Low pH modulates lipopolysaccharide-induced tumor necrosis factor-alpha expression and macropinocytotic activity in RAW264.7 cells.

Autor:	Otsugu M; Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan., Mine A; Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan., Uchida I; Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan., Miyake Y; Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan., Tachihara R; Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan., Fujiwara K; Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan., Ichimura A; Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan., Sato K; Laboratory of Signal Transduction, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan., Tomura H; Laboratory of Cell Signaling Regulation, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan.; Institute of Endocrinology, Meiji University, Kawasaki, Japan.
Jazyk:	angličtina
Zdroj:	Journal of receptor and signal transduction research [J Recept Signal Transduct Res] 2024 Apr; Vol. 44 (2), pp. 63-71. Date of Electronic Publication: 2024 Aug 22.
DOI:	10.1080/10799893.2024.2395310
Abstrakt:	Inflammation triggers various types of diseases that need to be addressed. Macrophages play important roles in the inflammatory responses. As atherosclerosis progresses, macrophages transform into foam cells. Extracellular acidification is observed at and around bacterial infection and atherosclerotic sites. However, the effects of acidification on the inflammatory response of macrophages and the progression of atherosclerosis have not been fully understood. This study investigates the impact of extracellular acidification on lipopolysaccharide-induced tumor necrosis factor-alpha (TNF-α) expression and macropinocytotic activity in RAW264.7 cells. TNF-α expression is measured by real-time polymerase chain reaction (relative value to glyceraldehyde-3-phosphate dehydrogenase expression). Macropinocytotic activity is measured by neutral red uptake (absorbance at 540 nm). Results show that TNF-α expression increased with decreasing extracellular pH in both un-foamed and foamed cells. Macropinocytotic activity was upregulated at pH 6.8 in un-foamed cells, but downregulated in foamed cells stimulated at low pH. Proton-sensing G protein-coupled receptors (GPCRs) were involved in the expression of TNF-α and in the macropinocytotic activity of foamed cells. In conclusion, this study reveals that extracellular acidification differently affect various inflammatory responses such as LPS-induced TNF-α expression and macropinocytotic activity of RAW264.7 cells and different proton-sensing GPCRs are involved in the different inflammatory responses.
Databáze:	MEDLINE
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