P66Shc is increased in peripheral blood mononuclear cells of the patients with obstructive sleep apnea

Objective: Obstructive sleep apnea (OSA) is characterized by nocturnal intermittent hypoxemia and linked to oxidative stress. Evidence demonstrated that p66Shc plays a key role in regulating oxidative stress. This study aimed to investigate the expression of p66Shc in peripheral blood mononuclear cells (PBMCs) of patients with OSA and the association with polysomnographic parameters. Methods: Fifty-four OSA subjects and 19 no OSA controls were enrolled in this study. All the subjects underwent standard polysomnography. P66Shc mRNA and protein levels in the PBMCs were detected by quantitative real-time polymerase chain reaction and western blotting. Plasma 3-nitrotyrosine (3-NT), oxidized low density lipoprotein (oxLDL), and advanced oxidation protein products (AOPP) were measured by ELISA method. Results: P66Shc mRNA and protein levels in PBMCs were significantly higher in OSA patients than in controls. P66Shc mRNA was positively correlated with plasma 3-NT, oxLDL, AOPP, hypopnea index (AHI), oxygen desaturation index (ODI), percentage of total sleep time with oxygen saturation (SaO₂) below 90% (CT90), epworth sleepiness scale (ESS) and lymphocytes; negatively correlated with lowest SaO₂ (LSaO₂) and mean SaO₂ (MSaO₂). Further multivariate linear regression analysis showed that p66Shc mRNA levels were independently associated with AHI, MSaO₂ and CT90. Conclusions: Oxidative stress regulator p66Shc may play a role in the pathophysiology of OSA and might serve as a potential biomarker for this disease.