A New Cell Model Overexpressing sTGFBR3 for Studying Alzheimer's Disease In vitro.

BACKGROUND: Recent studies have suggested that abnormal microglial hyperactivation has an important role in the progression of Alzheimer's disease (AD). sTGFBR3 (a shed extracellular domain of the transforming growth factor type III receptor) is a newly identified target of microglia polarization dysregulation, whose overexpression can cause abnormal accumulation of transforming growth factor ß1 (TGF-ß1), promoting Aß, tau, and neuroinflammatory pathology. OBJECTIVE: The objective of this study is to develop and validate a new cell model overexpressing sTGFBR3 for studying AD in vitro. METHODS: BV2 cells (a microglial cell derived from C57/BL6 murine) were used as a cell model. Cells were then treated with different concentrations of lipopolysaccharide (LPS) (0, 1, or 0.3 µg/mL) for 12, 24, or 48h and then with or without sodium pervanadate (100 µM) for 30 min. Next, the effect surface optimization method was used to determine optimal experimental conditions. Finally, the optimized model was used to assess the effect of ZQX series compounds and vasicine on cell viability and protein expression. Expression of TGFBR3 and TNF-α was assessed using Western blot. MTT assay was used to assess cell viability, and enzyme- linked immunosorbent assay (ELISA) was employed to evaluate extracellular TGF-ß1 and sTGFBR3. RESULTS: LPS (0.3 µg/mL) treatment for 11 h at a cell density of 60% and pervanadate concentration (100 µM) incubation for 30 min were the optimal experimental conditions for increasing membrane protein TGFBR3 overexpression, as well as extracellular sTGFBR3 and TGF-ß1. Applying ZQX-5 and vasicine reversed this process by reducing extracellular TGF-ß1, promoting the phosphorylation of Smad2/3, a protein downstream of TGF-ß1, and inhibiting the release of the inflammatory factor TNF-α. CONCLUSION: This new in vitro model may be a useful cell model for studying Alzheimer's disease in vitro.

An inhibitor with GSK3ß and DYRK1A dual inhibitory properties reduces Tau hyperphosphorylation and ameliorates disease in models of Alzheimer's disease.

Since Alzheimer's disease (AD) is a complex and multifactorial neuropathology, the discovery of multi-targeted inhibitors has gradually demonstrated greater therapeutic potential. Neurofibrillary tangles (NFTs), the main neuropathologic hallmarks of AD, are mainly associated with hyperphosphorylation of the microtubule-associated protein Tau. The overexpression of GSK3ß and DYRK1A has been recognized as an important contributor to hyperphosphorylation of Tau, leading to the strategy of using dual-targets inhibitors for the treatment of this disorder. ZDWX-12 and ZDWX-25, as harmine derivatives, were found good inhibition on dual targets in our previous study. Here, we firstly evaluated the inhibition effect of Tau hyperphosphorylation using two compounds by HEK293-Tau P301L cell-based model and okadaic acid (OKA)-induced mouse model. We found that ZDWX-25 was more effective than ZDWX-12. Then, based on comprehensively investigations on ZDWX-25 in vitro and in vivo, 1) the capability of ZDWX-25 to show a reduction in phosphorylation of multiple Tau epitopes in OKA-induced neurodegeneration cell models, and 2) the effect of reduction on NFTs by 3xTg-AD mouse model under administration of ZDWX-25, an orally bioavailable, brain-penetrant dual-targets inhibitor with low toxicity. Our data highlight that ZDWX-25 is a promising drug for treating AD.