The Roadmap consists of 7 parts. This is the second one. Any comments and edits are more than welcome. Please, let me know what you think.
Also, if you could suggest a way to publish it somewhere in a nice journal that would be great. Thanks!
One of the basic processes happening during tissue regeneration is transformation of epithelial cells into mesenchymal and the other way around, mesenchymal cells into epithelial. The term is epithelial-mesenchymal transition. The picture above shows the difference between these two basic cell phenotypes. Note, that there are no other ones in multicellular tissues. Epithelial cells are bound tightly to each other and to extracellular matrix. The extracellular matrix is the basal lamina, which serves as a sort of bed for epithelial cells, which form a “topping”. Mesenchymal cells are located within a 3D extracelllular matrix. They are bipolar, which means they have different cytoskeleton arrangement and distinct organelle distribution inside them. For example, mesenchymal cells have lamellipodia at their leading edge. These structures help them migrate inside the tissue.
Surgeon Anthony Atala of Wake Forest University Baptist Medical Center used lab-grown urethras to treat patients with damaged urinary tracts.
Five boys aged 10 to 14 were involved in the study and it took place at the Federico Gomez Children’s Hospital in Mexico City. Basically, Atala took each patient’s bladder cells and grew the cells on a scaffold. After about four to seven weeks, the cells grew into an ideal structure on the mesh-like tube and soon enough, the cells were ready for implantation.
At that point, the damaged tissue was removed and surgically replaced with the regenerative tissue custom-made for each patient. The urethra function in the male patients returned to normal and it only took three months. Even six years in, the tissue appeared to be working normally. Currently, treatment for damaged urethras involves skin grafts – but the failure rate of skin grafts is about 50 percent.
Researchers at the Cincinnati Children’s Hospital Medical Center have recently made functional human intestinal tissue from pluripotent stem cells. The researchers project that this will push the boundaries of research into how the intestines develop and work. It will also help with understanding the diseases that affect this organ and aid in producing intestinal tissues for transplant.
The study’s senior investigator, James Wells, Ph.D, stated that this was the first time cells in a petri dish were programmed to efficiently mimic the cell structures of human intestinal tissue. Regarding the future applications of this find, he said, “The hope is that our ability to turn stem cells into intestinal tissue will eventually be therapeutically beneficial for people with diseases such as necrotizing enterocolitis, inflammatory bowel disease and short bowel syndrome.”
Researchers at Cambridge and Edinburgh have discovered a way for stem cells in the brain to regenerate myelin, which is needed to protect nerve fibers. The studies, performed on rats, are exciting because they offer new hope that in the future, the damage done by multiple sclerosis could be repaired and physical function lost by patients could be restored.
The studies indicated that the patient’s own brain could be stimulated to regenerate myelin. Professor Charles ffrench-Constant, one of the lead researchers, was hopeful that the discoveries made could lead to the development of new drugs. “The discovery is very exciting as it could potentially pave the way to find drugs that could help repair damage caused to the important layers that protect nerve cells in the brain.”
Researchers at the State University of Buffalo, New York have come up with a way to grow adult stem cells continuously, offering a way to speed development of regenerative therapies. The research team, led by prof. Techung Lee, have engineered adult stem cells that scientists can grow continuously in culture.
One of the obstacles in studying adult stem cells has always been that they tend to die after only a few weeks. Techung Lee, said he and his students were growing frustrated by that, so he decided it was time to solve that problem once and for all. “We were annoyed by the inconvenience of harvesting bone marrow,” he said.