Adeno-associated virus-mediated inhibition of ROCK2 promotes synaptogenesis and neurogenesis in rats after ischemic stroke

Abstract Neurite outgrowth and synaptogenesis are critical steps for functional recovery following ischemic stroke. Damaged axons of the central nervous system in adult mammals exhibit limited regenerative capacity, resulting in enduring neurological deficits. Recent findings from our research indicate that inhibition of Rhoassociated kinase (ROCK)2 facilitates neuroprotection in different models of central nervous system diseases. In addition, our prior studies have demonstrated that axonal protection enhances the regeneration of injured axons. However, it remains unclear whether the axonal protection mediated by ROCK2 inhibition also facilitates synaptogenesis. In this study, we aimed to investigate the effects of inhibiting ROCK2 expression on synaptogenesis and neurogenesis in ischemic stroke using an shRNA-expressing adeno-associated virus (AAV) vector (AAV-sh.ROCK2). We demonstrated that AAV-sh.ROCK2 increased neurite outgrowth and facilitated synaptogenesis in vivo . Furthermore, AAV-sh.ROCK2 increased neuronal survival and promoted neurogenesis following middle cerebral artery occlusion surgery as well as long-term motor functional recovery after ischemia/reperfusion injury. Notably, AAV-sh.ROCK2 also stimulated serotonergic and dopaminergic axon sprouting after ischemia/reperfusion injury. Mechanistically, AAV-sh.ROCK2 activity resulted in increased anti-collapsin response mediator protein 2 activation and reductions in RhoA and ROCK2 expression. Our study identified ROCK2 as a critical regulator of synaptogenesis and neurogenesis, highlighting it as a promising target to facilitate neuroprotection and regeneration in ischemic stroke.