Cyclin-dependent kinase-5 targeting for ischaemic stroke.

Recovery from ischaemic stroke is dependent on survival of neurones, particularly in peri-infarcted regions. Angiogenesis is critical for the development of new microvessels resulting in the re-formation of collateral circulation associated with enhanced neuronal survival and reduced morbidity and mortality. Recently, the identification of a neurovascular niche has been described, where the co-ordinated effects of angiogenesis and migration of neuroprogenitor cells to damaged stroke regions were shown to be vital in the process of tissue remodelling. Cdk5, a serine/threonine kinase is highly expressed in the central nervous system, particularly following ischaemic stroke and its aberrant activation is directly associated with neuronal apoptosis and death. In contrast, recent evidence suggests that increased expression of Cdk5 by endothelium might be protective against cell death and/or promote angiogenesis leading to increased vessel formation and reperfusion. Owing to its known interaction with over 20 substrates including caspase-3, MEF2, Tau and p53, Cdk5 could be a master switch controlling both neuronal survival and revascularisation. Therefore its cell-specific pharmacological or genetic modulation using novel nanotechnology-based delivery systems could be of benefit when considering future stroke therapies.