Serum levels of irisin and nesfatin-1 in multiple sclerosis / Níveis séricos de irisina e nesfatin-1 na esclerose múltipla

ABSTRACT Background: Multiple sclerosis (MS) is an inflammatory and neurodegenerative autoimmune chronic neurological disease. Currently, there are no effective serum biomarkers to verify MS diagnosis, to assess disease prognosis, and evaluate response to MS treatment. Objective: The present study is a preliminary assessment of irisin and nesfatin-1 serum levels in patients with relapsing- remitting MS (RRMS). Methods: A total of 86 participants, 42 patients with RRMS diagnosis and 44 healthy controls were included in the study. The serum irisin and nesfatin-1 parameters of the patients and control group members were analyzed. Results: Irisin and nesfatin-1 levels of the RRMS patients were significantly lower than the controls (z: -3.82, p<0.001; z: -4.79, p<0.001, respectively) The cut-off level of irisin is 10.390 (ng/mL) (sensitivity: 84.1%, specificity: 71.4%, AUC: 0.800), and the cut-off level of nestatin-1 is 7.155 (ng/mL) (sensitivity: 68.2%, specificity: 64.3%, AUC: 0.739) in the ROC analysis. For these cut-off levels in the case-control groups, the lower irisin and nesfatin-1 levels are the independent variables for MS patients (OR 9.723, 95%CI 2.884-32.785, p<0.001; OR 3.992, 95%CI 1.336-11.928, p<0.001) respectively. Conclusion: The present study revealed lower irisin and nesfatin-1 levels in patients with RRMS. These findings suggest that the decreased levels of irisin and nesfatin-1 peptides may contribute to MS pathogenesis such as inflammation, oxidative stress, and apoptosis in MS, leading to demyelination, axonal damage with neuronal loss, and gliosis.

RESUMO Antecedentes: A esclerose múltipla (EM) é uma doença neurológica crônica autoimune inflamatória e neurodegenerativa. Atualmente, não há biomarcadores séricos eficazes para verificar o diagnóstico de EM, para avaliar o prognóstico da doença e avaliar a resposta ao tratamento de EM. Objetivo: O presente estudo é uma avaliação preliminar dos níveis séricos de irisina e nesfatina-1 em pacientes com EM recorrente-remitente (EMRR). Métodos: Um total de 86 participantes, 42 pacientes com diagnóstico de EMRR e 44 controles saudáveis, foram incluídos no estudo. Os parâmetros séricos de irisina e nesfatina-1 dos pacientes e membros do grupo controle foram analisados. Resultados: Os níveis de irisina e nesfatina-1 dos pacientes com EMRR foram significativamente mais baixos do que os dos controles (z: -3,82, p <0,001; z: -4,79, p <0,001, respectivamente). O nível de corte de irisina é 10,390 (ng/mL) (sensibilidade: 84,1%, especificidade: 71,4%, AUC: 0,800), e o nível de corte de nestatina-1 é 7,155 (ng/mL) (sensibilidade: 68,2%, especificidade: 64,3%, AUC: 0,739) na análise ROC. Para esses níveis de corte nos grupos de caso-controle, os níveis mais baixos de irisina e nesfatina-1 são as variáveis independentes para pacientes com EM (OR 9,723, IC95% 2,884-32,785, p <0,001; OR 3,992, IC95% 1,336-11,928, p <0,001) respectivamente. Conclusão: O presente estudo revelou níveis mais baixos de irisina e nesfatina-1 em pacientes com EMRR. Esses achados sugerem que os níveis diminuídos de peptídeos irisina e nesfatina-1 podem contribuir para a patogênese da EM, como inflamação, estresse oxidativo e apoptose na EM, levando à desmielinização, dano axonal com perda neuronal e gliose.

The colors of adipose tissue and the relationship with irisin.

