In my search through the medical research to find genetic or biomedical solutions towards height increase, there was one idea that I thought of which I felt needed to be considered. Looking through the internet space, there were very few resources available which also considered the idea, mainly because the method is VERY radical.
The idea is limb regeneration. Currently, there are research being done by scientists who are looking for a way to stimulate human limb regeneration. If we can through some form of genetic engineering turn on our genes to regrow our limbs, we can theoretically remove our limbs and let them regrow back and apply tensile force on the replacement limb which regrows back at the old one’s place there by allowing us to add the inches we need. Of course, the venture and idea is easier said then done.
The first question to ask is how much progress has already been made in even the idea of limb regeneration in general? So far, there has been progress in this venture.
There were threes main groups who did research on two types of animals, the zebrafish , the newt, and the salamander. I wanted to talk about the research with the zebrafish, which has been known to have the ability to regrow their fins and even heart muscle after injury. The resource used was the one from the Daily Mail UK
A group of researchers from the University of Konstanz in southern Germany said that they found out the reason why the zerbrafish can regrow lost parts so well. Gerrit Begemann is the head of the research group and states that retinoic acid is the critical compound used to restore the limbs. Taken from the written article..
Before the zebrafish’s fins regenerate, the wound is closed with multiple layers of tissue. The cells beneath the stump then lose their identity and form what is called blastema.
Researchers found that the fish uses a special genetic trick that allows the acid to control the formation of blastema, which means the animal is able to produce a store of cells that can rebuild the fin.
Retinoic acid is produced by animals, including humans, from vitamin A and can activate the necessary genes for regeneration.
It has been shown that pregnant women who do not take enough vitamin A in their diet can have underdeveloped foetuses (resource is Daily Mail UK)
For the second project, the animal experimented on was the salamander and the findings of this experiment had even more implications. The article on the scientific study was written for the journal Nature. Let me try to explain the findings as well as I can.
What is well established is that the way slanders can regenerate their limbs by formed a glob of cells called the blastema on the tip of the limb stump and new cells are believed to accumulate on the blastema and then somehow de-defferentiate themselves so they revert back into pluripotent cells. embryonic stem cells are themselves pluripotent, which means that the cells have the ability to transform themselves into whatever type of cells they are instructed to become.
What the study showed was that the cells that accumulate on the blastema don’t revert completely back to such a embryonic young self but only partially. This is sort of good news for scientists who are trying to find a path to induce tissue and/or limb regeneration because it means they don’t have to push the limits of nature and genetics so far that they have to get cells to completely revert back to their pluripotent cells, but only partially.
Taken from the resource for WIRED
Having first added a gene that makes a fluorescent protein into the genomes of axolotl salamanders, Tanaka’s team removed from their eggs the cells that would eventually become legs. They fused the cells into new eggs; when these matured into adult salamanders, cells in their legs glowed under a microscope.
After the researchers amputated their salamanders’ legs, the legs regrew. Cells in the new legs also contained the fluorescent protein and glowed under a microscope, so the scientists could watch blastemas form and legs regrow in cell-by-cell detail.
Contrary to expectation, skin cells that joined the blastema later divided into skin cells. Muscle became muscle. Cartilage became cartilage. Only cells from just beneath the skin could become more than one cell type.
“People didn’t know if the salamanders were special because they forced adult tissues to become pluripotent, and whether we should look for factors that did that — or if, as we find now, we actually shouldn’t try to force cells back to a pluripotent state,” said Tanaka.
Whether this striking absence of pluripotency is universal is still unknown. The experiment needs to be replicated independently in other salamander species.
“This represents a parallel approach for how to make cells in regenerative medicine,” said Melton at the time. “If you’ve got extra cells of one type and need another, why go all the way back to a stem cell?”
Tanaka next hopes to decipher the genetic instructions governing blastema formation. But however the pluripotency–versus–partial-reprogramming debate turns out, her team’s development of a genetically modified axolotl as a model organism for regenerative research is significant.
“”What do these amphibians have that we lack?
Some have attributed the regenerative potential, in part, to stem cells that remain in adult tissue — but there don’t seem to be enough of them in newts to get the job done. Instead, most biologists believe that, in vertebrates endowed with regenerative ability, muscle cells surrounding injured tissue temporarily regress to a more primitive state, re-entering the cell cycle and then proliferating to produce more muscle cells.
Past studies have identified a protein called retinoblastoma protein (Rb) as a key factor in getting muscle cells to differentiate, or specialize. Suppression of the Rb gene in newt muscle cells sends the cells back into the cell cycle, but this doesn’t work in mammalian muscle cells.
Blau and her colleagues proposed that, in mammals, an additional mechanism may have evolved atop the Rb pathway to confer tumour suppression. Unlocking regeneration in mammalian tissues may involve interfering with that pathway too.
The researchers homed in on a tumour-suppressor gene called Arfthat is present in mammals but not in regenerating vertebrates. Using a gene-silencing technique called RNA interference to temporarily knock down both Arf and Rb in cultured mouse muscle cells, they found that the treated cells re-entered the cell cycle and began proliferating.
When the genes’ activities were restored, the cells returned to their differentiated state. Newly generated muscle cells transplanted into living mice were able to integrate into the animals’ muscle tissue. “”
“”Ken Poss, a cell biologist at Duke University Medical Center in Durham, North Carolina, cautions that several unknowns remain in determining whether the technique will aid regeneration.
First, Poss notes, it’s still unclear whether de-differentiation is the main trick that animals such as newts rely on for tissue regeneration. Researchers aren’t sure how much of the effect can be attributed to muscle stem cells called satellite cells. Furthermore, he says, regenerating large chunks of tissue may involve recreating the connective-tissue scaffolding on which muscle cells grow — a step that’s not part of this technique. ‘”
Me: Here is what I will conclude from looking through these 4 articles. the application of human tissue growth and regrowth is a big biotech subject that will come out in the next few decades. I wouldn’t be surprised that when I reach the age of 60 or 70 and I develop hip or knee problems that researchers would have figure out a way to allow my own body to regrow it’s own lost parts back. As for the use for the technology for human limb regeneration to be used for height increase, we can probably make the process of healing and bone regrowth go a lot faster if we get the technology go tissue regeneration figured out. We can theoretically regrow longer limbs if we wanted to grow our bodies taller.
To learn more about human limb regeneration, please refer to the Wikipedia article on Human Limb Regeneration click HERE.