University of Wuerzburg

Circadian master clocks in the brain consist of multiple neurons that are organized into populations with different morphology, physiology, and neuromessenger content and presumably different functions. In most animals, these master clocks are distributed bilaterally, located in close proximity to the visual system, and synchronized by the eyes with the light-dark cycles of the environment. In mammals and cockroaches, each of the two master clocks consists of a core region that receives information from the eyes and a shell region from which most of the output projections originate, whereas in flies and several other insects, the master clocks are distributed in lateral and dorsal brain regions. In all cases, morning and evening clock neurons seem to exist, and the communication between them and other populations of clock neurons, as well as the connection across the two brain hemispheres, is a prerequisite for normal rhythmic function. Phenomena such as rhythm splitting, and internal desynchronization are caused by the "decoupling" of the master clocks in the two brain hemispheres or by the decoupling of certain clock neurons within the master clock of one brain hemisphere. Since the master clocks in flies contain relatively few neurons that are well characterized at the individual level, the fly is particularly well suited to study the communication between individual clock neurons. Here, we review the organization of the bilateral master clocks in the fly brain, with a focus on synaptic and paracrine connections between the multiple clock neurons, in comparison with other insects and mammals.

Bumble bees are important pollinators of crops in the field and greenhouses. They are naturally exposed to a combination of interacting stressors, e.g., loss of flowering resources and exposure to plant protection products. Mass-flowering crops are important resources for bees, but they may result in unbalanced nutrition due to different nutritional values. In this study, a semi-field experiment was conducted to evaluate the response of Bombus terrestris colonies after the application of a tank mixture containing the insecticide chlorantraniliprole and the fungicide prochloraz, either in monofloral-managed lupin (Lupinus albus) as high pollen protein resource or in presence of an additional polyfloral flower mixture. Our results demonstrate an evident effect on worker mortality after application of the tank mixture. Higher worker mortality in polyfloral treatments compared to the untreated control was observed. The number of young brood and pupae in colonies in polyfloral control were significantly higher than in monofloral treatment. However, no long-term effects on the number or weight of new queens were found. Furthermore, flowering resources, but not pesticide exposure, affected colony weight. Exposure to the tank mixture resulted in declining nectar yeasts abundance and an increasing proportion of phylloplane yeasts in forager guts. In conclusion, diverse flowering resources are important for a bumble bee colony’s development. Even in a high pollen protein crop, low flower diversity may act as an additional stressor. Thus, we suggest further maintaining and promoting flowering strips or flowering fields in agricultural landscapes, even near high pollen protein crops, to enhance bee health.

Chimeric antigen receptor (CAR) T‐cell therapy represents a promising approach for cancer treatment, with receptor tyrosine kinase‐like orphan receptor 1 (ROR1) emerging as a novel target in malignancies. This study investigates how short‐chain fatty acids (SCFAs), key microbiota‐derived metabolites, modulate anti‐ROR1 CAR T‐cell efficacy using a physiologically relevant intestinal adenocarcinoma‐on‐chip model that replicates the human intestinal microenvironment. The findings demonstrate that propionate and butyrate inhibit anti‐ROR1 CAR T‐cell function by reducing infiltration, cytotoxicity, and cytokine release while preserving junctional integrity within the tumor model. Mechanistically, these SCFAs inhibit histone deacetylase activity and promote a phenotype switch toward regulatory T‐cells, as indicated by increased expression of FoxP3 and RORγt. Additionally, propionate and butyrate upregulate PD‐1 and TIM‐3, markers of T‐cell exhaustion and immune tolerance, and induce a dose‐ and time‐dependent reduction in proinflammatory cytokines. In contrast, acetate and pentanoate promote a proinflammatory T helper 17 phenotype. These results highlight the immunomodulatory effects of SCFAs on CAR T‐cell function, emphasizing the need to consider microbiota‐derived metabolites in CAR T‐cell therapies.

