Evaluation of the Insecticidal Potential of Heterotheca inuloides Acetonic and Methanolic Extracts against Spodoptera frugiperda and Their Ecotoxicological Effect on Poecilia reticulata.

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.

Effect of COVID-19 on quality of life of persons aged >70 years with adult spinal deformity: A cross-sectional case-control study.

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.

Calcium-Dependent Regulation of the Neuronal Glycine Transporter GlyT2 by M2 Muscarinic Acetylcholine Receptors.

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.

The presynaptic glycine transporter GlyT2 is regulated by the Hedgehog pathway in vitro and in vivo.

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.

Structural Determinants of the Neuronal Glycine Transporter 2 for the Selective Inhibitors ALX1393 and ORG25543.

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.

Prehabilitation in patients undergoing pancreaticoduodenectomy: a randomized controlled trial

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

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Prehabilitation in patients undergoing pancreaticoduodenectomy: a randomized controlled trial.

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.

Modification of a Putative Third Sodium Site in the Glycine Transporter GlyT2 Influences the Chloride Dependence of Substrate Transport.

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.

Beneficios Nutricionales, Agroecológicos y Comerciales de las Legumbres / Nutritional, Agro-ecological and Commercial Benefits of Legumes

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.

Resultados preliminares de un programa de cribado del cáncer anal y sus precursores en hombres VIH que tienen sexo con hombres en Vigo-España / Preliminary results of a screening program for anal cancer and its precursors for HIV-infected men who have sex with men in Vigo-Spain

Antecedentes y objetivos: los hombres VIH que tienen sexo con hombres (VIH-HSH) presentan la mayor incidencia de cáncer anal (CA). El estudio tiene como objetivo conocer la prevalencia de la infección anal por virus del papiloma humano de alto riesgo (VPH-AR) y de los hallazgos citológicos e histológicos, así como la implementación de un programa de cribado en el contexto de una ciudad media española, Vigo (España). Método: análisis prospectivo de una cohorte de 264 hombres (VIH-HSH). A los pacientes se les realizó una citología anal y genotipado de VPH-AR para el estudio de la prevalencia de alteraciones citológicas y de la infección VPH-AR. A 209 se les realizó una anoscopia de alta resolución (AAR). Los resultados se relacionaron con variables epidemiológicas, clínicas y analíticas. Resultados: de los 209 pacientes seleccionados, la prevalencia de VPH-AR, alteraciones citológicas e histológicas anales fue de 85,6%, 47,5% y 39,3% respectivamente. La sensibilidad y especificidad para la citología ≥ ASCUS (atipia de células escamosas de significado indeterminado) respecto a las alteraciones histológicas fue de 61% y 85% (OR: 8,7; IC95%: 4,4-17,2), respectivamente. La concordancia observada entre la citología HSIL (lesión escamosa intraepitelial de alto grado) e histología HSIL (AIN-2/3, neoplasia intraepitelial tipo 2 y 3) fue del 64%,(OR: 11,4; IC95%: 3,5-36,7). Un paciente con citología HSIL presentó cáncer escamoso anal prevalente. Conclusiones: la AAR resultó factible y con resultados similares a los de grupos relevantes. Gran prevalencia de la infección anal por VPH-AR y de alteraciones citológicas e histológicas (AU)

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 (AU)

Preliminary results of a screening program for anal cancer and its precursors for HIV-infected men who have sex with men in Vigo-Spain.

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.

Glycine transporters GlyT1 and GlyT2 are differentially modulated by glycogen synthase kinase 3ß.

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.

Differential regulation of the glutamate transporters GLT-1 and GLAST by GSK3ß.

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.

Presynaptic control of glycine transporter 2 (GlyT2) by physical and functional association with plasma membrane Ca2+-ATPase (PMCA) and Na+-Ca2+ exchanger (NCX).

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.

Regulación de la neurotransmisión glicinérgica en procesos de dolor inflamatorio: una nueva vía de acción de la prostaglandina E2 en médula espinal / Regulation of the glycinergic neurotransmission during inflammatory pain: A new pathway in the action of Prostaglandin E2 in the spinal cord

La acción de la glicina como neurotransmisor inhibidor es finalizada por su recaptación del espacio sináptico a través de dos transportadores específicos, GlyT1 (isoforma glial) y GlyT2 (isoforma neuronal). En este trabajo describimos un mecanismo mediante el cual la unión de la prostaglandina E2 (un importante mediador del dolor inflamatorio) a sus receptores EP3 activa la recaptación de glicina llevada a cabo por GlyT2. Esta activación coincide con una disminución de la ubiquitinación del transportador, modificación post-traduccional necesaria para su correcto tráfico intracelular. Una menor ubiquitinación de GlyT2 produce una acumulación del transportador en la superficie neuronal, lo que explica la activación observada. Por tanto, los resultados de este trabajo sugieren que GlyT2 es una interesante diana terapéutica cuya inhibición podría contribuir a la reducción del dolor inflamatorio (AU)

Glycinergic inhibitory neurotransmission is terminated by reuptake through specific transporters, GlyT1 (glial isoform) and GlyT2 (neuronal isoform). In this work we describe that Prostaglandin E2 (PGE2, an important mediator of inflammatory pain) activates GlyT2-mediated recapture of glycine via interaction with the EP3 receptor. Moreover, in these conditions a diminished ubiquitination of GlyT2 is observed. Ubiquitination is an important modification for the correct trafficking of this transporter. We propose that the reduction of ubiquitination leads to accumulate GlyT2 in the neuronal surface, which could explain the PGE2-mediated activation of GlyT2. Therefore, our results suggest that GlyT2 is an interesting therapeutic target and its inhibition could contribute to reduce inflammatory pain (AU)

Na+/K+-ATPase is a new interacting partner for the neuronal glycine transporter GlyT2 that downregulates its expression in vitro and in vivo.

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.