Receptor-Interacting Protein 3/Calmodulin-Dependent Kinase II/Proline-Rich Tyrosine Kinase 2 Pathway is Involved in Programmed Cell Death in a Mouse Model of Brain Ischaemic Stroke

Abstract

Neuronal necroptosis and apoptosis are the most important pathways for programmed cell death after brain ischaemic stroke. Although apoptosis signalling pathways have been extensively studied, molecular mechanisms underlying necroptosis remain unclear. In this study, we found that receptor-interacting protein 3 (RIP3) deficiency reduced cerebral infarction volume, neurological deficits, and neuronal ultrastructural damage in a mouse model of brain ischaemic stroke by inhibiting programmed cell death. RIP3 deficiency inhibited the activation of both calmodulin-dependent kinase II (CaMKII) and proline-rich tyrosine kinase 2 (Pyk2) cascade, decreased the expression of classic necroptotic and apoptotic proteins, and ultimately decreased neuronal necroptosis and apoptosis. We further confirmed that RIP3 deficiency inhibited the decrease of mitochondrial membrane potential, the increase of calcium influx and reactive oxygen species (ROS) production. In addition, compared with WT primary cortical neurons, the decreased expression of CaMKII and Pyk2 was further verified in a Ripk3^-/- primary cortical neurons underlying oxygen and glucose deprivation/reoxygenation (OGD/R) model. In conclusion, we first identified that the RIP3/CaMKII/Pyk2 pathway is involved in programmed cell death after brain ischaemic stroke, which suggests it is a promising therapeutic target in ischaemia-induced neuronal injury.

Keywords: apoptosis; calmodulin-dependent kinase II; ischaemic stroke; necroptosis; proline-rich tyrosine kinase 2; receptor-interacting protein 3.