Multistability in Macrophage Activation Pathways and Metabolic Implications.

Macrophages are innate immune cells with a dynamic range of reversible activation states including the classical pro-inflammatory (M1) and alternative anti-inflammatory (M2) states. Deciphering how macrophages regulate their transition from one state to the other is key for a deeper understanding of inflammatory diseases and relevant therapies. Common regulatory motifs reported for macrophage transitions, such as positive or double-negative feedback loops, exhibit a switchlike behavior, suggesting the bistability of the system. In this review, we explore the evidence for multistability (including bistability) in macrophage activation pathways at four molecular levels. First, a decision-making module in signal transduction includes mutual inhibitory interactions between M1 (STAT1, NF-KB/p50-p65) and M2 (STAT3, NF-KB/p50-p50) signaling pathways. Second, a switchlike behavior at the gene expression level includes complex network motifs of transcription factors and miRNAs. Third, these changes impact metabolic gene expression, leading to switches in energy production, NADPH and ROS production, TCA cycle functionality, biosynthesis, and nitrogen metabolism. Fourth, metabolic changes are monitored by metabolic sensors coupled to AMPK and mTOR activity to provide stability by maintaining signals promoting M1 or M2 activation. In conclusion, we identify bistability hubs as promising therapeutic targets for reverting or blocking macrophage transitions through modulation of the metabolic environment.

[Spanish patients with central hypoventilation syndrome included in the European Registry. The 2015 data]. / Pacientes españoles con síndrome de hipoventilación central incluidos en el Registro europeo. Datos del 2015.

INTRODUCTION: Congenital Central Hypoventilation Syndrome (CCHS) is a very rare genetic disease. In 2012 the European Central Hypoventilation Syndrome (EuCHS) Consortium created an online patient registry in order to improve care. AIM: To determine the characteristics and outcomes of Spanish patients with CCHS, and detect clinical areas for improvement. MATERIALS AND METHOD: An assessment was made on the data from Spanish patients in the European Registry, updated on December 2015. RESULTS: The Registry contained 38 patients, born between 1987 and 2013, in 18 hospitals. Thirteen (34.2%) were older than 18 years. Three patients had died. Genetic analysis identified PHOX2B mutations in 32 (86.5%) out of 37 patients assessed. The 20/25, 20/26 and 20/27 polyalanine repeat mutations (PARMs) represented 84.3% of all mutations. Longer PARMs had more, as well as more severe, autonomic dysfunctions. Eye diseases were present in 47%, with 16% having Hirschsprung disease, 13% with hypoglycaemia, and 5% with tumours. Thirty patients (79%) required ventilation from the neonatal period onwards, and 8 (21%) later on in life (late onset/presentation). Eight children (21%) were using mask ventilation at the first home discharge. Five of them were infants with neonatal onset, two of them, both having a severe mutation, were switched to tracheostomy after cardiorespiratory arrest at home. Approximately one-third (34.3%) of patients were de-cannulated and switched to mask ventilation at a mean age of 13.7 years. Educational reinforcement was required in 29.4% of children attending school. CONCLUSION: The implementation of the EuCHS Registry in Spain has identified some relevant issues for optimising healthcare, such as the importance of genetic study for diagnosis and assessment of severity, the high frequency of eye disease and educational reinforcement, as well as some limitations in ventilatory techniques.

Purinergic P2X7 receptors mediate cell death in mouse cerebellar astrocytes in culture.

The brain distribution and functional role of glial P2X7 receptors are broader and more complex than initially anticipated. We characterized P2X7 receptors from cerebellar astrocytes at the molecular, immunocytochemical, biophysical, and cell physiologic levels. Mouse cerebellar astrocytes in culture express mRNA coding for P2X7 receptors, which is translated into P2X7 receptor protein as proven by Western blot analysis and immunocytochemistry. Fura-2 imaging showed cytosolic calcium responses to ATP and the synthetic analog 3'-O-(4-benzoyl)benzoyl-ATP (BzATP) exhibited two components, namely an initial transient and metabotropic component followed by a sustained one that depended on extracellular calcium. This latter component, which was absent in astrocytes from P2X7 receptor knockout mice (P2X7 KO), was modulated by extracellular Mg(2+), and was sensitive to Brilliant Blue G (BBG) and 3-(5-(2,3-dichlorophenyl)-1H-tetrazol-1-yl)methyl pyridine (A438079) antagonism. BzATP also elicited inwardly directed nondesensitizing whole-cell ionic currents that were reduced by extracellular Mg(2+) and P2X7 antagonists (BBG and calmidazolium). In contrast to that previously reported in rat cerebellar astrocytes, sustained BzATP application induced a gradual increase in membrane permeability to large cations, such as N-methyl-d-glucamine and 4-[3-methyl-2(3H)-benzoxazolylidene)-methyl]-1-[3-(triethylammonio)propyl]diiodide, which ultimately led to the death of mouse astrocytes. Cerebellar astrocyte cell death was prevented by BBG but not by calmidazolium, removal of extracellular calcium, or treatment with the caspase-3 inhibitor, benzyloxycarbonyl-Asp(OMe)-Glu(OMe)-Val-Asp(OMe)-fluoromethylketone, thus suggesting a necrotic-type mechanism of cell death. Since this cellular response was not observed in astrocytes from P2X7 KO mice, this study suggests that stimulation of P2X7 receptor may convey a cell death signal to cerebellar astrocytes in a species-specific manner.

