Obstructive sleep apnea (OSA) is a prevalent sleep-disordered breathing condition characterized by recurrent collapse of the upper airway during sleep. Consequently, patients experience repeated cycles of oxygen desaturation followed by reoxygenation, a hallmark phenomenon known as chronic intermittent hypoxia (CIH). While sleep apnea primarily triggers daytime somnolence and neurocognitive deficits, systemic exposure to intermittent hypoxia inflicts widespread tissue damage across multiple organ systems. Specifically, the lungs suffer extensive structural impairment, oxidative distress, and inflammatory cascades due to repetitive hypoxic reoxygenation stress. Furthermore, accumulating evidence indicates that cellular death pathways drive the progression of pulmonary parenchymal degradation in chronic hypoxia. Understanding the precise molecular mechanisms governing lung injury under intermittent hypoxic conditions remains a critical priority for clinical pulmonology. Recently, researchers have turned their attention toward ferroptosis, a newly characterized form of regulated cell death. Investigating targeted molecular interventions, such as natural polyphenols, offers promising therapeutic horizons for preventing hypoxia-induced pulmonary degradation. In this context, exploring how resveratrol ferroptosis lung injury dynamics operate provides vital mechanistic insights into obstructive sleep apnea pathophysiology.

Mechanistic Role of Resveratrol Ferroptosis Lung Injury Pathways

Ferroptosis is an iron-dependent, non-apoptotic form of cell death driven by toxic lipid peroxidation and metabolic dysregulation. Unlike classical apoptosis or necrosis, ferroptosis directly stems from severe oxidative inactivation of intracellular antioxidant defense mechanisms. Glutathione peroxidase 4 (GPX4) serves as the primary enzymatic defender against lipid hydroperoxides within cellular membranes. When chronic intermittent hypoxia depletes intracellular glutathione (GSH) synthesis, GPX4 activity declines rapidly. As a result, excessive reactive oxygen species (ROS) accumulate alongside unsequestered ferrous iron, instigating unmitigated lipid peroxidation. In alveolar epithelial cells, this cascade compromises membrane integrity, triggers mitochondrial shrinkage, and induces dense membrane condensation. Recent experimental findings confirm that chronic intermittent hypoxia significantly heightens ferroptotic markers within lung parenchyma. Sprague-Dawley rat models and human bronchial epithelial cells subjected to cyclic hypoxia display marked structural collapse of alveolar walls and depleted glutathione pools. Fortunately, therapeutic administration of resveratrol effectively attenuates these pathological changes. By suppressing iron-dependent oxidative stress, resveratrol preserves mitochondrial morphology and stabilizes bronchial epithelial architecture during severe hypoxic cycles.

SIRT1 Activation Drives Cellular Defense Mechanisms

Sirtuin 1 (SIRT1) is an NAD+-dependent class III histone deacetylase that functions as a master regulator of metabolic homeostasis and stress resistance. Under severe hypoxic stress, intracellular SIRT1 signaling frequently becomes blunted, leaving lung tissues vulnerable to oxidative challenge. Resveratrol, a natural polyphenolic compound found in grapes and berries, is a well-established pharmacological activator of SIRT1. When administered during chronic intermittent hypoxia exposure, resveratrol restores SIRT1 activity back to physiological levels. Elevated SIRT1 orchestrates a downstream cascade that restores cellular redox homeostasis and prevents lipid oxidative damage. Furthermore, transcriptomic profiling combined with specialized bioinformatic analyses revealed that SIRT1 directly influences downstream transcription factors governing iron and amino acid metabolism. Specifically, rescue experiments involving SIRT1 overexpression demonstrated robust protection against ferroptotic cell death in bronchial epithelial cells. Conversely, genetic inhibition of SIRT1 completely abolished the protective antioxidants conferred by resveratrol administration. Therefore, SIRT1 activation serves as the fundamental molecular switch through which resveratrol exerts its protective downstream actions.

Transcriptional Regulation Through the EGR1 and GLS2 Cascade

To decipher how SIRT1 suppresses ferroptotic cascades, integrated RNA sequencing and database analyses targeted early growth response factor 1 (EGR1). EGR1 acts as a pivotal downstream transcriptional effector modulated directly by SIRT1 activation. Under resveratrol treatment, activated SIRT1 upregulates EGR1 expression within pulmonary tissues exposed to intermittent hypoxia. Subsequently, EGR1 binds directly to the promoter region of glutaminase 2 (GLS2), activating its transcription as confirmed by dual-luciferase reporter assays. GLS2 plays an essential regulatory role in cellular glutamine metabolism and intracellular glutathione biosynthesis. Upregulated GLS2 enhances the intracellular synthesis of GSH, which subsequently provides the necessary substrate for GPX4 enzymatic activity. Consequently, GPX4 efficiently neutralizes toxic lipid hydroperoxides, halting the execution of ferroptosis. Functional knockdown experiments confirm that silencing either EGR1 or GLS2 completely abrogates the anti-ferroptotic efficacy of resveratrol. Conversely, overexpressing GLS2 directly augments GSH production, protecting lung tissues against severe hypoxia-induced injury.

