Fig. 2

PCC1 alleviates apoptosis of NP cells caused by acidic pH stress. (A) The protein levels of Bax, Bcl-2, cleaved caspase-3, and caspase-9, were confirmed by western blotting. (B) The expression levels of Bax, Bcl-2, cleaved caspase-3, and caspase-9, were determined by qRT-PCR. (C) NP cells stained with Annexin V-FITC and PI and then analyzed by flow cytometry. Cells positively stained for Annexin V-FITC and negatively stained for PI were scored as early apoptotic. Cells positively stained for both Annexin V-FITC and PI were scored as late apoptotic or necrotic. (D) Apoptotic rates of each group; values are expressed as mean ± standard deviation. (E-F) According to the results of TUNEL staining, the rate of TUNEL positive cells increased in the acidic pH stimulated group, while the rate of TUNEL positive cells decreased in the PCC1 pretreated group. Control, NP cells were treated by PBS; PCC1 0µM, NP cells were treated by acidic pH stress (pH 6.5–6.7) and PCC1 (0µM); PCC1 10µM, NP cells were treated by acidic pH stress (pH 6.5–6.7) and PCC1 (10µM); PCC1 20µM, NP cells were treated by acidic pH stress (pH 6.5–6.7) and PCC1 (20µM); PCC1 40µM, NP cells were treated by acidic pH stress (pH 6.5–6.7) and PCC1 (40µM). Three independent experiments were performed. ⁎p < 0.05, ⁎⁎p < 0.01 versus control