Lysophosphatidic Acid Receptor 3 (LPA3): Signaling and Phosphorylation Sites.

LPA3 receptors were expressed in TREx HEK 293 cells, and their signaling and phosphorylation were studied. The agonist, lysophosphatidic acid (LPA), increased intracellular calcium and ERK phosphorylation through pertussis toxin-insensitive processes. Phorbol myristate acetate, but not LPA, desensitizes LPA3-mediated calcium signaling, the agonists, and the phorbol ester-induced LPA3 internalization. Pitstop 2 (clathrin heavy chain inhibitor) markedly reduced LPA-induced receptor internalization; in contrast, phorbol ester-induced internalization was only delayed. LPA induced rapid ß-arrestin-LPA3 receptor association. The agonist and the phorbol ester-induced marked LPA3 receptor phosphorylation, and phosphorylation sites were detected using mass spectrometry. Phosphorylated residues were detected in the intracellular loop 3 (S221, T224, S225, and S229) and in the carboxyl terminus (S321, S325, S331, T333, S335, Y337, and S343). Interestingly, phosphorylation sites are within sequences predicted to constitute ß-arrestin binding sites. These data provide insight into LPA3 receptor signaling and regulation.

LPA3 Receptor Phosphorylation Sites: Roles in Signaling and Internalization.

Lysophosphatidic acid (LPA) type 3 (LPA3) receptor mutants were generated in which the sites detected phosphorylated were substituted by non-phosphorylatable amino acids. Substitutions were made in the intracellular loop 3 (IL3 mutant), the carboxyl terminus (Ctail), and both domains (IL3/Ctail). The wild-type (WT) receptor and the mutants were expressed in T-REx HEK293 cells, and the consequences of the substitutions were analyzed employing different functional parameters. Agonist- and LPA-mediated receptor phosphorylation was diminished in the IL3 and Ctail mutants and essentially abolished in the IL3/Ctail mutant, confirming that the main phosphorylation sites are present in both domains and their role in receptor phosphorylation eliminated by substitution and distributed in both domains. The WT and mutant receptors increased intracellular calcium and ERK 1/2 phosphorylation in response to LPA and PMA. The agonist, Ki16425, diminished baseline intracellular calcium, which suggests some receptor endogenous activity. Similarly, baseline ERK1/2 phosphorylation was diminished by Ki16425. An increase in baseline ERK phosphorylation was detected in the IL3/Ctail mutant. LPA and PMA-induced receptor interaction with ß-arrestin 2 and LPA3 internalization were severely diminished in cells expressing the mutants. Mutant-expressing cells also exhibit increased baseline proliferation and response to different stimuli, which were inhibited by the antagonist Ki16425, suggesting a role of LPA receptors in this process. Migration in response to different attractants was markedly increased in the Ctail mutant, which the Ki16425 antagonist also attenuated. Our data experimentally show that receptor phosphorylation in the distinct domains is relevant for LPA3 receptor function.

Roles of the α1B-Adrenergic Receptor Phosphorylation Domains in Signaling and Internalization.

The function of the α1B-adrenergic receptor phosphorylation sites previously detected by mass spectrometry was evaluated by employing mutants, substituting them with non-phosphorylatable amino acids. Substitution of the intracellular loop 3 (IL3) sites did not alter baseline or stimulated receptor phosphorylation, whereas substitution of phosphorylation sites in the carboxyl terminus (Ctail) or both domains (IL3/Ctail) markedly decreased receptor phosphorylation. Cells expressing the IL3 or Ctail receptor mutants exhibited a noradrenaline-induced calcium-maximal response similar to those expressing the wild-type receptor, and a shift to the left in the concentration-response curve to noradrenaline was also noticed. Cells expressing the IL3/Ctail mutant exhibited higher apparent potency and increased maximal response to noradrenaline than those expressing the wild-type receptor. Phorbol ester-induced desensitization of the calcium response to noradrenaline was reduced in cells expressing the IL3 mutant and abolished in cells in which the Ctail or the IL3/Ctail were modified. In contrast, desensitization in response to preincubation with noradrenaline was unaffected in cells expressing the distinct receptor mutants. Noradrenaline-induced ERK phosphorylation was surprisingly increased in cells expressing IL3-modified receptors but not in those expressing receptors with the Ctail or IL3/Ctail substitutions. Our data indicate that phosphorylation sites in the IL3 and Ctail domains mediate and regulate α1B-adrenergic receptor function. Phorbol ester-induced desensitization seems to be closely associated with receptor phosphorylation, whereas noradrenaline-induced desensitization likely involves other elements.

