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1.
Pharmacotherapy ; 44(3): 241-248, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38140830

RESUMEN

INTRODUCTION: Falls are the leading cause of injury in older individuals, with intracranial hemorrhage (ICH) being a common complication. Anticoagulants, such as vitamin K antagonist and direct oral anticoagulants, are increasingly utilized, and clinicians may question the necessity of reversal in patients with minor ICH, especially in the setting of increased risk of adverse events. This study aimed to identify a population of patients with minor traumatic ICH at low risk for poor-neurologic status where anticoagulant reversal may not improve outcomes. METHODS: This retrospective cohort study utilized data accessed from 35 trauma centers from 2018 to 2021. Patients included had a preinjury anticoagulant regimen, ICH due to blunt trauma, Glasgow Coma Scale score of 15, an Abbreviated Injury Scale (AIS) head score from 2 to 4, and an AIS of ≤1 for non-head regions within 24 h of hospital arrival. Patients were excluded if they required an emergent neurosurgical procedure or were on a preinjury purinergic-P2 receptor-12 protein (P2Y12) inhibitor. The primary outcome was the rate of in-hospital mortality or hospice. RESULTS: There were 654 patients on preinjury anticoagulation who were included with a minor traumatic ICH without neurologic deficits. Overall, 263 patients were reversed and 391 were not reversed. Twelve (4.6%) patients with in-hospital mortality or hospice were reversed compared with 19 (4.91%) patients who were not reversed (p = 0.861). A composite of hospital complications occurred in 21 (8%) reversed patients and 34 (8.7%) not reversed patients (p = 0.748). The average intensive care unit length of stay was 1.4 ± 3.4 days in the reversed group and 1.1 ± 1.8 days in the not reversed group (p = 0.069). CONCLUSION: This study found no difference in hospital outcomes between patients with minor traumatic ICH on oral anticoagulants who were neurologically intact that were reversed versus those who were not reversed. Further studies should continue to define the subset of traumatic ICH patients who may not require reversal of anticoagulation.


Asunto(s)
Anticoagulantes , Hemorragia Intracraneal Traumática , Humanos , Anciano , Anticoagulantes/efectos adversos , Estudios Retrospectivos , Hemorragia Intracraneal Traumática/inducido químicamente , Hemorragia/inducido químicamente , Hemorragias Intracraneales/inducido químicamente
3.
Nat Neurosci ; 26(9): 1505-1515, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37563294

RESUMEN

Idiopathic autism spectrum disorder (ASD) is highly heterogeneous, and it remains unclear how convergent biological processes in affected individuals may give rise to symptoms. Here, using cortical organoids and single-cell transcriptomics, we modeled alterations in the forebrain development between boys with idiopathic ASD and their unaffected fathers in 13 families. Transcriptomic changes suggest that ASD pathogenesis in macrocephalic and normocephalic probands involves an opposite disruption of the balance between excitatory neurons of the dorsal cortical plate and other lineages such as early-generated neurons from the putative preplate. The imbalance stemmed from divergent expression of transcription factors driving cell fate during early cortical development. While we did not find genomic variants in probands that explained the observed transcriptomic alterations, a significant overlap between altered transcripts and reported ASD risk genes affected by rare variants suggests a degree of gene convergence between rare forms of ASD and the developmental transcriptome in idiopathic ASD.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Masculino , Humanos , Trastorno Autístico/genética , Trastorno del Espectro Autista/patología , Neuronas/metabolismo , Neurogénesis , Prosencéfalo/metabolismo , Organoides/metabolismo
4.
Plant Commun ; 4(6): 100639, 2023 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-37322867

