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1.
Cell ; 157(6): 1292-1308, 2014 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-24906148

RESUMEN

Beige fat, which expresses the thermogenic protein UCP1, provides a defense against cold and obesity. Although a cold environment is the physiologic stimulus for inducing beige fat in mice and humans, the events that lead from the sensing of cold to the development of beige fat remain poorly understood. Here, we identify the efferent beige fat thermogenic circuit, consisting of eosinophils, type 2 cytokines interleukin (IL)-4/13, and alternatively activated macrophages. Genetic loss of eosinophils or IL-4/13 signaling impairs cold-induced biogenesis of beige fat. Mechanistically, macrophages recruited to cold-stressed subcutaneous white adipose tissue (scWAT) undergo alternative activation to induce tyrosine hydroxylase expression and catecholamine production, factors required for browning of scWAT. Conversely, administration of IL-4 to thermoneutral mice increases beige fat mass and thermogenic capacity to ameliorate pre-established obesity. Together, our findings have uncovered the efferent circuit controlling biogenesis of beige fat and provide support for its targeting to treat obesity.


Asunto(s)
Tejido Adiposo Pardo/metabolismo , Eosinófilos/metabolismo , Interleucina-13/metabolismo , Interleucina-4/metabolismo , Macrófagos/metabolismo , Transducción de Señal , Adipocitos Marrones/metabolismo , Animales , Catecolaminas/metabolismo , Frío , Interleucina-13/genética , Interleucina-4/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Células Mieloides/metabolismo , Obesidad/metabolismo , Receptores CCR2/metabolismo , Factor de Transcripción STAT6/metabolismo , Termogénesis
2.
Nat Immunol ; 15(5): 423-30, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24681566

RESUMEN

Obesity and resistance to insulin are closely associated with the development of low-grade inflammation. Interleukin 6 (IL-6) is linked to obesity-associated inflammation; however, its role in this context remains controversial. Here we found that mice with an inactivated gene encoding the IL-6Rα chain of the receptor for IL-6 in myeloid cells (Il6ra(Δmyel) mice) developed exaggerated deterioration of glucose homeostasis during diet-induced obesity, due to enhanced resistance to insulin. Tissues targeted by insulin showed increased inflammation and a shift in macrophage polarization. IL-6 induced expression of the receptor for IL-4 and augmented the response to IL-4 in macrophages in a cell-autonomous manner. Il6ra(Δmyel) mice were resistant to IL-4-mediated alternative polarization of macrophages and exhibited enhanced susceptibility to lipopolysaccharide (LPS)-induced endotoxemia. Our results identify signaling via IL-6 as an important determinant of the alternative activation of macrophages and assign an unexpected homeostatic role to IL-6 in limiting inflammation.


Asunto(s)
Endotoxemia/inmunología , Resistencia a la Insulina , Interleucina-6/metabolismo , Activación de Macrófagos , Macrófagos/inmunología , Obesidad/inmunología , Animales , Células Cultivadas , Humanos , Resistencia a la Insulina/genética , Resistencia a la Insulina/inmunología , Interleucina-4/inmunología , Interleucina-6/genética , Lipopolisacáridos/inmunología , Activación de Macrófagos/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mutación/genética , Receptores de Interleucina-6/genética , Transducción de Señal/genética
3.
PLoS Pathog ; 19(8): e1011603, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37624867

RESUMEN

Antibodies result from the competition of B cell lineages evolving under selection for improved antigen recognition, a process known as affinity maturation. High-affinity antibodies to pathogens such as HIV, influenza, and SARS-CoV-2 are frequently reported to arise from B cells whose receptors, the precursors to antibodies, are encoded by particular immunoglobulin alleles. This raises the possibility that the presence of particular germline alleles in the B cell repertoire is a major determinant of the quality of the antibody response. Alternatively, initial differences in germline alleles' propensities to form high-affinity receptors might be overcome by chance events during affinity maturation. We first investigate these scenarios in simulations: when germline-encoded fitness differences are large relative to the rate and effect size variation of somatic mutations, the same germline alleles persistently dominate the response of different individuals. In contrast, if germline-encoded advantages can be easily overcome by subsequent mutations, allele usage becomes increasingly divergent over time, a pattern we then observe in mice experimentally infected with influenza virus. We investigated whether affinity maturation might nonetheless strongly select for particular amino acid motifs across diverse genetic backgrounds, but we found no evidence of convergence to similar CDR3 sequences or amino acid substitutions. These results suggest that although germline-encoded specificities can lead to similar immune responses between individuals, diverse evolutionary routes to high affinity limit the genetic predictability of responses to infection and vaccination.