Inula viscosa (L.) Aiton [Dittrichia viscosa (L.) Greuter] (Asteraceae) is an evergreen perennial herb that grows in different regions of the Mediterranean Basin. It has been particularly used for the treatment of hypertension and diabetes in the Eastern and South-East regions of Morocco. To assess the cardiovascular effects of total aqueous extract and various fractions of Inula viscosa leaves in rat-isolated hearts and aortic rings, and to investigate the potential mechanisms of action of the most active extract(s). In Langendorff's isolated heart system, heart rate (HR) and left ventricular developed pressure (LVDP) were measured for three increasing concentrations of TAE, DCMF, EAF, BF, and AF (0.003, 0.03, and 0.3 mg/mL). Propranolol (1.5 × 10⁻⁵ M) and Verapamil (2 × 10⁻⁷ M) were used to investigate the potential mechanisms of action of both EAF and BF. In isolated intact aortic rings, four cumulative concentrations of EAF and BF (0.0001, 0.001, 0.01, and 1 mg/mL) were tested for their vasorelaxant effects. The role of the endothelium in the vasorelaxant effect of EAF was examined by denuding aortic rings. To explore the involvement of the nitric oxide (NO) pathway, β-adrenergic receptors, calcium channels, and the sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) pump, intact aortic rings were preincubated with L-NAME (10⁻⁴ M), Propranolol hydrochloride (10⁻⁶ M), Verapamil hydrochloride (10⁻⁵ M), and Thapsigargin (10⁻⁷ M), respectively. The hypotensive effects of both BF (125 mg/kg) and EAF (125 mg/kg) were evaluated indirectly using the tail-cuff method in normotensive rats. Additionally, the antioxidant activity, as well as the total phenolic and flavonoid contents of all prepared extracts, were determined. To further investigate the antioxidant properties, computational analysis was conducted to determine the bond dissociation energies of the hydroxyl groups on the B-ring of luteolin and quercetin, which are present in EAF and BF, respectively. Finally, an UHPLC analysis was performed for BF. In isolated perfused hearts, TAE induced a dose-dependent positive inotropic effect, accompanied by mild bradycardia. EAF exhibited both positive inotropic and chronotropic effects in a concentration-dependent manner. BF demonstrated a highly dose-dependent, selective positive inotropic effect (LVDP = 76.5 ± 19.2% vs. control at 0.3 mg/mL) with no significant impact on HR. Our findings suggest that BF acts independently of β-adrenoreceptor-dependent pathways, whereas EAF may exert its effects through β-agonistic activity. Additionally, Ca²⁺ channels may play a role in the effects of both fractions. In phenylephrine-precontracted thoracic arteries, both BF and EAF induced concentration-dependent vasorelaxation, with EAF producing the most potent vasorelaxant effect (Emax = 84.16 ± 3.68%). EAF mediates an endothelium-independent vasodilatory response through inhibition of voltage-dependent Ca²⁺ channels and activation of the SERCA pump. BF also demonstrated a significant hypotensive effect in vivo. Among the various extracts, BF contained the highest total phenolic and flavonoid contents and exhibited the strongest DPPH scavenging activity (IC50 = 7.13 µg/mL). Molecular docking studies supported these findings, indicating that quercetin is more effective at scavenging free radicals than luteolin. Phytochemical study of BF revealed the presence of phenolic compounds such as chlorogenic acid, three isochlorogenic acids (A, B and C), tri-caffeoylhexaric acid, methyl 3,5-dicaffeoylquinic acid, quercetin-3-glucuronide and the new molecule 1,3,4,5-tetracaffeoylaltraric acid. This study revealed a novel and potent selective inotropic effect of the BF fraction from I. viscosa leaves, characterized by the absence of tachycardia and independence from β-adrenergic receptors in isolated rat hearts.