Diversidad y universalidad como respuesta a pie diabético en paciente paquistaní con diabetes mellitus tipo 2 desde Atención Primaria / Diversity and universality in response to patient diabetic foot pakistani with type 2 diabetes mellitus from primarycare

Siguiendo las enseñanzas de Madeleine Leininger sobre los conceptos de su modelo transcultural, buscamos una respuesta en el entorno de la Atención Primaria al caso que nos ocupa de una lesión ulcerosa en pie izquierdo, de etiología desconocida, en paciente paquistaní con diabetes mellitus tipo 2. Hallando la respuesta mediante la adaptación de similitudes de riesgo en el entorno de esta enfermedad, comunes en todas las culturas, y cuyas diferencias estriban en la localización de la úlcera y su factor desencadenante. Anómalas en nuestra cultura al estar relacionada con sus prácticas culturales (AU)

Following the teachings of Madeleine Leininger on transcultural concepts in their model, we seek an answer in the primary care environment to the present case of left standing ulcerative lesion of unknown etiology in Pakistani patients with type 2 Diabetes Mellitus. Finding the answer by adapting similarities in the environment risk to this disease, common in all cultures and whose differences lie in the location of the ulcer and its trigger. Abnormal in our culture to be related to their cultural practices (AU)

Interacción entre receptores de glutamato y receptores de nucleótidos en neuronas granulares de cerebelo en cultivo / Cross-talk between glutamate and nucleotide receptors in cerebellar granule neurons in culture

ATP elicits Ca2+ transients in cultured cerebellar granule neuronsacting through specific ionotropic (P2X) and metabotropic (P2Y)purinergic receptors. In these neurons, application of L-Glutamate(L-Glu) immediately before ATP induced a prolonged reductionof ATP-mediated responses that remains at least 5 minutes afterL-Glu wash out. alpha-amino-3-hydro-5-methyl-4-isoxazolpropionicacid (AMPA), N-methyl-D-aspartate (NMDA) and 3,5-dihydroxyphenyl-glycine (DHPG), selective agonists of ionotropic non-NMDA,NMDA and Group I metabotropic glutamate receptors respectively,mimicked Glu-induced attenuating effects. The activity of calciumcalmodulindependent protein kinase II (CaMKII) seems to beinvolved, at least at long term, because inhibitors of CaMKII, 1-[N,Obis(5-isoquinolinesulfonyl)-N-methyl-L-(KN-62) and N-[2-[[[3-(4'-chlorophenyl)-2-propenyl]methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4'-methoxybenzenesulfonamide(KN-93), abolished the inhibitory effect of L-Glu on ATP-mediatedresponses. However, it is likely that other protein kinases could beinvolved in the cross-talk process between both groups of receptorsat short term. Therefore, these results demonstrate that the activationof glutamate receptors is able to modulate nucleotide responses incerebellar granule neurons(AU)

Interacción entre receptores de glutamato y receptores denucleótidos en neuronas granulares de cerebelo en cultivoEl ATP induce un incremento de Ca2+ en neuronas granulares decerebelo en cultivo actuando a través de receptores purinérgicos específicosionótropicos (P2X) y metabotrópicos (P2Y). En estas neuronas,la aplicación de L-Glutamato (L-Glu) inmediatamente antes del ATPinduce una prolongada disminución de las respuestas mediadas porATP que se mantiene al menos durante cinco minutos tras el lavadodel L-Glu. Los agonistas selectivos de los receptores ionotrópicosde glutamato no-NMDA, NMDA y del Grupo I, el ácido alfa-amino-3-hidro-5-metil-4-isoxazolpropiónico (AMPA), el N-metil-D-aspartato(NMDA) y el 3,5-dihidroxifenil-glicina (DHPG), respectivamente, mimetizanlos efectos atenuantes inducidos por el glutamato. La actividadde la proteína calcio-calmodulina quinasa II (CaMKII) pareceestar implicada en este proceso, al menos a largo plazo, puesto quelos inhibidores de la CaMKII, 1-[N,O-bis(5-isoquinolinesulfonil)-Nmetil-L-tirosil]-4fenilpiperazine (KN-62) y N-[2-[[[3-(4'-clorofenil)-2-propenil]metilamino]metil]fenil]-N-(2-hidroxietil)-4'-metoxibenzenosulfonamida(KN-93), revierten el efecto inhibitorio del L-Glu sobrelas respuestas mediadas por ATP. Sin embargo, es probable que puedanestar implicadas otras proteín quinasas en los procesos de interacciónentre ambos grupos de receptores a corto plazo. Por lo tanto,estos resultados demuestran que la activación de los receptores deglutamato son capaces de modular las respuestas a nucleótidos enneuronas granulares de cerebelo(AU)

Axodendritic fibres of mouse cerebellar granule neurons exhibit a diversity of functional P2X receptors.

