ABSTRACT The Gal/GalNAc lectin in Entamoeba histolytica is pivotal for its pathogenicity, and its intermediate subunit (Igl) is a crucial virulence factor. Here, the interference of eukaryotically expressed Igl on normal metabolic processes within Caco-2 cells was explored. Targeted metabolomic analysis detected 232 metabolites in Caco-2 cells, revealing 63 with significant alterations after Igl treatment. Notably, the lactate content significantly increased, indicating that Igl activates aerobic glycolysis. Metabolic flux analysis demonstrated that Igl could inhibit aerobic respiration and the tricarboxylic acid cycle in host cells. It significantly increased glucose intake, lactate production, and ATP generation, demonstrating its ability to induce a Warburg-like effect. Through single-cell transcriptomic experiments, significant increases in changes were observed in 4 out of 12 individual host cell groups after Igl treatment. Group marker genes identified these cell groups as having inhibited aerobic respiration and activated stress responses, further indicating that Igl stimulation can affect the aerobic respiration and normal metabolic processes of cells. Additionally, RNA interference experiments were performed to verify the effect of Igl on host cell autophagy when PRKAA1 was silenced. Confocal microscopy and western blotting revealed significantly enhanced autophagy signals after Igl treatment, and it was confirmed that mammalian target of rapamycin was involved in this process. These results indicate that Igl induces metabolic reprogramming and a Warburg-like shift in host epithelial cells, thereby activating aerobic glycolysis and regulating host cell autophagy. This represents a novel mechanism of Igl in the pathogenicity of E. histolytica . IMPORTANCE Entamoeba histolytica causes amoebiasis, an infection manifesting as colitis and extraintestinal abscesses. Multi-omics approaches provide critical insights into the role of the Gal/GalNAc lectin intermediate subunit (Igl) within host cells, offering a foundation for developing effective treatments. Our findings indicate that Igl induces metabolic reprogramming in host epithelial cells. Specifically, Igl can trigger a Warburg-like shift, a phenomenon characterized by the activation of aerobic glycolysis. This shift results in increased glucose intake, lactate production, and ATP generation while inhibiting aerobic respiration and the tricarboxylic acid cycle. Furthermore, Igl regulates host cell autophagy, a process further confirmed through RNA interference experiments targeting PRKAA1 , which revealed the involvement of mammalian target of rapamycin. Taken together, our data suggest that Igl promotes trophozoite virulence through a novel mechanism that involves metabolic reprogramming and a Warburg-like shift in host cells.
Zhao et al. (Wed,) studied this question.