Macrophage Enzyme ALOXE3 Emerges as a Modulator of Acetaminophen Liver Injury

A new study published in Cell & Bioscience points to a specific enzyme in macrophages, arachidonate lipoxygenase 3, or ALOXE3, as a modulator of the oxidative stress that accompanies acetaminophen-induced liver injury.

The research team combined hepatic transcriptomic and proteomic datasets with untargeted metabolomics to identify candidate molecules worth functional testing. Joint pathway analysis of these layered data highlighted arachidonic acid metabolism as a pathway of interest. Within that pathway, ALOXE3 stood out because it was upregulated concordantly at both the mRNA and protein levels, and because the enzyme had previously been characterized as having hydroperoxide isomerase activity, a biochemical property plausibly relevant to redox balance in damaged tissue.

To establish where ALOXE3 acts, the investigators turned to spatial transcriptomics and single-cell transcriptomics. These approaches provided cellular context for Aloxe3 expression, including its detection in macrophage-associated populations within the injured liver. The single-cell analysis went a step further: macrophages that were positive for Aloxe3 showed higher scores for a gene set related to glutathione metabolism than macrophages that were negative for the enzyme. This pattern suggested that ALOXE3-positive macrophages differ from ALOXE3-negative macrophages with respect to glutathione metabolism-related gene expression.

The functional tests were carried out in vivo using macrophage-directed manipulation of ALOXE3. When the enzyme was overexpressed in macrophages, mice with acetaminophen-induced liver injury showed reduced serum alanine aminotransferase and aspartate aminotransferase activities, standard biochemical markers of liver damage, along with reduced hepatic necrosis on histological assessment. Knockdown of ALOXE3 produced the opposite effects, worsening both the enzyme markers and the necrotic damage.

The authors also probed the mechanism in isolated bone marrow-derived macrophages exposed to conditioned medium from acetaminophen-treated hepatocytes. In this cell-culture setting, ALOXE3 knockdown increased signals for 4-hydroxynonenal, a lipid peroxidation product, and increased reactive oxygen species-associated fluorescence, while reducing glutathione-associated fluorescence. Overexpression of the enzyme produced the opposite changes in all three readouts. Together, these experiments link macrophage ALOXE3 to the handling of oxidative stress signals in an inflammatory environment generated by injured hepatocytes.

The study’s design is notable for its multi-omics triage strategy. Rather than testing a single hypothesis, the authors used untargeted metabolomics to capture the metabolic landscape of the injured liver, then cross-referenced those findings with transcriptomic and proteomic measurements to prioritize ALOXE3. Only after this convergence of evidence did they move to spatial and single-cell mapping and, finally, to gain- and loss-of-function experiments. This sequence helps ensure that the functional work targeted a molecule with independent lines of supporting data rather than a purely correlative hit.

Several limitations should be kept in view. The in vivo evidence comes from macrophage-directed manipulation in animal models of acetaminophen injury, and the mechanistic cell experiments rely on conditioned medium rather than the full complexity of injured liver tissue. The abstract reports that these findings support a role for macrophage ALOXE3 in redox responses during acetaminophen-induced liver injury; it does not establish the enzyme as a therapeutic target in patients, and no clinical data are presented. The article is also being shared early as a peer-reviewed accepted manuscript, subject to further edits before the final version of record.

For now, the contribution is mechanistic: a prioritized enzyme, a defined cellular population and a set of redox markers that future studies can interrogate in greater depth.

Subject of Research: The role of the macrophage enzyme ALOXE3 in oxidative stress during acetaminophen-induced liver injury

Article Title: Integrated metabolomic and expression analyses identify macrophage ALOXE3 as a modulator of oxidative stress in acetaminophen-induced liver injury

Article References: Liu, Y., Gao, H., Weng, C., Jiang, Q., Lv, Y., Wang, F., Ma, J., He, J., & Lin, J. (2026). Integrated metabolomic and expression analyses identify macrophage ALOXE3 as a modulator of oxidative stress in acetaminophen-induced liver injury. Cell & Bioscience. https://doi.org/10.1186/s13578-026-01672-2

Image Credits: AI Generated

DOI: 10.1186/s13578-026-01672-2

Keywords: acetaminophen, liver injury, macrophages, ALOXE3, oxidative stress, glutathione, metabolomics, single-cell transcriptomics, arachidonic acid, 4-hydroxynonenal, Integrated, metabolomic