biostudies-literatureMendel ZIUniversity of MichiganNIAID NIH HHSNational Institutes of HealthNIH HHSNIGMS NIH HHSjcs259284https://www.ebi.ac.uk/biostudies/studies/S-EPMC8919328biostudies-literatureUnknown135(4)The internalization of solutes by macropinocytosis provides an essential route for nutrient uptake in many cells. Macrophages increase macropinocytosis in response to growth factors and other stimuli. To test the hypothesis that nutrient environments modulate solute uptake by macropinocytosis, this study analyzed the effects of extracellular amino acids on the accumulation of fluorescent fluid-phase probes in murine macrophages. Nine amino acids, added individually or together, were capable of suppressing macropinocytosis in murine bone marrow-derived macrophages stimulated with the growth factors colony stimulating factor 1 (CSF1) or interleukin 34, both ligands of the CSF1 receptor (CSF1R). The suppressive amino acids did not inhibit macropinocytosis in response to lipopolysaccharide, thJournal of cell scienceAmino acids suppress macropinocytosis and promote release of CSF1 receptor in macrophages.PMC8919328R01GM101189R35GM131720R01GM110215T32 GM008353T32GM008353R35 GM131720R21AI135403T32AI007413R01 AI157384T32 AI007413R21 AI135403Mendel ZIAbuaita BHReynolds MBO'Riordan MXSwanson JAfalseAmino acids suppress macropinocytosis and promote release of CSF1 receptor in macrophages.The internalization of solutes by macropinocytosis provides an essential route for nutrient uptake in many cells. Macrophages increase macropinocytosis in response to growth factors and other stimuli. To test the hypothesis that nutrient environments modulate solute uptake by macropinocytosis, this study analyzed the effects of extracellular amino acids on the accumulation of fluorescent fluid-phase probes in murine macrophages. Nine amino acids, added individually or together, were capable of suppressing macropinocytosis in murine bone marrow-derived macrophages stimulated with the growth factors colony stimulating factor 1 (CSF1) or interleukin 34, both ligands of the CSF1 receptor (CSF1R). The suppressive amino acids did not inhibit macropinocytosis in response to lipopolysaccharide, th2022-01-01T00:00:00Z2022 Feb2025-04-04T14:50:35.207Z2025-04-04T14:50:35.207ZS-EPMC89193283510713310.1242/jcs.259284