Single-Cell Mass Cytometry Analysis of the Human Endocrine Pancreas

Abstract

Summary The human endocrine pancreas consists of multiple cell types and plays a critical role in glucose homeostasis. Here, we apply mass cytometry technology to measure all major islet hormones, proliferative markers, and readouts of signaling pathways involved in proliferation at single-cell resolution. Using this innovative technology, we simultaneously examined baseline proliferation levels of all endocrine cell types from birth through adulthood, as well as in response to the mitogen harmine. High-dimensional analysis of our marker protein expression revealed three major clusters of beta-cells within individuals. Proliferating beta-cells are confined to two of the clusters.

Pancreas regeneration

“…These data suggest that human β-cells may be heterogeneous, and that a subpopulation of β-cells may resist the autoimmune attack. These clinical observations are consistent with accumulating evidence that mouse and human β-cells in normal islets are heterogeneous in their molecular signatures or proliferativepotential 146–148 . A subset of β-cells has also been proposed to serve as ‘hubs’ for initiating pulsatile insulin release 149 .…”

Age-dependent human β cell proliferation induced by glucagon-like peptide 1 and calcineurin signaling

“…These findings are also supported by studies here (Figure 2A) and elsewhere (10,33) revealing that GLP1R expression did not detectably change with age in human islet β cells. An additional finding from our work is that human α cell and δ cell proliferation also appears to decline with age, corroborating a recent mass cytometry-based study (47). However, unlike in juvenile human β cells, Ex-4 did not stimulate proliferation of these other islet cell subsets.…”

“…For example, age-dependent reduction of receptors for PDGF and PRL in human β cells has been noted (4,14). Similarly to PDGFR, GLP-1R signal transduction can stimulate Ca 2+ transients to activate NFATC transcription factors (47). Thus, we speculate that PDGFR and GLP-1R may signal in parallel to regulate β cell proliferation, a possibility requiring further studies.…”

Evidence for Loss in Identity, De-Differentiation, and Trans-Differentiation of Islet β-Cells in Type 2 Diabetes

“…However, several lines of evidence now challenge us to further modify this definition. New technologies, including single-cell transcriptomics and mass cytometry, have allowed the field to “drill deeper” into the β-cell mass to more definitively reveal the long-suspected heterogeneity within the insulin + population (Salomon and Meda, 1986; Pipeleers, 1992; Van Schravendijk et al, 1992), especially across species and in non-diabetic vs. T2D donors (Segerstolpe et al, 2016; Wang et al, 2016a,b; Xin et al, 2016). Several recent resource publications shared the single cell transcriptomes of human islet cells under diabetic and non-diabetic conditions (Segerstolpe et al, 2016; Wang et al, 2016b; Xin et al, 2016).…”