Respiratory diseases such asbronchitis, emphysema and asthma are extremely prevalent, with morethan 35 million sufferers in the US alone. Now, a team from theWeizmann Institute of Science has worked to create a new treatmentfor repairing damaged lung tissue, using the procedure for bonemarrow stem cell transplantation as a template.
Key to the research is the similaritybetween stem cells in the lung and those in bone marrow. In bothcases, the cells are located in specialized, provision-filledcompartments, rather than being distributed throughout the tissue.The team began work on the assumption that existing knowledge oftransplanting bone marrow stems cells might be relevant when workingwith the lungs.
In the case of bone marrow, twoprinciples are key. First is that the specialized stem cell compartment must be clear before the transplant is carried out, and second is that the cells have an innate ability to find their way to said compartment.
To see if the treatment was effective when working with damaged lungs, the researchers first obtained embryonic stemcells in their 20th to 22nd week ofdevelopment. Harvesting cells at this young age is deemed optimum, asthey've not yet completed the process of differentiation, and aremore effective at regenerating damaged tissue than older stem cells.Working with mice suffering with damaged lungs, the team then cleanedout the specialized compartments, and introduced theembryonic stem cells to the tissue.
As hoped, the cells exhibited similarbehavior seen in bone marrow stem cell treatment, finding theirway through the bloodstream and into the compartments. After some sixweeks, the cells had formed into normal lung tissue, significantlyhealing the damaged tissue and notably improving the rodents'breathing.
In light of the successful tests, theteam will continue its research, and will work to pinpoint the ideal dosage of drug required toensure that the host doesn't reject the transplanted stem cells. Inthe long run, the goal is to cultivate a bank of lung tissue that canbe used as a resource for embryonic stem cells, making it easier tocarry out the treatment in the real world.
Source: Weizmann Institute of Science