Repair of Lung Cell Lining
Here is something unusual. Let us share with you a video footage on behavior of cells in culture that PhD student Ms. Sushreesangita P. Behera under Dr. Rajiv K. Saxena (Faculty of Life Sciences and Biotechnology South Asian University, New Delhi) recorded during her experiments. The cells that line the lung (lung epithelial cells) often get damaged due to pollutants and pathogens that enter through the air we breathe.
How is that damage repaired? When lung epithelial cells are cultured in laboratory, they form a layer like the lining of lung. If we make a scratch in that layer, that “wound” is repaired by cells from the surrounding areas by dividing and moving into the wound area. Watch the video on how this happens.
Feel free to read the just published research paper on this topic and you may enjoy watching this process under live imaging microscope. School children may also enjoy watching live cells dividing and migrating in laboratory cultures. The clip is presented by compressing of time scale. The actual duration of the clip would be 24 hours. The video is presented below:
In fact the research paper says that the exposure to airborne nanoparticles can inhibit this repair process.
Link to Research Paper:
The development of the lung, or pulmonary system, is an evolutionary adaptation to life on land. Lungs are essential in most adults for an existence. Their complex structure makes them an interesting yet difficult organ to study from a regeneration medicine perspective. To add to it, lung disease is one of the leading causes of death in the world, surpassed only by cardiovascular disease and cancer.
The lungs are the primary organs for respiration, the process by which we breathe out carbon dioxide and take in oxygen. The epithelial cells lining the respiratory tract have been thought to have a lower rate of cellular turnover in adult lung compared to high turnover organs such as the intestine.
After lung injury by many harmful pathogens, inflammation occurs to protect the host. Although excessive inflammation damages lung tissue, the inflammatory cells are essential for regeneration because they remove those harmful pathogens.
During the last 10 years, there has been a tremendous increase in the use of nanoparticles and nanomaterials in several areas of human life, chemical industry, food technology, cosmetics and biomedicine, among others. This rise in use of these nanoparticles is the consequence of developments in nanotechnology.
Particle sizes up to 100 nanometers determine changes in the physical and chemical properties of materials compared to those observed at larger scales; for example, chemical reactivity, electrical conductivity, melting point and magnetism are all affected by size. This is primarily due to the increase in surface area of nanomaterials compared with larger-scale particles of similar masses, enabling increased contact with the surrounding materials and therefore changes in their reactivity. As a result, the effects of human exposure to nanoparticles have attracted interest in the last few years from a safety/health point of view.
Let us look again at this video where Live cell imaging has been used to study the cell migration process of lung epithelial cells. It is really interesting to watch how cells collectively migrate to fill up once the gap is made.
Human exposure to nanomaterials and nanoparticles is increasing rapidly, but their effects on human health are yet largely unknown. However, the challenge for the future will be to determine the possible functional consequences and the potential effects on health.