Aproximaciones a la epidemiología de la neuropatía óptica hereditaria de Leber en la comunidad autónoma de Madrid a través de una encuesta a los neuroftalmólogos / Approaches to the epidemiology of NOHL in the region of Madrid: Survey of neuro-ophthalmologists

Objective To estimate the epidemiology of Leber's optic neuropathy (NOHL) in the Region of Madrid. Material and methodsThe neuro-ophthalmologists who work at public hospitals of the CAM were interviewed by telephone. They were asked about the number of patients with NOHL that they had diagnosed during the time that they had been responsible for the neuro-ophthalmology department of that public hospital. The time worked and the population attended by the hospital were used to calculate the number of patient-years in follow-up by each center during the corresponding period. The basic information of each case (date of birth, mutation, and date of visual loss) was registered to avoid duplications. Results Our work estimates a global incidence of 2.34 cases for 10,000,000 inhabitants-year and a prevalence estimated from incidence of one case for each 106,682 inhabitants. This prevalence was very similar in all the studied areas and considerably lower than that reported by other studies. Conclusion This work constitutes the first approach to the epidemiology of this disease in Spain. The prevalence of NOHL in the region of Madrid is probably lower than that reported in the literature in other regions. The prevalence and the incidence were homogeneously low in the 26 studied areas. (AU)

Objetivo Estimar la epidemiología (incidencia y prevalencia) de la neuropatía óptica de Leber (NOHL) en la comunidad autónoma de Madrid (CM). Material y métodosLos neuroftalmólogos que trabajan en los hospitales públicos de la CAM fueron entrevistados telefónicamente. Se les preguntó por el número de pacientes con NOHL que habían diagnosticados durante el tiempo que han sido responsables de la consulta de neuroftalmología de ese hospital público. El tiempo trabajado y la población atendida por el hospital se utilizaron para calcular el número de habitantes-años en seguimiento por cada centro durante el periodo correspondiente y estimar la incidencia en cada área. La prevalencia estimada a partir de la incidencia (PEI) se calculó considerando que un paciente con NOHL vive unos 40 años con la enfermedad. Se registró la información básica de cada caso cuando estaba disponible (sexo, fecha de nacimiento, mutación, fecha de la pérdida visual) para evitar duplicaciones. Resultados Nuestro trabajo estima una incidencia global de 2,34 casos por cada 10.000.000 habitantes-año y una PEI de 1 caso por cada 106.682 habitantes. Esta prevalencia es inferior a la referida por otros estudios. Conclusión Este trabajo constituye la primera aproximación a la epidemiología de esta enfermedad en España. La prevalencia estimada de la NOHL en la CM es probablemente inferior a la reportada en la literatura en otras regiones. La prevalencia y la incidencia fueron homogéneamente bajas en las 26 áreas estudiadas. (AU)

Approaches to the epidemiology of NOHL in the region of Madrid: Survey of neuro-ophthalmologists.

