Unravelling the molecular mechanisms underlying chronic respiratory diseases for the development of novel therapeutics via in vitro experimental models.

Chronic respiratory diseases have collectively become a major public health concern and have now taken form as one of the leading causes of mortality worldwide. Most chronic respiratory diseases primarily occur due to prolonged airway inflammation. In addition, critical environmental factors such as cigarette smoke, industrial pollutants, farm dust, and pollens may also exacerbate such diseases. Moreover, alterations in the genetic sequence of an individual, abnormalities in the chromosomes or immunosuppression resulting from bacterial, fungal, and viral infections may also play a key role in the pathogenesis of respiratory diseases. Over the years, multiple in vitro models have been employed as the basis of existing as well as emerging advancements in chronic respiratory disease research. These include cell lines, gene expression techniques, single cell RNA sequencing, cytometry, culture techniques, as well as serum/sputum biomarkers that can be used to elucidate the molecular mechanisms underlying these diseases, and to identify novel diagnostic and management options for these diseases. This review summarizes the current understanding of the pathogenesis of various chronic respiratory diseases derived through in vitro experimental models, where the knowledge obtained from these studies can greatly benefit researchers in the discovery and development of novel screening techniques and advanced therapeutic strategies that could be translated into clinical use in the future.