RESUMEN

Jasmonates (JAs) are plant hormones with crucial roles in development and stress resilience. They activate MYC transcription factors by mediating the proteolysis of MYC inhibitors called JAZ proteins. In the absence of JA, JAZ proteins bind and inhibit MYC through the assembly of MYC-JAZ-Novel Interactor of JAZ (NINJA)-TPL repressor complexes. However, JAZ and NINJA are predicted to be largely intrinsically unstructured, which has precluded their experimental structure determination. Through a combination of biochemical, mutational, and biophysical analyses and AlphaFold-derived ColabFold modeling, we characterized JAZ-JAZ and JAZ-NINJA interactions and generated models with detailed, high-confidence domain interfaces. We demonstrate that JAZ, NINJA, and MYC interface domains are dynamic in isolation and become stabilized in a stepwise order upon complex assembly. By contrast, most JAZ and NINJA regions outside of the interfaces remain highly dynamic and cannot be modeled in a single conformation. Our data indicate that the small JAZ Zinc finger expressed in Inflorescence Meristem (ZIM) motif mediates JAZ-JAZ and JAZ-NINJA interactions through separate surfaces, and our data further suggest that NINJA modulates JAZ dimerization. This study advances our understanding of JA signaling by providing insights into the dynamics, interactions, and structure of the JAZ-NINJA core of the JA repressor complex.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/química , Proteínas Represoras/metabolismo , Ciclopentanos/metabolismo
5.
Cereb Cortex ; 33(10): 6320-6334, 2023 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-36573438

RESUMEN

Difficulty with attention is an important symptom in many conditions in psychiatry, including neurodiverse conditions such as autism. There is a need to better understand the neurobiological correlates of attention and leverage these findings in healthcare settings. Nevertheless, it remains unclear if it is possible to build dimensional predictive models of attentional state in a sample that includes participants with neurodiverse conditions. Here, we use 5 datasets to identify and validate functional connectome-based markers of attention. In dataset 1, we use connectome-based predictive modeling and observe successful prediction of performance on an in-scan sustained attention task in a sample of youth, including participants with a neurodiverse condition. The predictions are not driven by confounds, such as head motion. In dataset 2, we find that the attention network model defined in dataset 1 generalizes to predict in-scan attention in a separate sample of neurotypical participants performing the same attention task. In datasets 3-5, we use connectome-based identification and longitudinal scans to probe the stability of the attention network across months to years in individual participants. Our results help elucidate the brain correlates of attentional state in youth and support the further development of predictive dimensional models of other clinically relevant phenotypes.


Asunto(s)
Atención , Trastorno del Espectro Autista , Encéfalo , Conectoma , Humanos , Adolescente , Trastorno del Espectro Autista/fisiopatología , Trastorno del Espectro Autista/psicología , Conjuntos de Datos como Asunto , Masculino , Femenino , Encéfalo/fisiopatología , Encéfalo/ultraestructura
6.
ACS Omega ; 7(38): 34665-34675, 2022 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-36188294

RESUMEN

Ornithine decarboxylase (ODC) is a rate-limiting enzyme for the synthesis of polyamines (PAs). PAs are required for proliferation, and increased ODC activity is associated with cancer and neural over-proliferation. ODC levels and activity are therefore tightly regulated, including through the ODC-specific inhibitor, antizyme AZ1. Recently, ODC G84R has been reported as a partial loss-of-function variant that is associated with intellectual disability and seizures. However, G84 is distant from both the catalytic center and the ODC homodimerization interface. To understand how G84R modulates ODC activity, we have determined the crystal structure of ODC G84R in both the presence and the absence of the cofactor pyridoxal 5-phosphate. The structures show that the replacement of G84 by arginine leads to hydrogen bond formation of R84 with F420, the last residue of the ODC C-terminal helix, a structural element that is involved in the AZ1-mediated proteasomal degradation of ODC. In contrast, the catalytic center is essentially indistinguishable from that of wildtype ODC. We therefore reanalyzed the catalytic activity of ODC G84R and found that it is rescued when the protein is purified in the presence of a reducing agent to mimic the reducing environment of the cytoplasm. This suggests that R84 may exert its neurological effects not through reducing ODC catalytic activity but through misregulation of its AZ1-mediated proteasomal degradation.

