The dynamics of cellular injury: transformation into neuronal and vascular protection.

Despite the immediate event, such as cerebral trauma, cardiac arrest, or stroke that may result in neuronal or vascular injury, specific cellular signal transduction pathways in the central nervous system ultimately influence the extent of cellular injury. Yet, it is a cascade of mechanisms, rather than a single cellular pathway, which determine cellular survival during toxic insults. Although neuronal injury associated with several disease entities, such as Alzheimer's disease, Parkinson's disease, and cerebrovascular disease was initially believed to be irreversible, it has become increasingly evident that either acute or chronic modulation of the cellular and molecular environment within the brain can prevent or even reverse cellular injury. In order to develop rational, efficacious, and safe therapy against neurodegenerative disorders, it becomes vital to elucidate the cellular and molecular mechanisms that control neuronal and vascular injury. These include the pathways of free radical injury, the independent mechanisms of programmed cell death, and the downstream signal transduction pathways of endonuclease activation, intracellular pH, cysteine proteases, the cell cycle, and tyrosine phosphatase activity. Employing the knowledge gained from investigations into these pathways will hopefully further efforts to successfully develop effective treatments against central nervous system disorders.