Alzheimer’s disease (AD) is characterized by progressive neurodegeneration and cerebral accumulation of the β-amyloid peptide (Aβ), but it is unknown what makes neurons susceptible to degeneration. We report that the TGF-β type II receptor (TβRII) is mainly expressed by neurons, and that TβRII levels are reduced in human AD brain and correlate with pathological hallmarks of the disease. Reducing neuronal TGF-β signaling in mice resulted in age-dependent neurodegeneration and promoted Aβ accumulation and dendritic loss in a mouse model of AD. In cultured cells, reduced TGF-β signaling caused neuronal degeneration and resulted in increased levels of secreted Aβ and β-secretase–cleaved soluble amyloid precursor protein. These results show that reduced neuronal TGF-β signaling increases age-dependent neurodegeneration and AD-like disease in vivo. Increasing neuronal TGF-β signaling may thus reduce neurodegeneration and be beneficial in AD.
Ina Tesseur, Kun Zou, Luke Esposito, Frederique Bard, Elisabeth Berber, Judith Van Can, Amy H. Lin, Leslie Crews, Patrick Tremblay, Paul Mathews, Lennart Mucke, Eliezer Masliah, Tony Wyss-Coray