Mun Gyeong In, Lee Seung Jin, An Sang Mi, Kim In Kyeom, Boo Yong Chool
Department of Molecular Medicine and Cell and Matrix Research Institute, BK21 Medical Education Program for Human Resources, Republic of Korea.
Free Radic Biol Med. 2009 Aug 1;47(3):291-9. doi: 10.1016/j.freeradbiomed.2009.04.032. Epub 2009 May 3.
Laminar shear stress (LSS) caused by blood flow is known to regulate endothelial function and to contribute to vascular health. By way of contrast, endothelial cell senescence seems to increase the incidence of vascular disorders. In an attempt to identify genes associated with vascular health/disease states, this study assessed the differential gene expression of young and senescent human umbilical vein endothelial cells (HUVECs) under static and LSS conditions. Replicative cell senescence was induced by continuous subculture in vitro, and LSS was provided using a cone-and-plate device. Young (p4) and senescent (p18) cells were subjected to LSS at 12 dyn.cm(-2) or maintained under static conditions for 24 h. Total mRNA was subjected to cDNA microarray analysis using the Affymetrix GeneChip. Welch t test at a significance level of p < 0.05 provided 961 "LSS-responsive" genes, whose expression was altered by LSS in both young and senescent cells, and 529 "senescence-responsive" genes differentially expressed in young vs senescent cells under both static and LSS conditions. The LSS-responsive and senescence-responsive gene groups included 74 genes held in common; these may prove useful for the study of cellular responses commonly affected by LSS and senescence. Among them, 20 genes whose expression was increased by LSS and simultaneously decreased by cellular senescence are suggested as potential vascular health markers in the sense that LSS is antiatherogenic, whereas senescence is proatherogenic. These genes included argininosuccinate synthetase 1, which was determined to be critical for both basal and LSS-induced NO production in young HUVECs. Furthermore, its diminished expression, and not that of nitric oxide synthase 3, was implicated in the insufficient NO production exhibited by senescent HUVECs under LSS conditions. The genes identified in this study are expected to facilitate improvements in our current level of understanding regarding endothelial physiology in association with age-associated vascular disease.
已知血流引起的层流切应力（LSS）可调节内皮功能并有助于血管健康。相比之下，内皮细胞衰老似乎会增加血管疾病的发生率。为了确定与血管健康/疾病状态相关的基因，本研究评估了年轻和衰老的人脐静脉内皮细胞（HUVECs）在静态和LSS条件下的差异基因表达。通过体外连续传代诱导复制性细胞衰老，并使用锥板装置提供LSS。将年轻（第4代）和衰老（第18代）细胞置于12达因·厘米-2的LSS条件下或在静态条件下维持24小时。使用Affymetrix基因芯片对总mRNA进行cDNA微阵列分析。在显著性水平p < 0.05下进行的韦尔奇t检验确定了961个“LSS反应性”基因，其表达在年轻和衰老细胞中均因LSS而改变，以及529个“衰老反应性”基因，在静态和LSS条件下，年轻与衰老细胞中差异表达。LSS反应性和衰老反应性基因组共有74个共同基因；这些基因可能对研究通常受LSS和衰老影响的细胞反应有用。其中，有20个基因的表达因LSS而增加，同时因细胞衰老而降低，从LSS具有抗动脉粥样硬化作用而衰老具有促动脉粥样硬化作用的意义上来说，这些基因被认为是潜在的血管健康标志物。这些基因包括精氨琥珀酸合成酶1，已确定其对年轻HUVECs的基础和LSS诱导的一氧化氮（NO）产生都至关重要。此外，衰老的HUVECs在LSS条件下表现出的NO产生不足与精氨琥珀酸合成酶1表达的降低有关，而非一氧化氮合酶3表达的降低。预计本研究中鉴定的基因将有助于提高我们目前对与年龄相关的血管疾病相关的内皮生理学的理解水平。
