Nitric oxide and G proteins mediate the response of bovine articular chondrocytes to fluid-induced shear
Nitric oxide and G proteins mediate the response of bovine articular chondrocytes to fluid-induced shear
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DOI：
10.1002/jor.1100150113
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发表时间：
1997-01-01
影响因子：
2.8
通讯作者：
Smith, RL
中科院分区：
文献类型：
--
作者：
Das, P;Schurman, DJ;Smith, RL
机械负荷改变关节软骨的代谢，可能是由于剪切应力对软骨细胞的影响。在培养的软骨细胞中，糖胺聚糖的合成增加响应于流体诱导的剪切。本研究验证了剪切应力增加软骨细胞中一氧化氮的产生，然后一氧化氮影响糖胺聚糖代谢的假设。还分析了一氧化氮合酶、G蛋白、磷脂酶C、钾通道和钙通道的抑制剂对一氧化氮释放和糖胺聚糖合成的影响。使用锥形粘度计对成年牛关节软骨细胞的原代高密度单层培养物施加流体诱导剪切。软骨细胞中的一氧化氮释放增加的持续时间和流体诱导剪切的幅度。在一氧化氮合酶抑制剂的存在下，剪切诱导的一氧化氮产生减少，但不受百日咳毒素，新霉素，四乙基氯化铵，或维拉帕米。一氧化氮合酶抑制剂，百日咳毒素，新霉素，但不是由四乙基氯化铵或维拉帕米阻断的糖胺聚糖合成的增加，在响应剪切应力。磷脂酶C抑制剂，新霉素，也减少了糖胺聚糖合成的情况下，流动诱导的剪切。正如这里所研究的，剪切应力增加软骨细胞的一氧化氮产生，剪切诱导的基质大分子代谢的变化受到一氧化氮合成的影响：G蛋白激活，磷脂酶C激活。
Mechanical loading alters the metabolism of articular cartilage, possibly due to effects of shear stress on chondrocytes. In cultured chondrocytes, glycosaminoglycan synthesis increases in response to fluid-induced shear. This study tested the hypothesis that shear stress increases nitric oxide production in chondrocytes, and nitric oxide then influences glycosaminoglycan metabolism. Inhibitors of nitric oxide synthase, G proteins, phospholipase C, potassium channels, and calcium channels were also analyzed for effects on nitric oxide release and glycosaminoglycan synthesis. Fluid-induced shear was applied to primary high-density monolayer cultures of adult bovine articular chondrocytes using a cone viscometer. Nitric oxide release in chondrocytes increased in response to the duration and the magnitude of the fluid-induced shear. Shear-induced nitric oxide production was reduced in the presence of nitric oxide synthase inhibitors but was unaffected by pertussis toxin, neomycin, tetraethyl ammonium chloride, or verapamil. The increase in glycosaminoglycan synthesis in response to shear stress was blocked by nitric oxide synthase inhibitors, pertussis toxin, and neomycin but not by tetraethyl ammonium chloride or verapamil. The phospholipase C inhibitor, neomycin, also decreased glycosaminoglycan synthesis in the absence of flow-induced shear. As studied here, shear stress increased nitric oxide production by chondrocytes, and the shear-induced change in matrix macromolecule metabolism was influenced by nitric oxide synthesis: G protein activation, and phospholipase C activation.