OBJECTIVE: To estimate the epidemiology of Leber's optic neuropathy (NOHL) in the Region of Madrid. MATERIAL AND METHODS: The neuro-ophthalmologists who work at public hospitals of the CAM were interviewed by telephone. They were asked about the number of patients with NOHL that they had diagnosed during the time that they had been responsible for the neuro-ophthalmology department of that public hospital. The time worked and the population attended by the hospital were used to calculate the number of inhabitant-years in follow-up by each center during the corresponding period. The basic information of each case (date of birth, mutation, date of visual loss) was registered to avoid duplications. RESULTS: Our work estimates a global incidence of 2.34 cases for 10,000,000 inhabitants-year and a prevalence estimated from incidence of one case for each 106.682 inhabitants. This prevalence was very similar in all the studied areas and considerably lower than that reported by other studies. CONCLUSION: This work constitutes the first approach to the epidemiology of this disease in Spain. The prevalence of LHON in the region of Madrid, is probably lower than that reported in the literature in other regions. The prevalence and the incidence were homogeneously low in the 26 studied areas.

Descripción de un caso de hernia diafragmática de Morgagni con derrame pericárdico masivo resuelto mediante pericardiocentesis intrauterina / Description of a case of Morgagni's diaphragmatic hernia with massive pericardial effusion resolved by intrauterine pericardiocentesis

Introducción: Las hernias diafragmáticas de Morgagni diagnosticadas prenatalmente son una rara entidad, con menor riesgo asociado de hipoplasia pulmonar y problemas respiratorios que las hernias diafragmáticas posteriores. Nuestro caso pone de manifiesto cómo en los casos de hernia diafragmática de Morgagni los pulmones tienden a desarrollarse completamente, a pesar del significativo derrame pericárdico o cuán disminuidos pueden aparentar. Principales síntomas y/o hallazgos clínicos: Hernia diafragmática de Morgagni diagnosticada a las 14 semanas de gestación, con derrame pericárdico masivo y herniación torácica anterior del hígado. Diagnósticos principales, intervenciones terapéuticas y resultados: No se identificaron otras malformaciones asociadas, se descartaron otras causas de derrame pericárdico y el cariotipo fetal analizado fue normal. A las 25 semanas, se realizó una pericardiocentesis fetal intrauterina, consiguiendo una significativa distensión pulmonar, con una adecuada vascularización. Tras el nacimiento, la recién nacida precisó soporte ventilatorio debido a una hipoxemia severa causada por la hipertensión pulmonar, corrigiéndose el defecto quirúrgicamente a los 6 días de vida. La evolución posterior fue favorable, sin presentar problemas respiratorios significativos. Conclusión: La detección ecográfica de esta rara anomalía resulta útil para el manejo óptimo, y el drenaje pericárdico puede favorecer una resolución prenatal del derrame pericárdico, permitiéndonos evaluar de forma adecuada el riesgo de hipoplasia pulmonar.(AU)

Introduction: Morgagni diaphragmatic hernia with prenatal diagnosis is a rare entity, with lower risk of pulmonary hypoplasia and respiratory problems than posterior diaphragmatic hernia. Our case highlights how in Morgagni diaphragmatic hernia cases lungs tend to develop properly, despite significant pericardial effusion or how greatly diminished they may seem. Main symptoms and/or clinical findings: Morgagni diaphragmatic hernia diagnosed at 14 weeks, with massive pericardial effusion and anterior thoracic herniation of the liver. Main diagnosis, therapeutic interventions, and results: No other malformations were identified, other causes of pericardial effusion were ruled out and foetal karyotype was normal. At 25 weeks, in-utero pericardiocentesis was performed, observing significant pulmonary distension and adequate vascularization. After delivery, the newborn required respiratory support due to severe hypoxaemia related to pulmonary hypertension. Six days later surgical diaphragm closure was performed. The newborn had no significant respiratory problems and progressed positively after surgery. Conclusion: Ultrasonographic detection of this rare anomaly is useful for optimal management, and pericardial drainage can provide prenatal resolution of pericardial effusion, enabling us to evaluate pulmonary hypoplasia risk.(AU)

Cell Trafficking and Function of G Protein-coupled Receptors.

