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每30分钟就有一名糖尿病患者因组织溃疡恶化为坏死而失去下肢功能，这是糖尿病典型的并发症。因此，找到一种恰当的治疗方法以阻止该并发症的发展是研究此病理过程的科学家们优先考虑的问题。布里斯托大学的Paolo Madeddu是欧洲心血管与基因联合网（EVGN）的科学家，他与意大利米兰the Istituto Besta的同事和法国波尔多INSERM U441的EVGN科学家们共同合作，设计了一个基于血管祖细胞（VPC）治疗的实验模型。在实验室里，该模型被证明对缺血性糖尿病溃疡有效。

今天（2006年12月13日）该研究在图卢兹举行的EVGN年会（12月11日－14日）上公布。由于研究数据还是初步数据，因此将该结果应用于人类还需要很长时间。然而，这些令人鼓舞的结果促使科学家们开始了一系列新的实验，旨在研究VPC分泌的能愈合糖尿病溃疡的物质特性。

糖尿病是一个社会性疾病，全世界有数百万人罹患此病。糖尿病引起的缺血性溃疡导致深层组织破坏，常造成肌肉和骨骼功能下降。很常见的是，溃疡并发感染会使抵抗力已经低下的糖尿病患者病情更加恶化。

科学家们开始对干细胞治疗糖尿病溃疡感兴趣已经有几年时间。然而，在该研究中Paolo Madeddu和他的同事采用的是血管祖细胞。EVGN的科学家解释说，“这些细胞还没有被完全特性化，但是，我们发现血管祖细胞在血管周围显示出了相当强的再生能力。此外，血管祖细胞还能阻碍细胞自杀或凋亡。”

该研究的一个主要目的是制作糖尿病模型，以便科学家们检验VPC的再生能力。Madeddu说，“我们借用小鼠模型，形成类似于人类的溃疡。建立一个亚组给予VPC，一周之后，我们检查VPC对溃疡的全部影响情况。结果发现，治疗组与未治疗组相比，溃疡深度变浅面积变小了，周围有大量的新生毛细血管包围，这充分说明再生过程正在进行。

另外一项研究进一步证实了这种治疗方法的有效性。科学家注意到，VPCs能够刺激细胞增生，抑制细胞凋亡。凋亡是坏死组织激活的一种保护性机制，当组织不能修复损伤时就会发生坏死。将VPC置入损害处，它的作用就像是“条件培养基”，细胞在培养基中生长。这个培养基包含了一种或更多种未识别的因素能刺激内皮细胞增生。识别这些刺激内皮细胞增生的因素对将来的研究至关重要。上述研究以及未来的其他研究结果能够为基于祖细胞的靶向治疗，或者说是基于祖细胞分泌的有治疗作用物质的治疗奠定基础。

欧洲心血管和基因联合网（EVGN）是欧委会在第六框架计划 “生命科学、基因及有关健康的生物技术”下建立的第一个有关血管疾病的显效网络。此次EVGN年会由法国施维雅制药公司提供的无限制教育基金赞助。

Human Vascular Progenitor Cells Used To Treat Diabetes Ulcers

Main Category: Diabetes News
Article Date: 01 Jan 2007 - 0:00 PST

Every 30 minutes a diabetic patient loses the use of his bottom limb due to the ulceration of tissues that degenerates into a necrosis, which is a typical side effect of this disease. For this reason, finding a proper treatment able to arrest this complication is among the priorities of the scientists who study this pathology. Paolo Madeddu, scientist of the European Vascular Genomics Network (EVGN) from the University of Bristol, in a collaborative effort with colleagues from the Istituto Besta in Milano and EVGN scientists from INSERM U441 in Bordeaux, devised an experimental model based on the administration of Vascular Progenitor Cells (VPC). In the laboratory settings the model proved to be effective on ischemic diabetic ulcers.

The research was presented today, December 13th 2006, at the Annual EVGN Conference which is taking place in Toulouse (Dec. 11-14). As they are still preliminary data, the applications of these results to man are still far in the future. However, these extremely encouraging results prompted the scientist to start a whole set of new experiments aimed at the characterization of the compounds secreted by the VPCs, which are responsible for the healing properties on diabetic ulcers.

Diabetes is a social disease that affects several million people worldwide. The ischemic ulcers it causes are lesions that damage the deepest layers of tissues, markedly reducing muscles and bones functions. Quite often, they generate infections that aggravate the conditions of already compromised patients.

It’s been a few years since scientists developed an interest in the therapeutic potential of stem cells for the treatment of diabetic ulcers. In this study, however, Paolo Madeddu and colleagues used so-called Vascular Progenitor Cells. “These cells have not been fully characterized yet” explained the EVGN scientist “but we know that they display a considerable regenerative potential in the vascular environment. Besides, they are able to counteract the cellular suicide, or apoptosis”.

A major objective of the study was the creation of a diabetic model that allowed the scientists to test the regenerative capacities of VPCs. “We employed a murine model that can develop ulcers similar to those observed in humans” Madeddu said. “Then we administered a specific subpopulation of VPCs and, a week after the treatment, we checked what was the overall effect on the ulcers. We observed that the treated lesions had become thinner and smaller compared to the untreated ones, and that they were surrounded by a number of newborn capillaries, indicating that a regeneration process was ongoing”.

A further confirmation that the treatment was efficacious came from another observation: scientists noticed that VPCs stimulated cellular proliferation and inhibited cellular apoptosis, a defensive mechanism which is active also in necrotic tissues that the organism resorts to when it is unable to heal damages. Effective as well was the “conditioned medium”, that is the medium where cells were cultured, after its administration on the lesions. “The medium - underlined Madeddu - contains one or more unidentified factors that stimulate endothelial cell proliferation. Its identification will be critical for the future of this research. These and other future results could set the ground for a targeted therapy, based on the administration of progenitor cells, or in alternative, on the administration of the therapeutic compounds that they secrete.

The European Vascular Genomics Network (EVGN) is the first Network of Excellence on cardiovascular disease funded by the European Commission under the 6th Framework Programme "Life sciences, genomics and biotechnology for health" (Contract Number: LSHM-CT-2003-503254).

The Conference is supported by an unrestricted educational grant from Laboratoires SERVIER.

http://www.medicalnewstoday.com/medicalnews.php?newsid=59712

编辑：蓝色幻想