Carbon Monoxide Protects Mice From Multiple Sclerosis

Science Daily — Multiple sclerosis (MS) is a chronic inflammatory 

disorder that causes degeneration of the nerves in the brain and 
spinal cord, leading to various symptoms including muscle weakness 
and pain. Most individuals with MS go through cycles of disease and 
remission, leading to the suggestion that there are regulatory 
mechanisms that counter the disease-causing inflammation.

Using a mouse model of MS (known as EAE), researchers from the 
Gulbenkian Institute in Portugal show that increased expression of a 
protein known as HO-1, as well as administration of carbon monoxide, 
protect mice from disease.

In the study, which appears online in January in advance of 
publication in the February print issue of the Journal of Clinical 
Investigation, Miguel Soares and colleagues show that mice lacking 
HO-1 develop more severe EAE than wild-type mice. Conversely, in mice 
already suffering the symptoms of EAE, disease is reversed if HO-1 
expression is induced.

The function of HO-1 is to degrade excess heme (a component of many 
important cellular proteins) and one of the by-products of heme 
degradation is carbon monoxoide. Surprisingly, like the induction of 
HO-1 expression, administration of carbon monoxide to mice already 
suffering the symptoms of EAE decreased disease.

The authors therefore suggest that modulating HO-1 expression or 
administering carbon monoxide might be useful therapeutic strategies 
to treat patients with MS.

Note: This story has been adapted from a news release issued by 
Journal of Clinical Investigation.