Brain's immune cells key to maintaining blood-brain barrier

[natasa778]

New research shows that the cells responsible for protecting the brain from infection and inflammation are also responsible for repairing the system of defenses that separates the brain from the rest of the body.

...
The new study, which was published today in the Proceedings of the National Academy of Sciences, reveals that the brain's immune system, specifically cells called microglia, play a central role in the process of repairing damage to the BBB.

...
Performing experiments in mice, Nedergaard and her colleagues observed that when small holes where made in the BBB, nearby microglia were rapidly mobilized and set about repairing the breach. In most instances, the integrity of the BBB was restored within 10 to 30 minutes.

The team identified a receptor called P2RYX12 that was responsible for activating the microglia and directing them to the site of the damage. This finding is significant because the same receptor is also present on platelets and is one of the targets of blood thinning drugs such as Plavix.

http://medicalxpress.com/news/2016-01-brain-immune-cells-key-blood-brain.html#nRlv

 

[lansbergen]

To me that means do not inactivate microglia

 

[Seven7]

Why is it getting so activated in CFS? Is it that there is not good barrier?

 

[lansbergen]

Why is it getting so activated in CFS? Is it that there is not good barrier?

I think the barrier is attacked by the infectious agent or the immune response to it.

 

[halcyon]

Why is it getting so activated in CFS? Is it that there is not good barrier?

CNS infection is my vote.

 

[Hip]

To me that means do not inactivate microglia

I think it is a bit more complicated that that.

Microglia can activate into the neuro-destructive mode (= classical activation), which is the "kill" mode that destroys pathogens; or they can activate into the neuro-protective mode (= alternative activation), which is the mode that repairs tissue and heals the brain.

I imagine that if the microglia are repairing the blood-brain barrier, it will be the neuro-protective mode that is required.

Quite a few factors (including LPS and mold toxins) seem to switch microglia from the neuro-protective mode into the neuro-destructive mode. And I would guess that an ongoing CNS infection would promote the neuro-destructive mode.

More info at the bottom of this post.

 

[lansbergen]

Microglia can activate into the neuro-destructive mode (= classical activation), which is the "kill" mode that destroys pathogens; or they can activate into the neuro-protective mode (= alternative activation), which is the mode that repairs tissue and heals the brain.

Pathogens in neurons must be destroyed. How would you do that without damaging the cells?

 

[Hip]

Pathogens in neurons must be destroyed. How would you do that without damaging the cells?

Yes, but only if there are indeed pathogens present in brain cells such as neurons or glia that need to be destroyed.

But what if microglia were activated into the neuro-destructive mode not because of pathogens in brain cells, but because of factors such as mold toxins, which induce the neuro-destructive mode?

Or what if there were only relatively few brain cells infected with pathogens (ME/CFS brain autopsies examining enterovirus infections in the brain have found only a scattering of infected cells), but the microglial response to that infection was far stronger than was necessary, perhaps again due to mold toxins entering the brain, or due to immune phenomena such as microglial priming, that inappropriately amplifies and exaggerates microglial responses?

 

[lansbergen]

Or what if there were only relatively few brain cells infected with pathogens (ME/CFS brain autopsies examining enterovirus infections in the brain have found only a scattering of infected cells), but the microglial response to that infection was far stronger than was necessary,

Or what if the brain is infected with a pathogen for wich is not tested?

 

[roller]

destroy lps and exotoxins/endotoxins produced by bacteria - then less microglia activation.

but... even then.. its not really clear, if this reduced response (due to waste reducation) wouldnt be benefical to the bacteria/pathogens itself.

we cannot solve this. so, we have to attack the pathogen.