A type I IFN-dependent DNA damage response regulates the genetic program and inflammasome activation in macrophages

Macrophages produce genotoxic agents, such as reactive oxygen and nitrogen species, that kill invading pathogens. Here we show that these agents activate the DNA damage response (DDR) kinases ATM and DNA-PKcs through the generation of double stranded breaks (DSBs) in murine macrophage genomic DNA. In contrast to other cell types, initiation of this DDR depends on signaling from the type I interferon receptor. Once activated, ATM and DNA-PKcs regulate a genetic program with diverse immune functions and promote inflammasome activation and the production of IL-1β and IL-18. Indeed, following infection with Listeria monocytogenes, DNA-PKcs-deficient murine macrophages produce reduced levels of IL-18 and are unable to optimally stimulate IFN-γ production by NK cells. Thus, genomic DNA DSBs act as signaling intermediates in murine macrophages, regulating innate immune responses through the initiation of a type I IFN-dependent DDR.</jats:p

Das Auftreten der 4977 bp Deletion in Blut, Milz, Knochenmark und Skelettmuskel

Die 4977 bp Deletion (common deletion) ist die häufigste Deletion der mitochondrialen DNA. Ihr Auftreten wurde in vielen Vorarbeiten in verschiedenen Geweben detektiert. In dieser Arbeit wurde die Deletion im Gegensatz zu vielen Vorarbeiten bereits bei Personen unter 20 Jahren nachgewiesen. Dies gelang für alle untersuchen Gewebe (Milz, Knochenmark, Skelettmuskel und Blut). Mit dieser Untersuchung sollte überprüft werden, ob das Auftreten der 4977 bp Deletion als Prozess des Alterns selbst zu verstehen ist. Dies konnte nicht nachgewiesen werden. Lediglich im Skelettmuskelgewebe fand sich mit zunehmendem Alter ein relevanter Anstieg der 4977 bp Deletion. Wohingegen das relative Verhältnis von mitochondrialer DNA zur nukleären DNA konstant blieb. Für die untersuchten Blutproben ergaben sich ähnliche Ergebnisse. Es kam hier zu einer geringen Zunahme der Deletion im Bezug auf das Lebensalter, jedoch auch zu einer geringen Zunahme der mitochondrialen DNA bezüglich der nukleären DNA. Für Milz und Knochenmark konnte keine altersabhängige Zunahme der 4977 bp Deletion gefunden werden. Vielmehr zeigte sich, dass vermutlich ein vermehrtes Auftreten der 4977 bp Deletion schon in den Stammzellen und Vorläuferzellen ein vermehrtes Auftreten der Deletion im ausdifferenzierten Gewebe nach sich zog. In dieser Arbeit ist zu bemerken, dass das Extraktionverfahren keinen Einfluss auf die Qualität und die relative Quantität der dmtDNA, mtDNA und nDNA hat. Die 4977 bp- Deletion ist somit weniger als Alterungsprozess zu verstehen, vielmehr als Folge von verschiedenen Einflussfaktoren. Viele Arbeiten haben den Einfluss von exogenen Faktoren untersucht. Am wichtigsten scheint der Einfluss von oxidativen Prozessen auf das Auftreten der 4977 bp Deletion zu sein. Gründe hierfür sind die räumliche Nähe zu den oxidativen Prozessen der Mitochondrienmembran und die im Vergleich zu der nukleären DNA weniger ausgefeilten Reparaturmechanismen. Interindividuelle Unterschiede ergeben sich durch den Lifstyle (Alkohol- und Zigarettenkonsum) und individuellen Stress

Stage-specific proteomes from onchocerca ochengi, sister species of the human river blindness parasite, uncover adaptations to a nodular lifestyle

Despite 40 years of control efforts, onchocerciasis (river blindness) remains one of the most important neglected tropical diseases, with 17 million people affected. The etiological agent, Onchocerca volvulus, is a filarial nematode with a complex lifecycle involving several distinct stages in the definitive host and blackfly vector. The challenges of obtaining sufficient material have prevented high-throughput studies and the development of novel strategies for disease control and diagnosis. Here, we utilize the closest relative of O. volvulus, the bovine parasite Onchocerca ochengi, to compare stage-specific proteomes and host-parasite interactions within the secretome. We identified a total of 4260 unique O. ochengi proteins from adult males and females, infective larvae, intrauterine microfilariae, and fluid from intradermal nodules. In addition, 135 proteins were detected from the obligate Wolbachia symbiont. Observed protein families that were enriched in all whole body extracts relative to the complete search database included immunoglobulin-domain proteins, whereas redox and detoxification enzymes and proteins involved in intracellular transport displayed stage-specific overrepresentation. Unexpectedly, the larval stages exhibited enrichment for several mitochondrial-related protein families, including members of peptidase family M16 and proteins which mediate mitochondrial fission and fusion. Quantification of proteins across the lifecycle using the Hi-3 approach supported these qualitative analyses. In nodule fluid, we identified 94 O. ochengi secreted proteins, including homologs of transforming growth factor-β and a second member of a novel 6-ShK toxin domain family, which was originally described from a model filarial nematode (Litomosoides sigmodontis). Strikingly, the 498 bovine proteins identified in nodule fluid were strongly dominated by antimicrobial proteins, especially cathelicidins. This first high-throughput analysis of an Onchocerca spp. proteome across the lifecycle highlights its profound complexity and emphasizes the extremely close relationship between O. ochengi and O. volvulus The insights presented here provide new candidates for vaccine development, drug targeting and diagnostic biomarkers

