Researchers find that Nr4a1 expression in macrophages link the sympathetic and immune systems and limit inflammation during multiple sclerosis.
It is becoming more apparent every day that the different systems of the human body influence each other substantially more than what was previously thought. New research provides evidence that this is the case with the immune and sympathetic nervous systems. The linking factor is macrophages and a transcription factor they express, Nr4a1, and the result is affecting the outcome of multiple sclerosis.
Multiple sclerosis, or MS, is an immune mediated disease where the body’s immune cells attack the myelin protein that covers the neurons. Images of the central nervous system show large numbers of immune cells, such as macrophages and others, swarming the brain or spinal cord and leading to excessive inflammation. Nerves with damaged myelin fail to signal properly and thus affect the body’s ability to perform a large range of sensory related functions, such as seeing or walking. The intensity of the disease varies quite largely, from patients having mild symptoms that come and go, to paralysis or blindness. The exact triggers that cause MS are not known, and scientists are still trying to figure out the events that lead to the disease in an attempt to try to put an end to it early on before the damage is done.1
A new discovery about MS was published recently in Nature Immunology where a group of scientists found that in MS, macrophages link the sympathetic nervous system and the immune system and can affect the outcome of the disease. The main player is a transcription factor, Nr4a1, that is expressed in macrophages. Using a mouse model of MS, the researchers show that Nr4a1 expression in macrophages limits leukocyte infiltration and disease progression. As the scientists dug deeper, they found that Nr4a1 suppresses macrophage expression of nor-epinephrine – the main signaling molecule in the sympathetic nervous system, providing first evidence that the sympathetic nervous system and the immune system are connected.2
This study provides interesting new findings that can help the scientific community understand more about the onsets of MS and what factors are involved in disease progression. Here at HemaCare, where we supply macrophages to study MS and other inflammatory diseases, we are excited about these novel findings and will be watching eagerly as the scientific community unfolds more secrets about MS.
2 Shaked et al. (2015). Transcription factor Nr4a1 couples sympathetic and inflammatory cues in CNS-recruited macrophages to limit neuroinflammation. Nature Immunology, 16 (12). doi:10.1038/ni.3321.