Figure 7.
TGFβ cooperates with neuregulin-1 in promoting Schwann cell proliferation in vitro. A, Schwann cells from wild-type (wt) and mutant mice were isolated, exposed to increasing concentrations of neuregulin-1 (NRG-1) for 10 h, and tested for BrdU incorporation. This showed that mutant cells proliferate at a reduced rate, which is similar to that seen when wild-type cells were exposed to neuregulin-1 in the presence of SB431542 (10 μm), a TGFβ receptor blocker [averages of three separate experiments, each using triplicate coverslips; wild type and P0 CRE/TβRIIf/f represent littermates from three separate litters]. B, BrdU incorporation in wild-type cells exposed to increasing concentrations of neuregulin-1 in the presence or absence of 5 ng/ml TGFβ. Note that TGFβ strongly promotes the proliferation induced by low concentrations of neuregulin-1 (averages of three separate experiments, each using triplicate coverslips).