16580 research outputs found
Sort by
Untersuchung der NK-Zell-vermittelten Zytotoxizität gegenüber Thymus- und Lebertumorzellen: Einfluss der Chemotherapie und Etablierung eines 3D-Sphäroidmodells
No full textDas Immunsystem des Menschen besteht aus dem angeborenen und dem
erworbenen Teil, die eng miteinander interagieren, sich jedoch in Schnelligkeit und
Spezifität ihrer Reaktion unterscheiden. Natürliche Killerzellen (NK-Zellen) sind Teil
des angeborenen Immunsystems und zeichnen sich durch ihre Fähigkeit aus,
entartete oder virusinfizierte Zellen ohne vorherige Antigenpräsentation zu erkennen
und abzutöten. Ihre Funktion basiert auf einem Gleichgewicht aus inhibitorischen und
aktivierenden Rezeptorsignalen, wobei ein Verlust der MHC-I-Expression auf
Zielzellen zu ihrer Aktivierung führt. NK-Zellen eliminieren Zielzellen vor allem durch
Freisetzung zytotoxischer Granula, die Apoptose-induzierende Signalwege aktivieren.
Im Kontext der Tumorimmunologie gewinnen NK-Zellen zunehmend an Bedeutung,
da sie über das Potenzial verfügen, nicht nur Primärtumoren, sondern auch
Metastasen effektiv zu bekämpfen. Bereits in den 1970er-Jahren wurde ihre Rolle in
der immunologischen Tumorüberwachung erkannt. Angesichts steigender
Krebsinzidenzen in industrialisierten Ländern und der Fähigkeit von Tumorzellen, dem
Immunsystem zu „entgehen“, rückt die Entwicklung NK-Zell-basierter Immuntherapien
zunehmend in den Fokus. Aufgrund dieser Eigenschaften gelten NK-Zellen als
vielversprechender Bestandteil zukünftiger immuntherapeutischer Strategien in der
Onkologie.
Ziel dieser Dissertation war es, die bisherigen Erkenntnisse zur anti-tumoralen Aktivität
von NK-Zellen zu erweitern. Im Zentrum der experimentellen Untersuchungen stand
die Analyse des Einflusses von NK-Zellen auf die Viabilität von Tumorzellen in einem
etablierten Koinkubationsmodell. Dabei wurden sowohl das Ausmaß der durch NK-
Zellen vermittelten Zytotoxizität als auch die Induktion apoptotischer Prozesse mittels
durchflusszytometrischer Verfahren untersucht. Zudem sollte die Expression des
Poliovirusrezeptors (PVR), der die Proliferation und Invasion von Krebszellen fördert,
auf Tumorzellen sowie seine Modulation im Kontakt mit NK-Zellen analysiert werden.
Ein weiterer Schwerpunkt lag auf der Evaluierung möglicher synergistischer Effekte
zwischen den Anti-Tumoraktivitäten von ausgewählten Chemotherapeutika bei
anschließender Inkubation der Tumorzellen mit NK-Zellen. Auch die Auswirkungen
einer Glukosereduzierung im Tumormedium auf die NK-Zell-vermittelte Zytotoxizität
sollten näher betrachtet werden. Hierbei sollte überprüft werden, ob eine kombinierte
Anwendung die antitumorale Wirksamkeit der NK-Zellen gegenüber den verwendeten
Tumorzelllinien gesteigert werden kann. Ergänzend dazu wurde die Etablierung eines
dreidimensionalen Tumormodells auf Sphäroidbasis angestrebt, um zukünftig
physiologisch relevantere Bedingungen für weiterführende Analysen zu schaffen. Für
sämtliche Untersuchungen kamen die Tumorzelllinien HepG2 und TY82 zum Einsatz.
