Teaching biological rhythms in endocrinology: cortisol and wrist temperature. Póster

This work has been developed as part of the Endocrinology and Metabolism student’s laboratory formation from Biology degree at the University of Murcia. Endocrinology and Metabolism is an elective oneterm course that is taught in the fourth year (4.5 ECTS) for "Biosanitary and Biotechnology" intensification. The course focuses on the study of global and intermediary human metabolism and hormonal regulation, both under normal and special situations. It is our objective to get undergraduate students of Endocrinology and Metabolism with the importance of hormonal diurnal fluctuations in endocrine systems through their involvement in an innovative research program. In addition, with the participation of PhD student in this program, we try to improve their skills in innovative teaching. In humans cortisol circadian rhythm peaks in the morning and shows the lowest levels during the midnight. This fluctuation of cortisol plasma level is reflected in saliva, allowing a simple, non invasive and unstressful sample collection. The influence of different factors, exercise, schedule and weekend shifts, on the rhythmic pattern of cortisol has been studied along various years.Campus Mare Nostrum, Universidad Politécnica de Cartagena, Universidad de Murcia, Región de Murci

Age and Chronodisruption in Mouse Heart: Effect of the NLRP3 Inflammasome and Melatonin Therapy

Age and age-dependent inflammation are two main risk factors for cardiovascular diseases. Aging can also affect clock gene-related impairments such as chronodisruption and has been linked to a decline in melatonin synthesis and aggravation of the NF- B/NLRP3 innate immune response known as inflammaging. The molecular drivers of these mechanisms remain unknown. This study investigated the impact of aging and NLRP3 expression on the cardiac circadian system, and the actions of melatonin as a potential therapy to restore daily rhythms by mitigating inflammaging. We analyzed the circadian expression and rhythmicity of clock genes in heart tissue of wild-type and NLRP3-knockout mice at 3, 12, and 24 months of age, with and without melatonin treatment. Our results support that aging, NLRP3 inflammasome, and melatonin affected the cardiac clock genes expression, except for Rev-erba, which was not influenced by genotype. Aging caused small phase changes in Clock, loss of rhythmicity in Per2 and Rora, and mesor dampening of Clock, Bmal1, and Per2. NLRP3 inflammasome influenced the acrophase of Clock, Per2, and Rora. Melatonin restored the acrophase and the rhythm of clock genes affected by age or NLRP3 activation. The administration of melatonin re-established murine cardiac homeostasis by reversing age-associated chronodisruption. Altogether, these results highlight new findings about the effects aging and NLRP3 inflammasome have on clock genes in cardiac tissue, pointing to continuous melatonin as a promising therapy to placate inflammaging and restore circadian rhythm in heart muscle. Additionally, light microscopy analysis showed age-related morphological impairments in cardiomyocytes, which were less severe in mice lacking NLRP3. Melatonin supplementation preserved the structure of cardiac muscle fibers in all experimental groups.Instituto de Salud Carlos III (Ministerio de Economia y Competitividad, Spain) (European Regional Development Fund/European Social Fund "Investing in your future") PI13-981 PI16-00519 PI19-01372 CB16-10-00238 CB16/10/00239Junta de Andalucia CTS-101Spanish Governmen

Ritmos, relojes y relojeros. Una introducción a la Cronobiología.

1.- En respuesta a la selección natural, los organismos han desarrollado relojes biológicos, lo que proporciona a los organismos dos ventajas competitivas: i) anticiparse a los cambios periódicos en el ambiente , y ii) generar un orden interno en los procesos fisiológicos, bioquímicos y comportamentales. 2.-Los estudios clínicos y epidemiológicos han demostrado la asociación existente entre la disrupción del sistema circadiano y algunas de las patologías frecuentes en los países desarrollados, tales como cáncer, obesidad, síndrome metabólico, insomnio, alteraciones cognitivas y afectivas y envejecimiento prematuro. 3.-El papel clave que juega el sistema circadiano en mantener la salud subraya la importancia de la puesta a punto de técnicas que permitan evaluar su funcionamiento de forma objetiva. No obstante, la estandarización del registro ambulatorio basado en sensores vestibles, todavía constituye un desafío para el desarrollo de la cronobiología clínica

