Inducible pluripotent stem cells and pulmonary arterial hypertension: the future is now!
The pulmonary circulation is responsible for directing venous (low-oxygen) blood to the gas exchange regions of the lung, where oxygen uptake takes place before arterial (oxygen-rich) blood leaves the heart via the systemic circulation. Compared to the systemic circulation, the pulmonary circulation is a low-pressure/low resistance system that maximizes the amount of venous blood entering the lungs through the pumping action of the right ventricle. However, disorders associated with abnormal increase in pressure and/or resistance can adversely affect the capacity of the right ventricle to pump blood into the lungs and reduce the oxygen content in arterial blood. This is the case with pulmonary arterial hypertension (PAH), a rare but life-threatening disorder associated with abnormally increased pulmonary pressures and right heart failure (1). Despite the availability of 14 FDA approved therapies, none are capable of curing PAH, likely due to their inability to prevent progression and/or reverse vascular pathology. Therefore, there is an unmet need to understand the pathological mechanism involved in pulmonary vascular remodeling and use this knowledge to test novel approaches to treat the disease.