Fig. 1

hUCB-MSC treatment prevents neuron loss in the hippocampus after severe IVH injury. a, b In P4 rat pups, IVH was induced by IC injection of a total of 200 μl of fresh maternal whole blood (100 μl each into the right and left ventricles). Normal control rats received a sham operation without IC blood injection. At P5 (1 day after IVH), severe intraventricular hemorrhage (IVH) was confirmed by brain magnetic resonance imaging (MRI), and IVH rat pups showing minimal or non-visible IVH on the brain MRI were excluded. At P32 (26 days after MSC treatment), IVH damage and its recovery by MSC treatment were measured by MRI. c At P7 after animal modeling of intraventricular hemorrhaging, rat brain was embedded in paraffin. Serial hippocampal coronal sections were stained with cresyl violet (left). The area of pyramidal neurons and number of pyramidal neurons were quantified using ImageJ software (right). d After severe intraventricular hemorrhage and transplantation of hUCB-MSCs, P7 rat brain was fixed with 4% PFA. Mesenchymal stem cells were stained with anti-human mitochondria antibody. Scale bar, 50 μm (periventricular zone), 500 μm (hippocampus). D.G: dentate gyrus. e In P7 rats, entorhinal-hippocampal slice cultures were prepared after intraventricular hemorrhage. Slices are stained with cresyl violet at DIV7 (left). The area of pyramidal neurons was quantified in a black box in ImageJ software (right). MSC markedly protected against neuronal cell death in the CA1 region of the IVH model. Images shown here are representative of at least three independent experiments (n ≥ 15 per group). Data are shown as mean ± SEM. *p < 0.05, **p < 0.005 versus the indicated group