W2476 ameliorates β-cell dysfunction and exerts therapeutic effects in mouse models of diabetes via modulation of the thioredoxin-interacting protein signaling pathway

Acta Pharmacol Sin. 2017 Jul;38(7):1024-1037. doi: 10.1038/aps.2017.15. Epub 2017 May 15.

Abstract

Recent evidence shows that high glucose levels recruit carbohydrate response element-binding protein, which binds the promoter of thioredoxin-interacting protein (txnip), thereby regulating its expression in β-cells. Overexpression of txnip not only induces β-cell apoptosis but also reduces insulin production. Thus, the discovery of compounds that either inhibit TXNIP activity or suppress its expression was the focus of the present study. INS-1E cells stably transfected with either a txnip proximal glucose response element connected to a luciferase reporter plasmid (BG73) or full-length txnip promoter connected to a luciferase reporter plasmid (CL108) were used in primary and secondary high-throughput screening campaigns, respectively. From 256 000 synthetic compounds, a small molecule compound, W2476 [9-((1-(4-acetyl-phenyloxy)-ethyl)-2-)adenine], was identified as a modulator of the TXNIP-regulated signaling pathway following the screening and characterized using a battery of bioassays. The preventive and therapeutic properties of W2476 were further examined in streptozotocin-induced diabetic and diet-induced obese mice. Treatment with W2476 (1, 5, and 15 μmol/L) dose-dependently inhibited high glucose-induced TXNIP expression at the mRNA and protein levels in INS-1E cells and rat pancreatic islets. Furthermore, W2476 treatment prevented INS-1E cells from apoptosis induced by chronic exposure of high glucose and enhanced insulin production in vitro. Oral administration of W2476 (200 mg·kg-1·d-1) rescued streptozotocin-induced diabetic mice by promoting β-cell survival and enhancing insulin secretion. This therapeutic property of W2476 was further demonstrated by its ability to improve glucose homeostasis and insulin sensitivity in diet-induced obese mice. Thus, chemical intervention of the TXNIP-regulated signaling pathway might present a viable approach to manage diabetes.

MeSH terms

  • 3T3-L1 Cells
  • Adenine / administration & dosage
  • Adenine / analogs & derivatives*
  • Adenine / chemistry
  • Adenine / pharmacology
  • Administration, Oral
  • Animals
  • Carrier Proteins / antagonists & inhibitors*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Cell Cycle Proteins
  • Cells, Cultured
  • Diabetes Mellitus, Experimental / chemically induced
  • Diabetes Mellitus, Experimental / drug therapy*
  • Disease Models, Animal*
  • Dose-Response Relationship, Drug
  • Insulin / metabolism
  • Insulin-Secreting Cells / drug effects*
  • Insulin-Secreting Cells / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Molecular Structure
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects*
  • Streptozocin
  • Structure-Activity Relationship
  • Thioredoxins / antagonists & inhibitors*
  • Thioredoxins / genetics
  • Thioredoxins / metabolism

Substances

  • 9-((1-(4-acetyl-phenyloxy)-ethyl)-2-)adenine
  • Carrier Proteins
  • Cell Cycle Proteins
  • Insulin
  • TXNIP protein, rat
  • Txnip protein, mouse
  • Thioredoxins
  • Streptozocin
  • Adenine