MicroRNAs, also called miRNAs or miR, play an important role in cell communication and affect gene activity in various ways. The effect of miRNAs is not restricted to the individual cell: They can also reach other cells when packaged into extracellular vesicles.
It has been known for about 20 years that microRNAs (miRNAs, miR) play an important role in cellular communication. They can affect gene activity in various ways. The effect of miRNAs is not restricted to the cell in which they are produced. Packaged into extracellular vesicles (small transport vehicles), miRNAs can also reach other cells. An international team of researchers led by DZL scientists from Research Center Borstel investigated how the development of asthma affects the released miRNAs.
The researchers cultured human bronchial epithelial cells and created a situation comparable with asthma by administering interleukin 13. It became visible that the miRNA profile of the bronchial epithelial cells changed significantly. In particular, the occurrence of the three miRNAs miR‐92b, miR‐34a, and miR‐210 was reduced. All three have a regulative role in dendritic cell maturation and TH2 polarization. These immunological processes are also involved in the manifestation of asthma. To reproduce the tests in a more natural situation, the researchers performed nasal lavage in children suffering from either mild or severe asthma. A control group with healthy subjects was also included. These tests confirmed the examinations in cell culture. Again, the occurrence of the three miRNAs was reduced in the nasal lavage fluid. The researchers also found a correlation with lung function parameters: The lower the miRNA levels in the lavage fluid, the worse the children’s lung function.
Comparability of the results of bronchial epithelial cells and nasal lavage fluid is of great interest, since experimental access to the nose is easier than to the lungs, especially in children. The results obtained show the first relations between the microRNA spectrum and the development of asthma. Further studies are required to investigate the cell types on which miR‐92b, miR‐34a, and miR‐210 exactly act and the immunological processes they trigger.
Bartel et al.: Human airway epizhelial extracellular vesicle miRNA signature is altered upon asthma development. In: Allergy 2019. DOI: 10.1111/all.14008