Die Auswertung der Versuchsergebnisse zeigt deutlich, dass eine Koinkubation mit
NK-Zellen zu einer signifikanten Reduktion der Tumorzellviabilität führte, vor allem
durch die Induktion von Apoptose. Bei den HepG2-und TY82-Zellen wurde bereits in
der frühen Interaktionsphase eine ausgeprägte zytotoxische Aktivität beobachtet,
122
Zusammenfassung
begleitet von einer schnellen NK-Zell-Aktivierung (Degranulation) und einer erhöhten
GLUT-1-Expression. Die getestete Kombinationstherapie mit Chemotherapeutika
(Etoposid, Cisplatin) führte zu keinen synergistischen Effekten. Es deutet im Gegenteil
auf mögliche negative Wechselwirkungen hin, was die Notwendigkeit einer
sorgfältigen Optimierung hinsichtlich Dosis und zeitlicher Abfolge betont. Darüber
hinaus zeigte der PARP-Inhibitor Olaparib, der zur Behandlung von Ovarialkarzinomen
verwendet wird, nur eine begrenzte immunmodulatorische Wirkung in frühen Phasen
der Koinkubation, aber ebenfalls keinen synergistischen Effekt. Der beobachtete
Zelluntergang ab 48 Stunden legt nahe, dass weitere Studien zur Rolle nicht-
apoptotischer Zelltodmechanismen wie Parthanatos erforderlich sind. Weitere
Modalitäten während des Versuches, wie eine unterschiedliche
Glukosekonzentrationen im Kulturmedium hatten keinen signifikanten Einfluss auf die
NK-Zell-vermittelte Zytotoxizität. Ebenso wurde in beiden Zelllinien ein Rückgang der
PVR-Expression nach NK-Zell-Kontakt festgestellt, wobei dieser bei HepG2 statistisch
signifikant war und einen direkten regulatorischen Effekt vermuten lässt. Abschließend
konnten erfolgreich dreidimensionale Tumorsphäroide aus TY82- und HepG2-Zellen
etabliert werden, die ein valides präklinisches Modell zur weiterführenden
Untersuchung der NK-Zell-basierten Immuntherapie darstellen.
Aus den Ergebnissen dieser Arbeit geht hervor, dass der direkte Kontakt mit
Tumorzellen zu einer signifikanten Steigerung der zytotoxischen Aktivität von NK-
Zellen führte, insbesondere gegenüber der soliden Tumorzelllinie TY82. Da
Immuntherapien bislang vor allem bei hämatologischen Neoplasien Erfolge
verzeichnen, während ihre Wirksamkeit bei soliden Tumoren als limitiert gilt, ist dieser
Befund von besonderer Relevanz. Die beobachtete Empfindlichkeit der
Chemotherapie-resistenten TY82-Zelllinie gegenüber NK-Zell-vermittelter Zytotoxizität
deutet auf ein potenzielles therapeutisches Fenster hin und unterstreicht die
Bedeutung der NK-Zellen als vielversprechende Option in der Behandlung solider
Tumoren
Metabolic rewiring and HIF1α accumulation upon Rnf20 loss result in lung cancer progression
No full textDuring my PhD research, I investigated the role of RNF20 loss in the initiation, development, and progression of lung cancer. Rnf20 haploinsufficiency in mice led to a marked increase in tumor incidence, which was accompanied by elevated DNA damage and a reduction in the tumor suppressors p53 and Rb1. These findings were further corroborated in vitro using control and Rnf20+/- lung epithelial cells, where transcriptomic analysis revealed significant upregulation of genes involved in cell migration, extracellular matrix organization, metabolic pathways, and the HIF-1 signaling pathway following RNF20 loss.
To explore the impact of RNF20 on cellular metabolism, I conducted metabolomic assays, which showed that Rnf20 deficiency enhances glycolytic capacity and increases TCA cycle metabolite levels. Integrating RNA-seq with metabolomic profiling, I found that the genes upregulated in Rnf20+/- cells were closely associated with glycolytic metabolism. Importantly, through Hif1α knockdown and glycolysis inhibition, I demonstrated that HIF1α mediates both metabolic reprogramming and tumor-promoting effects in the context of RNF20 loss. Mechanistically, Pol II ChIP-seq revealed that RNF20 loss promotes RNA polymerase release at HIF1α target genes and EMT markers, contributing to transcriptional activation. In contrast, ChIP-seq for H2Bub1 and H3K4me3 showed that genes downregulated upon RNF20 loss were more closely associated with loss of histone ubiquitination rather than changes in Pol II dynamics, suggesting distinct regulatory mechanisms. Further analysis uncovered that the accumulation of HIF1α upon RNF20 loss is likely due to the downregulation of RBX1, a key component of the E3 ubiquitin ligase complex responsible for HIF1α degradation. Additionally, I observed functional divergence between RNF20 and RNF40, despite their role in the same ubiquitin ligase complex, indicating distinct roles in lung cancer progression.
