Plant polyphenol gossypol induced cell death and its association with gene expression in mouse macrophages

Authors: Cao, Heping; Sethumadhavan, Kandan

Submitted to: Biomolecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/27/2023
Publication Date: 3/30/2023
Citation: Cao, H., Sethumadhavan, K. 2023. Plant polyphenol gossypol induced cell death and its association with gene expression in mouse macrophages. Biomolecules. 13(4). Article 624. https://doi.org/10.3390/biom13040624.
DOI: https://doi.org/10.3390/biom13040624

Interpretive Summary: Plant functional foods and derived compounds that can upregulate TTP gene expression may have nutritional and therapeutic value for the prevention and/or treatment of inflammation-related diseases. TTP gene expression can be increased by plant nutrient zinc and plant polyphonol extracts from cinnamon bark and green tea leaves. Gossypol is a complex polyphenol with anti-inflammatory activity. It was unknown whether gossypol can regulate TTP family gene expression. The objective of this study was to explore the molecular effects of gossypol on the expression of TTP family genes and compared the effects of gossypol to LPS in mouse RAW264.7 macrophages. This study demonstrated that gossypol was a strong stimulator of TTP family gene expression in macrophages and that unlike LPS, gossypol effects were sustained over time. These results suggest that gossypol may have health and nutritional benefits for inflammation-related diseases.

Technical 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 dramatic 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, INF' 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 accompanied 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.