Genetic analysis of four novel peroxisome proliferator activated receptor-γ splice variants in monkey macrophages
Genetic analysis of four novel peroxisome proliferator activated receptor-γ splice variants in monkey macrophages
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DOI：
10.1016/s0006-291x(02)00138-9
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发表时间：
2002-04-26
影响因子：
3.1
通讯作者：
Medh, JD
中科院分区：
文献类型：
--
作者：
Zhou, JM;Wilson, KM;Medh, JD
过氧化物酶体增殖物激活受体- γ (ppar - γ)在动脉粥样硬化病变中大量表达，并与动脉粥样硬化发生有关。存在PPAR-gamma1、PPAR-gamma2三个剪接变异体。PPAR-gamma3已经建立。利用食蟹猴单核细胞来源的巨噬细胞，我们在这里证明了两个新的ppar - γ外显子，外显子C和外显子d的鉴定，它们与已经建立的外显子a1， A2和B在5'末端区域拼接在一起，产生了四个新的ppar - γ亚型。PPAR-gamma4, -gamma5, -gamma6。和-gamma7。PPAR-gamma4和-gamma5仅在巨噬细胞中检测到，而gamma6和gamma7在巨噬细胞和脂肪组织中均有表达。在猴子的肌肉、肾脏和脾脏中均未检测到这些新的异构体。我们在人类基因组数据库中发现了与外显子C和D相同的序列。这些以及迄今已知的所有ppar - γ外显子都是由位于人类3号染色体10498 K至10384 K区域的单个基因编码的。我们利用表达载体pPICZB克隆并表达了PPAR-gamma1、PPAR-gamma4和PPAR-gamma5蛋白。像预期的那样。所有重组蛋白分子量约为50 kDa。我们还研究了高脂肪饮食对猴子巨噬细胞ppar - γ表达水平的影响。RT-PCR显示，与维持正常饮食的猴子相比，脂肪喂养的猴子（n = 7）巨噬细胞中ppar - γ和ABCA1 mRNA的总水平显著增加（n = 2）。然而。这些新的异构体似乎都不是由脂肪喂养引起的。我们使用四环素反应性表达载体在CHO细胞中获得了PPAR-gamma4和-gamma5的适度表达。在这些细胞中。PPAR-gamma5的表达抑制ABCA1的表达，而-gamma4的表达不调节脂蛋白脂肪酶的表达。我们的研究结果表明，单个ppar - γ亚型可能负责独特的组织特异性生物学效应，PPAR-gamma4和-gamma5可能调节巨噬细胞功能和动脉粥样硬化。(C) 2002 Elsevier Science （USA）。版权所有。
Peroxisome proliferator activated receptor-gamma (PPAR-gamma) is abundantly expressed in atherosclerotic lesions and is implicated in atherogenesis. The existence of three splice variants, PPAR-gamma1, PPAR-gamma2. and PPAR-gamma3 has been established. Using monocyte-derived macrophages from cynomolgus monkeys, we demonstrate here the identification of two new, PPAR-gamma exons, exon C and exon D. which splice together with already established exons A 1, A2, and B in the 5' terminal region to generate four novel PPAR-gamma subtypes. PPAR-gamma4, -gamma5, -gamma6. and -gamma7. PPAR-gamma4 and -gamma5 Aere detected only in macrophages whereas gamma6 and gamma7 were expressed both in macrophages and adipose tissues. None of these novel isoforms were detected in Muscle, kidney, and spleen from monkeys. We found sequences identical to exons C and D in the human genome database. These and all PPAR-gamma exons known to date are encoded by a single gene, located from region 10498 K to 10384 K on human chromosome 3. We cloned and expressed PPAR-gamma1, PPAR-gamma4, and PPAR-gamma5 proteins in beast using the expression vector pPICZB. As expected. all recombinant proteins showed a molecular Weight of approximately 50 kDa. We also investigated the effect of a high-fat diet on the level of macrophage PPAR-gamma expression in monkeys. RT-PCR showed a significant increase in total PPAR-gamma and ABCA1 mRNA levels in macrophages of fat-fed monkeys (n = 7) compared to those maintained on a normal diet (it 2). However. none of the novel isoforms seemed to be induced by fat-feeding. We used tetracycline-responsive expression vectors to obtain moderate expression of PPAR-gamma4 and -gamma5 in CHO cells. In these cells. expression of PPAR-gamma5 but not -gamma4 repressed the expression of ABCA1 Neither isoform modulated the expression of lipoprotein lipase. Our results suggest that individual PPAR-gamma isoforms may be responsible for unique tissue-specific biological effects and that PPAR-gamma4 and -gamma5 may modulate macrophage function and atherogenesis. (C) 2002 Elsevier Science (USA). All rights reserved.