Vitamin D and Vitamin A Receptor Expression and the Proliferative Effects of Ligand Activation of These Receptors on the Development of Pancreatic Progenitor Cells Derived from Human Fetal Pancreas
Vitamin D and Vitamin A Receptor Expression and the Proliferative Effects of Ligand Activation of These Receptors on the Development of Pancreatic Progenitor Cells Derived from Human Fetal Pancreas
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DOI：
10.1007/s12015-010-9146-1
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发表时间：
2011-03-01
影响因子：
4.8
通讯作者：
Leung, Po Sing
中科院分区：
文献类型：
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作者：
Ng, Ka Yan;Ma, Man Ting;Leung, Po Sing
胰岛细胞的生长发育受多种形态因子的调控。维生素A调节胰岛细胞的体外分化，维生素D影响β细胞的胰岛素分泌，而这两种维生素配体都是通过与类视黄醇X受体（RXR）异源二聚化作用的。然而，它们在调节胰腺发育方面的作用尚未确定。在这项研究中，从人胎儿胰腺中分离培养的人胰腺祖细胞（PPCs）被刺激分化为胰岛样细胞簇（ICCs）。采用RT-PCR、Western blotting和免疫细胞化学检测PPCs中维生素D受体（VDR）、维甲酸受体（RAR）和RXR的表达和定位。采用MTT、BrdU和ELISA法分别评价添加全反式维甲酸（atRA，维生素a的一种形式）、骨化三醇（活化维生素D）及其配体对PPC细胞活力、增殖和凋亡的影响。通过实时RT-PCR检测治疗后胰岛细胞谱系发育所必需的神经原素-3 （NGN3）的表达。结果显示，PPCs中有RAR、RXR和VDR的表达。RAR和RXR定位于细胞核，VDR定位于细胞核、细胞质和质膜。atRA和骨化三醇均能提高PPC活力和增殖；atRA还能减少PPC的凋亡。atRA和骨化三醇的共添加对细胞活力没有附加效应，但确实增加了ngn3的反应。综上所述，RAR、RXR和VDR在人胎儿PPCs中均有表达，骨化三醇、atRA或两者同时可促进PPC增殖，这一数据对阐明胰岛发育机制和临床胰岛移植具有重要价值。
The growth and development of pancreatic islet cells are regulated by various morphogens. Vitamin A modulates in vitro differentiation of islet cells and vitamin D affects beta-cell insulin secretion, while both vitamin ligands act through heterodimerization with the retinoid X receptor (RXR). However, their effects in modulating pancreatic development have not been determined. In this study, cultured human pancreatic progenitor cells (PPCs) isolated from human fetal pancreas were stimulated to differentiate into islet-like cell clusters (ICCs). RT-PCR, Western blotting and immunocytochemistry were used to examine the expression and localization of vitamin D receptor (VDR), retinoic acid receptor (RAR), and RXR in PPCs. The effects of added all-trans retinoic acid (atRA, a form of vitamin A), calcitriol (activated vitamin D) and of these ligands together on PPC cell viability, proliferation and apoptosis were assessed by MTT, BrdU and ELISA assays, respectively. Post-treatment neurogenin-3 (NGN3) expression, necessary for islet-cell lineage development, was examined by real-time RT-PCR. Results showed that RAR, RXR and VDR were expressed in PPCs. RAR and RXR were localized in nuclei, and the VDR in nuclei, cytoplasm and plasma membrane. atRA and calcitriol each increased PPC viability and proliferation; atRA additionally decreased PPC apoptosis. Co-addition of atRA and calcitriol had no additive effects on cell viability but did increase ngn3 responses. In conclusion, RAR, RXR and VDR are expressed in human fetal PPCs and PPC proliferation can be promoted by calcitriol, atRA or both together, data valuable for elucidating mechanisms underlying islet development and for developing clinical islet transplantation.