Release of growth factors by neuronal precursor cells as a treatment for diseases with tau pathology

The intraneuronal accumulation of the microtubule-associated protein tau in a hyperphosphorylated state and the extracellular deposit of β-amyloid protein constitute the defining neuropathological signature of Alzheimer's disease, the most common type of dementia in ageing Homo sapiens. There is accumulating evidence suggesting that transplantation of embryonic and adult-derived neuronal precursor cells (NPCs) has a major role for cell based repair strategies in models of acute and chronic injury. In order to determine whether NPCs could rescue tau-related neuronal cell death NPCs were transplanted into the cortex of transgenic mice expressing human P301S tau protein at 2 months of age and the effect followed 2 and 3 months after transplantation. The results demonstrated that following transplantation mouse NPCs differentiated into astrocytes and exerted a neuroprotective effect. In particular, the expression of ciliary neurotrophic factor and glial cell-derived neurotrophic factor was increased near the transplanted cells. A non-significant increase of brain-derived neurotrophic factor expression was instead found in the area of the cortex where neuronal death was rescued.