干细胞：治疗勃起功能障碍的新玩家

Stem cells： novel players in the treatment of erectile dysfunction

干细胞因其具有自我更新和定向分化的能力而得名，因此，它们赋予了再生医学巨大的潜力。从历史渊源看，干细胞曾被列为胚胎干细胞（ESCs）或成体干细胞（ASCs）。过去人们认为，只有胚胎干细胞具有分化成任何类型细胞的能力，而ASCs只有生成具有一个给定胚层细胞的能力。然而，最近许多研究表明ASCs具有分化成超出他们组织起源的细胞类型的能力。本综述总结了当代关于干细胞的可用性和分化的结果，尤其是关于这些细胞在动物模型和人体研究中诊断和治疗勃起功能障碍（ED）方面的潜力。我们在PubMed上进行文章搜索，包括干细胞的定义、定位和循环，以及干细胞在ED诊断和治疗方面的应用。目前，干细胞疗法作为未来潜在的治疗ED的方法这一概念已经被很多有利的证据支持。迄今为止，各种干细胞，包括骨髓间充质干细胞，脂肪源性干细胞和肌源性干细胞，已在ED治疗的神经，血管，内皮或平滑肌再生方面的动物模型中进行了研究。此外，几种成体干细胞的亚型分布于阴茎，循环内源性干细胞可以用来预测ED以及与ED有关的心血管疾病的治疗结果。

Stem cells are defined by their capacity for both self-renewal and directed differentiation; thus, they represent great promise for regenerative medicine. Historically, stem cells have been categorized as either embryonic stem cells （ESCs） or adult stem cells （ASCs）. It was previously believed that only ESCs hold the ability to differentiate into any cell type, whereas ASCs have the capacity to give rise only to cells of a given germ layer. More recently, however, numerous studies demonstrated the ability of ASCs to differentiate into cell types beyond their tissue origin. The aim of this review was to summarize contemporary evidence regarding stem cell availability, differentiation, and more specifically, the potential of these cells in the diagnosis and treatment of erectile dysfunction （ED） in both animal models and human research. We performed a search on PubMed for articles related to definition, iocalisation and circulation of stem cells as well as the application of stem cells in both diagnosis and treatment of ED. Strong evidence supports the concept that stem cell therapy is potentially the next therapeutic approach for ED. To date, a large spectrum of stem cells, including bone marrow mesenchymal stem cells, adipose tissue-derived stem cells and muscle-derived stem cells, have been investigated for neural, vascular, endothelial or smooth muscle regeneration in animal models for ED. In addition, several subtypes of ASCs are localized in the penis, and circulating endogenous stem cells can be employed to predict the outcome of ED and ED-related cardiovascular diseases.