Screening of plasma exosomal lncRNAs to identify potential biomarkers for obstructive sleep apnea

Advances in non-coding RNA as a biomarker for obstructive sleep apnoea hypoventilation syndrome

PURPOSE

Obstructive sleep apnoea hypoventilation syndrome (OSAHS) is a common sleep disorder that affects multiple body systems, which in turn is closely associated with cognitive dysfunction, diabetes mellitus, oncological cardiovascular diseases and metabolic disorders. In recent years, non-coding RNA (ncRNA) has emerged as a new opportunity for biomarker discovery. We therefore discuss the research progress and potential role of ncRNAs in obstructive sleep apnea hypoventilation syndrome.

METHODS

This review systematically searched relevant academic literature from PubMed, Web of Science and other databases. During the retrieval process, a combination of keywords such as "OSAHS", "ncRNA", "lncRNA", "miRAN", "circRNA" was used for search.

RESULTS

Circulating ncRNA has good area under the ROC curve, sensitivity and specificity in the diagnosis of OSAHS, and has the potential to become a diagnostic marker for OSAHS, while several circulating ncRNAs or circulating ncRNAs in combination with other tests such as the Obstructive Sleep Apnoea Screening Scale have a higher value of application as a test for OSAHS. Further analyses revealed that many circulating ncRNAs were significantly differentially expressed in the serum of OSAHS patients with different very severities, a potential marker for predicting the severity of OSAHS, and that the ncRNA content of patients' serum also had a significant effect during CPAP therapy, suggesting that it may have potential for therapeutic monitoring. Meanwhile, serum ncRNAs from patients have been shown to be effective in the diagnosis of OSAHS complications such as hypertension, Alzheimer's disease, acute myocardial infarction and atherosclerosis. The expression of up- or down-regulated ncRNAs can regulate different signalling pathways, which in turn affects various OSAHS complications such as pulmonary hypertension, diabetes mellitus, and cognitive dysfunction, and is expected to become a new direction for the treatment of these complications.

CONCLUSIONS

The changes in ncRNA expression in OSAHS patients are expected to be a novel biomarker for the diagnosis and treatment of OSAHS, and can also be used as a potential biomarker for the combination of diabetes mellitus, cardiovascular disease, respiratory disease, and cognitive dysfunction in OSAHS. It is believed that the continuous progress of ncRNA-related research is expected to promote the early detection, diagnosis and treatment of OSAHS and its complications.

Epigenetic regulation of pulmonary inflammation

Pulmonary disease such as chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis and pulmonary hypertension are the leading cause of deaths. More importantly, lung diseases are on the rise and environmental factors induced epigenetic modifications are major players on this increased prevalence. It has been reported that dysregulation of genes involved in epigenetic regulation such as the histone deacetylase (HDACs) and histone acetyltransferase (HATs) play important role in lung health and pulmonary disease pathogenesis. Inflammation is an essential component of respiratory diseases. Injury and inflammation trigger release of extracellular vesicles that can act as epigenetic modifiers through transfer of epigenetic regulators such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), proteins and lipids, from one cell to another. The immune dysregulations caused by the cargo contents are important contributors of respiratory disease pathogenesis. N6 methylation of RNA is also emerging to be a critical mechanism of epigenetic alteration and upregulation of immune responses to environmental stressors. Epigenetic changes such as DNA methylation are stable and often long term and cause onset of chronic lung conditions. These epigenetic pathways are also being utilized for therapeutic intervention in several lung conditions.

The role of lncRNAs in intermittent hypoxia and sleep Apnea: A review of experimental and clinical evidence

In this narrative review, we present a comprehensive assessment on the putative roles of long non-coding RNAs (lncRNAs) in intermittent hypoxia (IH) and sleep apnea. Collectively, the evidence from cell culture, animal, and clinical research studies points to the functional involvement of lncRNAs in the pathogenesis, diagnosis, and potential treatment strategies for this highly prevalent disorder. Further research is clearly warranted to uncover the mechanistic pathways and to exploit the therapeutic potential of lncRNAs, thereby improving the management and outcomes of patients suffering from sleep apnea.

Pathophysiological mechanisms and therapeutic approaches in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is a common breathing disorder in sleep in which the airways narrow or collapse during sleep, causing obstructive sleep apnea. The prevalence of OSAS continues to rise worldwide, particularly in middle-aged and elderly individuals. The mechanism of upper airway collapse is incompletely understood but is associated with several factors, including obesity, craniofacial changes, altered muscle function in the upper airway, pharyngeal neuropathy, and fluid shifts to the neck. The main characteristics of OSAS are recurrent pauses in respiration, which lead to intermittent hypoxia (IH) and hypercapnia, accompanied by blood oxygen desaturation and arousal during sleep, which sharply increases the risk of several diseases. This paper first briefly describes the epidemiology, incidence, and pathophysiological mechanisms of OSAS. Next, the alterations in relevant signaling pathways induced by IH are systematically reviewed and discussed. For example, IH can induce gut microbiota (GM) dysbiosis, impair the intestinal barrier, and alter intestinal metabolites. These mechanisms ultimately lead to secondary oxidative stress, systemic inflammation, and sympathetic activation. We then summarize the effects of IH on disease pathogenesis, including cardiocerebrovascular disorders, neurological disorders, metabolic diseases, cancer, reproductive disorders, and COVID-19. Finally, different therapeutic strategies for OSAS caused by different causes are proposed. Multidisciplinary approaches and shared decision-making are necessary for the successful treatment of OSAS in the future, but more randomized controlled trials are needed for further evaluation to define what treatments are best for specific OSAS patients.