Excess adipose tissue is considered one of the main causes of metabolic and cardiovascular diseases. Initially, the adipose tissue was considered the main lipid and energy storage of the organism. Subsequently it was discovered that adipose tissue had other functions such as endocrine, controlling different metabolic and immune processes. Currently, different types of adipose tissue are recognized. The white adipocyte represents the main energy reserve, on the contrary the brown adipocyte is responsible for the oxidation of lipids for thermogenesis. The beige adipocyte originates from the white adipocyte, by a process known as "browning", which leads to lipolysis and thermogenesis. The 3 previous types have recently joined the blue adipocyte, which has a role in liver retinoid homeostasis and the pink adipocyte that participates in lactogenesis and is present in the mammary gland of animals; its role is still unknown in humans. The newly identified hormone Irisin is secreted by the skeletal muscle and promotes browning of white to beige adipose tissue, thus favoring thermogenesis. Another interesting aspect of this hormone is that it represents a connection between muscle activity and lipolysis. The above suggests that Irisin may be the key in the prevention and treatment of obesity.

El exceso de tejido adiposo representa una de las principales causas de las enfermedades metabólicas y cardiovasculares. Inicialmente al tejido adiposo se le consideró el almacén de lípidos y energía del organismo. Posteriormente se descubrió que presentaba otras funciones, como la endocrina, controlando diferentes procesos metabólicos e inmunitarios. Por sus características funcionales y estructurales, se reconocen varios tipos de tejido adiposo. El adipocito blanco representa la reserva energética y el adipocito marrón se encarga de la oxidación de los lípidos para la termogénesis. El adipocito beige se origina del adipocito blanco, mediante un proceso que conduce a la lipólisis y la termogénesis. A los anteriores se han sumado el adipocito azul, en el hígado, que interviene en la homeostasis de retinoides, y el adipocito rosa, que participa en la lactogénesis y se ha identificado en la glándula mamaria de animales. La irisina es una hormona secretada principalmente por el músculo esquelético, que promueve el pardeamiento del tejido adiposo blanco a beige, favoreciendo así la termogénesis. Otro aspecto interesante de esta hormona es que representa una conexión entre la actividad muscular y la lipólisis. Por lo anterior, la irisina puede ser una clave en la prevención y el tratamiento de la obesidad.

Aqueous humor heat-shock protein 70, periostin, and irisin levels in patients with pseudoexfoliation syndrome / Níveis de proteína de choque térmico 70, de periostina e de irisina no humor aquoso em pacientes com pseudoexfoliação

ABSTRACT Purpose: To measure humor heat-shock protein 70, periostin, and irisin levels in patients with pseudoexfoliation syndrome and cataract (without glaucoma), and compare them with those of patients with cataract but without pseudoexfoliation. Methods: We examined 31 eyes of 31 patients with pseudoexfoliation and cataract (without glaucoma) and 30 eyes of 30 patients with cataract. We collected aqueous humor samples from all patients at the time of cataract surgery through a limbal paracentesis via a 25-gauge cannula mounted on a tuberculin syringe that received 100 to 150 µL of aqueous humor. We measured levels of aqueous humor Heat shock protein 70, periostin, and irisin using enzyme-linked immunosorbent assay methods. Results: The age (p=0.221) and gender (p=0.530) means were similar between the pseudoexfoliation and control groups. The mean Heat shock protein 70 level (29.22 ± 9.46 ng/mL; 17.88-74.46) in the pseudoexfoliation group was significantly higher than that in the control group (19.03 ± 7.05 ng/mL; 9.93-35.52; p<0.0001). The mean periostin level was significantly higher (6017.32 ± 1271.79 pg/mL; 3787.50-10803.57) in the pseu doexfoliation group than that in the control group (4073.63 ± 1422.79 pg/mL; 2110.44-7490.64; p<0.0001). The mean irisin level (53.77 ± 10.19 ng/mL; 29.46-71.16) was significantly higher than that in the control group (39.29 ± 13.58 ng/mL; 19.41-70.56; p<0.0001). Conclusions: Heat shock protein 70, periostin, and irisin levels increase in the aqueous humor of patients with pseudoexfoliation without glaucoma.

