Fig. 4.

Suppressing Hap1 expression decreases insulin release in β-cell lines. a Western blotting of Min6 cells showing that Hap1 protein level was reduced by adenoviral Hap1 shRNA treatment, but not by scrambled shRNA control (left panel). The ratio of Hap1 to tubulin is also presented (right panel). b Min6 cells treated with Hap1 shRNA displayed a significant reduction in insulin (ng/mg protein) release after 20 mM glucose stimulation for 10 min. The basal level of glucose is 2.8 mM. c The percentage increase of insulin release relative to the unstimulated in Min6 cells treated with scrambled or Hap1 shRNA. (n = 9, **p < 0.01). d Western blots of NIT-1 cells treated with Hap1 shRNA or scrambled shRNA. e, f Insulin levels in lysates (total insulin) of NIT-1 cells (e) and medium (released insulin) (f) at 0, 10, and 90 min after 20 mM glucose stimulation. (*p < 0.05, **p < 0.01 n = 10–20)