Quantitative assessment of mitochondrial membrane potential in macrophages in sepsis

Sepsis, a life-threatening condition characterized by dysregulated host response to infection, poses a significant public healthcare challenge. Excessive inflammatory responses during sepsis can lead to mitochondrial dysfunctions, resulting in organ damage. One hallmark of mitochondrial dysfunction is the reduction of mitochondrial membrane potential, which disrupts cellular metabolism, bioenergetics, and decreases the production of high-energy ATP through oxidative phosphorylation. In human sepsis, the mitochondrial membrane potential in peripheral blood monocytes has been identified as a marker of disease severity. Here, we present a detailed and widely accepted protocol for the detection of mitochondrial membrane potential using the JC-1 fluorescent dye in murine bone marrow-derived macrophages and J774A.1 macrophages following stimulation with lipopolysaccharides. This protocol is routinely employed and can be easily adapted for various cell types, intact tissues, and isolated mitochondria with minimal modifications. By utilizing this technique, researchers can gain valuable insights into mitochondrial function in different experimental contexts, potentially advancing our understanding of the pathogenesis and treatment of sepsis-related mitochondrial dysfunction.