In temperate climates, winter can be an arduous time for eusocial insects. Survival of honeybee colonies during winter depends on a delicate balance between hive thermoregulation, managing the food reserves and timing the onset of the new worker bee generation. Winter survival is influenced by several factors, most notably colony size, Varroa mite infestation levels and the availability of stored food. Importantly, the climatic conditions and floral resources of the previous foraging season can also impact honeybee health and colony strength before hibernation. This study, conducted across Europe, examines how landscape composition and weather conditions affect the winter survival of honeybee colonies. It uses pollen diversity as a proxy for flower resource quality and available foraging days as a climatic variable to understand their causal relationships to winter survival. We found that landscapes with higher percentages of agricultural areas increased pollen diversity collected by honeybees in autumn, whereas higher percentages of semi‐natural areas increased the diversity during summer. Spring and autumn pollen diversity was the main driver for winter survival success, emphasizing the importance of diverse flower resources for colony health. While we did not find a statistically significant effect of weather on winter survival, trends suggest potential influences, warranting further research to confirm and clarify the role of seasonal foraging on colony health. Synthesis and applications: Our study highlights the critical role of including floral resource diversity and weather conditions in a comprehensive framework for studying honeybee hibernation. It suggests that increasing plant diversity around apiaries and implementing agricultural practices that enhance floral resources can significantly improve winter survival, with honeybee colonies benefiting even in landscapes with higher agricultural activity, distinct from the needs of other pollinators.

Square-planar complexes were synthesized by the reaction of 2′,6′-di(thiazol-2-yl)-2,4′-bipyridine with either Na2[PdCl4] or K2[PtCl4], and these were thoroughly structurally characterized using some analytical and spectroscopic techniques. Density functional theory computations, including natural bond orbital analysis, were used to complement the experimental work to gain insight into the natural charge and electronic arrangement of the metal ion, as well as the strength of the metal–ligand bonds. The Pd(ii) complex exhibited exceptional cytotoxicity against the A549 and HCT-116 cell lines with IC50 values of 60.1 ± 3.45 and 23.8 ± 1.48 μM, respectively. Unfortunately, the Pd(ii) complex was harmful to the Vero normal cell line with an IC50 value of 24.5 ± 2.13 μM. The Pt(ii) complex is unstable and has a high likelihood of exchanging the chlorido ligand for solvent molecules such as DMSO. The fluorescent-stain photos of the treated HCT-116 cells with the Pd(ii) complex showed increased apoptotic bodies, indicating both early (18%) and late apoptosis (32%), as well as a necrosis ratio of about 10%. Flow cytometric analysis demonstrated that a cell arrest was induced by the Pd(ii) complex on HCT-116 cells in the G2/M phase.

Pseudofractures are atraumatic radiolucencies resulting from compromised bone mineralization and are often associated with poor clinical outcomes in patients with skeletal disorders. The incidence, clinical course of healing, and the risk of recurrence of pseudofractures are not well characterized, not least because pseudofractures and fractures are regularly reported under the general term “fractures,” despite underlying pathophysiological differences. Accordingly, this report is intended to conceptualize a grading scale for identifying and assessing pseudofractures. The scale was developed based on our clinical experience with. The proposed taxonomy includes 4 radiographically distinct stages, progressing from an unreactive initial Breach (Stage 1) to a stage with a visible Beak (Stage 2), appearance of a rounded Bump (Stage 3), and formation of a Bridge (Stage 4) across the interline. These scores correspond to radiographic transformations observed along the course of pseudofracture consolidation, although these stages of healing are reversible, and stagnation or relapse may occur at any stage. Dislocation should be indicated by adding a “d” to the score; adding an “s” indicates that the bone is clinically stable, meaning pain-free full weight-bearing is possible, because of surgical stabilization or sustainable cortical bridging (typically in Stage 4 or 0 [consolidation]). The scale may be used for any pseudofracture regardless of anatomical site or etiology. The proposed Breach–Beak–Bump–Bridge (4B) concept is a tool that can be used in clinical practice to assess pseudofractures over time and to improve specificity and clarity in communication of these findings.

