DREADDs are chemogenetic tools widely used to remotely control cellular signaling, neuronal activity, and behavior. Here we used a structure-based approach to develop a new Gi-coupled DREADD using ...the kappa-opioid receptor as a template (KORD) that is activated by the pharmacologically inert ligand salvinorin B (SALB). Activation of virally expressed KORD in several neuronal contexts robustly attenuated neuronal activity and modified behaviors. Additionally, co-expression of the KORD and the Gq-coupled M3-DREADD within the same neuronal population facilitated the sequential and bidirectional remote control of behavior. The availability of DREADDs activated by different ligands provides enhanced opportunities for investigating diverse physiological systems using multiplexed chemogenetic actuators.
•Structure-guided approach for κ-opioid receptor (KOR)-DREADD (KORD) design•KORD is selectively activated by salvinorin B, and not by endogenous opioids•KORD robustly silenced multiple neuronal subtypes•Inhibitory KORD combined with excitatory hM3Dq for multiplexed behavioral control
The κ-opioid receptor (KOR) was used as a template to generate a novel inhibitory DREADD (KORD), which is activated by salvinorin B and insensitive to endogenous opioid peptides. Sequential activation of the inhibitory KOR-DREADD and an excitatory M3-DREADD facilitated the bidirectional, multiplexed modulation of behavior.
G-protein-coupled receptors (GPCRs) remain major drug targets, despite our incomplete understanding of how they signal through 16 non-visual G-protein signal transducers (collectively named the ...transducerome) to exert their actions. To address this gap, we have developed an open-source suite of 14 optimized bioluminescence resonance energy transfer (BRET) Gαβγ biosensors (named TRUPATH) to interrogate the transducerome with single pathway resolution in cells. Generated through exhaustive protein engineering and empirical testing, the TRUPATH suite of Gαβγ biosensors includes the first Gα15 and GαGustducin probes. In head-to-head studies, TRUPATH biosensors outperformed first-generation sensors at multiple GPCRs and in different cell lines. Benchmarking studies with TRUPATH biosensors recapitulated previously documented signaling bias and revealed new coupling preferences for prototypic and understudied GPCRs with potential in vivo relevance. To enable a greater understanding of GPCR molecular pharmacology by the scientific community, we have made TRUPATH biosensors easily accessible as a kit through Addgene.
While desired for the cure of allergy, regulatory immune cell subsets and nonclassical Th2‐biased inflammatory mediators in the tumour microenvironment can contribute to immune suppression and escape ...of tumours from immunological detection and clearance. A key aim in the cancer field is therefore to design interventions that can break immunological tolerance and halt cancer progression, whereas on the contrary allergen immunotherapy exactly aims to induce tolerance. In this position paper, we review insights on immune tolerance derived from allergy and from cancer inflammation, focusing on what is known about the roles of key immune cells and mediators. We propose that research in the field of AllergoOncology that aims to delineate these immunological mechanisms with juxtaposed clinical consequences in allergy and cancer may point to novel avenues for therapeutic interventions that stand to benefit both disciplines.
Colorectal cancer (CRC) is one of the most common malignancies in Western countries. Over the last 20 years, and the last decade in particular, the clinical outcome for patients with metastatic CRC ...(mCRC) has improved greatly due not only to an increase in the number of patients being referred for and undergoing surgical resection of their localised metastatic disease but also to a more strategic approach to the delivery of systemic therapy and an expansion in the use of ablative techniques. This reflects the increase in the number of patients that are being managed within a multidisciplinary team environment and specialist cancer centres, and the emergence over the same time period not only of improved imaging techniques but also prognostic and predictive molecular markers. Treatment decisions for patients with mCRC must be evidence-based. Thus, these ESMO consensus guidelines have been developed based on the current available evidence to provide a series of evidence-based recommendations to assist in the treatment and management of patients with mCRC in this rapidly evolving treatment setting.
The shock-induced transition from graphite to diamond has been of great scientific and technological interest since the discovery of microscopic diamonds in remnants of explosively driven graphite. ...Furthermore, shock synthesis of diamond and lonsdaleite, a speculative hexagonal carbon polymorph with unique hardness, is expected to happen during violent meteor impacts. Here, we show unprecedented in situ X-ray diffraction measurements of diamond formation on nanosecond timescales by shock compression of pyrolytic as well as polycrystalline graphite to pressures from 19 GPa up to 228 GPa. While we observe the transition to diamond starting at 50 GPa for both pyrolytic and polycrystalline graphite, we also record the direct formation of lonsdaleite above 170 GPa for pyrolytic samples only. Our experiment provides new insights into the processes of the shock-induced transition from graphite to diamond and uniquely resolves the dynamics that explain the main natural occurrence of the lonsdaleite crystal structure being close to meteor impact sites.
