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Background: Lung quantitative computed tomography (qCT) severe asthma clusters have been reported, but their replication and underlying disease mechanisms are unknown. We identified and replicated qCT clusters of severe asthma in two independent asthma cohorts and determined their association with molecular pathways, using radiomultiomics, integrating qCT, multiomics and machine learning/artificial intelligence., Methods: We used consensus clustering on qCT measurements of airway and lung CT scans, performed in 105 severe asthmatic adults from the U-BIOPRED cohort. The same qCT measurements were used to replicate qCT clusters in a subsample of the ATLANTIS asthma cohort (n=97). We performed integrated enrichment analysis using blood, sputum, bronchial biopsies, bronchial brushings and nasal brushings transcriptomics and blood and sputum proteomics to characterise radiomultiomic-associated clusters (RACs)., Results: qCT clusters and clinical features in U-BIOPRED were replicated in the matched ATLANTIS cohort. In the U-BIOPRED cohort, RAC1 (n=30) was predominantly female with elevated body mass index, mild airflow limitation, decreased CT lung volume and increased lung density and upregulation of the complement pathway. RAC2 (n=34) subjects had airway wall thickness and a mild degree of airflow limitation, with upregulation of proliferative pathways including neurotrophic receptor tyrosine kinase 2/tyrosine kinase receptor B, and downregulation of semaphorin pathways. RAC3 (n=41) showed increased lung attenuation area and air trapping, severe airflow limitation, hyperinflation, and upregulation of cytokine signalling and signalling by interleukin pathways, and matrix metallopeptidase 1, 2 and 9., Conclusions: U-BIOPRED severe asthma qCT clusters were replicated in a matched independent asthmatic cohort and associated with specific molecular pathways. Radiomultiomics might represent a novel strategy to identify new molecular pathways in asthma pathobiology., Competing Interests: Conflict of interest: K.F. Chung reports grants from the MRC, EPSRC, GSK, Merck and NIEHS, payment or honoraria for lectures, presentations, manuscript writing or educational events from GSK, Novartis and AstraZeneca, and participation on a data safety monitoring board or advisory board with GSK, AstraZeneca, Novartis, Roche, Merck, Trevi, Rickett-Beckinson, Nocion, Shionogi and Clean Breathing Institute supported by Haleon. C. Auffray reports support for the present study from the Innovative Medicines Initiative. Y. Badi reports support for the present study from the Innovative Medicines Initiative. P. Bakke reports payment or honoraria for lectures, presentations, manuscript writing or educational events from AstraZeneca, GSK and Sanofi. C. Brightling reports support for the present study from the ATLANTIS study (Chiesi grant) and Leicester NIHR BRC, grants from 4D Pharma, Areteia, AstraZeneca, Chiesi, Genentech, GSK, Mologic, Novartis, Regeneron Pharmaceuticals, Roche and Sanofi, and consultancy fees from 4D Pharma, Areteia, AstraZeneca, Chiesi, Genentech, GSK, Mologic, Novartis, Regeneron Pharmaceuticals, Roche and Sanofi. P. Chanez reports grants from ALK, AstraZeneca, Boehringer Ingelheim, Chiesi, GSK, Menarini, Novartis and Sanofi Aventis, consultancy fees from ALK, AstraZeneca, Boehringer Ingelheim, Chiesi, GSK, Menarini, Novartis and Sanofi Aventis, payment or honoraria for lectures, presentations, manuscript writing or educational events from ALK, AstraZeneca, Boehringer Ingelheim, Chiesi, GSK, Menarini, Novartis and Sanofi Aventis, and support for attending meetings from ALK, AstraZeneca, Boehringer Ingelheim, Chiesi, GSK, Menarini, Novartis and Sanofi Aventis. B. De Meulder reports support for the present study from the Innovative Medicines Initiative. R. Djukanovic reports consultancy fees from Synairgen plc, GSK, ZenasBio and Celltrion, leadership role as Chair of the European Respiratory Society's clinical research collaboration on severe asthma (SHARP), and stock (or stock options) with Synairgen plc. L. Fabbri reports consultancy fees from Chiesi Farmaceutici and AstraZeneca, payment or honoraria for lectures, presentations, manuscript writing or educational events from Chiesi Farmaceutici, AstraZeneca, GSK, Alfasigma and Novartis, support for attending meetings from Chiesi Farmaceutici, GSK and Novartis, and participation on a data safety monitoring board or advisory board with Novartis and Chiesi. S.J. Fowler reports grants from the NIHR, and payment or honoraria for lectures, presentations, manuscript writing or educational events from Boehringer Ingelheim. P. Howarth reports employment with GSK. J. Kolmert reports consultancy fees from Gesynta Pharma AB and Lipum AB. M. Kraft reports grants from the NIH, American Lung Association, Synairgen, Janssen, AstraZeneca and Sanofi, consultancy fees from AstraZeneca, Sanofi, Chiesi, GSK, Kinaset and Genentech, payment or honoraria for lectures, presentations, manuscript writing or educational events from Chiesi, support for attending meetings from the European Respiratory Society, one patent issued and tiled filed to development of therapeutics for inflammatory lung disease as CoFounder and Chief Medical Officer, RaeSedo, Inc., participation on a data safety monitoring board or advisory board with ALung, leadership role with the National Heart, Lung and Blood Advisory Council, stock (or stock options) with RaeSedo, Inc. (equity ownership), and the following financial (or non-financial) interests: Section Editor of UpToDate. A.H. Maitland-van der Zee reports grants from Health Holland, GSK, Boehringer Ingelheim and Vertex, consultancy fees from Boehringer Ingelheim and AstraZeneca, payment or honoraria for lectures, presentations, manuscript writing or educational events from GSK, and participation on a data safety monitoring board or advisory board for a study on BPD in neonates. A. Papi reports grants from Chiesi, AstraZeneca, GSK and Sanofi, consultancy fees from Chiesi, AstraZeneca, GSK, Novartis, Sanofi, Iqvia, Avillion, Elpen Pharmaceuticals, Moderna and Roche, payment or honoraria for lectures, presentations, manuscript writing or educational events from Chiesi, AstraZeneca, GSK, Menarini, Zambon, Mundipharma, Sanofi, Edmond Pharma, Iqvia, Avillion, Sanofi and Regeneron, participation on a data safety monitoring board or advisory board with Chiesi, AstraZeneca, GSK, Novartis, Sanofi, Iqvia, Avillion, Elpen Pharmaceuticals and Moderna, receipt of equipment, materials, drugs, medical writing, gifts or other services from Consorzio Futuro in Ricerca. K. Rabe reports payment or honoraria for lectures, presentations, manuscript writing or educational events from AstraZeneca, Boehringer Ingelheim, Chiesi Pharmaceuticals, Novartis, Sanofi/Regeneron, GSK, Berlin Chemie and Roche Pharma, participation on a data safety monitoring board or advisory board with AstraZeneca, Boehringer Ingelheim, Sanofi/Regeneron and CSL Behring, and leadership roles with the German Center for Lung Research (DZL), German Chest Society (DGP) and American Thoracic Society. D.E. Shaw reports consultancy fees from GSK, AstraZeneca and Novartis, payment or honoraria for lectures, presentations, manuscript writing or educational events from GSK and AstraZeneca, and support for attending meetings from GSK. D. Singh reports consultancy fees from Aerogen, AstraZeneca, Boehringer Ingelheim, Chiesi, Cipla, CSL Behring, EpiEndo, Genentech, GSK, Glenmark, Gossamer Bio, Kinaset Therapeutics, Menarini, Novartis, Orion, Pulmatrix, Sanofi, Synairgen, Teva, Theravance, Biopharma and Verona Pharma. M. van Den Berge reports grants from GSK, Roche, Genentech and Novartis. Y. Guo reports support for the present study from the Innovative Medicines Initiative. S. Wagers reports consultancy fees from King's College Hospital NHS Foundation Trust, Academic Medical Research, AMC Medical Research BV, Asthma UK, Athens Medical School, Boehringer Ingelheim International GmbH, CHU de Toulouse, CIRO, DS Biologicals Ltd, École Polytechnique Fédérale De Lausanne, European Respiratory Society, FISEVI, Fluidic Analytics Ltd, Fraunhofer IGB, Fraunhofer ITEM, GSK Research & Development Ltd, Holland & Knight, Karolinska Institutet Fakturor, KU Leuven, Longfonds, National Heart and Lung Institute, Novartis Pharma AG, Owlstone Medical Limited, PExA AB, UCB Biopharma SPRL, Umeå University, University Hospital Southampton NHS Foundation Trust, Università Campus Bio-Medico di Roma, Universita Cattolica Del Sacro Cuore, Universität Ulm, University of Bern, University of Edinburgh, University of Hull, University of Leicester, University of Loughborough, University of Luxembourg, University of Manchester, University of Nottingham, Vlaams Brabant, Dienst Europa, Imperial College London, Boehringer Ingelheim, Breathomix, Gossamer Bio, AstraZeneca, CIBER, OncoRadiomics, University of Leiden, University of Wurzburg, Chiesi Pharmaceutical, University of Liege, Teva Pharmaceuticals, Sanofi, Pulmonary Fibrosis Foundation and Three Lakes Foundation. P.J. Sterk reports consultancy fees from SME Breathomix, and stock (or stock options) with SME Breathomix. S-E. Dahlen reports grants from AstraZeneca, GSK and Sanofi, consultancy fees from AstraZeneca, Cayman Chemicals, GSK and Regeneron, and payment or honoraria for lectures, presentations, manuscript writing or educational events from AstraZeneca, GSK and Sanofi. I.M. Adcock reports support for the present study from the Innovative Medicines Initiative, grants from GSK, MRC, EPSRC and Sanofi, consultancy fees from GSK, Sanofi, Chiesi and Kinaset, payment or honoraria for lectures, presentations, manuscript writing or educational events from AstraZeneca, Sanofi, Eurodrug and Sunovion, and support for attending meetings from AstraZeneca. S. Siddiqui consultancy fees from AstraZeneca, GSK, CSL Behring, Areteia Therapeutics, ERT Medical, Chiesi and Roche, and payment or honoraria for lectures, presentations, manuscript writing or educational events from GSK, Chiesi and AstraZeneca. P. Montuschi reports support for the present study from the Innovative Medicines Initiative. The remaining authors have no potential conflicts of interest to disclose., (Copyright ©The authors 2024.)

