M1 Muscarinic Receptor Activation Mediates Cell Death in M1-HEK293 Cells
Figure 4
Chronic M1 mAChRs activation induces HEK293-M1 cell death.
(A) Hoechst staining of HEK293-M1 and HEK293-Vec treated with water control (vehicle) or 100 µM carbachol for 24 h. The arrows point to condensed (possibly apoptotic) nuclei that were present in carbachol-treated HEK293-M1 cells. Note the substantial cell loss in the M1 expressing HEK cells, but not in the vector transfected HEK cells. Scale bar: 25 µm. (B) The extent of cell loss was investigated further using the MEK-inhibitor UO126. Hoechst stained cells were quantified using Discovery-1 and Metamorph analysis. Statistical significance: *** denotes p<0.001 compared with all other conditions. Note that UO126 did not significantly affect the carbachol response (ns) (C) HEK293-M1 cell counts across a range of 24 h carbachol treatments also showed that cell death occurred in a concentration-dependent manner. Data are representative of at least three independent experiments.