Roles of Pyruvate Kinase M2 in Pulmonary Diseases: What Do We Know So Far?

Pyruvate kinase M2 (PKM2) is a critical enzyme regulating cell metabolism and growth under different physiological conditions. In its metabolic role, PKM2 catalyzes the final and also a rate-limiting reaction in the glycolytic pathway, converting phosphoenolpyruvate (PEP) to pyruvate while phosphorylating adenosine diphosphate (ADP) to pyruvate and adenosine-triphosphate (ATP). Also, PKM2 has been reported to function as a protein kinase that regulates gene transcription and expression involved in cellular growth and survival. Current studies have focused on the glycolytic and non‑glycolytic functions of PKM2 in various tissues and organs. In this review, we summarize the in-depth role of PKM2 in the pathogenesis in pulmonary diseases including chronic obstructive pulmonary disease (COPD), asthma, pulmonary arterial hypertension (PAH), acute lung injury (ALI), pulmonary fibrosis, infectious lung disease and lung cancer. We also discuss its potential applications in disease diagnosis and therapies.