Chronic obstructive pulmonary disease (COPD) refers to a group of diseases that cause airflow blockage and breathing-related problems. COPD affects 16 million Americans and is the third most common cause of death in the world. A new preclinical study led by the Centenary Institute and University of Technology Sydney (UTS) has identified a small RNA molecule called microRNA-21 as a therapeutic target and its inhibition as a potential treatment for COPD.

Their findings are published in the journal Science Translational Medicine in a paper titled, “A microRNA-21–mediated SATB1/S100A9/NF-κB axis promotes chronic obstructive pulmonary disease pathogenesis.”

“COPD is the third leading cause of morbidity and death worldwide. Inhalation of cigarette smoke (CS) is the major cause in developed countries,” wrote the researchers. “Current therapies have limited efficacy in controlling disease or halting its progression. Aberrant expression of microRNAs (miRNAs) is associated with lung disease, including COPD. We performed miRNA microarray analyses of the lungs of mice with CS-induced experimental COPD.”

The researchers observed elevated levels of microRNA-21 in experimental COPD models involving mice. The use of a microRNA-21 inhibitor (antagomir-21) as a therapeutic treatment was shown to reduce inflammation and improve lung capacity and function in these models.

Phil Hansbro, PhD, the study’s senior author, professor, and director of the Centenary UTS Centre for Inflammation, said that their findings offered up a completely new understanding of COPD.

Phil Hansbro, PhD, professor and director of the Centenary UTS Centre for Inflammation [Centenary UTS Centre for Inflammation]

“MicroRNA-21 is a common molecule that is expressed in most cells in the human body and regulates many critical biological processes. Our findings demonstrate, however, that microRNA-21 levels increase when it comes to COPD,” explained Hansbro.

“We believe that the development of new drugs that inhibit microRNA-21 may offer up an entirely new therapeutic approach when it comes to COPD treatment.”

The findings may address the limited effectiveness that current therapies have in controlling COPD and help modify the decline in lung function seen over time.

“The development of effective COPD treatments has been hampered by a lack of understanding of the disease’s underlying mechanisms. Our data defines microRNA-21 as a novel therapeutic target and its inhibitors as a potential new treatment for this major, currently intractable lung disease.”