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OBJECTIVE: To report the incidence of malignancy in gynaecological organs removed during radical cystectomy (RC). PATIENTS AND METHODS: A retrospective multicentre study of 1600 RCs at three high-volume institutions between January 2009 and March 2022 was performed. Pathological findings in gynaecological organs in female RC specimens were reviewed. Multivariable logistic regression analyses were used to identify predictors of malignant gynaecological organ involvement (GOI) at time of RC. RESULTS: Overall, 302 females with a median (interquartile range) age of 68 (61-75) years underwent RC for clinical (c)Ta-T4 bladder cancer. In all, 56 patients (18.5%) received neoadjuvant chemotherapy. Malignant GOI was seen in 20 patients (6.6%); the most common single sites of GOI were the uterus (five patients) and vaginal wall (four), followed by cervix (one), and ovaries (one). Nine patients had involvement of more than one gynaecological organ. No females had a primary gynaecological malignancy detected incidentally at RC. Patients with GOI were more likely to have cT3/T4 stage (P < 0.001), preoperative hydronephrosis (P = 0.004), lymphovascular invasion (P = 0.002), and squamous cell carcinoma (P = 0.005) than those without GOI. On multivariable analysis, cT4 stage was an independent predictor of malignant GOI (odds ratio 88.3, 95% confidence interval 10.1-1214; P < 0.001). CONCLUSION: To our knowledge, we present the largest multi-institutional study examining malignant GOI in females with bladder cancer undergoing RC. The rate of GOI at the time of RC is low and associated with higher clinical stage. In the absence of clinical or radiological evidence of sexual organ involvement, our results do not support their routine removal at the time of RC.
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Carcinoma de Células Escamosas , Carcinoma de Células Transicionales , Neoplasias de la Vejiga Urinaria , Humanos , Femenino , Anciano , Cistectomía/métodos , Neoplasias de la Vejiga Urinaria/patología , Vejiga Urinaria/patología , Estudios Retrospectivos , Carcinoma de Células Escamosas/patología , Carcinoma de Células Transicionales/patologíaRESUMEN
INTRODUCTION: Multiparametric MRI (mpMRI) parameters of pT3a prostate cancer have not been examined in large cohort studies. Therefore, we aimed to identify factors associated with up-staging of mpMRI cT3a in post-operative histopathological confirmation. METHODS: Retrospective analysis of a prospectively maintained database of a single UK cancer centre. Only cT3a cases who underwent robotic-assisted radical prostatectomy (RARP) were included (N = 383). MRI and specimen histopathology was reviewed independently by expert uro-radiologists and uro-histopathologists, respectively. Factors included age, BMI, prostate-specific antigen (PSA) level, biopsy international society of urological pathology (ISUP) grade, Prostate Imaging Reporting & Data System (PI-RADS®) score, tumour size, tumour coverage of gland (%), gland weight and surgical margins were analysed as predictors of pT3a prostate cancer. RESULTS: N = 383. Mean age 66 years (58-71), mean BMI 27.1 kg/m2 (25.0-30.0). 314 (82.0%) cases down- unchanged or down-staged, and 69 (18.0%) cases upstaged. PSA level (P = 0.002), PI-RADS score (P < 0.001) and ISUP grade (P < 0.001) are positively associated with upstage categories. ISUP grade ≥3 (OR 5.45, CI 1.88, 9.29, P < 0.002), PI-RADS score ≥4 (OR 3.92, CI 1.88-9.29, P < 0.001) and tumour coverage (OR 1.06, CI 1.05-1.08, P < 0.001) significantly positively associated with upstaging disease, with concurrent decreased probability of downstaging (OR 0.55, 0.14, 0.44, respectively, P < 0.05). Tumour coverage was positively correlated with increasing positive surgical margins (P < 0.05). Capsular contact > 15 mm was very unlikely to be upstaged (OR 0.36, CI 0.21-0.62, P < 0.001), aligning with published results past the widely accepted significant level for extracapsular disease on MRI. CONCLUSION: The study has identified PSA level, ISUP, PI-RADS score, tumour volume and percentage coverage are key predictive factors in cT3a upstaging. This study uniquely shows tumour coverage percentage as a predictor of cT3a upstaging on mpMRI. ISUP is the strongest predictor, followed by PI-RADS score and tumour coverage of gland. Multi-institutional studies are needed to confirm our findings.
