Stem Cells and Diabetes Section, Lab #12, National Center for Cell Science, Ganeshkhind Road, Pune, MH 411007, India.
Differentiation. 2009 Nov;78(4):232-40. doi: 10.1016/j.diff.2009.07.004. Epub 2009 Aug 7.
Generation of insulin-producing cells remains a major limitation for cellular replacement therapy in treatment of diabetes. To understand the potential of human umbilical cord blood (hUCB)-derived mononuclear cells (MNCs) in cell replacement therapy for diabetes, we studied MNCs isolated from 270 human umbilical cord blood samples. We characterized these by immunostaining and real-time PCR and studied their ability to differentiate into insulin-producing cells. We observe that freshly isolated MNCs as well as mesenchymal-like cells grown out by in vitro culture of isolated MNCs express key pancreatic transcription factors: pdx1, ngn3, isl1, brn4 and pax6. However, after 32-fold expansion, MNCs show decreased abundance of pdx1 and ngn3, indicating that islet/pancreatic progenitors detected in freshly isolated MNCs die or are diluted out during in vitro expansion. We therefore transplanted freshly isolated MNCs in NOD/SCID (immuno-incompetent) or FVB/NJ (immuno-competent) mice to check their ability to differentiate into insulin-producing cells. We observe that after 9 weeks of transplantation, approximately 25% grafts exhibit human insulin-producing (16% immunopositive) cells. The number and abundance of pro-insulin transcript-containing cells increased when the animals underwent partial pancreatectomy, 15 days after transplantation. Our results indicate that such hUCB-derived MNC population contains a subset of "pancreas-committed" cells that have the potential to differentiate into insulin-producing cells in vivo. Further studies in understanding the differentiation potential of this subset of pancreas-committed hUCB-derived MNCs will provide us with an autologous source of "lineage-committed" progenitors for cell replacement therapy in diabetes.
生成胰岛素分泌细胞仍然是细胞替代治疗糖尿病的主要限制。为了了解人脐血（hUCB）衍生的单核细胞（MNC）在糖尿病细胞替代治疗中的潜力，我们研究了从 270 个人脐血样本中分离出的 MNC。我们通过免疫染色和实时 PCR 对其进行了特征描述，并研究了它们分化为胰岛素分泌细胞的能力。我们观察到，新鲜分离的 MNC 以及通过分离的 MNC 体外培养生长出的间充质样细胞表达关键的胰腺转录因子：pdx1、ngn3、isl1、brn4 和 pax6。然而，在 32 倍扩增后，MNC 显示出 pdx1 和 ngn3 的丰度降低，表明在新鲜分离的 MNC 中检测到的胰岛/胰腺祖细胞在体外扩增过程中死亡或被稀释。因此，我们将新鲜分离的 MNC 移植到 NOD/SCID（免疫无能）或 FVB/NJ（免疫功能正常）小鼠中，以检查它们分化为胰岛素分泌细胞的能力。我们观察到，在移植后 9 周，大约 25%的移植物中存在人胰岛素产生（16%免疫阳性）细胞。移植后 15 天，当动物接受部分胰腺切除术时，含前胰岛素转录物的细胞数量和丰度增加。我们的结果表明，这种 hUCB 衍生的 MNC 群体包含一个“胰腺定向”细胞亚群，具有在体内分化为胰岛素分泌细胞的潜力。进一步研究了解这个“胰腺定向”hUCB 衍生 MNC 亚群的分化潜力，将为我们提供用于糖尿病细胞替代治疗的自体“谱系定向”祖细胞的来源。
