CD40-vermittelte von Willebrand Faktor-Freisetzung aus humanen Endothelzellen

Arteriosklerose ist eine chronisch entzündliche Gefäßerkrankung, deren klinische Manifestationen wie Herzinfarkt, Schlaganfall und Herzinsuffizienz über 40% aller Todesfälle in den westlichen Industrienationen verursachen. Arteriosklerotische Läsionen treten in den großen Arterien, vor allem an Gefäßverzweigungen oder Biegungen auf. In diesen Bereichen herrscht eine niedrige oszillierende Schubspannung bei gleichzeitig verstärkter zyklischer Deformation der Gefäßwand. Die so veränderten hämodynamischen Bedingungen haben eine erhöhte Expression von CD40 in den Endothelzellen zur Folge. Die kostimulatorische Interaktion des CD40-Rezeptors mit seinem Liganden CD154 spielt nicht nur bei der adaptiven Immunantwort, sondern auch bei der Aktivierung von Endothelzellen und der verstärkten Rekrutierung von Entzündungszellen in der Initialphase der Arteriosklerose eine entscheidende Rolle. In dieser Arbeit wurde die Hypothese untersucht, dass die Interaktion von thrombozytärem CD154 mit dem CD40-Rezeptor der Endothelzellen zu einer luminalen Freisetzung des für Thrombozyten hochadhäsiven von Willebrand Faktors (vWF) aus den Endothelzellen führt. Die anschließende Deposition des vWF auf der Endothelzelloberfläche als ultralange vWF-Multimere schafft die Voraussetzung für eine stabile Interaktion zwischen intakten Endothelzellen, Thrombozyten und Leukozyten an den vorgenannten Prädilektionsstellen für die Arteriosklerose und deren Initiierung. In den durchgeführten Experimenten wurden humane, primär kultivierte Endothelzellen sowohl unter niedrigen, oszillatorischen Schubspannungs- als auch unter statischen Bedingungen mit rekombinantem löslichen bzw. zellgebundenem humanen CD154 stimuliert. Diese Stimulation induzierte eine luminale Freisetzung von vWF und eine Fluss-induzierte vWF-Multimer-Bildung auf der Endothelzelloberfläche, die mit Hilfe von Immunfluoreszenzfärbungen visualisiert und mit einem spezifischen ELISA quantifiziert werden konnte. Der nach CD40-Stimulation freigesetzte vWF wies eine starke Assoziation zur Endothelzelloberfläche auf, während Histamin als Kontrollstimulus eine prominente vWFFreisetzung in den Zellüberstand induzierte. Mit Hilfe pharmakologischer Inhibitoren, Western Blot-Analysen und Fura-2-Ratio Imaging bzw. dem Fluo-4-gestützten Nachweis von Veränderungen der intrazellulären Calciumkonzentration konnte gezeigt werden, dass für die CD154-stimulierte Exozytose von vWF aus den Weibel-Palade Körperchen der Endothelzellen ein klassischer calciumabhängiger Signalmechanismus verantwortlich ist. Eine durch CD40-Ligation aktivierte Phosphotyrosinkinase der Src-Familie aktiviert die Phospholipase Cg1, die über die Bildung des sekundären Botenstoffs IP3 Calcium aus dem endoplasmatischen Retikulum freisetzt. Eine Beteiligung der Proteinkinase C und der Proteinkinase A konnte ebenso ausgeschlossen werden wie ein Einstrom von extrazellulärem Calcium durch Ionenkanäle in der Plasmamembran. In isoliert perfundierten Blutgefäßen der Maus führt diese CD154-stimulierte luminale vWF-Freisetzung aus den Endothelzellen tatsächlich zu einer verstärkten Rekrutierung und Aktivierung von Thrombozyten, die ihrerseits Monozyten zu den Zell-Zell-Kontakten der Endothelzellen dirigieren. Da CD154-stimulierte Endothelzellen selbst CD154 exprimieren und dadurch die transmigrierenden Monozyten zu einer Differenzierung zu Makrophagen anregen, könnte diese vWF-verstärkte Endothelzellen-Thrombozyten-Leukozyten- Interaktion in der Tat eine entscheidende Rolle in der Initiierung der Arteriosklerose spielen. Inwieweit sich aus diesen Befunden ein neuer therapeutischer Ansatz zur Vermeidung dieser chronisch-entzündlichen Gefäßerkrankung entwickeln lässt, müssen weiterführende Untersuchungen insbesondere in tierexperimentellen Modellen zeigen