In summary, my study demonstrated that RNF20 acts as a tumor suppressor in lung cancer, and its expression is significantly reduced in patient samples, correlating with poor clinical outcomes. RNF20 loss drives lung tumorigenesis through epigenetic deregulation of metabolic genes, particularly via HIF1α-mediated transcriptional and metabolic reprogramming. However, the key question remains: what causes RNF20 downregulation in lung cancer? Given the strong link between environmental exposures such as smoking and air pollution and lung cancer risk, these factors may contribute to RNF20 suppression. Future studies aimed at understanding the regulatory mechanisms governing RNF20 expression could provide valuable insights into early detection, risk assessment, and targeted therapeutic strategies for lung cancer
From Radiation Track to DNA Damage: The Biophysics Behind Alpha- and Beta-Minus-Emitters in Targeted Radionuclide Therapy
No full textMetastatic cancer remains a major challenge, necessitating innovative treatments like Targeted Radionuclide Therapy (TRT). Understanding the underlying radiobiological mechanisms influenced by radionuclide type, administered activity, and cellular localization is of utmost importance for optimizing TRT effectiveness and combating radioresistance. This study uses the prostate cancer-addressing radiopharmaceutical PSMA-617 to investigate how the physical differences between clinically-used alpha-emitter Ac-225 and beta-minus-emitter Lu-177 affect radiobiological efficacy and therapeutic outcome. Immunofluorescent gamma-H2AX staining of DNA double-strand breaks (DSBs) and cell proliferation assays demonstrated that the alpha-emitter outperformed the beta-minus-emitter, achieving a similar amount of DSBs with only 1 per cent of the activity. Notably, targeted internalization significantly enhanced therapeutic efficacy of short-range alpha-emitters (47–85 μm), while having negligible impact for longer-range beta-minus-emitters (1.5–1.7mm). Furthermore, the amount of alpha-induced DSBs remained high for up to 72 hours, while it decreased for beta-minus-exposure and external photon irradiation. Combining TRT with the DNA-PK inhibitor Nedisertib further enhanced treatment efficacy and demonstrated resistance-overcoming potential, allowing for a reduction in activity even at low inhibitor concentrations. These findings underscore the importance of radiobiology in TRT and highlight the relevance of alpha-emitters as well as combination strategies for more effective and well-tolerated cancer treatments
Peritonealflap zur Prophylaxe von Lymphozelen nach laparoskopischer, robotisch-assistierter, radikaler Prostatektomie mit pelviner Lymphknotendissektion
No full textSymptomatische Lymphozelen als häufigste postoperative Komplikation nach
transperitonealer robotisch-assistierter radikaler Prostatektomie mit pelviner
Lymphadenektomie stellen eine Belastung hauptsächlich für die Patienten aber auch das Gesundheitssystem dar. Prospektive Daten zur Prophylaxe von Lymphozelen mittels Peritonealflap zwischen der Harnblase und Region der pelvinen Lymphadenektomie waren zu Beginn der Promotion / Studienbeginn nicht vorhanden. Ziel der Studie war es, die Überlegenheit des Peritonealflaps in der Reduktion symptomatischer Lymphozelen nachzuweisen.
Die PELYCAN Studie ist eine prospektive, stratifizierte, adaptive, randomisierte,
doppelverblindete, monozentrische Überlegenheitsstudie der Phase III mit
publiziertem Studienprotokoll. Alle Studienteilnehmer mit bioptisch nachgewiesenem Prostatakarzinom wurden zwischen September 2019 und Dezember 2021 nach bekannten und potenziellen Risikofaktoren (extendierte pelvine Lymphadenektomie, Diabetes mellitus, Antikoagulation), eine Lymphozele auszubilden, und Operateur stratifiziert sowie in einem Zuteilungsverhältnis von 1:1 der Interventions- oder Kontrollgruppe durch Blockrandomisierung (Blöcke mit variierender Länge) zugeordnet. Mit Fertigstellung der vesicourethralen Anastomose, ein operativer Schritt
der robotisch-assistierten radikalen Prostatektomie, erfuhr der Operateur das Ergebnis der Randomisierung und legte in der Interventionsgruppe den bilateralen Peritonealflap an. Das ventrale Peritoneum wurde in der Interventionsgruppe auf beiden Seiten seitlich eingeschnitten, um die Peritonealflaps anzulegen. Diese wurden mit zwei Einzelknopfnähten am Beckenboden lateral der Harnblase gegenüber der Region der
pelvinen Lymphadenektomie fixiert. Als primärer Endpunkt fungierten symptomatische Lymphozelen mit der Notwendigkeit einer Drainageeinlage innerhalb einer sechsmonatigen Nachbeobachtung. Zu den
sekundären Endpunkten zählten asymptomatische Lymphozelen, Lymphödeme, Erysipele, tiefe Venenthrombosen, perioperative Parameter, Krankenhaus-
verweildauer, postoperative Komplikationen und Lebensqualität.
