Role of synovial membrane inflammation in cartilage matrix breakdown in the Pond‐Nuki dog model of osteoarthritis

182

114

Objective. Osteoarthritis (OA) is one of the most prevalent and disabling chronic conditions affecting the elderly. Its etiology is largely unknown, but age is the most prominent risk factor. The current study was designed to test whether accumulation of advanced glycation end products (AGEs), which are known to adversely affect cartilage turnover and mechanical properties, provides a molecular mechanism by which aging contributes to the development of OA.Methods. The hypothesis that elevated AGE levels predispose to the development of OA was tested in the canine anterior cruciate ligament transection (ACLT) model of experimental OA. Cartilage AGE levels were enhanced in young dogs by intraarticular injections of ribose. This mimics the accumulation of AGEs without the interference of other age-related changes. The severity of OA was then assessed 7 weeks after ACLT surgery in dogs with normal versus enhanced AGE levels.Results. Intraarticular injections of ribose enhanced cartilage AGE levels ϳ5-fold, which is similar to the normal increase that is observed in old dogs. ACLT surgery resulted in more-pronounced OA in dogs with enhanced AGE levels. This was observed as increased collagen damage and enhanced release of proteoglycans. The attempt to repair the matrix damage was impaired; proteoglycan synthesis and retention were decreased at enhanced AGE levels. Mankin grading of histology sections also revealed more-severe OA in animals with enhanced AGE levels.Conclusion. These findings demonstrate increased severity of OA at higher cartilage AGE levels and provide the first in vivo experimental evidence for a molecular mechanism by which aging may predispose to the development of OA.The population of Western society is aging rapidly. Consequently, age-related diseases will increase greatly over the coming decades and will have a great impact on the quality of life of the elderly. Osteoarthritis (OA) is one of the most prevalent and disabling chronic conditions affecting the elderly and poses a significant public health problem (1). The most prominent feature of OA is the progressive destruction of articular cartilage, resulting in impaired joint motion, severe pain, and, ultimately, disability (2). As yet, the etiology of OA remains largely unknown. The incidence of OA increases with age: Ͼ50% of the population over 60 years of age is affected (3,4). Although age is identified as the main risk factor for the development of OA, the mechanism by which aging is involved remains unclear. Age-related changes in the articular cartilage are expected to play an important role in the susceptibility of cartilage to OA.Articular cartilage derives its mechanical properties from its extracellular matrix. This matrix is composed of type II collagen, which forms a 3-dimensional network that provides the cartilage with resistance to tensile forces (5).

Section: Methodsmentioning

confidence: 99%

Accumulation of advanced glycation end products as a molecular mechanism for aging as a risk factor in osteoarthritis

DeGroot¹,

Verzijl²,

Wijk

et al. 2004

182

114

“…The animals were randomly divided into 5 experimental groups: 7 dogs were operated and left untreated (untreated OA group); 6 were operated and treated with omeprazole (20 mg/day orally; Astra Pharma, Mississauga, Ontario, Canada); 6 were operated and treated with diclofenac (0.25 mglkg twice daily orally; Sigma, St. Louis, MO) plus omeprazole (20 mg/day orally); 6 were operated and treated with tenidap (3 mg/kg twice daily orally; Pfizer Central Research, Groton, CT) plus omeprazole (20 mg/day orally); 8 were not operated (normal controls). Omeprazole was given to drug-treated dogs because of their gastrointestinal sensitivity to antirheumatic drugs; omeprazole proved to fully protect the animals against drug-related gastrointestinal side effects that had been encountered during preliminary studies.…”

Section: Methodsmentioning

confidence: 99%

“…Cartilage lesions are probably related to mechanical as well as biochemical factors, including the enzymatic cleavage of matrix macromolecules (4). Matrix metalloproteases (MMP), such as collagenase and stromelysin, have been found to be significantly increased in OA cartilage and synovial membrane, in humans as well as in the experimental dog model (4)(5)(6). It is becoming more and more evident that MMP play an important role in cartilage destruction.…”

mentioning

confidence: 99%

Effects of tenidap on canine experimental osteoarthritis i. morphologic and metalloprotease analysis