Purpose: Asthma is a clinical syndrome with various underlying pathomechanisms and clinical phenotypes. Genetic, ethnic, and geographic factors may influence the differences in clinical presentation, severity, and prognosis. We compared the characteristics of asthma based on the geographical background by analyzing representative cohorts from the United States, Europe, South America, and Asia using the Severe Asthma Research Program (SARP), Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED), Program for Control of Asthma in Bahia (ProAR), and Cohort for Reality and Evolution of Adult Asthma in Korea (COREA), respectively., Methods: The clinical characteristics and medications for the SARP (n = 669), U-BIOPRED (n = 509), ProAR (n = 996), and COREA (n = 3,748) were analyzed. Subgroup analysis was performed for severe asthma., Results: The mean age was highest and lowest in the COREA and SARP, respectively. The asthma onset age was lowest in the ProAR. The mean body mass index was highest and lowest in the SARP and COREA, respectively. Baseline pulmonary function was lowest and highest in the U-BIOPRED and COREA, respectively. The number of patients with acute exacerbation in the previous year was highest in U-BIOPRED. The mean blood eosinophil count was highest in COREA. The total immunoglobulin E was highest in the ProAR. The frequency of atopy was highest in the SARP. The principal component analysis plot revealed differences among all cohorts., Conclusions: The cohorts from 4 different continents exhibited different clinical and physiological characteristics, probably resulting from the interplay between genetic susceptibility and geographical factors., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2024 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Background: Rare cystic lung diseases are increasingly recognised due the wider application of CT scanning making cystic lung disease management a growing part of respiratory care. Cystic lung diseases tend to have extrapulmonary features that can both be diagnostic but also require surveillance and treatment in their own right. As some of these diseases now have specific treatments, making a precise diagnosis is crucial. While Langerhans cell histiocytosis, Birt-Hogg-Dubé syndrome, lymphoid interstitial pneumonia and lymphangioleiomyomatosis are becoming relatively well-known diseases to respiratory physicians, a targeted and thorough workup improves diagnostic accuracy and may suggest other ultrarare diseases such as light chain deposition disease, cystic pulmonary amyloidosis, low-grade metastatic neoplasms or infections. In many cases, diagnostic information is overlooked leaving uncertainty over the disease course and treatments., Aims: This position statement from the Rare Disease Collaborative Network for cystic lung diseases will review how clinical, radiological and physiological features can be used to differentiate between these diseases., Narrative: We highlight that in many cases a multidisciplinary diagnosis can be made without the need for lung biopsy and discuss where tissue sampling is necessary when non-invasive methods leave diagnostic doubt. We suggest an initial workup focusing on points in the history which identify key disease features, underlying systemic and familial diseases and a clinical examination to search for connective tissue disease and features of genetic causes of lung cysts. All patients should have a CT of the thorax and abdomen to characterise the pattern and burden of lung cysts and extrapulmonary features and also spirometry, gas transfer and a 6 min walk test. Discussion with a rare cystic lung disease centre is suggested before a surgical biopsy is undertaken., Conclusions: We suggest that this focused workup should be performed in all people with multiple lung cysts and would streamline referral pathways, help guide early treatment, management decisions, improve patient experience and reduce overall care costs. It could also potentially catalyse a national research database to describe these less well-understood and unidentified diseases, categorise disease phenotypes and outcomes, potentially leading to better prognostic data and generating a stronger platform to understand specific disease biology., Competing Interests: Competing interests: AGN reports fees from Galapagos, Medical Quantitative Image Analysis, Roche, Boehringer Ingelheim in relation to interstitial lung disease and lecture fees from Boehringer Ingelheim, UpToDate. PMG reports grants and consulting fees from Boehringer Ingelheim; speaker fees from Boehringer Ingelheim, Roche Pharmaceuticals, AstraZeneca and Cipla; meeting support from Boehringer Ingelheim and Roche Pharmaceuticals; and stock options in Brainomix. SRJ reports grants from the Medical Research Council, NIHR, LAM Action and the LAM Foundation, and educational fees from Boehringer Ingelheim. SRD reports educational fees from Boehringer Ingelheim and advisory fees from GlaxoSmithKline and AstraZeneca., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

PIK3CA (PI3Kα) is a lipid kinase commonly mutated in cancer, including ∼40% of hormone receptor-positive breast cancer. The most frequently observed mutants occur in the kinase and helical domains. Orthosteric PI3Kα inhibitors suffer from poor selectivity leading to undesirable side effects, most prominently hyperglycemia due to inhibition of wild-type (WT) PI3Kα. Here, we used molecular dynamics simulations and cryo-electron microscopy to identify an allosteric network that provides an explanation for how mutations favor PI3Kα activation. A DNA-encoded library screen leveraging electron microscopy-optimized constructs, differential enrichment, and an orthosteric-blocking compound led to the identification of RLY-2608, a first-in-class allosteric mutant-selective inhibitor of PI3Kα. RLY-2608 inhibited tumor growth in PIK3CA-mutant xenograft models with minimal impact on insulin, a marker of dysregulated glucose homeostasis. RLY-2608 elicited objective tumor responses in two patients diagnosed with advanced hormone receptor-positive breast cancer with kinase or helical domain PIK3CA mutations, with no observed WT PI3Kα-related toxicities., Significance: Treatments for PIK3CA-mutant cancers are limited by toxicities associated with the inhibition of WT PI3Kα. Molecular dynamics, cryo-electron microscopy, and DNA-encoded libraries were used to develop RLY-2608, a first-in-class inhibitor that demonstrates mutant selectivity in patients. This marks the advance of clinical mutant-selective inhibition that overcomes limitations of orthosteric PI3Kα inhibitors. See related commentary by Gong and Vanhaesebroeck, p. 204 . See related article by Varkaris et al., p. 227 . This article is featured in Selected Articles from This Issue, p. 201., (©2023 The Authors; Published by the American Association for Cancer Research.)

Fibroblast growth factor receptor (FGFR) kinase inhibitors have been shown to be effective in the treatment of intrahepatic cholangiocarcinoma and other advanced solid tumors harboring FGFR2 alterations, but the toxicity of these drugs frequently leads to dose reduction or interruption of treatment such that maximum efficacy cannot be achieved. The most common adverse effects are hyperphosphatemia caused by FGFR1 inhibition and diarrhea due to FGFR4 inhibition, as current therapies are not selective among the FGFRs. Designing selective inhibitors has proved difficult with conventional approaches because the orthosteric sites of FGFR family members are observed to be highly similar in X-ray structures. In this study, aided by analysis of protein dynamics, we designed a selective, covalent FGFR2 inhibitor. In a key initial step, analysis of long-timescale molecular dynamics simulations of the FGFR1 and FGFR2 kinase domains allowed us to identify differential motion in their P-loops, which are located adjacent to the orthosteric site. Using this insight, we were able to design orthosteric binders that selectively and covalently engage the P-loop of FGFR2. Our drug discovery efforts culminated in the development of lirafugratinib (RLY-4008), a covalent inhibitor of FGFR2 that shows substantial selectivity over FGFR1 (~250-fold) and FGFR4 (~5,000-fold) in vitro, causes tumor regression in multiple FGFR2 -altered human xenograft models, and was recently demonstrated to be efficacious in the clinic at doses that do not induce clinically significant hyperphosphatemia or diarrhea., Competing Interests: Competing interests statement:Some authors are currently or have in the past been Relay employees. Some authors may own Relay stock. Relay (and some of the authors) have pending patents containing claims for lirafugratinib: World Intellectual Property Organization, WO2022109577 A1 2022-05-27; World Intellectual Property Organization, WO2020231990 A1 2020-11-19; US 11780845 B2 2023-10-10.

