SARS-CoV-2、肠道菌群失调和腹泻之间的关系:探索 ACE2/mTOR/自噬途径。
Premises among SARS-CoV-2, dysbiosis and diarrhea: Walking through the ACE2/mTOR/autophagy route.
机构信息
The Northest Biotechnology Network, Federal University of Piauí, Teresina, Piauí, Brazil.
Biotechnology and Biodiversity Center Research, BIOTEC, Federal University of the Parnaíba Delta, Parnaíba, Piauí, Brazil.
出版信息
Med Hypotheses. 2020 Nov;144:110243. doi: 10.1016/j.mehy.2020.110243. Epub 2020 Sep 2.
Recently, a new coronavirus (SARS-CoV-2) was discovered in China. Due to its high level of contagion, it has already reached most countries, quickly becoming a pandemic. Although the most common symptoms are related to breathing problems, SARS-CoV-2 infections also affect the gastrointestinal tract culminating in inflammation and diarrhea. However, the mechanisms related to these enteric manifestations are still not well understood. Evidence shows that the SARS-CoV-2 binds to the angiotensin-converting enzyme receptor 2 (ACE2) in host cells as a viral invasion mechanism and can infect the lungs and the gut. Other viruses have already been linked to intestinal symptoms through binding to ACE2. In turn, this medical hypothesis article conjectures that the ACE2 downregulation caused by the SARS-CoV-2 internalization could lead to decreased activation of the mechanistic target of mTOR with increased autophagy and lead to intestinal dysbiosis, resulting in diarrhea. Besides that, dysbiosis can directly affect the respiratory system through the lungs. Although there are clues to other viruses that modulate the ACE2/gut/lungs axis, including the participation of autophagy and dysbiosis in the development of gastrointestinal symptoms, there is still no evidence of the ACE2/mTOR/autophagy pathway in SARS-CoV-2 infections. Thus, we propose that the new coronavirus causes a change in the intestinal microbiota, which culminates in a diarrheal process through the ACE2/mTOR/autophagy pathway into enterocytes. Our assumption is supported by premises that unregulated intestinal microbiota increases the susceptibility to other diseases and extra-intestinal manifestations, which can even cause remote damage in lungs. These putative connections lead us to suggest and encourage future studies aiming at assessing the aforementioned hypothesis and regulating dysbiosis caused by SARS-CoV-2 infection, in order to confirm the decrease in lung injuries and the improvement in the prognosis of the disease.
最近,在中国发现了一种新型冠状病毒(SARS-CoV-2)。由于其高传染性,它已经传播到了大多数国家,迅速成为一种大流行疾病。尽管最常见的症状与呼吸问题有关,但 SARS-CoV-2 感染也会影响胃肠道,最终导致炎症和腹泻。然而,与这些肠道表现相关的机制仍未得到很好的理解。有证据表明,SARS-CoV-2 通过作为病毒入侵机制与宿主细胞中的血管紧张素转换酶受体 2(ACE2)结合,并能感染肺部和肠道。其他病毒已经通过与 ACE2 结合与肠道症状有关。反过来,这篇医学假设文章推测,SARS-CoV-2 内化引起的 ACE2 下调可能导致机械性靶标 mTOR 的激活减少,自噬增加,导致肠道菌群失调,从而导致腹泻。除此之外,菌群失调还可以通过肺部直接影响呼吸系统。虽然有其他病毒调节 ACE2/肠道/肺部轴的线索,包括自噬和菌群失调参与胃肠道症状的发展,但在 SARS-CoV-2 感染中仍然没有 ACE2/mTOR/自噬途径的证据。因此,我们提出新型冠状病毒导致肠道微生物群发生变化,通过 ACE2/mTOR/自噬途径进入肠细胞,最终导致腹泻过程。我们的假设是基于这样的前提,即不受调节的肠道微生物群增加了对其他疾病和肠外表现的易感性,甚至可能导致肺部的远程损伤。这些假设的联系使我们建议并鼓励未来的研究,旨在评估上述假设,并调节由 SARS-CoV-2 感染引起的菌群失调,以确认肺部损伤的减少和疾病预后的改善。