Eine signifikante Reduktion sowohl symptomatischer (von 9,1 % auf 3,7 %) als auch asymptomatischer Lymphozelen (von 16,8 % auf 7,4 % am Entlasstag; von 27,2 % auf 10,3 % während des Follow-ups) wurde in der Interventionsgruppe beobachtet. Nach Exklusion der Lymphozelen und Lymphozelen-assoziierten Komplikationen unterschieden sich Schweregrad und Anzahl der postoperativen Komplikationen zwischen den Gruppen nicht signifikant. Der Peritonealflap modifiziert die robotisch-assistierte radikale Prostatektomie mit pelviner Lymphadenektomie einfach, kostengünstig und sicher, sodass signifikant weniger (a)symptomatische Lymphozelen entstehen. Deshalb sollte der Peritonealflap zum neuen Standard im Rahmen der transperitonealen RARP mit PLND werden
Search for B(c)+ → μ+νγ decays with the LHCb experiment and upgrade of the electromagnetic calorimeter
No full textKnowledge of the internal structure of the B+ meson is crucial for precise theory predictions of B+ meson decays. In particular, the first inverse moment of the B+-meson light-cone distribution amplitude (LCDA) is a key ingredient in QCD factorisation schemes. Inferring the value of the first inverse moment from theory models is very challenging and often limits the precision of theory predictions. Instead, it is proposed to infer its value from experimental data.
The radiative leptonic decay B+ → µ+νγ is considered the golden mode to probe the internal structure of the B+ meson, as its branching fraction is sensitive to the first inverse moment of the B+-meson LCDA. Studies of radiative leptonic decays of Bc+ mesons, on the other hand, allow to infer the dynamics in the bound Bc+ meson system.
This thesis presents the simultaneous search for B+ → µ+νγ and Bc+ → µ+νγ decays using data recorded with the LHCb experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV from 2016 to 2018, corresponding to an integrated luminosity of 5.4 fb−1 . The decays are reconstructed from photons converting to di-electron tracks in the detector material, which provide three tracks and a displaced decay vertex. The main challenge is to identify and suppress background from π0 → γγ decays, for which novel techniques are developed. The study aims to improve the current best limit on the branching fraction for B+ → µ+νγ decays
and set the first limit on the branching fraction for Bc+ → µ+νγ decays. The expected limits on the branching fractions for radiative leptonic decays are of the order of 10−6 for decays of B+ mesons and 10−4 for the decay of Bc+ mesons.
With the LHCb experiment aiming to collect data at higher instantaneous luminosities in future runs, the detector is upgraded. This thesis reports on the organisation of the cabling of the electromagnetic calorimeter and presents performance studies of the particle identification system for Run 4 for different upgrade scenarios
Forces and Transport in Biological Media
No full textForces are fundamental to the function of living systems, driving natural processes such as tissue morphogenesis and locomotion, as well as our ability to interact with living matter, for instance, in the context of therapeutic interventions. Magnetic fields, in particular, offer distinct advantages in biomedical applications due to their ability to penetrate tissues non-invasively and exert forces remotely. Beyond delivering mechanical stimuli, magnetic fields can facilitate the transport of objects through biological media.
This work spans several approaches to generate forces using magnetism at the nano- and microscale, including magnetic field gradients, rotating magnetic fields, and homogeneous magnetic fields. These strategies are applied in various biomedical contexts to enable characterization, manipulation, and transport of nano- and microscale objects. Furthermore, when direct mechanical forces alone are insufficient to achieve the desired outcomes, the thesis investigates an alternative strategy to locally disrupt a principal biological barrier, thereby facilitating transport within complex biological environments.
