Neuroprotective effects of PPAR-γ agonists against oxidative insults in HT-22 cells
Neuroprotective effects of PPAR-γ agonists against oxidative insults in HT-22 cells
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DOI：
10.1016/s0014-2999(03)01867-3
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发表时间：
2003-07-04
影响因子：
5
通讯作者：
Simpkins, JW
中科院分区：
文献类型：
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作者：
Aoun, P;Watson, DG;Simpkins, JW
过氧化物酶体增殖物激活受体（PPARs）参与调节许多代谢和炎症过程。本研究探讨PPAR配体在保护神经元培养物免受毒性损伤中的作用。为此，我们使用WY 14643[4-氯-6(2,3-木基dino)-2-嘧啶基硫代乙酸]作为pparα激动剂，L-165041和L-783483作为pparβ配体，15-脱氧- δ (12,14) -PGJ2 （15d-PGJ2）、曲格列酮和西格列酮作为pparγ激动剂。实验使用永生化小鼠海马细胞系HT-22和人神经母细胞瘤细胞系SK-N-SH进行。采用钙黄蛋白乙酰氧基甲基（AM）法测定细胞抗谷氨酸、过氧化氢（H2O2）和血清剥夺损伤的活力。在测试的化合物中，只有15d-PGJ2和曲格列酮在HT-22细胞中对谷氨酸和H2O2的损伤表现出剂量依赖性的神经保护作用。没有一种PPAR激动剂对SK-N-SH细胞具有保护作用。15d-PGJ2至少需要4-6小时的预孵育才能达到显著的神经保护作用。另一方面，曲格列酮即使与谷氨酸同时施用，或谷氨酸损伤后8小时仍具有保护作用。为了研究PPARgamma是否介导了神经保护作用，我们首先通过Western blotting检测HT-22和SK-N-SH细胞表达PPARgamma。然而，由于两个原因，这些化合物的神经保护作用不太可能通过PPARgamma介导：(1)不同浓度的另一种PPARgamma激动剂（西格列酮）不具有神经保护作用；(2) PPAR本身对DNA的亲和力较低，高亲和力结合需要与9-顺式维甲酸受体RXR异源二聚化；9-顺式维甲酸与15d-PGJ2联合使用不会改变后者的神经保护作用。我们的研究结果表明15d-PGJ2和曲格列酮的神经保护作用可能不依赖于PPARgamma。(C) 2003 Elsevier B.V.版权所有
Peroxisome proliferator-activated receptors (PPARs) are involved in regulating many metabolic and inflammatory processes. The present study explores the role of PPAR ligands in protecting neuronal cultures from toxic insults. For that purpose, we used WY 14643 [4-chloro-6(2,3-xylidino)-2-pyrimidinylthio acetic acid] as a PPARalpha agonist, L-165041 and L-783483 as PPARbeta ligands, and 15-deoxy-Delta(12,14) -PGJ2 (15d-PGJ2), troglitazone, and ciglitazone for PPARgamma. Experiments were performed using HT-22, an immortalized mouse hippocampal cell line, and SK-N-SH, a human neuroblastoma cell line. Cell viability against glutamate, hydrogen peroxide (H2O2), and serum deprivation insults was determined using a calcein acetoxymethyl (AM) assay. Of the compounds tested, only 15d-PGJ2 and troglitazone showed a dose-dependent neuroprotection from glutamate and H2O2 insults in HT-22 cells. None of the PPAR agonists was protective in SK-N-SH cells. A minimum of 4-6 h preincubation with 15d-PGJ2 was required to achieve significant neuroprotection. On the other hand, troglitazone was protective even when administered simultaneously with glutamate, or for up to 8 h postglutamate insult. To investigate whether the neuroprotective effects are mediated through PPARgamma, we first determined through Western blotting that HT-22 and SK-N-SH cells express PPARgamma. However, the neuroprotective effects of those compounds are unlikely to be mediated through the PPARgamma for two reasons: (1) various concentrations of another PPARgamma agonist (ciglitazone) were not neuroprotective; (2) by itself, PPAR exhibits a low affinity for DNA, and high-affinity binding requires heterodimerization with RXR, the 9-cis-retinoic acid receptor; administering 9-cis-retinoic acid in conjunction with 15d-PGJ2 did not alter the neuroprotective effects of the latter. Our results demonstrate neuroprotective effects of 15d-PGJ2 and troglitazone that are likely independent of PPARgamma. (C) 2003 Elsevier B.V. All rights reserved.