Distribution and functional expression of P2X receptors were analyzed in mouse cerebellum axodendritic fibres, using different experimental approaches such as RT-PCR, western blot, immunochemistry, microfluorimetric experiments and exocytotic studies. RT-PCR and western blot demonstrated the presence of P2X1-4,7 subunits in both whole cerebellum and mouse cerebellar granule cultured neurons. Immunochemistry analysis of tissular and cellular location of P2X1-4,7 receptors confirmed their presence and unequal distribution between somas and axodendritic prolongations. Microfluorimetric experiments using a variety of modulators of the P2X subunits revealed the presence of different functional P2X receptors in the axodendritic fibres. The use of the synthetic agonist alpha,beta-meATP and the antagonist Ip(5)I revealed the activation of functional P2X1 and P2X3 receptors. Responses mediated by P2X1 subunits were also confirmed by using ZnSO(4). Activation of functional P2X4 receptors is observed when stimulated in the presence of ivermectin. Exocytotic studies confirmed the role of most P2X subunits in the activation of neurotransmitter release in axodendritic fibres from mouse cerebellar granule neurons.

Physiological role of extracellular nucleotides at the central nervous system: signalling through P2X and P2Y receptors

En los últimos años los receptores de nucleótidos, receptores ionotrópicosP2X1-7 y metabotrópicos P2Y1, 2, 4, 6, 11, 12, 13, 14, han adquirido una importancia excepcionaldebido a su localización estratégica en órganos y tejidos, a su gran variedadjunto con la complejidad de vías de señalización a las que están asociados y a lasprimeras evidencias de importantes alteraciones debidas a su mal funcionamiento.Nuestro grupo ha sido pionero en la caracterización estos receptores en el sistemanervioso, donde definimos su localización y su funcionalidad. La abundante presencia,a nivel presináptico, de las subunidades P2X3 y P2X7 debe ser resaltada,donde gracias a la entrada de calcio inducen la exocitosis de varios neurotransmisores,como glutamato, GABA, catecolaminas y acetilcolina entre otros, como hasido descrito por nuestro grupo en trabajos previos. Además, estos receptores inducenuna profunda remodelación del citoesqueleto de las terminales nerviosas yde los mecanismos exocitóticos a través de la CaMKII y pueden interactuar conotros receptores ionotrópicos y metabotrópicos co-existentes en sus cercanías. Lamayoría de los receptores P2Y también están presentes en las células nerviosas,activando vías de señalización a través de una gran variedad de cascadas intracelulares.Recientemente hemos demostrado que los receptores metabotrópicos P2Ypertenecientes a la sub-familia de receptores activados por ADP, especialmente elP2Y13, están conectados con la señalización hacia GSK3 y β-catenina, lo que abrenuevas vías para la comprensión de la función de los nucleótidos en la supervivenciay el mantenimiento de las células nerviosas. Además, tanto los receptores P2Xcomo los P2Y juegan un papel en los estadíos iniciales del desarrollo y en lamaduración neuronal donde su función aún ha de ser plenamente comprendida.Los receptores de nucleótidos son también muy abundantes en las células gliales, y nuestro grupo ha demostrado que la mayoría de los receptores P2Y están presentesy son plenamente funcionales en astrocitos en cultivo, donde, dependiendo delsubtipo de receptor, activan una gran variedad de cascadas de señalización

In the last few years nucleotide receptors, the ionotropic P2X1-7 subunits andthe metabotropic P2Y1, 2, 4, 6, 11, 12, 13, 14, have acquired an excepcional importance dueto their strategic location in organs and tissues, their great variety along with thecomplexity of the associated signalling pathways and the first evidence of theserious alterations entailed in their dysfunctions. Our group has been pioneer inthe characterization of these receptors in the nervous system, where we definedtheir location and functionality. The abundant presence, at a presynaptic level, ofP2X3 and P2X7 should be emphasized, where by means of calcium intake theyinduce neurotransmitter exocytosis, such as glutamate, GABA, catecholamines andacetylcholine among others, as described in previous works by our group. In addition, they induce an extensive remodeling of the terminal’s cytoskeleton and exocytoticmechanisms through CaMKII and they can interact widely with other ionotropicand metabotropic receptors co-existing in nearby areas. Neural cells alsoexhibit the presence of most P2Y receptors signalling through a large variety ofintracellular cascades. Recently we have demostrated that P2Y metabotropic receptorsof the sub-family activated by ADP, especially P2Y13, are connected withthe signalling towards GSK3 and Beta-catenin, opening new ways of understading thenucleotide function in survival and maintenance of neural cells. In addition bothP2X and P2Y receptors play a role in early developmental stages and neural maturationwhere their function has to be fully understanded. Nucleotide receptorsare also very abundant in glial cells, and our group has shown that most P2Yreceptors are present and fully functional in cultured astrocytes, where, dependingon the subtype receptor they activate a large variety of signalling cascades