Supplementary Data

• Supplementary Figure 1 - Representative flow cytometry plots of dispersed human islet cells from a subject with Type 2 diabetes (A-F). Dispersed islet cells from the islet digests were fixed and immunolabelled for vimentin and insulin (F). The proportion of labelled cells was determined (rectangle, % total cells). Viable single cells were gated (A,D) and controls with no labelling (B), single vimentin (C) or insulin (E) labelling were used to demonstrate specificity of labelling. (F) cells labelled for both insulin and vimentin from the same subject. (PDF 406 KB)
• Supplementary Figure 2 - Electron microscopical immunogold labelling. Sections of isolated islets from non-diabetic donors were immunogold labelled for vimentin (A) and cathepsin D (B) (A) Part of an islet including a perivascular macrophage (mf) and endothelial cell (e) bordering a islet capillary (cap). Vimentin (15nm gold) labelling is on intermediate filaments in these mesenchymal cells (arrows). An adjacent ungranulated cell (C) with a large nucleus (N) in the islet was not labelled for vimentin. Scale bar 1.0µm. (B) Non-diabetic human islet β-cells labelled for the lysosomal marker cathepsin D (10nm gold). Labelling is present in small primary lysosomes (l) and at the edge of a larger lipofuscin body (lb) (arrows). i=insulin granules; n=nucleus. Scale bar 500nm. (PDF 1523 KB)
• Supplementary Figure 3 - : Immunofluorescent labelling for vimentin, active caspase 3, N-cadherin and amyloid in human post-mortem pancreatic sections. (a,b,c,d) Histological section from a Type 2 diabetic patient labelled for vimentin (a, green), active Caspase 3 (C3)(b, red), insulin (c, blue). Note that C3/ ins positive cells (arrows) are not vim+ve. 50 islets were examined from 2 donors for C3 positivity; a total of only 10 endocrine cells were found to be caspase 3 positive and all of them were vimentin negative (e,f,g,h) Histological section from a Type 2 diabetic patient labelled for vimentin (e,green), N-cadherin (f,red), insulin (g, blue). N-cadherin is present throughout the islet and evident in some ins+, vim– cells (white arrows). Vim+/ N-cadherin+ cells which are ins- (green arrows) are also present in islets. (i,j,k,l) Histological section from a Type 2 diabetic patient stained for islet amyloid with thioflavin S (i, green) (green arrow), and immunolabelled for vimentin (j, red) and glucagon (k,blue). One cell is vimentin and glucagon positive (white arrows). There was no significant increase in vim+ endocrine cells in islets containing amyloid deposits compared to amyloid-free islets. (PDF 4171 KB)
• Supplementary Figure 4 - Immunofluorescent labelling for vimentin, insulin, and Nkx6.1 or Pdx-1. (A) Islet labelled for vimentin (white), insulin (red) and Nkx6.1 (green). Insets show a cell triple positive for insulin, vimentin, and Nkx6.1. Scale bar 50 µm. (B). Islet labelled for vimentin (white), insulin (red) and Pdx-1(green nuclei) to demonstrate nuclear localisation of Pdx-1 in the very few cells that were positive for vimentin, insulin and Pdx-1. Insets show a cell triple positive for vimentin, insulin and Pdx-1. Scale bar 50 µm. (PDF 809 KB)
• Supplementary Figure 5 - Single-cell RNAseq data from the online resource of the Sandberg laboratory (Segerstolpe et al 2016 Cell Metab 24, 593-607). Boxplots summarising VIM expression levels for every donor (shown in different shades of each colour) in alpha and beta cells. The first 6 boxes correspond to healthy individuals and the last 4 to individuals with T2D.
• Supplementary Table 1 - General characteristics of human pancreas donors used in the quantitative immunolabelling analyses. ND, Non-diabetic; T2DM, Type 2 diabetic; BMI, body mass index; DBD, donation after brain death; DCD, donation after circulatory death; Ox, Oxford; Lei, Leiden; n/a, not available. (PDF 64 KB)
• Supplementary Table 2 - General and metabolic characteristics of non-human primates. FPG, fasting plasma glucose; IRI, immunoreactive insulin; n/a, not available; mmol/l, millimoles/litre; pmol, picomoles/litre; ND, non-diabetic; HI, hyperinsulinaemic; DM, diabetic. (PDF 85 KB)
• Supplementary Table 3 - Primary and Secondary antibody information. (PDF 83 KB)
• Supplementary Table 4 - Human isolated islet donor details (PDF 81 KB)