Brain and muscle cells have turned up in kidney organoids, scientists report from an analysis of their own material. While 80 percent to 90 percent of the cells in mini-organs they grew were kidney cells, the appearance of the interlopers suggests that the organoid recipe—including drugs and growth factors to coax stem cells to differentiate into kidney cells—also spurs the development of other cell types, the researchers explained yesterday (November 15) in Cell Stem Cell.
Analyzing how stem cells become muscle and brain cells, the team was able to tweak the protocol to form more kidney cells and fewer off-target cells. By inhibiting proteins and enzymes essential for brain cell development, such as BDNF and its receptor NTRK2, for example, the researchers could reduce the number of neurons by about 90 percent in the kidney organoids.
H. Wu et al. “Comparative analysis and refinement of human kidney organoid differentiation and single cell transcriptomics,” Cell Stem Cell, doi:10.1016/j.stem.2018.10.010, 2018.