Single-cell RNA sequencing reveals a role for reactive oxygen species and peroxiredoxins in fatty-acid-induced rat β-cell proliferation

The functional mass of insulin-secreting pancreatic {beta} cells expands to maintain glucose homeostasis in the face of nutrient excess, in part via replication of existing {beta} cells. To decipher the underlying molecular mechanisms, we assessed {beta}-cell proliferation in isolated rat islets exposed to glucose and oleate or palmitate for 48 h and analyzed the transcriptional response by single-cell RNA sequencing. Unsupervised clustering of pooled {beta} cells identified subpopulations, including proliferating {beta} cells. {beta}-cell proliferation increased in response to oleate but not palmitate. Both fatty acids enhanced the expression of genes involved energy metabolism and mitochondrial activity. Comparison of proliferating vs. non-proliferating {beta} cells and pseudotime ordering suggested the involvement of reactive oxygen species (ROS) and peroxiredoxin signaling. Accordingly, the antioxidant N-acetyl cysteine and the peroxiredoxin inhibitor Conoidin A both blocked oleate-induced {beta}-cell proliferation. Our data reveal a key role for ROS signaling in {beta}-cell proliferation in response to nutrients.