Diabetics use human insulin produced in bacteria in order to treat their metabolic disorder. Many other genetically engineered proteins are also on the advance. They are being used for diagnosis as well as for therapy.
Whereas insulin used to be extracted from slaughterhouse waste, today it is produced genetically in bacteria. However, more complex proteins have to be synthesised in more complex organisms. This takes place mostly in bioreactors using animal cell lines. Biotechnologist Prof. Ralf Reski from Freiburg, Germany, has developed the moss Physcomitrella patens into a safe and inexpensive alternative supplier of medicine.
His group has now, under Dr. Eva Decker, for the first time succeeded in producing a human protein in a moss bioreactor, which has been assigned the "orphan drug" status by the respective EU authorities. This means the development and approval of such medication receive particular support from the authorities. In many people the amount of this protein decreases with old age - with severe consequences. Eva Decker explains: "With the complement factor H we have produced a protein in moss that otherwise occurs only in blood and is important for the immune system. Not enough of this protein in older people is the main cause of blindness for 50 million people worldwide. This age-related macular degeneration (AMD) is a problem, particularly in industrialised countries."
Biochemists from the Freiburg Centre for Systems Biology under Dr. Andreas Schlosser were able to show with the help of high-performance mass spectrometers that the human factor H engineered into and produced by moss was a complete protein. Infection biologists headed by Prof. Peter F. Zipfel from the Hans-Knöll-Institute in Jena, Germany, were able to prove in biological assays that factor H from moss is fully functional. "Currently factor H is not available in pharmacies, so treatment for AMD with this protein is not possible. To date recombinant production of factor H was barely feasible. I am convinced that for the first time the moss bioreactor is a promising option", says Peter Zipfel.
This work was supported by the German Federal Ministry of Education and Research (BMBF), the Freiburg Initiative for Systems Biology and the Cluster of Excellence BIOSS.
Dr. Annette Büttner-Mainik, first author of the publication, was a Kekulé scholarship holder from the endowment fund of the German Chemical Industry (FCI).
The title of the original publication is: Annette Büttner-Mainik, Juliana Parsons, Hanna Jérôme, Andrea Hartmann, Stephanie Lamer, Andreas Schaaf, Andreas Schlosser, Peter F. Zipfel, Ralf Reski, Eva L. Decker (2010): Production of biologically active recombinant human Factor H in Physcomitrella. Plant Biotechnology Journal, doi: 10.1111/j.1467-7652.2010.00552.x.
"It will take a while before medication produced in moss is available in pharmacies", says Ralf Reski, member of the Innovation Think Tank of the governor of Baden-Wuerttemberg. "We are further optimising the moss bioreactor using methods from Systems Biology and Synthetic Biology. However, the implementation of clinical studies and the setting up of industrial production is long-winded and expensive; this is the task of industry and not of university research."
Tuesday, July 27, 2010
Tuesday, July 20, 2010
Stem Cell Transplants Stalled Blindness in Rats
Researchers say putting nerve stem cells from StemCells Inc near the retinas of rats with a form of macular degeneration helped keep the disease from advancing to blindness for several months.Nerve stem cell transplants may help slow the progression of macular degeneration, the most common cause of blindness in the developed world, U.S. researchers said on Monday.
They said putting nerve stem cells from StemCells Inc near the retinas of rats with a form of macular degeneration helped keep the disease from advancing to blindness for several months.
"These cells improve the chemical environment in the back of the eye," said Ray Lund of the Casey Eye Institute at Oregon Health & Science University in Portland, whose findings were presented at the Society for Neuroscience meeting in Chicago.
Lund said the mechanism is not clear, but he suspects that when immature nerve cells are placed near the retina, they produce growth factors that protect the cells from damage by the disease.
"It's basically a chemical pump that is sitting in the right place and producing the right things," Lund said in a telephone interview.
Where normally animals with eye disease lost their vision by three months old, rats that got the transplants kept their vision for at least seven months, he said.