RESUMO Objetivo: Comparar os níveis de proteína de choque térmico 70, de periostina e de irisina no humor aquoso de pacientes com pseudoexfoliação com catarata sem glaucoma e compará-los com pacientes com catarata sem pseudoexfoliação. Métodos: Trinta e um olhos de 31 pacientes com pseudoexfoliação com catarata sem glaucoma e 30 olhos de 30 indivíduos com catarata foram incluídos neste estudo. Amostras de humor aquoso foram coletadas de todos os pacientes no momento da cirurgia de catarata e obtidas através de uma paracentese límbica por meio de uma cânula de calibre 25 acoplada a uma seringa com tuberculina. Foram coletados 100 a 150 µL de humor aquoso. Os níveis de proteína de choque térmico 70, de periostina e de irisina no humor aquoso foram medidos usando o método de ensaio imunossorvente ligado a enzima. Resultados: A média da idade (p=0,221) e sexo (p=0,530) foram semelhantes entre os grupos pseudoexfoliação e controle. Os níveis médios de proteína de choque térmico 70 foram 29,22 ± 9,46 ng/mL (17,88-74,46) e 19,03 ± 7,05 ng/ mL (9,93-35,52) nos grupos pseudoexfoliação e controle, respectivamente. Os níveis de proteína de choque térmico 70 foram maiores no grupo pseudoexfoliação (p<0,0001). O nível médio de periostina foi de 6017,32 ± 1271,79 pg/mL (3787,50-10803,57) no grupo pseudoexfoliação e 4073,63 ± 1422,79 pg/mL (2110,44-7490,64) no grupo controle. O nível médio de periostina também foi maior no grupo pseudoexfoliação (p<0,0001). Os níveis médios de irisina foram 53,77 ± 10,19 ng/mL (29,46-71,16) e 39,29 ± 13,58 ng/mL (19,41-70,56) nos grupos pseudoexfoliação e controle, respectivamente. O nível médio de irisina foi maior no grupo pseudoexfoliação do que no grupo controle (p<0,0001). Conclusões: Os níveis de proteína de choque térmico 70, de periostina e de irisina aumentam no humor aquoso de pacientes com pseudoexfoliação sem glaucoma.

Serum levels of the adipomyokine irisin in patients with chronic kidney disease. / Niveles séricos de la adipomioquina irisina en pacientes con enfermedad renal crónica.

BACKGROUND: Irisin is an adipomyokine with claimed anti-obesity and anti-diabetic effects. This hormone has been insufficiently studied in patients with advanced chronic kidney disease (CKD). OBJECTIVE: To perform an exploratory analysis of serum irisin levels in patients undergoing different CKD treatments. METHOD: Following a cross-sectional design, we estimated serum levels of irisin in 95 patients with CKD managed conservatively (advanced CKD), with peritoneal dialysis (PD) or with haemodialysis, and compared our findings with a control group of 40 healthy individuals. We investigated the correlations between serum irisin and demographic, clinical, body composition and metabolic variables. RESULTS: Irisin levels were lower in all the CKD groups than in the control group. The univariate analysis revealed limited correlations between irisin, on the one hand, and fat (but not lean) mass, glomerular filtration rate (GFR) and plasma albumin and bicarbonate, on the other. The multivariate analysis confirmed that advanced CKD patients managed conservatively (difference 111.1ng/ml), with PD (25.9ng/ml) or haemodialysis (61.4ng/ml) (all P<.0005) presented lower irisin levels than the control group. Furthermore, PD patients presented higher serum levels of irisin than those on haemodialysis (difference 39.4ng/ml, P=.002) or those managed conservatively (24.4 ng/ml, P=.036). The multivariate analysis also identified plasma bicarbonate (B=3.90 per mM/l, P=.001) and GFR (B=1.89 per ml/minute, P=.003) as independent predictors of irisin levels. Conversely, no adjusted correlation between irisin and body composition markers was found. CONCLUSIONS: Serum irisin levels are low in patients with CKD and show a consistent correlation with GFR and plasma bicarbonate levels. PD patients present higher levels of irisin than those managed conservatively or with haemodialysis. Our study confirms a general inconsistency of the association between serum irisin levels, on the one hand, and body composition and metabolic markers, on the other.

