In:
Antioxidants, MDPI AG, Vol. 12, No. 9 ( 2023-08-30), p. 1689-
Abstract:
The detection of superoxide anion (O2●−) in biological tissues remains challenging. Barriers to convenient and reproducible measurements include expensive equipment, custom probes, and the need for high sensitivity and specificity. The luminol derivative, L-012, has been used to measure O2●− since 1993 with mixed results and concerns over specificity. The goal of this study was to better define the conditions for use and their specificity. We found that L-012 coupled with depolymerized orthovanadate, a relatively impermeable tyrosine phosphatase inhibitor, yielded a highly sensitive approach to detect extracellular O2●−. In O2●− producing HEK-NOX5 cells, orthovanadate increased L-012 luminescence 100-fold. The combination of L-012 and orthovanadate was highly sensitive, stable, scalable, completely reversed by superoxide dismutase, and selective for O2●− generating NOXes versus NOX4, which produces H2O2. Moreover, there was no signal from cells transfected with NOS3 (NO●) and NOS2(ONOO−). To exclude the effects of altered tyrosine phosphorylation, O2●− was detected using non-enzymatic synthesis with phenazine methosulfate and via novel coupling of L-012 with niobium oxalate, which was less active in inducing tyrosine phosphorylation. Overall, our data shows that L-012 coupled with orthovanadate or other periodic group 5 salts yields a reliable, sensitive, and specific approach to measuring extracellular O2●− in biological systems.
Type of Medium:
Online Resource
ISSN:
2076-3921
DOI:
10.3390/antiox12091689
Language:
English
Publisher:
MDPI AG
Publication Date:
2023
detail.hit.zdb_id:
2704216-9
SSG:
15,3
Permalink
