Development of an iron-selective antioxidant probe with protective effects on neuronal function

PLoS One. 2017 Dec 11;12(12):e0189043. doi: 10.1371/journal.pone.0189043. eCollection 2017.

Abstract

Iron accumulation, oxidative stress and calcium signaling dysregulation are common pathognomonic signs of several neurodegenerative diseases, including Parkinson´s and Alzheimer's diseases, Friedreich ataxia and Huntington's disease. Given their therapeutic potential, the identification of multifunctional compounds that suppress these damaging features is highly desirable. Here, we report the synthesis and characterization of N-(1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl)-2-(7-hydroxy-2-oxo-2H-chromen-4-yl)acetamide, named CT51, which exhibited potent free radical neutralizing activity both in vitro and in cells. CT51 bound Fe2+ with high selectivity and Fe3+ with somewhat lower affinity. Cyclic voltammetric analysis revealed irreversible binding of Fe3+ to CT51, an important finding since stopping Fe2+/Fe3+ cycling in cells should prevent hydroxyl radical production resulting from the Fenton-Haber-Weiss cycle. When added to human neuroblastoma cells, CT51 freely permeated the cell membrane and distributed to both mitochondria and cytoplasm. Intracellularly, CT51 bound iron reversibly and protected against lipid peroxidation. Treatment of primary hippocampal neurons with CT51 reduced the sustained calcium release induced by an agonist of ryanodine receptor-calcium channels. These protective properties of CT51 on cellular function highlight its possible therapeutic use in diseases with significant oxidative, iron and calcium dysregulation.

MeSH terms

  • Antioxidants / metabolism*
  • Calcium Signaling
  • Cell Line, Tumor
  • Humans
  • Iron / metabolism*
  • Neurons / metabolism
  • Neurons / physiology*
  • Oxidative Stress

Substances

  • Antioxidants
  • Iron

Grants and funding

This study was supported by the Comisión Nacional de Investigación Científica y Tecnológica (CONICYT), Chile (http://spl.conicyt.cl/auth/), which provided a postdoctoral research grant (N° 3149451) to Dr. Olimpo García-Beltrán; Fondo Nacional de Desarrollo Científico y Tecnológica (FONDECYT), Chile (http://www.conicyt.cl/fondecyt/), which provided research grants to Cecilia Hidalgo (N° 1149545), Marco T. Núñez (N° 1130068) and Tatiana Adasme (N° 11140580); Instituto de Neurociencia Biomédica, Iniciativa Científica Milenio, Chile (www.iniciativamilenio.cl/), which provided research funds to Cecilia Hidalgo (N° BNI P-09-015F). Financial support to Prof. Marco T Núñez was provided by the Program for Research, Faculty of Sciences (PAIFAC) and by U-APOYA 2236, VID, Universidad de Chile. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.