Mitochondria dysregulation contributes to secondary neurodegeneration progression post-contusion injury in human 3D in vitro triculture brain tissue model.
Traumatic Brain injury-induced disturbances in mitochondrial fission-and-fusion dynamics have been linked to the onset and propagation of neuroinflammation and neurodegeneration. However, cell-type-specific contributions and crosstalk between neurons, microglia, and astrocytes in mitochondria-driven neurodegeneration after brain injury remain undefined. We developed a human three-dimensional in vitro triculture tissue model of a contusion injury composed of neurons, microglia, and astrocytes and examined the contributions of mitochondrial dysregulation to neuroinflammation and progression of injury-induced neurodegeneration. Pharmacological studies presented here suggest that fragmented mitochondria released by microglia are a key contributor to secondary neuronal damage progression after contusion injury, a pathway that requires astrocyte-microglia crosstalk. Controlling mitochondrial dysfunction thus offers an exciting option for developing therapies for TBI patients. Overall design: To investigate the role of mitochondria dysfunction in brain injury-induced neurodegeneration. We performed gene expression profiling analysis using data obtained from bulk RNA-sequencing of human 3D in vitro tricultures composed of neurons, astrocytes and microglia with or without selecting mitochondria fission inhibitor P110, 24 hours after Controlled cortical impact injury. Human microglia cells were differentiated from 2 healthy donors - human YZ1 and ND41866*C; data presented from 2 independent experiments (microglia differentiation + tricultures seeding); the injured groups were compared to their corresponding sham groups with or without P110 treatment. Human neurons were differentiated from induced Neural Stem cells developed in Prof. David Kaplan lab; astrocytes were human primary astrocytes purchased from Sciencell Research Laboratories