Soluble TNF receptors, which block TNF's "bad" action, already are being used to treat rheumatoid arthritis, in which the immune system attacks joints. MCG researchers have found that blocking this site does not block the positive-action, sugar-binding site. "That means we have a physiologically relevant form of this peptide in our body, a cytokine that could help us avoid the problems that lead to ischemic reperfusion injury," Dr. Lucas said. Next he will study whether that natural site can be revved up instead of giving a synthetic peptide. He also wants to explore the synthetic peptide's potential in diseases such as diabetes-associated vascular problems as well as with other types of organ transplants.

The synthetic peptide can act like a lectin, big proteins that bind to sugar. Just how this sugar-binding activates sodium uptake is something he's still studying. But he knows the sodium channel effect is important because when he blocks it, the positive effect of the synthetic peptide is lost.

He also wants to know the peptide's long-term impact, including its effect on neutrophils. If it continues to suppress their infiltration, the peptide also could have potential for chronic transplantation problems, including organ rejection, he said.

Collaborators for this study include Drs. Stephen Black and Sanjiv Kumar at the Vascular Biology Center, who helped with lung endothelial cell studies and measuring reactive oxygen species levels; Dr. J-rg Hamacher, pulmonologist and transplant surgeon at the University Hospital of Bern, Switzerland, who performed the lung transplants; and MCG postdoctoral fellow Dr, Guang Yang.

Three-year survival rates for lung transplants are about 64 percent and about 20,000 lung transplants have been done in the United States since the first successful single-lung transplant in 1983. Primary reasons for lung transplants include chronic obstructive pulmonary disease, pulmonary fibrosis, cystic fibrosis and lung cancer. As with most types of transplants, donors lungs are in short supply, so the mean wait time is about four years, which means many patients die waiting.

Source: Medical College of Georgia