In Tongji University in China, researchers have developed an innovative technology for regenerating human lungs. In a successful clinical trial, autologous lung stem cell transplantation was carried out to regenerate damaged lungs of patients.
This study was reported in open access journal Protein & Cell (This journal was published by Springer Nature.). Professor Zuo and his colleagues successfully published this paper in 2015. They identified p63+/Krt5+ adult stem cells in mouse lungs that could regenerate bronchioles, alveoli, and other pulmonary structures.
Following this successful breakthrough, these researchers from Tongji University are now working in conjunction with Kiangnan Stem Cell Institute to apply the same discovery to human cells, rather than mice.
Human lungs are completely different from that of mice, both in terms of anatomy and developmental processes. Therefore, chronic pulmonary disorders can be solved by directly investigating human lungs.
An SOX9+ marker was used to label the category of basal cells, which could be cloned into lung stem cells in human beings. Professor Ren Tao is a renowned physician who worked in Shanghai East Hospital.
To produce lung stem cells from tiny samples of basal cells, lung bronchoscopy was performed by a team of researchers headed by Professor Ren Tao.
Lung stem cells were produced from about 0.2% of cells from each brush. A scaled expansion was conducted in a well maintained fashion to ensure genetic stability and molecular phenotypes of these cells.
To determine the capacity of lung stem cells and to regenerate lung tissue in vivo, GFP-labeled human lung stem cells were transplanted into damaged lungs of immunodeficient mice.
Three weeks after transplantation, a “human-mouse chimeric organ” was formed by integrating human lung stem cells in a large area of mice lungs.
By performing histological analysis, the transplanted stem cells were regenerated into bronchial and alveolar structures in lungs of mice. Around the regenerated structures of human alveoli, host capillaries were observed to be rising.
In other words, functional respiratory units were generated and they were detected by gold nanoparticle tracking technique. After performing stem cell transplantation successfully, new human alveoli were formed in place of fibrotic area in injured lungs. Lung function in mice was significantly restored by performing arterial blood gas analysis.
The first clinical trial was performed successfully by a team of researchers from the following organizations: Southwest Hospital of China Army University and Regend Therapeutics.
An autologous transplantation of lung stem cells was carried out for the treatment of bronchiectasis. Bronchiectasis is defined as a permanent injury that is caused to the bronchial structure of lungs. Two patients were included in this study in March 2016 following strict supervision by ethical committees.
The generated lung stem cells were transplanted into patients’ lung by performing bronchoscopy. These patients were then monitored for one year continuously. Multiple respiratory symptoms, such as coughing and dyspnea, were mitigated in these patients, one year after transplantation.
The dilated structures showed almost complete recovery as per CT images. Three months after transplantation, patients showed an improved in lung function and they showed further signs of recovery till one year.