It can also be valuable in the design of new drugs against bacterial pathogens. Very few sporulation genes have been found with an impact on cell cycle-related processes. Finding of such genes is important for a clarification of the molecular mechanisms that are underlying the developmental control of fundamental cellular processes in Streptomyces. The work of this thesis has led to the identification of genes previously unknown to be developmentally regulated in Streptomyces. By comparing the transcriptome of the wildtype S. coelicolor strain M145 to two developmental mutants, whiA and whiH, which specifically affect sporulation processes, it was possible to identify differentially expressed genes. Genes that so far have been characterized proved to have important roles during sporulation, affecting spore maturation, chromosome condensation and cell division. WhiH is a central regulator in the early sporulation process and required for the developmentally controlled form of cell division in S. coelicolor. In this thesis the role of WhiH as a transcription factor has been established and WhiH was found to bind to a specific site in its own promoter and function as an autoregulator. A whiHp-mCherry reporter fusion was used to monitor cell type-specific activity of the whiH promoter in aerial hyphae, and showed that it is active before delimitation of the sporogenic cell in which multiple developmentally controlled cell divisions will be triggered. A new Streptomyces model organism, S. venezuelae, was finally exploited to identify target genes for control by WhiH. This organism sporulates efficiently in liquid culture and is well suited for global transcriptomic approaches. In this study, microarray analysis of whiH-dependent gene expression was used to find putative targets for WhiH. Combined with chromatin-immunoprecipitation (ChIP-chip) and protein-DNA binding assays this identified a group of genes that are directly repressed by WhiH during a late stage of sporulation, and also some candidate genes that could be activated by WhiH at an earlier stage. Future analyses should shed light on the functions of these genes and their potential roles in developmental and cell cycle-related processes

Cries and whispers: exhuming and narrating defeat in Spain today

In this paper, I will reflect on the impact in contemporary Spain of the production, circulation and consumption of narratives and images of Civil War terror and suffering, specifically those resulting from the opening of mass graves from the Francoist repression. This sharing of narratives has to be seen in the context of a broader and highly controversial process of reconsideration of the Civil War as a traumatic past. At a time when Spanish society is engaged in important debates regarding the singularity or plurality of our identity and the structure of our territorial organization, these exhumations are bringing to light rather disturbing information regarding our past, our present, and probably our future as well. The excavation of these “crime scenes” in various parts of the country is provoking heated discussions and performances in family contexts, politics, historiography, the media, the arts, and the public sphere in general. For example, the public display of skeletons, skulls and bone fragments bearing the marks of violence – from “perimortem” tortures to bullet wounds and coups de grâce – is bringing back tragic stories that, for many relatives but also for civil society at large, were for decades mostly silenced, told in whispers, imperfectly transmitted in limited family circles, or simply ignored. The screen of silence, fear and self-censorship has been particularly strong in local, rural contexts. Exhumation and narration are inextricably entwined. Exhumations elicit storytelling; conversely, their meaning and social impact depend on the available repertoire of competing “memory plots".Peer reviewe

Överföring av företagsidentitet till en franchiseenhet -En studie av IKEA

Uppsatsen inom Service Management vid Lunds Universitet, campus Helsingborg, behandlar den problematik som kan uppstå kring spridandet av ett företags identitet till dess franchiseenheter. Syftet med uppsatsen är att se hur en utomstående ägare till en enhet kan påverka hur företagets identitet sprids och bibehålls. Vår primära metod har varit intervjuer med personer som har nära anknytning till IKEA:s franchiseenheter. Den sekundära metod vi har använt oss av är dokumentstudier. Franchising är ett bra sätt för företag som IKEA att kunna nå ut på marknader som annars vore svåra att etablera sig på. Men med det externa ägarskapet som franchising medför, kommer också svårigheter som grundar sig i agentrelationen. Då franchisetagaren har investerat en stor del eget kapital i verksamheten, tycks dennes lönsamhets- och kostnadsfokusering vara extremt kraftig. Detta medför att kostnader som är tänkta till att bevara en viktig del av företagsidentiteten, nämligen företagskulturen, bortprioriteras hos franchisetagaren för att denne har svårt att se nyttan med investeringen. Fokus försvinner därmed från företagets annars så viktiga företagskultur, och riktas istället på prestation och försäljning. Vi har funnit att ledarskapet, som också utgör en viktig del i företagsidentiteten, kan skilja sig åt i en franchiseenhet från det som är förenligt med företagets värderingar. Även symboler är en viktig beståndsdel i företagsidentiteten. De symboler som är materiella i form av exempelvis bilder, och verbala i form av till exempel slogans, är de faktorer som är mest standardiserade i företagsidentiteten. Symbolernas standardisering i kombination med att de är billiga att överföra till franchiseenheter gör att dessa faktorer är den del av företagets identitet som är lättast att sprida till franchiseenheter, och som även lyckas bäst

Cerebrospinal fluid proteomic study of two bipolar disorder cohorts

The pathophysiology of bipolar disorder remains to be elucidated and there are no diagnostic or prognostic biomarkers for the condition. In this explorative proteomic study, we analyzed 201 proteins in cerebrospinal fluid (CSF) from mood stable bipolar disorder patients and control subjects sampled from two independent cohorts, amounting to a total of 204 patients and 144 controls. We used three Olink Multiplex panels, whereof one specifically targets immune biomarkers, to assess a broad set of CSF protein concentrations. After quality control and removal of proteins with a low detection rate, 105 proteins remained for analyses in relation to case-control status and clinical variables. Only case-control differences that replicated across cohorts were considered. Results adjusted for potential confounders showed that CSF concentrations of growth hormone were lower in bipolar disorder compared with controls in both cohorts. The effect size was larger when the analysis was restricted to bipolar disorder type 1 and controls. We found no indications of immune activation or other aberrations. Growth hormone exerts many effects in the central nervous system and our findings suggest that growth hormone might be implicated in the pathophysiology of bipolar disorder