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Estadificación de Neoplasias , Prostatectomía , Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/cirugía , Estudios Retrospectivos , Persona de Mediana Edad , Anciano , Hospitales de Alto Volumen , Imágenes de Resonancia Magnética Multiparamétrica , Procedimientos Quirúrgicos Robotizados , Imagen por Resonancia MagnéticaRESUMEN
The development of a versatile platform for the synthesis of 1,2-difunctionalized bicyclo[1.1.1]pentanes to potentially mimic ortho/meta-substituted arenes is described. The syntheses of useful building blocks bearing alcohol, amine, and carboxylic acid functional handles have been achieved from a simple common intermediate. Several ortho- and meta-substituted benzene analogs, as well as simple molecular matched pairs, have also been prepared using this platform. The results of in-depth ADME (absorption, distribution, metabolism, and excretion) investigations of these systems are presented, as well as computational studies which validate the ortho- or meta-character of these bioisosteres.
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Hidrocarburos Aromáticos/química , Pentanos/química , Bioensayo , Cristalografía por Rayos X , Hepatocitos/metabolismo , Humanos , Concentración 50 Inhibidora , Pentanos/síntesis química , EstereoisomerismoRESUMEN
INTRODUCTION: It is important for robotic surgery to be cost-effective, especially by reducing the length of stay (LOS). Therefore, we developed a protocol for day-case robot-assisted radical prostatectomy (RARP). This study aimed to validate this as a safe practice of care and to assess the potential benefits to the hospital and patient. METHODS: In this single-centre study, all patients booked for RARP between April 2022 and October 2022 were screened for suitability for day case. All tumour types were included. Exclusion criteria were a history of complex abdominal surgeries, salvage prostatectomy, body mass index (BMI) > 35 and patient living alone or > 150 km away from the hospital. All day-case RARPs were performed as a morning case with a protocol for review throughout the day with evening discharge if mobilising independently and eating/drinking well. The primary outcome of the study was success rate of discharge home on day of surgery (DOS) with secondary outcomes of readmissions and complications. A patient questionnaire was completed at home including both visual analogue scale (VAS) for pain and satisfaction rating. RESULTS: Forty-five patients underwent day-case RARP over a 6-month period with minimum of 30 days of follow-up. 41/45 (91%) had successful DOS discharge home. The four admissions overnight were due to dizziness, low oxygen saturation, intraoperative complications and a diagnosis of COVID-19. There were no readmissions and no 30-day complications. The most common issues at home were catheter discomfort and constipation with low mean VAS pain score and low nausea reported. The overall patient satisfaction rating was very high at 4.8/5, and 97% said they would recommend to a family member. The cost saving for the hospital was 400 pounds per patient. CONCLUSION: Day-case procedure is a viable, safe and efficient pathway for appropriately selected and counselled patients undergoing RARP.
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COVID-19 , Procedimientos Quirúrgicos Robotizados , Robótica , Masculino , Humanos , Procedimientos Quirúrgicos Robotizados/métodos , Alta del Paciente , Prostatectomía/métodos , Dolor , Resultado del TratamientoRESUMEN
The glucocorticoid receptor (GR) is a ligand-dependent transcription factor that plays a central role in inflammation. The GR activity is also modulated via protein-protein interactions, including binding of 14-3-3 proteins induced by GR phosphorylation. However, the specific phosphorylation sites on the GR that trigger these interactions and their functional consequences are less clear. Hence, we sought to examine this system in more detail. We used phosphorylated GR peptides, biophysical studies, and X-ray crystallography to identify key residues within the ligand-binding domain of the GR, T524 and S617, whose phosphorylation results in binding of the representative 14-3-3 protein 14-3-3ζ. A kinase screen identified misshapen-like kinase 1 (MINK1) as responsible for phosphorylating T524 and Rho-associated protein kinase 1 for phosphorylating S617; cell-based approaches confirmed the importance of both GR phosphosites and MINK1 but not Rho-associated protein kinase 1 alone in inducing GR-14-3-3 binding. Together our results provide molecular-level insight into 14-3-3-mediated regulation of the GR and highlight both MINK1 and the GR-14-3-3 axis as potential targets for future therapeutic intervention.
