Written by Caitlin McShea
Scientists have made a breakthrough advance in reprogramming cells in mice. This stride brings medical technology one step closer to the development of replacement tissues and organs in humans.
Medical researchers at Harvard University have successfully transformed ordinary pancreatic cells into insulin-producing cells in white, diabetic mice. Doug Melton and his colleagues, responsible for the study, are pleased by these results.
Usually, non-insulin producing pancreatic cells (referred to herein as exocrine cells) make up over 90% of the pancreatic cell mass, therefore Melton’s success at transforming common exocrine cells into necessary, though much rarer, insulin-producing pancreatic cells (herein referred to as beta cells) may expedite the discovery of a plausible cure for diabetes.
In type I diabetes patients, the beta cells are the first to die, creating a sufficient lack of insulin production in the body. Since insulin works to mediate the amount of sugar present in the bloodstream at any given time, those without adequate insulin levels experience higher blood sugar levels.
Up until now, the most common mode of treatment has involved painful blood testing and daily insulin shots for type I individuals, or insulin medication for type II diabetes patients. Melton hopes that the presence of these transformed beta cells in his affected mice will work to cure their diabetes completely.
Melton and his team injected the mice with a poison, which targeted and killed the insulin-producing beta cells, causing diabetes in his experimental sample. Then, Melton proceeded to inject the pancreas of each mouse with a viral cocktail, which sought out the exocrine cells present. These viruses inserted three different genes which controlled the activity of other genes, changing their enzymatic processes altogether. After only five days, 20 percent of the virally infected cells began producing insulin. Their results were published in Nature, an online journal on Wednesday, August 27th.
As of now, this early after the beta cell transformation, it should be noted that Melton’s mice still display higher than average blood sugar levels.
John Gearhart, Professor at the University of Pennsylvania and the man who led the first American team to isolate and identify human embryonic stem cells, called Melton’s work a major leap in cell reprogramming.
The altered cells were not removed from the animals in any way. The transformation occurred within the organ, no Petri dish needed. Melton and his colleagues were able to transform neighboring exocrine cells already present within the mice into beta cells without the use of embryonic stem cells.
The development of these new cells without the use of embryonic stems cells relieves a lot of concern regarding the generation of replacement cells, tissues, and organs. It might seem promising, as several people in the American public are worried about the use of embryonic stem cells in medical research to find a potential cure for diabetes. However, it may also lead to reproductive cloning, a practice that some argue devalue the worth of human beings. Likewise, storms of debates still circulate around the use and possible destruction of what some groups believe to be potential lives.
Doug Melton began his diabetic research in 1993, after his son was diagnosed with type I diabetes. His obsession with the pursuit of a cure for diabetes has only grown since then, and his work has finally paid off. Several medical peers of Melton’s view this reprogramming approach as the first step towards a cure.
“I wake up every day thinking about how to make beta cells,” Melton jokes in an interview last Wednesday published online at CNN news.
When perfected, Melton hopes to help create drugs that would replace the viral injections necessary to start the transformation process.
Mark Kay, a researcher for Stanford University, expressed in an interview with the White Coat Notes, a medical publication in Boston, that this procedure “brings more excitement to the idea of using reprogramming as a way of treating diabetes,” and other diseases. Currently, he is testing Melton’s approach on liver cells.
Melton cautions other researchers from applying his reprogramming approach to other organs so soon, since pancreatic exocrine cells are so closely related to pancreatic beta cells. He can’t be certain that other, more distantly related cells will respond in the same way.
Though Melton warns the public that this reprogramming approach is not yet ready for humans, he does express his excitement for the many potential applications this procedure may have. With the reprogramming of pancreatic cells comes the possibility for the regeneration of neurological cells destroyed during a stroke or aneurism, muscular cells affected by palsy or dystrophy, heart tissue in heart attack victims, or nerve cells in patients with Lou Gehrig’s disease.
For those of us on campus, these advances may prove to be life changing ones. Personally, I’ll announce how excited I am by the prospect of a diabetes cure, since I watched my parents prick their fingers and inject their stomachs three or four times daily just to keep their blood sugar levels in check. I know that some friends of mine have grandparents in the early stages of Alzheimer’s, and I’m sure they would more than celebrate a cure for the tragic disease. Whatever the personal circumstances, students and faculty members alike on campus may already know someone suffering with these afflictions, but you can now rest assured that Doug Melton’s research has brought us all one step closer to relief.