Actualizaciones sobre "Irisina": la nueva mioquina / Irisin updates: the new myokine

In the continuous search of researchers to find an effective method to control obesity, a myokine called Irisin was found. Irisin is secreted mainly by skeletal muscle in response to exercise, either resistance, strength or high intensity, where High Intensity Interval Training (HIIT) is included. This polypeptide hormone acts mainly on subcutaneous adipose cells, turning white fat into brown fat. Brown fat is highly thermogenic, which enhance raising of total energy expenditure and helps maintaining or loosing corporal weight. Plasmatic Irisin levels are related positively with insulin sensitivity and weight loss. It has been also discovered that a greater plasmatic level of Irisin is related to the lengthening of telomeres, to a greater concentration of free tyrosine (T4) and it has been recently found that is related to an antitumoral effect on some types of cancer. All of the functions mediated by Irisin, have given it a protective action against different diseases, especially metabolic ones. The aim of this review was to update the knowledge about Irisin, and to show the effects that exercise has on its plasmatic levels, as well as comprehend how does the release of irisin influences different body systems. Counting with more information will allow the arising of new lines of investigation that will bring up non pharmacological therapeutic strategies for the treatment of non-communicable diseases.

En la búsqueda continua de los investigadores por combatir de manera más efectiva la obesidad, se descubre una mioquina llamada Irisina. La Irisina es secretada principalmente por el músculo esquelético en respuesta al ejercicio, ya sea aeróbico, de fuerza o de alta intensidad, donde se incluyen, ejercicios de intervalo de alta intensidad (HIIT). Esta hormona polipeptídica actúa principalmente sobre células adiposas subcutáneas, transformando grasa blanca en grasa parda. La grasa parda es altamente termogénica, lo que favorece el aumento del gasto energético total y ayuda a mantener o incluso a perder peso corporal. La concentración de Irisina plasmática se relaciona positivamente con la sensibilidad a la insulina y la pérdida de peso. Además, se ha descubierto que una mayor concentración de Irisina plasmática se relaciona con el alargamiento de los telómeros, y también, con una mayor concentración de T4 libre y con un recién descubierto efecto antitumoral en algunos tipos de cáncer. Todas las funciones mediadas por la Irisina, le atribuyen una acción protectora contra distintas enfermedades, especialmente metabólicas. El objetivo de esta revisión fue actualizar el conocimiento sobre la Irisina, evidenciando los efectos que tiene la realización de ejercicio sobre los niveles plasmáticos de ésta, así como también comprender como su liberación influye en distintos sistemas corporales. El contar con mayor información dará paso a nuevas líneas de investigación y permitirá contar con estrategias terapéuticas no farmacológicas que contribuyan en el tratamiento de enfermedades crónicas no transmisibles.

[Irisin: a messenger from the gods?]. / Irisina: ¿transmisor de mensajes del Olimpo?

Due to the need to understand the basis of the metabolic benefits of exercise, irisin was discovered a few years ago. This cytokine, secreted by skeletal muscle due to exercise, should have positive effects on energetic metabolism. In particular, it could act as a messenger on white adipose tissue, modifying its phenotype into the beige adipocyte, and increasing its thermogenic capacity. Since it was described, there have been numerous studies led to depict its function, with the aim of determining if irisin could become a therapeutic target in the context of diseases associated with a caloric excess, such as obesity and diabetes. In this review, the irisin discovery is summarized, along with its in vitro and in vivo effects described up until now.