Journal: bioRxiv
Article Title: Divergent Cell-Type Specific Hypoxia Responses in Human Stem Cell–Derived and Primary Islets
doi: 10.1101/2025.07.16.665006
Figure Lengend Snippet: Divergent functional, metabolic, and cellular responses of primary and SC-islets to acute hypoxia. Functional, metabolic, and immunohistochemical analyses of primary islets (top row, A-E) and SC-islets (bottom row, F-J) after exposure to 1% O 2 for 0, 6, 24, or 48 hours. (A, F) Representative immunohistochemical images of (A) primary and (F) SC-islet sections at each timepoint. Panels show co-staining for DAPI (blue), C-peptide (Cpep, green), and PDX1 (red); DAPI, glucagon (GCG, green), and somatostatin (SST, cyan); and DAPI and BNIP3L (red). Scale bars = 200 µm. (B, G) Absolute insulin secretion in response to low (2 mM, grey bars) and high (20 mM, dark bars) glucose for (B) primary and (G) SC-islets. (C, H) Oxygen consumption rate (OCR) of (C) primary and (H) SC-islets, measured via Seahorse metabolic flux analysis. Different colored lines represent islets recovered after the indicated duration of hypoxia. The traces show metabolic responses to sequential injections (indicated by dashed lines) of glucose (20 mM), oligomycin (1.5 µM), FCCP (0.5 µM), and finally rotenone/antimycin A (0.5 µM). (D, I) Glucose-stimulated insulin secretion (GSIS) stimulation index (SI) for (D) primary and (I) SC-islets, calculated as the ratio of high-to-low glucose secretion. (E, J) Extracellular acidification rate (ECAR) of (E) primary and (J) SC-islets, measured concurrently with OCR. *Data in (B, D, G, I) are presented as mean ± SEM of n=3 (primary) or n=4 (SC-islets) biological replicates; individual data points are shown as open circles. Data in (B, E, G, J) are representative traces from a single experiment, with lines showing the mean ± SEM of technical replicates. For insulin secretion (B, G) and stimulation index (D, I), statistical significance was assessed using repeated measures ANOVA followed by pairwise t-tests with Bonferroni correction for post-hoc analysis. Significance is denoted as *p < 0.05, **p < 0.01.
Article Snippet: DAPI (ThermoFisher; D1306) was used for nuclear staining.
Techniques: Functional Assay, Immunohistochemical staining, Staining