The thesis begins with a quantitative analysis of the force ranges achievable through different magnetic strategies and their implications for biomedical applications. Subsequently, a method is developed to quantify the magnetic properties of individual particles suspended in liquid using magnetic field gradients. Magnetic stimuli are then applied to cells with the aim of developing tools to investigate mechanotransduction. In this context, cell monolayers are mechanically stimulated using embedded ferrofluid droplets, which serve as magnetically responsive actuators under homogeneous magnetic fields. This platform is subsequently enhanced by introducing a magnetizable probe that locally perturbs the uniform magnetic field, thereby generating spatially confined magnetic field gradients at the microscale. A similar microscale gradient strategy is employed in a separate experimental setup to guide the sprouting of cells that have internalized magnetic nanoparticles, offering a tool for applications in tissue engineering. The final section of the thesis explores the transport of nano- and microscale objects for ophthalmological applications, with the aim of enabling targeted delivery of drugs or therapeutic genes within the eye. The work first addresses transport through potential vitreous substitutes, which are relevant in the treatment of eye conditions. Using magnetic field gradients, suitable hyaluronic acid–based formulations are identified that permit the penetration of nano- and microparticles. Building on these findings, the thesis demonstrates the active propulsion of helical nano- and micropropellers within these materials using rotating magnetic fields, thereby establishing the feasibility of magnetically guided delivery systems in hydrogels that are designed to replace the vitreous body. Finally, the thesis investigates targeted nanoscale transport to retinal cells, where the successful delivery of therapeutic genes holds promise for treating a range of retinal disorders that can lead to blindness. Initial experiments using ex vivo porcine models are used to asses the property of natural barriers impeding nanoscale transport. To address limited permeability, a more refined strategy is introduced, in which enzymes are attached to microparticles to enable localized degradation of the primary biological barrier, thereby facilitating access to the retina. This approach results in enhanced nanoparticle transport across the barrier.
Collectively, this work establishes methods for magnetic-field based force application, targeted manipulation, and controlled transport at the nano- and microscale within complex biological environments. This work introduces novel tools and strategies that advance both mechanobiology and targeted ocular delivery systems
Elucidating the Singlet Fission Mechanism with Time-Resolved Multi-Dimensional Spectroscopies
No full textSinglet fission (SF) can enhance light-conversion efficiencies by splitting high-energy photons
into multiple low-energy triplet excitons, preserving otherwise lost energy due to thermalization.
This can potentially improve efficiencies by 30% relative to the Shockley-Queisser limit in
single-junction solar cells, driving extensive research into suitable sensitizer materials. A
bottleneck of research is that strong coupling promotes efficient SF but also hinders separation
of generated triplets. Striking just the right balance is challenging, due to the multitude of
factors that may affect the sensitizers’ SF capabilities. Moreover, the presence of multiple dark
states in the initial stages of SF complicates its experimental evaluation in regards to those
critical factors.
This thesis aims to address these challenges by studying the impact of targeted system
modifications on the SF mechanism under weak coupling conditions using time-resolved
spectroscopic methods, such as transient absorption (TA) and two-dimensional electronic
spectroscopy (2DES). For example, the feasibility of intermolecular SF is studied in a
pentacene derivate, where acene faces are shielded with additional phenylene functional
groups that restrict interaction between chromophores. While SF is not observed in solution,
thin films of the materials dispersed in polymer matrices show SF rates (kSF) that follow a
Förster resonance energy transfer (FRET) scaling with the average chromophore separation
(R): kSF ∝ R-6
. In turn, the excitation-energy transfer (EET) mechanism acts as the rate-limiting
step to SF and enhances it in a similar fashion to how natural light-harvesting networks improve
energy flow in proteins: Singlet excitons are funneled by FRET to SF-reaction sites where it
can proceed with near-unity quantum yields.
More attention is directed towards intramolecular SF (i-SF) in spiro-linked dimers, consisting
of two modifiable chromophores covalently bound to a spiro-carbon linker. Through spectral
reconstruction and semi-classical simulations of 2DES signal responses, it is shown that the
linker provides a framework of weak coupling that is still strong enough to enable efficient i-SF.
Dimerization of two dissimilar chromophores into heterodimers finely and predictively tunes
the energetic driving force of i-SF, which shown to have a great impact on its rate and
efficiency. Hetero-oligomerization proves especially effective in furnishing i-SF sensitizers that
show improved triplet yields (≈174% yield for separated triplets) compared to their homodimeric counterparts, facilitated also by downhill EET. Direct control over the excitonic coupling
responsible for i-SF is achieved by additionally linking the individual chromophores via
molecular bridges; by modulating the dihedral geometry of chromophores, the strength of their
intramolecular coupling is directly affected. How this chemical modification translates to
changes in the excitonic coupling, and in turn, the i-SF process, is evaluated experimentally
II
using transient 2DES, which was implemented during this work. Through this advanced
spectroscopic method, a primarily direct i-SF mechanism is concluded for when chromophores
are in closer proximity. As the chromophores are further separated by insertion of molecular
bridges, direct i-SF becomes increasingly suppressed in favor of a super-exchange mediated
i-SF mechanism and the overall rate and efficiency of the excited-state process decreases.
