It was hypothesized that the catalyst nanoceria can increase oxidative

stress/inflammation from the basal state and reduce it from the elevated state .

Nanoceria are cleared by macrophages. To test the hypothesis, M0 (non-polarized),

M1- (classically activated, pro-inflammatory), and M2-like (alternatively activated,

regulatory phenotype) RAW 264.7 macrophages were nanoceria exposed. Responses

were quantified by arginase activity, IL-1ß level, cell oxygen consumption rate (OCR),

the glycolysis stress test (GST), morphology determined by light microscopy,

macrophage phenotype marker expression and morphology using a novel three

dimensional immunohistochemical method, and RT-qPCR. Nanoceria blocked

arginase and IL-1ß effects, increased M0 cell OCR and GST toward the M2 phenotype

and altered multiple M1- and M2-like cell endpoints toward the M0 level. M1-like cells

had greater volume and less circularity/roundness, and the M2-like cells had greater

volume than M0 macrophages. Nanoceria converted M1- and M2-like cells toward M0

morphology. The results are overall consistent with the hypothesis.

Document Type


Publication Date


Digital Object Identifier (DOI)


Funding Information

This work was supported by the National Institutes of Health [grant number R01GM109195]. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health