GSR Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population of near-haploid human HAP1 cells featuring disruption of the GSR gene, which encodes glutathione reductase. This knockout model abolishes glutathione reductase activity, preventing the NADPH-dependent reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH). The resulting pool of edited cells serves as a versatile tool for investigating cellular redox homeostasis and oxidative stress responses.
The HAP1 cell line is a chronic myeloid leukemia-derived fibroblast-like cell line with a near-haploid karyotype, originally derived from the KBM-7 line. Its haploid nature simplifies genetic analysis and facilitates the generation of knockouts with unambiguous loss-of-function phenotypes. These adherent cells are widely used as a robust model system for functional genomics, drug screening, and pathway dissection.
Glutathione reductase (GSR) is a central enzyme in glutathione metabolism, maintaining intracellular reduced glutathione (GSH) pools essential for detoxifying reactive oxygen species and regulating redox-sensitive signaling. GSR functions downstream of NRF2 and reactive oxygen species (ROS) and interacts with glutaredoxin, NADPH, and GSSG. Through its activity, GSR supports downstream targets including glutathione peroxidases and glutathione S-transferases, and influences redox-sensitive proteins involved in cell survival and proliferation. The GSR-mediated reduction of GSSG is a critical step in the pentose phosphate pathway-NADPH and thioredoxin systems, linking metabolic flux to antioxidant defense.
In the HAP1 background, disruption of GSR leads to accumulation of oxidized glutathione, depletion of reduced GSH, and severe impairment of the cellular redox balance. These polyclonal knockout cells exhibit increased sensitivity to oxidative challenge, providing a physiologically relevant model for studying diseases associated with glutathione reductase deficiency, hemolytic anemia, and oxidative stress-related tissue damage. The near-haploid genome ensures that disruption of the single GSR allele results in a complete loss of enzyme function at the protein level, although as a polyclonal population, residual GSR activity may be present in a minority of cells.
This knockout model is ideally suited for investigating mechanisms of oxidative stress adaptation, redox signaling, and antioxidant pathway regulation. Typical applications include assessing cell viability under peroxide or electrophile stress, measuring the GSH/GSSG ratio, quantifying ROS production by flow cytometry, and evaluating apoptosis induction. The cells also facilitate drug toxicity and resistance studies, particularly for chemotherapeutics that generate oxidative damage. Researchers can confirm knockout via western blotting for GSR protein and RT-qPCR for mRNA expression. For detailed product information, customization options, or technical support, please contact Ascent Research.
