Chan Gabriel H H, Fiscus Ronald R
Department of Physiology, Faculty of Medicine, Epithelial Cell Biology Research Center, and The Center for Gerontology and Geriatrics, The Chinese University of Hong Kong, Room 507, BMSB, Shatin, New Territories, Hong Kong, China.
Exp Gerontol. 2004 Mar;39(3):387-94. doi: 10.1016/j.exger.2004.01.002.
Nitric oxide (NO) is produced at high levels by inducible nitric oxide synthase (iNOS) during inflammation and other pathological conditions, contributing to development of cardiovascular diseases. The present study determined if aging affects the ability of interleukin-1beta (IL-1beta), a pro-inflammatory cytokine, to induce increased NO production (assessed by Griess reaction) and iNOS mRNA levels (assessed by RT-PCR/agarose gel electrophoresis) in vascular smooth muscle cells (VSMCs) from young (3-month-old) and elderly (20-22-month-old) rats. The VSMCs cells were used only in early passages (passages 0 and 1) to avoid phenotypic modulation. To uncover subtle differences in basal iNOS mRNA levels in VSMCs of young and elderly rats, RT-PCR products were also analyzed by a new ultrasensitive technique using capillary electrophoresis with laser-induced fluorescence detector (CE-LIF). IL-1beta (5 ng/ml) significantly (P < 0.05) increased NO production 3.7-fold in elderly female VSMCs and 6.7-fold in elderly male VSMCs, but had no detectable effect in young female and male VSMCs. Basal iNOS mRNA levels (assessed by RT-PCR/CE-LIF) were dramatically higher in VSMCs of elderly male rats compared to young ones. In general, VSMCs of elderly rats showed much greater sensitively to iNOS-inducing actions of IL-1beta. These data give new insight into effects of aging on iNOS expression in VSMCs, showing dramatic increases in both basal and stimulated iNOS mRNA levels, which may contribute to the development of vascular diseases in the elderly.
在炎症和其他病理状态下，诱导型一氧化氮合酶（iNOS）会大量产生一氧化氮（NO），这会促使心血管疾病的发展。本研究旨在确定衰老是否会影响促炎细胞因子白细胞介素-1β（IL-1β）诱导年轻（3个月大）和老年（20 - 22个月大）大鼠血管平滑肌细胞（VSMC）中一氧化氮生成增加（通过格里斯反应评估）以及iNOS mRNA水平增加（通过逆转录聚合酶链反应/琼脂糖凝胶电泳评估）的能力。VSMC仅在早期传代（第0代和第1代）时使用，以避免表型调节。为了揭示年轻和老年大鼠VSMC中基础iNOS mRNA水平的细微差异，还使用带有激光诱导荧光检测器的毛细管电泳新技术（CE-LIF）对逆转录聚合酶链反应产物进行了分析。IL-1β（5 ng/ml）使老年雌性VSMC中的一氧化氮生成显著增加（P < 0.05），增加了3.7倍，在老年雄性VSMC中增加了6.7倍，但对年轻雌性和雄性VSMC没有可检测到的影响。与年轻大鼠相比，老年雄性大鼠VSMC中的基础iNOS mRNA水平（通过逆转录聚合酶链反应/CE-LIF评估）显著更高。总体而言，老年大鼠的VSMC对IL-1β诱导iNOS的作用表现出更高的敏感性。这些数据为衰老对VSMC中iNOS表达的影响提供了新的见解，表明基础和刺激后的iNOS mRNA水平均显著增加，这可能有助于老年人血管疾病的发展。
