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1.
Plants (Basel) ; 12(20)2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37896019

RESUMEN

For the management of Spodoptera frugiperda, botanical extracts have been used to reduce the environmental impacts of synthetic chemical pesticides. In the present investigation, the insecticidal activity of the acetonic and methanolic extracts of Heterotheca inuloides (Asteraceae) and of the main compound 7-hydroxy-3,4-dihydrocadalene on this pest as well as its ecotoxicological effect on Poecilia reticulata were evaluated. A greater insecticidal response was obtained from the acetonic extracts than from the methanolic extracts, with LC50 values of 730.4 ppm and 711.7 ppm for samples 1 and 2, respectively. Similarly, there was a lethal effect on 50% of the P. reticulata population at low concentrations in the acetonic extract compared to the methanolic extract. The sesquiterpene 7-hydroxy-3,4-dihydrocadalene has greater insecticidal activity by presenting an LC50 of 44.36 ppm; however, it is classified as moderately toxic for guppy fish.

2.
Medicine (Baltimore) ; 101(33): e29954, 2022 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-35984207

RESUMEN

This observational, cross-sectional case-control study evaluates the impact of coronavirus disease 2019 (COVID-19) on health-related quality of life (HRQoL) in elderly persons who have undergone surgery for adult spinal deformity (ASD). On December 31, 2019, the Chinese authorities first reported severe acute respiratory syndrome coronavirus 2, and on March 11, 2020, it was declared a pandemic. The pandemic seems to have had a negative effect on elderly patients who underwent ASD, in terms of functional and psychological quality of life. We selected patients with ASD aged > 70 years who had undergone surgery between 2010 and 2015 and compared them with age- and sex-matched patients who did not have ASD. We recorded sociodemographic variables, type of surgery, levels of spinal fusion, HRQoL (Scoliosis Research Society-22, Short Form 12 Health Survey, EuroQol-5D [EQ-5], Geriatric Depression Scale [Yesavage] [GDS], Modified Frailty Index-11, and Barthel index), fear of visiting a health center, fear of leaving one's house, and adherence to preventive measures. The study population comprised 174 patients (mean [standard deviation] age, 77.3 [5.9] years; 86% women), of whom 87 had undergone surgery for ASD. The incidence of COVID-19 was higher in patients aged > 85 years (P = .041), urban areas (P = .047), and in patients in long-term care (P = .03). Similarly, no differences were observed for the ability to cope with the pandemic (P > .05). Patients who underwent surgery also had a higher risk of depression (GDS, 6.7 [P = .02]), a lower EQ-5 score (P = .001), a higher body mass index (P = .004), greater consumption of drugs (P < .001), especially opiates (P < .001). Patients who underwent surgery constitute a vulnerable population during the COVID-19 pandemic, with poorer quality of life and had a much higher risk of depression. They are also polymedicated and prefrail, adhere well to COVID-19 preventive measures, and do not seem to fear visiting health centers.


Asunto(s)
COVID-19 , Calidad de Vida , Adulto , Anciano , COVID-19/epidemiología , Estudios de Casos y Controles , Estudios Transversales , Femenino , Estudios de Seguimiento , Humanos , Masculino , Pandemias , Estudios Retrospectivos
3.
Neurochem Res ; 47(1): 190-203, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33765249

RESUMEN

The neuronal glycine transporter GlyT2 modulates inhibitory glycinergic neurotransmission and plays a key role in regulating nociceptive signal progression. The cholinergic system acting through muscarinic acetylcholine receptors (mAChRs) also mediates important regulations of nociceptive transmission being the M2 subtype the most abundantly expressed in the spinal cord. Here we studied the effect of M2 mAChRs stimulation on GlyT2 function co-expressed in a heterologous system with negligible levels of muscarinic receptor activity. We found GlyT2 is down-regulated by carbachol in a calcium-dependent manner. Different components involved in cell calcium homeostasis were analysed to establish a role in the mechanism of GlyT2 inhibition. GlyT2 down-regulation by carbachol was increased by thapsigargin and reduced by internal store depletion, although calcium release from endoplasmic reticulum or mitochondria had a minor role on GlyT2 inhibition. Our results are consistent with a GlyT2 sensitivity to intracellular calcium mobilized by M2 mAChRs in the subcortical area of the plasma membrane. A crucial role of the plasma membrane sodium calcium exchanger NCX is proposed.