Asunto(s)
COVID-19 , Animales , Ratones , COVID-19/genética , SARS-CoV-2/genética , Anticuerpos , Alelos , Células Germinativas
4.
J Org Chem ; 89(11): 8299-8304, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38747531

RESUMEN

We report the high-yielding, large-scale, one-pot synthesis of two versatile building blocks (1-Cl and 1-Br) for the regioselective synthesis of a variety of 2,3,5-trisubstituted pyridines from inexpensive materials. These molecules are readily derivatized at positions 2, 3, and 5. These building blocks can also be used for the synthesis of fused pyrido-oxazines and for the synthesis of 2,3,4,5-tetrasubstituted pyridines.

5.
Org Biomol Chem ; 22(6): 1234-1244, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38240351

RESUMEN

Herein we report a method for affording 2-benzyl benzoxazoles from substituted styrenes and 2-nitrophenols. The success of this method relies on the use of simple reagents, namely elemental sulfur and DABCO. A combination of identical reagents was utilized for the annulation of styrenes with N,N-dialkyl-3-nitroanilines to afford 2-benzyl benzothiazoles. Overall, benzoxazoles and benzothiazoles bearing useful functionalities such as halogens, amines, and heterocyclic groups were isolated in moderate to good yields. Our methods are a rare example of divergent transformations of substituted nitroarenes towards 2-benzyl benzoxazoles and benzothiazoles.

6.
Mol Cell Proteomics ; 20: 100136, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34391887

RESUMEN

Immune checkpoint inhibitors and adoptive lymphocyte transfer-based therapies have shown great therapeutic potential in cancers with high tumor mutational burden (TMB), such as melanoma, but not in cancers with low TMB, such as mutant epidermal growth factor receptor (EGFR)-driven lung adenocarcinoma. Precision immunotherapy is an unmet need for most cancers, particularly for cancers that respond inadequately to immune checkpoint inhibitors. Here, we employed large-scale MS-based proteogenomic profiling to identify potential immunogenic human leukocyte antigen (HLA) class I-presented peptides in melanoma and EGFR-mutant lung adenocarcinoma. Similar numbers of peptides were identified from both tumor types. Cell line and patient-specific databases (DBs) were constructed using variants identified from whole-exome sequencing. A de novo search algorithm was used to interrogate the HLA class I immunopeptidome MS data. We identified 12 variant peptides and several classes of tumor-associated antigen-derived peptides. We constructed a cancer germ line (CG) antigen DB with 285 antigens. This allowed us to identify 40 class I-presented CG antigen-derived peptides. The class I immunopeptidome comprised more than 1000 post-translationally modified (PTM) peptides representing 58 different PTMs, underscoring the critical role PTMs may play in HLA binding. Finally, leveraging de novo search algorithm and an annotated long noncoding RNA (lncRNA) DB, we developed a novel lncRNA-encoded peptide discovery pipeline to identify 44 lncRNA-derived peptides that are presented by class I. We validated tandem MS spectra of select variant, CG antigen, and lncRNA-derived peptides using synthetic peptides and performed HLA class I-binding assays to demonstrate binding to class I proteins. In summary, we provide direct evidence of HLA class I presentation of a large number of variant and tumor-associated peptides in both low and high TMB cancer. These results can potentially be useful for precision immunotherapies, such as vaccine or adoptive cell therapies in melanoma and EGFR-mutant lung cancers.


