Curtin BF, Pal N, Gordon RK, Nambiar MP.Forskolin, an
inducer of cAMP, up-regulates acetylcholinesterase expression
and protects against organophosphate exposure in neuro 2A cells.
Mol Cell Biochem. 2006 Aug 19
Department of Biochemical Pharmacology, Division of
Biochemistry, Walter Reed Army Institute of Research, 503 Robert
Grant Avenue, Silver Spring, MD 20910-7500, USA.
Bioscavenger prophylactic therapy using purified human
acetylcholinesterase (AChE) or butylcholinesterase (BChE) is a
promising treatment for future protection against chemical
warfare nerve agent exposure. Potential immune response due to
the complex structure of cholinesterases, mutations,
post-translational modifications, and genetic variation is a
limiting factor against purified enzyme therapy. We investigated
an alternative bioscavenger approach using forskolin, an inducer
of intracellular cyclic AMP (cAMP), which activates AChE
promoter and up-regulates its expression. A mouse neuronal cell
line, Neuro 2A, was treated with various doses of forskolin and
analysis of the expressed enzyme indicates that the AChE
activity was significantly increased in cells exposed to
repeated administration of the drug every other day for 7-10
days. Cholinesterase enzyme assays showed that the enzyme
activity was increased approximately 2-fold for the
extracellular enzyme and 3-fold for the intracellular enzyme.
The optimal dose found for extracellular enzyme production was
12-24 microM forskolin, while the optimal dose for intracellular
was 12 microM. In parallel with the rise in the AChE level, the
morphology of forskolin-treated cells showed neurite growth with
increasing doses. Forskolin treatment protects Neuro 2A cells
from diisopropylflurophophate (DFP), a surrogate of the
organophosphate chemical warfare agents soman and sarin, induced
toxicity in Neuro 2A cells. These results indicate that
transcriptional inducers, such as forskolin, can sufficiently
up-regulate cellular AChE production and protect cells against
organophosphate toxicity.
PMID: 16924422
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