Nature sub-journal interpretation: Cholesterol recycling may help support myelin repair!

Like a string of beads, cholesterol- and lipid-rich myelin is covered in nerve fibers and kept insulated, isolating and effectively transmitting impulses.
We all know that a bunch of beads breaks, but only if they can't be reused, damage the vacuum cleaner, and stay on the floor permanently.
this is common in chronic brain lesions, where myelin disappears permanently, while small glial cells closely related to macrophages are scavenger cells in the brain, like the vacuum cleaners mentioned above.
In a person's lifetime, a single myelin is replaced, and during normal regeneration, scavenger cells ingest cholesterol and other lipids from the defective myelin so that they can be recycled and used to repair tissue, an efficient repair mechanism that can continue to occur in healthy individuals.
The synthesis of cholesterol supports the recycling of cholesterol In the article, researcher Saher and colleagues investigated the key role of cholesterol and other lipids in the body's nervous system in physiological and pathological conditions, and by conducting a joint study, the researchers investigated how multiple cell types in the brain treat cholesterol during myelin regeneration.
The researchers used genes to knock out the cholesterol synthesis process in a cell type in the brains of mice, and then studied the effects of this process on the brain myelin regeneration of mice, and found that mutant mice with cholesterol synthesis defects in scavenger cells in the brain behaved in a way that surprised scientists that they were still able to absorb cholesterol from degraded myelin but could not recover it.
And because many small glial cells can be converted into foam cells and eventually die from eating too much cholesterol, myelin's ability to regenerate is significantly reduced, so researchers wanted to know why phagocytoids block the production of re-used cholesterol.
researchers say a cholesterol synthesis intermediate called desmosterol is particularly important for the degradation and reconstruction of myelin membranes from degradation to regeneration, as a signaling molecule that not only causes cholesterol to mobilize to form a new myelin, but also helps to create a regenerative environment.
by using the early intermediate of cholesterol synthesis, squalene, can support the cholesterol synthesis process rationally, thus promoting the endogenous circulation of myelin.
In this study, researchers studied mice to reveal that terpene or can be used as a new potential factor in therapy to help treat myelin diseases such as multiple sclerosis;
: Berghoff, S.A., Spieth, L., Sun, T. et al. Microglia facilitate repair of demyelinated lesions via post-squalene sterol synthesis. Nat Neurosci 24, 47–60 (2021). doi:10.1038/s41593-020-00757-6 【2】Cholesterol recycling supports myelin repair by Max Planck Society。