Site‐specific modification of RNAs with functional handles enables studies of RNA structure, fate, function, and interactions. Ribozymes provide an elegant way to covalently modify an RNA of interest (ROI). Here, we report that the methyltransferase ribozyme MTR1 can be employed as a versatile tool for RNA modification and labeling. Using O6‐alkyl guanine cofactors, designed in analogy to SNAP‐tag substrates for protein labeling, MTR1 installs various bioorthogonal functional groups at N1 of a specific adenosine in the RNA target. In this application of ribozyme‐catalyzed RNA labeling, MTR1 is now called SNAPR. In contrast to the self‐labeling SNAP‐tag which is appended to the protein of interest, SNAPR is a truly intermolecular RNA catalyst. SNAPR assembles with the ROI to the active ribozyme, allowing for the transfer of clickable tags, such as azide and alkyne moieties, as well as photolabile groups or cross‐linkers from the guanine cofactor to the ROI. Moreover, we demonstrate a two‐step approach to attach labels at N6 of the target adenosine: first, SNAPR generates N1A‐modified RNA, followed by preparative Dimroth rearrangement to produce N6A‐modified RNA. We demonstrate this strategy with p‐azidobenzyl groups as photocrosslinker to generate covalent RNA‐protein conjugates. Overall, this work expands the toolbox for site‐specific RNA modification.

Object detection is one of the most common tasks in histopathological image analysis and generalization is a key requirement for the clinical applicability of deep object detection models. However, traditional evaluation metrics often fail to provide insights into why models fail on certain test cases, especially in the presence of domain shifts. In this work, we propose a novel quantitative method for assessing the discriminative power of a model’s latent space. Our approach, applicable to all object detection models with known local correspondences such as the popular RetinaNet, FCOS, or YOLO approaches, allows tracing discrimination across layers and coordinates. We motivate, adapt, and evaluate two suitable metrics, the generalized discrimination value and the Hellinger distance, and incorporate them into our approach. Through empirical validation on real-world histopathology datasets, we demonstrate the effectiveness of our method in capturing model discrimination properties and providing insights for architectural optimization. This work contributes to bridging the gap between model performance evaluation and understanding the underlying mechanisms influencing model behavior.

Site‐specific modification of RNAs with functional handles enables studies of RNA structure, fate, function, and interactions. Ribozymes provide an elegant way to covalently modify an RNA of interest (ROI). Here, we report that the methyltransferase ribozyme MTR1 can be employed as a versatile tool for RNA modification and labeling. Using O6‐alkyl guanine cofactors, designed in analogy to SNAP‐tag substrates for protein labeling, MTR1 installs various bioorthogonal functional groups at N1 of a specific adenosine in the RNA target. In this application of ribozyme‐catalyzed RNA labeling, MTR1 is now called SNAPR. In contrast to the self‐labeling SNAP‐tag which is appended to the protein of interest, SNAPR is a truly intermolecular RNA catalyst. SNAPR assembles with the ROI to the active ribozyme, allowing for the transfer of clickable tags, such as azide and alkyne moieties, as well as photolabile groups or cross‐linkers from the guanine cofactor to the ROI. Moreover, we demonstrate a two‐step approach to attach labels at N6 of the target adenosine: first, SNAPR generates N1A‐modified RNA, followed by preparative Dimroth rearrangement to produce N6A‐modified RNA. We demonstrate this strategy with p‐azidobenzyl groups as photocrosslinker to generate covalent RNA‐protein conjugates. Overall, this work expands the toolbox for site‐specific RNA modification.

Adaptive behavior in complex environments critically relies on the ability to appropriately link specific choices or actions to their outcomes. However, the neural mechanisms that support the ability to credit only those past choices believed to have caused the observed outcomes remain unclear. Here, we leverage multivariate pattern analyses of functional magnetic resonance imaging (fMRI) data and an adaptive learning task to shed light on the underlying neural mechanisms of such specific credit assignment. We find that the lateral orbitofrontal cortex (lOFC) and hippocampus (HC) code for the causal choice identity when credit needs to be assigned for choices that are separated from outcomes by a long delay, even when this delayed transition is punctuated by interim decisions. Further, we show when interim decisions must be made, learning is additionally supported by lateral frontopolar cortex (lFPC). Our results indicate that lFPC holds previous causal choices in a ‘pending’ state until a relevant outcome is observed, and the fidelity of these representations predicts the fidelity of subsequent causal choice representations in lOFC and HC during credit assignment. Together, these results highlight the importance of the timely reinstatement of specific causes in lOFC and HC in learning choice-outcome relationships when delays and choices intervene, a critical component of real-world learning and decision making.

