再生醫(yī)學,，或者說利用專門培養(yǎng)的組織和細胞來治療損傷和疾病,，在治療包括心臟、胰腺和軟骨在內的多種器官疾病方面取得成功,。然而,，利用再生技術來治療角膜內皮(corneal endothelium)---角膜內表面的單細胞層---疾病的療效性并不是太好。如今,，一個研究團隊開發(fā)出一種方法來加強移植的角膜內皮細胞(corneal endothelial cells,， CECs)的附著，從而成功地開展角膜移植來修復病理性的角膜功能障礙。相關研究結果于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,、日本同志社大學生命與醫(yī)學科學學院生物醫(yī)學工程部門研究員Noriko Koizumi博士解釋道，“角膜內皮功能障礙是嚴重性視力受損的主要原因,，這是因為角膜內皮細胞起著維持角膜透明的作用,。當將體外培養(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,，導致它們的附著性較差,。以前的研究證實Rho相關激酶(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)一起進行移植,，能夠成功地讓角膜恢復透明。”
研究人員以兔細胞作為研究對象,，在實驗室培養(yǎng)兔角膜內皮細胞(CECs),，并將它們注射到角膜內皮受損的兔眼的前房(anterior chamber)?；诮悄绕すδ艿幕謴颓闆r,，他們發(fā)現(xiàn)當把體外培養(yǎng)的兔CECs與Y-27632一起進行注射時，兔角膜在注射后48小時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,，則導致角膜模糊不清和嚴重性腫脹,。研究人員沒有觀察到與細胞注射療法相關的并發(fā)癥。當CECs與Y-27632一起注射而重建的角膜內皮表現(xiàn)出正常的六邊形細胞形狀,。
鑒于兔CECs在體內高度增殖,，研究人員利用猴角膜內皮細胞(CECs)開展另一輪實驗，而且猴CECs更加類似于人CECs,。在這些靈長類動物中進行CECs移植也能夠成功地讓角膜長期保持透明,，同時產生單層六邊形細胞，這就提示著利用ROCK抑制劑改變細胞附著性能可能是一種有效地治療人角膜內皮疾病的方法,。
盡管人們已經開發(fā)出外科技術來替換受損的角膜內皮,，但是這些操作程序在技術上比較困難，而且因捐獻的角膜比較短缺而面臨挑戰(zhàn),。Koizumi博士作出結論,，“這種將細胞療法與ROCK抑制物結合在一起的新策略最終可能在再生醫(yī)學上提供一種新的治療方法，不僅可以用來治療角膜內皮功能障礙,，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.
