Ction compared with fasting at 0 min in controls (, n = 4) and bigenic (, n = 9). P 0.025 compared with 0 min. P 0.004 comparing groups at 15 min. D : Isolated islets from 11-week-old bigenic mice (both CAIICre;Pdx1FlFl and CAIICre;Pdx1Fl+, , n = 10 animals) in sequential static incubation had impaired glucose-responsive insulin secretion compared with controls (, n = 10 animals) (D) and reduce percentage insulin content secreted (E) despite the fact that the islet insulin content was not significantly diverse (F). Data are mean 6 SEM. P 0.007. Even though every islet aliquot with values for each glucose concentrations (n = 23 for bigenic and n = 26 for handle) was employed for the averaging, the basal levels and islet insulin content don’t differ, but the bigenic islets showed a modest glucose-stimulated insulin release (2.six mmolL glucose: three.6 6 1.1 pg insulinng DNA; 16.8 mmolL glucose: 12.5 six three.6 PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21269526 pg insulinng DNA; P 0.003, paired t test).a section of CAIICre;Pdx1Fl pancreas, some islets (no matter whether large, modest or as smaller clusters) could possibly be identified containing cells with really low to undetectable PDX1 expression. Some islets had strongly homogeneous PDX1 staining, having a minority of cells displaying little or no PDX1 staining. The intensity of insulin staining also varied similarly. Hence, there was a mixed population of islets within the CAIICre;Pdx1Fl3462 DIABETES, VOL. 62, OCTOBERmice (Fig. 5B): about 30 had homogeneously high or typical PDX1 expression, 20 had low to undetectable expression, and 50 displayed mixed-level expression. PDX1nullinsulin+ cells accounted for 31 six 7.7 of all insulin+ cells (n = 3 animals with no less than 18 isletaggregates, and 625 insulin+ cells counted for each). The loss of PDX1 expression was similarly noticed within the pancreas of 4-week-olddiabetes.diabetesjournals.orgL. GUO AND ASSOCIATESFIG. four. Duct-specific Pdx1-deficient mice had related islet and b-cell mass as controls. Islet mass at 4 and ten weeks (A) and b-cell mass at 4 weeks (B) didn’t differ between handle () and CAIICre;Pdx1FlFl () male mice (four weeks: n = 5 manage, n = 6 bigenic; ten weeks: n = three each groups). At four weeks the relative density of b-cells (C) differed, but mainly because the pancreatic CP21R7 weights (D) had been elevated within the bigenic (even though they had equivalent body weights) mice (E), the absolute b-cell mass was not decreased inside the bigenic mice. F: At four weeks, though there was no difference in proliferation of acinar or duct (CK+) cells amongst control and bigenic mice, proliferation in insulin+ cells was enhanced in each bigenic groups (G) compared with controls (H) with Ki67+ (red), PDX1 (green), and nuclei DAPI (blue). Information for person animals are shown in F. I: Some Ki67+insulin+ (blue) cells have been PDX12. Information are imply 6 SEM. P 0.05.CAIICre;Pdx1FlFl (Supplementary Fig. four) and of CAIICre; Pdx1Fl+ mice at each ages (information not shown). When the ROSA26ReYFP reporter gene was introduced into the CAIICre; Pdx1 mice for lineage tracing, some lobes had YFP+ acinar and islet cells (Fig. 6A and Supplementary Fig. five). These YFP islets have some b-cells with low to undetectable PDX1 expression, and others cells had powerful PDX1 expression. In islets of 10- to 12-week-old mice, the b-cell transcription element MAFA had a similarly mixed expression pattern to that of PDX1. Within precisely the same section, some islets in the bigenic mice had small to no MAFA protein expression, within a hugely heterogeneous pattern, whereas other individuals had expression indistinguishable from controls (F.