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Proteínas 14-3-3/metabolismo , Regulación de la Expresión Génica , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores de Glucocorticoides/metabolismo , Treonina/metabolismo , Proteínas 14-3-3/genética , Células HEK293 , Humanos , Mutación , Fosforilación , Unión Proteica , Proteínas Serina-Treonina Quinasas/genética , Receptores de Glucocorticoides/genética , Treonina/genética , Activación TranscripcionalRESUMEN
OBJECTIVES: To report clinical and functional outcomes for patients who have undergone salvage robot-assisted seminal vesicle excision (RA-SVE) for the focal treatment of isolated seminal vesical (SV) recurrence after treatment for prostate cancer by low-dose-rate brachytherapy. PATIENTS AND METHODS: Patients with rising prostate-specific antigen (PSA) after low-dose-rate prostate brachytherapy (LDR-PB) underwent multi-parametric magnetic resonance imaging (mp-MRI) of the prostate and 11 C-Choline or 68 Ga-prostate-specific membrane antigen (68 Ga-PSMA) positron emission tomography/computed tomography (PET/CT) scan, followed by targeted transperineal biopsy of the prostate and SVs. Isolated SV recurrence were identified in 17 (0.38%) LDR-PB patients. These 17 patients were offered RA-SVE. RESULTS: The median total operative time was 90 min and blood loss 50 mL with no postoperative transfusions required. The median hospital stay was 1 day. No intra- or postoperative complications were documented. Continence status was unaffected, no patient required urinary pads. Postoperative pathology confirmed SV invasion in all specimens. Surgical margins were positive in seven (41%) patients. All patients had at least one positive imaging study, although three (18%) mp-MRI and five (29%) PET/CT assessments were negative. One (6%) pre-SVE biopsy was also negative but with positive imaging. Salvage SVE failure, defined as three consecutive PSA rises or the need for further treatment, occurred in six patients of whom three had a positive margin. Overall failure-free survival rates were 86%, 67%, and 53% at 1, 2, and 3 years after SVE, respectively. CONCLUSIONS: Salvage RA-SVE appears to be a safe focal treatment, with very low morbidity, for patients with localised SV recurrence after LDR-PB. It permits deferral of androgen deprivation therapy in selected patients. Bilateral SVE is mandatory. This surgical option should be considered in patients with isolated prostate cancer recurrence to the SV.
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Braquiterapia , Neoplasias de la Próstata , Procedimientos Quirúrgicos Robotizados , Vesículas Seminales , Antagonistas de Andrógenos , Biopsia , Humanos , Masculino , Recurrencia Local de Neoplasia/patología , Tomografía Computarizada por Tomografía de Emisión de Positrones , Próstata/patología , Antígeno Prostático Específico , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/cirugía , Terapia Recuperativa/métodos , Vesículas Seminales/patología , Vesículas Seminales/cirugíaRESUMEN
Contrary to expectation N-aryl pyrrolidinones (and isosteric imidazolinones and oxazolinones) are more lipophilic and less soluble than the corresponding piperidinones (tetrahydropyrimidinones and oxazinones). Exploration of the basis for these results uncovered a subtle interplay of steric and electronic effects that result in different conformations for the two classes of compounds which drive the observed effects.
