Targeting non-canonical p38 mapk signalling: discovery and characterization of novel allosteric p38α inhibitors
- Autores: Lorena González Velasco
- Directores de la Tesis: Ángel Rodríguez Nebreda (dir. tes.), Neus Agell Jané (tut. tes.)
- Lectura: En la Universitat de Barcelona ( España ) en 2021
- Idioma: inglés
- Tribunal Calificador de la Tesis: Florenci Serras Rigalt (presid.), Cristina Mayor Ruiz (secret.), Ricardo Biondi (voc.)
- Programa de doctorado: Programa de Doctorado en Biomedicina por la Universidad de Barcelona
- Materias:
- Texto completo no disponible (Saber más ...)
- Resumen
Non-canonical activation of p38α MAPK has been associated to cardiomyocyte death in several cardiovascular pathologies, such as myocardial ischaemia-reperfusion injury. Unfortunately, current p38α inhibitors are mainly ATP-competitors, which have not progressed in clinical trials.
Efforts to discover novel allosteric p38α inhibitors are crucial to overcome potential side effects that undermine their therapeutic efficacy. By running an in silico small molecule drug discovery program to target the non-canonical site on p38α, we have identified several compounds, named NC-p38i, which inhibit both TAB1-induced and spontaneous p38α autophosphorylation in vitro.
Additionally, NC-p38i do not inhibit canonical MAP2K-dependent p38α activation but slightly impair its ability to phosphorylate substrates. A combination of biophysical and structural studies has allowed us to characterize their mechanism of action. NC-p38i do not interfere with the binding of TAB1 to p38α in vitro but modulate the ATP-binding site and the prone-to-autophosphorylate conformation of the kinase. Nuclear magnetic resonance and X-ray crystallography data suggest that NC-p38i probably bind to several sites on p38α, including the active site and the N-terminal domain, which may induce structural rearrangements that reduce its autoactivation capacity. Cell based assays show that NC-p38i decrease ischaemiareperfusion-induced cardiomyocyte death both under prophylactic and therapeutic conditions.
Moreover, these compounds ameliorate doxorubicin-induced cardiac toxicity in human iPSCderived cardiomyocytes and zebrafish models. Importantly, NC-p38i are quite specific at inhibiting p38α but not a number of other protein kinases, and possess good drug-like properties, including weak cardiac hERG K+ channel inhibition and low cytotoxic effects.
Together, our data identify NC-p38i as novel allosteric p38α inhibitors with promising cardioprotective effects, which may serve as a good starting point to develop clinical candidates for treating non-canonical p38α signalling associated diseases.
