腸道中存在著“第二大腦”

帕金森氏癥的發(fā)現(xiàn)暗示了腸道中存在著“第二大腦”

A growing body of evidence is forging a stronger and stronger connection between the onset of Parkinson’s disease and the gut. Scientists at Karolinska Institutet in Sweden and the University of North Carolina at Chapel Hill have thrown further weight behind this theory, with an investigation of cellular behavior in the nervous system of the digestive system revealing possible tell-tale signs at the earliest stages of the disease.

越來越多的證據(jù)表明，帕金森病的發(fā)病與腸道之間的聯(lián)系越來越緊密。瑞典卡羅琳斯卡研究所和北卡羅來納大學(xué)教堂山分校的科學(xué)家們進(jìn)一步強(qiáng)調(diào)了這一理論，他們對(duì)消化系統(tǒng)神經(jīng)系統(tǒng)的細(xì)胞行為進(jìn)行了研究，揭示了疾病早期可能的信號(hào)。

The notion that Parkinson’s disease could get its start in the gut has been around for some time, but in recent years we are seeing some compelling research that suggests our bellies may well play an important role in its onset. The disease is characterized by the cell death of neurons that secrete dopamine in the brain, which drives the motor impairments and other common symptoms of the illness.

關(guān)于帕金森氏病可以在腸道中開始的觀念已經(jīng)存在了一段時(shí)間，但是近年來，我們看到一些引人注目的研究表明，我們的腹部很可能在其發(fā)病中起重要作用。該疾病的特征是大腦中分泌多巴胺的神經(jīng)元細(xì)胞死亡，這會(huì)導(dǎo)致運(yùn)動(dòng)障礙和該疾病的其他常見癥狀。

What causes the demise of these neurons is not known for certain, but a leading hypothesis is that it is caused by aggregations of misfolded proteins known as Lewy bodies. An animal study last year produced the best evidence to date that these toxic protein clumps first form in the gut and move upward to the brain via the vagus nerve.

導(dǎo)致這些神經(jīng)元死亡的原因尚不確定，但一個(gè)主要的假設(shè)是，它是由錯(cuò)誤折疊的蛋白質(zhì)(稱為路易小體)的聚集引起的。去年的一項(xiàng)動(dòng)物研究提供了迄今為止最好的證據(jù)，表明這些有毒蛋白團(tuán)塊首先在腸道中形成，然后通過迷走神經(jīng)向上移動(dòng)到大腦。

This new research hints at the role the enteric nervous system, as the regulator of digestive system, could play in these processes. Made up of a hundreds of millions of neurons, the body’s largest collection outside the brain, the enteric nervous system can operate independently of the central nervous system and for this reason is sometimes referred to as “the second brain.”

這項(xiàng)新的研究表明，腸神經(jīng)系統(tǒng)作為消化系統(tǒng)的調(diào)節(jié)者，可能在這些過程中發(fā)揮作用。腸道神經(jīng)系統(tǒng)由數(shù)億個(gè)神經(jīng)元組成，是人體大腦以外最大的集合，它可以獨(dú)立于中樞神經(jīng)系統(tǒng)運(yùn)作，因此有時(shí)被稱為“ 第二大腦”。

The authors of the new research studied gene expression in mice in combination with human genetics to systematically identify cell types that underly certain brain disorders. They then analyzed brain tissue taken from both healthy subjects and sufferers of Parkinson’s, taken at different stages of the disease. This revealed alterations in enteric neurons, “even at the earliest stages of disease progression,” the scientists write.

這項(xiàng)新研究的作者結(jié)合人類遺傳學(xué)研究了小鼠中的基因表達(dá)，以系統(tǒng)地識(shí)別某些腦部疾病的細(xì)胞類型。然后，他們分析了從健康受試者和帕金森氏癥患者的腦組織中提取的，在疾病的不同階段采集的組織。科學(xué)家寫道，這揭示了腸道神經(jīng)元的改變，甚至在疾病發(fā)展的最早階段。

"As expected, we found that dopaminergic neurons were associated with Parkinson's disease,” says senior author Patrick Sullivan. “More surprisingly, we found that enteric neurons also seem to play an important role in the disorder, supporting the hypothesis that Parkinson's disease starts in the gut.”

“正如預(yù)期的那樣，我們發(fā)現(xiàn)多巴胺能神經(jīng)元與帕金森氏癥有關(guān)，”資深作者帕特里克·沙利文說。“更令人驚訝的是，我們發(fā)現(xiàn)腸內(nèi)神經(jīng)元似乎在這種疾病中也起著重要作用，支持帕金森氏病始于腸道的假設(shè)。”

The team’s research also produced another useful insight. By looking at these brain tissue samples taken at different points in disease progression, they found that important support cells in the brain called oligodendrocytes were impacted early on, even before the loss of the dopamine-producing neurons.

該小組的研究也產(chǎn)生了另一個(gè)有用的見解。通過觀察這些在疾病進(jìn)展的不同階段采集的腦組織樣本，他們發(fā)現(xiàn)大腦中重要的支持細(xì)胞少突膠質(zhì)細(xì)胞在早期受到影響，甚至在產(chǎn)生多巴胺的神經(jīng)元喪失之前。

“These results suggest that oligodendrocyte could be an attractive target for therapeutic interventions as they appear to be affected before dopaminergic neurons,” says the Karolinska Institutet’s Julien Bryois, senior author of the study.

該研究的高級(jí)作者卡羅林斯卡研究所的朱利安·布賴伊斯(Julien Bryois)說：“這些結(jié)果表明，少突膠質(zhì)細(xì)胞可能是治療干預(yù)的一個(gè)有吸引力的靶標(biāo)，因?yàn)樗鼈兯坪踉诙喟桶纺苌窠?jīng)元之前就受到了影響。”

The research was published in the journal Nature Genetics.

這項(xiàng)研究發(fā)表在《自然遺傳學(xué)》雜志上。