Asunto(s)
Adenocarcinoma del Pulmón/metabolismo , Antígenos de Neoplasias/metabolismo , Antígenos de Histocompatibilidad Clase I/metabolismo , Neoplasias Pulmonares/metabolismo , Melanoma/metabolismo , Péptidos/metabolismo , Adenocarcinoma del Pulmón/genética , Anciano , Antígenos de Neoplasias/genética , Línea Celular Tumoral , Receptores ErbB/genética , Antígenos de Histocompatibilidad Clase I/genética , Humanos , Neoplasias Pulmonares/genética , Masculino , Melanoma/genética , Mutación , Péptidos/genética , Proteogenómica
7.
Cerebellum ; 20(3): 430-438, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33400236

RESUMEN

Upper limb function for people with Friedreich ataxia determines capacity to participate in daily activities. Current upper limb measures available do not fully capture impairments related to Friedreich ataxia. We have developed an objective measure, the Ataxia Instrumented Measure-Spoon (AIM-S), which consists of a spoon equipped with a BioKin wireless motion capture device, and algorithms that analyse these signals, to measure ataxia of the upper limb during the pre-oral phase of eating. The aim of this study was to evaluate the AIM-S as a sensitive and functionally relevant clinical outcome for use in clinical trials. A prospective longitudinal study evaluated the capacity of the AIM-S to detect change in upper limb function over 48 weeks. Friedreich ataxia clinical severity, performance on the Nine-Hole Peg Test and Box and Block Test and responses to a purpose-designed questionnaire regarding acceptability of AIM-S were recorded. Forty individuals with Friedreich ataxia and 20 control participants completed the baseline assessment. Thirty individuals with Friedreich ataxia completed the second assessment. The sensitivity of the AIM-S to detect deterioration in upper limb function was greater than other measures. Patient-reported outcomes indicated the AIM-S reflected a daily activity and was more enjoyable to complete than other assessments. The AIM-S is a more accurate, less variable measure of upper limb function in Friedreich ataxia than existing measures. The AIM-S is perceived by individuals with Friedreich ataxia to be related to everyday life and will permit individuals who are non-ambulant to be included in future clinical trials.


Asunto(s)
Ataxia de Friedreich/diagnóstico , Extremidad Superior/fisiopatología , Actividades Cotidianas , Adolescente , Adulto , Algoritmos , Niño , Preescolar , Progresión de la Enfermedad , Ingestión de Alimentos , Femenino , Ataxia de Friedreich/fisiopatología , Ataxia de Friedreich/rehabilitación , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Movimiento , Estudios Prospectivos , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Resultado del Tratamiento , Tecnología Inalámbrica , Adulto Joven
8.
Org Biomol Chem ; 19(21): 4726-4732, 2021 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-33969845

RESUMEN

Pyrido-fused quinazolinones were synthesized via copper-catalyzed cascade C(sp2)-H amination and annulation of 2-aminoarylmethanols with isoquinolines or pyridines. The transformation proceeded readily in the presence of a commercially available CuCl2 catalyst with molecular oxygen as a green oxidant. Moreover, the dehydrogenative cross-coupling of 2-aminoarylmethanols with tetrahydroisoquinolines was explored, in which CuBr exhibited higher catalytic activity than CuCl2. Broad substrate scope with good tolerance of functionalities was observed under the optimized reaction conditions. The bioactive naturally occurring alkaloid rutaecarpine could be obtained by this strategy. The remarkable feature of this protocol is that complicated heterocyclic structures are readily achieved in a single synthetic step from easily accessible reactants and catalysts. This pathway to pyrido-fused quinazolinones would be complementary to existing protocols.