7.
J Pain Palliat Care Pharmacother ; 36(2): 112-116, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35471125

RESUMEN

Capsaicin is a topical pain reliever that has been evaluated by randomized controlled trials (RCTs) as a potential adjunctive therapy for treating unmitigated fibromyalgia. Therefore, a review of English articles using PubMed and Embase was conducted from January 1, 1990 to February 9, 2022 in order to evaluate the utility of capsaicin for improvement of sleep quality and fatigue associated with fibromyalgia. The search terms included: "fibromyalgia" and "capsaicin". Articles included were RCTs evaluating capsaicin in adult patients with fibromyalgia. Two studies met criteria and included 175 patients that received either capsaicin or placebo for an average total treatment length of 5 weeks. The treatment outcomes assessed were changes in quality of sleep and fatigue by several standardized modalities. These include visual analog scale (VAS) of sleep quality and fatigue, fatigue severity scale, Pittsburgh Sleep Quality Index (PSQI), and global subjective improvement. Both studies demonstrated no changes in sleep quality, but one study did find a significant difference in global subjective improvement. This same study also found a significant improvement in fatigue. Consequently, this existing evidence is insufficient to warrant recommending capsaicin as adjunctive therapy for improvement in sleep quality and fatigue. Future studies regarding capsaicin therapy for fibromyalgia are needed.


Asunto(s)
Fibromialgia , Adulto , Capsaicina/uso terapéutico , Fatiga/tratamiento farmacológico , Fatiga/etiología , Fibromialgia/complicaciones , Fibromialgia/tratamiento farmacológico , Humanos , Dimensión del Dolor , Calidad del Sueño
8.
Autism Res ; 15(7): 1336-1347, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35388596

RESUMEN

Executive functioning (EF) deficits co-occur frequently with autism spectrum disorder (ASD) and have a long-term detrimental impact on quality of life of children and their families. Timely identification of risk for EF vulnerabilities may hasten access to early intervention and alleviate their long-term consequences. This study examines (1) if EF deficits are elevated in toddlers with ASD compared to nonautistic siblings of children with ASD, typically developing (TYP) toddlers, and toddlers with atypical developmental presentation; and (2) if EF deficits have a detrimental effect on adaptive functioning in ASD. Participants were recruited between September 2014 and October 2019 and included 73 toddlers with ASD, 33 nonautistic siblings of children with ASD, 35 toddlers with atypical development, and 28 TYP toddlers matched on chronological age (M = 39.01 months, SD = 3.11). EF deficits were measured using the BRIEF-P; adaptive skills were measured using the VABS-II. Whenever appropriate, analyses were controlled for MSEL verbal and nonverbal developmental quotient, ADOS-2 autism severity scores, and sex. Analyses revealed that toddlers with ASD exhibited elevated BRIEF-P scores across all domains compared to each of the three comparison groups. Higher BRIEF-P scores were associated with lower adaptive social, communication, and daily living skills while controlling for symptom severity, verbal and nonverbal functioning, and sex. In conclusion, marked vulnerabilities in EF are already present in 3-year-old toddlers with ASD and are predictive of the level of adaptive functioning in ASD. EF vulnerabilities in toddlers should be targeted for intervention to improve long-term outcomes in ASD. LAY SUMMARY: Many children with autism experience vulnerabilities in executive functioning (EF), which may include challenges with inhibition, working memory, cognitive flexibility, and planning. The study shows that these vulnerabilities can already be detected at age three and that their presence is linked with lower social, communication, and daily living skills. Screening children with ASD for EF challenges and helping those who have difficulties may improve their long-term outcomes.


Asunto(s)
Trastorno del Espectro Autista , Disfunción Cognitiva , Preescolar , Función Ejecutiva/fisiología , Humanos , Calidad de Vida , Hermanos
9.
Biochem J ; 478(23): 4137-4149, 2021 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-34796899

