Fig. 3: Endothelial cells and pericytes transfer functional mitochondria to astrocytes in a 3D assembloids model of human BBB.
From: Role of pericytes in blood–brain barrier preservation during ischemia through tunneling nanotubes
A, B Functional mitochondria from either pericytes or brain endothelial cells were stained with MT (red), while astrocyte membranes were labeled with CM (blue). To generate BBB assembloids, labeled astrocytes were cultured with either labeled pericytes and unlabeled endothelial cells (A) or labeled endothelial cells and unlabeled pericytes (B). After 2 days in culture, assembloids were fixed and analyzed by confocal microscopy for MT localization. 3D reconstructions and Z-projections acquired at low magnification show either pericytes (A1, red) or endothelial cells (B1, red) localized in the assembloid shell, with astrocytes localized in the assembloid core (A1, B1, blue). In both cases, high magnification analysis reveal MT-stained mitochondria (red) in the assembloid core (A2/A3; B2/B3). Representative images from N = 3 independent preparations with N ≥ 3 assembloids per experiment. C, D Immunofluorescence and high magnification confocal analysis of the assembloid core using anti-GFAP antibodies. XY planes and Z projections of the assembloid core show MT-stained mitochondria (red) from either pericyte (C) or endothelial cells (D) inside GFAP-positive astrocytes. Representative images from N = 2 independent experiments in which N ≥ 6 assembloids per experiment were analyzed.