Allele-specific gene expression evolves rapidly on heteromorphic sex chromosomes. Over time, the accumulation of mutations on the Y chromosome leads to widespread loss of gametolog expression, relative to the X chromosome. It remains unclear if expression evolution on degrading Y chromosomes is primarily driven by mutations that accumulate through processes of selective interference, or if positive selection can also favor the down-regulation of coding regions on the Y chromosome that contain deleterious mutations. Identifying the relative rates of cis-regulatory sequence evolution across Y chromosomes has been challenging due to the limited number of reference assemblies. The threespine stickleback (Gasterosteus aculeatus) Y chromosome is an excellent model to identify how regulatory mutations accumulate on Y chromosomes due to its intermediate state of divergence from the X chromosome. A large number of Y-linked gametologs still exist across 3 differently aged evolutionary strata to test these hypotheses. We found that putative enhancer regions on the Y chromosome exhibited elevated substitution rates and decreased polymorphism when compared to nonfunctional sites, like intergenic regions and synonymous sites. This suggests that many cis-regulatory regions are under positive selection on the Y chromosome. This divergence was correlated with X-biased gametolog expression, indicating the loss of expression from the Y chromosome may be favored by selection. Our findings provide evidence that Y-linked cis-regulatory regions exhibit signs of positive selection quickly after the suppression of recombination and allow comparisons with recent theoretical models that suggest the rapid divergence of regulatory regions may be favored to mask deleterious mutations on the Y chromosome., Competing Interests: Conflict of Interest The authors declare no conflicts of interests., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)

Asthma has been recognised as a respiratory disorder for millennia and the focus of targeted drug development for the last 120 years. Asthma is one of the most common chronic non-communicable diseases worldwide. Chronic obstructive pulmonary disease (COPD), a leading cause of morbidity and mortality worldwide, is caused by exposure to tobacco smoke and other noxious particles and exerts a substantial economic and social burden. This chapter reviews the development of the treatments of asthma and COPD particularly focussing on the β-agonists, from the isolation of adrenaline, through the development of generations of short- and long-acting β-agonists. It reviews asthma death epidemics, considers the intrinsic efficacy of clinical compounds, and charts the improvement in selectivity and duration of action that has led to our current medications. Important β2-agonist compounds no longer used are considered, including some with additional properties, and how the different pharmacological properties of current β2-agonists underpin their different places in treatment guidelines. Finally, it concludes with a look forward to future developments that could improve the β-agonists still further, including extending their availability to areas of the world with less readily accessible healthcare., (© 2023. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

The cation channel TRPA1 is a potentially important drug target, and characterization of TRPA1 functional dynamics might help guide structure-based drug design. Here, we present results from long-timescale molecular dynamics simulations of TRPA1 with an allosteric activator, allyl isothiocyanate (AITC), in which we observed spontaneous transitions from a closed, non-conducting channel conformation into an open, conducting conformation. Based on these transitions, we propose a gating mechanism in which movement of a regulatory TRP-like domain allosterically translates into pore opening in a manner reminiscent of pore opening in voltage-gated ion channels. In subsequent experiments, we found that mutations that disrupt packing of the S4-S5 linker-TRP-like domain and the S5 and S6 helices also affected channel activity. In simulations, we also observed A-967079, a known allosteric inhibitor, binding between helices S5 and S6, suggesting that A-967079 may suppress activity by stabilizing a non-conducting pore conformation-a finding consistent with our proposed gating mechanism., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Protein tyrosine phosphatase SHP2 mediates RAS-driven MAPK signaling and has emerged in recent years as a target of interest in oncology, both for treating with a single agent and in combination with a KRAS inhibitor. We were drawn to the pharmacological potential of SHP2 inhibition, especially following the initial observation that drug-like compounds could bind an allosteric site and enforce a closed, inactive state of the enzyme. Here, we describe the identification and characterization of GDC-1971 (formerly RLY-1971), a SHP2 inhibitor currently in clinical trials in combination with KRAS G12C inhibitor divarasib (GDC-6036) for the treatment of solid tumors driven by a KRAS G12C mutation.

Rationale: Patients with severe asthma are dependent upon treatment with high doses of inhaled corticosteroids (ICS) and often also oral corticosteroids (OCS). The extent of endogenous androgenic anabolic steroid (EAAS) suppression in asthma has not previously been described in detail. The objective of the present study was to measure urinary concentrations of EAAS in relation to exogenous corticosteroid exposure., Methods: Urine collected at baseline in the U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Disease outcomes) study of severe adult asthmatics (SA, n=408) was analysed by quantitative mass spectrometry. Data were compared to that of mild-to-moderate asthmatics (MMA, n=70) and healthy subjects (HC, n=98) from the same study., Measurements and Main Results: The concentrations of urinary endogenous steroid metabolites were substantially lower in SA than in MMA or HC. These differences were more pronounced in SA patients with detectable urinary OCS metabolites. Their dehydroepiandrosterone sulfate (DHEA-S) concentrations were <5% of those in HC, and cortisol concentrations were below the detection limit in 75% of females and 82% of males. The concentrations of EAAS in OCS-positive patients, as well as patients on high-dose ICS only, were more suppressed in females than males (p<0.05). Low levels of DHEA were associated with features of more severe disease and were more prevalent in females (p<0.05). The association between low EAAS and corticosteroid treatment was replicated in 289 of the SA patients at follow-up after 12-18 months., Conclusion: The pronounced suppression of endogenous anabolic androgens in females might contribute to sex differences regarding the prevalence of severe asthma., Competing Interests: Conflict of interest: V. Yasinska reports participation in advisory boards for AZ and GSK, and lecture honoraria from Sanofi and GSK. Conflict of interest: C. Gómez has nothing to disclose. Conflict of interest: J. Kolmert has nothing to disclose. Conflict of interest: M. Ericsson has nothing to disclose. Conflict of interest: A. Pohanka has nothing to disclose. Conflict of interest: A. James reports personal grant from Swedish Heart-Lung Foundation. Conflict of interest: L.I. Andersson has nothing to disclose. Conflict of interest: M. Sparreman-Mikus has nothing to disclose. Conflict of interest: A.R. Sousa reports employment and stocks or stock options from GSK. Conflict of interest: J.H. Riley has nothing to disclose. Conflict of interest: S. Bates has nothing to disclose. Conflict of interest: P.S. Bakke reports lecture honoraria from AstraZeneca and Boehringer Ingelheim. Conflict of interest: N. Zounemat Kermani has nothing to disclose. Conflict of interest: M. Caruso has nothing to disclose. Conflict of interest: P. Chanez reports participation in advisory boards, honoraria for consultancy, lectures fees and support for attending and/or travel from ALK, Almirall, AZ, Chiesi, GSK, Menarini, Novartis and Sanofi. Conflict of interest: S.J. Fowler has nothing to disclose. Conflict of interest: T. Geiser has nothing to disclose. Conflict of interest: P.H. Howarth reports employment and stocks or stock options from GSK. Conflict of interest: I. Horváth reports participation on an advisory board for AZ and Chiesi, honoraria for lectures from Chiesi and Roche, and support for attending and/or travel from Roche. Conflict of interest: N. Krug has nothing to disclose. Conflict of interest: P. Montuschi has nothing to disclose. Conflict of interest: M. Sanak has nothing to disclose. Conflict of interest: A. Behndig has nothing to disclose. Conflict of interest: D.E. Shaw has nothing to disclose. Conflict of interest: R.G. Knowles has nothing to disclose. Conflict of interest: B. Dahlén reports grant from GSK and Novartis. Conflict of interest: A-H. Maitland-van der Zee reports grants from BI, Vertex Innovation Award, Dutch Lung Foundation, Stichting Astma Bestrijding, IMI/3TR, EU grant ONELAB and EUROSTARS grant with Respiq, consulting fees from AZ and BI, and lecture honoraria from GSK. Conflict of interest: P.J. Sterk reports a grant from the Innovative Medicines Initiative. Conflict of interest: R. Djukanovic reports consulting fees from Synairgen, lecture honoraria from Regeneron, GSK and Kymab, and an advisory board for Synairgen. Conflict of interest: I.M. Adcock reports grant from EU-IMI, grants from GSK, MRK, EPSRC and Sanofi, consulting fees from GSK, Sanofi, Chiesi and Kinaset, lecture honoraria from AZ, Sanofi and Eurodrug, and payment for an educational event from Sunovion. Conflict of interest: K.F. Chung reports lectures honoraria from Novartis, AZ and Merck, advisory boards for GSK, AZ, Novartis, Roche, Merck, Rickett-Beckinson, Nocion and Shionogi, the Scientific Advisory Board of the Clean Breathing Institute supported by Haleon, grants from GSK, MRC and EPSRC, and support for travel from AZ. Conflict of interest: C.E. Wheelock has nothing to disclose. Conflict of interest: S-E. Dahlén reports research grants, consulting fees or lecture honoraria from AZ, Cayman Chemicals, GSK, Regeneron, Sanofi and Teva. Conflict of interest: E. Wikström Jonsson reports a research grant and expert assignment by Region Stockholm, and an expert appointment by the Swedish Medical Product Agency., (Copyright ©The authors 2023.)