9.
Int J Mol Sci ; 22(3)2021 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-33572687

RESUMEN

AMP-activated protein kinase (AMPK) plays a crucial role in the regulation of energy homeostasis in both peripheral metabolic organs and the central nervous system. Recent studies indicated that p-Coumaric acid (CA), a hydroxycinnamic phenolic acid, potentially activated the peripheral AMPK pathway to exert beneficial effects on glucose metabolism in vitro. However, CA's actions on central AMPK activity and whole-body glucose homeostasis have not yet been investigated. Here, we reported that CA exhibited different effects on peripheral and central AMPK activation both in vitro and in vivo. Specifically, while CA treatment promoted hepatic AMPK activation, it showed an inhibitory effect on hypothalamic AMPK activity possibly by activating the S6 kinase. Furthermore, CA treatment enhanced hypothalamic leptin sensitivity, resulting in increased proopiomelanocortin (POMC) expression, decreased agouti-related peptide (AgRP) expression, and reduced daily food intake. Overall, CA treatment improved blood glucose control, glucose tolerance, and insulin sensitivity. Together, these results suggested that CA treatment enhanced hypothalamic leptin signaling and whole-body glucose homeostasis, possibly via its differential effects on AMPK activation.


Asunto(s)
Proteínas Quinasas Activadas por AMP/efectos de los fármacos , Ácidos Cumáricos/farmacología , Glucosa/metabolismo , Leptina/metabolismo , Transducción de Señal/efectos de los fármacos , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Homeostasis/efectos de los fármacos , Hipotálamo/metabolismo , Resistencia a la Insulina , Ratones , Proopiomelanocortina/metabolismo
10.
Acta Paediatr ; 109(12): 2685-2691, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32181924

RESUMEN

AIM: To evaluate effect and costs of pertussis vaccination at Vietnam National Children's Hospital. METHODS: Pertussis cases were defined by positive laboratory tests of children under 5 years January 2015-June 2018, and data on patient characteristics, clinical data and hospitalisation costs were collected through patient records. RESULTS: Of 909 inpatients, 400 (44%) were <2 months, the age for first DPT vaccination, and mechanical ventilation was more common than in children >2 months (9% vs 4%, OR = 2.3, CI 1.3-3.9), as well as persistent cough (99%), violent cough (87%) and pneumonia (91%). Comparing non-vaccinated (172 cases, 19%) and DPT vaccinated patients >2 months of age hospitalisation was 106-fold higher (149.6 vs 1.39 per 100 000 population), and proportion of severe patients, length of hospital stay and hospitalisation costs were significantly greater (23.9% vs 12.8%; 13 vs 10 days; 826 USD vs 582 USD, CI 23-423, P = .03). CONCLUSION: Incidence and proportion of complications among under 2-month infants were higher than in older patients. DPT vaccination protects children from pertussis infection, and in case of pertussis infection decreases severity. Results indicate that the Ministry of Health should consider adding a booster vaccine for pregnant women in an extended vaccination programme.


Asunto(s)
Tos Ferina , Anciano , Niño , Preescolar , Femenino , Humanos , Programas de Inmunización , Lactante , Vacuna contra la Tos Ferina , Embarazo , Vacunación , Vietnam/epidemiología , Tos Ferina/epidemiología , Tos Ferina/prevención & control
11.
J Neuroeng Rehabil ; 17(1): 162, 2020 12 04.
Artículo en Inglés | MEDLINE | ID: mdl-33276783

RESUMEN

BACKGROUND: Cerebellar ataxia refers to the disturbance in movement resulting from cerebellar dysfunction. It manifests as inaccurate movements with delayed onset and overshoot, especially when movements are repetitive or rhythmic. Identification of ataxia is integral to the diagnosis and assessment of severity, and is important in monitoring progression and improvement. Ataxia is identified and assessed by clinicians observing subjects perform standardised movement tasks that emphasise ataxic movements. Our aim in this paper was to use data recorded from motion sensors worn while subjects performed these tasks, in order to make an objective assessment of ataxia that accurately modelled the clinical assessment. METHODS: Inertial measurement units and a Kinect© system were used to record motion data while control and ataxic subjects performed four instrumented version of upper extremities tests, i.e. finger chase test (FCT), finger tapping test (FTT), finger to nose test (FNT) and dysdiadochokinesia test (DDKT). Kinematic features were extracted from this data and correlated with clinical ratings of severity of ataxia using the Scale for the Assessment and Rating of Ataxia (SARA). These features were refined using Feed Backward feature Elimination (the best performing method of four). Using several different learning models, including Linear Discrimination, Quadratic Discrimination Analysis, Support Vector Machine and K-Nearest Neighbour these extracted features were used to accurately discriminate between ataxics and control subjects. Leave-One-Out cross validation estimated the generalised performance of the diagnostic model as well as the severity predicting regression model. RESULTS: The selected model accurately ([Formula: see text]) predicted the clinical scores for ataxia and correlated well with clinical scores of the severity of ataxia ([Formula: see text], [Formula: see text]). The severity estimation was also considered in a 4-level scale to provide a rating that is familiar to the current clinically-used rating of upper limb impairments. The combination of FCT and FTT performed as well as all four test combined in predicting the presence and severity of ataxia. CONCLUSION: Individual bedside tests can be emulated using features derived from sensors worn while bedside tests of cerebellar ataxia were being performed. Each test emphasises different aspects of stability, timing, accuracy and rhythmicity of movements. Using the current models it is possible to model the clinician in identifying ataxia and assessing severity but also to identify those test which provide the optimum set of data. Trial registration Human Research and Ethics Committee, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia (HREC Reference Number: 11/994H/16).