RESUMEN

Ornithine decarboxylase (ODC) is the rate-limiting enzyme for the synthesis of polyamines (PAs). PAs are oncometabolites that are required for proliferation, and pharmaceutical ODC inhibition is pursued for the treatment of hyperproliferative diseases, including cancer and infectious diseases. The most potent ODC inhibitor is 1-amino-oxy-3-aminopropane (APA). A previous crystal structure of an ODC-APA complex indicated that APA non-covalently binds ODC and its cofactor pyridoxal 5-phosphate (PLP) and functions by competing with the ODC substrate ornithine for binding to the catalytic site. We have revisited the mechanism of APA binding and ODC inhibition through a new crystal structure of APA-bound ODC, which we solved at 2.49 Šresolution. The structure unambiguously shows the presence of a covalent oxime between APA and PLP in the catalytic site, which we confirmed in solution by mass spectrometry. The stable oxime makes extensive interactions with ODC but cannot be catabolized, explaining APA's high potency in ODC inhibition. In addition, we solved an ODC/PLP complex structure with citrate bound at the substrate-binding pocket. These two structures provide new structural scaffolds for developing more efficient pharmaceutical ODC inhibitors.


Asunto(s)
Inhibidores de la Ornitina Descarboxilasa/metabolismo , Ornitina Descarboxilasa/metabolismo , Propilaminas/metabolismo , Humanos , Unión Proteica , Dominios Proteicos
10.
Curr Pharm Teach Learn ; 13(11): 1464-1470, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34799060

RESUMEN

INTRODUCTION: Survey results from 2016 and 2018 at the University of Michigan College of Pharmacy highlighted mental health concerns for the student population, including struggles with depression, anxiety, and academic distress. This led to creation of a pilot well-being elective course for first year doctor of pharmacy students. This article describes how this course was assessed and adapted for the future. METHODS: The well-being elective course used a course-specific survey and the Brief Inventory of Thriving to assess student outcomes. The course-specific survey was based upon the course objectives and the University of Michigan Common Agenda for Well-Being. Both surveys were given pre- and post-course to identify change. RESULTS: Course survey results illustrated an improvement in student well-being over a single semester. Compared with pre-course responses, students who completed the course were significantly more likely to agree with statements indicating they had strong time management skills, resilience to manage the fluctuations of life, were able to make thoughtful choices to reduce harm and promote well-being, and overall rated their well-being as excellent. Additionally, nearly all students felt a sense of strengthened community with peers and faculty within the course, better able to recognize or refer a peer for help, and felt the course contributed to their overall well-being. CONCLUSIONS: Implementation of this well-being elective pilot course provided students the tools and resources to improve upon their overall well-being in an effort to address anxiety, depression, and academic distress.


Asunto(s)
Educación en Farmacia , Servicios Farmacéuticos , Farmacia , Estudiantes de Farmacia , Humanos , Farmacéuticos
11.
Science ; 373(6553): 413-419, 2021 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-34437114

RESUMEN

Adenosine monophosphate (AMP)-activated protein kinase (AMPK) regulates metabolism in response to the cellular energy states. Under energy stress, AMP stabilizes the active AMPK conformation, in which the kinase activation loop (AL) is protected from protein phosphatases, thus keeping the AL in its active, phosphorylated state. At low AMP:ATP (adenosine triphosphate) ratios, ATP inhibits AMPK by increasing AL dynamics and accessibility. We developed conformation-specific antibodies to trap ATP-bound AMPK in a fully inactive, dynamic state and determined its structure at 3.5-angstrom resolution using cryo-electron microscopy. A 180° rotation and 100-angstrom displacement of the kinase domain fully exposes the AL. On the basis of the structure and supporting biophysical data, we propose a multistep mechanism explaining how adenine nucleotides and pharmacological agonists modulate AMPK activity by altering AL phosphorylation and accessibility.


