Mitochondrial Dysfunction in Apoptosis-Resistant Acute Myeloid Leukemia Cells During a Sterile Inflammatory Response

Mitochondria are crucial for energy metabolism and the regulation of apoptosis and the inflammatory response in acute myeloid leukemia (AML). This study examined key mitochondrial characteristics in apoptosis-resistant AML cells during in vitro aseptic pro-inflammatory activation utilizing spectrofluorimetry, quantitative reverse transcription PCR, Western blotting, differential gene expression analysis, flow cytometry, transmission electron microscopy, and cellular respiration analysis. Under conditions of aseptic inflammation simulated in three-dimensional high-density cultures, apoptosis-resistant AML cells exhibited a significant reduction in the transcriptional activity of genes linked to oxidative phosphorylation and the tricarboxylic acid cycle; demonstrated diminished mitochondrial respiration activity; and decreased levels of the mitophagy regulatory proteins PINK1 and Parkin. Furthermore, pathogenic alterations in mitochondrial morphology were observed. These cells demonstrated enhanced intracellular generation of reactive oxygen species, lactate accumulation in the culture media, elevated levels of DRP1 protein, and an increased fraction of small and medium-sized mitochondria. The acquired data demonstrate that aseptic pro-inflammatory activation results in metabolic remodelling of acute myeloid leukemia cells, integrating characteristics of mitochondrial dysfunction. This condition may facilitate the persistence of leukemic cells during inflammatory stress and potentially contribute to the development of an apoptosis-resistant phenotype. The established in vitro model is crucial for examining both the characteristics of energy metabolism and the anti-apoptotic mechanisms in leukemic cells.