Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cross-species transplant in rhesus macaques is step toward diabetes cure for humans

22.10.2007
With an eye on curing diabetes, scientists at Washington University School of Medicine in St. Louis have successfully transplanted embryonic pig pancreatic cells destined to produce insulin into diabetic macaque monkeys – all without the need for risky immune suppression drugs that prevent rejection.

The transplanted cells, known as primordia, are in the earliest stages of developing into pancreatic tissues. Within several weeks of the transplants, the cells became engrafted, or established, within the three rhesus macaque monkeys that received them. The cells also released pig insulin in response to rising blood glucose levels, as would be expected in healthy animals and humans.

"The approach reduced the animals' need for insulin injections and has promise for curing diabetes in humans," says senior investigator Marc Hammerman, M.D., the Chromalloy Professor of Renal Diseases in Medicine. "The transplants worked without a need for immune suppression and that is a major obstacle we have overcome."

The researchers' results appear online and will be published in the journal Xenotransplantation in November.

Although the transplants fell short of producing sufficient insulin to cure the macaques' diabetes, Hammerman predicts that with additional research, including the transplantation of additional embryonic pig cells into the animals, he will be able to reduce their need for insulin injections entirely.

The new research follows on the heels of reports by Hammerman and his colleagues demonstrating that transplanted pig pancreatic primordia can cure both type 1 and type 2 diabetes in rats, without using immune suppression drugs. Other scientists have tried different types of pancreatic cell transplants – in animals and humans – as a stepping stone to curing diabetes, but they all require anti-rejection drugs. These drugs must be taken daily to stave off rejection and have adverse effects of their own that limit the success of the transplants.

As a treatment for diabetes in people, pig insulin typically works as well as the human form. Before recombinant DNA technology enabled pharmaceutical companies to manufacture human insulin in the 1980s, pig and cow insulin were routinely given to diabetic patients.

The primates in the current study had type 1 diabetes, the form that occurs when islet cells in the pancreas stop producing insulin all together. The Washington University researchers transplanted 19 embryonic pig pancreatic primordia into each diabetic monkey. Each primordium is smaller than the diameter of a period that ends a sentence and is transplanted into a membrane that envelops the intestines and other digestive organs.

The transplanted cells were retrieved from the pig embryos early in their development, which is believed to render them "invisible" to the primates' immune system or induce a state of tolerance, either of which eliminates the need for immune suppression.

The researchers determined by multiple methods that the transplanted cells became established within the primates. And as the cells matured, they began to release pig insulin. "We found using every method that the cells engraft long-term and, thus, are not rejected by the animals' immune systems," Hammerman says. "It's been more than two years since our first transplant was carried out. That particular primate doesn't produce any primate insulin, but has pig insulin circulating in its bloodstream that has reduced by more than 50 percent the amount of injected insulin the animal needs, compared to levels before the transplant. The animals have never received immune suppression drugs."

Two of the macaques remain healthy. One, however, became anemic about six weeks post-transplant and was euthanized a month later after developing acute respiratory distress. The researchers could not find a link between this animal's illness and the pancreatic cell transplants.

The two remaining macaques have each received two transplants of embryonic pancreatic cells. One of the animals has been followed for 23 months after his first transplant, and the amount of insulin he needs to have injected has declined by some 55 percent over baseline levels. The other macaque has been followed for 10 months after his initial transplant, and his need for injected insulin continues to decline over time.

Hammerman and his colleague Sharon Rogers, research instructor in medicine, are leaders in the emerging field of organogenesis, which focuses on growing organs from transplanted embryonic organ precursors known as primordia. Unlike embryonic stem cells, which can become virtually any cell type, primordia are locked into becoming cells of a particular organ.

"We are encouraged by these results," Rogers says. "The absence of a need for immune suppression in diabetic rats gave us hope that we were on the right track. But many findings in rats do not hold true for species that are more closely related to humans, such as non-human primates. This one did."

The team will now determine how best to eliminate the need for injected insulin in the diabetic macaques that receive transplants, thus demonstrating long-term effectiveness of the technique, and establish the absolute safety of pancreatic primordia transplants. If these experiments succeed, the researchers plan to conduct clinical trials in humans with diabetes.

"We hope to find out how to apply our findings to human type 1 and type 2 diabetics because the embryonic pig primordia would represent an unlimited source of tissue for transplantation," Hammerman says.

Caroline Arbanas | EurekAlert!
Further information:
http://www.wustl.edu

Further reports about: Diabetes Embryonic Hammerman Insulin cure macaque month pancreatic primate primordia suppression

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>