Associations between workload, myosin isoforms and performance on professional male basketball. A 4 seasons follow up

The aim of this study was to determine associations between workload, myosin isoforms, and performance in professional basketball, by following the progress of a professional basketball team over four consecutive seasons. Thirty male professional basketball players (age, 27.6 ± 4.1 years;height, 200.1 ± 9.4 cm;weight, 98.5 ± 12.6 kg) from an elite professional basketball team participated in this retrospective observational study. To analyze muscle response and which types of fiber were most involved, fast and myosin in serum were evaluated from three blood samples taken during the season, using enzyme-linked immunosorbent assay (ELISA). Parameters recorded were: exposure time,. Slow and fast myosins for muscle responses. Competitions won, ranking, and mean points scored for performance. Average values per season analysed were 280.1 ± 58 h of exposure to practice,1440.58±533.46µlmol/L of fast and 1178.75±427.75 µmol/L of slow myosin. Performance, assessed as team ranking was 6879.5 ± 985.37 u.a. per season and 90.72±2.79 u.a. per game, winning 7 competitions. Large negative relationships could be observed between slow myosins and exposure time (rho=−0.63;p=.02); There were possible associations between slow myosins and player mean performance per game (R2=0.98;p<.01) and team performance outcomes achieved (R2=0.83;p = 01) during these four seasons. Higher slow serum myosin values could be related to higher exposure time, and lower slow serum myosin values could be associated with better player and team performance. (AU)

Circulating irisin and glucose metabolism in overweight/obese women: effects of alpha-lipoic acid and eicosapentaenoic acid

Irisin is a myokine/adipokine with potential role in obesity and diabetes. The objectives of the present study were to analyse the relationship between irisin and glucose metabolism at baseline and during an oral glucose tolerance test (OGTT) and to determine the effects of eicosapentaenoic acid (EPA) and/or alpha-lipoic acid treatment on irisin production in cultured human adipocytes and in vivo in healthy overweight/obese women following a weight loss program. Seventy-three overweight/obese women followed a 30 % energy-restricted diet supplemented without (control) or with EPA (1.3 g/day), alpha-lipoic acid (0.3 g/day) or both EPA + alpha-lipoic acid (1.3 + 0.3 g/day) during 10 weeks. An OGTT was performed at baseline. Moreover, human adipocytes were treated with EPA (100–200 μM) or alpha-lipoic acid (100–250 μM) during 24 h. At baseline plasma, irisin circulating levels were positively associated with glucose levels; however, serum irisin concentrations were not affected by the increment in blood glucose or insulin during the OGTT. Treatment with alpha-lipoic acid (250 μM) upregulated Fndc5 messenger RNA (mRNA) and irisin secretion in cultured adipocytes. In overweight/obese women, irisin circulating levels decreased significantly after weight loss in all groups, while no additional differences were induced by EPA or alpha-lipoic acid supplementation. Moreover, plasma irisin levels were positively associated with higher glucose concentrations at beginning and at endpoint of the study. The data from the OGTT suggest that glucose is not a direct contributing factor of irisin release. The higher irisin levels observed in overweight/obese conditions could be a protective response of organism to early glucose impairments

Irisin is more strongly predicted by muscle oxidative potential than adiposity in non-diabetic men

