Plant Polyphenol Gossypol Induced Cell Death and Its Associ-ation with Gene Expression in Mouse Macrophages

Abstract

Gossypol is a complex plant polyphenol reported to be cytotoxic and anti-inflammatory, but little was known about its effect on gene expression in macrophages. The objective was to explore gossypol’s toxicity and its effect on gene expression involved in inflammatory responses, glucose transport and insulin signaling pathway in mouse macrophages. Mouse RAW264.7 macrophages were treated with multiple concentrations of gossypol for 2-24 h. Gossypol toxicity was estimated by MTT assay and soluble protein content. qPCR analyzed the expression of anti-inflammatory tristetraprolin family (TTP/ZFP36), proinflammatory cytokine, glucose transporter (GLUT) and insulin signaling genes. Cell viability was greatly reduced by gossypol, accompanied with dra-matic reduction of soluble protein content in the cells. Gossypol treatment resulted in an increase of TTP mRNA level 6-20 fold and increased ZFP36L1, ZFP36L2 and ZFP36L3 mRNA levels by 26-69 fold. Gossypol increased proinflammatory cytokine TNF, COX2, GM-CSF, INFγ and IL12b mRNA levels up to 39-458 fold. Gossypol treatment upregulated mRNA levels of GLUT1, GLUT3 and GLUT4 genes as well as INSR, AKT1, PIK3R1 and LEPR but not APP genes. This study demonstrated that gossypol induced macrophage death and reduced soluble protein content that was accom-panied with massive stimulation of anti-inflammatory TTP family and proinflammatory cytokine gene expression as well as elevation of gene expression involved in glucose transport and insulin signaling pathway in mouse macrophages.