Peripheral blood EOSs from 10
asthma patients were cultured in the presence or absence of
simvastatin (1, 5, 10, 20 micromol/L), together with or without
mevalonate (100 micromol/L) for 6, 12, 24, and 48 h. Apoptosis was monitored by
annexin V/PI staining and flow cytometry.
Caspase-3 was measured by
enzyme-linked
immunosorbent assay (ELISA).
RESULTS: EOSs were particularly susceptible to apoptosis after incubated with 5 micromol/L
simvastatin for 6, 12, 24, and 48 h [the rates of EOSs undergoing apoptosis were: (23 +/- 3)%, (24 +/- 3)%, (41 +/- 6)%, (70 +/- 12)% in control and (32 +/- 4)%, (47 +/- 7)%, (62 +/- 9)%, (86 +/- 14)% in
simvastatin; compared with control at the same time point: P = 0.000]. EOS apoptosis occurred at doses of 1 micromol/L and was already maximal at 5 micromol/L after incubated with
simvastatin for 12 h [the rates of EOSs undergoing apoptosis were: (24 +/- 3)% in control, (37 +/- 3)%, (51 +/- 3)%, (53 +/- 4)%, (52 +/- 4)% in 1, 5, 10, 20 micromol/L
simvastatin, respectively; compared with control: P = 0.000]. The level of
caspase-3 in EOSs was consistent with the rate of cell apoptosis [(8 +/- 3) microg/L in control, (14 +/- 4), (22 +/- 4), (24 +/- 4), (23 +/- 5) microg/L in 1, 5, 10, 20 micromol/L
simvastatin, respectively; compared with control: P = 0.000 - 0.003]. However, Co-incubation of
simvastatin with
mevalonate (the production of HMGR) completely reversed the activity of
simvastatin on EOS apoptosis even when the highest
simvastatin (20 micromol/L) dose was used; the rates of EOSs undergoing apoptosis in the control,
mevalonate plus
simvastatin and
simvastatin alone were (24 +/- 3)%, (52 +/- 4)% and (25 +/- 3)%, respectively; while the
caspase-3 levels were (8 +/- 3) microg/L, (23 +/- 5) microg/L and (9 +/- 3) microg/L, respectively.
CONCLUSION: