A novel approach to Alzheimer’s Disease treatment: HDACs & PDE5 inhibition

Considering the numerous complex and different pathological mechanisms involved in Alzheimer´s disease (AD) progression, treatments targeting a single cause may lead to limited benefits. The goal of this study was the identification of a novel mode of action for this unmet need. Pharmacological tool compounds: suberoylanilide hydroxamic acid (SAHA) and tadalafil, targeting histone deacetylases (HDAC) and phosphodiesterase 5 (PDE5) respectively, were utilized simultaneously for in-vitro and in-vivo Proof-of-Concept (PoC). A synergistic effect was observed in the amelioration of AD signs using the combination therapy in Tg2576 mice. Finally, a therapeutic agent, CM-414, inhibiting simultaneously HDAC2/6 and PDE5 was generated and tested in Tg2576 mice. CM-414 reversed cognitive impairment, reduced amyloid and tau pathology, and rescued dendritic spine density loss in the hippocampus in AD mice. Importantly, the effect obtained was present after a 4-weeks wash-out period. Comparisson of global gene expression profiling in mice hippocampi between diferent treatments