Asunto(s)
Calcio , Proteínas de Transporte de Glicina en la Membrana Plasmática , Neuronas , Receptor Muscarínico M2 , Animales , Calcio/metabolismo , Proteínas de Transporte de Glicina en la Membrana Plasmática/metabolismo , Neuronas/metabolismo , Ratas , Ratas Wistar , Receptor Muscarínico M2/metabolismo
4.
Commun Biol ; 4(1): 1197, 2021 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-34663888

RESUMEN

The identity of a glycinergic synapse is maintained presynaptically by the activity of a surface glycine transporter, GlyT2, which recaptures glycine back to presynaptic terminals to preserve vesicular glycine content. GlyT2 loss-of-function mutations cause Hyperekplexia, a rare neurological disease in which loss of glycinergic neurotransmission causes generalized stiffness and strong motor alterations. However, the molecular underpinnings controlling GlyT2 activity remain poorly understood. In this work, we identify the Hedgehog pathway as a robust controller of GlyT2 expression and transport activity. Modulating the activation state of the Hedgehog pathway in vitro in rodent primary spinal cord neurons or in vivo in zebrafish embryos induced a selective control in GlyT2 expression, regulating GlyT2 transport activity. Our results indicate that activation of Hedgehog reduces GlyT2 expression by increasing its ubiquitination and degradation. This work describes a new molecular link between the Hedgehog signaling pathway and presynaptic glycine availability.


Asunto(s)
Proteínas de Transporte de Glicina en la Membrana Plasmática/genética , Proteínas de Pez Cebra/genética , Animales , Embrión no Mamífero , Proteínas de Transporte de Glicina en la Membrana Plasmática/metabolismo , Proteínas Hedgehog , Ratas , Ratas Wistar , Transducción de Señal , Pez Cebra , Proteínas de Pez Cebra/metabolismo
5.
ACS Chem Neurosci ; 12(11): 1860-1872, 2021 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-34003005

RESUMEN

The neuronal glycine transporter GlyT2 modulates inhibitory glycinergic neurotransmission by controlling the extracellular concentration of synaptic glycine and the supply of neurotransmitter to the presynaptic terminal. Spinal cord glycinergic neurons present in the dorsal horn diminish their activity in pathological pain conditions and behave as gate keepers of the touch-pain circuitry. The pharmacological blockade of GlyT2 reduces the progression of the painful signal to rostral areas of the central nervous system by increasing glycine extracellular levels, so it has analgesic action. O-[(2-benzyloxyphenyl-3-fluorophenyl)methyl]-l-serine (ALX1393) and N-[[1-(dimethylamino)cyclopentyl]methyl]-3,5-dimethoxy-4-(phenylmethoxy)benzamide (ORG25543) are two selective GlyT2 inhibitors with nanomolar affinity for the transporter and analgesic effects in pain animal models, although with deficiencies which preclude further clinical development. In this report, we performed a comparative ligand docking of ALX1393 and ORG25543 on a validated GlyT2 structural model including all ligand sites constructed by homology with the crystallized dopamine transporter from Drosophila melanogaster. Molecular dynamics simulations and energy analysis of the complex and functional analysis of a series of point mutants permitted to determine the structural determinants of ALX1393 and ORG25543 discrimination by GlyT2. The ligands establish simultaneous contacts with residues present in transmembrane domains 1, 3, 6, and 8 and block the transporter in outward-facing conformation and hence inhibit glycine transport. In addition, differential interactions of ALX1393 with the cation bound at Na1 site and ORG25543 with TM10 define the differential sites of the inhibitors and explain some of their individual features. Structural information about the interactions with GlyT2 may provide useful tools for new drug discovery.


Asunto(s)
Drosophila melanogaster , Proteínas de Transporte de Glicina en la Membrana Plasmática , Animales , Benzamidas/farmacología , Proteínas de Transporte de Glicina en la Membrana Plasmática/genética , Neuronas , Serina/análogos & derivados
6.
Rev Esp Enferm Dig ; 111(8): 603-608, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31232076