Original Contribution 2 PGD 2 and PGE 2 regulate gene expression of Prx 6 in primary macrophages via Nrf2

Prostaglandin 26 Free radicals 27 Peroxiredoxin 6 (Prx 6) is a bifunctional enzyme with both glutathione peroxidase and acidic Ca 2+ -28 independent phospholipase A 2 activities. We have recently shown that exposure of murine bone marrow-29 derived macrophages to LPS and IFN-γ leads to induction of COX-2 expression and secretion of PGE 2 , up-30 regulating Prx 6 mRNA levels. This study was designed to investigate various prostaglandins (PGs) for their 31 ability to induce gene expression of Prx&apos;s, in particular Prx 6, and to determine the underlying regulatory 32 mechanisms. We provide evidence that both conventional and cyclopentenone PGs enhance Prx 6 mRNA 33 expression. Treatment with either activators or inhibitors of adenylate cyclase as well as cAMP analogs 34 indicated that Prx 6 gene expression is regulated by adenylate cyclase in response to PGD 2 or PGE 2 . 35 Furthermore, our study revealed that JAK2, PI3K, PKC, and p38 MAPK contribute to the PGD 2 -or PGE 2 -36 dependent Prx 6 induction. Using stimulated macrophages from Nrf2-deficient mice or activators of Nrf2 and 37 PPARγ, we found that Nrf2, but not PPARγ, is involved in the PG-dependent increase in Prx 6 mRNA 38 expression. In summary, our data suggest multiple signaling pathways of Prx 6 regulation by PGs and 39 identified Nrf2 as a critical player mediating transcriptional induction. 40 © 2011 Elsevier Inc. All rights reserved

High-Dose Chemotherapy Followed by Autologous Stem Cell Transplantation for Metastatic Rhabdomyosarcoma—A Systematic Review

INTRODUCTION: Patients with metastatic rhabdomyosarcoma (RMS) have a poor prognosis. The aim of this systematic review is to investigate whether high-dose chemotherapy (HDCT) followed by autologous hematopoietic stem cell transplantation (HSCT) in patients with metastatic RMS has additional benefit or harm compared to standard chemotherapy. METHODS: Systematic literature searches were performed in MEDLINE, EMBASE, and The Cochrane Library. All databases were searched from inception to February 2010. PubMed was searched in June 2010 for a last update. In addition to randomized and non-randomized controlled trials, case series and case reports were included to complement results from scant data. The primary outcome was overall survival. A meta-analysis was performed using the hazard ratio as primary effect measure, which was estimated from Cox proportional hazard models or from summary statistics of Kaplan Meier product-limit estimations. RESULTS: A total of 40 studies with 287 transplant patients with metastatic RMS (age range 0 to 32 years) were included in the assessment. We identified 3 non-randomized controlled trials. The 3-year overall survival ranged from 22% to 53% in the transplant groups vs. 18% to 55% in the control groups. Meta-analysis on overall survival in controlled trials showed no difference between treatments. Result of meta-analysis of pooled individual survival data of case series and case reports, and results from uncontrolled studies with aggregate data were in the range of those from controlled data. The risk of bias was high in all studies due to methodological flaws. CONCLUSIONS: HDCT followed by autologous HSCT in patients with RMS remains an experimental treatment. At present, it does not appear justifiable to use this treatment except in appropriately designed controlled trials

Onchocerciasis (river blindness) – more than a century of research and control

This review summarises more than a century of research on onchocerciasis, also known as river blindness, and its control. River blindness is an infection caused by the tissue filaria Onchocerca volvulus affecting the skin, subcutaneous tissue and eyes and leading to blindness in a minority of infected persons. The parasite is transmitted by its intermediate hosts Simulium spp. which breed in rivers. Featured are history and milestones in onchocerciasis research and control, state-of-the-art data on the parasite, its endobacteria Wolbachia, on the vectors, previous and current prevalence of the infection, its diagnostics, the interaction between the parasite and its host, immune responses and the pathology of onchocerciasis. Detailed information is documented on the time course of control programmes in the afflicted countries in Africa and the Americas, a long road from previous programmes to current successes in control of the transmission of this infectious disease. By development, adjustment and optimization of the control measures, transmission by the vector has been interrupted in foci of countries in the Americas, in Uganda, in Sudan and elsewhere, followed by onchocerciasis eliminations. The current state and future perspectives for control, elimination and eradication within the next 20–30 years are described and discussed. This review contributes to a deeper comprehension of this disease by a tissue-dwelling filaria and it will be helpful in efforts to control and eliminate other filarial infections