Figure 4.

HSP expression in response to short-term hypoxia. RT-PCR indicated a significant induction of HSP70 expression and a general increase in HSP40 and HSP90 expression in neonatal (A) and adult (B) CPCs following pretreatment with short-term hypoxia (n=6 neonatal clones, n=4 adult clones). Flow cytometry-based analysis of HSP40, HSP70, and HSP90 (C), indicating a significant increase in expression of HSP40 in neonatal and adult CPCs and a significant increase in expression of HSP70 in neonatal CPCs (n=3 for each age group). Adult CPCs endogenously express lower levels of HSP70 compared to neonatal CPCs (D). Since HSP40 induction was found to be significant by flow cytometry, but not by RT-PCR, western blot analysis was used to assess the induction of HSP40 (E) as well as HSP90 (F) in both neonatal and adult CPCs. *P < 0.05; **P < 0.01. Values reported as the average ± S.E.M.