Agarwal S, Long P, Gassner R, Piesco N P, Buckley M J
University of Pittsburgh, Pennsylvania, USA.
Arthritis Rheum. 2001 Mar;44(3):608-17. doi: 10.1002/1529-0131(200103)44:3<608::AID-ANR109>3.0.CO;2-2.
To discern the effects of continuous passive motion on inflamed temporomandibular joints (TMJ).
The effects of continuous passive motion on TMJ were simulated by exposing primary cultures of rabbit TMJ fibrochondrocyte monolayers to cyclic tensile strain (CTS) in the presence of recombinant human interleukin-1beta (rHuIL-1beta) in vitro. The messenger RNA (mRNA) induction of rHuIL-1beta response elements was examined by semiquantitative reverse transcriptase-polymerase chain reaction. The synthesis of nitric oxide was examined by Griess reaction, and the synthesis of prostaglandin E2 (PGE2) was examined by radioimmunoassay. The synthesis of proteins was examined by Western blot analysis of the cell extracts, and synthesis of proteoglycans via incorporation of 35S-sodium sulfate in the culture medium.
Exposure of TMJ fibrochondrocytes to rHuIL-1beta resulted in the induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2), which were paralleled by NO and PGE2 production. Additionally, IL-1beta induced significant levels of collagenase (matrix metalloproteinase 1 [MMP-1]) within 4 hours, and this was sustained over a period of 48 hours. Concomitant application of CTS abrogated the catabolic effects of IL-1beta on TMJ chondrocytes by inhibiting iNOS, COX-2, and MMP-1 mRNA production and NO, PGE2, and MMP-1 synthesis. CTS also counteracted cartilage degradation by augmenting expression of mRNA for tissue inhibitor of metalloproteinases 2 that is inhibited by rHuIL-1beta. In parallel, CTS also counteracted rHuIL-1beta-induced suppression of proteoglycan synthesis. Nevertheless, the presence of an inflammatory signal was a prerequisite for the observed CTS actions, because fibrochondrocytes, when exposed to CTS alone, did not exhibit any of the effects described above.
CTS acts as an effective antagonist of rHuIL-1beta by potentially diminishing its catabolic actions on TMJ fibrochondrocytes. Furthermore, CTS actions appear to involve disruption/regulation of signal transduction cascade of rHuIL-1beta upstream of mRNA transcription.
探讨持续被动运动对炎症性颞下颌关节（TMJ）的影响。
在体外，将兔TMJ纤维软骨细胞单层原代培养物暴露于重组人白细胞介素-1β（rHuIL-1β）存在下的循环拉伸应变（CTS）中，以模拟持续被动运动对TMJ的影响。通过半定量逆转录聚合酶链反应检测rHuIL-1β反应元件的信使核糖核酸（mRNA）诱导情况。通过格里斯反应检测一氧化氮的合成，通过放射免疫测定法检测前列腺素E2（PGE2）的合成。通过对细胞提取物进行蛋白质印迹分析检测蛋白质的合成，并通过在培养基中掺入35S-硫酸钠检测蛋白聚糖的合成。
TMJ纤维软骨细胞暴露于rHuIL-1β导致诱导型一氧化氮合酶（iNOS）和环氧化酶2（COX-2）的诱导，同时伴有NO和PGE2的产生。此外，IL-1β在4小时内诱导出显著水平的胶原酶（基质金属蛋白酶1 [MMP-1]），并在48小时内持续存在。同时应用CTS可通过抑制iNOS、COX-2和MMP-1 mRNA的产生以及NO、PGE2和MMP-1的合成，消除IL-1β对TMJ软骨细胞的分解代谢作用。CTS还通过增加被rHuIL-1β抑制的金属蛋白酶组织抑制剂2的mRNA表达来对抗软骨降解。同时，CTS也对抗rHuIL-1β诱导的蛋白聚糖合成抑制。然而，炎症信号的存在是观察到的CTS作用的前提条件，因为纤维软骨细胞单独暴露于CTS时，未表现出上述任何效应。
CTS可能通过减少rHuIL-1β对TMJ纤维软骨细胞的分解代谢作用，而成为rHuIL-1β的有效拮抗剂。此外，CTS的作用似乎涉及在mRNA转录上游破坏/调节rHuIL-1β的信号转导级联。