"There is no evidence that they (the transplanted cells) do any damage," Lund said, adding that the animals do not develop tumors, a key worry for stem cell transplants.
The findings raise hope for use of the treatment in humans with a range of diseases in which the retina become damaged, including age-related macular degeneration or AMD, which affects nearly 30 million people worldwide, including 15 million Americans.
People with AMD lose central vision when delicate light-sensing cells of the macula, a region at the center of the retina, become damaged.
In the rats, the researchers transplanted immature nerve cells into the space near the retina. Lund said the same could be done in people with retinal disease.
Dr. Stephen Huhn, head of the Central Nervous System research program at StemCells Inc, said the cells are adult neural stem cells. He said they are multipotent, meaning they can morph into different types of nerve cells.
The company has already tested the treatment in a study of six patients with Batten's disease, a fatal inherited disorder of the nervous system.
"Having a cell that has already entered clinical testing that has been well tolerated at very high doses in the brain gives us a lot of confidence about exploring the same type of strategy in the eye," Huhn said.
Huhn said he thinks the cells may be especially well suited for use in the retina, brain and spinal cord, which are less likely to reject the cells than other parts of the body.
Ultimately, he said the hope is to develop a treatment for the dry form of macular degeneration, which affects around 90 percent of patients diagnosed with AMD. No treatments are available for this form of the disease.
Huhn said treating this form of the disease may prevent some people from developing wet AMD, in which tiny new blood vessels grow between the retina and the back of the eye.
This form of the disease can be treated with modern drugs like Lucentis, from Novartis and Roche's Genentech, and Pfizer's Macugen.
They said putting nerve stem cells from StemCells Inc near the retinas of rats with a form of macular degeneration helped keep the disease from advancing to blindness for several months.
"These cells improve the chemical environment in the back of the eye," said Ray Lund of the Casey Eye Institute at Oregon Health & Science University in Portland, whose findings were presented at the Society for Neuroscience meeting in Chicago.
Lund said the mechanism is not clear, but he suspects that when immature nerve cells are placed near the retina, they produce growth factors that protect the cells from damage by the disease.
"It's basically a chemical pump that is sitting in the right place and producing the right things," Lund said in a telephone interview.
Where normally animals with eye disease lost their vision by three months old, rats that got the transplants kept their vision for at least seven months, he said.
"There is no evidence that they (the transplanted cells) do any damage," Lund said, adding that the animals do not develop tumors, a key worry for stem cell transplants.
The findings raise hope for use of the treatment in humans with a range of diseases in which the retina become damaged, including age-related macular degeneration or AMD, which affects nearly 30 million people worldwide, including 15 million Americans.
People with AMD lose central vision when delicate light-sensing cells of the macula, a region at the center of the retina, become damaged.
In the rats, the researchers transplanted immature nerve cells into the space near the retina. Lund said the same could be done in people with retinal disease.
Dr. Stephen Huhn, head of the Central Nervous System research program at StemCells Inc, said the cells are adult neural stem cells. He said they are multipotent, meaning they can morph into different types of nerve cells.
The company has already tested the treatment in a study of six patients with Batten's disease, a fatal inherited disorder of the nervous system.
"Having a cell that has already entered clinical testing that has been well tolerated at very high doses in the brain gives us a lot of confidence about exploring the same type of strategy in the eye," Huhn said.
Huhn said he thinks the cells may be especially well suited for use in the retina, brain and spinal cord, which are less likely to reject the cells than other parts of the body.
Ultimately, he said the hope is to develop a treatment for the dry form of macular degeneration, which affects around 90 percent of patients diagnosed with AMD. No treatments are available for this form of the disease.
Huhn said treating this form of the disease may prevent some people from developing wet AMD, in which tiny new blood vessels grow between the retina and the back of the eye.
This form of the disease can be treated with modern drugs like Lucentis, from Novartis and Roche's Genentech, and Pfizer's Macugen.
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