Pizotifen Activates ERK and Provides Neuroprotection in vitro and in vivo in Models of Huntington's Disease.

BACKGROUND

Huntington's disease (HD) is a dominantly inherited neurodegenerative condition characterized by dysfunction in striatal and cortical neurons. There are currently no approved drugs known to slow the progression of HD.

OBJECTIVE

To facilitate the development of therapies for HD, we identified approved drugs that can ameliorate mutant huntingtin-induced toxicity in experimental models of HD.

METHODS

A chemical screen was performed in a mouse Hdh(Q111/Q111) striatal cell model of HD. This screen identified a set of structurally related approved drugs (pizotifen, cyproheptadine, and loxapine) that rescued cell death in this model. Pizotifen was subsequently evaluated in the R6/2 HD mouse model.

RESULTS

We found that in striatal Hdh(Q111/Q111) cells, pizotifen treatment caused transient ERK activation and inhibition of ERK activation prevented rescue of cell death in this model. In the R6/2 HD mouse model, treatment with pizotifen activated ERK in the striatum, reduced neurodegeneration and significantly enhanced motor performance.

CONCLUSIONS

These results suggest that pizotifen and related approved drugs may provide a basis for developing disease modifying therapeutic interventions for HD.