RESUMEN
Oxidative stress is a key concept in basic, translational, and clinical research to understand the pathophysiology of various disorders, including cardiovascular and renal diseases. Although attempts to directly reduce oxidative stress with redox-active substances have until now largely failed to prove clinical benefit, indirect approaches to combat oxidative stress enzymatically have gained further attention as potential therapeutic strategies. The pantetheinase Vanin-1 is expressed on kidney proximal tubular cells, and its reaction product cysteamine is described to negatively affect redox homeostasis by inhibiting the replenishment of cellular antioxidative glutathione stores. Vanin-1-deficient mice were shown to be protected against oxidative stress damage. The aim of this study was to elucidate whether pharmacological inhibition of Vanin-1 protects mice from oxidative stress-related acute or chronic kidney injury as well. By studying renal ischemia-reperfusion injury in Col4α3-/- (Alport syndrome) mice and in vitro hypoxia-reoxygenation in human proximal tubular cells we found that treatment with a selective and potent Vanin-1 inhibitor resulted in ample inhibition of enzymatic activity in vitro and in vivo. However, surrogate parameters of metabolic and redox homeostasis were only partially and insufficiently affected. Consequently, apoptosis and reactive oxygen species level in tubular cells as well as overall kidney function and fibrotic processes were not improved by Vanin-1 inhibition. We thus conclude that Vanin-1 functionality in the context of cardiovascular diseases needs further investigation and the biological relevance of pharmacological Vanin-1 inhibition for the treatment of kidney diseases remains to be proven.
Asunto(s)
Lesión Renal Aguda/prevención & control , Amidohidrolasas/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Túbulos Renales Proximales/efectos de los fármacos , Nefritis Hereditaria/prevención & control , Estrés Oxidativo/efectos de los fármacos , Insuficiencia Renal Crónica/prevención & control , Daño por Reperfusión/prevención & control , Lesión Renal Aguda/enzimología , Lesión Renal Aguda/genética , Lesión Renal Aguda/patología , Amidohidrolasas/genética , Amidohidrolasas/metabolismo , Animales , Apoptosis/efectos de los fármacos , Autoantígenos/genética , Autoantígenos/metabolismo , Línea Celular , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Modelos Animales de Enfermedad , Inhibidores Enzimáticos/farmacocinética , Fibrosis , Proteínas Ligadas a GPI/antagonistas & inhibidores , Proteínas Ligadas a GPI/genética , Proteínas Ligadas a GPI/metabolismo , Humanos , Túbulos Renales Proximales/enzimología , Túbulos Renales Proximales/patología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Nefritis Hereditaria/enzimología , Nefritis Hereditaria/genética , Nefritis Hereditaria/patología , Insuficiencia Renal Crónica/enzimología , Insuficiencia Renal Crónica/genética , Insuficiencia Renal Crónica/patología , Daño por Reperfusión/enzimología , Daño por Reperfusión/genética , Daño por Reperfusión/patologíaRESUMEN
Despite advances in the treatment of heart failure in recent years, options for patients are still limited and the disease is associated with considerable morbidity and mortality. Modulating cyclic guanosine monophosphate levels within the natriuretic peptide signaling pathway by inhibiting PDE9A has been associated with beneficial effects in preclinical heart failure models. We herein report the identification of BAY-7081, a potent, selective, and orally bioavailable PDE9A inhibitor with very good aqueous solubility starting from a high-throughput screening hit. Key aspect of the optimization was a switch in metabolism of our lead structures from glucuronidation to oxidation. The switch proved being essential for the identification of compounds with improved pharmacokinetic profiles. By studying a tool compound in a transverse aortic constriction mouse model, we were able to substantiate the relevance of PDE9A inhibition in heart diseases.