Ökonomische Evaluierung züchterischer Strategien in Weideproduktionssystemen zur Verbesserung der Tiergesundheit und des Tierwohlbefindens

Im Jahr 2010 wurde das Projekt 'WEIDEKUH I' begonnen, welches im Wesentlichen auf der Initiative von milchkuhhaltenden Betrieben basierte und somit von der Praxis an die Wissenschaft herangetragen wurde. Zielsetzung war, für das Produktionssystem 'Weide' die geeignete genetische Grundlage zu identifizieren. Für den Vergleich von unterschiedlichen Holstein Friesian (HF)-Genotypen standen Töchter aus der Anpaarung mit neuseeländischen Bullen und leistungsstarken Milchvererbern sowie für Weidesysteme empfohlenen Bullen aus Deutschland zur Verfügung. Als weitere Vergleichsgruppe diente die Ursprungsrasse der heutigen HF, das Deutsche Schwarzbunte Niederungsrind (DSN). In WEIDEKUH II wurden neben Produktionsmerkmalen aus der routinemäßigen Leistungsprüfung und Merkmalen der Fruchtbarkeit zusätzlich funktionale Merkmale der Tiergesundheit und des Tierwohlbefindens auf den Betrieben erhoben. Diese sind von elementarer Bedeutung für ökologische Zuchtprogramme oder das Züchten in weidebasierten Haltungsverfahren. Die Datenerfassung für eine weite Bandbreite an Merkmalen in Kombination mit einer umfassenden ökonomischen Bewertung der Milchviehhaltung in weidebasierten Produktionssystemen erlaubt a) Untersuchungen zu Genotyp-Umwelt-Interaktionen, b) die Ableitung ökonomischer Gewichte für Produktions- und funktionale Merkmale in Weidesystemen, c) die Entwicklung eines Gesamtzuchtwertes für Weidebetriebe und entsprechende Rangierung von Bullen und d) die Identifizierung von ökonomischen Kriterien für erfolgreiche Milchviehhaltung in weidebasierten Haltungssystemen. WEIDEKUH II ist die Voraussetzung zur Implementierung und Ausdehnung weidebasierter Produktionssysteme in Deutschland. Auf Grundlage der generierten Daten können anhand des entwickelten Gesamtzuchtwertes sowohl der am besten geeignete Genotyp als auch die wertvollsten Bullen über Genotypen hinweg identifiziert werden und betriebliche Strategien zur Maximierung des Betriebsgewinns entwickelt werden

Corrigendum: Abundance and Potential Biological Removal of Common Dolphins Subject to Fishery-Impacts in South Australian Waters

Conservation management of wildlife species should be underpinned by knowledge of their distribution and abundance, as well as impacts of human activities on their populations and habitats. Common dolphins (Delphinus delphis) are subject to incidental capture in a range of Australia’s commercial fisheries including gill netting, purse seining and mid-water trawling. The impact these fishery interactions have on common dolphin populations is uncertain, as estimates of abundance are lacking, particularly for the segments of the populations at risk of bycatch and in greater need of protection. Here we used double-observer platform aerial surveys and mark-recapture distance sampling methods to estimate the abundance of common dolphins in 2011 over an area of 42,438 km2 in central South Australia, where incidental mortality of common dolphins due to fisheries bycatch is the highest. We also used the potential biological removal (PBR) method to estimate sustainable levels of human-caused mortality for this segment of the population. The estimated abundance of common dolphins was 21,733 (CV = 0.25; 95% CI = 13,809–34,203) in austral summer/autumn and 26,504 in winter/spring (CV = 0.19; 95% CI = 19,488–36,046). Annual PBR estimates, assuming a conservative maximum population growth rate of Rmax = 0.02 and a recovery factor of Fr = 0.5 for species of unknown conservation status, ranged from 95 (summer/autumn) to 120 dolphins (winter/spring), and from 189 (summer/autumn) to 239 dolphins (winter/spring) with an Rmax = 0.04. Our results indicate that common dolphins are an abundant dolphin species in waters over the central South Australian continental shelf (up to 100 m deep). Based on the 2011 abundance estimates of this species, the highest estimated bycatch of common dolphins (423 mortalities in 2004/05) in the southern Australian region exceeded the precautionary PBR estimates for this population segment. Recent bycatch levels appear to be below PBR estimates, but low observer coverage and underreporting of dolphin mortalities by fishers means that estimates of dolphin bycatch rates are not robust. The effects of cumulative human impacts on common dolphins are not well understood, and thus we recommend a precautionary management approach to manage common dolphin bycatch based on local abundance estimates