RESUMEN

INTRODUCTION: prehabilitation has been proposed as an effective tool to prevent postoperative complications in patients undergoing major abdominal surgery. However, no studies have demonstrated its effectiveness in pancreatic surgical patients. The aim of this study was to assess the impact of prehabilitation on postoperative complications in patients undergoing a pancreaticoduodenectomy (PD). METHODS: this was a randomized controlled trial. Eligible candidates who accepted to participate were randomized to the control (standard care) or intervention (standard care + prehabilitation) group. All patients with pancreatic or periampullary tumors who were candidates for pancreaticoduodenectomy were included. Patients who received neoadjuvant treatment were excluded. Prehabilitation covered three actions: a) nutritional support; b) control of diabetes and exocrine pancreatic insufficiency; and c) physical and respiratory training. The main study outcome was the proportion of patients who suffered postoperative complications. Secondary outcomes included the occurrence of specific complications (pancreatic leak and delayed gastric emptying) and hospital stay. RESULTS: forty patients were included in the analysis. Twenty-two patients were randomized to the control arm and 18, to the intervention group. No statistically significant differences were observed in terms of overall and major complications between the prehabilitation and standard care groups. Pancreatic leak was not statistically different between the groups (11% vs 27%, p = 0.204). However, DGE was significantly lower in the prehabilitation group (5.6% vs 40.9% in the standard care group, p = 0.01). CONCLUSION: prehabilitation did not reduce postoperative complications following pancreaticoduodenectomy. However, a reduction in DGE was observed. Further studies are needed to validate the role and the timing of prehabilitation in high-risk patients.


Asunto(s)
Neoplasias Pancreáticas/cirugía , Pancreaticoduodenectomía , Complicaciones Posoperatorias/prevención & control , Cuidados Preoperatorios/métodos , Adulto , Anciano , Anciano de 80 o más Años , Anastomosis Quirúrgica , Fuga Anastomótica/epidemiología , Ejercicios Respiratorios , Diabetes Mellitus/prevención & control , Ejercicio Físico , Insuficiencia Pancreática Exocrina/prevención & control , Femenino , Humanos , Yeyuno/cirugía , Masculino , Persona de Mediana Edad , Apoyo Nutricional , Complicaciones Posoperatorias/epidemiología , Estómago/cirugía
7.
Front Mol Neurosci ; 11: 347, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30319354

RESUMEN

Neurotransmitter removal from glycine-mediated synapses relies on two sodium-driven high-affinity plasma membrane GlyTs that control neurotransmitter availability. Mostly glial GlyT1 is the main regulator of glycine synaptic levels, whereas neuronal GlyT2 promotes the recycling of synaptic glycine and supplies neurotransmitter for presynaptic vesicle refilling. The GlyTs differ in sodium:glycine symport stoichiometry, showing GlyT1 a 2:1 and GlyT2 a 3:1 sodium:glycine coupling. Sodium binds to the GlyTs at two conserved Na+ sites: Na1 and Na2. The location of GlyT2 Na3 site remains unknown, although Glu650 has been involved in the coordination. Here, we have used comparative MD simulations of a GlyT2 model constructed by homology to the crystalized DAT from Drosophila melanogaster by placing the Na3 ion at two different locations. By combination of in silico and experimental data obtained by biochemical and electrophysiological analysis of GlyTs mutants, we provide evidences suggesting the GlyT2 third sodium ion is held by Glu-250 and Glu-650, within a region with robust allosteric properties involved in cation-specific sensitivity. Substitution of Glu650 in GlyT2 by the corresponding methionine in GlyT1 reduced the charge-to-flux ratio to the level of GlyT1 without producing transport uncoupling. Chloride dependence of glycine transport was almost abolished in this GlyT2 mutant but simultaneous substitution of Glu250 and Glu650 by neutral amino acids rescued chloride sensitivity, suggesting that protonation/deprotonation of Glu250 substitutes chloride function. The differential behavior of equivalent GlyT1 mutations sustains a GlyT2-specific allosteric coupling between the putative Na3 site and the chloride site.

8.
Rev. chil. nutr ; 45(supl.1): 8-13, 2018. tab
Artículo en Español | LILACS | ID: biblio-899862

RESUMEN

RESUMEN Las legumbres juegan un rol fundamental en la seguridad alimentaria y nutricional (SAN) de millones de personas en todo el mundo. Se estima que alrededor de 50 millones de agricultores familiares las producen, consumen y comercializan (a baja escala) de forma tradicional. La Asamblea General de las Naciones Unidas, en su 68° sesión en 2013, reconoció su importancia al declarar 2016 como el Año Internacional de las Legumbres (AIL2016). La Organización de las Naciones Unidas para la Alimentación y la Agricultura (FAO) fue designada para llevar a cabo las actividades de promoción del Año, en colaboración con gobiernos, organizaciones no gubernamentales, academia y otros actores relevantes interesados. El Año tiene como objetivo aumentar la conciencia pública sobre los beneficios nutricionales y para la salud que tienen las legumbres como parte de los sistemas alimentarios sostenibles dirigidos a mejorar la SAN; revalorizar su aporte de proteínas; promover su producción global; resaltar sus cualidades para mejorar la rotación de cultivos y adaptación al cambio climático; y dar respuesta a los retos para su comercialización.


