Pelletier J P, Jovanovic D V, Lascau-Coman V, Fernandes J C, Manning P T, Connor J R, Currie M G, Martel-Pelletier J
Hôpital Notre-Dame, Centre Hospitalier de l'Université de Montréal, Quebec, Canada.
Arthritis Rheum. 2000 Jun;43(6):1290-9. doi: 10.1002/1529-0131(200006)43:6<1290::AID-ANR11>3.0.CO;2-R.
To evaluate the in vivo therapeutic efficacy of N-iminoethyl-L-lysine (L-NIL), a selective inhibitor of inducible nitric oxide synthase, on the progression of structural lesions in the experimental canine model of osteoarthritis (OA), and to explore the effect of L-NIL on the level of chondrocyte apoptosis and of important proteins involved in the apoptotic phenomenon, i.e., caspase 3 (inducer) and Bcl-2 (inhibitor).
The OA model was created by sectioning the anterior cruciate ligament. Dogs were placed into 4 experimental groups: unoperated dogs that received no treatment (controls), operated (OA) dogs that received placebo treatment, OA dogs that received oral L-NIL at 10 mg/kg/day, and OA dogs that received oral L-NIL at 1.0 mg/kg/day. In both L-NIL groups, treatment started immediately after surgery. The OA dogs were killed at 12 weeks after surgery.
OA dogs treated with L-NIL showed a reduction in the size of osteophytes and a significant decrease in the severity of macroscopic and histologic cartilage lesions on both condyles and plateaus, compared with untreated OA dogs. L-NIL treatment also significantly decreased metalloprotease activity in cartilage. Immunohistochemical analysis revealed that the levels of chondrocyte apoptosis, caspase 3, and Bcl-2 were markedly increased in OA cartilage (P < 0.0001). A positive correlation between the levels of chondrocyte apoptosis and levels of caspase 3 was found (r = 0.54, P < 0.0001). OA dogs treated with the higher dosage L-NIL showed significantly reduced levels of chondrocyte apoptosis (P < 0.003) and caspase 3 (P < 0.04), but no effect on the increased level of Bcl-2 was demonstrated.
This study shows that L-NIL reduces the progression of experimental OA. This effect could be related to a reduced level of chondrocyte apoptosis and is likely mediated by a decrease in the level of caspase 3 activity. A sparing effect of L-NIL on the increased level of Bcl-2 may also be a contributing factor.
评估诱导型一氧化氮合酶选择性抑制剂N-亚氨基乙基-L-赖氨酸（L-NIL）在实验性犬骨关节炎（OA）模型中对结构损伤进展的体内治疗效果，并探讨L-NIL对软骨细胞凋亡水平以及凋亡现象中涉及的重要蛋白质（即半胱天冬酶3（诱导剂）和Bcl-2（抑制剂））水平的影响。
通过切断前交叉韧带建立OA模型。将犬分为4个实验组：未手术且未接受治疗的犬（对照组）、接受安慰剂治疗的手术（OA）犬、每天口服10mg/kg L-NIL的OA犬以及每天口服1.0mg/kg L-NIL的OA犬。在两个L-NIL组中，治疗均在手术后立即开始。OA犬在术后12周处死。
与未治疗的OA犬相比，用L-NIL治疗的OA犬骨赘大小减小，髁和平台的宏观和组织学软骨损伤严重程度显著降低。L-NIL治疗还显著降低了软骨中的金属蛋白酶活性。免疫组织化学分析显示，OA软骨中软骨细胞凋亡、半胱天冬酶3和Bcl-2水平显著升高（P<0.0001）。发现软骨细胞凋亡水平与半胱天冬酶3水平呈正相关（r=0.54，P<0.0001）。用较高剂量L-NIL治疗的OA犬软骨细胞凋亡水平（P<0.003）和半胱天冬酶3水平（P<0.04）显著降低，但对升高的Bcl-2水平未显示出影响。
本研究表明L-NIL可减轻实验性OA的进展。这种作用可能与软骨细胞凋亡水平降低有关，并且可能由半胱天冬酶3活性水平降低介导。L-NIL对升高的Bcl-2水平的保护作用也可能是一个促成因素。