Asunto(s)
Ataxia Cerebelosa/diagnóstico , Procesamiento de Señales Asistido por Computador , Dispositivos Electrónicos Vestibles , Adulto , Anciano , Australia , Fenómenos Biomecánicos , Ataxia Cerebelosa/fisiopatología , Análisis Discriminante , Femenino , Dedos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Movimiento/fisiología , Extremidad Superior/fisiopatología
12.
Nat Methods ; 12(7): 671-8, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26005811

RESUMEN

The human cerebral cortex develops through an elaborate succession of cellular events that, when disrupted, can lead to neuropsychiatric disease. The ability to reprogram somatic cells into pluripotent cells that can be differentiated in vitro provides a unique opportunity to study normal and abnormal corticogenesis. Here, we present a simple and reproducible 3D culture approach for generating a laminated cerebral cortex-like structure, named human cortical spheroids (hCSs), from pluripotent stem cells. hCSs contain neurons from both deep and superficial cortical layers and map transcriptionally to in vivo fetal development. These neurons are electrophysiologically mature, display spontaneous activity, are surrounded by nonreactive astrocytes and form functional synapses. Experiments in acute hCS slices demonstrate that cortical neurons participate in network activity and produce complex synaptic events. These 3D cultures should allow a detailed interrogation of human cortical development, function and disease, and may prove a versatile platform for generating other neuronal and glial subtypes in vitro.


Asunto(s)
Astrocitos/fisiología , Corteza Cerebral/fisiología , Células Madre Pluripotentes/citología , Astrocitos/citología , Células Cultivadas , Corteza Cerebral/citología , Humanos , Esferoides Celulares , Sinapsis/fisiología
13.
Inorg Chem ; 57(3): 1483-1489, 2018 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-29364659

RESUMEN

DUT-67, an 8-connected zirconium and 2,5-thiophenedicarboxylate-based metal-organic framework (MOF), was postsynthetically functionalized by l-proline via solvent-assisted linker incorporation to obtain a chiral base catalyst. The parent monocarboxylate could be almost completely exchanged by l-proline after 5 days of treatment. The resulting chiral DUT-67 was demonstrated to be a promising heterogeneous catalyst for the asymmetric Michael addition of cyclohexanone to trans-ß-nitrostyrene with excellent yield (up to 96%) and enantioselectivity comparable to that of l-proline in homogeneous reaction (ee of approximately 38%). The Zr-MOF could be reused at least five times without substantial degradation in the crystallinity or catalytic activity. No leaching of catalytically active species into the liquid phase was detected over five cycles.

14.
J Am Chem Soc ; 139(24): 8114-8117, 2017 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-28603973

RESUMEN

Using an iridium catalyst modified by PhanePhos, CF3-allenes react with methanol to form branched products of hydrohydroxymethylation as single regioisomers with excellent levels of enantiomeric enrichment. This hydrogen autotransfer process enables catalytic enantioselective formation of acyclic CF3-bearing all-carbon quaternary stereocenters in the absence of stoichiometric metals or byproducts.