ABSTRACT Legumes play a key role in food and nutritional security (FNS) for millions of people around the world, with an estimated 50 million family farmers producing, consuming and marketing (low-scale) legumes in a traditional way. At its 68th session in 2013, the General Assembly of the United Nations declared 2016 as the International Year of Legumes. The Food and Agriculture Organization of the United Nations was designated to facilitate the implementation of the legume year in collaboration with governments, non-governmental organizations, academia and other stakeholders. The purpose of the year of the legume was to increase public awareness of the nutritional and health benefits that legumes have, as part of a sustainable food systems, focused on improving FNS; revaluing legume-based proteins; promoting global production; highlighting its quality to encourage better crop rotation and adaptation to climate change; and responding to the markets challenges.


Asunto(s)
Humanos , Producción de Alimentos , Desnutrición , Fabaceae , Dieta Saludable
9.
Rev Esp Enferm Dig ; 109(4): 242-249, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28229612

RESUMEN

BACKGROUND: Men who have sex with men (MSM) infected with human immunodeficiency virus (HIV) have the highest risk of developing anal cancer (AC). The objective of this study was to describe our screening implementation program in this population, and report the prevalence of human papillomavirus (HPV) anal infection, and cytological and histological findings in a Spanish medium-size community (Vigo, Spain). METHOD: Prospective cohort analysis of 240 HIV-infected MSM. Cellular anal sample and high risk HPV (HR-HPV)-tests were performed to study cytological changes and HPV genotyping. High resolution anoscopy (HRA) was performed in 209 patients. Results were analyzed with respect to epidemiological, clinical and analytical factors. RESULTS: Of 209 patients selected for HRA, the prevalence of HR-HPV anal infection, cytological and histological alterations was 85.6%, 47.5%, and 39.8%, respectively. Sensitivity and specificity for ≥ ASCUS (atypia of squamous cells of undetermined significance) cytology in relation to histological alterations were 61% and 85%, (OR: 8.7; IC 95%: 4.4-17.2), respectively. Observed concordance between high-grade squamous intraepithelial lesion (HSIL) cytology and HSIL anal intraepithelial neoplasia types 2 and 3 (AIN-2/3) histology was 64% (OR: 11.4; IC 95%: 3.6-36.7). One patient with HSIL cytology presented a prevalent anal squamous carcinoma. CONCLUSIONS: HRA was feasible with similar results to relevant groups. There was a high prevalence of anal HR-HPV infection, and cytological and histological alterations.


Asunto(s)
Neoplasias del Ano/diagnóstico , Infecciones por VIH/complicaciones , Infecciones por Papillomavirus/diagnóstico , Adulto , Neoplasias del Ano/epidemiología , Estudios de Cohortes , Estudios Transversales , Infecciones por VIH/epidemiología , Homosexualidad Masculina , Humanos , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Infecciones por Papillomavirus/epidemiología , Lesiones Precancerosas/diagnóstico , Prevalencia , Estudios Prospectivos , Factores de Riesgo , Conducta Sexual
13.
Neuropharmacology ; 89: 245-54, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25301276

RESUMEN

Inhibitory glycinergic neurotransmission is terminated by the specific glycine transporters GlyT1 and GlyT2 which actively reuptake glycine from the synaptic cleft. GlyT1 is associated with both glycinergic and glutamatergic pathways, and is the main regulator of the glycine levels in the synapses. GlyT2 is the main supplier of glycine for vesicle refilling, a process that is vital to preserve the quantal glycine content in synaptic vesicles. Therefore, to control glycinergic neurotransmission efficiently, GlyT1 and GlyT2 activity must be regulated by diverse neuronal and glial signaling pathways. In this work, we have investigated the possible functional modulation of GlyT1 and GlyT2 by glycogen synthase kinase 3 (GSK3ß). This kinase is involved in mood stabilization, neurodegeneration and plasticity at excitatory and inhibitory synapses. The co-expression of GSK3ß with GlyT1 or GlyT2 in COS-7 cells and Xenopus laevis oocytes, leads to inhibition and stimulation of GlyT1 and GlyT2 activities, respectively, with a decrease of GlyT1, and an increase in GlyT2 levels at the plasma membrane. The specificity of these changes is supported by the antagonism exerted by a catalytically inactive form of the kinase and through inhibitors of GSK3ß such as lithium chloride and TDZD-8. GSK3ß also increases the incorporation of 32Pi into GlyT1 and decreases that of GlyT2. The pharmacological inhibition of the endogenous GSK3ß in neuron cultures of brainstem and spinal cord leads to an opposite modulation of GlyT1 and GlyT2.Our results suggest that GSK3ß is important for stabilizing and/or controlling the expression of functional GlyTs on the neural cell surface.


