Tag Archives: stem cell research

Pigmented epithelial cells were grown from embryonic stem cells prior to injection.

Stem cells treatment dramatically improves vision of the blind

Pigmented epithelial cells were grown from embryonic stem cells prior to injection.

Pigmented epithelial cells were grown from embryonic stem cells prior to injection.

Detailed in a recently published study, a team of ophthalmologists have successfully managed to improve the vision of both of their trial patients, which were declared legally blind due to macular degeneration, by inserting human embryonic stem cells into one eye of each person. Significant improvements were recognized shortly after the procedure, and continued to progress positively in the months that came after, as well. The other eyes that were left untreated remained in the same poor condition as prior to the operation .

Macular degeneration is the leading cause of vision loss among the elderly, while Stargart’s muscular dystrophy, or Stargart’s disease, is a common cause of vision loss among children and young people. Drugs, laser treatment of the retina and so forth only help in slowing down the process, but the end scope of these diseases cannot be derailed, and hence are considered incurable.

Stem cell treatment has been considered an option before, however the procedure conducted by the team of scientists, lead by Steven Schwartz, an opthalmologist and chief of the retina division at UCLA’s Jules Stein Eye Institute, is the first one of its kind.

“This is a big step forward for regenerative medicine, said Dr. Steven Schwartz at UCLA’s Jules Stein Eye Institute. “It’s nowhere near a treatment for vision loss, but it’s a signal that embryonic stem-cell based strategies may work.

The operation involved injecting stem cells into one of each patient’s eye, a 78 year old woman suffering from macular degeneration and another woman, aged 51, who suffered from Stargardt’s macular dystrophy, both declared legally blind, with hopes that the cells required for proper vision will regenerate. The stem cells were treated before being injected into the patients’ eyes, as they were induced to grow into retinal pigment epithelial cells. The loss of these cells located in the pigmented layer of the retina is the leading cause of macular dystrophy.

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The results post the half hour surgery, in which 50,000 stem cells were injected, were remarkable – just a few weeks after the patients went from barely recognizing a hand to counting fingers, reading their own handwriting, pouring a glass of water without spilling it all over the floor and so on. In short, they were given the chance to live a normal life once more. Their vision continued to improve months after the surgery. The patients were also given immunosuppressants to prevent their bodies from rejecting the foreign tissue.

Other scientists have recently commented upon the research, admitting the results are indeed remarkable, while warning at the same time that the trial was conducted only on two persons,  and the improvements can still be considered short-term. Extensive studying on a broader range of patients and over longer time is required to accurately measure the effectiveness of stem cell treatment for this kind of operation.

According to Dr. Robert Lanza, chief scientific officer at Advanced Cell Technology and a co-author of the study, the embryo was destroyed after the stem cells were derived, but in the future, doctors will be able to derive stem cells from an embryo without destroying it.

The research was published in the journal The Lancet.

source: BBC via singularity hub

The rhesus monkey twins, Roku and Hex ("six" in Japanesse and Greek respectively, since they were made from six distinct genetic entities), in sound health posing for the researchers. (c) OHSU

First chimera monkeys presented by scientists

The rhesus monkey twins, Roku and Hex ("six" in Japanesse and Greek respectively, since they were made from six distinct genetic entities), in sound health posing for the researchers. (c) OHSU

The rhesus monkey twins, Roku and Hex (“six” in Japanesse and Greek respectively, since they were made from six distinct genetic entities), in sound health posing for the researchers. (c) OHSU

In Greek mythology, the chimera is a fire breathing beast composed of several animal parts (lion body, snake-head tail, a goat head hanging from its back and so on), which has spurred the imagination of man for thousands of years. Though it is fairly clear that such an abomination never existed, apart from the infinite recesses of human imagination, scientist at the Oregon National Primate Research Centre have successfully bred, not one, but three chimera monkeys – each of them made up of tissue that came from up to six distinct genetic entities.

