Evidence in mice that electroacupuncture reduces inflammation via specific neural pathways



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A group of researchers led by neuroscientists at Harvard Medical School has efficiently used acupuncture to tame cytokine storm in mice with systemic inflammation.

In the examine, printed Aug. 12 in Neuron, acupuncture activated totally different signaling pathways that triggered both a pro-inflammatory or an anti-inflammatory response in animals with bacterially induced systemic inflammation.

Further, the group discovered that three components decided how acupuncture affected response: website, depth and timing of therapy. Where in the physique the stimulation occurred, how robust it was and when the stimulation was administered yielded dramatically totally different results on inflammatory markers and survival.

The group’s experiments signify a vital step towards defining the neuroanatomical mechanisms underlying acupuncture and supply a roadmap for harnessing the method for the therapy of inflammatory illnesses.

The scientists warning, nevertheless, that earlier than any therapeutic use, the observations should be confirmed in additional analysis—in animals in addition to in people—and the optimum parameters for acupuncture stimulation should be fastidiously outlined.

“Our findings represent an important step in ongoing efforts not only to understand the neuroanatomy of acupuncture but to identify ways to incorporate it into the treatment arsenal of inflammatory diseases, including sepsis,” mentioned examine principal investigator Qiufu Ma, professor of neurobiology in the Blavatnik Institute at Harvard Medical School and a researcher at Dana-Farber Cancer Institute.

In the examine, acupuncture stimulation influenced how animals coped with cytokine storm—the speedy launch of huge quantities of cytokines, inflammation-fueling molecules. The phenomenon has gained mainstream consideration as a complication of extreme COVID-19, however this aberrant immune response can happen in the setting of any an infection and has been lengthy identified to physicians as an indicator of sepsis, an organ-damaging, often-fatal inflammatory response to an infection. Sepsis is estimated to have an effect on 1.7 million folks in the United States and 30 million folks worldwide annually.

Acupuncture, rooted in conventional Chinese drugs, has lately grown extra built-in into Western drugs, notably for the therapy of continual ache and gastrointestinal problems. The method includes mechanical stimulation of sure factors on the physique’s floor—often called acupoints. The stimulation purportedly triggers nerve signaling and remotely impacts the operate of inner organs akin to specific acupoints.

Yet, the essential mechanisms underlying acupuncture’s motion and impact haven’t been totally elucidated.

The new examine is a crucial step in mapping the neuroanatomy of acupuncture, the analysis group mentioned.

As a neurobiologist who research the elemental mechanisms of ache, Ma has been curious in regards to the biology of acupuncture for years. He was intrigued by a 2014 paper which confirmed that utilizing acupuncture in mice may alleviate systemic inflammation by stimulating the vagal-adrenal axis—a signaling pathway in which the vagus nerve carries indicators to the adrenal glands—to set off the glands to launch dopamine. Ma’s curiosity was additional intensified by work printed in 2016 exhibiting that vagus-nerve stimulation tamed the exercise of inflammatory molecules and lessened signs of rheumatoid arthritis.

In the present examine, researchers used electroacupuncture—a contemporary model of the normal guide method that includes the insertion of ultra-thin needles just below the pores and skin in numerous areas of the physique. Instead of needles, electroacupuncture makes use of very skinny electrodes inserted into the pores and skin and into the connective tissue, providing higher management of stimulation intensities.

Building on earlier analysis pointing to neurotransmitters’ function in inflammation regulation, the researchers targeted on two specific cell sorts identified to secrete them—chromaffin cells that reside in the adrenal glands and noradrenergic neurons that are situated in the peripheral nerve system and straight related to the spleen by way of an abundance of nerve fibers. Chromaffin cells are the physique’s predominant producers of the stress hormones adrenaline and noradrenaline and of dopamine, whereas noradrenergic neurons launch noradrenaline. In addition to their well-established features, adrenaline, noradrenaline and dopamine, the researchers mentioned, seem to play a job in inflammation response—an commentary that’s been borne out in earlier analysis and is now reaffirmed in the experiments of the present examine.

The group needed to find out the exact function these nerve cells play in the inflammatory response. To accomplish that, they used a novel genetic device to ablate chromaffin cells or noradrenergic neurons. This allowed them to match the response to inflammation in mice with and with out these cells to find out simply whether or not and the way they had been concerned in modulating inflammation. The markedly totally different response in mice with and with out such cells conclusively pinpointed these nerve cells as key regulators of inflammation.

In one set of experiments, researchers utilized low-intensity electroacupuncture (0.5 milliamperes) to a specific level on the hind legs of mice with cytokine storm brought on by a bacterial toxin. This stimulation activated the vagus-adrenal axis, inducing secretion of dopamine from the chromaffin cells of the adrenal glands. Animals handled this manner had decrease ranges of three key kinds of inflammation-inducing cytokines and had higher survival than management mice—60 % of acupuncture-treated animals survived, in contrast with 20 % of untreated animals. Intriguingly, the researchers noticed, the vagus-adrenal axis might be activated by way of hindlimb electroacupuncture however not from stomach acupoints—a discovering that exhibits the significance of acupoint selectivity in driving specific anti-inflammatory pathways.

In one other experiment, the group delivered high-intensity electroacupuncture (three milliamperes) to the identical hindleg acupoint in addition to to an acupoint on the stomach of mice with sepsis. That stimulation activated noradrenergic nerve fibers in the spleen. The timing of therapy was vital, the researchers noticed. High-intensity stimulation of the stomach produced markedly totally different outcomes relying on when therapy occurred.

Animals handled with acupuncture instantly earlier than they developed cytokine storm, skilled decrease ranges of inflammation throughout subsequent illness and fared higher. This safety measure of high-intensity stimulation elevated survival from 20 to 80 %. By distinction, animals that obtained acupuncture after illness onset and through the peak of cytokine storm skilled worse inflammation and extra extreme illness.

The findings exhibit how the identical stimulus may produce dramatically totally different outcomes relying on location, timing and depth.

“This observation underscores the idea that if practiced inappropriately, acupuncture could have detrimental results, which I don’t think is something people necessarily appreciate,” Ma mentioned.

If borne out in additional work, Ma added, the findings recommend the likelihood that electroacupuncture may at some point be used as a flexible therapy modality—from adjunct remedy for sepsis in the intensive care unit to extra focused therapy of site-specific inflammation, resembling in inflammatory illnesses of the gastrointestinal tract.

Another doable use, Ma mentioned, could be to assist modulate inflammation ensuing from most cancers immune remedy, which whereas lifesaving can typically set off cytokine storm resulting from overstimulation of the immune system. Acupuncture is already used as a part of integrative most cancers therapy to assist sufferers deal with negative effects of chemotherapy and different most cancers remedies.

Study suggests pathways to alleviating inflammation in disorders such as sepsis, arthritis

More data:
Neuron, Liu et al.: “Somatotopic Organization and Intensity Dependence in Driving Distinct NPY-Expressing Sympathetic Pathways by Electroacupuncture” www.cell.com/neuron/fulltext/S0896-6273(20)30532-8 , DOI: 10.1016/j.neuron.2020.07.015

Evidence in mice that electroacupuncture reduces inflammation via specific neural pathways (2020, August 12)
retrieved 12 August 2020
from https://medicalxpress.com/information/2020-08-evidence-mice-electroacupuncture-inflammation-specific.html

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