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Pirrolidinonas , Conformación MolecularRESUMEN
α-Branched heteroaryl amines are prevalent motifs in drugs and are typically prepared through C-N bond formation. In contrast, C-C bond-forming approaches to branched amines may dramatically expand available chemical space but are rarely pursued in parallel format due to a lack of established library protocols. Methods for the synthesis of α-branched heteroaryl amines via aldimine addition have been evaluated for compatibility with parallel synthesis. In situ activation of aliphatic carboxylic acids as redox-active esters enables Zn-mediated decarboxylative radical imine addition to access aliphatic-branched heterobenzylic amines. In situ activation of (hetero)aryl bromides via Li-halogen exchange enables heteroaryl-lithium addition to imines to access (hetero)benzhydryl amines. Condensation of heteroaryl amines with heteroaryl aldehydes provides aldimines which may be intercepted with aryl Grignard reagents to provide modular access to (hetero)benzhydryl amines. These protocols minimize synthetic step count and maximize accessible design space, enhancing access to α-branched heteroaryl amines for medicinal chemistry.
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Aminas , Química Farmacéutica , Aldehídos/química , Aminas/química , Ácidos Carboxílicos , Iminas/químicaRESUMEN
The synthesis of structurally diverse heterocycles for chemical space exploration was achieved via the cascade reactions of indigo with propargylic electrophiles. New pyrazinodiindolodione, naphthyridinedione, azepinodiindolone, oxazinoindolone and pyrrolodione products were prepared in one pot reactions by varying the leaving group (-Cl, -Br, -OMs, -OTs) or propargyl terminal functionality (-H, -Me, -Ph, -Ar). Mechanistic and density functional theory studies revealed that the unsaturated propargyl moiety can behave as an electrophile when aromatic terminal substitutions are made, and therefore competes with leaving group substitution for new outcomes. Selected products from the cascade reactions were investigated for their absorption and fluorescence properties, including transient absorption spectroscopy. This revealed polarity dependent excited state relaxation pathways, fluorescence, and triplet formation, thus highlighting these reactions as a means to access diverse functional materials rapidly.
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We have discovered a class of PI3Kγ inhibitors exhibiting over 1,000-fold selectivity over PI3Kα and PI3Kß. On the basis of X-ray crystallography, hydrogen-deuterium exchange-mass spectrometry and surface plasmon resonance experiments we propose that the cyclopropylethyl moiety displaces the DFG motif of the enzyme away from the adenosine tri-phosphate binding site, inducing a large conformational change in both the kinase- and helical domains of PI3Kγ. Site directed mutagenesis explained how the conformational changes occur. Our results suggest that these cyclopropylethyl substituted compounds selectively inhibit the active state of PI3Kγ, which is unique to these compounds and to the PI3Kγ isoform, explaining their excellent potency and unmatched isoform selectivity that were confirmed in cellular systems. This is the first example of a Class I PI3K inhibitor achieving its selectivity by affecting the DFG motif in a manner that bears similarity to DFG in/out for type II protein kinase inhibitors.
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Fosfatidilinositol 3-Quinasa Clase Ib/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Adenosina Trifosfatasas , Sitios de Unión , Fosfatidilinositol 3-Quinasa Clase I/antagonistas & inhibidores , Fosfatidilinositol 3-Quinasa Clase I/metabolismo , Cristalografía por Rayos X , Humanos , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Ftalimidas , Unión Proteica , Conformación Proteica , Isoformas de Proteínas/fisiología , Inhibidores de Proteínas Quinasas , Especificidad por SustratoRESUMEN
Regulation of inflammation is a central part of the maintenance of homeostasis by the immune system. One important class of regulatory protein that has been shown to have effects on the inflammatory process are the 14-3-3 proteins. Herein we describe the roles that have been identified for 14-3-3 in regulation of the inflammatory response. These roles encompass regulation of the response that affect inflammation at the genetic, molecular and cellular levels. At a genetic level 14-3-3 is involved in the regulation of multiple transcription factors and affects the transcription of key effectors of the immune response. At a molecular level many of the constituent parts of the inflammatory process, such as pattern recognition receptors, protease activated receptors and cytokines are regulated through phosphorylation and recognition by 14-3-3 whilst disruption of the recognition processes has been observed to result in clinical syndromes. 14-3-3 is also involved in the regulation of cell proliferation and differentiation, this has been shown to affect the immune system, particularly T- and B-cells. Finally, we discuss how abnormal levels of 14-3-3 contribute to undesirable immune responses and chronic inflammatory conditions.
