MSC-CM stimulates morphological maturation of OPCs.

<p>Mesenchymal stem cell conditioned medium (MSC-CM) accelerates maturation of cultured oligodendroglial progenitors cells. We identified six distinct morphologies (see bottom), from a very low number of processes in progenitor cells to multiple process-bearing cells (low, medium, high) to mature cells with a very high degree of arborisation or flattened appearance (sheaths). (<b>A–D</b>) Analysis of OPC morphology distribution revealed an MSC-CM-dependent shift towards more mature cells (black bars <b>α</b>-MEM treated cells; grey bars MSC-CM stimulated cells) after one (<b>A</b>), three (<b>B</b>), six (<b>C</b>) and nine days (<b>D</b>). (<b>E,F</b>) Representative citrine labelled OPCs revealing advanced morphologies and promoted sheath formation (arrows) upon MSC-CM stimulation after nine days. Data are shown as mean values ± SEM derived from n = 5 experiments. t-test (ns: not significant, * P<0.05; ** P<0.01; *** P<0.001). Scale bar: 50 µm.