Asunto(s)
Proteínas de Transporte de Glicina en la Membrana Plasmática/metabolismo , Glucógeno Sintasa Quinasa 3/metabolismo , Neuronas/metabolismo , Animales , Transporte Biológico , Tronco Encefálico/citología , Células COS , Células Cultivadas , Chlorocebus aethiops , Inhibidores Enzimáticos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/genética , Glicina/metabolismo , Glicina/farmacología , Proteínas de Transporte de Glicina en la Membrana Plasmática/genética , Glucógeno Sintasa Quinasa 3/genética , Glucógeno Sintasa Quinasa 3 beta , Cloruro de Litio/farmacología , Neuronas/efectos de los fármacos , Oocitos , Ratas , Ratas Wistar , Médula Espinal/citología , Tritio/metabolismo , Xenopus laevis
14.
Neurochem Int ; 79: 33-43, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25454285

RESUMEN

The glutamate transporters GLAST and GLT-1 are mainly expressed in glial cells and regulate glutamate levels in the synapses. GLAST and GLT-1 are the targets of several signaling pathways. In this study we explore the possible functional interaction between these transporters and GSK3ß. This kinase is involved in multiple cellular processes including neuronal development and synaptic plasticity. To evaluate whether GLT-1 and GLAST were regulated by GSK3ß, we coexpressed these proteins in heterologous expression systems. In both COS-7 cells and Xenopus laevis oocytes, GSK3ß stimulated the activity of GLT-1 and reduced that of GLAST. These effects were associated with corresponding changes in the amounts of GLT-1 or GLAST in the plasma membrane. These effects were suppressed by inhibitors of GSK3ß or a catalytically inactive form of the kinase. GSK3ß also decreases the incorporation of (32)Pi into GLT-1 and increases GLAST phosphorylation. Pharmacological inhibition of endogenous GSK3ß in primary cultures of rat brain cortex also leads to a differential modulation of GLT-1 and GLAST. Our results suggest that constitutively active GSK3ß is important in controlling the expression of functional glutamate transporters on the plasma membrane. This regulation might be relevant in physiological and pathological conditions in which glutamate transporters and GSK3ß signaling are involved.


Asunto(s)
Transportador 1 de Aminoácidos Excitadores/biosíntesis , Transportador 2 de Aminoácidos Excitadores/biosíntesis , Glucógeno Sintasa Quinasa 3/metabolismo , Animales , Biotinilación , Células COS , Chlorocebus aethiops , Transportador 1 de Aminoácidos Excitadores/genética , Transportador 2 de Aminoácidos Excitadores/genética , Regulación de la Expresión Génica/fisiología , Ácido Glutámico/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Humanos , Masculino , Oocitos/metabolismo , Técnicas de Placa-Clamp , Cultivo Primario de Células , Ratas , Xenopus
15.
J Biol Chem ; 289(49): 34308-24, 2014 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-25315779

RESUMEN

Fast inhibitory glycinergic transmission occurs in spinal cord, brainstem, and retina to modulate the processing of motor and sensory information. After synaptic vesicle fusion, glycine is recovered back to the presynaptic terminal by the neuronal glycine transporter 2 (GlyT2) to maintain quantal glycine content in synaptic vesicles. The loss of presynaptic GlyT2 drastically impairs the refilling of glycinergic synaptic vesicles and severely disrupts neurotransmission. Indeed, mutations in the gene encoding GlyT2 are the main presynaptic cause of hyperekplexia in humans. Here, we show a novel endogenous regulatory mechanism that can modulate GlyT2 activity based on a compartmentalized interaction between GlyT2, neuronal plasma membrane Ca(2+)-ATPase (PMCA) isoforms 2 and 3, and Na(+)/Ca(2+)-exchanger 1 (NCX1). This GlyT2·PMCA2,3·NCX1 complex is found in lipid raft subdomains where GlyT2 has been previously found to be fully active. We show that endogenous PMCA and NCX activities are necessary for GlyT2 activity and that this modulation depends on lipid raft integrity. Besides, we propose a model in which GlyT2·PMCA2-3·NCX complex would help Na(+)/K(+)-ATPase in controlling local Na(+) increases derived from GlyT2 activity after neurotransmitter release.