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Proteínas 14-3-3/metabolismo , Inflamación/metabolismo , Proteínas 14-3-3/genética , Animales , Humanos , Inflamación/genética , Unión ProteicaRESUMEN
Current guidelines around preclinical screening for drug-induced arrhythmias require the measurement of the potency of block of voltage-gated potassium channel subtype 11.1 (Kv11.1) as a surrogate for risk. A shortcoming of this approach is that the measured IC50 of Kv11.1 block varies widely depending on the voltage protocol used in electrophysiological assays. In this study, we aimed to investigate the factors that contribute to these differences and to identify whether it is possible to make predictions about protocol-dependent block that might facilitate the comparison of potencies measured using different assays. Our data demonstrate that state preferential binding, together with drug-binding kinetics and trapping, is an important determinant of the protocol dependence of Kv11.1 block. We show for the first time that differences in IC50 measured between protocols occurs in a predictable way, such that machine-learning algorithms trained using a selection of simple voltage protocols can indeed predict protocol-dependent potency. Furthermore, we also show that the preference of a drug for binding to the open versus the inactivated state of Kv11.1 can also be inferred from differences in IC50 values measured between protocols. Our work therefore identifies how state preferential drug binding is a major determinant of the protocol dependence of IC50 values measured in preclinical Kv11.1 assays. It also provides a novel method for quantifying the state dependence of Kv11.1 drug binding that will facilitate the development of more complete models of drug binding to Kv11.1 and improve our understanding of proarrhythmic risk associated with compounds that block Kv11.1.
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Bioensayo/métodos , Canal de Potasio ERG1/genética , Canal de Potasio ERG1/metabolismo , Bloqueadores de los Canales de Potasio/farmacología , Animales , Arritmias Cardíacas/inducido químicamente , Células CHO , Línea Celular , Cricetulus , Fenómenos Electrofisiológicos/efectos de los fármacos , Humanos , Concentración 50 Inhibidora , Cinética , Bloqueadores de los Canales de Potasio/efectos adversosRESUMEN
The human ether-a-go-go related gene (hERG) encodes the pore-forming subunit of the rapid component of the delayed rectifier K(+) channel, Kv11.1, which are expressed in the heart, various brain regions, smooth muscle cells, endocrine cells, and a wide range of tumor cell lines. However, it is the role that Kv11.1 channels play in the heart that has been best characterized, for two main reasons. First, it is the gene product involved in chromosome 7-associated long QT syndrome (LQTS), an inherited disorder associated with a markedly increased risk of ventricular arrhythmias and sudden cardiac death. Second, blockade of Kv11.1, by a wide range of prescription medications, causes drug-induced QT prolongation with an increase in risk of sudden cardiac arrest. In the first part of this review, the properties of Kv11.1 channels, including biogenesis, trafficking, gating, and pharmacology are discussed, while the second part focuses on the pathophysiology of Kv11.1 channels.
