GIFU — Researchers have pinpointed a protein which could slow the development of amyotrophic lateral sclerosis (ALS), a degenerative disease of the nerve cells that gradually causes muscle weakness and atrophy.

The announcement by a research team at Gifu Pharmaceutical University headed by Hideaki Hara, a professor of molecular pharmacology, could lead to the development of new drugs and early diagnosis of the disease.

The researchers published their findings in the August 13 online edition of Scientific Reports.

The protein under study is called transmembrane glycoprotein NMB (GPNMB).

The researchers said they induced a greater prevalence in mice of mutated genes of the superoxide dismutase (SOD1) enzyme which is believed to be a cause of ALS. The mice were found to have greater than normal levels of GPNMB.

The mice were further induced to have a greater prevalence of GPNMB. ALS developed at a slower pace in those mice. Also, the rodents survived longer after developing the disease.

The researchers found that injecting GPNMB into the affected motor nerve cells led to an improvement in the functioning of the cells. They said the level of GPNMB in the blood serum and cerebral fluid of ALS patients also increased.

Those findings led the researchers to conclude a close relationship exists between GPNMB and the onset of ALS and its pathological condition, as well as the possibility that the GPNMB might prevent damage to motor nerve cells.

ALS develops in one or two individuals per 100,000 head of population ever year. Some 8,500 people have the disease in Japan.

Until now, diagnosis of ALS was made after it had already developed and other diseases were discounted.

The researchers hope to develop new drugs because the findings indicate that if the increase in GPNMB in ALS patients can be confirmed, diagnosis and early treatment might be possible before the full onset of the disease.

Hideki Nishitoh, a professor of biochemistry and molecular biology at the University of Miyazaki who has researched ALS for many years, said: “A major problem with ALS is that it kills off motor nerve cells. If a diagnosis can be made at an early stage, there is the possibility of starting treatment before the onset of the disease, which would be extremely effective in dealing with ALS.”

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