Oncogenic activation of fibroblast growth factor receptor 2 (FGFR2) drives multiple cancers and represents a broad therapeutic opportunity, yet selective targeting of FGFR2 has not been achieved. Although the clinical efficacy of pan-FGFR inhibitors (pan-FGFRi) validates FGFR2 driver status in FGFR2 fusion-positive intrahepatic cholangiocarcinoma, their benefit is limited by incomplete target coverage due to FGFR1- and FGFR4-mediated toxicities (hyperphosphatemia and diarrhea, respectively) and the emergence of FGFR2 resistance mutations. RLY-4008 is a highly selective, irreversible FGFR2 inhibitor designed to overcome these limitations. In vitro, RLY-4008 demonstrates >250- and >5,000-fold selectivity over FGFR1 and FGFR4, respectively, and targets primary alterations and resistance mutations. In vivo, RLY-4008 induces regression in multiple xenograft models-including models with FGFR2 resistance mutations that drive clinical progression on current pan-FGFRi-while sparing FGFR1 and FGFR4. In early clinical testing, RLY-4008 induced responses without clinically significant off-isoform FGFR toxicities, confirming the broad therapeutic potential of selective FGFR2 targeting., Significance: Patients with FGFR2-driven cancers derive limited benefit from pan-FGFRi due to multiple FGFR1-4-mediated toxicities and acquired FGFR2 resistance mutations. RLY-4008 is a highly selective FGFR2 inhibitor that targets primary alterations and resistance mutations and induces tumor regression while sparing other FGFRs, suggesting it may have broad therapeutic potential. See related commentary by Tripathi et al., p. 1964. This article is featured in Selected Articles from This Issue, p. 1949., (©2023 The Authors; Published by the American Association for Cancer Research.)

Rationale: Children with preschool wheezing or school-age asthma are reported to have airway microbial imbalances. Objectives: To identify clusters in children with asthma or wheezing using oropharyngeal microbiota profiles. Methods: Oropharyngeal swabs from the U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes) pediatric asthma or wheezing cohort were characterized using 16S ribosomal RNA gene sequencing, and unsupervised hierarchical clustering was performed on the Bray-Curtis β-diversity. Enrichment scores of the Molecular Signatures Database hallmark gene sets were computed from the blood transcriptome using gene set variation analysis. Children with severe asthma or severe wheezing were followed up for 12-18 months, with assessment of the frequency of exacerbations. Measurements and Main Results: Oropharyngeal samples from 241 children (age range, 1-17 years; 40% female) revealed four taxa-driven clusters dominated by Streptococcus , Veillonella , Rothia , and Haemophilus . The clusters showed significant differences in atopic dermatitis, grass pollen sensitization, FEV 1 % predicted after salbutamol, and annual asthma exacerbation frequency during follow-up. The Veillonella cluster was the most allergic and included the highest percentage of children with two or more exacerbations per year during follow-up. The oropharyngeal clusters were different in the enrichment scores of TGF-β (transforming growth factor-β) (highest in the Veillonella cluster) and Wnt/β-catenin signaling (highest in the Haemophilus cluster) transcriptomic pathways in blood (all q values <0.05). Conclusions: Analysis of the oropharyngeal microbiota of children with asthma or wheezing identified four clusters with distinct clinical characteristics (phenotypes) that associate with risk for exacerbation and transcriptomic pathways involved in airway remodeling. This suggests that further exploration of the oropharyngeal microbiota may lead to novel pathophysiologic insights and potentially new treatment approaches.

Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of the insulin and leptin signaling pathways, making it a highly attractive target for the treatment of type II diabetes. For PTP1B to perform its enzymatic function, a loop referred to as the "WPD loop" must transition between open (catalytically incompetent) and closed (catalytically competent) conformations, which have both been resolved by X-ray crystallography. Although prior studies have established this transition as the rate-limiting step for catalysis, the transition mechanism for PTP1B and other PTPs has been unclear. Here we present an atomically detailed model of WPD loop transitions in PTP1B based on unbiased, long-timescale molecular dynamics simulations and weighted ensemble simulations. We found that a specific WPD loop region─the PDFG motif─acted as the key conformational switch, with structural changes to the motif being necessary and sufficient for transitions between long-lived open and closed states of the loop. Simulations starting from the closed state repeatedly visited open states of the loop that quickly closed again unless the infrequent conformational switching of the motif stabilized the open state. The functional importance of the PDFG motif is supported by the fact that it is well conserved across PTPs. Bioinformatic analysis shows that the PDFG motif is also conserved, and adopts two distinct conformations, in deiminases, and the related DFG motif is known to function as a conformational switch in many kinases, suggesting that PDFG-like motifs may control transitions between structurally distinct, long-lived conformational states in multiple protein families.

Background: Asthma is a chronic respiratory disease with significant heterogeneity in its clinical presentation and pathobiology. There is need for improved understanding of respiratory lipid metabolism in asthma patients and its relation to observable clinical features., Objective: We performed a comprehensive, prospective, cross-sectional analysis of the lipid composition of induced sputum supernatant obtained from asthma patients with a range of disease severities, as well as from healthy controls., Methods: Induced sputum supernatant was collected from 211 adults with asthma and 41 healthy individuals enrolled onto the U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes) study. Sputum lipidomes were characterized by semiquantitative shotgun mass spectrometry and clustered using topologic data analysis to identify lipid phenotypes., Results: Shotgun lipidomics of induced sputum supernatant revealed a spectrum of 9 molecular phenotypes, highlighting not just significant differences between the sputum lipidomes of asthma patients and healthy controls, but also within the asthma patient population. Matching clinical, pathobiologic, proteomic, and transcriptomic data helped inform the underlying disease processes. Sputum lipid phenotypes with higher levels of nonendogenous, cell-derived lipids were associated with significantly worse asthma severity, worse lung function, and elevated granulocyte counts., Conclusion: We propose a novel mechanism of increased lipid loading in the epithelial lining fluid of asthma patients resulting from the secretion of extracellular vesicles by granulocytic inflammatory cells, which could reduce the ability of pulmonary surfactant to lower surface tension in asthmatic small airways, as well as compromise its role as an immune regulator., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Growing evidence indicates high comorbid anxiety and depression in patients with asthma. However, the mechanisms underlying this comorbid condition remain unclear. The aim of this study was to investigate the role of inflammation in comorbid anxiety and depression in three asthma patient cohorts of the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) project., Methods: U-BIOPRED was conducted by a European Union consortium of 16 academic institutions in 11 European countries. A subset dataset from subjects with valid anxiety and depression measures and a large blood biomarker dataset were analysed, including 198 non-smoking patients with severe asthma (SAn), 65 smoking patients with severe asthma (SAs), 61 non-smoking patients with mild-to-moderate asthma (MMA), and 20 healthy non-smokers (HC). The Hospital Anxiety and Depression Scale was used to measure anxiety and depression and a series of inflammatory markers were analysed by the SomaScan v3 platform (SomaLogic, Boulder, Colo). ANOVA and the Kruskal-Wallis test were used for multiple-group comparisons as appropriate., Results: There were significant group effects on anxiety and depression among the four cohort groups (p < 0.05). Anxiety and depression of SAn and SAs groups were significantly higher than that of MMA and HC groups (p < 0.05. There were significant differences in serum IL6, MCP1, CCL18, CCL17, IL8, and Eotaxin among the four groups (p < 0.05). Depression was significantly associated with IL6, MCP1, CCL18 level, and CCL17; whereas anxiety was associated with CCL17 only (p < 0.05)., Conclusions: The current study suggests that severe asthma patients are associated with higher levels of anxiety and depression, and inflammatory responses may underlie this comorbid condition., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Professor Hou sits on the ECNP Scientific Advisory Panel and currently holds a grant from Asthma Allergy Inflammation Research charity. Prof. Shaw receives consulting fees from Adherium, Nuvoair, Astra Zeneca and Chiesi. He also receives honoraria from Astra Zeneca and Chiesi and travel support from Chiesi and GSK. Professor Sven-Eric Dahlén declares consulting fees from Astra Zenica, Cayman Chemicals, GSK, Novartis, Regeneron, Sanofi and Teva and honorarium from Sanofi. Dr Barbro Dahlén is in receipt of grants from GSK and Novartis and declares consulting fees from Novartis, Astra Zeneca and Sanofi. She is on the advisory board for Astra Zeneca and Sanofi. Prof. Fowler receives a grant from Boehringer Ingelheim and an honorarium from Chiesi. Prof. Sandstrom received payment for the Boehringer Ingelheim lecture (paid to his institution). Dr Auffrey and Dr De Meulder have both received support for the manuscript from the Innovative Medicines Initiative. Prof. Adcock has received grants from GSK, MRC and EPSRC. He also declares consulting fees from GSK, Sanofi, Chiesi and Kinaset. He has received honoraria from Astra Zeneca, Sanofi, Eurodrug, and Sunovion. He has also received payment for expert testimony from Chiesi and travel support from Astra Zeneca. Prof. Chung is in receipt of grants from MRC, EPSRC and GSK and honoraria from Astra Zeneca and Novartis. He is on the advisory board of Astra Zeneca, GSK, Roche and Novartis. Prof. Sterk received a grant from Innovative Medicines Initiative and has a non-substantial interest in SME Breathomix. Prof. Skipp has a grant from EU UBIOPRED IMI FP and is a shareholder in TopMD Precision Medicine Ltd. Prof. Djukanovic receives consulting fees from Synairgen and honoraria from Regeneron, GSK and is on the advisory board for Synairgen. He also holds stock in Synairgen. Dr Ye, Dr Cheng, Dr Bakke, Dr Caruso, Dr Horvárth, Prof. Howarth, Dr Krug, Dr Montuschi, Dr Sanak and Dr Schofield report no potential conflict of interest., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Pulmonary arterial hypertension (PAH) is a devastating rare disease, which despite currently available treatments, still represents a high unmet medical need. Specific E3 ubiquitin protein ligase 1 (SMURF1) is a HECT E3 ligase that ubiquitinates key signaling molecules from the TGFβ/BMP pathways, which are of great relevance in the pathophysiology of PAH. Herein, the design and synthesis of novel potent small-molecule SMURF1 ligase inhibitors are described. Lead molecule 38 has demonstrated good oral pharmacokinetics in rats and significant efficacy in a rodent model of pulmonary hypertension.