Working With Environmental Noise and Noise-Cancelation: A Workload Assessment With EEG and Subjective Measures

As working and learning environments become open and flexible, people are also potentially surrounded by ambient noise, which causes an increase in mental workload. The present study uses electroencephalogram (EEG) and subjective measures to investigate if noise-canceling technologies can fade out external distractions and free up mental resources. Therefore, participants had to solve spoken arithmetic tasks that were read out via headphones in three sound environments: a quiet environment (no noise), a noisy environment (noise), and a noisy environment but with active noise-canceling headphones (noise-canceling). Our results of brain activity partially confirm an assumed lower mental load in no noise and noise-canceling compared to noise test condition. The mean P300 activation at Cz resulted in a significant differentiation between the no noise and the other two test conditions. Subjective data indicate an improved situation for the participants when using the noise-canceling technology compared to “normal” headphones but shows no significant discrimination. The present results provide a foundation for further investigations into the relationship between noise-canceling technology and mental workload. Additionally, we give recommendations for an adaptation of the test design for future studies

Pygmy blue whale movement, distribution and important areas in the Eastern Indian Ocean

This study was conducted as part of AIMS’ North West Shoals to Shore Research Program (NWSSRP) and was supported by Santos as part of the company’s commitment to better understand Western Australia’s marine environment. Hydrophone pressure data from Ocean Bottom Seismometers (OBS) were provided by the CANPASS project, jointly funded by the National Natural Science Foundation of China (NSFC grants 91955210, 41625016), and the China Academy of Science (CAS program GJHZ1776). Instruments were provided by the Australian National instrument pool ANSIR (http://ansir.org.au/). ANSIR, OBS data was also made data available from the Geoscience Australia and Shell. Data was sourced from Australia’s Integrated Marine Observing System (IMOS).Pygmy blue whales in the South-east Indian Ocean migrate from the southern coast of Australia to Indonesia, with a significant part of their migration route passing through areas subject to oil and gas production. This study aimed at improving our understanding of the spatial extent of the distribution, migration and foraging areas, to better inform impact assessment of anthropogenic activities in these regions. Using a combination of passive acoustic monitoring of the NW Australian coast (46 instruments from 2006 to 2019) and satellite telemetry data (22 tag deployments from 2009 to 2021) we quantified the pygmy blue whale distribution and important areas during their northern and southern migration. We show extensive use of slope habitat off Western Australia and only minimal use of shelf habitat, compared to southern Australia where use of the continental shelf and shelf break predominates. In addition, movement behaviour estimated by a state-space model on satellite tag data showed that in general pygmy blue whales off Western Australia were mostly engaged in migration, interspersed with mostly relatively short periods (median = 28hours, range = 2 – 1080hours) of low move persistence (slow movement with high turning angles), which is indicative of foraging. Using the spatial overlap of time and number of whales in area analysis of the satellite tracking data (top 50% of grid cells) with foraging movement behaviour, we quantified the spatial extent of pygmy blue whale high use areas for foraging and migration. We compared these areas to the previously described areas of importance to foraging and migrating whales (Biologically Important Areas; BIAs). In some cases these had good agreement with the most important areas we calculated from our data, but others had only low (5%) to moderate (13%) overlap. Month was the most important variable predicting the number of pygmy blue whale units and number of singers (acting as indices of pygmy blue whale density). Whale density was highest in the southern part of the NW Australian coast and whales were present there between April-June, and November-December, a pattern also confirmed by the satellite tracking data. Available data indicated pygmy blue whales spent up to 124 days in Indonesian waters (34% of annual cycle). Since this area may also be the calving ground for this population, inter-jurisdictional management is necessary to ensure their full protection.Publisher PDFPeer reviewe