Translational Implications for Obstructive Sleep Apnea Therapeutics

Obstructive sleep apnea affects millions worldwide, yet current management primarily relies on continuous positive airway pressure (CPAP) devices. Although CPAP effectively restores physical airway patency during sleep, patient adherence remains suboptimal across global populations. Consequently, many individuals experience ongoing intermittent hypoxia, leading to persistent pulmonary vascular and parenchymal damage. The identification of resveratrol-mediated ferroptosis inhibition provides an exciting adjunct therapeutic strategy for obstructive sleep apnea. By directly targeting the SIRT1/EGR1/GLS2 molecular pathway, natural or synthetic SIRT1 activators could potentially shield pulmonary tissues from hypoxic degradation. Furthermore, protecting bronchial epithelial integrity reduces secondary inflammatory cascades and systemic vascular complications associated with sleep apnea. While present findings stem from rigorous preclinical rat models and human cell lines, they lay a strong scientific foundation for future human clinical trials. As research progresses, translating targeted anti-ferroptotic interventions into clinical practice may revolutionize pulmonary preservation strategies for patients suffering from severe sleep-disordered breathing.

Summary of Molecular Pathways in Hypoxia-Induced Lung Injury

In summary, chronic intermittent hypoxia induces profound pulmonary damage through the activation of ferroptosis, characterized by GSH depletion and GPX4 downregulation. Resveratrol intervention successfully reverses these damaging cellular phenotypes by activating the SIRT1-dependent signaling axis. Through this mechanism, SIRT1 upregulates EGR1 transcription, which subsequently binds and activates the GLS2 promoter to enhance glutathione synthesis. The boosted GSH levels empower GPX4 to eliminate harmful lipid peroxides, thereby preserving bronchial epithelial structural integrity. This comprehensive mechanistic framework highlights ferroptosis as a major pathophysiological driver in obstructive sleep apnea. Moreover, it underscores the therapeutic potential of targeting the SIRT1/EGR1/GLS2 pathway to mitigate hypoxic lung injury in clinical settings.

Frequently Asked Questions

How does chronic intermittent hypoxia induce ferroptosis in lung tissue?

Chronic intermittent hypoxia generates excessive reactive oxygen species while significantly depleting intracellular glutathione levels within pulmonary tissue. This metabolic disruption severely impairs glutathione peroxidase 4 activity, leading to toxic lipid peroxidation and structural mitochondrial collapse. Consequently, bronchial epithelial cells undergo iron-dependent ferroptotic cell death, which directly drives widespread alveolar structural damage and persistent lung injury in obstructive sleep apnea models.

What role does the SIRT1/EGR1/GLS2 axis play in preventing cellular damage?

The SIRT1/EGR1/GLS2 axis serves as a critical signaling pathway regulating intracellular antioxidant defenses during hypoxic stress. Activation of SIRT1 upregulates early growth response factor 1, which directly binds to and transcriptionally activates the glutaminase 2 promoter. Elevated glutaminase 2 expression significantly enhances glutathione biosynthesis, empowering glutathione peroxidase 4 to eliminate lethal lipid hydroperoxides and successfully preserve cellular integrity during severe intermittent hypoxia exposure.

Can resveratrol be considered a primary treatment for obstructive sleep apnea?

Resveratrol is currently viewed as a promising adjunctive therapeutic candidate rather than a direct replacement for primary treatments like continuous positive airway pressure. While CPAP addresses mechanical airway obstruction, resveratrol targets underlying molecular pathways by inhibiting ferroptosis and reducing oxidative lung damage. Further clinical trials are necessary to determine optimal human dosing, long-term safety profiles, and therapeutic efficacy before widespread clinical implementation in sleep medicine.

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References

1. Wei F et al. Resveratrol Alleviates Chronic Intermittent Hypoxia-Induced Lung Injury by Inhibiting Ferroptosis via SIRT1-Dependent Modulation of the EGR1/GLS2 Axis. Antioxid Redox Signal. 2026 Aug 11. doi: 10.1177/15230864261477032. PMID: 42581022.