Asunto(s)
Proteínas de Transporte de Glicina en la Membrana Plasmática/metabolismo , ATPasas Transportadoras de Calcio de la Membrana Plasmática/metabolismo , Células Receptoras Sensoriales/metabolismo , Intercambiador de Sodio-Calcio/metabolismo , Animales , Tronco Encefálico/citología , Tronco Encefálico/efectos de los fármacos , Tronco Encefálico/metabolismo , Regulación de la Expresión Génica , Proteínas de Transporte de Glicina en la Membrana Plasmática/genética , Péptidos y Proteínas de Señalización Intercelular , Masculino , Microdominios de Membrana/química , Microdominios de Membrana/efectos de los fármacos , Microdominios de Membrana/metabolismo , Péptidos/farmacología , ATPasas Transportadoras de Calcio de la Membrana Plasmática/antagonistas & inhibidores , ATPasas Transportadoras de Calcio de la Membrana Plasmática/genética , Terminales Presinápticos/efectos de los fármacos , Cultivo Primario de Células , Unión Proteica , Ratas , Ratas Wistar , Células Receptoras Sensoriales/citología , Células Receptoras Sensoriales/efectos de los fármacos , Intercambiador de Sodio-Calcio/antagonistas & inhibidores , Intercambiador de Sodio-Calcio/genética , Médula Espinal/citología , Médula Espinal/efectos de los fármacos , Médula Espinal/metabolismo , Transmisión Sináptica , Tiourea/análogos & derivados , Tiourea/farmacología , beta-Ciclodextrinas/farmacología
17.
J Neurosci ; 33(35): 14269-81, 2013 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-23986260

RESUMEN

The neuronal glycine transporter GlyT2 plays a fundamental role in the glycinergic neurotransmission by recycling the neurotransmitter to the presynaptic terminal. GlyT2 is the main supplier of glycine for vesicle refilling, a process that is absolutely necessary to preserve quantal glycine content in synaptic vesicles. Alterations in GlyT2 activity modify glycinergic neurotransmission and may underlie several neuromuscular disorders, such as hyperekplexia, myoclonus, dystonia, and epilepsy. Indeed, mutations in the gene encoding GlyT2 are the main presynaptic cause of hyperekplexia in humans and produce congenital muscular dystonia type 2 (CMD2) in Belgian Blue cattle. GlyT2 function is strictly coupled to the sodium electrochemical gradient actively generated by the Na+/K+-ATPase (NKA). GlyT2 cotransports 3Na+/Cl-/glycine generating large rises of Na+ inside the presynaptic terminal that must be efficiently reduced by the NKA to preserve Na+ homeostasis. In this work, we have used high-throughput mass spectrometry to identify proteins interacting with GlyT2 in the CNS. NKA was detected as a putative candidate and through reciprocal coimmunoprecipitations and immunocytochemistry analyses the association between GlyT2 and NKA was confirmed. NKA mainly interacts with the raft-associated active pool of GlyT2, and low and high levels of the specific NKA ligand ouabain modulate the endocytosis and total expression of GlyT2 in neurons. The ouabain-mediated downregulation of GlyT2 also occurs in vivo in two different systems: zebrafish embryos and adult rats, indicating that this NKA-mediated regulatory mechanism is evolutionarily conserved and may play a relevant role in the physiological control of inhibitory glycinergic neurotransmission.


Asunto(s)
Regulación hacia Abajo , Proteínas de Transporte de Glicina en la Membrana Plasmática/metabolismo , Neuronas/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Proteínas de Pez Cebra/metabolismo , Animales , Tronco Encefálico/citología , Endocitosis , Regulación del Desarrollo de la Expresión Génica , Proteínas de Transporte de Glicina en la Membrana Plasmática/genética , Homeostasis , Masculino , Microdominios de Membrana/metabolismo , Ouabaína/farmacología , Ratas , Ratas Wistar , Sodio/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , Médula Espinal/citología , Pez Cebra , Proteínas de Pez Cebra/genética
18.
PLoS One ; 8(3): e58863, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23484054

