Washington, June 16 (Reuters): A cluster of 291 genes has been linked with asthma, and one gene especially provides a good target for new drugs, researchers said today.
The laboratory work needs to be confirmed in living asthma patients, but shows the disease is more complex and far-reaching than anyone believed, the international team of researchers said. “Each gene may represent a target for drug development,” Dr Marc Rothenberg, director of allergy and immunology at Cincinnati Children’s Hospital, said in a statement.
“But one gene in particular, arginase, regulates pathways that we think are critical in an asthmatic reaction,” added Rothenberg, who led the study.
Asthma is on the rise in industrialised countries. In the US alone more than 17 million people have asthma, and it kills 5,000 people a year. Asthma rates in children under the age of 5 rose more than 160 per cent between 1980 and 1994 — and no one is sure why.
Rothenberg’s study did not offer an immediate answer but he said arginase seemed to act as a kind of master control for asthmatic reactions.
“Regardless of the specific allergen, arginase seems to be involved.”
We hope to come up with a treatment for asthma by targeting arginase.”
Working with scientists in the US, Canada and Australia, Rothenberg’s team looked at genes first in mouse tissue, then compared their findings to human genes found in human tissue and published on the internet as part of the Human Genome Project.
A huge number of mouse genes — 6.5 per cent of the mouse genome — have altered function in an asthmatic lung, they reported in this week’s issue of the Journal of Clinical Investigation.
“These results are significant because they present a completely new approach to treating and diagnosing asthma,” Rothenberg said.
Arginase is an enzyme that breaks down arginine, an amino acid that people eat daily.
The body uses arginine to make growth factors, connective tissue proteins and nitric oxide.
In asthma, arginine seems to be broken down in an unusual way, the researchers have found.
Rothenberg said: “It’s our hope that the release of these results will fuel the pharmaceutical industry, as well as other researchers, to take new approaches in asthma research.”