To perform their physiological functions, amino methyl propionic acid receptors (AMPARs) cycle through active, resting, and desensitized states, and dysfunction in AMPAR activity is associated with various neurological disorders. Transitions among AMPAR functional states, however, are largely uncharacterized at atomic resolution and are difficult to examine experimentally. Here, we report long-timescale molecular dynamics simulations of dimerized AMPAR ligand-binding domains (LBDs), whose conformational changes are tightly coupled to changes in AMPAR functional states, in which we observed LBD dimer activation and deactivation upon ligand binding and unbinding at atomic resolution. Importantly, we observed the ligand-bound LBD dimer transition from the active conformation to several other conformations, which may correspond with distinct desensitized conformations. We also identified a linker region whose structural rearrangements heavily affected the transitions to and among these putative desensitized conformations, and confirmed, using electrophysiology experiments, the importance of the linker region in these functional transitions., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Proteins often undergo large conformational changes when binding small molecules, but atomic-level descriptions of such events have been elusive. Here, we report unguided molecular dynamics simulations of Abl kinase binding to the cancer drug imatinib. In the simulations, imatinib first selectively engages Abl kinase in its autoinhibitory conformation. Consistent with inferences drawn from previous experimental studies, imatinib then induces a large conformational change of the protein to reach a bound complex that closely resembles published crystal structures. Moreover, the simulations reveal a surprising local structural instability in the C-terminal lobe of Abl kinase during binding. The unstable region includes a number of residues that, when mutated, confer imatinib resistance by an unknown mechanism. Based on the simulations, NMR spectra, hydrogen-deuterium exchange measurements, and thermostability measurements and estimates, we suggest that these mutations confer imatinib resistance by exacerbating structural instability in the C-terminal lobe, rendering the imatinib-bound state energetically unfavorable., (© 2023. The Author(s).)

Inward-rectifier potassium channels (Kirs) are lipid-gated ion channels that differ from other K+ channels in that they allow K+ ions to flow more easily into, rather than out of, the cell. Inward rectification is known to result from endogenous magnesium ions or polyamines (e.g., spermine) binding to Kirs, resulting in a block of outward potassium currents, but questions remain regarding the structural and dynamic basis of the rectification process and lipid-dependent channel activation. Here, we present the results of long-timescale molecular dynamics simulations starting from a crystal structure of phosphatidylinositol 4,5-bisphosphate (PIP2)-bound chicken Kir2.2 with a non-conducting pore. After introducing a mutation (G178R) that is known to increase the open probability of a homologous channel, we were able to observe transitions to a stably open, ion-conducting pore, during which key conformational changes occurred in the main activation gate and the cytoplasmic domain. PIP2 binding appeared to increase stability of the pore in its open and conducting state, as PIP2 removal resulted in pore closure, with a median closure time about half of that with PIP2 present. To investigate structural details of inward rectification, we simulated spermine binding to and unbinding from the open pore conformation at positive and negative voltages, respectively, and identified a spermine-binding site located near a previously hypothesized site between the pore cavity and the selectivity filter. We also studied the effects of long-range electrostatics on conduction and spermine binding by mutating charged residues in the cytoplasmic domain and found that a finely tuned charge density, arising from basic and acidic residues within the cytoplasmic domain, modulated conduction and rectification., (© 2022 Jogini et al.)

Electronic monitoring devices (EMDs) have been trialled in interventions to improve inhaled corticosteroid adherence and clinical outcomes. This study sought to understand the perceptions and experiences of EMD end-users. Participants recruited into a six-month EMD study were invited to a semi-structured interview. Interviews were audio-recorded, transcribed verbatim and analysed using the framework approach. Twenty-eight participants (68% female, median age 47) were interviewed. Individuals described feeling responsible for their asthma control. Recent attacks motivated a desire to maintain control. Study participation led to increased awareness of asthma status and medication use. Several individuals were open to integrating digital monitoring data with other mHealth inputs, perceiving the potential to enhance communication with clinicians and empower self-management. Openness to data sharing was tied to expectations of transparent data use. Data supported integrating beliefs and habit formation to achieve behaviour change. There was a willingness for an integrated, platform-based approach to digital self-management., (© 2022. The Author(s).)

Proteins that are expressed on membrane surfaces or secreted are involved in all aspects of cellular and organismal life, and as such require extremely high fidelity during their synthesis and maturation. These proteins are synthesized at the endoplasmic reticulum (ER) where a dedicated quality control system (ERQC) ensures only properly matured proteins reach their destinations. An essential component of this process is the identification of proteins that fail to pass ERQC and their retrotranslocation to the cytosol for proteasomal degradation. This study by Wu et al . reports a cryo-electron microscopy (cryo-EM) structure of the five-protein channel through which aberrant proteins are extracted from the ER, providing insights into how recognition of misfolded proteins is coupled to their transport through a hydrophobic channel that acts to thin the ER membrane, further facilitating their dislocation to the cytosol 1 ., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2022 Faculty Opinions Ltd.)

A key step in the emergence of human pandemic influenza strains has been a switch in binding preference of the viral glycoprotein hemagglutinin (HA) from avian to human sialic acid (SA) receptors. The conformation of the bound SA varies substantially with HA sequence, and crystallographic evidence suggests that the bound SA is flexible, making it difficult to predict which mutations are responsible for changing HA-binding preference. We performed molecular dynamics (MD) simulations of SA analogues binding to various HAs and observed a dynamic equilibrium among structurally diverse receptor conformations, including conformations that have not been experimentally observed. Using one such novel conformation, we predicted─and experimentally confirmed─a set of mutations that substantially increased an HA's affinity for a human SA analogue. This prediction could not have been inferred from the existing crystal structures, suggesting that MD-generated HA-SA conformational ensembles could help researchers predict human-adaptive mutations, aiding surveillance of emerging pandemic threats.