Asunto(s)
Proteínas Quinasas Activadas por AMP/química , Proteínas Quinasas Activadas por AMP/inmunología , Proteínas Quinasas Activadas por AMP/metabolismo , Adenosina Monofosfato/metabolismo , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/metabolismo , Microscopía por Crioelectrón , Humanos , Fragmentos Fab de Inmunoglobulinas , Modelos Moleculares , Fosforilación , Conformación Proteica , Dominios Proteicos , Ingeniería de Proteínas
12.
J Am Acad Child Adolesc Psychiatry ; 60(1): 166-175, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32061926

RESUMEN

OBJECTIVE: Although some eye-tracking studies demonstrate atypical attention to faces by 6 months of age in autism spectrum disorder (ASD), behavioral studies in early infancy return largely negative results. We examined the effects of context and diagnosis on attention to faces during face-to-face live interactions in infants at high familial risk (HR) and low familial risk (LR) for ASD. METHOD: Participants were 6-, 9-, and 12-month-old siblings of children with ASD who were later determined to have ASD (n = 21), other developmental challenges (HR-C; n = 74), or typical development (TD) (HR-TD; n = 32), and low-risk, typically developing controls (LR-TD; n = 49). Infants were administered the social orienting probes task, consisting of five conditions: dyadic bid, song, peek-a-boo, tickle, and toy play. Attention to an unfamiliar examiner's face was coded by blinded raters from video recordings. RESULTS: At all ages, the ASD group spent less time looking at the examiner's face than the HR-C, HR-TD, and LR-TD groups during the Dyadic Bid and Tickle conditions (all p <.05), but not during the Song, Peek-a-Boo, or Toy Play conditions (all p >.23). Lower attention to faces during Dyadic Bid and Tickle conditions was significantly correlated with higher severity of autism symptoms at 18 months. CONCLUSION: During the prodromal stages of the disorder, infants with ASD exhibited subtle impairments in attention to faces of interactive partners during interactions involving eye contact and child-directed speech (with and without physical contact), but not in contexts involving singing, familiar anticipatory games, or toy play. Considering the convergence with eye-tracking findings on limited attention to faces in infants later diagnosed with ASD, reduced attention to faces of interactive partners in specific contexts may constitute a promising candidate behavioral marker of ASD in infancy.


Asunto(s)
Trastorno del Espectro Autista , Niño , Humanos , Lactante , Riesgo , Hermanos
13.
Sci Rep ; 10(1): 21855, 2020 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-33318557

RESUMEN

Performing functional magnetic resonance imaging (fMRI) scans of children can be a difficult task, as participants tend to move while being scanned. Head motion represents a significant confound in fMRI connectivity analyses. One approach to limit motion has been to use shorter MRI protocols, though this reduces the reliability of results. Hence, there is a need to implement methods to achieve high-quality, low-motion data while not sacrificing data quantity. Here we show that by using a mock scan protocol prior to a scan, in conjunction with other in-scan steps (weighted blanket and incentive system), it is possible to achieve low-motion fMRI data in pediatric participants (age range: 7-17 years old) undergoing a 60 min MRI session. We also observe that motion is low during the MRI protocol in a separate replication group of participants, including some with autism spectrum disorder. Collectively, the results indicate it is possible to conduct long scan protocols in difficult-to-scan populations and still achieve high-quality data, thus potentially allowing more reliable fMRI findings.


Asunto(s)
Imagen por Resonancia Magnética , Adolescente , Niño , Femenino , Humanos , Masculino
14.
Chem Sci ; 11(8): 2260-2268, 2020 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-32190280

RESUMEN

Peroxisome proliferator-activated receptor γ (PPARγ) is a key regulator of glucose homeostasis and lipid metabolism, and an important target for the development of modern anti-diabetic drugs. However, current PPARγ-targeting anti-diabetic drugs such as classical thiazolidinediones (TZDs) are associated with undesirable side effects. To address this concern, we here describe the structure-based design, synthesis, identification and detailed in vitro and in vivo characterization of a novel, decanoic acid (DA)-based and selective PPARγ modulator (SPPARγM), VSP-77, especially (S)-VSP-77, as the potential "hit" for the development of improved and safer anti-diabetic therapeutics. We have also determined the co-crystal structure of the PPARγ ligand-binding domain (LBD) in complex with two molecules of (S)-VSP-77, which reveal a previously undisclosed allosteric binding mode. Overall, these findings not only demonstrate the therapeutic advantage of (S)-VSP-77 over current TZD drugs and representative partial agonist INT131, but also provide a rational basis for the development of future SPPARγMs as safe and highly efficacious anti-diabetic drugs.

