Figure 5.

Heat‐shock protein 90α (hsp90α) was not released in response to altered hypoxia inducible factor 1α (HIF‐1α) activity. Human βLox5 and islets were treated for 24 hr with media alone (Ctrl) or interleukin‐1β (IL‐1β), tumour necrosis factor‐α (TNF‐α) and interferon‐γ (IFN‐γ) (Cyt). Expression levels of HIF1A and VEFGA transcripts were measured in βLox5 (a, b) and islets (c, d) by quantitative RT‐PCR. Human βLox5 cells were treated for 6 hr at 37° with media alone, 10 nm chetomin (e), a HIF‐1α inhibitor, or 100 μm DMOG (f), a HIF‐1α stabilizer, followed by 24 hr treatment with pro‐inflammatory cytokines. Extracellular hsp90α levels were detected by ELISA. Data are presented as relative to control cells without drug treatment or cytokines. Extracellular hsp90α values ranged between 1·4 and 46·5 ng/ml (e) and 3·0 and 23·9 ng/ml (f). Data are mean + SEM of n = 3 or n = 4 experiments or mean ± SEM of n = 4 islet donors. *P < 0·05, **P < 0·01, ***P < 0·001.