17 resultados para heart right ventricle failure
Resumo:
In winning the municipal elections of March 2014, France’s mainstream opposition – the Centrists and the Union pour un Mouvement Populaire (UMP) – benefited not only from the unpopularity of the Left in power, but also from its own (partial) reconstruction. The Centrists had reorganised; the UMP had reaffirmed its right-wing programme and drawn strength from the opposition social movements launched in 2013. The European elections of 2014, however, demonstrated the limitations of this reconstruction. Their weak institutionalisation – the original sin of France’s Right and centre-Right – left internal ideological differences and (above all) personal rivalries unchecked within both forces. These tensions were compounded, in the UMP, by a series of financial scandals. At their heart was former president Nicolas Sarkozy, still the activists’ darling, ever more clearly a candidate for 2017, but also more hobbled by judicial investigations.
Resumo:
Impaired mechanosensing leads to heart failure and we have previously shown that a decreased ratio of cytoplasmic to nuclear CSRP3/Muscle LIM protein (MLP ratio) is associated with a loss of mechanosensitivity. Here we tested whether passive or active stress/strain was important in modulating the MLP ratio and determined whether this correlated with heart function during the transition to failure. We exposed cultured neonatal rat myocytes to 10% cyclic mechanical stretch at 1 Hz, or electrically paced myocytes at 6.8 V (1 Hz) for 48 h. The MLP ratio decreased 50% (P < 0.05, n = 4) only in response to electrical pacing, suggesting impaired mechanosensitivity. Inhibition of contractility with 10 μM blebbistatin resulted in a ∼3 fold increase in the MLP ratio (n = 8, P < 0.05), indicating that myocyte contractility regulates nuclear MLP. Inhibition of histone deacetylase (HDAC) signaling with trichostatin A increased nuclear MLP following passive stretch, suggesting that HDACs block MLP nuclear accumulation. Inhibition of heme-oxygenase1 (HO-1) activity with PPZII blocked MLP nuclear accumulation. To examine how mechanosensitivity changes during the transition to heart failure, we studied a guinea pig model of angiotensin II infusion (400 ng/kg/min) over 12 weeks. Using subcellular fractionation we showed that the MLP ratio increased 88% (n = 4, P < 0.01) during compensated hypertrophy, but decreased significantly during heart failure (P < 0.001, n = 4). The MLP ratio correlated significantly with the E/A ratio (r = 0.71, P < 0.01 n = 12), a clinical measure of diastolic function. These data indicate for the first time that myocyte mechanosensitivity as indicated by the MLP ratio is regulated primarily by myocyte contractility via HO-1 and HDAC signaling.