RESUMO
The programmed cell death or apoptosis plays both physiological and pathological roles in biology. Anomalous activation of apoptosis has been associated with malignancies. The intrinsic mitochondrial pathway of apoptosis activation occurs through a multiprotein complex named the apoptosome. We have discovered molecules that bind to a central protein component of the apoptosome, Apaf-1, and inhibits its activity. These new first-in-class apoptosome inhibitors have been further improved by modifications directed to enhance their cellular penetration to yield compounds that decrease cell death, both in cellular models of apoptosis and in neonatal rat cardiomyocytes under hypoxic conditions.
Assuntos
Apoptose/efeitos dos fármacos , Apoptossomas/antagonistas & inibidores , Fator Apoptótico 1 Ativador de Proteases/antagonistas & inibidores , Peptoides/síntese química , Animais , Animais Recém-Nascidos , Apoptossomas/metabolismo , Proteínas de Transporte/química , Hipóxia Celular , Peptídeos Penetradores de Células , Células Cultivadas , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Conformação Molecular , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Fragmentos de Peptídeos/química , Peptoides/química , Peptoides/farmacologia , Ácido Poliglutâmico/química , Ligação Proteica , Ratos , Produtos do Gene tat do Vírus da Imunodeficiência Humana/químicaRESUMO
Apoptosis is a biological process relevant to human disease states that is strongly regulated through protein-protein complex formation. These complexes represent interesting points of chemical intervention for the development of molecules that could modulate cellular apoptosis. The apoptosome is a holoenzyme multiprotein complex formed by cytochrome c-activated Apaf-1 (apoptotic protease-activating factor), dATP and procaspase-9 that link mitochondria disfunction with activation of the effector caspases and in turn is of interest for the development of apoptotic modulators. In the present study we describe the identification of compounds that inhibit the apoptosome-mediated activation of procaspase-9 from the screening of a diversity-oriented chemical library. The active compounds rescued from the library were chemically optimised to obtain molecules that bind to both recombinant and human endogenous Apaf-1 in a cytochrome c-noncompetitive mechanism that inhibits the recruitment of procaspase-9 by the apoptosome. These newly identified Apaf-1 ligands decrease the apoptotic phenotype in mitochondrial-mediated models of cellular apoptosis.