Fernandes

Martel‐Pelletier

Otterness

et al. 1995

Self Cite

Objective. To examine the effects of tenidap and diclofenac on osteoarthritic lesions and metalloprotease activity in experimental osteoarthritis (OA).Methods. The anterior cruciate ligament of the right stifle joint of 25 mongrel dogs was sectioned by a stab wound. Seven dogs received no treatment, 6 were treated with oral omeprazole (20 mg/day), another 6 were treated with diclofenac (0.25 mg/kg/twice daily) plus omeprazole (20 mg/day), and 6 received oral tenidap (3 mg/kg/twice daily) plus omeprazole (20 mg/ day). The dogs received medication for 8 weeks; all dogs were killed at the end of this period. Eight normal dogs were used as controls. Lesions were evaluated macroscopically for the incidence and size of osteophytes and the area and grade of cartilage erosions on the condyles and plateaus, along with histologic evaluation of the severity of the cartilage lesions and synovial inflammation. Stromelysin and collagenase activities and the collagenase messenger RNA (mRNA) level were measured in cartilage and synovial membrane.Results. Compared with the untreated or omeprazole-treated OA groups, the dogs treated with tenidap exhibited significant reduction in the incidence (P 5 0.001) and size (P 5 0.0001) of osteophytes. Tenidap also significantly decreased the size and grade of cartilage macroscopic lesions, as well as the histologic severity of cartilage lesions on both condyles and plateaus. The histologic severity of synovial inflammatory reaction was also significantly reduced (P I 0.003) in the tenidap group. Tenidap markedly decreased stromelysin and collagenase activity in both cartilage (stromelysin P I 0.003; collagenase P I 0.01) and synovial membrane (stromelysin P 5 0.003; collagenase P 5 0.005). Moreover, tenidap also decreased the collagenase mRNA level in cartilage (P 5 0.005) and synovial membrane (P 5 0.002). Diclofenac slightly reduced the incidence and size of osteophytes and cartilage lesions, but these changes were not statistically significant. Diclofenac had no effect on the severity of synovial inflammation, metalloprotease activity, or collagenase expression.Conchsion. This study showed that tenidap had a more potent anti-osteoarthritic effect than diclofenac in this model. The effect of the drug in suppressing metalloprotease synthesis, a process known to play a major role in the pathophysiology of osteoarthritic lesions, may explain its mechanism of action.Transection of the anterior cruciate ligament of the dog knee leads to articular changes which resemble the morphologic and biochemical changes seen in human osteoarthritis (OA) (1-3). Cartilage lesions are probably related to mechanical as well as biochemical factors, including the enzymatic cleavage of matrix macromolecules (4). Matrix metalloproteases (MMP), such as collagenase and stromelysin, have been found to be significantly increased in OA cartilage and synovial membrane, in humans as well as in the experimental dog model (4-6). It is becoming more and more

“…Many laboratories, includ-ing our own, have shown that the Pond-Nuki dog model of OA, produced by sectioning the anterior cruciate ligament of the knee (l6), induces histologic and biochemical changes similar to those in human OA (7,17,18). These include increased levels of proteolytic enzymes in OA cartilage (2,6,7) and synovial inflammation (19). We have previously demonstrated with this model that corticosteroids can suppress the in vivo increase in metalloproteases (6,19).…”

Section: Protective Effects O F Corticosteroids On Cartilage Lesions mentioning

confidence: 98%

Protective effects of corticosteroids on cartilage lesions and osteophyte formation in the pond‐nuki dog model of osteoarthritis

Pelletier

Martel‐Pelletier

1989

Self Cite

148

The in vivo effects of corticosteroids on osteoarthritic (OA) lesions were examined in 12 dogs in which the anterior cruciate ligament had been sectioned. Six were treated with oral prednisone and 6 were treated with intraarticular (IA) injections of triamciaolone hexacetonide (TH), at surgery and 4 weeks later. Twelve other operated dogs received no treatment. All dogs were killed 8 weeks postsurgery. Four of 15 normal control dogs received IA TH injections. Operated untreated dogs developed significant cartilage lesions on the femoral condyles and tibial plateaus with prominent osteophytes. Operated dogs treated orally or with IA injections had a significant reduction in osteophyte size.Cartilage erosions on femoral condyles were observed in 25% of the untreated dogs, 8% of the dogs receiving oral prednisone, and none of the dogs receiving IA TH. In both groups of treated dogs, the size of the tibial plateau lesions was significantly reduced compared with the operated untreated dogs. Histologically, corticosteroids significantly reduced the severity of OA structural changes of the cartilage on both medial and lateral femoral condyles and tibial plateaus in operated animals, with the exception of the lateral plateaus of those