Numerous controversies surround the peptide hormone irisin. Although implicated as a myokine promoting the browning of adipose tissue in rodents, its roles in humans remain unclear. Contradictory results have also been found with respect to the relationships between adiposity or metabolic health and plasma irisin levels in humans. We investigated the relationship between irisin levels and body composition (hydrostatic weighing), insulin sensitivity (hyperinsulinemic-euglycemic clamp), fitness level (ergocycle VO2max) and skeletal muscle metabolic profile in 53 men (aged 34–53 years) from four groups: sedentary non-obese controls (body mass index [BMI] <25 kg/m2), sedentary obese (BMI >30 kg/m2), sedentary obese glucose-intolerant, and non-obese highly trained endurance active. Baseline plasma irisin levels were significantly different between groups, being lowest in trained men (140.6 ± 38.2 ng/mL) and highest in metabolically deteriorated glucose-intolerant subjects (204.0 ± 50.5 ng/mL; ANOVA p = 0.01). Including all subjects, irisin levels were positively associated with adiposity (e.g. fat mass, r = 0.430, p < 0.01) and negatively associated with fitness (r = −0.369, p < 0.01), insulin sensitivity (M/I, r = −0.355, p < 0.01) and muscle citrate synthase (CS) activity (r = −0.482, p < 0.01). Most correlations lost statistical significance when excluding active individuals, except for insulin resistance (r = −0.413, p < 0.01) and CS (r = −0.462,p < 0.01). Multiple regression analyses reveal CS as the strongest independent predictor of irisin levels (r 2 range 0.214 to 0.237). We conclude that muscle oxidative potential is an important factor linked to circulating irisin levels

Frecuencia de polimorfismos del gen MYO9B en pacientes celiacos y en sujetos controles / Frequency of MYO9B polymorphisms in celiac patients and controls

Introducción: el gen miosina IX B (MYO9B) participa en el mantenimiento de la barrera intestinal y se postula que puede aportar riesgo para desarrollar enfermedad celiaca (EC). El objetivo de este estudio fue comparar la frecuencia y la asociación de los polimorfismos rs 2305764, rs 2305767 y rs 1457092 del gen MYO9B en pacientes pediátricos con EC procedentes de Chile y Argentina. Pacientes y métodos: el estudio se realizó en 104 pacientes pediátricos con EC (chilenos y argentinos) y en 104 sujetos controles. El análisis de los polimorfismos del gen MYO9B se realizó mediante ensayos Taqman de discriminación alélica. Se evalúo equilibrio de Hardy-Weinberg mediante Chi-cuadrado y comparación de haplotipos según prueba de Fisher. Resultados: los polimorfismos de un solo nucleótido (SNPs) rs2305767 y rs1457092 mostraron asociación con la EC. El genotipo TT del rs2305767 sería un factor protector (p < 0,0001, OR = 0,19 IC 0,1-0,4) mientras que el genotipo CT sería un factor de riesgo (p < 0,0001, OR = 4,9 IC 2,2-11,3). En el rs1457092, el genotipo CC resultó también un factor protector frente a esta enfermedad (p < 0,0001, OR = 0,07 IC 0,0-0,3). Conclusión: nuestros hallazgos sugieren que la variación genética del gen MYO9B estaría asociada a la EC en este grupo de pacientes, constituyendo un factor tanto de protección como a susceptibilidad dependiendo del polimorfismo en cuestión(AU)

Introduction: the MYO9B gene contributes to the maintenance of the intestinal barrier and it has been postulated as a risk factor of celiac disease (CD). The objective of this study was to compare the frequency and association rs2305764, rs2305767and rs1457092 MYO09B polymorphisms in pediatric CD patients from Chile and Argentina. Patients and methods: the study was made in 104 CD pediatric patients (Chilean and Argentineans) and 104 controls subjects. MYO9B gene polymorphisms were analyzed by Taqman allelic probes. We evaluated the Hardy-Weinberg equilibrium by means of Chisquare and compared the haplotypes distribution using Fisher test. Results: SNPs rs2305767 and rs1457092 were associated with celiac disease (CD); TT genotype in rs2305767 would be a protective factor (p < 0.000, OR = 0.19 CI 0.1-0.4) and the CT genotype would be a risk factor (p < 0.0001, OR = 4.9 CI 2.2 to 11.3). CC genotype in rs1457092 also showed a protective effect for celiac (p < 0.000, OR = 0.07 CI 0.0 to 0.3). Conclusion: our findings suggest that genetic variation MYO9B gene is associated with CD, as a protective or a risk factor depending on the polymorphism studied(AU)