Of course, the scientists worked only with a single species, so that means no monkeys with rhino horns or giraffe ears. The three animals, two twins and a singleton, were bred after several different rhesus monkey embryos were stuck together in their early stage of development. These were later implanted in five female rhesus monkeys, all of which became pregnant. Thus, the chimera monkeys had tissue made up of cells that came from each of the contributing embryo.

“The cells never fuse, but they stay together and work together to form tissues and organs,” said Shoukhrat Mitalipov, who led the research. “The possibilities for science are enormous.”

This isn’t the first time a chimeric animal has been bred, far from it. The first successful attempts of this kind were made in the 1960s when one by one scientists managed to give life in the lab to chimeric rats, sheep, rabbits or cattle.  In time, this kind of research proved to be invaluable for scientists’ ongoing stem cell research efforts. Understanding how during embryonic development one particular cell develops into a particular tissue in the organism is crucial.

“If we want to move stem cell therapies from the lab to clinics and from the mouse to humans, we need to understand what these primate cells can and can’t do. We need to study them in humans, including human embryos,” said Mitalipov.

 

Human ear grown in a lab from stem cells.

Lab grown stem cells may mutate in time

Human ear grown in a lab from stem cells.

Human ear grown in a lab from stem cells.

According to a new study by researchers at University of Melbourne, prolonged stem cell cultures are subjected to a relatively significant risk of mutation, similar to those seen in human cancers. Their results is of capital importance as it shows that lab grown cell treatment might become useless, if left to “stir” for too long.

The scientists studied 138 stem cell lines of diverse ethnic backgrounds – 127 Human embryonic stem (HES) cell lines and 11 induced pluripotent stem (iPS) cell lines.  These human pluripotent stem cells are crucial for the development of regenerative medicine, which can basically allow for growing a whole new heart or liver, since they can be converted into any cell type in the body.

Most of the cell lines studied retained their original number of chromosomes, even at prolonged cultures, however it was observed that about 20 percent of the cell lines mutated as a result of amplifications of a specific region in chromosome 20.

“While it is reassuring that 75 percent of the stem cell lines studied remained normal after prolonged growth in the laboratory, detecting and eliminating abnormal cells is an absolute prerequisite for clinical use of stem cell products,” said Martin Pera, co-author of the paper and chair of stem cell science at the University of Melbourne.

The study’s provided data can be considered essential to evaluating  cells for potential therapeutic applications. The project was made possible thanks to a international collaborative network formed by 35 laboratories and 125 collaborators.

The findings are reported in the latest issue of the journal Nature Biotechnology

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First trial of embryonic stem cells in humans

In was is a historic day, US doctors have officially begun the first trial of using human embryonic stem cells, as a result of the green light they got from regulators. The controversial method has been on the table for quite a while, and now The Food and Drug Administration has given a license to Geron to use stem cells to treat people with spinal injuries. These cells have the potential of becoming virtually any cell needed, including nerve cells.

Geron, the corporation who will lead this pivotal research is based in “silicon valley”, has spent 170 million dollars to develop a treatment for spinal cord injuries and reported that after the stem cell treatment, paralyzed rats regained some of their movement. However, it is still not yet clear how well people will respond to this kind of treatment; researchers are optimistic and they have already started human trials.

“When we started working with human embryonic stem cells in 1999, many predicted that it would be a number of decades before a cell therapy would be approved for human clinical trials. This accomplishment results from extensive research and development and a succession of inventive steps.”

And a great accomplishment it is ! Hopefully, this will be just the first step, and stem cells will be applied in other sorts of clinical trials too, because the huge potential they have cannot be neglected. Still, it will take some time to see results.

Professor Sir Ian Wilmut, director of the Medical Research Council Centre for Regenerative Medicine at the University of Edinburgh, said:

“This is very exciting news, however, it is very important to appreciate that the objective of trials at this stage is to confirm first of all that no harm is done to patients, rather than to look for benefits. Once that has been confirmed then the focus moves on to development and assessment of the new treatment.”

“This is indeed a significant milestone in our journey towards the promise of stem cell-based medicines. The global stem cell and regenerative medicine community will be awaiting the results of this safety trial with much anticipation.”, added Ben Sykes, executive director of the UK National Stem Cell Network