Fig. 2.

Human beta cells are organised structurally using conventional polarity determinant proteins. (a) Immunofluorescence images of an islet within a pancreatic slice demonstrating that in beta cells (insulin, grey), Dlg is enriched (green) around the membrane including the vascular face (labelled with laminin, red) and lateral domains. (b) Fluorescence intensity was assessed at plasma membrane domains shown in the cell diagram 1: vascular face; 2: lateral; 3: avascular face. Data are representative of 2 donors; n=30 cells with 15 cells from 3 islets per donor. (c) 3D heat map representation (low, blue; high, red) of fluorescence intensity using cell circumference fluorescence at each z-stack, demonstrates that Dlg is dispersed across the cell membrane. (d) Representative immunofluorescence images (insulin, grey; scribble, green; laminin, red) and (e) fluorescence intensity analysis show scribble is similarly distributed across the cell membrane. Data are representative of 2 donors; n=30 cells with 15 cells from 3 islets per donor. (f) 3D heat map of fluorescence intensity shows an enrichment of scribble on the cell membrane. (g) Representative immunofluorescence images (insulin, grey; Par3, green; laminin, red) and (h) fluorescence intensity analysis show Par3 is enriched in a discrete avascular domain away from the capillaries. Data are representative of 3 donors; n=45 cells with 15 cells from 3 islets per donor. (i) 3D heat map of fluorescence intensity demonstrates that Par3 signal is enriched on the cell membrane away from the vascular face. The arrowheads in (a, d, g) indicate the cell used in the heat maps in (c, f, i). Scale bars: 50 μm on whole islet images; 10 μm on zoomed-in images and 3D heat maps. Data represent mean ± SEM in (b, e, h). Data were collected from both pancreatomised and cadaveric donor samples. ***p<0.001. Ins, insulin; Lam, laminin; Scrib, scribble