The G protein-coupled receptors (GPCRs) are plasma membrane proteins that function as sensors of changes in the internal and external milieux and play essential roles in health and disease. They are targets of hormones, neurotransmitters, local hormones (autacoids), and a large proportion of the drugs currently used as therapeutics and for "recreational" purposes. Understanding how these receptors signal and are regulated is fundamental for progress in areas such as physiology and pharmacology. This review will focus on what is currently known about their structure, the molecular events that trigger their signaling, and their trafficking to endosomal compartments. GPCR phosphorylation and its role in desensitization (signaling switching) are also discussed. It should be mentioned that the volume of information available is enormous given the large number and variety of GPCRs. However, knowledge is fragmentary even for the most studied receptors, such as the adrenergic receptors. Therefore, we attempt to present a panoramic view of the field, conscious of the risks and limitations (such as oversimplifications and incorrect generalizations). We hope this will provoke further research in the area. It is currently accepted that GPCR internalization plays a role signaling events. Therefore, the processes that allow them to internalize and recycle back to the plasma membrane are briefly reviewed. The functions of cytoskeletal elements (mainly actin filaments and microtubules), the molecular motors implicated in receptor trafficking (myosin, kinesin, and dynein), and the GTPases involved in GPCR internalization (dynamin) and endosomal sorting (Rab proteins), are discussed. The critical role phosphoinositide metabolism plays in regulating these events is also depicted.

Mitogen-activated protein kinase inhibitor-associated retinopathy (MEKAR). A clinical case.

Mitogen-activated protein kinase kinase (MEK) inhibitors have significantly improved the prognosis of various types of cancer such as metastatic melanoma. However, their use is usually associated with ocular side effects. A retinopathy associated with these agents (MEKAR) has been described, consisting of the development of neurosensory detachments, generally bilateral and multiple, similar to those that appear in the central serous chorioretinopathy (CSC). Generally, optical coherence tomography allows us to differentiate the two conditions. We present the case of a 55-year-old woman in treatment with a MEK inhibitor, who developed bilateral neurosensory detachments and blurred vision, which resolved with the discontinuance of the treatment due to tumour progression.

Retinopatía asociada a inhibidor de la proteinquinasa de activación mitogénica (MEKAR). A propósito de un caso / Mitogen-activated protein kinase inhibitor-associated retinopathy (MEKAR). A clinical case

Los inhibidores de la proteína quinasa de activación mitogénica (MEK) son fármacos utilizados para el tratamiento de neoplasias tales como el melanoma metastásico. Su introducción ha mejorado el pronóstico de estas enfermedades, pero su uso no está exento de complicaciones oculares. Se ha descrito una retinopatía asociada a estos fármacos (MEKAR) consistente en la aparición de desprendimientos neurosensoriales (DNS), generalmente bilaterales y múltiples similares a los que aparecen en la coriorretinopatía serosa central (CSC). En la mayoría de los casos la tomografía de coherencia óptica es suficiente para diferenciar esta entidad de una CSC. Presentamos el caso de una paciente de 55 años que, en este contexto, desarrolló DNS bilaterales que asociaron disminución de agudeza visual y que se resolvieron cuando se suspendió la terapia por progresión tumoral (AU)

Mitogen-activated protein kinase kinase (MEK) inhibitors have significantly improved the prognosis of various types of cancer such as metastatic melanoma. However, their use is usually associated with ocular side effects. A retinopathy associated with these agents (MEKAR) has been described, consisting of the development of neurosensory detachments, generally bilateral and multiple, similar to those that appear in the central serous chorioretinopathy (CSC). Generally, optical coherence tomography allows us to differentiate the two conditions. We present the case of a 55-year-old woman in treatment with a MEK inhibitor, who developed bilateral neurosensory detachments and blurred vision, which resolved with the discontinuance of the treatment due to tumour progression (AU)

Systematic training in master swimmer athletes increases serum insulin growth factor-1 and decreases myostatin and irisin levels.

