Pig-to-Human Transplants Are Closer Than Ever

Two scientists at the Thomas E. Starzl Transplantation Institute at the University of Pittsburgh discussed the state of xenotransplantation--the use of cells, organs, or tissue from one animal in another--in a review in The Lancet. In that review, they touch on the history of one particular subject: pig-to-human transplants. Their conclusion? Clinical trials of pig-to-human transplants could begin in just a few years.

Pigs that are genetically modified with genes to protect their organs and other inside bits from attack by the human immune system are capable of all kinds of potentially life-saving effects. Research has been conducted until now with non-human primates, and while these primates have not been able to survive for all that long with pig organs--at best, a pig heart-implanted primate survives for around eight months--that could be enough time to serve as temporary lifesavers. Cells and tissue could be used to counteract human diseases like diabetes (as in this example) and Parkinson's, and have actually shown more success than complete organs.

The paper concludes by saying:

With new genetically modified pigs becoming available that are likely to improve the outcome of cellular and corneal xenotransplantation further, we believe that clinical trials will be justified within the next 2-3 years. No safety concerns that would prohibit such clinical trials have been reported...With regard to pig tissues and cells, as opposed to organs, it would seem that clinical xenotransplantation could soon become a reality.

The scientists believe that soon enough, genetically-modified pig organs could be even more capable than mechanical versions, which is surely great news for those who need them.

 by "environment clean generations"

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Posted in: biology,genetically modified pigs,human,pig,transplants,University of Pittsburgh

Enviropig: A Bioengineered Pig

Fresher Water Elevated phosphorus levels in water, often traceable to pig-waste runoff, are a major contributor to algal blooms that steal oxygen from fish and render drinking water toxic. This little piggy went to market. This little piggy stayed home. And this little piggy is genetically modified to poop less phosphorus, making it the most environmentally friendly pig in the world.

Like all animals, pigs' cells need phosphorus to make DNA, build cell membranes, and transport energy. But pigs can’t digest phytate, a phosphorus-heavy molecule in grains, so farmers fortify pig feed with pure phosphate or phytase, an enzyme that breaks usable phosphate off phytate. Still, pigs excrete nearly all the phosphorus they eat, and this washes into the ocean, where it feeds bacteria and algae that create oxygen “dead zones,” a major killer of marine wildlife.

The Enviropig is the first swine (a Yorkshire, to be exact) able to digest phytate on its own. The project started a decade ago when Cecil Forsberg, a biologist at the University of Guelph in Ontario, genetically modified pigs so that their salivary glands would secrete phytase. This allows the pigs, now in their eighth generation, to get their phosphate from grains alone, and to excrete about 40 percent less of it.

Switching to Enviropig herds will be expensive for farmers, Forsberg says, but in the long run subtracting supplements will save $1.75 per pig annually—a windfall for a 100,000-pig farm. He is currently petitioning the U.S. Department of Agriculture and Health Canada for permission to serve Enviropig meat. “Unfortunately, it is illegal for us to do taste tests at this time, despite the temptation,” he says. “But I expect they’ll taste quite good.”

Inside the Enviropig

1. Make the enzyme
As the pig chews, the Escherichia coli genes implanted in its salivary glands begin promoting phytase production.

2. Break up the pollutant
Phytase begins breaking phytate into digestible phosphate in the mouth, but it really ramps up its activity when it hits the stomach’s strong acid.

3. Poop and pee away!
Because they don’t need phosphate supplements, Enviropigs excrete 30 to 65 percent less phosphorus.

 by "environment clean generations"

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Posted in: environment,enviropigs,molecule,oxygen,pig,pollutants