Characterization of the Aquaporin-9 Inhibitor RG100204 In Vitro and in db/db Mice

Aquaporin-9 (AQP9) is a facilitator of glycerol and other small neutral solute transmembrane diffusion. Identification of specific inhibitors for aquaporin family proteins has been difficult, due to high sequence similarity between the 13 human isoforms, and due to the limited channel surface areas that permit inhibitor binding. The few AQP9 inhibitor molecules described to date were not suitable for in vivo experiments. We now describe the characterization of a new small molecule AQP9 inhibitor, RG100204 in cell-based calcein-quenching assays, and by stopped-flow light-scattering recordings of AQP9 permeability in proteoliposomes. Moreover, we investigated the effects of RG100204 on glycerol metabolism in mice. In cell-based assays, RG100204 blocked AQP9 water permeability and glycerol permeability with similar, high potency (~5 × 10-8 M). AQP9 channel blocking by RG100204 was confirmed in proteoliposomes. After oral gavage of db/db mice with RG100204, a dose-dependent elevation of plasma glycerol was observed. A blood glucose-lowering effect was not statistically significant. These experiments establish RG100204 as a direct blocker of the AQP9 channel, and suggest its use as an experimental tool for in vivo experiments on AQP9 function

Risk for self-reported anorexia or bulimia nervosa based on drive for thinness and negative affect clusters/dimensions during adolescence: A three-year prospective study of the TChAD cohort: Drive for Thinness and Negative Affect

The present study explored the cross-sectional and predictive effect of drive for thinness and/or negative affect scores on the development of self-reported anorexia nervosa (AN) and bulimia nervosa (BN)

DNA methylation holds prognostic information in relapsed precursor B-cell acute lymphoblastic leukemia

Background: Few biological markers are associated with survival after relapse of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). In pediatric T-cell ALL, we have identified promoter-associated methylation alterations that correlate with prognosis. Here, the prognostic relevance of CpG island methylation phenotype (CIMP) classification was investigated in pediatric BCP-ALL patients. Methods: Six hundred and one BCP-ALL samples from Nordic pediatric patients (age 1-18) were CIMP classified at initial diagnosis and analyzed in relation to clinical data. Results: Among the 137 patients that later relapsed, patients with a CIMP-profile (n = 42) at initial diagnosis had an inferior overall survival (pOS(5years) 33%) compared to CIMP+ patients (n = 95, pOS(5years) 65%) (p = 0.001), which remained significant in a Cox proportional hazards model including previously defined risk factors. Conclusion: CIMP classification is a strong candidate for improved risk stratification of relapsed BCP-ALL.Peer reviewe

DNA Methylation Signatures Predict Cytogenetic Subtype and Outcome in Pediatric Acute Myeloid Leukemia (AML)

Pediatric acute myeloid leukemia (AML) is a heterogeneous disease composed of clinically relevant subtypes defined by recurrent cytogenetic aberrations. The majority of the aberrations used in risk grouping for treatment decisions are extensively studied, but still a large proportion of pediatric AML patients remain cytogenetically undefined and would therefore benefit from additional molecular investigation. As aberrant epigenetic regulation has been widely observed during leukemogenesis, we hypothesized that DNA methylation signatures could be used to predict molecular subtypes and identify signatures with prognostic impact in AML. To study genome-wide DNA methylation, we analyzed 123 diagnostic and 19 relapse AML samples on Illumina 450k DNA methylation arrays. We designed and validated DNA methylation-based classifiers for AML cytogenetic subtype, resulting in an overall test accuracy of 91%. Furthermore, we identified methylation signatures associated with outcome in t(8;21)/RUNX1-RUNX1T1, normal karyotype, and MLL/KMT2A-rearranged subgroups (p < 0.01). Overall, these results further underscore the clinical value of DNA methylation analysis in AML

DNA Methylation Signatures Predict Cytogenetic Subtype and Outcome in Pediatric Acute Myeloid Leukemia (AML)

Pediatric acute myeloid leukemia (AML) is a heterogeneous disease composed of clinically relevant subtypes defined by recurrent cytogenetic aberrations. The majority of the aberrations used in risk grouping for treatment decisions are extensively studied, but still a large proportion of pediatric AML patients remain cytogenetically undefined and would therefore benefit from additional molecular investigation. As aberrant epigenetic regulation has been widely observed during leukemogenesis, we hypothesized that DNA methylation signatures could be used to predict molecular subtypes and identify signatures with prognostic impact in AML. To study genome-wide DNA methylation, we analyzed 123 diagnostic and 19 relapse AML samples on Illumina 450k DNA methylation arrays. We designed and validated DNA methylation-based classifiers for AML cytogenetic subtype, resulting in an overall test accuracy of 91%. Furthermore, we identified methylation signatures associated with outcome in t(8;21)/RUNX1-RUNX1T1, normal karyotype, and MLL/KMT2A-rearranged subgroups (p < 0.01). Overall, these results further underscore the clinical value of DNA methylation analysis in AML