Background Slope of the glomerular filtration rate (GFR) is considered a validated surrogate endpoint for chronic kidney disease (CKD) trials. However, differing short and long-term treatment effects on GFR slope can create ambiguities concerning the appropriate time period for evaluating slope, in part because current methods cannot separate the distinct contributions of the acute (before three months) and chronic (after three months) slopes for treatment effects on clinical endpoints. Methods We estimated treatment effects on the acute and chronic GFR slopes and on the established clinical endpoint (CE) of kidney failure or serum creatinine doubling for 66 randomized treatment comparisons from previous CKD clinical trials. We used a novel Bayesian meta-regression framework to relate treatment effects on the established CE to both the acute and chronic slopes in a single multivariable model to determine the independent contributions of the acute and chronic slopes. Results Treatment effects on both the acute and chronic slopes independently predicted the treatment effect on the established CE with a high median R ² (95% credible interval) of 0.95 (0.79,1.00). For a fixed treatment effect on the chronic slope, each 1 mL/min/1.73m ² greater acute GFR decline for the treatment vs. control increased the HR for the established CE by 11.4% (7.9%, 15.0%), against the treatment. The optimal weights for the acute and chronic slopes were consistent with the three-year total slope defined as the average slope extending from baseline to three years. Conclusion Treatment effects on both the acute and chronic GFR slopes are independent determinants of the effects on the established CE, with variation in acute effects accounting for much of the observed variation in treatment effects on the CE across previous trials. Our results establish that acute effects impact the CE independently of treatment effects on the chronic slope, and support the three-year total slope as the primary slope-based outcome in randomized trials.

The efficacy of conventional chemotherapy does not only rely on the cytotoxic action of the drug compound itself. Indeed, proper drug-induced immunogenic cell death (ICD) can stimulate immunosurveillance and mount a systemic anti-tumor response. We aimed to further amplify the therapeutic activity of oxaliplatin (OxPt) chemotherapy-induced ICD by combining this with an imidazoquinoline (IMDQ) TLR7/8 agonist. We hypothesized that innate immune activation by TLR7/8 activation primes the immune system against tumor neoantigens, thereby mounting tumor-specific T cell responses that contribute to killing primary tumor cells and distal metastases. To this end, we initially synthesized a covalent conjugate of OxPt, an imidazoquinoline TLR7/8 agonist (i.e., IMDQ), and an alkyl lipid. We hypothesized that such a lipidated conjugate would, upon intratumoral injection, increase the residence time in the tumor and reduce systemic dissemination and, hence, off-target toxicity. Whereas combination therapy with OxPt and IMDQ in native form improved, relative to single treatment, the anti-tumor efficacy against the primary treated tumor and a secondary distal tumor, this was not the case for OxPt–IMDQ-lipid conjugate therapy. We then altered the molecular design of the combination therapy and synthesized amphiphilic OxPt and IMDQ conjugates, comprising a cholesteryl motif and a hydrophilic poly(ethylene glycol) (PEG) chain. Intratumoral combination therapy with OxPt-PEG-cholesteryl and IMDQ-PEG-cholesteryl reduced, compared to native drug compounds, systemic innate inflammatory responses, and more efficiently eradicated primary and distal tumors. Furthermore, we found that combination therapy with OxPt-PEG-cholesteryl and IMDQ-PEG-cholesteryl induced antigen-specific anti-tumor responses and high infiltration levels of CD8+ T cells into the tumor.