15.
J Int Neuropsychol Soc ; 26(7): 725-732, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32178755

RESUMEN

OBJECTIVE: Executive functions (EF) drive health and educational outcomes and therefore are increasingly common treatment targets. Most treatment trials rely on questionnaires to capture meaningful change because ecologically valid, pediatric performance-based EF tasks are lacking. The Executive Function Challenge Task (EFCT) is a standardized, treatment-sensitive, objective measure which assesses flexibility and planning in the context of provocative social interactions, making it a "hot" EF task. METHOD: We investigate the structure, reliability, and validity of the EFCT in youth with autism (Autism Spectrum Disorder; n = 129), or attention deficit hyperactivity disorder with flexibility problems (n = 93), and typically developing (TD; n = 52) youth. RESULTS: The EFCT can be coded reliably, has a two-factor structure (flexibility and planning), and adequate internal consistency and consistency across forms. Unlike a traditional performance-based EF task (verbal fluency), it shows significant correlations with parent-reported EF, indicating ecological validity. EFCT performance distinguishes youth with known EF problems from TD youth and is not significantly related to visual pattern recognition, or social communication/understanding in autistic children. CONCLUSIONS: The EFCT demonstrates adequate reliability and validity and may provide developmentally appropriate, treatment-sensitive, and ecologically valid assessment of "hot" EF in youth. It can be administered in controlled settings by masked administrators.


Asunto(s)
Función Ejecutiva , Psicometría/normas , Adolescente , Trastorno por Déficit de Atención con Hiperactividad/psicología , Trastorno del Espectro Autista/psicología , Niño , Femenino , Humanos , Masculino , Memoria a Corto Plazo , Pruebas Neuropsicológicas , Reproducibilidad de los Resultados , Interacción Social
16.
J Am Acad Child Adolesc Psychiatry ; 57(11): 828-836.e2, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30392624

RESUMEN

OBJECTIVE: There is a prevailing notion that children with autism spectrum disorder (ASD) exhibit intense negative and attenuated positive emotions, although the empirical evidence regarding their emotional expressiveness (EE) is limited. Given the importance of emotions in shaping social and cognitive development, we examined intensity and valence of EE and links between EE and autism severity and parent-reported temperament in ASD. METHOD: Toddlers (aged 21.2 months) with ASD (n = 43), developmental delay (DD, n = 16), and typical development (TD, n = 40) underwent standardized probes designed to induce anger, joy, and fear. Intensity of EE through facial and vocal channels were coded offline. Autism severity and temperament were quantified using the Autism Diagnostic Observation Schedule-2 (ADOS-2) and Early Childhood Behavior Questionnaire (ECBQ). RESULTS: The ASD group exhibited less intense fear compared to both the DD and TD groups, more intense anger than DD but not TD, with no differences in joy intensity. All groups showed similar levels of incongruous negative EE. Intensity of fear and anger were not associated with severity of autism symptoms, but lower intensity of joy was related to greater autism severity. Expressed fear and joy were associated with temperament. CONCLUSION: The study provides no support for a negative emotionality bias in ASD. Instead, toddlers with ASD display a muted response to threat and an accentuated response to goal blockage, whereas the ability to express positive emotions appears intact. Negative emotionality and social disability dimensions are independent. The study demonstrates the complexity of EE in ASD and motivates investigations into underlying mechanisms as well as its role in shaping complex phenotypes of affected children.


