By Cort Johnson, Health Rising, July 2024.
To read the full article please see https://www.healthrising.org/blog/2024/07/22/neuroinflammation-muscles-long-covid-chronic-fatigue-fibromyalgia/
THE GIST
- It’s always seemed that both the brain and the muscles must be involved in diseases like chronic fatigue syndrome (ME/CFS), fibromyalgia (FM), and long COVID. The question has always been how? A study just showed up could answer that question.
- It originates in the brain, can be triggered by infection, is associated with neuroinflammation, and impacts the ability of the muscles to produce energy (!). The new finding has birthed something called the brain-muscle axis.
- We’ve known for decades that the muscles are sending messages to the brain and affect things like energy metabolism, glucose metabolism, inflammation and bone formation.
- In this study, the authors introduced a variety of triggers (bacterial infections, the SARS-CoV-2 protein ORF3a, and the neurotoxic protein Aβ42 found in Alzheimer’s) to produce neuroinflammation in the brains of the ubiquitous fruit fly and mice.
- Note the interesting disease choices – Alzheimer’s and long COVID – two diseases that are rarely mentioned together but both of which feature what the senior author of the study called “deep muscle fatigue“.
- Each animal responded to the introduction of these substances with a clear increase in muscle fatigue and reduced endurance. Introducing these stressors into the brain triggered increased levels of reactive oxygen species (ROS), or free radicals which then triggered the production of the IL-6 cytokine, which then found its way to the muscles, where it turned on genes that turned down energy production.
- For the first time, inflammation in the brain was shown to reduce muscle mitochondrial activity and endurance dramatically. No exercise was needed to shut down the muscles. All it took was neuroinflammation.
- Noting that a lack of motivation does not play a role in this process, the senior author of the study stated: “This is more than a lack of motivation to move because we don’t feel well. These processes reduce energy levels in skeletal muscle, decreasing the capacity to move and function normally,”.
- While the study was done in fruit flies and mice, note that this pathway appears to be highly evolutionarily conserved; i.e. this core pathway is present in many species.
- Noting the large energy needs of the muscles, the authors proposed that when the brain is inflamed it may limit energy production by the muscles to give the brain more resources.
- The two key factors needed for this process to occur – neuroinflammation and increased IL-6 levels – have been found in ME/CFS, fibromyalgia, and long COVID.
- The authors proposed that IL-6 and Stat inhibitors could help, Avindra Nath has also proposed using JAK-STAT inhibitors in ME/CFS.
- We don’t know if this process is occurring in ME/CFS, FM and long COVID, but one suspects that whatever ends up causing these diseases will impact an evolutionarily conserved core pathway that can dramatically affect functionality.
- The good news is that a way to explain how neuroinflammation can directly impact energy production in the muscles has been found. The finding has received a lot of attention, and will undoubtedly hook in some Alzheimer’s researchers, and will undoubtedly be followed up on. The long-COVID/ME/CFS/fibromyalgia research world just got a bit richer and is bringing new potential treatment options to the table.