β-alanine supplementation improves in-vivo fresh and fatigued skeletal muscle relaxation speed

Purpose: In fresh muscle, supplementation with the rate-limiting precursor of carnosine, β-alanine (BA), results in a decline in muscle half-relaxation time (HRT) potentially via alterations to calcium (Ca2+) handling. Accumulation of hydrogen cation (H+) has been shown to impact Ca2+ signalling during muscular contraction, carnosine has the potential to serve as a cytoplasmic regulator of Ca2+ and H+ coupling, since it binds to both ions. The present study examined the effect of BA supplementation on intrinsic in-vivo isometric knee extensor force production and muscle contractility in both fresh and fatigued human skeletal muscle assessed during voluntary and electrically evoked (nerve and superficial muscle stimulation) contractions. Methods: Twenty-three males completed two experimental sessions, pre- and post- 28 day supplementation with 6.4 g.day−1 of BA (n=12) or placebo (PLA; n=11). Isometric force was recorded during a series of voluntary and electrically evoked knee extensor contractions. Results: BA supplementation had no effect on voluntary or electrically  evoked isometric force production, or twitch electromechanical delay and time-to-peak tension. There was a significant decline in muscle HRT in fresh and fatigued muscle conditions  during both resting (3±13%; 19±26%) and potentiated (1±15%; 2±20%) twitch contractions. Conclusions: The mechanism for reduced HRT in fresh and fatigued skeletal muscle following BA supplementation is unclear. Due to the importance of muscle relaxation on total energy consumption, especially during short, repeated contractions, BA supplementation may prove to be beneficial in minimising contractile slowing induced by fatigue. Trial registration The trial is registered with Clinicaltrials.gov, ID number NCT02819505

Sequencing, de novo annotation and analysis of the first Anguilla anguilla transcriptome: EeelBase opens new perspectives for the study of the critically endangered european eel

Background: Once highly abundant, the European eel (Anguilla anguilla L.; Anguillidae; Teleostei) is considered to be critically endangered and on the verge of extinction, as the stock has declined by 90-99% since the 1980s. Yet, the species is poorly characterized at molecular level with little sequence information available in public databases.\ud \ud Results: The first European eel transcriptome was obtained by 454 FLX Titanium sequencing of a normalized cDNA library, produced from a pool of 18 glass eels (juveniles) from the French Atlantic coast and two sites in the Mediterranean coast. Over 310,000 reads were assembled in a total of 19,631 transcribed contigs, with an average length of 531 nucleotides. Overall 36% of the contigs were annotated to known protein/nucleotide sequences and 35 putative miRNA identified.\ud \ud Conclusions: This study represents the first transcriptome analysis for a critically endangered species. EeelBase, a dedicated database of annotated transcriptome sequences of the European eel is freely available at http://compgen.bio.unipd.it/eeelbase. Considering the multiple factors potentially involved in the decline of the European eel, including anthropogenic factors such as pollution and human-introduced diseases, our results will provide a rich source of data to discover and identify new genes, characterize gene expression, as well as for identification of genetic markers scattered across the genome to be used in various applications

Global Metabolomic Profiling of Acute Myocarditis Caused by Trypanosoma cruzi Infection

© 2014 Gironès et al. Chagas disease is caused by Trypanosoma cruzi infection, being cardiomyopathy the more frequent manifestation. New chemotherapeutic drugs are needed but there are no good biomarkers for monitoring treatment efficacy. There is growing evidence linking immune response and metabolism in inflammatory processes and specifically in Chagas disease. Thus, some metabolites are able to enhance and/or inhibit the immune response. Metabolite levels found in the host during an ongoing infection could provide valuable information on the pathogenesis and/or identify deregulated metabolic pathway that can be potential candidates for treatment and being potential specific biomarkers of the disease. To gain more insight into those aspects in Chagas disease, we performed an unprecedented metabolomic analysis in heart and plasma of mice infected with T. cruzi. Many metabolic pathways were profoundly affected by T. cruzi infection, such as glucose uptake, sorbitol pathway, fatty acid and phospholipid synthesis that were increased in heart tissue but decreased in plasma. Tricarboxylic acid cycle was decreased in heart tissue and plasma whereas reactive oxygen species production and uric acid formation were also deeply increased in infected hearts suggesting a stressful condition in the heart. While specific metabolites allantoin, kynurenine and p-cresol sulfate, resulting from nucleotide, tryptophan and phenylalanine/tyrosine metabolism, respectively, were increased in heart tissue and also in plasma. These results provide new valuable information on the pathogenesis of acute Chagas disease, unravel several new metabolic pathways susceptible of clinical management and identify metabolites useful as potential specific biomarkers for monitoring treatment and clinical severity in patients.This work was supported by ‘‘Ministerio de Ciencia e Innovación’’ (SAF2010-17833); ‘‘Fondo de Investigaciones Sanitarias’’ (PS09/00538 and PI12/00289); ‘‘Red de Investigación de Centros de Enfermedades Tropicales’’ (RICET RD12/0018/0004); European Union (HEALTH-FE-2008-22303, ChagasEpiNet);‘‘Universidad Autónoma de Madrid’’ and ‘‘Comunidad de Madrid’’ (CC08-UAM/SAL-4440/08); AECID Cooperation with Argentine (A/025417/09 and A/031735/10), Comunidad de Madrid (S-2010/BMD-2332) and ‘‘Fundación Ramón Areces’Peer Reviewe

Genetic variation in Wnt/β-catenin and ER signalling pathways in female and male elite dancers and its associations with low bone mineral density: a cross-section and longitudinal study.

The association of genetic polymorphisms with low bone mineral density in elite athletes have not been considered previously. The present study found that bone mass phenotypes in elite and pre-elite dancers are related to genetic variants at the Wnt/β-catenin and ER pathways. Some athletes (e.g. gymnasts, dancers, swimmers) are at increased risk for low bone mineral density (BMD) which, if untreated, can lead to osteoporosis. To investigate the association of genetic polymorphisms in the oestrogen receptor (ER) and the Wnt/β-catenin signalling pathways with low BMD in elite and pre-elite dancers (impact sport athletes). The study included three phases: (1) 151 elite and pre-elite dancers were screened for the presence of low BMD and traditional osteoporosis risk factors (low body weight, menstrual disturbances, low energy availability); (2) a genetic association study was conducted in 151 elite and pre-elite dancers and age- and sex- controls; (3) serum sclerostin was measured in 101 pre-elite dancers and age- and sex-matched controls within a 3-year period. Eighty dancers revealed low BMD: 56.3% had at least one traditional osteoporosis risk factor, whereas 28.6% did not display any risk factor (37.2% revealed traditional osteoporosis risk factors, but had normal BMD). Body weight, menstrual disturbances and energy availability did not fully predict bone mass acquisition. Instead, genetic polymorphisms in the ER and Wnt/β-catenin pathways were found to be risk factors for low BMD in elite dancers. Sclerostin was significantly increased in dancers compared to controls during the 3-year follow-up (p < 0.05)