The fat cells in our body consist of a variety of cells, that has the potential to become bone, cartilage, or more fat if properly prompted. So, in theory the adipose tissue is a reservoir in the body that can be used in various regenerative therapies like bone healing, etc. The crucial thing here is to be able to get enough of those cells and compel them to produce bone.
In this new study by scientists at the Brown University demonstrated a new method via which a variety of potential bone-producing cells could be extracted from human fat. The study was published in the journal Stem Cell Research & Therapy. They developed a fluorescent tag that has the ability to find and identify cells that expresses a gene called ALPL. The expression of this gene is an indicator of the bone making capability of the cell.
RNA is produced when this gene is expressed. If the tag finds RNA, it latches on and glows. Once that happens, a machine that detects the fluorescent light separates the ALPL expressing cells. In the study that was published, the scientists have reported that their method have yield as many as twice of the potential bone-makers than the previous method. That method which was thought to be the best method known sorted the cells based on the surface protein. The method developed in this study found potential bone makers as much as 9% while the previous method yield was just 4%.
In the next three weeks, subsequent cultivation of the similar-sized population of adipose tissues was carried out. It was observed that the ALPL expressing cells produced on average more than twice as much as the bone matrix and four times more bone matrix than cells that don’t express ALPL. It was also seen that ALPL-expressing cells were also better at making cartilage or fat.
There are a couple of other research groups who have sorted stem cells based on gene expression. However, they did not do it so specifically with the aim to enrich cell population for a specific tissue. Brown University has also filed an application for obtaining a patent on the method of gene expression tagging for producing a tissue
Hetal Marble, lead author and Brown graduate student said that the approach of sorting cells based on gene expression rather than surface protein is a paradigm shift' in the following sense Gene expression gives a way of targeting any cell based on if it can produce another tissue. On the other hand targeting surface proteins is limiting as researchers have to harvest cells that fit a presumed definition of being a stem cell. The new approach, she said, is more practical for the purpose.
The approach that has been discovered in this study allows the researchers to isolate all the cells that are capable of doing what they want. It doesn't matter if they fit the archetype of what a stem cell is or not. The paradigm shift that is being talked about is about isolating populations that are able to achieve an end result without fitting into strictly defined cells.
One drawback of the experiment is that there is a four day delay; it takes that long for the maximum number of cells to express ALPL when cells are chemically primed to do so. To avoid this, the team has thought that they will like to target a gene expressed much earlier in the differentiation process to see if they can avoid a priming period. If they can apply the method based on a gene that’s expressible within a matter of hours it could do wonders for those who need bone healing and other such treatments.