Acrolein, a pollutant found in car exhaust, cigarette smoke and even burning candles, may have a role in causing multiple sclerosis. Even though the research is preliminary, involving mice infected with an MS-like disease, the prospect is compelling. It's the first time scientists have found a cause for MS, a condition that affects about 350,000 in the U.S. alone.
Additionally, researchers were able to reduce the amount of acrolein in the mice by treating them with hydralazine, a drug approved by the FDA for hypertension (high blood pressure). Hydralazine, also known by its brand name, Apresoline, delayed the onset of the disease in mice and reduced the severity of symptoms.
Research at Purdue
A team of scientists led by Riyi Shi, a medical doctor and a professor of neuroscience and biomedical engineering at Purdue University, observed that mice infected with a disease similar to multiple sclerosis had highly elevated levels of acrolein in their spinal cords – about 60 percent more than mice without the disease.
The finding is significant because it is the first concrete laboratory evidence that there's a link between acrolein and MS.
Acrolein from the environment is known to damage nerve cells, and it is also produced within the body after nerve cells are damaged. Previous studies by the same research team at Purdue had found that neuronal death caused by acrolein can be prevented with hydralazine.
Furthermore, "the treatment did not cause any serious side effects in the mice," Shi said. "The dosage we used for hydralazine in animals is several times lower than the standard dosing for oral hydralazine in human pediatric patients. Therefore, considering the effectiveness of hydralazine at binding acrolein at such low concentrations, we expect that our study will lead to the development of new neuroprotective therapies for MS that could be rapidly translated into the clinic."
Acrolein's Environmental Damage
Shi said that acrolein induces the production of free radicals, compounds that cause oxidative damage to tissues (which is why the antioxidants found in fresh fruits and vegetables are so important to a strong immune system).
Other researchers had previously shown that acrolein damages liver cells and that the damage can be alleviated by hydralazine, leading the Purdue researchers to study its possible effects on spinal cord tissues.
An online paper planned for the journal Neuroscience will outline efforts by the researchers to discover how hydralazine binds to acrolein and neutralizes it. That finding could lead to synthetic drugs that have fewer side effects.
If hydralazine or a synthetic is approved for treatment of MS symptoms, it would likely be administered over a long period of time, as are other MS drugs.
MS and Mice
Still, it is a long way from a mouse model to a drug that can be used on humans. Such a treatment may be years away, as is also the case with another famous mouse experiment
In 2009, researchers at the Jewish General Hospital Lady Davis Institute for Medical Research and McGill University in Montreal used mice to test an experimental MS treatment that completely reverses the autoimmune disorder in mice. That treatment, known as GIFT15, works by suppressing the immune system using naturally occurring proteins that normally stimulate the nervous system. When fused together in the lab, the two proteins form a compound that has the opposite effect of the individual proteins. When combined with immune system B-cells from the mice, the compound works to calm the immune system.
The effect of GIFT15 on the mice was immediate: their MS-like symptoms were reversed. It was as if they had never had the disease. As one of the researchers put it, "when we gave [the GIFT15-treated B-cells] back intravenously to mice ill with multiple sclerosis, the disease went away."
MS is a complex, unpredictable and debilitating disease. Long years of study of the symptoms and possible causes of MS are bringing advances in therapy and may one day result in a cure.
References and Further Reading:
Purdue University News Service. "Findings Suggest New Cause, Possible Treatment for Multiple Sclerosis," November 23, 2010 (accessed November 24, 2010).
Science Daily "Multiple Sclerosis Successfully Reversed in Mice," August 12, 2009 (accessed November 24, 2010).
"Are you Damaging Your Health by Burning Candles at Home?"
Fran Gardner - Fran Gardner is a writer and editor who lives in Portland, Oregon. She retired in 2008 from The Oregonian, a big newspaper in town. She ...
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