Novel Synthetic Coumarin-Chalcone Derivative (E)-3-(3-(4-(Dimethylamino)Phenyl)Acryloyl)-4-Hydroxy-2-Chromen-2-One Activates CREB-Mediated Neuroprotection in A and Tau Cell Models of Alzheimer's Disease.

Abnormal accumulations of misfolded A and tau proteins are major components of the hallmark plaques and neurofibrillary tangles in the brains of Alzheimer's disease (AD) patients. These abnormal protein deposits cause neurodegeneration through a number of proposed mechanisms, including downregulation of the cAMP-response-element (CRE) binding protein 1 (CREB) signaling pathway. Using CRE-GFP reporter cells, we investigated the effects of three coumarin-chalcone derivatives synthesized in our lab on CREB-mediated gene expression. A-GFP- and K280 tau-DsRed-expressing SH-SY5Y cells were used to evaluate these agents for possible antiaggregative, antioxidative, and neuroprotective effects. Blood-brain barrier (BBB) penetration was assessed by pharmacokinetic studies in mice. Of the three tested compounds, (E)-3-(3-(4-(dimethylamino)phenyl)acryloyl)-4-hydroxy-2-chromen-2-one (LM-021) was observed to increase CREB-mediated gene expression through protein kinase A (PKA), Ca/calmodulin-dependent protein kinase II (CaMKII), and extracellular signal-regulated kinase (ERK) in CRE-GFP reporter cells. LM-021 exhibited antiaggregative, antioxidative, and neuroprotective effects mediated by the upregulation of CREB phosphorylation and its downstream brain-derived neurotrophic factor and BCL2 apoptosis regulator genes in A-GFP- and K280 tau-DsRed-expressing SH-SY5Y cells. Blockage of the PKA, CaMKII, or ERK pathway counteracted the beneficial effects of LM-021. LM-021 also exhibited good BBB penetration ability, with brain to plasma ratio of 5.3%, in pharmacokinetic assessment. Our results indicate that LM-021 works as a CREB enhancer to reduce A and tau aggregation and provide neuroprotection. These findings suggest the therapeutic potential of LM-021 in treating AD.