Predictors of the first cardiovascular event in patients with systemic lupus erythematosus - a prospective cohort study

Systemic Lupus Erythematosus (SLE) is an autoimmune, inflammatory disease that mainly affects women. The prognosis of SLE has improved dramatically, but mortality rates are still higher than in the general population. With the improved general prognosis, cardiovascular disease (CVD) has emerged as a major cause of morbidity and mortality among SLE patients. Previous studies have demonstrated that the development of atherosclerosis is accelerated in SLE, and have identified a set of traditional and nontraditional risk factors that characterize SLE patients with CVD. Nevertheless, many unsolved issues with respect to SLE related CVD remain. The general aim of this thesis was to investigate risk factors for manifest CVD and for cardiovascular mortality (CVM) in SLE, with special focus on traditional risk factors, lupus phenotype, inflammatory and endothelial biomarkers, autoantibodies and genetic predisposition. In the first paper, we prospectively studied traditional and non-traditional risk factors for the development of the first cardiovascular event (CVE) in 182 SLE patients with a follow-up time of 8 years. 24(13%) patients had a first event. We demonstrated that of the traditional risk factors, only age and smoking predicted the first CVE. Additionally, antiphospholipid antibodies (aPL), endothelial biomarkers, represented by soluble vascular cell adhesion molecule 1(sVCAM-1), and absence of thrombocytopenia were independent predictors of CVE. Thus, activation of the endothelium and the coagulation system are important features in SLE-related CVD and the importance to advocate smoking cessation among SLE patients is underscored In the second paper, we prospectively investigated causes of mortality and risk factors for overall mortality and CVM in a cohort of 208 SLE patients, with a follow-up time of 12 years. We also evaluated Systematic coronary risk evaluation (SCORE, tool for evaluating the 10 year risk for cardiovascular death in the age span 40-65 years, based on traditional risk factors) in this population. Cystatin C, a sensitive measure of renal function, in addition to traditional and non-traditional risk factors, were evaluated as risk factors. 42 patients died, 48 % of which were due to CVM. Age, previous arterial events and high cystatin C levels were the strongest predictors for overall mortality and for CVM. After adjusting for these three variables, smoking, sVCAM-1 and high sensitiviy C-reactive protein (hsCRP) predicted CVM. SCORE estimated 4 but we observed 9 cases of CVM, a non-significant difference. We conclude that except for smoking, traditional risk factors are less important than cystatin C, endothelial and inflammatory biomarkers as predictors of CVM in SLE patients. In the third paper, we investigated whether a risk allele for SLE in the signal transducer and activator of transcription factor 4 gene (STAT4) was associated with vascular events or presence of antiphospholipid antibodies (aPL). A total of 578 unrelated SLE patients (424 from mid-Sweden and 154 from southern-Sweden) were included in a cross-sectional design. Occurrence of previous cardiovascular events and aPL were tabulated. Matched controls (N=651) were genotyped as a comparison. The results demonstrate that the STAT4 risk allele was associated with ischemic cerebrovascular disease (ICVD), with a dose-dependent relationship between ICVD and number of risk alleles. The risk allele was furthermore associated with the presence of two or more aPLs, also in a dose-dependent manner. The association remained after adjustment for known traditional risk factors. We conclude that patients with the STAT4 risk allele have an increased risk of ICVD. Our results imply that genetic predisposition is an important risk factor for ICVD in SLE patients, and that aPL may be one underlying mechanism. In the fourth paper, we evaluated the potential association between smoking and aPL. 367 SLE patients were investigated in a cross-sectional study. Occurrence of aPL (anticardiolipin (aCL) IgG and IgM, anti-β2 glycoprotein-1 IgG (aβ2GP1 IgG), lupus anticoagulant (LAC)) and smoking habits (never, ever, former, current) were tabulated. Never smoking was used as reference in all calculations. In multivariable models, adjusted for age, sex and age at disease onset, aCL and aβ2GP1 of the IgG isotype and LAC were associated with ever smoking, this association seemed to be driven mainly by the former smoking group. Our results demonstrate that smoking is associated with pro-thrombotic aPL in SLE patients, though we can not from this study draw firm conclusions about the temporal relationship between exposure to smoking and occurrence of aPL. Further studies are warranted to investigate the mechanisms behind these observations. In prospective studies we have demonstrated that in particular smoking, systemic inflammation, endothelial activation and aPL are major risk factors for SLE related CVD and CVM. Furthermore, genetic predisposition, in our studies represented by a STAT4 SLE risk allele, contributes to the high risk of ICVD and to the occurrence of aPL, a possible underlying pathogenic mechanism. Finally we demonstrate that smoking, known to have unfavorable effects on the immune system and to significantly increase cardiovascular risk in SLE patients, is also associated with pro-thrombotic aPL in patients with SLE. Thus in SLE smoking stands out as the most important of the traditional risk factors with potential influence also on lupus related risk factors such as aPL