Sex chromosomes have evolved repeatedly across the tree of life. Most work has focused on the loss of coding regions from sex-limited chromosomes through the accumulation of deleterious mutations. By comparison, less is known about how the regulatory landscape evolves. We review theories of how regulatory landscapes evolve on sex chromosomes and the overall impact they have on gametolog expression. We integrate empirical studies on sex chromosomes with theoretical work to synthesize how regulatory evolution could occur on sex chromosomes. Recent findings have revealed that downregulation of ancestral alleles is probably widespread on Y chromosomes and that regulatory evolution plays a key role in the evolution of sex chromosomes., Competing Interests: Declaration of interests The authors declare no conflicts of interest., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Airway smooth muscle (ASM) cells are fundamental to asthma pathogenesis, influencing bronchoconstriction, airway hyperresponsiveness and airway remodelling. The extracellular matrix (ECM) can influence tissue remodelling pathways; however, to date no study has investigated the effect of ASM ECM stiffness and cross-linking on the development of asthmatic airway remodelling. We hypothesised that transforming growth factor-β (TGF-β) activation by ASM cells is influenced by ECM in asthma and sought to investigate the mechanisms involved., Methods: This study combines in vitro and in vivo approaches: human ASM cells were used in vitro to investigate basal TGF-β activation and expression of ECM cross-linking enzymes. Human bronchial biopsies from asthmatic and nonasthmatic donors were used to confirm lysyl oxidase like 2 (LOXL2) expression in ASM. A chronic ovalbumin (OVA) model of asthma was used to study the effect of LOXL2 inhibition on airway remodelling., Results: We found that asthmatic ASM cells activated more TGF-β basally than nonasthmatic controls and that diseased cell-derived ECM influences levels of TGF-β activated. Our data demonstrate that the ECM cross-linking enzyme LOXL2 is increased in asthmatic ASM cells and in bronchial biopsies. Crucially, we show that LOXL2 inhibition reduces ECM stiffness and TGF-β activation in vitro , and can reduce subepithelial collagen deposition and ASM thickness, two features of airway remodelling, in an OVA mouse model of asthma., Conclusion: These data are the first to highlight a role for LOXL2 in the development of asthmatic airway remodelling and suggest that LOXL2 inhibition warrants further investigation as a potential therapy to reduce remodelling of the airways in severe asthma., Competing Interests: Conflict of interest: J. Ramis has a patent “Industrial Synthesis of Modified Crosslinkable Biopolymer” pending. Conflict of interest: R. Middlewick has nothing to disclose. Conflict of interest: F. Pappalardo has nothing to disclose. Conflict of interest: J.T. Cairns has nothing to disclose. Conflict of interest: I.D. Stewart has nothing to disclose. Conflict of interest: A.E. John has nothing to disclose. Conflict of interest: S-U-N. Naveed has nothing to disclose. Conflict of interest: R. Krishnan has nothing to disclose. Conflict of interest: S. Miller has nothing to disclose. Conflict of interest: D.E. Shaw has nothing to disclose. Conflict of interest: C.E. Brightling has nothing to disclose. Conflict of interest: L. Buttery has nothing to disclose. Conflict of interest: F. Rose has nothing to disclose. Conflict of interest: G. Jenkins reports personal fees and other (sponsored research agreement paid to institution) from Biogen, GlaxoSmithKline and MedImmune, personal fees from Galapagos, Heptares, Boehringer Ingelheim, Pliant, Roche/InterMune, PharmAkea, Bristol Myers Squibb, Chiesi and Roche/Promedior, other (sponsored research agreement paid to institution) from Galecto, other (collaborative awards) from RedX and Nordic Biosciences, other (advisory board membership) from NuMedii, outside the submitted work; is supported by a National Institute of Health Research Professorship (RP-2017-08-ST2-014); and is a trustee for Action for Pulmonary Fibrosis. Conflict of interest: S.R. Johnson reports grants from the Medical Research Council (MRC), during the conduct of the study; grants from the National Institute of Health Research, MRC and Pfizer, personal fees from AstraZeneca, outside the submitted work. Conflict of interest: A.L. Tatler reports personal fees for consultancy from Pliant Therapeutics, outside the submitted work., (Copyright ©The authors 2022.)

Introduction: Asthma is a heterogeneous disease with poorly defined phenotypes. Patients with severe asthma often receive multiple treatments including oral corticosteroids (OCS). Treatment may modify the observed metabotype, rendering it challenging to investigate underlying disease mechanisms. Here, we aimed to identify dysregulated metabolic processes in relation to asthma severity and medication., Methods: Baseline urine was collected prospectively from healthy participants (n=100), patients with mild-to-moderate asthma (n=87) and patients with severe asthma (n=418) in the cross-sectional U-BIOPRED cohort; 12-18-month longitudinal samples were collected from patients with severe asthma (n=305). Metabolomics data were acquired using high-resolution mass spectrometry and analysed using univariate and multivariate methods., Results: A total of 90 metabolites were identified, with 40 significantly altered (p<0.05, false discovery rate <0.05) in severe asthma and 23 by OCS use. Multivariate modelling showed that observed metabotypes in healthy participants and patients with mild-to-moderate asthma differed significantly from those in patients with severe asthma (p=2.6×10 -20 ), OCS-treated asthmatic patients differed significantly from non-treated patients (p=9.5×10 -4 ), and longitudinal metabotypes demonstrated temporal stability. Carnitine levels evidenced the strongest OCS-independent decrease in severe asthma. Reduced carnitine levels were associated with mitochondrial dysfunction via decreases in pathway enrichment scores of fatty acid metabolism and reduced expression of the carnitine transporter SLC22A5 in sputum and bronchial brushings., Conclusions: This is the first large-scale study to delineate disease- and OCS-associated metabolic differences in asthma. The widespread associations with different therapies upon the observed metabotypes demonstrate the need to evaluate potential modulating effects on a treatment- and metabolite-specific basis. Altered carnitine metabolism is a potentially actionable therapeutic target that is independent of OCS treatment, highlighting the role of mitochondrial dysfunction in severe asthma., Competing Interests: Conflict of interest: S.N. Reinke reports grants from Canadian Institutes of Health Research, during the conduct of the study. Conflict of interest: S. Naz has nothing to disclose. Conflict of interest: R. Chaleckis has nothing to disclose. Conflict of interest: H. Gallart-Ayala has nothing to disclose. Conflict of interest: J. Kolmert reports personal fees for consultancy from Gesynta Pharma AB, outside the submitted work. Conflict of interest: N.Z. Kermani has nothing to disclose. Conflict of interest: A. Tiotiu has nothing to disclose. Conflict of interest: D.I. Broadhurst has nothing to disclose. Conflict of interest: A. Lundqvist has nothing to disclose. Conflict of interest: H. Olsson is an employee and shareholder of AstraZeneca. Conflict of interest: M. Ström has nothing to disclose. Conflict of interest: Å.M. Wheelock has nothing to disclose. Conflict of interest: C. Gómez has nothing to disclose. Conflict of interest: M. Ericsson has nothing to disclose. Conflict of interest: A.R. Sousa has nothing to disclose. Conflict of interest: J.H. Riley works for and own shares in GlaxoSmithKline. Conflict of interest: S. Bates is an employee of Johnson & Johnson and has previously worked for and holds stock in GlaxoSmithKline. Conflict of interest: J. Scholfield reports grants from Innovative Medicines Initiative, during the conduct of the study; and is director and employee of TopMD Precision Medicine Ltd. Conflict of interest: M. Loza is an employee of and owns stock in Johnson & Johnson. Conflict of interest: F. Baribaud is a shareholder of Johnson & Johnson and a current employee of Bristol Myers Squibb. Conflict of interest: P.S. Bakke reports personal fees for advisory board work and lectures from AstraZeneca, and personal fees for lectures from Novartis and Boehringer Ingelheim, outside the submitted work. Conflict of interest: M. Caruso has nothing to disclose. Conflict of interest: P. Chanez reports grants and personal fees from AstraZeneca, ALK, Boehringer Ingelheim, Chiesi, Sanofi-Aventis, Novartis and GlaxoSmithKline, outside the submitted work. Conflict of interest: S.J. Fowler reports personal fees from AstraZeneca, Novartis, TEVA and Chiesi, outside the submitted work. Conflict of interest: T. Geiser has nothing to disclose. Conflict of interest: P. Howarth has nothing to disclose. Conflict of interest: I. Horvath has nothing to disclose. Conflict of interest: N. Krug has nothing to disclose. Conflict of interest: P. Montuschi has nothing to disclose. Conflict of interest: A. Behndig has nothing to disclose. Conflict of interest: F. Singer reports personal fees from Vertex Pharmaceuticals (CH) and Novartis, outside the submitted work. Conflict of interest: J. Musial has nothing to disclose. Conflict of interest: D.E. Shaw has nothing to disclose. Conflict of interest: B. Dahlén reports personal fees for advisory board work and lectures from AstraZeneca, TEVA and Sanofi, and grants from Novartis and GlaxoSmithKline, outside the submitted work. Conflict of interest: S. Hu has nothing to disclose. Conflict of interest: J. Lasky-Su has nothing to disclose. Conflict of interest: P.J. Sterk reports a public private grant from the Innovative Medicines Initiative (IMI) covered by the EU and EFPIA, during the conduct of the study. Conflict of interest: K.F. Chung has received honoraria for participating in advisory board meetings of GlaxoSmithKline, AstraZeneca, Roche, Novartis, Merck, Nocion and Shionogi regarding treatments for asthma, COPD and chronic cough and has also been remunerated for speaking engagements. Conflict of interest: R. Djukanovic reports receiving fees for lectures at symposia organised by Novartis, AstraZeneca and TEVA, consultation for TEVA and Novartis as member of advisory boards, and participation in a scientific discussion about asthma organised by GlaxoSmithKline; and is a co-founder and current consultant, and has shares in Synairgen, a University of Southampton spin out company. Conflict of interest: S-E. Dahlén reports personal fees for consultancy from AstraZeneca, Cayman Chemical, GlaxoSmithKline, Novartis, Merck, Regeneron, Sanofi and TEVA, outside the submitted work. Conflict of interest: I.M. Adcock has nothing to disclose. Conflict of interest: C.E. Wheelock has nothing to disclose., (Copyright ©The authors 2022.)

