Selective SERCA2a activator as a candidate for chronic heart failure therapy
Martina Arici, Shih-Che Hsu, Mara Ferrandi, Paolo Barassi, Carlotta Ronchi, Eleonora Torre, Andrea Luraghi, Gwo‐Jyh Chang, Paolo Ferrari, Giuseppe Bianchi, Francesco Peri, Antonio Zaza, Marcella Rocchetti
Abstract
Abstract Background The sarcoplasmic reticulum (SR) Ca 2+ ATPase (SERCA2a) depression substantially contributes to diastolic dysfunction in heart failure (HF), suggesting that SERCA2a stimulation may be a mechanism-based HF therapy. Istaroxime is a drug endowed with both a SERCA2a stimulatory activity and a Na + /K + pump inhibitory activity for acute HF treatment. Its main metabolite PST3093 shows a more favorable therapeutic profile as compared to the parent drug, but it is still unsuitable for chronic usage. Novel PST3093 derivatives have been recently developed for oral (chronic) HF treatment; compound 8 was selected among them and here characterized. Methods Effects of compound 8 were evaluated in a context of SERCA2a depression, by using streptozotocin-treated rats, a well-known model of diastolic dysfunction. The impact of SERCA2a stimulation by compound 8 was assessed at the cellular level ad in vivo, following i.v. infusion (acute effects) or oral administration (chronic effects). Results As expected from SERCA2a stimulation, compound 8 induced SR Ca 2+ compartmentalization in STZ myocytes. In-vivo echocardiographic analysis during i.v. infusion and after repeated oral administration of compound 8, detected a significant improvement of diastolic function. Moreover, compound 8 did not affect electrical activity of healthy guinea-pig myocytes, in line with the absence of off-target effects. Finally, compound 8 was well tolerated in mice with no evidence of acute toxicity. Conclusions The pharmacological evaluation of compound 8 indicates that it may be a safe and selective drug for a mechanism-based treatment of chronic HF by restoring SERCA2a activity. Graphical Abstract