Sugar can delay neurodegeneration caused by enzyme deficiency

A team of researchers from Baylor College of Medicine in the US have found that a new therapeutic approach of using simple sugar can help in delaying neurodegeneration associated with disease mucopolysaccharidoses IIIB (MPS IIIB).

Neurodegeneration is caused due to abnormal accumulation of essential cellular molecules called mucopolysaccharides.

The team researched on alternative ways to improve the cell’s ability to clear this accumulation of mucopolysaccharides. They tested their approach on a mouse model of MPS IIIB.

In the journal Autophagy, the researchers reported that sugar trehalose enhances cellular waste disposal thereby improving the neurological symptoms in a mouse model.

Baylor College of Medicine molecular and human genetics assistant professor Dr Marco Sardiello said: "In the case of MPS IIIB, a mutation on a gene that codes for a lysosomal enzyme that breaks down a cellular material called heparan sulfate, renders the enzyme ineffective.

"Consequently, the lysosome cannot do its work of degrading heparan sulfate to either discard it or recycle it, and the material accumulates."

"In the case of MPS IIIB, a mutation on a gene that codes for a lysosomal enzyme that breaks down a cellular material called heparan sulfate, renders the enzyme ineffective."

The accumulation of heparan sulfate in lysosomes can lead to degeneration of brain tissue among infants.

They start showing behavioural issues, aggressiveness and sleep disturbances, as well as loss of vision and hearing. Gradually, they become immobile and usually do not live more than 20 years.

Various treatments strategies are currently being tested on animal models by administering fully working enzyme to eliminate enzyme deficiency.

Unlike these strategies, the researchers here used a non-traditional approach on a mutated mouse, which exhibits similar clinical symptoms observed in patients such as progressive neurodegeneration, loss of vision and shorter lifespan.

Under the test, one group of MPS IIIB mice were treated with trehalose in the drinking water and the other group did not receive the sugar.

The normal mice without the mutation were provided water with or without trehalose as controls.

After observing them for 11 months, the researchers found that the MPS IIIB mice treated with trehalose lived longer, showing several delayed neuropathological features compared to other mice.