解偶联蛋白 2 调节 L 细胞中的胰高血糖素样肽-1 分泌。

Uncoupling protein 2 regulates glucagon-like peptide-1 secretion in L-cells.

机构信息

Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China.

出版信息

World J Gastroenterol. 2012 Jul 14;18(26):3451-7. doi: 10.3748/wjg.v18.i26.3451.

DOI:10.3748/wjg.v18.i26.3451

PMID:22807616

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC3396199/

Abstract

AIM

To investigate whether uncoupling protein 2 (UCP2) affects oleic acid-induced secretion of glucagon-like peptide-1 (GLP-1) in L-cells.

METHODS

mRNA and protein expression of UCP2 were analyzed in human NCI-H716 cells, which serve as a model for enteroendocrine L-cells, by quantitative reverse transcription-polymerase chain reaction and Western blotting before and after treatment with oleic acid. Localization of UCP2 and GLP-1 in NCI-H716 cells was assessed by immunofluorescence labeling. NCI-H716 cells were transiently transfected with a small interfering RNA (siRNA) that targets UCP2 (siUCP2) or with a non-specific siRNA using Lipofectamine 2000. The concentrations of bioactive GLP-1 in the medium were measured by enzyme linked immunosorbent assay.

RESULTS

Both GLP-1 and UCP2 granules were expressed mainly in the cytoplasm of NCI-H716 cells. NCI-H716 cells that secreted GLP-1 also expressed UCP2. Time-course experiments revealed that release of GLP-1 from NCI-H716 cells into the medium reached a maximum at 120 min and remained stable until at least 180 min after treatment with oleic acid (the level of GLP-1 increased about 2.3-fold as compared with the level of GLP-1 in the control cells, P < 0.05). In an experiment to determine dose dependence, stimulation of NCI-H716 cells with ≤ 8 mmol oleic acid led to a concentration-dependent release of GLP-1 into the medium; 10 mmol oleic acid diminished the release of GLP-1. Furthermore, GLP-1 secretion induced by oleic acid from NCI-H716 cells that were transfected with siUCP2 decreased to 41.8%, as compared with NCI-H716 cells that were transfected with a non-specific siRNA (P < 0.01).

CONCLUSION

UCP2 affected GLP-1 secretion induced by oleic acid. UCP2 plays an important role in L-cell secretion that is induced by free fatty acids.

摘要

目的

研究解偶联蛋白 2（UCP2）是否影响油酸诱导的 L 细胞分泌胰高血糖素样肽-1（GLP-1）。

方法

采用实时定量聚合酶链反应和 Western blot 分析油酸处理前后人 NCI-H716 细胞（一种肠内分泌 L 细胞模型）中 UCP2 的 mRNA 和蛋白表达。通过免疫荧光标记评估 NCI-H716 细胞中 UCP2 和 GLP-1 的定位。用 Lipofectamine 2000 将靶向 UCP2 的小干扰 RNA（siUCP2）或非特异性 siRNA 瞬时转染入 NCI-H716 细胞。用酶联免疫吸附试验测定培养基中生物活性 GLP-1 的浓度。

结果

GLP-1 和 UCP2 颗粒主要表达于 NCI-H716 细胞的细胞质中。分泌 GLP-1 的 NCI-H716 细胞也表达 UCP2。时程实验显示，NCI-H716 细胞向培养基中释放 GLP-1 在油酸处理 120 分钟时达到最大值，并在至少 180 分钟内保持稳定（与对照组细胞相比，GLP-1 水平增加约 2.3 倍，P<0.05）。在确定剂量依赖性的实验中，用 ≤8 mmol 油酸刺激 NCI-H716 细胞可导致 GLP-1 浓度依赖性地释放到培养基中；10 mmol 油酸则可减少 GLP-1 的释放。此外，用 siUCP2 转染的 NCI-H716 细胞由油酸诱导的 GLP-1 分泌减少至 41.8%，与用非特异性 siRNA 转染的 NCI-H716 细胞相比（P<0.01）。