Hanson Amanda M, Gambill Jessica, Phomakay Venusa, Staten C Tyler, Kelley Melissa D
Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, United States of America.
College of Medicine, University of Arkansas Medical Sciences, Little Rock, Arkansas, United States of America.
PLoS One. 2014 Mar 26;9(3):e93005. doi: 10.1371/journal.pone.0093005. eCollection 2014.
Retinoids are established pleiotropic regulators of both adaptive and innate immune responses. Recently, troglitazone, a PPAR gamma agonist, has been demonstrated to have anti-inflammatory effects. Separately, retinoids and troglitazone are implicated in immune related processes; however, their combinatory role in cellular adhesion and proliferation has not been well established. In this study, the effect of 9-cis-retinoic acid (9-cis-RA) and troglitazone on K562 cellular adhesion and proliferation was investigated. Troglitazone exposure decreased K562 cellular adhesion to RGD containing extracellular matrix proteins fibronectin, FN-120, and vitronectin in a concentration and time-dependent manner. In the presence of troglitazone, 9-cis-retinoic acid restores cellular adhesion to levels comparable to vehicle treatment alone on fibronectin, FN-120, and vitronectin substrates within 72 hours. Due to the prominent role of integrins in attachment to extracellular matrix proteins, we evaluated the level of integrin α5 subunit expression. Troglitazone treatment results in decrease in α5 subunit expression on the cell surface. In the presence of both agonists, cell surface α5 subunit expression was restored to levels comparable to vehicle treatment alone. Additionally, troglitazone and 9-cis-RA mediated cell adhesion was decreased in the presence of a function blocking integrin alpha 5 inhibitor. Further, through retinoid metabolic profiling and HPLC analysis, our study demonstrates that troglitazone augments retinoid availability in K562 cells. Finally, we demonstrate that troglitazone and 9-cis-retinoic acid synergistically dampen cellular proliferation in K562 cells. Our study is the first to report that the combination of troglitazone and 9-cis-retinoic acid restores cellular adhesion, alters retinoid availability, impacts integrin expression, and dampens cellular proliferation in K562 cells.
维甲酸是公认的适应性免疫反应和先天性免疫反应的多效性调节剂。最近，吡格列酮（一种PPARγ激动剂）已被证明具有抗炎作用。另外，维甲酸和吡格列酮都与免疫相关过程有关；然而，它们在细胞黏附和增殖中的联合作用尚未完全明确。在本研究中，研究了9-顺式维甲酸（9-cis-RA）和吡格列酮对K562细胞黏附和增殖的影响。吡格列酮处理以浓度和时间依赖性方式降低K562细胞与含RGD的细胞外基质蛋白纤连蛋白、FN-120和玻连蛋白的黏附。在吡格列酮存在的情况下，9-顺式维甲酸在72小时内将细胞黏附恢复到与单独使用溶剂处理相当的水平，作用于纤连蛋白、FN-120和玻连蛋白底物。由于整合素在附着于细胞外基质蛋白中起重要作用，我们评估了整合素α5亚基的表达水平。吡格列酮处理导致细胞表面α5亚基表达降低。在两种激动剂同时存在的情况下，细胞表面α5亚基表达恢复到与单独使用溶剂处理相当的水平。此外，在存在功能阻断性整合素α5抑制剂的情况下，吡格列酮和9-顺式维甲酸介导的细胞黏附降低。此外，通过维甲酸代谢谱分析和高效液相色谱分析，我们的研究表明吡格列酮可提高K562细胞中维甲酸的可用性。最后，我们证明吡格列酮和9-顺式维甲酸协同抑制K562细胞的增殖。我们的研究首次报道吡格列酮和9-顺式维甲酸的组合可恢复细胞黏附、改变维甲酸可用性、影响整合素表达并抑制K562细胞的增殖。