During ageing, anabolic status is essential to prevent the decrease in quantity and quality of skeletal muscle mass (SMM). Exercise modulates endocrine markers of muscle status. We studied the differences of endocrine markers for muscle status in 62 non-sarcopenic Mexican swimmer adults aged 30-70 y/o, allocated into two groups: the systematic training (ST) group including master athletes with a physical activity level (PAL) >1.6, and the non-systematic training group (NST) composed by subjects with a PAL <1.5. Body composition, diet, biochemical and endocrine markers were analyzed. The ST group showed lower myostatin (MSTN) and irisin (IRI) levels, two strong regulators of SMM. The insulin growth factor-1 (IGF-1) was higher in the ST. This is consistent with most of the evidence in young athletes and resistance training programs, where IGF-1 and IRI seem to play a crucial role in maintaining anabolic status in master athletes.

Mutation of putative phosphorylation sites in the free fatty acid receptor 1: Effects on signaling, receptor phosphorylation, and internalization.

Free fatty acid receptor 1 phosphorylation sites were studied using mutants, including a) a mutant with T215V in the third intracellular loop (3IL), b) another with changes in the carboxyl terminus (C-term): T287V, T293V, S298A, and c) a mutant with all of these changes (3IL/C-term). Agonist-induced increases in intracellular calcium were similar between cells expressing wild-type or mutant receptors. In contrast, agonist-induced FFA1 receptor phosphorylation was reduced in mutants compared to wild type. Phorbol ester-induced FFA1 receptor phosphorylation was rapid and robust in cells expressing the wild-type receptor and essentially abolished in the mutants. Agonist-induced ERK 1/2 phosphorylation and receptor internalization were decreased in cells expressing the mutant receptors compared to those expressing the wild-type receptor. Our data suggest that the identified sites might participate in receptor phosphorylation, signaling, and internalization.

Evaluation of the insertion distance of the medial rectus in consecutive exotropia by means of intraoperative measure and optical coherence tomography.

PURPOSE: To assess the agreement between the measurements of the distance from the medial rectus muscles insertion to the limbus measured by intra-operative spectral-domain optical coherence tomography (SD-OCT) in consecutive exotropia (cXT). METHODS: An analysis was performed on total of 14 medial rectus (MR) muscles of 14 patients who underwent surgery for the treatment of cXT. The limbus-insertion distance of the MR muscles was measured using preoperative SD-OCT and intraoperatively using a calliper. The intraclass correlation coefficient (ICC) and Bland Altman plots were calculated to determine the agreement between the two methods, as well as the correlation. RESULTS: Mean age was 36.3 ± 16.0 years (range 13-60), with 60% being women. Mean preoperative deviation was 38.7 ± 16.9 prismatic dioptres (PD) (range 16-65), being +1.3 ± 6.3 PD (range -12 to +10 PD) after surgery. Intraoperatively the MR insertion was found at 8.7 ± 2.1 mm (range 5.5-12.0) and by OCT at 7.7 ± 1.2 mm (range 5.3-10.0). The ICC showed a moderate to good agreement (0.659; 95% confidence interval: 0.157-0.885; p < 0.001), with a correlation of R = 0.792 (p = 0.011). A better agreement was observed in those MR that were less retro-inserted. CONCLUSIONS: SD-OCT is able to measure the insertion to the limbus distance of the medial rectus muscles that have been previously operated on, showing moderate to good agreement with intraoperative measurements. However, the agreement was poor in muscles with a large retro-insertion.

A variant Nishida's technique for surgical correction of monocular elevation deficiency syndrome.

Monocular elevation deficiency (MED) is characterized by unilateral limitation of supraductions, similar in adduction and abduction, in addition to hypotropia and ptosis. We describe a case of a 62-year-old woman with long-standing left ptosis who was initially operated with a frontal suspension technique. On subsequent examinations, a MED of that eye was found. The passive duction test was positive, so the inferior rectus was recessed. In addition, a modified Nishida technique was performed, consisting of the scleral anchorage of the superior edges of the rectus, medial and lateral, 12mm from the corneal limbus in the superonasal and superotemporal quadrants, respectively. Postoperatively, the left eye presented a minimal hypotropia of 3 PD. This modified technnique used here on the horizontal rectus muscles, turned out to be effective and safe for the correction of MED.