RESUMEN

Inhibitory glycinergic neurotransmission is terminated by sodium and chloride-dependent plasma membrane glycine transporters (GlyTs). The mainly glial glycine transporter GlyT1 is primarily responsible for the completion of inhibitory neurotransmission and the neuronal glycine transporter GlyT2 mediates the reuptake of the neurotransmitter that is used to refill synaptic vesicles in the terminal, a fundamental role in the physiology and pathology of glycinergic neurotransmission. Indeed, inhibitory glycinergic neurotransmission is modulated by the exocytosis and endocytosis of GlyT2. We previously reported that constitutive and Protein Kinase C (PKC)-regulated endocytosis of GlyT2 is mediated by clathrin and that PKC accelerates GlyT2 endocytosis by increasing its ubiquitination. However, the role of ubiquitination in the constitutive endocytosis and turnover of this protein remains unexplored. Here, we show that ubiquitination of a C-terminus four lysine cluster of GlyT2 is required for constitutive endocytosis, sorting into the slow recycling pathway and turnover of the transporter. Ubiquitination negatively modulates the turnover of GlyT2, such that increased ubiquitination driven by PKC activation accelerates transporter degradation rate shortening its half-life while decreased ubiquitination increases transporter stability. Finally, ubiquitination of GlyT2 in neurons is highly responsive to the free pool of ubiquitin, suggesting that the deubiquitinating enzyme (DUB) ubiquitin C-terminal hydrolase-L1 (UCHL1), as the major regulator of neuronal ubiquitin homeostasis, indirectly modulates the turnover of GlyT2. Our results contribute to the elucidation of the mechanisms underlying the dynamic trafficking of this important neuronal protein which has pathological relevance since mutations in the GlyT2 gene (SLC6A5) are the second most common cause of human hyperekplexia.


Asunto(s)
Endocitosis/fisiología , Proteínas de Transporte de Glicina en la Membrana Plasmática/metabolismo , Lisina/metabolismo , Transmisión Sináptica/fisiología , Animales , Perros , Humanos , Inmunohistoquímica , Inmunoprecipitación , Células de Riñón Canino Madin Darby , Masculino , Microscopía Confocal , Microscopía Fluorescente , Ratas , Ratas Wistar , Ubiquitina Tiolesterasa/metabolismo , Ubiquitinación
19.
Coluna/Columna ; 12(4): 312-314, 2013. ilus
Artículo en Español | LILACS | ID: lil-699037

RESUMEN

OBJETIVO: Observar el comportamiento del tornillo expansivo en pacientes con mala calidad ósea, su seguridad, técnica, manejo y complicaciones: porcentaje de aflojamiento, roturas, "pull-out" y pseudartrosis. MÉTODOS: Realizamos estudio prospectivo multicéntrico analizando factores de riesgo del paciente, VAS, tiempo quirúrgico, pérdida de sangre, emplazamiento de tornillos y complicaciones debidas al implante a la alta y a los 3, 12 y 24 meses. RESULTADOS: El 99% de los pacientes no tuvieron ninguna complicación permanente relacionada con el implante; sólo hubo un caso de radiculopatía no resuelta. En el 95% de los implantes, los tornillos se colocaron sin complicaciones; en el 5% aparecieron complicaciones relacionadas con la mala colocación o expansión del tornillo, resueltas en acto quirúrgico. Tiempo quirúrgico promedio por nivel, 56 min.; tiempo promedio por intervención, 2 horas 35 min. Sangramiento promedio por nivel intervenido, 211cc. Hemos tenido tres casos de "pull-out". El VAS evolucionó favorablemente de forma significativa, con reducciones promedio mayores a cuatro puntos. El estudio continuará hasta los cinco años, siendo estos los resultados preliminares. CONCLUSIONES: Este tipo de tornillos expansivos aportan un nuevo sistema de anclaje para pacientes con mala calidad ósea; son seguros y eficaces, ofrecen rapidez en su colocación, una menor exposición a los RXy, en caso de retirada del tornillo, dejan el camino libre para una nueva cirugía.


