Quantification of intracellular and mitochondrial ATP content in macrophages during lipopolysaccharide-induced...

Sepsis, a condition characterized by systemic infection that becomes aggravated and dysregulated, is a significant cause of mortality in critically ill patients. Emerging evidence suggests that severe sepsis is often accompanied by alterations in cell metabolism, particularly mitochondrial dysfunction, resulting in multiorgan failure. Normally, metabolically active cells or tissues exhibit higher levels of mitochondrial turnover, respiration, and adenosine triphosphate (ATP) synthesis. However, during sepsis, these processes become overwhelmed or dysregulated, leading to impaired ATP production in mitochondria. Here, we present two straightforward protocols for quantifying ATP production from mitochondria in bone marrow-derived macrophages (BMDMs). Our workflow facilitates the easy isolation of BMDMs and mitochondria from BMDMs treated with lipopolysaccharide (LPS), the major cell wall component of Gram-negative bacteria. We quantified intracellular and mitochondrial ATP production in macrophages in vitro using this protocol. The results indicated a decrease in mitochondrial ATP content in BMDMs in response to LPS. With minimal adjustments, this method can be adapted for use with various human and mouse primary cells and cell lines.