Evaluación de la fase circadiana mediante monitorización ambulatoria en humanos: correlación con el dim light melatonin onset

RESUMEN Es fundamental desarrollar un sistema que detecte la fase endógena de forma sencilla, ya que las actuales técnicas implican cuantificación de melatonina o monitorización de temperatura central mediante sondas rectales. En este trabajo se validó un sistema de registro ambulatorio. Las variables monitorizadas, durante 10 días en 13 sujetos, fueron temperatura periférica, mediante un sensor en la muñeca; actividad y posición, utilizando un actímetro en el brazo; y luz, mediante un sensor colgado alrededor del cuello. Se obtuvo el marcador de fase estándar dim light melatonin onset (DLMO) en saliva para evaluar la precisión de las demás variables. Además, rellenaron un diario de sueño que evaluó la probabilidad de sueño y los cuestionarios de matutinidad-vespertinidad (Horne-Östberg), de calidad de sueño (Pittsburgh) y de somnolencia (Epworth) para evaluar la preferencia diurna y su influencia en la calidad del sueño. El aumento vespertino de la temperatura periférica se produjo con anterioridad a la elevación de melatonina; el descenso en la actividad, la posición, la variable compuesta TAP, y el aumento en la probabilidad de sueño, con posterioridad al incremento de melatonina. Las puntuaciones de los cuestionarios de matutinidad-vespertinidad y calidad del sueño mostraron alta correlación con el DLMO, confirmando que DLMO tardíos implican mayor vespertinidad y peor calidad del sueño. Este método permite detectar de manera precisa la fase del sistema circadiano sin modificar los hábitos de vida. Los nuevos marcadores de fase propuestos basados en el ritmo de temperatura periférica (WTOn and WTiO) serían adecuados en ámbitos clínicos en los que es fundamental conocer la fase circadiana del sujeto, como en la cronoterapia del cáncer y en la luminoterapia.ABSTRACT It is important to develop a system able to detect the endogenous circadian phase easily, since current techniques imply quantification of hormones or monitorization of central temperature by rectal probes. In this work, a new ambulatory circadian monitoring system was validated. The variables were recorded for 10 days in 13 healthy subjects, and they were: peripheral temperature, by means of a sensor located on the ventral side of the wrist; motor activity and position, by an actimeter on the arm; and light exposure, using a pendant sensor. DLMO was also obtained in saliva to evaluate the accuracy of the rest of variables to asses the circadian phase. Besides, they completed a sleep log to obtain the sleep probability and Horne-Östberg morningness-eveningness, Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale questionnaires to evaluate diurnal preference and its influence in sleep quality. The evening increase in peripheral temperature anticipated the evening increase in melatonin; while the decrease in motor activity, position and TAP, and the increase in sleep probability took place after the increase in melatonin levels. The score of morningness-eveningness and sleep quality questionnaires showed high correlations with DLMO, confirming that late DLMO indicate higher eveningness and worse sleep quality. This method allows accurately detecting the circadian phase without modifying subjects life style. The proposed new phase markers based on wrist temperature rhythm (WTOn and WTiO) would be appropriate in Clinics when it is important to know the subject circadian phase, like in cancer chronotherapy or light therapy

Dormir bien para curarse mejor

Artículo de divulgación publicado en The Conversation España el día 11/10/2022.Dormir lo suficiente es fundamental para gozar de salud. Pero ¿Qué ocurre cuando nos ingresan en un hospital y, además de estar ingresados, no podemos descansar bien? Hay evidencias científicas de que podemos tardar bastante más en curarnos o empeorar.N