PAC1 isoforms differentially regulate DNA synthesis and
proliferation. At 2 DIV, transfected cortical precursors were incubated
for 6 h with 10 nM PACAP. Cultures were pulsed with BrdUrd (10
μM) for the final 2 h and processed for double GFP/BrdUrd
labeling. (a) BrdUrd labeling index of transfected
cells. PACAP treatment decreased DNA synthesis in GFP- or
GFP/PAC1short-transfected cells, whereas the peptide increased
mitosis in GFP/PAC1hop-transfected cells. Values are expressed as %
± SEM (n = 9). Differs from vehicle-treated group:
*, P < 0.05; **,
P < 0.01. (b) Transfection rates in
corresponding cultures. PACAP treatment resulted in an overall increase
in GFP-IR cell number (P < 0.05). Values are
expressed as % of GFP-IR cells/total ± SEM. (c
and d) GFP/PAC1short- or GFP/PAC1hop-transfected
cells were treated daily with PACAP for 5 days and processed for GFP
immunostaining. (c) Example of a clone at 5 DIV. (Scale
bar = 10 μm.) (d) Quantification of GFP-IR clones
(≥4 cells) at 5 DIV. Data are expressed as mean number of clones per
ten fields ± SEM (n = 8, four experiments).
*, unpaired t test, P <
0.02.