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The systemic effects of physical activity are mediated by the release of IL-6 and other myokines from contracting muscle. Although the release of IL-6 from muscle has been extensively studied, the information on the cellular mechanisms is fragmentary and scarce, especially regarding the role of Ca2+ signals. The aim of this study was to characterize the role of the main components of Ca2+ signals in human skeletal muscle cells during IL-6 secretion stimulated by the Ca2+ mobilizing agonist ATP. Primary cultures were prepared from surgical samples, fluorescence microscopy was used to evaluate the Ca2+ signals and the stimulated release of IL-6 into the medium was determined using ELISA. Intracellular calcium chelator Bapta, low extracellular calcium and the Ca2+ channels blocker La3+ reduced the ATP-stimulated, but not the basal secretion. Secretion was inhibited by blockers of L-type (nifedipine, verapamil), T-type (NNC55-0396) and Orai1 (Synta66) Ca2+ channels and by silencing Orai1 expression. The same effect was achieved with inhibitors of ryanodine receptors (ryanodine, dantrolene) and IP3 receptors (xestospongin C, 2-APB, caffeine). Inhibitors of calmodulin (calmidazolium) and calcineurin (FK506) also decreased secretion. IL-6 transcription in response to ATP was not affected by Bapta or by the T channel blocker. Our results prove that ATP-stimulated IL-6 secretion is mediated at the post-transcriptional level by Ca2+ signals, including the mobilization of calcium stores, the activation of store-operated Ca2+ entry, and the subsequent activation of voltage-operated Ca2+ channels and calmodulin/calcineurin pathways.

Resumen: Introducción: La alergia alimentaria es un problema creciente, siendo la proteína de leche de vaca la principal causa en niños. Sin un proceso diagnóstico adecuado, existe un elevado riesgo de sobrediagnóstico e infradiagnóstico y, por lo tanto, de sobretratamiento e infratratamiento. El objetivo de nuestro estudio fue analizar la variabilidad en el manejo de la alergia a proteína de leche de vaca (APLV) por los gastroenterólogos pediátricos españoles. Métodos: Se envió un cuestionario de 50 preguntas a través de la lista de email de la Sociedad Española de Gastroenterología, Hepatología y Nutrición Pediátricas. Resultados: Recibimos 73 cuestionarios de los 321 enviados. Solo 3 de las respuestas lograron más del 90% de acuerdo. El 33% considera que la provocación oral es necesaria para el diagnóstico de APLV siempre. El 25% considera que la mejoría clínica tras la retirada de las proteínas de leche de vaca es suficiente para el diagnóstico. La provocación oral es realizada en domicilio por el 83,5% de los encuestados en APLV no IgE mediada. Los hidrolizados extensos de caseína son el tratamiento de elección (69,9%). Las fórmulas de soja, la última opción. Casi todos los encuestados conocían la existencia de guías de manejo de APLV, siendo las de la Sociedad Europea de Gastroenterología, Hepatología y Nutrición Pediátrica las más utilizadas (64,4%). El 23% considera que su conocimiento sobre alergia es inadecuado. Conclusiones: Aunque la APLV es una patología prevalente que los gastroenterólogos pediátricos llevan décadas tratando, hemos encontrado una gran variabilidad en su manejo. Existe posibilidad de mejora en este campo en el futuro. Abstract: Introduction: Food allergy is an increasing health problem in the developed world. Cow's milk protein is the main cause of food allergy in infants. Without an appropriate diagnostic workup, there is a high risk of both over- and underdiagnosis and therefore, over and undertreatment. The objective of our study was to analyze the variability in cow's milk protein allergy (CMPA) management by pediatric gastroenterologists in Spain. Methods: A fifty item questionnaire, including open and closed items in a Likert's scale from 0 to 5, was drafted and distributed through the Spanish Society for Pediatric Gastroenterology, Hepatology and Nutrition (SEGHNP) e-mail list. Results: Seventy-three questionnaires were received back out of 321. Only 3 of the items achieved concordance greater than 90%. Thirty-three percent considered oral challenge to be necessary for the diagnosis of CMPA under any circumstance. Twenty-five percent considered that symptom improvement after cow's milk removal was enough for the diagnosis. Oral challenge was performed at home by 83.5% in non-IgE mediated cases. Extensively hydrolyzed casein formulas were the treatment of choice for 69.9%. Soy formulas were the last option. Almost all respondents were aware of the existence of clinical guidelines on CMPA, being European Society of Pediatric Gastroenterology, Hepatology and Nutrition guidelines the most followed (64.4%). Twenty-three percent considered that their knowledge about allergy was inadequate. Conclusions: Although CMPA is a prevalent condition that pediatric gastroenterologists have been treating for decades, we found a huge variability on its management. There is potential for improvement in this field among pediatric gastroenterologist in the future.

