To detect the effects of let-7a on MKP1 expression in PC12 cells, cells were assigned to control, mimic, mimic-NC (negative control), inhibitor and inhibitor-NC groups. The control group received no treatment. Mimic, mimic-NC, inhibitor and inhibitor-NC groups were transfected with let-7a mimic, let-7a mimic negative control, let-7a inhibitor and let-7a inhibitor negative control, respectively.
To detect the effects of let-7a and MKP1 on hypoxia-induced PC12 cell apoptosis, wild-type PC12 cells were divided into control, agomir-NC and let-7a groups. PC12 cells over-expressing MKP1 were divided into let-7a + MKP1, control (no treatment), agomir-NC (transfection with let-7a mimic negative control), let-7a and let-7a + MKP1 groups (transfection with let-7a mimic). All groups were incubated in the presence of 200 μM CoCl2 (Sigma-Aldrich, St. Louis, MO, USA) for 24 hours, and were then assessed for apoptosis.