再生醫(yī)學(xué)，或者說利用專門培養(yǎng)的組織和細(xì)胞來治療損傷和疾病，在治療包括心臟、胰腺和軟骨在內(nèi)的多種器官疾病方面取得成功,。然而,，利用再生技術(shù)來治療角膜內(nèi)皮(corneal endothelium)---角膜內(nèi)表面的單細(xì)胞層---疾病的療效性并不是太好。如今,，一個(gè)研究團(tuán)隊(duì)開發(fā)出一種方法來加強(qiáng)移植的角膜內(nèi)皮細(xì)胞(corneal endothelial cells,， CECs)的附著，從而成功地開展角膜移植來修復(fù)病理性的角膜功能障礙,。相關(guān)研究結(jié)果于2012年6月13日在線發(fā)表在American Journal of Pathology期刊上,。
論文通訊作者、日本同志社大學(xué)生命與醫(yī)學(xué)科學(xué)學(xué)院生物醫(yī)學(xué)工程部門研究員Noriko Koizumi博士解釋道,，“角膜內(nèi)皮功能障礙是嚴(yán)重性視力受損的主要原因,，這是因?yàn)榻悄?nèi)皮細(xì)胞起著維持角膜透明的作用。當(dāng)將體外培養(yǎng)的CECs注入到角膜組織后,，注入的CECs因房水流動(aqueous humor flow)而被沖洗走,，導(dǎo)致它們的附著性較差。以前的研究證實(shí)Rho相關(guān)激酶(Rho-associated kinase,， ROCK)信號干擾這種附著,。我們發(fā)現(xiàn)將體外培養(yǎng)的CECs與抑制ROCK的低分子量化合物(ROCK抑制物Y-27632)一起進(jìn)行移植,，能夠成功地讓角膜恢復(fù)透明,。”
研究人員以兔細(xì)胞作為研究對象，在實(shí)驗(yàn)室培養(yǎng)兔角膜內(nèi)皮細(xì)胞(CECs),，并將它們注射到角膜內(nèi)皮受損的兔眼的前房(anterior chamber),。基于角膜內(nèi)皮功能的恢復(fù)情況,，他們發(fā)現(xiàn)當(dāng)把體外培養(yǎng)的兔CECs與Y-27632一起進(jìn)行注射時(shí),，兔角膜在注射后48小時(shí)再次獲得完全的透明度。相比之下,，如果只注射兔CECs而不注射Y-27632,，則導(dǎo)致角膜模糊不清和嚴(yán)重性腫脹。研究人員沒有觀察到與細(xì)胞注射療法相關(guān)的并發(fā)癥,。當(dāng)CECs與Y-27632一起注射而重建的角膜內(nèi)皮表現(xiàn)出正常的六邊形細(xì)胞形狀,。
鑒于兔CECs在體內(nèi)高度增殖，研究人員利用猴角膜內(nèi)皮細(xì)胞(CECs)開展另一輪實(shí)驗(yàn),，而且猴CECs更加類似于人CECs,。在這些靈長類動物中進(jìn)行CECs移植也能夠成功地讓角膜長期保持透明，同時(shí)產(chǎn)生單層六邊形細(xì)胞,，這就提示著利用ROCK抑制劑改變細(xì)胞附著性能可能是一種有效地治療人角膜內(nèi)皮疾病的方法,。
盡管人們已經(jīng)開發(fā)出外科技術(shù)來替換受損的角膜內(nèi)皮，但是這些操作程序在技術(shù)上比較困難,，而且因捐獻(xiàn)的角膜比較短缺而面臨挑戰(zhàn),。Koizumi博士作出結(jié)論,，“這種將細(xì)胞療法與ROCK抑制物結(jié)合在一起的新策略最終可能在再生醫(yī)學(xué)上提供一種新的治療方法，不僅可以用來治療角膜內(nèi)皮功能障礙,，也可用來治療各種病理性疾病,。”(生物谷：Bioon.com)
doi:10.1016/j.ajpath.2012.03.033
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ROCK Inhibitor Converts Corneal Endothelial Cells into a Phenotype Capable of Regenerating In Vivo Endothelial Tissue
Naoki Okumura, Noriko Koizumi, Morio Ueno, Yuji Sakamoto, Hiroaki Takahashi, Hideaki Tsuchiya, Junji Hamuro, Shigeru Kinoshita
Corneal endothelial dysfunction accompanied by visual disturbance is a primary indication for corneal transplantation. We previously reported that the adhesion of corneal endothelial cells (CECs) to a substrate was enhanced by the selective ROCK inhibitor Y-27632. It is hypothesized that the inhibition of ROCK signaling may manipulate cell adhesion properties, thus enabling the transplantation of cultivated CECs as a form of regenerative medicine. In the present study, using a rabbit corneal endothelial dysfunction model, the transplantation of CECs in combination with Y-27632 successfully achieved the recovery of corneal transparency. Complications related to cell injection therapy, such as the abnormal deposition of the injected cells as well as the elevation of intraocular pressure, were not observed. Reconstructed corneal endothelium with Y-27632 exhibited a monolayer hexagonal cell shape with a normal expression of function-related markers, such as ZO-1, and Na+/K+-ATPase, whereas reconstruction without Y-27632 exhibited a stratified fibroblastic phenotype without the expression of markers. Moreover, transplantation of CECs in primates in the presence of the ROCK inhibitor also achieved the recovery of long-term corneal transparency with a monolayer hexagonal cell phenotype at a high cell density. Taken together, these results suggest that the selective ROCK inhibitor Y-27632 enables cultivated CEC-based therapy and that the modulation of Rho-ROCK signaling activity serves to enhance cell engraftment for cell-based regenerative medicine.