Miocardiopatía hipertrófica de alto riesgo asociada con una nueva mutación en la proteína C fijadora de miosina / High-risk hypertrophic cardiomyopathy associated with a novel mutation in cardiac Myosin-binding protein C

La miocardiopatía hipertrófica (MCH) es una enfermedad genética de herencia autosómica dominante carac-terizada por incremento en la masa ventricular y desor-ganización miofibrilar. Se han identificado mutaciones causantes de MCH en 11 genes de proteínas del sarcómero cardiaco. La MCH causada por mutaciones en el gen de la proteína C fijadora de miosina (MYBPC3) tradicionalmente se ha considerado de curso benigno. Presentamos a una familia con varios miembros afectados de MCH y alta incidencia de muerte súbita, presumiblemente como consecuencia de la sustitución de citosina por guanina en el nucleótido 269 del ARNm del gen MYBPC3. Esta mutación, no descrita previamente, modifica el codón 79, que codifica la incorporación del aminoácido tirosina y da lugar a un codón de terminación. La mutación descrita parece conferir un riesgo mayor que el atribuido hasta el momento a la MCH secundaria a mutaciones en el gen MYBPC3

Hypertrophic cardiomyopathy is an autosomal dominant inherited disease characterized by ventricular hypertrophy and myofibril disarray. Mutations responsible for hypertrophic cardiomyopathy have been identified in 11 genes that encode for cardiac sarcomere proteins. Traditionally, hypertrophic cardiomyopathy due to mutation of the myosin-binding protein C gene (MYBPC3) has been thought to follow a benign course. We report a family with several members affected by hypertrophic cardiomyopathy in which there was a high incidence of sudden death. Disease was presumably caused by the substitution of cytosine by guanine at nucleotide 269 of MYBPC3 mRNA. This mutation, which has not previously been described, modifies codon 79, which encodes for the incorporation of a tyrosine, and gives rise to a stop codon. The mutation described here appears to confer a higher risk than that previously associated with hypertrophic cardiomyopathy due to MYBPC3 gene mutation

Modelos animales genéticamente modificados en investigación cardiovascular / Genetically Modified Animal Models in Cardiovascular Research

Es un principio básico de la medicina clínica y molecular que la función de las células y los órganos se basa en elementos proteicos específicos. Puesto que la función de las células y en último término de los órganos depende de los polipéptidos que se encuentran presentes, no es sorprendente que cuando se altera la función se produzcan cambios en el contenido de proteínas. En el corazón existen numerosos ejemplos en los que cambios en las proteínas contráctiles se correlacionan con alteraciones funcionales, tanto durante el desarrollo normal como durante el desarrollo de numerosas patologías. De la misma manera, diversas enfermedades cardíacas congénitas se caracterizan por determinados cambios en las proteínas motoras. Para comprender esta relación, y para establecer modelos en los que los procesos patogénicos puedan ser estudiados longitudinalmente, es necesario dirigir el corazón para que sintetice de manera estable la proteína candidata, en ausencia de otros cambios pleiotrópicos. Posteriormente, se puede determinar si la presencia de la proteína causa directa o indirectamente los efectos con el objetivo de definir potenciales dianas terapéuticas. Mediante la manipulación controlada de la dotación proteica del corazón, se puede establecer el mecanismo y la función de diferentes proteínas mutadas o isoformas proteicas. La reconstrucción génica y la transgénesis en el ratón proporcionan herramientas para modificar el genoma de los mamíferos y la dotación proteica motora del corazón. Dirigiendo la expresión de una proteína modificada por ingeniería genética directamente al corazón, es posible remodelar de manera efectiva el perfil proteico cardíaco y estudiar las consecuencias de una única manipulación genética a nivel molecular, bioquímico, citológico y fisiológico, tanto en condiciones normales como bajo estímulos de estrés (AU)