Although molecular dynamics (MD) simulations have been used extensively to study the structural dynamics of proteins, the role of MD simulation in studies of nucleic acid based systems has been more limited. One contributing factor to this disparity is the historically lower level of accuracy of the physical models used in such simulations to describe interactions involving nucleic acids. By modifying nonbonded and torsion parameters of a force field from the Amber family of models, we recently developed force field parameters for RNA that achieve a level of accuracy comparable to that of state-of-the-art protein force fields. Here we report force field parameters for DNA, which we developed by transferring nonbonded parameters from our recently reported RNA force field and making subsequent adjustments to torsion parameters. We have also modified the backbone charges in both the RNA and DNA parameter sets to make the treatment of electrostatics compatible with our recently developed variant of the Amber protein and ion force field. We name the force field resulting from the union of these three parameter sets (the new DNA parameters, the revised RNA parameters, and the existing protein and ion parameters) DES-Amber . Extensive testing of DES-Amber indicates that it can describe the thermal stability and conformational flexibility of single- and double-stranded DNA systems with a level of accuracy comparable to or, especially for disordered systems, exceeding that of state-of-the-art nucleic acid force fields. Finally, we show that, in certain favorable cases, DES-Amber can be used for long-timescale simulations of protein-nucleic acid complexes.

Background: Exacerbation-prone asthma is a feature of severe disease. However, the basis for its persistency remains unclear., Objectives: To determine the clinical and transcriptomic features of frequent exacerbators (FEs) and persistent FEs (PFEs) in the U-BIOPRED cohort., Methods: We compared features of FE (≥2 exacerbations in past year) to infrequent exacerbators (IE, <2 exacerbations) and of PFE with repeat ≥2 exacerbations during the following year to persistent IE (PIE). Transcriptomic data in blood, bronchial and nasal epithelial brushings, bronchial biopsies and sputum cells were analysed by gene set variation analysis for 103 gene signatures., Results: Of 317 patients, 62.4% had FE, of whom 63.6% had PFE, while 37.6% had IE, of whom 61.3% had PIE. Using multivariate analysis, FE was associated with short-acting beta-agonist use, sinusitis and daily oral corticosteroid use, while PFE was associated with eczema, short-acting beta-agonist use and asthma control index. CEA cell adhesion molecule 5 (CEACAM5) was the only differentially expressed transcript in bronchial biopsies between PE and IE. There were no differentially expressed genes in the other four compartments. There were higher expression scores for type 2, T-helper type-17 and type 1 pathway signatures together with those associated with viral infections in bronchial biopsies from FE compared to IE, while there were higher expression scores of type 2, type 1 and steroid insensitivity pathway signatures in bronchial biopsies of PFE compared to PIE., Conclusion: The FE group and its PFE subgroup are associated with poor asthma control while expressing higher type 1 and type 2 activation pathways compared to IE and PIE, respectively., (© 2022 The Authors. Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

Concerns have been raised over the association between bisphosphonates and atypical fractures in subtrochanteric and femoral shaft regions, but the potential risk of these fractures due to bisphosphonate use in asthma has not been examined., Introduction: Bisphosphonates are used as first-line treatment for osteoporosis; however, concerns have been raised over their association with atypical subtrochanteric (ST) and femoral shaft (FS) fractures. The potential risk of atypical ST/FS fractures from bisphosphonate use in asthma has not been examined., Methods: A nested case-control study was conducted using linked data from the Clinical Practice Research Datalink (CPRD) and Hospital Episode Statistics (HES) databases. Using an asthma cohort, we identified patients with atypical ST/FS fractures and sex, age, and practice-matched controls. Conditional logistic regression was used to determine the association between bisphosphonate exposure and atypical ST/FS fractures., Results: From a cohort of 69,074 people with asthma, 67 patients with atypical ST/FS fractures and 260 matched control subjects were identified. Of the case patients, 40.3% had received bisphosphonates as compared with 14.2% of the controls corresponding to an adjusted odds ratio (aOR) of 4.42 (95%CI, 2.98 to 8.53). The duration of use influenced the risk with long-term users to be at a greater risk (> 5 years vs no exposure; aOR = 7.67; 95%CI, 1.75 to 33.91). Drug withdrawal was associated with diminished odds of atypical ST/FS fractures., Conclusion: Regular review of bisphosphonates should occur in patients with asthma. The risks and benefits of bisphosphonate therapy should be carefully considered in consultation with the patient. To improve AFF prevention, early signs which may warrant imaging, such as prodromal thigh pain, should be discussed., (© 2021. International Osteoporosis Foundation and National Osteoporosis Foundation.)

Protein-protein interactions (PPIs) are ubiquitous biomolecular processes that are central to virtually all aspects of cellular function. Identifying small molecules that modulate specific disease-related PPIs is a strategy with enormous promise for drug discovery. The design of drugs to disrupt PPIs is challenging, however, because many potential drug-binding sites at PPI interfaces are "cryptic": When unoccupied by a ligand, cryptic sites are often flat and featureless, and thus not readily recognizable in crystal structures, with the geometric and chemical characteristics of typical small-molecule binding sites only emerging upon ligand binding. The rational design of small molecules to inhibit specific PPIs would benefit from a better understanding of how such molecules bind at PPI interfaces. To this end, we have conducted unbiased, all-atom MD simulations of the binding of four small-molecule inhibitors (SP4206 and three SP4206 analogs) to interleukin 2 (IL2)-which performs its function by forming a PPI with its receptor-without incorporating any prior structural information about the ligands' binding. In multiple binding events, a small molecule settled into a stable binding pose at the PPI interface of IL2, resulting in a protein-small-molecule binding site and pose virtually identical to that observed in an existing crystal structure of the IL2-SP4206 complex. Binding of the small molecule stabilized the IL2 binding groove, which when the small molecule was not bound emerged only transiently and incompletely. Moreover, free energy perturbation (FEP) calculations successfully distinguished between the native and non-native IL2-small-molecule binding poses found in the simulations, suggesting that binding simulations in combination with FEP may provide an effective tool for identifying cryptic binding sites and determining the binding poses of small molecules designed to disrupt PPI interfaces by binding to such sites., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: YS, VPM, AEL, ETK, and SS are former paid employees of D. E. Shaw Research; DES is the sole beneficial owner and Chief Scientist of D. E. Shaw Research.

