Figure 6

Overexpression of PDE6D accelerates the proliferation rate of A549 AECs. (A) Demonstration of PDE6D overexpression in A549 cells: upper panel: increased PDE6D (~17 kDa) immunoreactive protein 0-48 h post transfection with pcDNA3.1/His-PDE6D vector (PDE6D). These expressional changes were not observed in pcDNA3.1/His-lacZ empty vector (EV) or no DNA transfected (only lipofectamine (Lf)) cells. Middle panel: The membrane was probed with anti-His-HRP conjugated antibody. A band of ~23 kDa was detected in the PDE6D transfected cells but not in EV transfected or Lf treated cells. The bottom panel represents GAPDH (~37 kDa) used as a loading control. (B) Bar graph presentation of cell counts from PDE6D overexpressing cells 24 h post serum stimulation. Data were expressed as % of control. Serum stimulation was significant ^# P < 0.05 versus 0.1% FBS stimulated cells. Cell number from PDE6D overexpressing cells was significantly increased as compared to EV transfected and Lf treated cells (*P < 0.01 versus EV transfected cells, ^† P <0.01 versus Lf treated cells). (C) Bar graph presentation of [³ H]-Thymidine uptake in PDE6D overexpressing cells 24 h post serum stimulation. Data were expressed as cpm/×10⁵ cells. Serum stimulation was significant ^# P < 0.001 versus 0.1% FBS stimulated cells. [³ H]-Thymidine uptake of PDE6D overexpressing cells was significantly increased as compared to EV transfected and Lf treated cells (*P < 0.01 versus EV transfected cells, ^† P <0.01 versus Lf treated cells). Lf concentration was kept constant throughout the experimental settings and had no effect on cell viability (P = 0.3552).