Identification and characterization of mesenchymal stem cells in the human lung

Abstract

Background: Mesenchymal stem cells (MSC) have been described in many organs, but their presence, characteristics and function in human lungs (LMSC) remains elusive. Their potential pathogenic role in patients with chronic obstructive pulmonary disease (COPD) is also unclear. And, finally, recent studies in animal models have showed a protective role of bone marrow MSC transfer, but little is known about the ability of regeneration of human lung itself. Objectives: To identify, isolate and characterize LMSC in non-smokers, smokers with normal lung function and patients with COPD. Methods: We used fresh lung tissue explants obtained from individuals undergoing resectional lung surgery (mostly because of lung cancer), in combination with cell culture, flow citometry and qPCR techniques to isolated and characterized LMSC. Results: We isolated LMSC from all three groups of individuals. These LMSC: (1) express MSC cell surface markers, such as CD105, CD90 and CD73 (2) express MSC transcription factors including oct4 and Klf4 and (3) have the ability to differentiate in vitro to adipocytes and osteoblasts. Differential characteristics of LMSC across groups are currently being investigated. Conclusions: We have identified a population of lung resident mesenchymal stem cells (LMSC) with the potential to contribute to COPD pathogenesis.