P2Y1 purinergic receptor identified as a diabetes target in a small-molecule screen to reverse circadian β-cell failure

Abstract

The mammalian circadian clock drives daily oscillations in physiology and behavior through an autoregulatory transcription feedback loop present in central and peripheral cells. Ablation of the core clock within the endocrine pancreas of adult animals impairs the transcription and splicing of genes involved in hormone exocytosis and causes hypoinsulinemic diabetes. Here, we developed a genetically sensitized small-molecule screen to identify druggable proteins and mechanistic pathways involved in circadian β-cell failure. Our approach was to generate β-cells expressing a nanoluciferase reporter within the proinsulin polypeptide to screen 2640 pharmacologically active compounds and identify insulinotropic molecules that bypass the secretory defect in CRISPR-Cas9-targeted clock mutant β-cells. We validated hit compounds in primary mouse islets and identified known modulators of ligand-gated ion channels and G-protein-coupled receptors, including the antihelmintic ivermectin. Single-cell electrophysiology in circadian mutant mouse and human cadaveric islets revealed ivermectin as a glucose-dependent secretagogue. Genetic, genomic, and pharmacological analyses established the P2Y1 receptor as a clock-controlled mediator of the insulinotropic activity of ivermectin. These findings identify the P2Y1 purinergic receptor as a diabetes target based upon a genetically sensitized phenotypic screen.

Circadian desynchrony and glucose metabolism

“…When activated, the P2Y1 receptor enhances glucosestimulated insulin secretion in human islets. 241 However, P2Y1 receptors are involved in platelet activation and aggregation, which may increase thrombosis risk. 242 The novel glucose-lowering oral drug Imeglimin, approved for use in type 2 diabetes patients in Japan in 2021, improves glucose regulation in type 2 diabetes patients by enhancement of glucose-stimulated insulin secretion from pancreatic beta-cells.…”

“…The P2Y1 receptor's role as a direct transcriptional target and potential drug target of the molecular clock factor BMAL1 is currently being unraveled. When activated, the P2Y1 receptor enhances glucose‐stimulated insulin secretion in human islets 241 . However, P2Y1 receptors are involved in platelet activation and aggregation, which may increase thrombosis risk 242 …”

Type I Diabetes Pathoetiology and Pathophysiology: Roles of the Gut Microbiome, Pancreatic Cellular Interactions, and the ‘Bystander’ Activation of Memory CD8+ T Cells

“…This would indicate that the pro-inflammatory cytokine-induced IDO-kynurenine-AhR activation, increasing NAS for TrkB-T1 (or TrkB-FL), may be providing pro-survival benefits under challenge, with released kynurenine, via AhR activation on CD8 + T cells, expected to suppress their cytolytic capacity. The three known inducers of NAS from melatonin, namely the AhR, P2Y1r, and mGluR5, can potentiate insulin release from pancreatic β-cells [ 125 , 126 ]. The activation of the cystine–glutamate antiporter (system χ c ) may be relevant to glutamate effects in pancreatic β- and α-cells, whereby the demand for GSH production will drive the release of glutamate, which can act on α-cells to activate the AMPA/kainate receptors, thereby enhancing glucagon responses in the prevention of hypoglycaemia [ 127 ].…”

Pharmacological and mechanistic study of PS1, a Pdia4 inhibitor, in β-cell pathogenesis and diabetes in db/db mice

“…Some potential molecular targets of β-cell failure have been identified including BACH2 [ 14 ], MST1 [ 15 ], GSK3 [ 16 ], PDX1 [ 16 ], P2RY1 [ 17 ], PHLPP [ 18 ], Pdia4 [ 2 ], etc. Among them, Pdia4 was the only target whose deficiency could reverse diabetes [ 2 ].…”