Islet xenotransplantation is a promising treatment for type I diabetes. Numerous studies of islet xenotransplantation have used pig-to-nonhuman primate transplantation models. Some studies reported long-term survival and successful function of porcine islets in diabetic monkeys. Genetic engineering techniques may improve the survival and function of porcine islets. A recent study reported the generation of transgenic pigs expressing human insulin rather than porcine insulin by changing one amino acid at the end of the β-chain in insulin. However, C-peptide from pigs still existed. In this study, we generated transgenic pigs expressing human proinsulin to express human insulin and C-peptide using fibroblasts from proinsulin knockout pigs as donor cells for somatic cell nuclear transfer. Eleven live piglets were delivered from three surrogates and characterized to confirm the genotype and phenotype of the generated piglets. Genotype analysis of the generated piglets showed that five of the eleven piglets contained the human proinsulin gene. Insulin expression was confirmed in the serum and pancreas in two of the five piglets. C-peptide derived from human proinsulin was also confirmed by liquid chromatography tandem mass spectrometry. Non-fasting blood glucose level was measured to verify the function of the insulin derived from the human proinsulin. Two piglets expressing insulin showed normal glucose levels similar to that in the wild-type control. In conclusion, human insulin- and C-peptide-expressing pigs without porcine insulin and C-peptide were successfully established. These pigs can be used as a source of islets for islet xenotransplantation.

中文翻译：

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表达人胰岛素和C肽作为异种移植胰岛的来源的转基因猪的生产。

胰岛异种移植是治疗I型糖尿病的有前途的治疗方法。胰岛异种移植的许多研究都使用了猪到非人类的灵长类动物移植模型。一些研究报道了糖尿病猴中猪胰岛的长期存活和成功功能。基因工程技术可以改善猪胰岛的存活和功能。最近的一项研究报道了通过改变胰岛素β链末端的一个氨基酸来表达人胰岛素而不是猪胰岛素的转基因猪。但是，来自猪的C-肽仍然存在。在这项研究中，我们使用来自胰岛素原剔除猪的成纤维细胞作为体细胞核移植的供体细胞，产生了表达人胰岛素原的转基因猪，以表达人胰岛素和C肽。从三个替代物中交付了11只活仔猪，并对其特性进行了鉴定，以确认所产生仔猪的基因型和表型。对产生的仔猪的基因型分析表明，十一只仔猪中有五个含有人胰岛素原基因。在五个小猪中的两个中，在血清和胰腺中证实了胰岛素表达。还通过液相色谱串联质谱法确认了源自人胰岛素原的C-肽。测量非空腹血糖水平以验证源自人胰岛素原的胰岛素的功能。两只表达胰岛素的小猪显示出与野生型对照相似的正常葡萄糖水平。总之，成功建立了不含猪胰岛素和C肽的表达人胰岛素和C肽的猪。