Chowdhury T T, Bader D L, Lee D A
Medical Engineering Division and IRC in Biomedical Materials, Department of Engineering, Queen Mary, University of London, Mile End Road, London, UK.
Osteoarthritis Cartilage. 2003 Sep;11(9):688-96. doi: 10.1016/s1063-4584(03)00149-3.
To examine the effect of IL-1 beta-induced *NO and PGE(2)release by stimulated superficial and deep chondrocyte/agarose constructs subjected to mechanical compression.
Chondrocyte sub-populations were seeded separately in agarose constructs and cultured unstrained, within a 24-well tissue culture plate, for 48 h in medium supplemented with IL-1 beta and/or L-N-(1-iminoethyl)-ornithine (L-NIO). In a separate experiment, superficial and deep cell containing constructs were subjected to 15% dynamic compressive strain at 1 Hz, for 48 h, in the presence or absence of IL-1 beta and/or L-NIO. Nitrite was measured using the Griess assay, PGE(2)release was determined using an EIA kit and [3H]-thymidine and 35SO(4)incorporation were assessed by TCA and alcian blue precipitation, respectively.
The current data reveal that IL-1 beta significantly enhanced *NO and PGE(2)release for superficial chondrocytes, an effect reversed with L-NIO. *NO and PGE(2)levels did not significantly change by deep cells in the presence of IL-1 beta and/or L-NIO. For both cell sub-populations, IL-1 beta inhibited cell proliferation whereas proteoglycan synthesis was not affected. Dynamic compression inhibited the release of *NO and PGE(2)in the presence and absence of IL-1 beta, for cells from both sub-populations. L-NIO reduced *NO and enhanced PGE(2)release for superficial zone chondrocytes, an effect not observed for deep cells in response to dynamic compression. The magnitude of stimulation of [3H]-thymidine incorporation was similar for both cell sub-populations and was not influenced by L-NIO, indicating an z.rad;NO-independent pathway. The dynamic compression-induced stimulation of 35SO(4)incorporation was enhanced with L-NIO for IL-1 beta-stimulated deep cells, indicating an *NO-dependent pathway.
The present findings suggest that dynamic compression inhibits *NO and PGE(2)release in IL-1 beta-stimulated superficial cells via distinct pathways, a significant finding that may contribute to the development of intervention strategies for the treatment of inflammatory joint disorders.
研究白细胞介素-1β（IL-1β）诱导的一氧化氮（*NO）和前列腺素E2（PGE2）释放对受机械压缩刺激的浅层和深层软骨细胞/琼脂糖构建体的影响。
将软骨细胞亚群分别接种到琼脂糖构建体中，在补充有IL-1β和/或L-N-（1-亚氨基乙基）-鸟氨酸（L-NIO）的培养基中，于24孔组织培养板中无应变培养48小时。在另一个实验中，在有或无IL-1β和/或L-NIO的情况下，对含有浅层和深层细胞的构建体施加1Hz的15%动态压缩应变，持续48小时。使用格里斯试剂测定亚硝酸盐，使用酶免疫分析试剂盒测定PGE2释放，分别通过三氯乙酸沉淀和阿尔新蓝沉淀评估[3H]-胸腺嘧啶核苷掺入和35SO4掺入。
目前的数据显示，IL-1β显著增强浅层软骨细胞的NO和PGE2释放，L-NIO可逆转该效应。在有IL-1β和/或L-NIO的情况下，深层细胞的NO和PGE(2)水平没有显著变化。对于这两个细胞亚群，IL-1β抑制细胞增殖，而蛋白聚糖合成不受影响。在有和无IL-1β的情况下，动态压缩均抑制了这两个亚群细胞的NO和PGE2释放。L-NIO降低了浅层软骨细胞的NO并增强了PGE2释放，对于深层细胞，在动态压缩时未观察到这种效应。两个细胞亚群的[3H]-胸腺嘧啶核苷掺入刺激程度相似，且不受L-NIO影响，表明存在一条不依赖NO的途径。对于IL-1β刺激的深层细胞，L-NIO增强了动态压缩诱导的35SO4掺入刺激，表明存在一条依赖NO的途径。
目前的研究结果表明，动态压缩通过不同途径抑制IL-1β刺激的浅层细胞中的*NO和PGE2释放，这一重要发现可能有助于开发治疗炎症性关节疾病的干预策略。
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