Purtscher-like retinopathy after a stent implant for the treatment of carotid aneurysm.

Purtscher retinopathy is an occlusive microangiopathy associated with traumatic causes and usually causes visual impairment. For non-traumatic origins, it is called Purtscher-like retinopathy (PLR). A 26-year-old man reported loss of vision in his left eye after the implantation of a telescoping stent for the treatment of an intracranial carotid aneurysm. The fundus of the eye showed numerous cotton-wool spots and superficial haemorrhages. The spontaneous evolution was favourable, with almost complete resolution, except for an inferior residual scotoma. The appearance of PLR may be associated with the implantation of an endovascular stent for the treatment of intracranial aneurysms.

Retinopatía de tipo Purtscher tras implante de stent para el tratamiento de aneurisma carotídeo / Purtscher-like retinopathy after a stent implant for the treatment of carotid aneurysm

La retinopatía de Purtscher es una microangiopatía oclusiva asociada a causas traumáticas que suele cursar con disminución visual. Cuando la etiología no es traumática se denomina retinopatía Purtscher-like (RPL). Un varón de 26años refirió pérdida de visión en el ojo izquierdo tras el implante de un stent telescopado para el tratamiento de un aneurisma carotídeo intracraneal. El fondo de ojo mostró numerosos exudados algodonosos y hemorragias superficiales. La evolución espontánea fue favorable, con una resolución casi completa salvo por un escotoma residual inferior. La aparición de RPL se puede asociar al implante de un stent endovascular para el tratamiento de aneurismas intracraneales (Au)

Purtscher retinopathy is an occlusive microangiopathy associated with traumatic causes and usually causes visual impairment. For non-traumatic origins, it is called Purtscher-like retinopathy (PLR). A 26-year-old man reported loss of vision in his left eye after the implantation of a telescoping stent for the treatment of an intracranial carotid aneurysm. The fundus of the eye showed numerous cotton-wool spots and superficial haemorrhages. The spontaneous evolution was favourable, with almost complete resolution, except for an inferior residual scotoma. The appearance of PLR may be associated with the implantation of an endovascular stent for the treatment of intracranial aneurysms (AU)

The LPA3 Receptor: Regulation and Activation of Signaling Pathways.

The lysophosphatidic acid 3 receptor (LPA3) participates in different physiological actions and in the pathogenesis of many diseases through the activation of different signal pathways. Knowledge of the regulation of the function of the LPA3 receptor is a crucial element for defining its roles in health and disease. This review describes what is known about the signaling pathways activated in terms of its various actions. Next, we review knowledge on the structure of the LPA3 receptor, the domains found, and the roles that the latter might play in ligand recognition, signaling, and cellular localization. Currently, there is some information on the action of LPA3 in different cells and whole organisms, but very little is known about the regulation of its function. Areas in which there is a gap in our knowledge are indicated in order to further stimulate experimental work on this receptor and on other members of the LPA receptor family. We are convinced that knowledge on how this receptor is activated, the signaling pathways employed and how the receptor internalization and desensitization are controlled will help design new therapeutic interventions for treating diseases in which the LPA3 receptor is implicated.

Orbital apex syndrome secondary to herpes zoster ophthalmicus.

Herpes zoster ophthalmicus usually presents with ocular manifestations, but neurological complications are much more infrequent. An 84-year-old woman with herpes zoster of the left first trigeminal branch developed herpetic keratouveitis in her left eye despite treatment with oral valaciclovir. Seven days later, a progressive and total left ophthalmoplegia appeared, requiring hospital admission and intravenous treatment with acyclovir and corticosteroids. The neuroimaging was suggestive of an orbital apex syndrome. The evolution of the ophthalmoplegia was favourable, with complete resolution at 5 months, but with decreased visual acuity due to the optic nerve involvement.