Figure 1.

ACE2 and TMPRSS2 Expression in Isolated Human Islet Cells and Juvenile Pancreas

(A) Relative expression of ACE2 and TMPRSS2 compared with select α (white bars) and β (green bars) cell-type-enriched genes in sorted human islet α and β cells from previously published bulk RNA-seq datasets, reported as transcript per million mapped reads (TPM; n = 7; Blodgett et al., 2015) or reads per kilobase of transcript per million mapped reads (RPKM; n = 8; Arda et al., 2016). Mean expression values are presented as log₂ (TPM+1) or log₂ (RPKM+1) to account for negative values. Dotted line highlights ACE2 and TMPRSS2 expression.

(B) Dot plots of ACE2, TMPRSS2, CTSL, ADAM17, FURIN, TMPRSS4, and DPP4 expression compared with cell-type-enriched genes from three single-cell (sc) RNA-seq datasets (Baron et al., 2016; Kaestner et al., 2019; Segerstolpe et al., 2016). Dot size indicates percentage of cells in a given population expressing the gene; dot color represents scaled average expression. Dotted lines highlight expression of putative SARS-CoV-2 entry machinery. Percentages of β cells expressing and co-expressing these genes are available in Table S1.

(C) Representative images of an isolated islet from an adult human donor (top panels; n = 6 total images analyzed) and a pancreatic section from a juvenile human donor (bottom panels; n = 10 total images analyzed) stained for ACE2 (red; antibody ab15348), insulin (INS; green), glucagon (GCG; white), and DAPI (blue). Dotted yellow line denotes islet area. Human pancreatic donor information is available in Table S2 (donors I1–I3 and J1–J5). See also Figures S1, S2, and S4. Scale bar, 50 μm.