OBJETIVO: Observar o comportamento do parafuso expansivo em pacientes com má qualidade óssea, sua segurança, a técnica, conduta e complicações: porcentagem de afrouxamento, quebras, "pull-out" e pseudoartrose. MÉTODOS: Estudo prospectivo multicêntrico analisando fatores de risco do paciente, VAS, tempo cirúrgico, perda de sangue, localização dos parafusos e complicações devido ao implante na alta e aos 3, 12 e 24 meses. RESULTADOS: 99% dos pacientes não tiveram nenhuma complicação permanente relacionada com o implante; apenas um caso de radiculopatia não se resolveu. Em 95% dos implantes, os parafusos foram colocados sem complicações; em 5% houve complicações relacionadas com a má colocação ou expansão do parafuso, que foram resolvidas com cirurgia. Tempo médio de cirurgia por nível, 56 min.; tempo médio por intervenção, 2 horas e 35 min. Sangramento médio por nível que recebeu intervenção, 211 cc. Ocorreram três casos de "pull-out". A VAS evoluiu favoravelmente e de forma significante, con reduções médias maiores que quatro pontos. O estudo continuará até os cinco anos, sendo que estes são os resultados preliminares. CONCLUSÕES: Esse tipo de parafuso expansivo é um novo sistema de ancoragem para pacientes com má qualidade óssea; são seguros e eficazes, rápidos para colocar, proporcionam menos exposição aos RX e, em caso de retirada do parafuso, deixam o caminho livre para uma nova cirurgia.


OBJECTIVE: To observe the behavior of the expansive screw in patients with poor bone quality, its safety, the technique, conduct and complications: percentage of loosening, breaks, pull-outs and pseudoarthrosis. METHODS: Prospective multicenter study analyzing the patient’s risk factors, VAS, surgery time, blood loss, location of the screws and complications due to the implant at the time of discharge, and at 3, 12 and 24 months. RESULTS: 99% of the patients did not have any permanent complications related to the implant; there was only one case of unresolved radiculopathy. In 95% of the implants, the screws were placed without complications; in 5% percent of cases there were complications related to poor placement or expansion of the screw, which were resolved with the surgery. Mean intervention time per level: 56 minutes; average intervention time, 2 hours and 35 min. Average bleeding per level that received intervention, 211cc. There were three cases of "pull-out". VAS evolved favorably and significantly, with average reduction greater than four points. The study will continue until age five, these being the preliminary results. CONCLUSIONS: This type of expansive screw provides a new anchoring system for patients with poor bone quality; it is safe and effective, easy to insert, and provides less exposure to X-ray, and in case of removal of the screw, it leaves the way free for a new surgery.


Asunto(s)
Humanos , Tornillos Óseos , Osteoporosis , Artrodesis , Columna Vertebral/cirugía
20.
J Biol Chem ; 287(34): 28986-9002, 2012 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-22753417

RESUMEN

Hyperekplexia or startle disease is characterized by an exaggerated startle response, evoked by tactile or auditory stimuli, producing hypertonia and apnea episodes. Although rare, this orphan disorder can have serious consequences, including sudden infant death. Dominant and recessive mutations in the human glycine receptor (GlyR) α1 gene (GLRA1) are the major cause of this disorder. However, recessive mutations in the presynaptic Na(+)/Cl(-)-dependent glycine transporter GlyT2 gene (SLC6A5) are rapidly emerging as a second major cause of startle disease. In this study, systematic DNA sequencing of SLC6A5 revealed a new dominant GlyT2 mutation: pY705C (c.2114A→G) in transmembrane domain 11, in eight individuals from Spain and the United Kingdom. Curiously, individuals harboring this mutation show significant variation in clinical presentation. In addition to classical hyperekplexia symptoms, some individuals had abnormal respiration, facial dysmorphism, delayed motor development, or intellectual disability. We functionally characterized this mutation using molecular modeling, electrophysiology, [(3)H]glycine transport, cell surface expression, and cysteine labeling assays. We found that the introduced cysteine interacts with the cysteine pair Cys-311-Cys-320 in the second external loop of GlyT2. This interaction impairs transporter maturation through the secretory pathway, reduces surface expression, and inhibits transport function. Additionally, Y705C presents altered H(+) and Zn(2+) dependence of glycine transport that may affect the function of glycinergic neurotransmission in vivo.


Asunto(s)
Genes Dominantes , Enfermedades Genéticas Congénitas , Proteínas de Transporte de Glicina en la Membrana Plasmática , Mutación Missense , Proteínas del Tejido Nervioso , Enfermedades del Sistema Nervioso , Sustitución de Aminoácidos , Animales , Femenino , Enfermedades Genéticas Congénitas/genética , Enfermedades Genéticas Congénitas/metabolismo , Glicina/genética , Glicina/metabolismo , Proteínas de Transporte de Glicina en la Membrana Plasmática/genética , Proteínas de Transporte de Glicina en la Membrana Plasmática/metabolismo , Humanos , Transporte Iónico/genética , Masculino , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Enfermedades del Sistema Nervioso/genética , Enfermedades del Sistema Nervioso/metabolismo , Terminales Presinápticos , Transporte de Proteínas/genética , España , Reino Unido
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