Genomics & Genetics Weekly via NewsEdge :

2008 MAY 9 - (NewsRx.com) -- Scientists discuss in 'The adenosine kinase hypothesis of epileptogenesis' new findings in epilepsy (see also Epilepsy Therapy). According to recent research from the United States, "Current therapies for epilepsy are largely symptomatic and do not affect the underlying mechanisms of disease progression, i.e. epileptogenesis. Given the large percentage of pharmacoresistant chronic epilepsies, novel approaches are needed to understand and modify the underlying pathogenetic mechanisms."

"Although different types of brain injury (e.g. status epilepticus, traumatic brain injury, stroke) can trigger epileptogenesis, astrogliosis appears to be a homotypic response and hallmark of epilepsy. Indeed, recent findings indicate that epilepsy might be a disease of astrocyte dysfunction. This review focuses on the inhibitory neuromodulator and endogenous anticonvulsant adenosine, which is largely regulated by astrocytes and its key metabolic enzyme adenosine kinase (ADK). Recent findings support the 'ADK hypothesis of epileptogenesis': (i) Mouse models of epileptogenesis suggest a sequence of events leading from initial downregulation of ADK and elevation of ambient adenosine as an acute protective response, to changes in astrocytic adenosine receptor expression, to astrocyte proliferation and hypertrophy (i.e. astrogliosis), to consequential overexpression of ADK, reduced adenosine and -finally -to spontaneous focal seizure activity restricted to regions of astrogliotic overexpression of ADK. (ii) Transgenic mice overexpressing ADK display increased sensitivity to brain injury and seizures. (iii) Inhibition of ADK prevents seizures in a mouse model of pharmacoresistant epilepsy. (iv) Intrahippocampal implants of stem cells engineered to lack ADK prevent epileptogenesis," wrote D. Boison and colleagues, .

The researchers concluded: "Thus, ADK emerges both as a diagnostic marker to predict, as well as a prime therapeutic target to prevent, epileptogenesis."

Boison and colleagues published their study in Progress In Neurobiology (The adenosine kinase hypothesis of epileptogenesis. Progress In Neurobiology, 2008;84(3):249-62).

For additional information, contact D. Boison, RS Dow Neurobiology Laboratories, Legacy Research, Portland OR 97232 USA..

Publisher contact information for the journal Progress In Neurobiology is: Pergamon-Elsevier Science Ltd., the Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, England.

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