Introduction: Food allergy is an increasing health problem in the developed world. Cow's milk protein is the main cause of food allergy in infants. Without an appropriate diagnostic workup, there is a high risk of both over- and underdiagnosis and therefore, over and undertreatment. The objective of our study was to analyze the variability in cow's milk protein allergy (CMPA) management by pediatric gastroenterologists in Spain. Methods: A 50 item questionnaire, including open and closed items in a Likert's scale from 0 to 5, was drafted and distributed through the Spanish Society for Pediatric Gastroenterology, Hepatology and Nutrition (SEGHNP) e-mail list. Results: Seventy-three questionnaires were received back out of 321. Only 3 of the items achieved concordance greater than 90%. Thirty-three percent considered oral challenge to be necessary for the diagnosis of CMPA under any circumstance. Twenty-five percent considered that symptom improvement after cow's milk removal was enough for the diagnosis. Oral challenge was performed at home by 83.5% in non-IgE mediated cases. Extensively hydrolyzed casein formulas were the treatment of choice for 69.9%. Soy formulas were the last option. Almost all respondents were aware of the existence of clinical guidelines on CMPA, being European Society of Pediatric Gastroenterology, Hepatology and Nutrition guidelines the most followed (64.4%). Twenty-three percent considered that their knowledge about allergy was inadequate. Conclusions: Although CMPA is a prevalent condition that pediatric gastroenterologists have been treating for decades, we found a huge variability on its management. There is potential for improvement in this field among pediatric gastroenterologist in the future. Resumen: Introducción: La alergia alimentaria es un problema creciente, siendo la proteína de leche de vaca la principal causa en niños. Sin un proceso diagnóstico adecuado, existe un elevado riesgo de sobrediagnóstico e infradiagnóstico y, por lo tanto, de sobretratamiento e infratratamiento. El objetivo de nuestro estudio fue analizar la variabilidad en el manejo de la alergia a proteína de leche de vaca (APLV) por los gastroenterólogos pediátricos españoles. Métodos: Se envió un cuestionario de 50 preguntas a través de la lista de email de la Sociedad Española de Gastroenterología, Hepatología y Nutrición Pediátricas. Resultados: Recibimos 73 cuestionarios de los 321 enviados. Solo 3 de las respuestas lograron más del 90% de acuerdo. El 33% considera que la provocación oral es necesaria para el diagnóstico de APLV siempre. El 25% considera que la mejoría clínica tras la retirada de las proteínas de leche de vaca es suficiente para el diagnóstico. La provocación oral es realizada en domicilio por el 83,5% de los encuestados en APLV no IgE mediada. Los hidrolizados extensos de caseína son el tratamiento de elección (69,9%). Las fórmulas de soja, la última opción. Casi todos los encuestados conocían la existencia de guías de manejo de APLV, siendo las de la Sociedad Europea de Gastroenterología, Hepatología y Nutrición Pediátrica las más utilizadas (64,4%). El 23% considera que su conocimiento sobre alergia es inadecuado. Conclusiones: Aunque la APLV es una patología prevalente que los gastroenterólogos pediátricos llevan décadas tratando, hemos encontrado una gran variabilidad en su manejo. Existe posibilidad de mejora en este campo en el futuro.

Simple Summary: Skeletal muscle releases numerous hormones into circulation that interact with other organs, such as the liver, bone or the brain. These hormones, termed myokines, mediate the effects of physical activity in health, aging and disease. Interleukin 6 was the first discovered myokine and is actively investigated due to its participation in inflammation, immunity and metabolism. However, there is little information regarding the mechanisms that induce its release from muscle cells, especially in humans. Our aim was to investigate whether changes in the concentration of calcium ions participate in the stimulated release of interleukin 6 in human muscle cells. Using muscle cultures, we have found that several proteins responsible for the calcium increase during stimulation induce the release of interleukin 6 from the muscle cells. This could help to unveil how interleukin 6 and other myokines are released in pathological conditions such as trauma, infections or cancer. The systemic effects of physical activity are mediated by the release of IL-6 and other myokines from contracting muscle. Although the release of IL-6 from muscle has been extensively studied, the information on the cellular mechanisms is fragmentary and scarce, especially regarding the role of Ca2+ signals. The aim of this study was to characterize the role of the main components of Ca2+ signals in human skeletal muscle cells during IL-6 secretion stimulated by the Ca2+ mobilizing agonist ATP. Primary cultures were prepared from surgical samples, fluorescence microscopy was used to evaluate the Ca2+ signals and the stimulated release of IL-6 into the medium was determined using ELISA. Intracellular calcium chelator Bapta, low extracellular calcium and the Ca2+ channels blocker La3+ reduced the ATP-stimulated, but not the basal secretion. Secretion was inhibited by blockers of L-type (nifedipine, verapamil), T-type (NNC55-0396) and Orai1 (Synta66) Ca2+ channels and by silencing Orai1 expression. The same effect was achieved with inhibitors of ryanodine receptors (ryanodine, dantrolene) and IP3 receptors (xestospongin C, 2-APB, caffeine). Inhibitors of calmodulin (calmidazolium) and calcineurin (FK506) also decreased secretion. IL-6 transcription in response to ATP was not affected by Bapta or by the T channel blocker. Our results prove that ATP-stimulated IL-6 secretion is mediated at the post-transcriptional level by Ca2+ signals, including the mobilization of calcium stores, the activation of store-operated Ca2+ entry, and the subsequent activation of voltage-operated Ca2+ channels and calmodulin/calcineurin pathways. [ABSTRACT FROM AUTHOR]