Influence of ARs on differentiation
of MLPC into oligodendrocytes.
(A) Phase contrast images of cells after differentiation for 30 days,
in the presence of NE, that exhibited a complex multipolar morphology.
(B) Cells differentiated for 30 days in the medium in which NE was
substituted with the β-AR agonist isoproterenol and the α1-AR
agonist phenylephrine. Cells were morphologically comparable to cells
treated with NE. (C) Cells differentiated in the presence of the β-AR
agonist isoproterenol frequently displayed a bipolar morphology, resembling
immature oligodendrocyte progenitors. (D) Substitution of NE with
the α1-AR agonist phenylephrine resulted in a mature morphology
in 10% of cells. The remainder of the cells showed only partial process
development or remained flat. (E) Cells differentiated for 30 days
without activation of ARs by NE or AR agonists continued to exhibit
a mostly flat morphology. (F) Stimulation of both α1- and β1-ARs
is required for optimal differentiation. Immunocytochemical analysis
of cells differentiated for 30 days in the presence of the β-AR
agonist isoproterenol and the α1-AR agonist phenylephrine. Cells
stained positively for A2B5, O4, O1, and MBP. Scale bars are 100 μm.
(G) Comparison of differentiation levels achieved by activation of
both ARs by NE, by both AR agonists (Iso+Phen), by β-AR by isoproterenol
(Iso), and by α1-AR agonist phenylephrine (Phen). Error bars
represent the SD.