(A) Experimental paradigm to assess the effect of lentivirally expressed h-aSyn on
primary OPC maturation. One day after seeding, transduction (TD) was performed. After
another day, differentiation was started. MC = medium change. (B) Representative
pictures taken at day 2 of differentiation for the immunocytochemical evaluation of OPC
purity and survival as well as lentiviral transduction efficiency. Notice the absence of
h-aSyn immunoreactivity (red) in mock as well as CTRL transduced cultures and the
completely overlapping expression of GFP (green) and h-aSyn in SYN transduced cells. Note
that most DAPI-positive cells (blue) express the oligodendrocyte lineage marker Olig2
(magenta). Scale bar: 50μm. (C) Determination of lentiviral transduction
efficiency as percentage of GFP-positive cells of total DAPI-positive cells (n=3).
Both lentiviruses result in a high and comparable number of transduced cells (total means:
CTRL 72.9%, SYN 65.6%). (D) Quantification of culture purity illustrated
as the percentage of Olig2-positive cells of total DAPI-positive cells (n=3). The
number of Olig2-positive cells changes neither during differentiation nor by comparing
non-transduced and transduced cultures (total means: mock 68.2%, CTRL
68.1%, SYN 70.1%). (E) Immunocytochemistry (n=3) confirms the
absence of an increased apoptotic profile in SYN compared to CTRL transduced
oligodendrocytes. Arrows in representative pictures taken at day 2 of differentiation
depict apoptotic Olig2-positive cells expressing activated Caspase 3 (act-Casp3).
Quantification reveals ≤10% act-Casp3-positive oligodendrocytes during
differentiation of both CTRL and SYN transduced oligodendrocytes. Scale bar =
50μm.