Obtaining such high levels of mechanistic detail is usually reserved to theoretical studies, which
has been made possible by utilizing the extraordinaire selectivity of transient 2DES towards
excited state transitions, opening up the avenue to study SF or other excited-state phenomena
with unprecedented detail. Altogether, this thesis lays out the impact of excitonic coupling
(through dimer geometries), energetic driving force (through alterations of chemical
compositions), and excitation energy transfer on the outcome of singlet fission, understood
through the lens of multiple time-resolved spectroscopies. As demonstrated here, these
properties of nature act synergistically and can be utilized to improve the efficiency of (i-) SF,
providing insight into molecular design principles for organic materials intended for applications
in solar energy technologies
TIR-domain-containing protein C of uropathogenic E. coli CFT073 as a modulator of innate immune checkpoints
No full textUrinary tract infections are one of the most common community-acquired infections worldwide, affecting approximately 150 million people each year. Uropathogenic E. coli are responsible for the vast majority of UTIs. In order to infect the lower and upper urinary tract, they express a wide variety of virulence factors. One of these virulence factors is TcpC, a Toll/interleukin-1 receptor domain-containing protein produced by various E. coli strains of the phylogenetic group B2, including CFT073. Studies have shown that TcpC is able to inhibit TNFα and IL-1β release of mouse macrophages during an infection with E. coli CFT073. It is suggested that TcpC is able to inhibit cytokine release of these cells by binding to specific proteins of the TLR4 signaling cascade and the NLRP3 inflammasome.
I now report that TcpC is able to stimulate cytokine release of immune and bladder epithelial cells during infection. Human monocytes and human bladder epithelial cells release higher amounts of proinflammatory cytokines after infection with TcpC-producing CFT073 strains compared to a TcpC knockout. Differentiation of monocytes to macrophages abrogates this TcpC-dependent effect. Infection of T24/83ΔTLR4 cells suggests that exclusively TLR4 is responsible for a proinflammatory reaction. Furthermore, infection of T24/83ΔMyD88 bladder epithelial cells suggests that the TcpC-induced stimulation of proinflammatory cytokines is MyD88-independent. THP-1 cells treated with conditioned medium in which TcpC was overexpressed at different levels showed that TcpC inhibited cytokine release after stimulation with LPS plus ATP at low levels of induction. Deletion of the TIR-domain of TcpC leads to a loss of the inhibitory capabilities, showing that it is crucial for the function of the protein in this context.
Thus, during an infection of monocytes with CFT073, the proinflammatory response is increased compared to the TcpC knockout strain, whereas treatment with culture supernatants containing TcpC inhibits the proinflammatory response of LPS plus ATP stimulated monocytes. In summary, I conclude that the TcpC-induced inhibition versus stimulation of release of proinflammatory cytokines may depend on the direct contact between CFT073 and eukaryotic cells. Since TcpC is able to bind to TLR4 and MyD88, I think it affects myddosome formation after stimulation of cells with LPS, which may be further influenced by the direct contact of the bacterium with the immune cells
Nietzsches nihilistische Ontologie
No full textIm Frühjahr 1887 zeichnet Friedrich Nietzsche den folgenden Gedanken auf: „Dem Werden den Charakter des Seins aufzuprägen – das ist der höchste Wille zur Macht.“ Handelt es sich hierbei um eine, gar die grundlegende ontologische Einsicht des Philosophen, um die entscheidende Verhältnis-bestimmung zwischen Sein, Werden und Wille zur Macht? Welchen Status und Rang besitzt die Charakterlehre im Hinblick auf Sein und Werden, Denken und Realität, Wille zur Macht und Ewige Wiederkunft, Wert und Nihilismus? Es ist vielversprechend, den Aussagen der Notiz nachzugehen, ihrer Vorgeschichte, ihren Hintergründen, Voraussetzungen, Beziehungen und Konsequenzen, ihrem Gewicht und den Fragen, die sich aus ihnen ergeben