Zhao Y, Xu J, Wei J, Li J, Cai J, Miao G
The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, China.
Transplant Proc. 2010 Dec;42(10):4638-42. doi: 10.1016/j.transproceed.2010.09.154.
Islet transplantation is a promising treatment to cure diabetes, but is associated with a high rate of early graft failure. The isolation process leads to the loss of the surrounding extracellular matrix, resulting in eventual islet disintegration and apoptosis. The purpose of this study was to determine the effects on the viability of isolated islets of embedding islets in reconstituted basement membrane extract (BME), which is similar to the normal peri-islet BM composition in vivo.
Isolated mouse islets were embedded in BME gel for 24 or 48 hours. Expression of caspase-3, α3, and α5, focal adhesion kinase (FAK), phosphor-FAK, and pancreatic duodenal homeobox factor (PDX)-1 were detected with Western immunoblotting.
Impaired aggregation of single islet cells could only be observed in non-BME medium. Islets embedded in BME gel were partially protected from anoikis showed decreased caspase-3 compared with non-BME islets. We also observed an increase of α3 integrin, FAK protein level, and FAK activity. Furthermore, expression of PDX-1 was preserved at 48 hours, suggesting a positive contribution of BME to β-cell activity.
These results indicated that embedding islets in BME can upregulate α3 integrin, which may result in preservation of viability and function of isolated islets.
胰岛移植是治疗糖尿病的一种有前景的方法，但早期移植物失败率较高。分离过程会导致周围细胞外基质的丢失，最终导致胰岛解体和凋亡。本研究的目的是确定将胰岛嵌入重组基底膜提取物（BME）中对分离胰岛活力的影响，BME与体内正常胰岛周围的基底膜成分相似。
将分离的小鼠胰岛嵌入BME凝胶中24或48小时。通过蛋白质免疫印迹法检测半胱天冬酶-3、α3和α5、粘着斑激酶（FAK）、磷酸化FAK和胰腺十二指肠同源盒因子（PDX）-1的表达。
仅在非BME培养基中观察到单个胰岛细胞聚集受损。与非BME胰岛相比，嵌入BME凝胶中的胰岛部分免受失巢凋亡，半胱天冬酶-3减少。我们还观察到α3整合素、FAK蛋白水平和FAK活性增加。此外，PDX-1的表达在48小时时得以保留，表明BME对β细胞活性有积极作用。
这些结果表明，将胰岛嵌入BME中可上调α3整合素，这可能导致分离胰岛的活力和功能得以保留。
