Understanding the Molecular Mechanisms of Early Postnatal Development of Pig Islets

在啮齿类动物中，很少有人研究胰岛在出生后的发育，到目前为止还没有研究过猪生后胰岛的发育，特别是细胞黏附分子和钙粘附素在这一过程中的作用。因此，我的NSERC项目的新发现将为我们更好地了解参与胰岛结构形成和维护的分子以及出生后胰岛的正常功能。此外，猪胰岛的血管内皮细胞成分还知之甚少。一段时间以来，成年猪的胰岛与新生猪的胰岛相比，由于其脆弱的性质，很难在培养中分离和保持，这使得新生猪的胰岛成为一个有吸引力的移植胰岛来源。此外，一段时间以来，人们已经知道新生的猪胰岛有能力成长为成熟的胰岛。然而，新生猪胰岛成熟的过程仍有待阐明。我怀疑钙粘附素可能在一定程度上解释了我们观察到的新生猪胰岛和成年猪胰岛的差异。自从我开始研究新生的猪胰岛以来，该领域大多数研究的重点一直是开发如何防止它们被排斥的策略。这些策略涉及猪胰岛捐赠者的基因工程等，它们在包括非人类灵长类动物在内的大型动物模型中存活和发挥作用的能力已被证明是成功的。然而，这些接受者受到严重的免疫抑制，这些方案毒性很大，不适用于人类患者。随着世界范围内越来越多的转基因猪被创造出来作为胰岛移植的来源，猪胰岛的基础生物学还没有得到深入的研究。因此，我们对组织的了解一直是有限的，我们希望将其用作解决人类胰岛移植短缺的可能方案。我认为，了解猪胰岛的基本生物学是成功将猪胰岛移植移植到临床的基础。我还相信，我们对用于移植的组织了解得越多，我们就越能在不使用免疫抑制药物的情况下成功移植组织。这些药物不仅对组织本身有害，而且对胰岛移植接受者造成感染和癌症发展的主要风险。

Very few studies in rodents have investigated the development of islets after birth and none so far has examined the development of pig islets during postnatal period in particular, the role of cell adhesion molecules, cadherins in this process. Thus, novel findings from my NSERC program will provide a better understanding on the molecules involve in the formation and maintenance of islet architecture as well as normal function of islets after birth. In addition, the vascular endothelial components of pig islets are poorly understood. It has been known for some time that islets from adult pigs are difficult to isolate and maintain in culture due to their fragile nature compared to islets from newborn pigs, which make the latter an attractive source of islets for transplantation. In addition, it has been known for some time that newborn pig islets have the capacity to grow into mature islets. However, the processes involved in the maturation of newborn pig islets remain to be elucidated. I suspect that cadherins may explain in part the differences we observed between newborn and adult pig islets. Since I started working on newborn pig islets the focus of majority of studies in the field has been on developing strategies on how to prevent their rejection. These strategies involved the genetic engineering of pig islet donors among others and their ability to survive and function in large animal models including non-human primates has been proven to be successful. However, these recipients were heavily immunosuppressed and these regimens are very toxic and are not applicable to human patients. As more and more genetically engineered pigs being created worldwide as source of islets for transplantation, the basic biology of pig islets has not been intensively studied. Thus, our understanding of the tissue we hope to use as a possible solution to the shortage of human islets for transplantation has been limited. I believe that understanding the basic biology of pig islets is fundamental in the successful translation of pig islet transplantation to the clinic. I also believe that the more we know about the tissue we are using for transplantation the more we will be able to successfully transplant the tissue without using immunosuppressive drugs. These drugs are harmful to the tissue itself as well as they pose major risk of infection and development of cancer in islet transplant recipients.