The SARS-CoV-2 nonstructural proteins coordinate genome replication and gene expression. Structural analyses revealed the basis for coupling of the essential nsp13 helicase with the RNA-dependent RNA polymerase (RdRp) where the holo-RdRp and RNA substrate (the replication-transcription complex or RTC) associated with two copies of nsp13 (nsp13 2 -RTC). One copy of nsp13 interacts with the template-RNA in an opposing polarity to the RdRp and is envisaged to drive the RdRp backward on the RNA template (backtracking), prompting questions as to how the RdRp can efficiently synthesize RNA in the presence of nsp13. Here we use cryogenic-electron microscopy and molecular dynamics simulations to analyze the nsp13 2 -RTC, revealing four distinct conformational states of the helicases. The results indicate a mechanism for the nsp13 2 -RTC to turn backtracking on and off, using an allosteric mechanism to switch between RNA synthesis or backtracking in response to stimuli at the RdRp active site., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Rationale: Asthma phenotyping requires novel biomarker discovery., Objectives: To identify plasma biomarkers associated with asthma phenotypes by application of a new proteomic panel to samples from two well-characterised cohorts of severe (SA) and mild-to-moderate (MMA) asthmatics, COPD subjects and healthy controls (HCs)., Methods: An antibody-based array targeting 177 proteins predominantly involved in pathways relevant to inflammation, lipid metabolism, signal transduction and extracellular matrix was applied to plasma from 525 asthmatics and HCs in the U-BIOPRED cohort, and 142 subjects with asthma and COPD from the validation cohort BIOAIR. Effects of oral corticosteroids (OCS) were determined by a 2-week, placebo-controlled OCS trial in BIOAIR, and confirmed by relation to objective OCS measures in U-BIOPRED., Results: In U-BIOPRED, 110 proteins were significantly different, mostly elevated, in SA compared to MMA and HCs. 10 proteins were elevated in SA versus MMA in both U-BIOPRED and BIOAIR (alpha-1-antichymotrypsin, apolipoprotein-E, complement component 9, complement factor I, macrophage inflammatory protein-3, interleukin-6, sphingomyelin phosphodiesterase 3, TNF receptor superfamily member 11a, transforming growth factor-β and glutathione S-transferase). OCS treatment decreased most proteins, yet differences between SA and MMA remained following correction for OCS use. Consensus clustering of U-BIOPRED protein data yielded six clusters associated with asthma control, quality of life, blood neutrophils, high-sensitivity C-reactive protein and body mass index, but not Type-2 inflammatory biomarkers. The mast cell specific enzyme carboxypeptidase A3 was one major contributor to cluster differentiation., Conclusions: The plasma proteomic panel revealed previously unexplored yet potentially useful Type-2-independent biomarkers and validated several proteins with established involvement in the pathophysiology of SA., Competing Interests: Conflict of interest: M. Sparreman Mikus has nothing to disclose. Conflict of interest: J. Kolmert reports personal fees from Gesynta Pharma AB. Conflict of interest: L.I. Andersson has nothing to disclose. Conflict of interest: J. Östling has nothing to disclose. Conflict of interest: R.G. Knowles has nothing to disclose. Conflict of interest: C. Gómez has nothing to disclose. Conflict of interest: M. Ericsson has nothing to disclose. Conflict of interest: J-O. Thörngren has nothing to disclose. Conflict of interest: P. Emami Khoonsari has nothing to disclose. Conflict of interest: B. Dahlén reports personal fees from AstraZeneca, Teva, Sanofi and grants from Novartis and GlaxoSmithKline outside the submitted work. Conflict of interest: M. Kupczyk has nothing to disclose. Conflict of interest: B. De Meulder report grants from the Innovative Medicines Initiative during the conduct of the study. Conflict of interest: C. Auffray report grants from the Innovative Medicines Initiative during the conduct of the study. Conflict of interest: P.S. Bakke reports personal fees from GlaxoSmithKline, AstraZeneca, Boehringer Ingelheim and Chiesi outside the submitted work. Conflict of interest: B. Beghe reports personal fees from AstraZeneca, Boehringer Ingelheim, Menarini and GlaxoSmithKline outside the submitted work. Conflict of interest: E.H. Bel reports grants and personal fees from GlaxoSmithKline, AstraZeneca, Novartis, TEVA, Sanofi/Regeneron, Chiesi, and Sterna outside the submitted work. Conflict of interest: M. Caruso has nothing to disclose. Conflict of interest: P. Chanez has nothing to disclose. Conflict of interest: B. Chawes has nothing to disclose. Conflict of interest: S.J. Fowler has nothing to disclose. Conflict of interest: M. Gaga reports grants and personal fees from Novartis, Menarini, Merck Sharp & Dohme, BMS, Galapagos, and AstraZeneca outside the submitted work. Conflict of interest: T. Geiser has nothing to disclose. Conflict of interest: M. Gjomarkaj has nothing to disclose. Conflict of interest: I. Horváth reports grants from EFPIA during the conduct of the study, and personal fees from AstraZeneca, GlaxoSmithKline, Novartis, Boehringer-Ingelheim, Sandoz, Teva and Chiesi outside the submitted work. Conflict of interest: P.H. Howarth has nothing to disclose. Conflict of interest: S.L. Johnston reports personal fees from Virtus Respiratory Research, Myelo Therapeutics GmbH, Concert Pharmaceuticals, Bayer, Synairgen, Novartis, Boehringer Ingelheim, Chiesi, Gerson Lehrman Group, resTORbio, Bioforce, Materia Medical Holdings, PrepBio Pharma, Pulmotect, Virion Health, Lallemand Pharma and AstraZeneca outside the submitted work. In addition, Sebastian L. Johnston also has three patents (Anti-virus therapy for respiratory diseases, UK patent application No. GB 0405634.7, Interferon-Beta for Anti-Virus Therapy for Respiratory Diseases, International Patent Application No. PCT/ GB05/50031 and Interferon Lambda therapy for the treatment of respiratory disease, UK patent application No.6779645.9). Conflict of interest: G. Joos reports grants and personal fees from AstraZeneca, Bayer, Chiesi, Eureca vzw, GlaxoSmithKline and Teva outside the submitted work. Conflict of interest: N. Krug has nothing to disclose. Conflict of interest: P. Montuschi has nothing to disclose. Conflict of interest: J. Musial has nothing to disclose. Conflict of interest: E. Niżankowska-Mogilnicka has nothing to disclose. Conflict of interest: H.K. Olsson reports other support from AstraZeneca outside the submitted work. Conflict of interest: A. Papi reports grants, personal fees, non-financial support and others from GlaxoSmithKline, AstraZeneca, Boehringer Ingelheim, Chiesi, Teva, Mundipharma, Zambon, Novartis, Menarini, Sanofi/Regeneron, Roche, Fondazione Salvatore Maugeri, Chiesi and Edmond pharma outside the submitted work. Conflict of interest: K.F. Rabe reports grants and personal fees from AstraZeneca, Boehringer Ingelheim, Sanofi Aventis, MERCK SHARP & DOHME, Novartis, Orion Cooperation, Berlin Chemie, Roche, Chiesi and grants for research from the Ministry of Education and Science, Germany. Conflict of interest: T. Sandström has nothing to disclose. Conflict of interest: D.E. Shaw reports personal fees and non-financial support from GlaxoSmithKline, Novartis and AstraZeneca outside the submitted work. Conflict of interest: N.M. Siafakas has nothing to disclose. Conflict of interest: M. Uhlen has nothing to disclose. Conflict of interest: J.H. Riley is an employee and shareholder in GlaxoSmithKline. Conflict of interest: S. Bates is an employee and shareholder in GlaxoSmithKline. Conflict of interest: R.J.M. Middelveld reports grants from the Swedish Strategic Research Foundation, AstraZeneca, the Swedish Heart Lung Foundation and the Swedish Asthma and Allergy Association outside the submitted work. Conflict of interest: C.E. Wheelock has nothing to disclose. Conflict of interest: K.F. Chung reports grants and personal fees from GlaxoSmithKline, AstraZeneca, Novartis, Merck, Boehringer Ingelheim, Roche and Shionogi outside the submitted work. Conflict of interest: I.M. Adcock has nothing to disclose. Conflict of interest: P.J. Sterk reports grants to Amsterdam UMC from the public private Innovative Medicines Initiative (IMI) covered by the European Union (EU) and the European Federation of Pharmaceutical Industries and Associations (EFPIA) during the conduct of the study. Conflict of interest: R. Djukanovic reports receiving fees for lectures at symposia organised by Novartis, GlaxoSmithKline, AstraZeneca and Teva, consultation fees from Teva and Novartis; he is a co-founder and current consultant and has shares in Synairgen. Conflict of interest: P. Nilsson has nothing to disclose. Conflict of interest: S-E. Dahlén reports personal fees from AstraZeneca, Cayman Chemicals, GlaxoSmithKline, Novartis, Regeneron, Sanofi and Teva outside the submitted work. Conflict of interest: A. James has nothing to disclose., (Copyright ©The authors 2022.)

Intrinsically disordered proteins (IDPs) are implicated in many human diseases. They have generally not been amenable to conventional structure-based drug design, however, because their intrinsic conformational variability has precluded an atomic-level understanding of their binding to small molecules. Here we present long-time-scale, atomic-level molecular dynamics (MD) simulations of monomeric α-synuclein (an IDP whose aggregation is associated with Parkinson's disease) binding the small-molecule drug fasudil in which the observed protein-ligand interactions were found to be in good agreement with previously reported NMR chemical shift data. In our simulations, fasudil, when bound, favored certain charge-charge and π-stacking interactions near the C terminus of α-synuclein but tended not to form these interactions simultaneously, rather breaking one of these interactions and forming another nearby (a mechanism we term dynamic shuttling ). Further simulations with small molecules chosen to modify these interactions yielded binding affinities and key structural features of binding consistent with subsequent NMR experiments, suggesting the potential for MD-based strategies to facilitate the rational design of small molecules that bind with disordered proteins.

Effective inactivation of the HER2-HER3 tumor driver has remained elusive because of the challenging attributes of the pseudokinase HER3. We report a structure-function study of constitutive HER2-HER3 signaling to identify opportunities for targeting. The allosteric activation of the HER2 kinase domain (KD) by the HER3 KD is required for tumorigenic signaling and can potentially be targeted by allosteric inhibitors. ATP binding within the catalytically inactive HER3 KD provides structural rigidity that is important for signaling, but this is mimicked, not opposed, by small molecule ATP analogs, reported here in a bosutinib-bound crystal structure. Mutational disruption of ATP binding and molecular dynamics simulation of the apo KD of HER3 identify a conformational coupling of the ATP pocket with a hydrophobic AP-2 pocket, analogous to EGFR, that is critical for tumorigenic signaling and feasible for targeting. The value of these potential target sites is confirmed in tumor growth assays using gene replacement techniques., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)