MIT researchers from the Picower Institute and the Koch Institute, in work spanning the Langer and Tsai laboratories, have invented a new human brain tissue model that could reshape disease research and drug discovery. Reported in the Proceedings of the National Academy of Sciences, the Multicellular Integrated Brains, or miBrains, are three-dimensional cultures grown from a donor's induced pluripotent stem cells that integrate all six major brain cell types, including neurons, glia and blood vessels, in a unit smaller than a dime.
Because each cell type is cultured separately before assembly, any of them can be gene-edited independently, and the team tuned cell ratios and employed a hydrogel scaffold so the tissue forms functional neurovascular units and a blood-brain barrier. That realism paid off immediately in a test case on APOE4, the strongest genetic risk factor for Alzheimer's disease: APOE4 astrocytes displayed Alzheimer's-linked immune activity only within the full multicellular environment, and tau pathology depended on cross-talk between astrocytes and microglia.
The implications for translational neuroscience are significant. Conventional cell cultures miss the intercellular conversations where much disease biology lives, while animal models diverge from human genetics. A personalised, customisable system built from a patient's own cells offers a middle path, one that could make preclinical findings in neurodegeneration, and eventually drug screens, considerably more predictive.