Regrowing Your Own Body Parts: Is It Possible?
Australian scientists have recently shared some exciting news in the field of stem cell therapy. For the first time, researchers have been able to reprogram adult stem cells to regenerate any type of body tissue. The technique, inspired by a salamander’s ability to regrow a lost limb, makes adult stem cells lose their tissue-specific characteristics and multiply and regenerate into several different types of cells—a process referred to as multipotency. This essentially means that adult stem cells can hypothetically repair any injured body part, from torn muscles to severed spinal cords.
While there has been much hype associated with the field of stem cell therapy, current techniques remain largely unproven with little to no objective evidence of success in tissue regeneration. Currently, adult stem cells are unable to regenerate multiple types of tissues. Embryonic stem cells (ESCs) derived from developing embryos are the only multipotent undifferentiated stem cells available. However, ESCs are mired in political controversy and ethical debate because their research requires the destruction of human embryos. Besides, ESCs cannot be directly transplanted to regenerate adult tissues and they also have a propensity for uncontrolled growth, leading to the formation of tumors.
Tissue-specific adult stem cells (for instance, lung stem cells that can regenerate lung tissue) lack versatility. John Pimanda, lead researcher at the University of New South Wales Faculty of Medicine, indicates that reprogramming human fat cells to transform them into multipotent stem cells that can regenerate any type of tissue is underway in mice. Trials in humans are expected to begin in 2017.
The transformation of adult stem cells into pluripotent stem cells (which are even more adaptable than their multipotent counterparts), has been achieved, but only with viruses necessary for resetting the cells, which is unacceptable in humans.
The new technique overcomes both issues—the tumor-forming tendency of ESCs and the necessity for viruses. Researchers obtained bone and fat cells from adult humans and treated these with platelet-derived growth factors and Azacitidine (a chemotherapeutic agent used to treat leukemias and diseases of the bone marrow). This cocktail jump-started the de-differentiation process in the extracted cells, gradually reversing their tissue-specific hardwiring over a period of a few weeks and converting them to multipotent stem cells capable of repairing any type of tissue.
Pimanda and his associate Vashe Chandrakanthan state that the process essentially switches off the memory of the adult fat and bone cells. The technique is still proven only in concept, but the scientists are furthering their research by trying to heal damaged tissue in mice by using human multipotent stem cells. It also remains to be seen how these cells will react at the site of transplantation. The upcoming initial trials in humans will focus on treating injuries and chronic back pain by attempting to repair damaged bones, muscles, and joints.
References:
http://www.sciencealert.com/new-stem-cell-treatment-using-fat-cells-could-repair-any-tissue-in-the-body
Image courtesy of: https://www.sciencedaily.com
