Posted on 04/06/2017 10:06:58 AM PDT by Red Badger
Investigators at the Ted Rogers Centre for Heart Research have discovered a surprising new role for tumor necrosis factor (TNF): namely, that it is a major regulator of small blood vessel function, the key determinant of blood pressure. The study is published online today in Nature Communications.
TNF has long been tied to inflammation, giving rise to the use of anti-TNF medications for chronic inflammatory diseases such as rheumatoid arthritis, psoriasis and IBS. Now, after years of studying TNF's cell signaling functions in the vascular system, researchers found that TNF directly impacts how the smallest arteries constrict - and thus profoundly influences blood pressure.
"This new role for TNF re-brands the traditional cytokine and firmly places it as a central regulator of microvascular myogenic responsiveness, one of the most important known regulatory mechanisms in the cardiovascular system," said Jeff Kroetsch, lead author of the study.
This is the first study to suggest that TNF may help regulate blood pressure. Kroetsch and his colleagues demonstrate that TNF uses a known, but unconventional mechanism, to regulate blood vessel constriction. Instead of activating a conventional "forward signal" through TNF receptors, TNF in the vascular wall initiates a "reverse signal" that directly travels into the contractile smooth muscle cells. This study is the first to demonstrate that such a reverse signal regulates a key physiological process outside of the immune system. This new function for vascular TNF holds true across several species, including humans, suggesting that this mechanism has been conserved through evolution.
Impact on those with inflammatory disease
While an early study, this work suggests that anti-inflammatory drugs targeting TNF could have negative side effects on blood pressure control - a danger that escalates for anyone with a cardiac condition such as heart failure.
"This new role for TNF underlines the need for caution when administering anti-TNF therapeutics, as they could lead to unpredictable blood pressure responses and increase cardiovascular stress," said Steffen-Sebastian Bolz, a Ted Rogers Centre principal investigator, University of Toronto professor of physiology, and Kroetsch's supervisor.
"We suggest that patients taking anti-TNF therapies be continuously monitored and treatment terminated if blood pressure disturbances are observed," Bolz added.
Kroetsch and collaborators found that in small resistance arteries, TNF acts as "mechanosensor" that senses changes in blood pressure. TNF then conducts biochemical signals that affect how the arteries constrict. They observed that TNF controls blood pressure and that drugs that interfere with TNF signaling can dramatically reduce blood pressure.
The ramifications of this research may stretch into other systems in the body.
"Since TNF is expressed in virtually all cells, and they are all sensitive to mechanical forces, this discovery potentially applies to tissues and cell types well beyond the cardiovascular system," Kroetsch said. "Future research may yield insight into other vital processes in the body that are influenced by TNF."
Explore further: Why do we develop high blood pressure?
More information: Jeffrey T. Kroetsch et al, Constitutive smooth muscle tumour necrosis factor regulates microvascular myogenic responsiveness and systemic blood pressure, Nature Communications (2017). DOI: 10.1038/ncomms14805
Journal reference: Nature Communications
Paying too much attention to politics.
Thanks for posting. As one of many who suffer HBP and Chronic Kidney Failure, this and the linked article also on HBP are of great interest.
Bump for Susan Rice, John Bremer, FBI Dir Comey, and Hussein Obama. They are finding HBP is caused by another factor, TRUTH.
Interesting article that I am going to show my primary care physician. She and another specialist have been baffled on why my blood pressure is very high without medications even though I didn’t exhibit causes of high blood pressure (lack of exercise, smoking, alcohol consumption, excess salt consumption, etc.).
Probably genetic....................
> Why do we develop high blood pressure?
I had to get a medical note in 1962 to enlist in the Navy.
My blood pressure was 78/50 and my pulse rate was 45.
It’s the same today as it was 55 years ago.
My doctor hates it because it’s not on the charts and he can’t look up stuff about me.
All members of my family have similar physiology.
I don’t know what high blood pressure is, but I’m pretty sure I don’t have it.
“Probably genetic....................”
Could be. Some members of my family have high BP although none as high as mine. Other exhibit normal or even low BP.
What is interesting is I felt fine with the higher BP and more lethargic when my BP was more normal (with meds). But I won’t take chances so I follow a strict regimen regarding taking the meds.
>>>Why do we develop high blood pressure?
Paying too much attention to politics<<<
It’s a miracle that there are any FReepers over 60 Years Old. #;^)
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How many FReepers do you think there are under 60?
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When my MIL was in her 60’s, her doctor insisted she wouldn’t live the year out of she didn’t take BP meds. She refused to take them because they made her feel tired. So, she dumped the doctor, and the meds. To this day she refuses to take meds of any kind.
She will be 103 in May of this year.
>>>How many FReepers do you think there are under 60?<<<
I’m sure there are more than a couple but less than a few.
Time for an FR Survey? LOL
Hats off to your MIL.
My 63 year old friend suffered a near death stroke because he did not take his all his meds. I am not taking any chances.
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>> “conserved through evolution.” <<
What absurdity! it is just another solid argument for “Intelligent Design” and undermines evolution.
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Take a break....step away.
Great story. God bless her.
You are lucky to have her so long.
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Your 63 year old friend suffered a near death stroke because he took “medications.”
Strokes are one of the most mentioned “side effects” of drugs advertised on TV.
Have you ever listened to the stuff they babble softly and rapidly in those commercials?
Drugs are probably the major cause of death in this country.
There are safer, more effective natural remedies for literally everything.
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A solid majority.
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Your MIL has it exactly right!
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Then there is this http://drjasongonzales.com/2015/10/23/autonomic-nervous-system-the-key-to-resolving-chronic-health-issues/
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