An integrative approach zinc induced integrated stress response as a key driver for ß cell failure in human type 2 diabetes
Dysfunctional pancreatic islet ß cells are a hallmark of type 2 diabetes (T2D), yet effective therapies to protect these cells from dysfunction are lacking. In this study, through a combination of islet single-cell data from independent cohorts and machine learning, we reveal zinc-induced integrated stress response (ISR) as a potential target for ß cell protection. Validating our findings with human embryonic stem cell-derived ß cells (SC-ß cells) and human primary islets, we confirm that inhibiting zinc transportation shields ß cells from exacerbated endoplasmic reticulum stress (ER stress) and concurrent integrated stress response (ISR). Mechanistically, our results discover that elevated zinc transportation exacerbates ER stress, promoting phosphorylation of the eukaryotic translation initiation factor 2 (eIF2a) subunit, thereby initiating ISR, enhancing stress granule formation, and ultimately leading to ß cell death as a pivotal pathomechanism for ß cell loss. Furthermore, through compound screening targeting zinc transportation with SC-ß cells, we discover that low-dose (nanomolar) anisomycin significantly inhibits zinc transportation, preventing ß cell loss from various stress-induced cell deaths. Significantly, in vivo administration of anisomycin in mice protects ß cells and prevents diabetes induced by streptozotocin (STZ) and type 2 diabetes (high-fat diet, HFD). Collectively, our findings highlight the potency of combining large-scale single-cell data, machine learning, human embryonic stem cell-derived cells, and compound screening to identify potential therapeutic molecules against complex diseases. Overall design: We generated hESCs reporter cell line (MEL1 Nkx6.1:linker2a:mCherry; INSGFP/w) that enable to precisely and dynamically trace SC-ß cells during differentiated stages. Meanwhile, WFS1 knockout hESCs reporter cell line (WFS1-/-) was established by using a CRISPR/Cas9 knock-out strategy to mimic severe mutations identified from WS patients. We performed single-cell RNA sequencing (scRNA-Seq) for WFS1-/- and WFS1-/- + Inh19 SC-islets by sorting out GFP and mCherry double-positive SC-ß cells with high INS and NKX6.1 expression