We report the observation of a steepening in the cosmic ray energy spectrum of heavy primary particles at about 8×10(16) eV. This structure is also seen in the all-particle energy spectrum, but is ...less significant. Whereas the "knee" of the cosmic ray spectrum at 3-5×10(15) eV was assigned to light primary masses by the KASCADE experiment, the new structure found by the KASCADE-Grande experiment is caused by heavy primaries. The result is obtained by independent measurements of the charged particle and muon components of the secondary particles of extensive air showers in the primary energy range of 10(16) to 10(18) eV. The data are analyzed on a single-event basis taking into account also the correlation of the two observables.
Resistance towards the drug 5-fluorouracil (5-FU) is a key challenge in the adjuvant chemotherapy of colorectal cancer (CRC), and novel targeted approaches are required to improve the therapeutic ...outcome. Necroptosis is a recently discovered form of programmed cell death, which depends on receptor interacting protein 1 (RIP1) and particularly occurs under caspase-deficient conditions. The targeted induction of necroptosis represents a promising strategy to overcome apoptosis resistance in cancer. The aim of this study was to systematically explore the usage of pan-caspase inhibitors to sensitize resistant CRC cells for 5-FU. We found that pan-caspase inhibitors facilitated 5-FU-induced necroptosis, which was mediated by autocrine secretion of tumor necrosis factor α (TNF-α). TNF-α production was driven by nuclear factor κB (NF-κB) and required RIP1 kinase. In vivo xenograft experiments showed that the novel pan-caspase inhibitor IDN-7314 in combination with 5-FU synergistically blocked tumor growth. Ex vivo experiments with fresh human CRC tissue specimens further indicated that a subgroup of patients could benefit from combinatory treatment. Thereby, elevated levels of secreted TNF-α and expression of components of the necroptotic pathway might help to predict the sensitivity to pro-necroptotic therapies. Together, our results shed new light on the molecular regulation of necroptosis by NF-κB and RIP1. Moreover, we identify necroptotic cell death as an important effector mechanism of 5-FU-mediated anti-tumoral activity. On the basis of this study, we propose pan-caspase inhibitors as a novel approach in the adjuvant chemotherapy of CRC.
Elevated serum IgE levels are associated with allergic disorders, parasitosis and specific immunologic abnormalities. In addition, epidemiological and mechanistic evidence indicates an association ...between IgE‐mediated immune surveillance and protection from tumour growth. Intriguingly, recent studies reveal a correlation between IgE deficiency and increased malignancy risk. This is the first review discussing IgE levels and links to pathological conditions, with special focus on the potential clinical significance of ultra‐low serum IgE levels and risk of malignancy. In this Position Paper we discuss: (a) the utility of measuring total IgE levels in the management of allergies, parasitosis, and immunodeficiencies, (b) factors that may influence serum IgE levels, (c) IgE as a marker of different disorders, and d) the relationship between ultra‐low IgE levels and malignancy susceptibility. While elevated serum IgE is generally associated with allergic/atopic conditions, very low or absent IgE may hamper anti‐tumour surveillance, indicating the importance of a balanced IgE‐mediated immune function. Ultra‐low IgE may prove to be an unexpected biomarker for cancer risk. Nevertheless, given the early stage of investigations conducted mostly in patients with diseases that influence IgE levels, in‐depth mechanistic studies and stratification of malignancy risk based on associated demographic, immunological and clinical co‐factors are warranted.
Recent studies show that GPCRs rapidly interconvert between multiple states although our ability to interrogate, monitor and visualize them is limited by a relative lack of suitable tools. We ...previously reported two nanobodies (Nb39 and Nb6) that stabilize distinct ligand- and efficacy-delimited conformations of the kappa opioid receptor. Here, we demonstrate via X-ray crystallography a nanobody-targeted allosteric binding site by which Nb6 stabilizes a ligand-dependent inactive state. As Nb39 stabilizes an active-like state, we show how these two state-dependent nanobodies can provide real-time reporting of ligand stabilized states in cells in situ. Significantly, we demonstrate that chimeric GPCRs can be created with engineered nanobody binding sites to report ligand-stabilized states. Our results provide both insights regarding potential mechanisms for allosterically modulating KOR with nanobodies and a tool for reporting the real-time, in situ dynamic range of GPCR activity.
We present the results of the search for large-scale anisotropies in the arrival directions of cosmic rays performed with the KASCADE-Grande experiment at energies higher than eV. To eliminate ...spurious anisotropies due to atmospheric or instrumental effects we apply the east-west method. We show, using the solar time distribution of the number of counts, that this technique allow us to remove correctly the count variations not associated to real anisotropies. By applying the east-west method we obtain the distribution of number of counts in intervals of 20 minutes of sidereal time. This distribution is then analyzed by searching for a dipole component; the significance of the amplitude of the first harmonic is 3.5 , therefore, we derive its upper limit. The phase of the first harmonic is determined with an error of a few hours and is in agreement with the measurements obtained in the 1014 < E < 2 × 1015 eV energy range by the EAS-TOP, IceCube, and IceTop experiments. This supports the hypothesis of a change of the phase of the first harmonic at energies greater than ∼2 × 1014 eV.
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