Figure 1: Circulating Progenitor Cell Subpopulations Are Discerned According to High ALDH-Activity and SSC Properties

(A and B) Representative flow cytometry plots using N,N-diethylaminobenzaldehyde (DEAB) to inhibit aldehyde dehydrogenase (ALDH) activity establishing gates for low versus high ALDH-activity. Without inhibition, cells with high ALDH-activity exhibit increased fluorescence intensity (right shift) and detect primitive cells with a self-protective progenitor cell phenotype. High ALDH-activity combined with side scatter (SSC) properties selects for a progenitor cell subpopulation with low intracellular complexity (R1 = ALDHhiSSClow cells), a monocyte subpopulation with intermediate intracellular complexity (R2 = ALDHhiSSCmid cells), and a granulocytic subpopulation with high intracellular complexity (R3 = ALDHhiSSChi cells). (C and D) Representative flow cytometry plots showing the frequencies of each population in control subjects and patients with type 2 diabetes mellitus (T2D). Compared with control subjects, patients with T2D exhibited an increased frequency of ALDHhi cells within the granulocyte subpopulation (R3) and an equal frequency of circulating ALDHhi cells with low (R1) and intermediate (R2) complexity. Values are mean ± SEM. ***p < 0.001 with the Student's t-test.