Chronic Intermittent Hypoxia-Induced Diaphragm Muscle Weakness Is NADPH Oxidase-2 Dependent.

Area of Science:

• Physiology
• Molecular Biology
• Respiratory Medicine

Background:

• Chronic intermittent hypoxia (CIH) leads to diaphragm muscle dysfunction through redox alterations.
• The specific role of NADPH oxidase 2 (NOX2) in CIH-induced diaphragm dysfunction remains unclear.

Purpose of the Study:

• To investigate if NOX2-derived reactive oxygen species (ROS) mediate CIH-induced diaphragm muscle dysfunction.
• To assess the therapeutic potential of NOX2 inhibition in preventing CIH-induced diaphragm weakness.

Main Methods:

• Adult male mice were exposed to CIH for 14 days.
• Mice received either a NOX2 inhibitor (apocynin) or were genetically deficient in NOX2 (NOX2-null).
• Diaphragm muscle performance and gene expression were analyzed.

Main Results:

• Apocynin treatment and NOX2 deletion completely prevented CIH-induced diaphragm muscle dysfunction.
• CIH exposure increased NOX4 mRNA but not NOX2 expression.
• A NOX2-dependent upregulation of genes involved in muscle regeneration, antioxidant capacity, autophagy, and atrophy was observed.

Conclusions:

• NOX2-derived ROS play a critical role in CIH-induced diaphragm muscle dysfunction.
• NOX2 blockade is a promising therapeutic strategy for improving diaphragm performance in conditions like obstructive sleep apnea.