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Canales de Potasio Éter-A-Go-Go/metabolismo , Sistema de Conducción Cardíaco/metabolismo , Potasio/metabolismo , Animales , Canal de Potasio ERG1 , Canales de Potasio Éter-A-Go-Go/química , Canales de Potasio Éter-A-Go-Go/efectos de los fármacos , Canales de Potasio Éter-A-Go-Go/genética , Predisposición Genética a la Enfermedad , Sistema de Conducción Cardíaco/efectos de los fármacos , Sistema de Conducción Cardíaco/fisiopatología , Humanos , Activación del Canal Iónico , Síndrome de QT Prolongado/etiología , Síndrome de QT Prolongado/metabolismo , Síndrome de QT Prolongado/fisiopatología , Fenotipo , Bloqueadores de los Canales de Potasio/farmacología , Conformación Proteica , Transporte de Proteínas , Relación Estructura-ActividadRESUMEN
Historically accessed through two-electron, anionic chemistry, ketones, alcohols, and amines are of foundational importance to the practice of organic synthesis. After placing this work in proper historical context, this Article reports the development, full scope, and a mechanistic picture for a strikingly different way of forging such functional groups. Thus, carboxylic acids, once converted to redox-active esters (RAEs), can be utilized as formally nucleophilic coupling partners with other carboxylic derivatives (to produce ketones), imines (to produce benzylic amines), or aldehydes (to produce alcohols). The reactions are uniformly mild, operationally simple, and, in the case of ketone synthesis, broad in scope (including several applications to the simplification of synthetic problems and to parallel synthesis). Finally, an extensive mechanistic study of the ketone synthesis is performed to trace the elementary steps of the catalytic cycle and provide the end-user with a clear and understandable rationale for the selectivity, role of additives, and underlying driving forces involved.
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Alcoholes/química , Alcoholes/síntesis química , Aminas/química , Aminas/síntesis química , Cetonas/química , Cetonas/síntesis química , Técnicas de Química Sintética , Radicales Libres/químicaRESUMEN
Conservation of long-distance migratory species poses unique challenges. Migratory connectivity, that is, the extent to which groupings of individuals at breeding sites are maintained in wintering areas, is frequently used to evaluate population structure and assess use of key habitat areas. However, for species with complex or variable annual cycle movements, this traditional bimodal framework of migratory connectivity may be overly simplistic. Like many other waterfowl, sea ducks often travel to specific pre- and post-breeding sites outside their nesting and wintering areas to prepare for migration by feeding extensively and, in some cases, molting their flight feathers. These additional migrations may play a key role in population structure, but are not included in traditional models of migratory connectivity. Network analysis, which applies graph theory to assess linkages between discrete locations or entities, offers a powerful tool for quantitatively assessing the contributions of different sites used throughout the annual cycle to complex spatial networks. We collected satellite telemetry data on annual cycle movements of 672 individual sea ducks of five species from throughout eastern North America and the Great Lakes. From these data, we constructed a multi-species network model of migratory patterns and site use over the course of breeding, molting, wintering, and migratory staging. Our results highlight inter- and intra-specific differences in the patterns and complexity of annual cycle movement patterns, including the central importance of staging and molting sites in James Bay, the St. Lawrence River, and southern New England to multi-species annual cycle habitat linkages, and highlight the value of Long-tailed Ducks (Calengula haemalis) as an umbrella species to represent the movement patterns of multiple sea duck species. We also discuss potential applications of network migration models to conservation prioritization, identification of population units, and integrating different data streams.
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Patos , Ecosistema , Migración Animal , Animales , Lagos , New England , Estaciones del AñoRESUMEN
Congenital mutations in the cardiac Kv11.1 channel can cause long QT syndrome type 2 (LQTS2), a heart rhythm disorder associated with sudden cardiac death. Mutations act either by reducing protein expression at the membrane and/or by perturbing the intricate gating properties of Kv11.1 channels. A number of clinical LQTS2-associated mutations have been reported in the first transmembrane segment (S1) of Kv11.1 channels, but the role of this region of the channel is largely unexplored. In part, this is due to problems defining the extent of the S1 helix, as a consequence of its low sequence homology with other Kv family members. Here, we used NMR spectroscopy and electrophysiological characterization to show that the S1 of Kv11.1 channels extends seven helical turns, from Pro-405 to Phe-431, and is flanked by unstructured loops. Functional analysis suggests that pre-S1 loop residues His-402 and Tyr-403 play an important role in regulating the kinetics and voltage dependence of channel activation and deactivation. Multiple residues within the S1 helix also play an important role in fine-tuning the voltage dependence of activation, regulating slow deactivation, and modulating C-type inactivation of Kv11.1 channels. Analyses of LQTS2-associated mutations in the pre-S1 loop or S1 helix of Kv11.1 channels demonstrate perturbations to both protein expression and most gating transitions. Thus, S1 region mutations would reduce both the action potential repolarizing current passed by Kv11.1 channels in cardiac myocytes, as well as the current passed in response to premature depolarizations that normally helps protect against the formation of ectopic beats.
