Protein Critical for Tissue Regeneration Discovered

A flatworm well-known for its unique ability to regenerate cells is giving scientists at the University of California, more light on how cancer could be treated and how regenerative medicine could better target diseases.

It has been shown that signaling by a protein called Target of Rapamycin (TOR) found in humans and most other mammals, is vital for Planaria’s unique tissue regeneration. Disabling the protein stops the flatworm’s regeneration, showing that disabling it in abnormal cells could possibly prevent the growth of a cancer.

Researchers have identified that the TOR protein plays a role in cancer, aging and degenerative diseases, but they haven’t found the answer to how it works.

Methods—

One lab is approaching this question using tiny flatworms known as Planaria. The planarian is now among the species that could be crucial in understanding the role of stem cells due to its ability to repair itself, and its secrets could help combat cancer and degenerative diseases.

For this study, the researchers disabled the TOR protein in Planaria and then amputated parts of the flatworm. Under typical circumstances, the organism would be able to repair itself.

Results—

Researchers discovered the Planaria’s stem cells recognized they needed to regenerate tissue but were unable to do so in the correct place and instead formed tissues in abnormal places. This kind of regeneration hasn’t been observed before. Furthermore, the Planaria with the disabled protein were unable to grow, even if nutrients were available.

Conclusion—

In addition to stopping cancer, understanding TOR and its role in regulation could direct to the development of medicines to encourage tissue regeneration and to fight degenerative diseases, such as Alzheimer’s.

Strengths and Weaknesses of this study—

Understanding the role of the TOR protein could lead to the development of medicines against cancer and other regenerative diseases, however, researchers have not figured out how this protein works which is a weakness of this study.

New method for engineering human tissue regeneration

If proven successful, pending clinical trials in Yale University represent a significant scientific leap toward human tissue regeneration and engineering. In a recent research report, Yale scientists provide evidence to support a huge paradigm shift in the area of human tissue regeneration from the idea that cells added to a graft before implantation are the building blocks of tissue, to a novel belief that engineered tissue constructs can actually induce or increase the body’s own reparative mechanisms, including complex tissue regeneration.

• Methods

Breuer and his colleagues in this study conducted a three-part study, starting with two groups of mice. The first group expressed a gene that made all of its cells fluorescent green and the second group was normal. Next, Researchers extracted bone marrow cells from the “green” mice, added them to formerly designed scaffolds, and implanted the grafts into the normal mice.

• Result

The seeded bone marrow cells enhanced the performance of the graft; however, a rapid loss of green cells was observed and the cells that developed in the new vessel wall were not green which suggests that the seeded cells promoted vessel development, but did not turn into vessel wall cells themselves. Thus, these findings directed to the second part of the study, which tested whether cells produced in the host’s bone marrow might be a possible source for new cells.

Second study

Researchers replaced the bone marrow cells of a female mouse with those of a male mouse before implanting the graft into female mice. They found that the cells forming the new vessel were female, meaning they did not come from the male bone marrow cells.

Third study

Researchers implanted a segment of male vessel attached to the scaffold into a female host. In result, researchers found that the side of the graft next to the male segment developed with male vessel wall cells while the side of the graft attached to the female host’s vessel formed from female cells, meaning that the cells in the new vessel must have migrated from the adjacent normal vessel.

Advancement in Tissue Engineering Promotes Oral Wound Healing

Oral tissue engineering for transplantation to help wound healing in the oral cavity reconstruction has taken a considerable step forward. According to the study’s lead author, Dr. Susan Gibbs of the VU University Medical Centre in Amsterdam, skin substitutes have been far more advanced than oral gingiva substitutes. Until now, no oral tissue-engineered products have been available for clinical applications. This study was aimed at constructing full thickness oral substitutes while maintaining the needed characteristics for successful oral transplantation. Researchers used small amounts of patient oral tissue acquired from biopsies, the cultured and expanded the tissues in vitro over a three-week period.

Results of this study showed with a few number of patients showed that the gingiva substitute was promising and supported the need to carry out a larger patient study in the future.