Asunto(s)
Alquenos/química , Carbono/química , Fluorocarburos/química , Iridio/química , Metanol/química , Catálisis , Metilación , Estructura Molecular , Estereoisomerismo
15.
Nature ; 480(7375): 104-8, 2011 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-22101429

RESUMEN

All homeotherms use thermogenesis to maintain their core body temperature, ensuring that cellular functions and physiological processes can continue in cold environments. In the prevailing model of thermogenesis, when the hypothalamus senses cold temperatures it triggers sympathetic discharge, resulting in the release of noradrenaline in brown adipose tissue and white adipose tissue. Acting via the ß(3)-adrenergic receptors, noradrenaline induces lipolysis in white adipocytes, whereas it stimulates the expression of thermogenic genes, such as PPAR-γ coactivator 1a (Ppargc1a), uncoupling protein 1 (Ucp1) and acyl-CoA synthetase long-chain family member 1 (Acsl1), in brown adipocytes. However, the precise nature of all the cell types involved in this efferent loop is not well established. Here we report in mice an unexpected requirement for the interleukin-4 (IL-4)-stimulated program of alternative macrophage activation in adaptive thermogenesis. Exposure to cold temperature rapidly promoted alternative activation of adipose tissue macrophages, which secrete catecholamines to induce thermogenic gene expression in brown adipose tissue and lipolysis in white adipose tissue. Absence of alternatively activated macrophages impaired metabolic adaptations to cold, whereas administration of IL-4 increased thermogenic gene expression, fatty acid mobilization and energy expenditure, all in a macrophage-dependent manner. Thus, we have discovered a role for alternatively activated macrophages in the orchestration of an important mammalian stress response, the response to cold.


Asunto(s)
Catecolaminas/metabolismo , Activación de Macrófagos , Macrófagos/fisiología , Estrés Fisiológico/fisiología , Termogénesis/fisiología , Tejido Adiposo/citología , Tejido Adiposo/metabolismo , Animales , Temperatura Corporal/genética , Células Cultivadas , Frío , Metabolismo Energético , Regulación de la Expresión Génica , Humanos , Interleucina-4 , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Células U937
16.
J Am Chem Soc ; 138(43): 14210-14213, 2016 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-27762549

RESUMEN

The first catalytic enantioselective C-C couplings of methanol (>30 × 106 tons/year) are reported. Insertion of 2-substituted dienes into the methanol C-H bond occurs in a regioselective manner to form all-carbon quaternary centers with excellent levels of enantioselectivity using an iridium-PhanePhos catalyst. Mechanistic studies corroborate a Curtin-Hammett scenario in which methanol dehydrogenation triggers rapid, reversible diene hydrometalation en route to regioisomeric allyliridium-formaldehyde pairs, yet single constitutional isomers are formed.


Asunto(s)
Alquenos/química , Carbono/química , Hidrógeno/química , Iridio/química , Metanol/química , Catálisis , Metilación , Estereoisomerismo
17.
J Am Chem Soc ; 138(16): 5238-41, 2016 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-27079149

RESUMEN

The chiral ruthenium complex formed in situ from (TFA)2Ru(CO)(PPh3)2 and (R)-BINAP is found to catalyze the enantioselective C-C coupling of diverse primary alcohols with the 1,3-enyne, TMSC≡CC(Me)═CH2, to form secondary homopropargyl alcohols bearing gem-dimethyl groups. All reagents for this byproduct-free coupling are inexpensive and commercially available, making this protocol a practical alternative to stoichiometric carbanions in enantioselective carbonyl reverse prenylation.


