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. 2011 Oct 18;6(10):e26298. doi: 10.1371/journal.pone.0026298

Figure 5. Ectopic PDX-1 expression induced insulin and glucagon expression and promoted glucose-regulated C-peptide secretion.

Figure 5

Double immunofluorescence of human keratinocytes isolated from neonatal foreskin treated with (a, d) control Ad-β-gal or (b–c, e–f) Ad-PDX-1 adenovirus for 7 days. Immunofluorescence analyses showed co-localized expression of (a–c) PDX-1(green) and insulin (red) and (d–f) PDX-1(red) and glucagon (green). The nuclei were stained with DAPI (blue). (a–b, d–e). Original magnification ×20 (c, f); original magnification (confocal microscope) ×90. (g) Human keratinocytes were infected with Ad-β-gal or Ad-PDX-1, both at 1000 moi, and analyzed for secretion of processed insulin into the culture medium upon exposure to 2 and 25 mM glucose or 25 mM 2DOG. C-peptide in the medium was measured with a specific RIA kit (Linco human c-peptide no crossreactivity with pro-insulin). Data represents n≥7 samples in four independent experiments.