日本科學(xué)家發(fā)現(xiàn)造成口臭(halitosis)的氣味難聞的化合物非常適合用于收集從人牙髓(dental pulp)中提取的干細(xì)胞。2012年2月27日,，這些研究結(jié)果發(fā)表在Journal of Breath Research期刊上,。
在這項(xiàng)研究中，研究人員證實(shí)硫化氫(hydrogen sulphide, H2S)能夠增加成體干細(xì)胞分化為肝細(xì)胞的能力,，從而提高成體干細(xì)胞作為未來肝細(xì)胞治療的一種可靠來源的名聲,。
這是第一次發(fā)現(xiàn)肝細(xì)胞能夠產(chǎn)自人牙髓，而且更讓人印象深刻的是,，它們能夠大量生產(chǎn)同時(shí)保持高純度,。
該研究論文通訊作者Ken Yaegaki博士說，“高純度意味著干細(xì)胞分化產(chǎn)生的組成其他組織的‘錯(cuò)誤細(xì)胞’比較少,，而且干細(xì)胞本身也很少有殘留,。再者，這些事實(shí)提示著接受肝細(xì)胞移植的病人幾乎不可能產(chǎn)生畸胎瘤(teratoma)或癌癥,，而當(dāng)用骨髓干細(xì)胞進(jìn)行移植時(shí)則往往會(huì)產(chǎn)生這種情況,。”
干細(xì)胞的令人注目的轉(zhuǎn)化能力已成為全世界研究小組關(guān)注的重要焦點(diǎn)，同時(shí)也讓科學(xué)家期待利用它們治療包括帕金森疾病和阿爾茨海默疾病(Alzheimer's disease)在內(nèi)的很多疾病,。
在這項(xiàng)研究中,，Ken Yaegaki博士和來自日本齒科大學(xué)的同事們利用來自牙髓---牙齒的中央部分，由結(jié)締組織和細(xì)胞組成---的干細(xì)胞進(jìn)行研究,，其中這些干細(xì)胞是從正在接受常規(guī)拔牙的牙科患者的牙齒中獲得的,。
一旦干細(xì)胞被制備得足夠多，它們就被分成兩個(gè)批次(測(cè)試組和對(duì)照組)并且測(cè)試組細(xì)胞在H2S培養(yǎng)箱中孵育,。在3天,、6天和9天之后，它們分別被收集下來進(jìn)行分析以便觀察這些細(xì)胞是否成功地轉(zhuǎn)化為肝細(xì)胞,。
為了測(cè)試這些干細(xì)胞在H2S影響下是否能夠成功地分化為肝細(xì)胞，研究人員進(jìn)行一系列測(cè)試來研究干細(xì)胞分化產(chǎn)生的細(xì)胞是否擁有肝細(xì)胞的典型特征,。除了在顯微鏡下的物理觀察之外,，研究人員研究了它們儲(chǔ)存糖原的能力，并記錄了細(xì)胞中尿素含量,。
Yaegaki博士繼續(xù)說道,，“直到現(xiàn)在，沒有人發(fā)明出再生大量肝細(xì)胞用于人類移植的實(shí)驗(yàn)方法,。相比于利用胎牛血清生產(chǎn)肝細(xì)胞的傳統(tǒng)方法,，我們的方法產(chǎn)率高,，而且更為重要的是，它也更安全,。”
硫化氫(H2S)有著特有的臭雞蛋氣味,，能夠在全身組織中產(chǎn)生。盡管它所起的確切功能仍不清楚,，但是研究人員相信它在很多生理過程和疾病狀態(tài)中發(fā)揮著關(guān)鍵性作用,。(生物谷：towersimper編譯)
doi:10.1088/1752-7155/6/1/017103
PMC:
PMID:
Hydrogen sulfide increases hepatic differentiation in tooth-pulp stem cells
Nikolay Ishkitiev, Bogdan Calenic, Izumi Aoyama, Hisataka Ii, Ken Yaegaki and Toshio Imai
The toxicity of hydrogen sulfide (H2S), an oral malodorous compound, is well reported. We have recently established an experimental model of hepatic differentiation from human tooth-pulp stem cells (HTPC) using serum-free medium. The objective of the present study is to determine the effect of H2S on hepatic differentiation. The CD117 positive cell fraction was obtained from deciduous HTPC using magnetic cell sorting. After 3–4 passages, cells were grown in Dulbecco's modified Eagle's medium supplemented with insulin-transferrin-selenium-x (ITS-x), embryotrophic factor (ETF) and hepatocyte growth factor (HGF) for hepatic commitment (five days). For hepatic differentiation the cells were cultured in Iscove's modified Dulbecco's medium supplemented with ITS-x, ETF, oncostatin, HGF and dexamethasone for 15 days in air containing 5% CO2, with or without H2S at 0.05 ng ml−1. Cells were assayed for the expression of hepatic markers α-fetoprotein, albumin or carbamoyl phosphate synthetase, and urea concentrations and glycogen synthesis were also determined. The panel of hepatic markers was expressed more in the test groups exposed to H2S than in the control groups. Urea and glycogen production were also increased, especially glycogen which was approximately five times greater compared to the control (p < 0.01). We concluded that H2S at physiological concentrations increased the ability of HTPC to undergo hepatogenic differentiation.
