• Maligned molecule found to have beneficial anti-inflammatory effect

By Daily Mail Reporter

PUBLISHED:05:43 EST, 3 August 2012 | UPDATED:06:11 EST, 3 August 2012

A molecule that causes Alzheimer’s disease could reverse paralysis caused by multiple sclerosis (MS), a study has found.

The much-maligned molecule, known as A-beta, has until now been known as the chief culprit behind Alzheimer’s.

But it is also found in multiple-sclerosis lesions, which occur when immune cells invade the brain and spinal cord and attack the insulating coatings of nerve cells.

The nerve signals then get mixed up  leading to blindness, loss of muscle control and difficulties with  speech, thought and attention

Scientists from Stanford University in the United States wanted to investigate the role the molecule played in MS.

They used a mouse model that mimics several features of the disease – including the autoimmune attack on myelinated sections of the brain. They then injected A-beta into the rodent’s belly.

The scientists had suspected the injection would exacerbate the MS, but the opposite happened.

 In mice whose immune systems had been ‘trained’ to attack myelin, which usually results in paralysis, A-beta injections delivered before the onset of symptoms prevented, delayed and even reversed paralysis.

This shows that when A-beta is injected outside the brain it moderates and can even reverse symptoms of MS and does not cause Alzheimer’s in the mouse.

The researchers believe the startling discovery will open new avenues in the fight against MS, a hugely debilitating condition which affects around 100,000 people in the UK.

Effect of MS on the brain: This CT scan shows patches of scar tissue in white, which damage the nervous system Effect of MS on the brain: This CT scan shows patches of scar tissue in white, which damage the nervous system

Laboratory tests also showed that A-beta countered not only visible symptoms such as paralysis, but also the increase in certain inflammatory molecules that characterises multiple-sclerosis flare-ups.

Lawrence Steinman, an MS expert and lead author of the report, which is published Science Translational Medicine, said: ‘This is the first time A-beta has been shown to have anti-inflammatory properties.’

Lennart Mucke, director of the Gladstone Institute of Neurological Disease in San Francisco and a veteran Alzheimer’s researcher, noted that while A-beta is toxic in the brain, it can have a very different effect elsewhere in the body.

He said: ‘A-beta is made throughout our bodies all of the time. But even though it’s been studied for decades, its normal function remains to be identified.

‘Most intriguing, to me, is this peptide’s potential role in modulating immune activity outside the brain.

‘There probably is a multiple-sclerosis drug in all this somewhere down the line,’ he said.