Asunto(s)
Alquinos/química , Naftalenos/química , Rutenio/química , Alcoholes/química , Catálisis , Hidrogenación , Indicadores y Reactivos/química , Prenilación , Estereoisomerismo
18.
Clin Immunol ; 163: 66-74, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26747737

RESUMEN

Systemic juvenile idiopathic arthritis (sJIA) is characterized by systemic inflammation and arthritis. Monocytes are implicated in sJIA pathogenesis, but their role in disease is unclear. The response of sJIA monocytes to IFN may be dysregulated. We examined intracellular signaling in response to IFN type I (IFNα) and type II (IFNγ) in monocytes during sJIA activity and quiescence, in 2 patient groups. Independent of disease activity, monocytes from Group 1 (collected between 2002 and 2009) showed defective STAT1 phosphorylation downstream of IFNs, and expressed higher transcript levels of SOCS1, an inhibitor of IFN signaling. In the Group 2 (collected between 2011 and 2014), monocytes of patients with recent disease onset were IFNγ hyporesponsive, but in treated, quiescent subjects, monocytes were hyperresponsive to IFNγ. Recent changes in medication in sJIA may alter the IFN hyporesponsiveness. Impaired IFN/pSTAT1 signaling is consistent with skewing of sJIA monocytes away from an M1 phenotype and may contribute to disease pathology.


Asunto(s)
Artritis Juvenil/genética , Interferones/metabolismo , Monocitos/metabolismo , Factor de Transcripción STAT1/metabolismo , Proteínas Supresoras de la Señalización de Citocinas/genética , Adolescente , Artritis Juvenil/inmunología , Artritis Juvenil/metabolismo , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Citometría de Flujo , Regulación de la Expresión Génica , Humanos , Lactante , Interferón gamma/farmacología , Interferones/inmunología , Interferones/farmacología , Masculino , Monocitos/efectos de los fármacos , Monocitos/inmunología , Fosforilación , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Proteína 1 Supresora de la Señalización de Citocinas , Adulto Joven
19.
Proc Natl Acad Sci U S A ; 110(24): 9914-9, 2013 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-23716700

RESUMEN

The liver is a central organ for the synthesis and storage of nutrients, production of serum proteins and hormones, and breakdown of toxins and metabolites. Because the liver is susceptible to toxin- or pathogen-mediated injury, it maintains a remarkable capacity to regenerate by compensatory growth. Specifically, in response to injury, quiescent hepatocytes enter the cell cycle and undergo DNA replication to promote liver regrowth. Despite the elucidation of a number of regenerative factors, the mechanisms by which liver injury triggers hepatocyte proliferation are incompletely understood. We demonstrate here that eosinophils stimulate liver regeneration after partial hepatectomy and toxin-mediated injury. Liver injury results in rapid recruitment of eosinophils, which secrete IL-4 to promote the proliferation of quiescent hepatocytes. Surprisingly, signaling via the IL-4Rα in macrophages, which have been implicated in tissue repair, is dispensable for hepatocyte proliferation and liver regrowth after injury. Instead, IL-4 exerts its proliferative actions via IL-4Rα in hepatocytes. Our findings thus provide a unique mechanism by which eosinophil-derived IL-4 stimulates hepatocyte proliferation in regenerating liver.


Asunto(s)
Eosinófilos/metabolismo , Interleucina-4/metabolismo , Regeneración Hepática/fisiología , Hígado/fisiología , Animales , Ciclo Celular/genética , Ciclo Celular/fisiología , Proliferación Celular , Perfilación de la Expresión Génica , Hepatectomía , Hepatocitos/citología , Hepatocitos/metabolismo , Hepatocitos/fisiología , Immunoblotting , Interleucina-4/genética , Subunidad alfa del Receptor de Interleucina-4/genética , Subunidad alfa del Receptor de Interleucina-4/metabolismo , Hígado/metabolismo , Hígado/cirugía , Regeneración Hepática/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/genética , Transducción de Señal/fisiología
20.
J Am Chem Soc ; 137(9): 3161-4, 2015 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-25734220

RESUMEN

Chiral ruthenium(II) complexes modified by Josiphos ligands catalyze the reaction of alkynes with primary alcohols to form homoallylic alcohols with excellent control of regio-, diastereo-, and enantioselectivity. These processes represent the first examples of enantioselective carbonyl allylation using alkynes as allylmetal equivalents.


Asunto(s)
Alcoholes/química , Alcadienos/química , Alquinos/química , Rutenio/química , Compuestos Alílicos/química , Catálisis , Hidrogenación , Oxidación-Reducción , Estereoisomerismo
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