Campo G M, Avenoso A, Campo S, D'Ascola A, Traina P, Calatroni A
Department of Biochemical, School of Medicine, University of Messina, Policlinico Universitario, Messina, Italy.
Osteoarthritis Cartilage. 2008 Dec;16(12):1474-83. doi: 10.1016/j.joca.2008.04.002. Epub 2008 May 23.
Free radical damage, inflammation, and apoptosis play a critical role in the onset and progression of cartilage erosion in arthritis. Many studies have demonstrated that glycosaminoglycans (GAGs), and chondroitin-4-sulphate (C4S) in particular, possess antioxidant activity that is able to inhibit lipid peroxidation which is the main mechanism of free radical-mediated biological injury. In addition to the effect directly exerted by reactive oxygen species (ROS), the activation of nuclear factor kB (NF-kB) and caspases may contribute substantially to increase inflammation and cell damage. We studied whether the antioxidant action of chronic C4S treatment to reduce ROS injury involves NF-kB and caspases modulation using an experimental model of collagen-induced arthritis in mice.
Arthritis was induced in mice via an intradermal injection at the base of the tail of 100 microl of emulsion containing bovine type II collagen in complete Freund's adjuvant.
Arthritis provoked the following: severe oedema and inflammation in the hind paws; lipid peroxidation in the joints [measured by 8-isoprostane (8-IPE) levels]; reduction of the endogenous antioxidants catalase (CAT) activity and reduced glutathione (GSH) levels; induction of NF-kB translocation; a loss of cytoplasmic NF-kB inhibitor alpha (IkBalpha); an increase in metalloproteinase-13 (MMP-13), caspase-3 and caspase-7 gene expression and their related protein; the induction of cartilage polymorphonuclear (PMN) activation and infiltration [evaluated by elastase (ELA) assay] and cartilage alterations evaluated by histological analysis. Intraperitoneal administration of different doses of C4S (for 25 days), ameliorated all the symptoms of inflammation in the articular knee and paw joints, limited lipid peroxidation, inhibited NF-kB activation and IkBalpha protein loss, decreased mRNA MMP-13 and caspases expression and their related protein, restored endogenous antioxidants, and reduced PMN accumulation in the damaged cartilage.
The evidence that C4S was able to inhibit NF-kB and apoptosis activation supports the hypothesis that the C4S effect depends on reduction of ROS production, although other direct effects cannot be excluded.
自由基损伤、炎症和细胞凋亡在关节炎软骨侵蚀的发生和发展中起关键作用。许多研究表明，糖胺聚糖（GAGs），尤其是硫酸软骨素-4（C4S），具有抗氧化活性，能够抑制脂质过氧化，而脂质过氧化是自由基介导的生物损伤的主要机制。除了活性氧（ROS）直接发挥的作用外，核因子κB（NF-κB）和半胱天冬酶的激活可能在很大程度上导致炎症和细胞损伤的增加。我们使用小鼠胶原诱导性关节炎实验模型，研究了慢性C4S治疗减轻ROS损伤的抗氧化作用是否涉及NF-κB和半胱天冬酶的调节。
通过在小鼠尾巴根部皮内注射100微升含有牛II型胶原的完全弗氏佐剂乳剂诱导关节炎。
关节炎引发了以下情况：后爪严重水肿和炎症；关节中的脂质过氧化[通过8-异前列腺素（8-IPE）水平测量]；内源性抗氧化剂过氧化氢酶（CAT）活性降低和谷胱甘肽（GSH）水平降低；NF-κB易位的诱导；细胞质NF-κB抑制剂α（IkBα）的丧失；金属蛋白酶-13（MMP-13）、半胱天冬酶-3和半胱天冬酶-7基因表达及其相关蛋白增加；软骨多形核（PMN）激活和浸润的诱导[通过弹性蛋白酶（ELA）测定评估]以及通过组织学分析评估的软骨改变。腹腔注射不同剂量的C4S（持续25天），改善了膝关节和爪关节的所有炎症症状，限制了脂质过氧化，抑制了NF-κB激活和IkBα蛋白丧失，降低了MMP-13和半胱天冬酶的mRNA表达及其相关蛋白，恢复了内源性抗氧化剂，并减少了受损软骨中PMN的积累。
C4S能够抑制NF-κB和细胞凋亡激活的证据支持了C4S的作用取决于ROS产生减少的假设，尽管不能排除其他直接作用。
