In:
Science Signaling, American Association for the Advancement of Science (AAAS), Vol. 15, No. 716 ( 2022-01-11)
Abstract:
The essential micronutrient zinc regulates immune responses by affecting signaling pathways. In activated monocytes and macrophages, signaling networks mediate the metabolic reprogramming that meets the demands of participation in immune responses. Here, we demonstrated that cytoplasmic, bioavailable zinc was essential for promoting IL-1β production in activated human monocytes and macrophages downstream of glycolysis induced by the kinase-containing multiprotein complex mTORC1. The concentration of cytoplasmic zinc was determined by that of extracellular zinc, which was brought into cells through the zinc-specific importer Zip8. The abundance of Zip8 was increased in monocytes from patients with rheumatoid arthritis (RA), as well as in LPS-stimulated monocytes and macrophages from healthy individuals. The mTORC1-mediated phosphorylation of S6 kinase (S6K) was enhanced by zinc-mediated inhibition of PP2A, a phosphatase that targets S6K. As a result, IL-1β production was increased due to the activation of mTORC1-induced glycolysis. In monocytes of patients with RA, the expression of Zip8 and the zinc-inducible metallothionein isoform MT2A and the phosphorylation of S6K were enhanced compared with those of healthy controls. Furthermore, Zip8 expression correlated with more severe RA clinical parameters, suggesting that Zip8-mediated zinc influx is related to inflammatory conditions. These results provide insight into the role of cytoplasmic, bioavailable zinc in the metabolic reprogramming of human monocytes and macrophages in inflammatory responses.
Type of Medium:
Online Resource
ISSN:
1945-0877
,
1937-9145
DOI:
10.1126/scisignal.abi7400
Language:
English
Publisher:
American Association for the Advancement of Science (AAAS)
Publication Date:
2022
Permalink
