Progresses in epigenetic studies of asthma from the perspective of high-throughput analysis technologies: a narrative review

Background and Objective: Asthma is the most common chronic respiratory disease in the world with an estimated heritability between 50% and 60%, and recent studies have shown that epigenetic mechanisms play an important role in its development. Many cutting-edge epigenetic research techniques have been applied to the study of the pathogenesis of asthma, which has promoted the development of asthma etiology and brought new possibilities for treatment. We summarized recent advances in epigenetic research of the pathogenesis of asthma, especially from the perspective of high- throughput analysis techniques, to find potential epigenetic biomarkers and possible molecular targets for the future intervention and treatment of the disease. Methods: We reviewed and summarized recent progress in epigenomic studies of asthma on a "pretranscriptional level", including DNA methylation, histone modification, and chromatin remodeling, and on a "post-transcriptional level" with a focus on non-coding RNA, from the perspective of high-throughput analysis technologies. Key Content and Findings: We have summarized the progress of different kinds of recent epigenetic studies in asthma, including DNA methylation studies [candidate genes methylation studies and epigenomewide association study (EWAS)], histone modification studies (histone acetylation/deacetylation studies and histone methylation studies), non-coding RNA studies [microRNAs (miRNAs), long non- coding RNAs (lncRNAs) and circular RNAs (circRNAs)], to help the readers to gain a comprehensive insight into the epigenetic research fields for asthma. The application of high-throughput analysis techniques in asthma research, including EWAS (DNA methylation chips), chromatin immunoprecipitation sequencing (CHIP-seq), microRNA sequencing, whole transcriptome sequencing, co-expression network and competing endogenous RNA (ceRNA) analyses, were introduced accompany with the main findings. And the potential epigenetic biomarkers and possible molecular targets identified via high-throughput analyses were also discussed. Conclusions: Epigenetic research has become a hotspot in research on the pathogenesis of asthma. The combination of high-throughput epigenetic analysis technologies and traditional biological function and clinical studies will bring new breakthrough in the pathogenesis study of asthma, which will improve the genetic interpretation of the disease and bring more possibilities for the development of precision medicine to treat it.