Introduction and Objective: Harmine (H) plus Exendin-4 (E) robustly enhances human β cell regeneration, yet whether H+E influences human β cell senescence is unknown. We developed a computational framework to resolve senescence heterogeneity in scRNA-seq and applied it to test whether H+E modulates senescence programs in cytokine-challenged vs. unchallenged human islets.Methods: We developed a machine-learning workflow integrating distribution-aware senescence labeling with adaptive elastic net regularization. This was applied to scRNA-seq datasets of human islets in basal 4 day culture ± H ± E or treated with cytokines (6h) ± H ± E. Key observations were validated in EndoC-βH1 cells and human islets.Results: This platform prioritized a network of senescence drivers and, importantly, distinguished context-specific senescence nodes across inflammatory and basal settings. In cytokine-treated human islet scRNA-seq, H+E preferentially suppressed a proinflammatory/viral-mimicry senescence program in β cells defined by coordinated induction of SASP genes (CXCL8, CCL2, GDF15), cGAS-STING/ISG signatures (BST2, IFI6, IFIT1, RSAD2, STAT1), and immunogenicity-associated transcripts (IRF1, IRF2, HLA-A/B/C), compared with saline, H or E alone. In contrast, in non-cytokine-treated islets, we primarily found H+E reduced a cell-cycle-linked senescence program (CDKN1A, CDKN2A). Supporting these findings, qPCR/ELISA/immunoblot showed that H+E decreased cytokine-induced cGAS-STING axis outputs (STAT1, IRF1, HLA-B, CXCL10) and reduced secreted chemokines (CXCL8, CCL2, CXCL3), while in basal conditions H+E decreased p21 (CDKN1A) and p16 (CDKN2A) in β cells.Conclusion: Our approach resolves distinct human β cell senescence nodes across inflammatory and basal contexts. H+E attenuates both cytokine-driven cGAS-STING-linked inflammatory/immunogenic senescence and cell-cycle-linked senescence in a context-dependent manner, further supporting beneficial effects of H+E for diabetes treatment.
R.B. Kang: None. E. Oh: None. A. Song: None. A. Wang: None. D. Thurmond: None. A. Garcia-Ocana: Advisory Panel; Current; Paulex Bio. G. Lu: None.
Source link
Leave a Reply