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Canal de Potasio ERG1/metabolismo , Activación del Canal Iónico/fisiología , Miocitos Cardíacos/metabolismo , Sustitución de Aminoácidos , Animales , Canal de Potasio ERG1/genética , Humanos , Síndrome de QT Prolongado/genética , Síndrome de QT Prolongado/metabolismo , Mutación Missense , Estructura Secundaria de Proteína , Xenopus laevisRESUMEN
Macrocycles are of increasing interest as chemical probes and drugs for intractable targets like protein-protein interactions, but the determinants of their cell permeability and oral absorption are poorly understood. To enable rational design of cell-permeable macrocycles, we generated an extensive data set under consistent experimental conditions for more than 200 non-peptidic, de novo-designed macrocycles from the Broad Institute's diversity-oriented screening collection. This revealed how specific functional groups, substituents and molecular properties impact cell permeability. Analysis of energy-minimized structures for stereo- and regioisomeric sets provided fundamental insight into how dynamic, intramolecular interactions in the 3D conformations of macrocycles may be linked to physicochemical properties and permeability. Combined use of quantitative structure-permeability modeling and the procedure for conformational analysis now, for the first time, provides chemists with a rational approach to design cell-permeable non-peptidic macrocycles with potential for oral absorption.
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Compuestos Macrocíclicos/química , Compuestos Macrocíclicos/farmacocinética , Células CACO-2 , Humanos , Estructura Molecular , Permeabilidad , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
Slow deactivation of Kv11.1 channels is critical for its function in the heart. The S4-S5 linker, which joins the voltage sensor and pore domains, plays a critical role in this slow deactivation gating. Here, we use NMR spectroscopy to identify the membrane-bound surface of the S4S5 linker, and we show that two highly conserved tyrosine residues within the KCNH subfamily of channels are membrane-associated. Site-directed mutagenesis and electrophysiological analysis indicates that Tyr-542 interacts with both the pore domain and voltage sensor residues to stabilize activated conformations of the channel, whereas Tyr-545 contributes to the slow kinetics of deactivation by primarily stabilizing the transition state between the activated and closed states. Thus, the two tyrosine residues in the Kv11.1 S4S5 linker play critical but distinct roles in the slow deactivation phenotype, which is a hallmark of Kv11.1 channels.
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Membrana Celular/química , Canal de Potasio ERG1/química , Activación del Canal Iónico/fisiología , Péptidos/química , Animales , Membrana Celular/genética , Membrana Celular/metabolismo , Canal de Potasio ERG1/genética , Canal de Potasio ERG1/metabolismo , Femenino , Humanos , Resonancia Magnética Nuclear Biomolecular , Péptidos/genética , Péptidos/metabolismo , XenopusRESUMEN
A novel class of potent PI3Kδ inhibitors with >1000-fold selectivity against other class I PI3K isoforms is described. Optimization of the substituents on a triazole aminopyrazine scaffold, emerging from an in-house PI3Kα program, turned moderately selective PI3Kδ compounds into highly potent and selective PI3Kδ inhibitors. These efforts resulted in a series of aminopyrazines with PI3Kδ IC50⩽1nM in the enzyme assay, some of the most selective PI3Kδ inhibitors published to date, with a cell potency in a JeKo-cell assay of 20-120nM.