Recombinant human prolactin promotes human beta cell survival via inhibition of extrinsic and intrinsic apoptosis pathways
Recombinant human prolactin promotes human beta cell survival via inhibition of extrinsic and intrinsic apoptosis pathways
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DOI：
10.1007/s00125-011-2102-z
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发表时间：
2011-06-01
期刊：
影响因子：
8.2
通讯作者：
Labriola, L.
中科院分区：
文献类型：
--
作者：
Terra, L. F.;Garay-Malpartida, M. H.;Labriola, L.
胰岛移植是治疗1型糖尿病的一种有前途的替代疗法。然而，由于器官捐献者短缺，这受到了限制。我们实验室的先前结果已经证明了重组人催乳素（rhPRL）处理对β细胞培养物的有益作用。因此，我们研究了rhPRL作用在人β细胞存活中的作用，重点是参与这一过程的分子机制。在不存在或存在rhPRL的情况下对胰岛培养物进行预处理，然后进行血清饥饿或细胞因子处理。用纽波特绿色标记β细胞，并使用流式细胞术分析评估细胞凋亡。采用RT-PCR和Western blot检测BCL 2基因家族成员的表达水平。通过荧光测定法评价了Caspase-8、-9和-3活性以及一氧化氮的产生。在两种细胞死亡诱导条件下，rhPRL的存在均显着降低了凋亡β细胞的比例。本研究还证实了催乳素对人β细胞凋亡的保护作用可能与增加BCL 2/BAX比值以及抑制caspase-8、-9和-3有关。结果还表明，细胞存活的改善可能至少部分涉及抑制由BCL 2基因家族成员控制的细胞死亡途径。这些发现对于改进胰岛分离程序和临床胰岛移植具有重要意义。
Transplantation of pancreatic islets constitutes a promising alternative treatment for type 1 diabetes. However, it is limited by the shortage of organ donors. Previous results from our laboratory have demonstrated beneficial effects of recombinant human prolactin (rhPRL) treatment on beta cell cultures. We therefore investigated the role of rhPRL action in human beta cell survival, focusing on the molecular mechanisms involved in this process.Human pancreatic islets were isolated using an automated method. Islet cultures were pre-treated in the absence or presence of rhPRL and then subjected to serum starvation or cytokine treatment. Beta cells were labelled with Newport green and apoptosis was evaluated using flow cytometry analysis. Levels of BCL2 gene family members were studied by quantitative RT-PCR and western blot. Caspase-8, -9 and -3 activity, as well as nitric oxide production, were evaluated by fluorimetric assays.The proportion of apoptotic beta cells was significantly lowered in the presence of rhPRL under both cell death-induced conditions. We also demonstrated that cytoprotection may involve an increase of BCL2/BAX ratio, as well as inhibition of caspase-8, -9 and -3.Our study provides relevant evidence for a protective effect of lactogens on human beta cell apoptosis. The results also suggest that the improvement of cell survival may involve, at least in part, inhibition of cell death pathways controlled by the BCL2 gene family members. These findings are highly relevant for improvement of the islet isolation procedure and for clinical islet transplantation.