繼上期發(fā)表的利用單細胞公共數(shù)據(jù)對新冠受體ACE2的研究進展后，利用單細胞研究ACE2在不同組織器官中的分布如火如荼的展開镀脂，下面介紹最新發(fā)表的兩篇文獻牺蹄。
A novel coronavirus (2019-nCoV) was first identified in Wuhan, Hubei Province, and then spreads to the other Provinces of China. WHO decides to determine a Public Health Emergency of International Concern (PHEIC) of 2019-nCoV. 2019-nCov was reported to share the same receptor, Angiotensin-converting enzyme 2 (ACE2), with SARS-Cov. Here based on the public single-cell RNA-Seq datasets, we analyzed the ACE2 RNA expression profile in the tissues at different locations of the respiratory tract. The result indicates that the ACE2 expression appears in nasal epithelial cells. We found that the size of this population of ACE2-expressing nasal epithelial cells is comparable with the size of the population of ACE2-expression type II alveolar cells (AT2) in the Asian sample reported by Yu Zhao et al. We further detected 2019-nCoV by polymerase chain reaction (PCR) from the nasal-swab and throat-swab of seven suspected cases. We found that 2019-nCoV tends to have a higher concentration in the nasal-swab comparing to the throat-swab, which could attribute to the ACE2-expressing nasal epithelial cells. We hope this study could be informative for virus-prevention strategy development, especially the treatment of nasal mucus.
2020年2月11日浙江大學醫(yī)學院附屬第一醫(yī)院傳染病診治國家重點實驗室Zheng Min團隊在醫(yī)學預印本medRxiv發(fā)表題為Single-cell RNA expression profiling of ACE2, the putative receptor of Wuhan 2019-nCoV, in the nasal tissue的研究內(nèi)容，分析了呼吸道不同位置組織中的ACE2 RNA表達譜薄翅。結果表明ACE2在鼻上皮細胞中也表達沙兰，說明鼻腔也可能是病毒感染侵襲的重要器官。
公共數(shù)據(jù)：GSE122960
數(shù)據(jù)分析
軟件：Seurat (3.1.4)
篩選：filter out the cells 1-expressing less than 200 genes; or 2-highly expressing mitochondrial genes, in which mitochondrial genes’ reads account for more than 25% of the total reads. Filter out the genes expressing in less than 3 samples.
降維聚類：默認參數(shù)
結果分析
(1)作者對亞洲捐獻者通過鼻刷樣品翘魄、支氣管活檢樣品鼎天、鼻甲和肺組織進行單細胞RNA-Seq測序(Nature重磅綜述 |關于RNA-seq，你想知道的都在這)暑竟。作者發(fā)現(xiàn)斋射，KRT8在亞洲捐獻者的鼻刷樣品，支氣管活檢樣品但荤、鼻甲和肺組織的細胞中廣泛表達(fig 1)罗岖。將KRT8作為表面細胞的標記，并將KRT5作為基底細胞的標記腹躁。然后作者將表達ACE2桑包，KRT8，和兩者都表達的細胞分別進行統(tǒng)計（table 1）潜慎，發(fā)現(xiàn)在鼻刷和鼻甲樣品中約有3.2％和2.1％的KRT8表達細胞同時表達ACE2捡多。
(2)作者分別對7名患者通過聚合酶鏈反應（PCR）檢測其鼻和咽拭子中2019-nCoV的病毒滴度蓖康，并通過循環(huán)閾值（CT）測量。我們發(fā)現(xiàn)兩名患者（table 2中的患者W1和Z1）在其鼻拭子中檢測到了2019-nCoV垒手，但在其咽拭子中未檢測到蒜焊。在Z2患者中，他的鼻拭子證實為2019-nCoV科贬。在Z4患者中泳梆，鼻拭子和咽拭子中均檢測到2019-nCoV。但是榜掌，CT值比較結果表明鼻拭子中的病毒滴度高于喉嚨拭子优妙。
In December 2019 and January 2020, novel coronavirus (2019-nCoV) - infected pneumonia (NCIP) occurred in Wuhan, and has already posed a serious threat to public health. ACE2 (Angiotensin Converting Enzyme 2) has been shown to be one of the major receptors that mediate the entry of 2019-nCoV into human cells, which also happens in severe acute respiratory syndrome coronavirus (SARS). Several researches have indicated that some patients have abnormal renal function or even kidney damage in addition to injury in respiratory system, and the related mechanism is unknown. This arouses our interest in whether coronavirus infection will affect the urinary and male reproductive systems. Here in this study, we used the online datasets to analyze ACE2 expression in different human organs. The results indicate that ACE2 highly expresses in renal tubular cells, Leydig cells and cells in seminiferous ducts in testis. Therefore, virus might directly bind to such ACE2 positive cells and damage the kidney and testicular tissue of patients. Our results indicate that renal function evaluation and special care should be performed in 2019-nCoV patients during clinical work, because of the kidney damage caused by virus and antiviral drugs with certain renal toxicity. In addition, due to the potential pathogenicity of the virus to testicular tissues, clinicians should pay attention to the risk of testicular lesions in patients during hospitalization and later clinical follow-up, especially the assessment and appropriate intervention in young patients’ fertility.
