Amyotrophic lateral sclerosis (ALS), often referred to as Lou Gehrig’s disease, is a motor neuron disease that progressively attacks the central nervous system and eventually immobilizes those who have it. A new study published in the Journal of Clinical Investigation has identified a potential new target for the treatment of ALS.
Researchers at Harvard Medical School, Tufts Medical School, Brigham and Women’s Hospital and Massachusetts General Hospital have discovered a new potential biomarker that could help identify the stage of ALS in a patient with a blood test. They have also discovered that immune system response and inflammation has more to do with neural cell death associated with ALS than previously known.
Unlike multiple sclerosis (MS), ALS is typically not considered a neuroinflammatory disease. This study showed however, that the immune system response actually plays a big role in neural cell death. Clinical trials have previously shown that common anti-inflammatory drugs like those used to treat MS have been ineffective. It appears though that these drugs didn’t target the culprits. Using a genetically modified mouse model the researchers were able to identify the role of a particular type of white blood cell called a monocyte. They found that these monocytes are recruited to move to the spinal cord. This eventually leads to inflammation of spinal cord. Furthermore, with the introduction of these monocytes to the area, other “killer cells” become activated contributing to neural cell death. Interestingly, these monocytes were not recruited to the brain.
The researchers went on to target the specific monocytes of the mice with the mutant gene SOD1, the first gene to be associated with familial ALS, with antibodies and showed that they could slow the progression of the disease in the mice. They also found that humans with ALS showed a very similar monocyte signature as that of the SOD1 mice. The study concludes with the following statement:
“In conclusion, we demonstrate that recruitment of inflammatory monocytes into the CNS [central nervous system] plays an important role in ALS disease progression. Furthermore, we found that the inflammatory miRNA signature in peripheral monocytes from ALS subjects to be analogous to that observed in the spleen of SOD1 mice, providing a direct link between the mouse model and the human disease. Thus, the SOD1-like profile of monocytes in the blood of ALS patients we identified may serve as a biomarker linked to disease stage or progression and modulation of these cells is a potential therapeutic approach.”
In an ALS Association press release, Lucie Bruijn, Ph.D. Chief Scientist for The ALS Association said, “This new biomarker provides us with a tool to better understand the beginning stages of ALS and may allow us to track the disease with a simple blood test…That is critical for developing new treatments. Furthermore, the immune system changes identified in this study may themselves offer new targets for treating ALS.”
For more information about ALS and how you can help defeat it, visit the ALS Association’s website at http://www.alsa.org.