TABLE 2

Exendin-4 stimulates cyclin A2 and PDX-1 in cultured C57Bl6 mouse islets

TreatmentTime (h)
0246812
Transcript
    Cyclin A2PBS10.98 ± 0.111.09 ± 0.091.05 ± 0.041.06 ± 0.100.99 ± 0.07
    Cyclin A2Exendin-412.75 ± 0.47*4.45 ± 0.65*3.88 ± 0.37*4.86 ± 0.54*4.47 ± 0.63*
    Cyclin D2PBS11.09 ± 0.071.07 ± 0.051.06 ± 0.071.05 ± 0.090.93 ± 0.10
    Cyclin D2Exendin-410.99 ± 0.071.08 ± 0.091.02 ± 0.091.18 ± 0.111.0 ± 0.15
    PDX-1PBS11.22 ± 0.090.99 ± 0.0.071.06 ± 0.071.05 ± 0.160.9 ± 0.16
    PDX-1Exendin-411.35 ± 0.261.06 ± 0.132.04 ± 0.67*6.23 ± 2.88*7.49 ± 2.97*
Protein
    Cyclin A2PBS10.96 ± 0.381.13 ± 0.391.13 ± 0.391.14 ± 0400.15 ± 0.40
    Cyclin A2Exendin-411.56 ± 0.40*1.82 ± 0.40*1.68 ± 0.39*2.01 ± 0.39*1.69 ± 0.39*
    Cyclin D2PBS11.09 ± 0.071.07 ± 0.051.06 ± 0.071.05 ± 0.090.93 ± 0.10
    Cyclin D2Exendin-410.99 ± 0.071.08 ± 0.091.02 ± 0.091.18 ± 0.111.0 ± 0.15
    PDX-1PBS11.15 ± 0.351.02 ± 0.351.15 ± 0.351.14 ± 0.350.15 ± 0.36
    PDX-1Exendin-411.18 ± 0.371.55 ± 0.371.67 ± 0.36*1.97 ± 0.36*2.67 ± 0.35*

  • Data are means ± SE. Relative changes of indicated transcripts and immunoblots of indicated proteins in cultured C57Bl/6 islet extracts treated with PBS or 20 nmol/l exendin-4 for 0, 2, 4, 6, 8, and 12 h (n = 4 for each parameter and group). Transcripts were normalized to housekeeping gene 36B4 transcript at corresponding time points and results are fold change over baseline (0 h). Exendin-4 stimulates an early (2–4 h) increase in cyclin A2, whereas PDX-1 transcript increases after 6–8 h. Densitometric analysis of relative protein levels normalized to actin at corresponding time points of three independent experiments are shown as fold change over baseline (0 h). Exendin-4 stimulates an early (2–4 h) increase in cyclin A2, whereas PDX-1 levels increase after 6–8 h.

  • *

    * Significant difference (P < 0.05) from the corresponding control. For details, see text and Fig. 3.