2020年2月13日，南京醫(yī)科大學附屬蘇州醫(yī)院王建清研究組在預印本網(wǎng)站medRxiv上發(fā)表題為“ACE2 Expression in Kidney and Testis May Cause Kidney and TestisDamage After 2019-nCoV Infection”的研究內(nèi)容憎账，提示新冠病毒感染可能造成腎臟和睪丸損傷套硼。
公共數(shù)據(jù) ：GSE131685 ，GSE107585
結果分析：
（1）作者首先發(fā)現(xiàn)在部分患者中出現(xiàn)明顯的腎功能異常胞皱。作者利用公共數(shù)據(jù)集 CCLE 和 GTEx探索了ACE2在泌尿系統(tǒng)中的表達水平邪意，發(fā)現(xiàn)腎細胞中ACE2 mRNA表達水平相對較高（圖1）。
圖一
（2）為了進一步確定腎細胞中ACE2的蛋白表達水平反砌，作者利用Human Protein Atlas及免疫組織化學（IHC）發(fā)現(xiàn)雾鬼，盡管mRNA表達水平不是很高，但腎臟中ACE2蛋白的表達水平明顯更高宴树，尤其是在腎小管細胞中（圖2）策菜。
圖二
作者還發(fā)現(xiàn)ACE2在睪丸細胞中表達非常高。睪丸中ACE2的蛋白質(zhì)和mRNA表達幾乎是體內(nèi)最高的酒贬。此外又憨，生精細胞和間質(zhì)細胞均顯示出高ACE2表達水平。
這些結果表明睪丸細胞是2019-nCoV的潛在靶標同衣。
(3)為了進一步評估ACE2的細胞類型特異性表達并確認腎臟中ACE2的表達水平竟块，我們從GEO（GEO131685）數(shù)據(jù)集下載了人腎臟單細胞RNA測序的基因表達數(shù)據(jù)。作者根據(jù)原始文獻中的marker進行細胞分群單細胞分群后耐齐，怎么找到Marker基因定義每一類群浪秘？（圖3A），并在腎小管細胞中發(fā)現(xiàn)了特定的ACE2表達 埠况。相反耸携，在免疫細胞和腎小球上皮細胞中未觀察到ACE2表達（圖3B）。
圖三
大總結
結合上期發(fā)表的幾篇單細胞文獻辕翰，現(xiàn)在已經(jīng)揭示了許多組織中ACE2的表達夺衍，包括：
少量的肺部AT2細胞；
鼻腔中散在表達喜命；
氣管中散在表達沟沙；
在吸收性腸上皮中高表達河劝；
少量膽管細胞中表達；
在口腔粘膜細胞中表達矛紫；
在腎小管細胞中表達赎瞎；
睪丸生精細胞和間質(zhì)細胞中表達；
我想再重復一下我上一期推送的觀點：表達ACE2就一定容易感染嗎颊咬？前幾天有篇文章報出來新冠病毒與受體結合的能力是SARS的10-20倍务甥，也說明了該次病毒侵襲之快的一個重要原因（先前文獻說親和力低于SARS）。但是否表達ACE2就一定會感染喳篇，這個問題其實是有待商榷的敞临，只能說通過受體進行感染，但病毒生命周期中所需要的細胞元件在宿主細胞是否都存在也是需要考量的麸澜；我曾經(jīng)看過一篇文獻挺尿，題目我給忘啦（耍流氓，哈哈哈）炊邦，里面比較經(jīng)典的實驗就是從中華菊頭蝠中分離出的SARS-like冠狀病毒票髓，用來侵襲其他物種蝙蝠時，即使大量表達ACE2也不能在該bat中增殖感染铣耘，說明可不是僅僅看看ACE2的有無和親和力與否那樣簡單。
