FIG. 6.

Mash1 overexpression in HFC7 cells promotes both neuronal and oligodendroglial specification. (A) Proportions of HFC7 cells from different neural lineages at 4 days after transduction with the VSV-PGK-LacZ and VSV-PGK-Mash1 vectors. Overexpression of Mash1 did not affect the global proportions of Nestin⁺ cells and GFAP⁺ astrocytes, but induced a very significant increase in the proportions of A2B5⁺ cells, a highly significant increase in the proportion of MAP5⁺ neuroblasts, and a significant increase in the proportion of β3 Tubulin⁺ neuroblasts. Most insterestingly, scarce O4⁺ oligodendrocytes appeared as soon as 4 days after Mash1 overexpression. Note that the proportion of MAP2⁺ mature neurons underwent a highly significant decrease, which may reflect either neuronal death or dedifferentiation. (B) Immunofluorescent staining against the various markers tested in A, after hNPC transduction with the VSV-PGK-LacZ (upper cases) and VSV-PGK-Mash1 (lower cases) vectors. (C) Among the Nestin⁺ cells, neither the proportion of Nestin⁺/GFAP⁻ neuroepithelial cells nor that of Nestin⁺/GFAP⁺ astrocytes was affected by Mash1 overexpression. (D) The increase in the proportion of A2B5⁺ cells reflected both a highly significant increase in the proportion of A2B5⁺/MAP5⁺ neuroblasts and a very significant increase in the proportion of A2B5⁺/MAP5⁻ OPCs. Therefore, Mash1 overexpression induced both neuronal and oligodendroglial specification from HFC7 cells. Student's t-test: *P<0.05; **P<0.01; ***P<0.001. Scale bar: 50 μm.