Urine-derived cells from the aged donor for the 2D/3D modeling of neural cells via iPSCs.

Human neural cell models derived from induced pluripotent stem cells (iPSCs) have been widely accepted to model various neurodegenerative diseases such as Alzheimer's disease (AD) . Although the most common sources of iPSCs are fibroblasts and peripheral blood mononuclear cells, the collection of these cells is invasive. To reduce the donor's burden, we propose the use of urine-derived cells (UDCs), which can be obtained non-invasively from a urine sample. However, the collection of UDCs from elderly donors suffering from age-related diseases such as AD has not been reported, and it is unknown whether these UDCs from the donor aged over 80 years old can be converted into iPSCs and differentiated into neural cells. In this study, we reported a case of using the UDCs from the urine sample of an 89-year-old AD patient, and the UDCs were successfully reprogrammed into iPSCs and differentiated into neural cells in four different ways: (i) the dual SMAD inhibition with small-molecules via the neural progenitor precursor stage, (ii) the rapid induction method using transient expression of and microRNAs without going through the neural progenitor stage, (iii) the cortical brain organoids for 3D culture, and (iv) the human astrocytes. The accumulation of phosphorylated Tau proteins, which is a pathological hallmark of AD, was examined in the neuronal models generated from the UDCs of the aged donor. The application of this cell source will broaden the target population for disease modeling using iPS technology.