Review Explores Link Between COPD, Stem Cells and Reactive Oxygen Species

A study recently published in the journal Oxidative Medicine and Cellular Longevity reviewed the link between reactive oxygen species (ROS), stem cell aging and lung disorders like chronic obstructive pulmonary disease (COPD). The study is titled “Reactive Oxygen Species in Mesenchymal Stem Cell Aging: Implication to Lung Diseases” and was developed by researchers at Kangwon National University and Seoul National University in the Republic of Korea.

Human tissue-derived mesenchymal stem cells (MSCs) are a promising cell-based therapeutic approach for several diseases, including pulmonary disorders, due to their regenerative, anti-inflammatory and immunomodulatory properties. MSCs can be isolated from several tissues including the bone marrow, skin dermis, adipose tissue, hair follicle and umbilical cord blood. Their function in the body is to maintain homeostasis and control tissue repair mechanisms. After a fixed number of cell divisions, MSCs start deteriorating (aging). These residual MSCs experience a decline in their proliferative and functional abilities.

ROS are naturally occurring molecules that result from oxygen metabolism. They play an important role in cell signaling and, when present in high levels, can induce significant damage to cell structures triggering apoptosis (programmed cell death). It has been recently reported that ROS can have either a deleterious or a beneficial action depending on their concentration in MSCs. For instance, high levels of ROS can trigger an abnormal differentiation on MSCs.

MSCs-based therapies have been shown to induce a significant decrease in lung inflammation and symptoms amelioration in lung conditions such as COPD, one of the most common lung diseases and a major cause of morbidity and mortality worldwide (third leading cause of death in the United States). COPD is a progressive disease in which individuals develop serious problems in breathing with obstruction of the airways, shortness of breath (dyspnea), cough and acute exacerbations. Smoking is considered to be the leading cause of COPD and the disease can seriously impact the patient’s physical capacity, well-being and social functioning.

COPD prevalence is two to three times higher among individuals more than 60 years old. According to the authors, this increase in the elderly population is thought to be linked to the age-associated functional and structural changes in the lungs that may turn individuals more susceptible to COPD. In COPD patients, cigarette smoke exposure and aging accelerates cellular deterioration, which ultimately leads to an increase in ROS production in the lung tissues and an inflammatory state.

In conclusion, the authors suggest that MSCs-based therapies can be considered a new therapeutic approach for COPD, and emphasize that excessive levels of ROS can have a negative impact on the lung homeostasis and promote lung MSCs aging in COPD patients, ultimately impairing MSCs function and regenerative potential. The authors suggest that future studies should focus on the ROS-mediated mechanisms that regulate residual stem cells, as a better understanding of these processes may help on the design of effective stem cell based or antioxidant therapies for certain tissues, including the lungs.