Serum starvation reduces proliferation and induces apoptosis and Nestin expression in human PAECs.

(A) qRT-PCR expression of MKI67 (Ki67) in human PAECs cultured for 24h with complete EGM-2 or basal EGM (= serum starvation). (B-C) 24h serum starvation reduces proliferation in PAECs. (B) Representative histograms and (C) quantification. (D-E) 24h serum starvation promotes apoptosis measured as Annexin V (AV)+ 7-aminoactinomycin (7-AAD)- cells using flow cytometry. 7-AAD was added to exclude necrotic cells, which are 7-AAD+. (D) Representative dot plots and gating. (E) Quantification. (F) qRT-PCR of mRNA expression of NES and CXCL12 after 24h serum starvation. (G) Representative Western blots show that serum starvation promotes Nestin protein expression and increases caspase-3 cleavage, but not CXCL12 protein expression. (H) Quantification of Western blots in (G). n = 3 per group (H), n = 4 per group (E), n = 6 per group (A, C, F). All data shown as mean+SEM. *PP<0.01 (t-test, Mann-Whitney).