Glucose modulates cell death due to normobaric hyperoxia by maintaining cellular ATP

Area of Science:

• Cell Biology
• Biochemistry
• Toxicology

Background:

• Hyperoxia (95% O2) can induce cell death in cultured cells.
• The precise mechanisms driving hyperoxic cell death remain under investigation.
• Glucose metabolism is crucial for cellular energy production and survival.

Purpose of the Study:

• To investigate whether glucose depletion is a primary driver of cell death under hyperoxic conditions.
• To determine the role of glucose availability in protecting lung epithelial cells from hyperoxia-induced damage.

Main Methods:

• Cultured human lung epithelial-like cells (A549) were exposed to hyperoxia (95% O2) with varying initial medium volumes to control glucose depletion rates.
• Cells were either supplemented with glucose regularly or received no supplementation.
• Cell death was assessed by measuring lactate dehydrogenase (LDH) release and adenosine triphosphate (ATP) levels.
• Extracellular pH was monitored.

Main Results:

• Hyperoxic cell death, indicated by increased LDH activity, occurred only after glucose depletion in the medium.
• Cells exposed to hyperoxia without glucose supplementation showed rapid ATP loss and significant LDH release.
• Continuous glucose supplementation prevented cell death and LDH release, even with significant fermentation and acidic extracellular pH (pH 6.5).

Conclusions:

• Glucose depletion, rather than hyperoxia alone, is a critical determinant of cell death in A549 cells under hyperoxic conditions.
• Maintaining adequate glucose levels is essential for cell survival during hyperoxia.
• Targeting glucose metabolism could be a therapeutic strategy to mitigate hyperoxic injury.