Melanogenesis is directly affected by metabolites of melatonin in human melanoma cells

Melatonin (N-acetyl-5-methoxytryptamine, MEL), its kynurenic ($N^{1}$-acetyl-$N^{2}$-formyl-5-methoxykynurenine, AFMK) and indolic derivatives (6-hydroxymelatonin, 6(OH)MEL and 5-methoxytryptamine, 5-MT) are endogenously produced in human epidermis. Melatonin, produced by the pineal gland, brain and peripheral organs, displays a diversity of physiological functions including anti-inflammatory, immunomodulatory, and anti-tumor capacities. Herein, we assessed their regulatory effect on melanogenesis using amelanotic (A375, Sk-Mel-28) and highly pigmented (MNT-1, melanotic) human melanoma cell lines. We discovered that subjected compounds decrease the downstream pathway of melanin synthesis by causing a significant drop of cyclic adenosine monophosphate (cAMP) level, the microphthalmia-associated transcription factor (MITF) and resultant collapse of tyrosinase (TYR) activity, and melanin content comparatively to N-phenylthiourea (PTU, a positive control). We observed a reduction in pigment in melanosomes visualized by the transmission electron microscopy. Finally, we assessed the role of G-protein-coupled seven-transmembrane-domain receptors. Obtained results revealed that nonselective MT1 and MT2 receptor antagonist (luzindole) or selective MT2 receptor antagonist (4-P-PDOT) did not affect dysregulation of the melanin pathway indicating a receptor-independent mechanism. Our findings, together with the current state of the art, provide a convenient experimental model to study the complex relationship between metabolites of melatonin and the control of pigmentation serving as a future and rationale strategy for targeted therapies of melanoma-affected patients

Children’s mental health problems and their relation to parental stress in foster mothers and fathers

Lohaus A, Chodura S, Möller C, et al. Children’s mental health problems and their relation to parental stress in foster mothers and fathers. Child and Adolescent Psychiatry and Mental Health. 2017;11(1): 43.Background This study focuses on children living in foster families with a history of maltreatment or neglect. These children often show adverse mental health outcomes reflected in increased externalizing and internalizing problems. It is expected that these adverse outcomes are associated with increased parental stress levels experienced by foster mothers as well as foster fathers. Methods The study sample included 79 children living in foster families and 140 children living in biological families as comparison group. The age of the children ranged from 2 to 7 years. Mental health problems were assessed with the Child Behavior Checklist, while parenting stress was measured with a parenting stress questionnaire including subscales on the amount of experienced stress and the amount of perceived support. The Child Behavior Checklist assessments were based mainly on maternal reports, while the parental stress assessments were based on maternal as well as paternal reports. Results As expected the results showed increased externalizing and internalizing scores for the foster children accompanied by increased parental stress experiences in the foster family sample (however only in the maternal, but not in the paternal stress reports). The stress differences between the foster and biological family groups disappeared, when the children’s mental health problem scores were included as covariates. Moreover, especially the externalizing scores were strong predictors of parental stress in both, the groups of foster and biological parents. The amount of perceived social support was associated with reduced parental stress, but only in the group of biological fathers. Conclusion The emergence of parental stress in biological as well as foster parents is closely related to child characteristics (mainly externalizing child problems). Possible implications for the reduction of parental stress are discussed as a consequence of the present results