Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, USA.
iPSC Core Laboratory, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
Anim Sci J. 2019 Sep;90(9):1149-1160. doi: 10.1111/asj.13272. Epub 2019 Jul 19.
Mechanisms that direct reprogramming of differentiated somatic cells to induced pluripotent stem cells (iPSCs), albeit incomplete in understanding, are highly conserved across all mammalian species studied. Equally, proof of principle that iPSCs can be derived from domestic cattle has been reported in several publications. In our efforts to derive and study bovine iPSCs, we encountered inadequacy of methods to generate, sustain, and characterize these cells. Our results suggest that iPSC protocols optimized for mouse and human somatic cells do not effectively translate to bovine somatic cells, which show some refractoriness to reprogramming that also affects sustenance. Moreover, methods that enhance reprogramming efficiency in mouse and human cells had no effect on improving bovine cell reprogramming. Although use of retroviral vectors coding for bovine OCT4, SOX2, KLF4, cMYC, and NANOG appeared to produce consistent iPSC-like cells from both fibroblasts and cells from the Wharton's jelly, these colonies could not be sustained. Use of bovine genes could successfully reprogram both mouse and human cells. These findings indicated either incomplete reprogramming and/or discordant/inadequate culture conditions for bovine pluripotent stem cells. Therefore, additional studies that advance core knowledge of bovine pluripotency are necessary before any anticipated iPSC-driven bovine technologies can be realized.
尽管人们对指导分化体细胞重编程为诱导多能干细胞（iPSCs）的机制的理解还不完全，但在所有研究过的哺乳动物物种中，这些机制都高度保守。同样，已经有几篇论文报道了从家畜牛中获得 iPSC 的原理验证。在我们努力获得和研究牛 iPSC 的过程中，我们遇到了生成、维持和表征这些细胞的方法不足的问题。我们的结果表明，针对小鼠和人体细胞优化的 iPSC 方案并不能有效地转化为牛体细胞，牛体细胞对重编程表现出一定的抗性，这也影响了维持。此外，在提高小鼠和人细胞的重编程效率的方法对改善牛细胞的重编程没有效果。虽然使用编码牛 OCT4、SOX2、KLF4、cMYC 和 NANOG 的逆转录病毒载体似乎可以从成纤维细胞和 Wharton's 胶细胞中产生一致的 iPSC 样细胞，但这些集落无法维持。使用牛基因可以成功地重编程小鼠和人细胞。这些发现表明，牛多能性干细胞的重编程不完全，或者培养条件不一致/不足。因此，在任何预期的 iPSC 驱动的牛技术实现之前，有必要进行更多的研究，以推进对牛多能性的核心知识。