Asunto(s)
Trastorno del Espectro Autista/fisiopatología , Discapacidades del Desarrollo/fisiopatología , Emociones/fisiología , Temperamento/fisiología , Conducta Infantil , Preescolar , Femenino , Humanos , Lactante , Masculino
17.
J Biol Chem ; 293(44): 16994-17007, 2018 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-30206123

RESUMEN

AMP-activated protein kinase (AMPK) is a master regulator of energy homeostasis and a promising drug target for managing metabolic diseases such as type 2 diabetes. Many pharmacological AMPK activators, and possibly unidentified physiological metabolites, bind to the allosteric drug and metabolite (ADaM) site at the interface between the kinase domain (KD) in the α-subunit and the carbohydrate-binding module (CBM) in the ß-subunit. Here, using double electron-electron resonance (DEER) spectroscopy, we demonstrate that the CBM-KD interaction is partially dissociated and the interface highly disordered in the absence of pharmacological ADaM site activators as inferred from a low depth of modulation and broad DEER distance distributions. ADaM site ligands such as 991, and to a lesser degree phosphorylation, stabilize the KD-CBM association and strikingly reduce conformational heterogeneity in the ADaM site. Our findings that the ADaM site, formed by the KD-CBM interaction, can be modulated by diverse ligands and by phosphorylation suggest that it may function as a hub for integrating regulatory signals.


Asunto(s)
Proteínas Quinasas Activadas por AMP/química , Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Adenosina Monofosfato/química , Adenosina Monofosfato/metabolismo , Regulación Alostérica , Bencimidazoles/química , Bencimidazoles/metabolismo , Benzoatos/química , Benzoatos/metabolismo , Sitios de Unión , Dominio Catalítico , Cristalografía por Rayos X , Humanos , Ligandos , Conformación Proteica , Dominios Proteicos
18.
Nature ; 560(7720): 666-670, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30135577

RESUMEN

Frizzled receptors (FZDs) are class-F G-protein-coupled receptors (GPCRs) that function in Wnt signalling and are essential for developing and adult organisms1,2. As central mediators in this complex signalling pathway, FZDs serve as gatekeeping proteins both for drug intervention and for the development of probes in basic and in therapeutic research. Here we present an atomic-resolution structure of the human Frizzled 4 receptor (FZD4) transmembrane domain in the absence of a bound ligand. The structure reveals an unusual transmembrane architecture in which helix VI is short and tightly packed, and is distinct from all other GPCR structures reported so far. Within this unique transmembrane fold is an extremely narrow and highly hydrophilic pocket that is not amenable to the binding of traditional GPCR ligands. We show that such a pocket is conserved across all FZDs, which may explain the long-standing difficulties in the development of ligands for these receptors. Molecular dynamics simulations on the microsecond timescale and mutational analysis uncovered two coupled, dynamic kinks located at helix VII that are involved in FZD4 activation. The stability of the structure in its ligand-free form, an unfavourable pocket for ligand binding and the two unusual kinks on helix VII suggest that FZDs may have evolved a novel ligand-recognition and activation mechanism that is distinct from that of other GPCRs.


Asunto(s)
Receptores Frizzled/química , Sitios de Unión , Cristalografía por Rayos X , Cisteína/metabolismo , Proteínas Dishevelled/metabolismo , Receptores Frizzled/genética , Humanos , Ligandos , Modelos Moleculares , Simulación de Dinámica Molecular , Dominios Proteicos , Vía de Señalización Wnt
19.
J Autism Dev Disord ; 48(4): 1069-1080, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29181689

RESUMEN

Given the emphasis on early screening for ASD, it is crucial to examine the concordance between parent report and clinician observation of autism-related behaviors. Similar items were compared from the First Year Inventory (Baranek et al. First-Year Inventory (FYI) 2.0. University of North Carolina, Chapel Hill, 2003), a parent screener for ASD, and the ADOS-2 Toddler Module (Lord et al. 2013), a standardized ASD diagnostic tool. Measures were administered concurrently to 12-month-olds at high and low risk for ASD. Results suggest that clinicians and parents rated behaviors similarly. In addition, both informants rated high-risk infants as more impaired in several social-communication behaviors. Furthermore, the format of questions impacted agreement across observers. These findings have implications for the development of a new generation of screening instruments for ASD.


Asunto(s)
Trastorno del Espectro Autista/diagnóstico , Trastorno del Espectro Autista/psicología , Disentimientos y Disputas , Diagnóstico Precoz , Padres , Médicos , Trastorno del Espectro Autista/enfermería , Femenino , Humanos , Lactante , Masculino , Médicos/psicología , Conducta Social
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