Previous research suggests that older adults may display more prosocial behavior than younger adults. However, recent meta-analyses indicate that effects are heterogeneous, may be small, and are influenced by how prosociality is measured. Further, the precise cognitive and computational factors contributing to age-related differences in prosocial behavior remain largely unknown. In this study, we utilized a modified dictator game to combine a value-based decision framework with Bayesian hierarchical drift-diffusion modeling to investigate prosocial decision-making in a sample of younger (n = 63) and older adults (n = 48). We observed differences in how older and younger individuals incorporate information corresponding to potential gains for themselves (self) and another person (other) to reach a (potentially prosocial) decision. Younger adults integrated values for benefits for themselves and others in the decision-making process and demonstrated increased decision-making efficiency by effectively integrating both sources of information. In contrast, older adults showed improved decision-making efficiency when solely considering values for self and others separately. Interestingly, individual differences in the capacity of inhibitory control in older adults moderated the observed age effects: older adults with stronger inhibitory control abilities made decisions based on the integrated information of benefits for themselves and others. Together, these findings offer new insights into the behavioral and computational mechanisms influencing age effects in prosocial decision-making.

The first complexation of tungsten(VI) fluoride with N‐heterocyclic carbenes (NHCs) and a cyclic (alkyl)(amino) carbene (cAACMe) is reported, which led to the complexes [(NHC)WF6] (NHC = IiPrMe, 1; BIiPr, 2; IMes, 3; IDipp, 4; and SIDipp, 5) and [(cAACMe)WF₆] 6. Solid‐state structural analysis reveals distorted mono‐capped trigonal prismatic geometries for 2 and 3, whereas 6 adopts a pentagonal bipyramidal coordination. Reduction of 1–6 with 0.5 equivalents of TMS‐pyMe‐TMS afforded rare tungsten(V) fluoride complexes [(NHC)WF₅] (NHC = IiPrMe, 7; BIiPr, 8; IMes, 9; IDipp, 10 and SIDipp, 11). Reduction of 6 with TMS‐py‐TMS yielded the dinuclear, fluoride‐bridged complex [(cAACMe)WF₅]₂ 12. Subsequent addition of a second equivalent cAACMe to 12 gave the mononuclear bis‐carbene complex [(cAACMe)₂WF₅] 13. Magnetic susceptibility measurements and EPR spectroscopy confirm a predominantly metal‐centered d¹ radical in both 12 and 13. These findings expand the scope of tungsten fluoride chemistry by providing rare examples of tungsten(VI) and tungsten(V) complexes stabilized by soft carbon‐donor ligands, paving the way for further exploration.

The first complexation of tungsten(VI) fluoride with N‐heterocyclic carbenes (NHCs) and a cyclic (alkyl)(amino) carbene (cAACMe) is reported, which led to the complexes [(NHC)WF6] (NHC = IiPrMe, 1; BIiPr, 2; IMes, 3; IDipp, 4; and SIDipp, 5) and [(cAACMe)WF₆] 6. Solid‐state structural analysis reveals distorted mono‐capped trigonal prismatic geometries for 2 and 3, whereas 6 adopts a pentagonal bipyramidal coordination. Reduction of 1–6 with 0.5 equivalents of TMS‐pyMe‐TMS afforded rare tungsten(V) fluoride complexes [(NHC)WF₅] (NHC = IiPrMe, 7; BIiPr, 8; IMes, 9; IDipp, 10 and SIDipp, 11). Reduction of 6 with TMS‐py‐TMS yielded the dinuclear, fluoride‐bridged complex [(cAACMe)WF₅]₂ 12. Subsequent addition of a second equivalent cAACMe to 12 gave the mononuclear bis‐carbene complex [(cAACMe)₂WF₅] 13. Magnetic susceptibility measurements and EPR spectroscopy confirm a predominantly metal‐centered d¹ radical in both 12 and 13. These findings expand the scope of tungsten fluoride chemistry by providing rare examples of tungsten(VI) and tungsten(V) complexes stabilized by soft carbon‐donor ligands, paving the way for further exploration.