Nucleoside 5′-Phosphorothioate Derivatives as Oxidative Stress Protectants in PC12 Cells

Abstract

Iron-induced oxidative damage of mitochondria contributes to cellular death seen in neurodegenerative diseases, therefore, there is a demand for nontoxic, biocompatible, and effective Fe-ion chelators. We evaluated the chelation of Fe(II) by phosphate derivatives using ferrozine as an indicator. We studied the effect of phosphate derivatives on inhibiting Fe(II)-induced oxidative stress in PC12 cells, and metabolic stability in PC12 cells was evaluated. Nucleotides containing phosphorothioate moieties inhibited ROS formation better than natural nucleotides and were more metabolically stable in PC12 cells. Finally, we elucidated that these nucleotides activate the MAP-kinase pathway that contributes to protection of PC12 cells under oxidative stress.

Identification of Highly Promising Antioxidants/Neuroprotectants Based on Nucleoside 5′-Phosphorothioate Scaffold. Synthesis, Activity, and Mechanisms of Action

“…Specifically, we Fe(II)-chelators such as DTPA, Trolox, and citrate. 28 In that study we found that nucleoside-thiophosphate analogues were better Fe(II)-chelators vs. the corresponding natural nucleotides, e.g. IC 50 values of ADP-β-S and ADP were 85 and 250 µM, respectively vs. DTPA, Trolox, and citrate, 90, 150 and 300 µM, respectively.…”

ATP-γ-S-(α,β-CH2) protects against oxidative stress and amyloid beta toxicity in neuronal culture

“…Previously we also found that nucleotides containing phosphorothioate moieties inhibited ROS formation in Fe(II)-treated PC12 cells up to 300-fold better than natural nucleotides and were up to 4.5-fold more metabolically stable [9]. We identified ATP-g-S (Fig.…”

“…Determination of ROS production in cultured PC12 cells was performed according to our previous protocol [9]. Oxidation was initiated by the addition of FeSO 4 (0.16 mM) to the wells in the presence of nucleotide analogues at 0.2e200 mM.…”

“…We identified ATP-g-S (Fig. 1) as a highly potent antioxidant that inhibited Fe(II)-induced ROS production under Fenton reaction conditions, in both non-cellular and cellular system, IC 50 14 mM [8] and 180 nM [9], respectively.…”

“…We have shown that nucleotides modulate Fenton reaction in a concentration-dependent biphasic fashion [8]. In addition to natural nucleotides, we investigated a series of phosphate-modified nucleotides, dinucleotides, and inorganic phosphates, as potential biocompatible anti-oxidants in in-vitro and cellular systems [9]. The purine nucleotide scaffold contains metal binding sites at both the phosphate chain and purine ring (N7-nitrogen atom), and makes a natural divalent metal ion chelator [8].…”