Evidence of reactive oxygen species generation in synovial fluid from patients with temporomandibular disease by electron spin resonance spectroscopy

Abstract

Reactive oxygen species (ROS) have been implicated in the pathogenesis of temporomandibular disorders. In the present study, we provide the first evidence of ROS generation in the synovial fluid from human temporomandibular disorder patients, as shown by electron spin resonance (ESR) and spin trapping. Three distinct ESR spectra of DMPO spin adducts were observed in the synovial fluid. They corresponded to three free radical species: hydroxyl radical (HO(*)), hydrogen radical (H(*)), and carbon-center radical (R(*)). Among them, the 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)-OH spectrum was the most prominent, suggesting that HO(*) was dominantly generated in the synovial fluid from temporomandibular disorder patients. Desferrioxamine (DFO), an iron chelator, strongly depressed the DMPO-OH signal intensity in the synovial fluid from patients with temporomandibular disorders. We successfully demonstrated ROS-induced oxidative stress in the synovial fluid from temporomandibular disorder patients. ROS generation in the temporomandibular joint could lead to exacerbation of inflammation and activation of cartilage matrix degrading enzymes that proceed to degenerative change of the temporomandibular joint. Thus, iron-dependent generation of HO( *) might have a crucial role in the pathogenesis of temporomandibular disorders.

Oxidative stress and temporomandibular joint disorders

“…Interestingly, these results are consistent with the ESR spectra obtained from SF in the TMD patients (Fig. 4) [7].…”

“…We have developed an ESR-based technique to detect free radical reactions in biological system in vitro or in vivo. Using the ESR-spin trapping technique, we have previously demonstrated that hydroxyl radical (HO ) could be generated by catalytic reaction of H 2 O 2 with free iron ions (Fenton reaction) in the IL-1a-induced TMJ rat arthritis model or in synovial fluid (SF) of the TMD patients [6,7]. In the present review, we discussed the oxidative stress related to the pathogenesis of the TMD, and demonstrate that the improvement of the oxidative stress would raise the possibility of constructing novel treatment strategies for TMD.…”

Oxygen consumption of equine articular chondrocytes: Influence of applied oxygen tension and glucose concentration during culture

“…In this paper our aim was mature chondrocytes culture not for multiplication but for the study of the effects of anoxia/ re-oxygenation, which is considered to occur in vivo (James et al, 1990;McIlwraith, 1996;Dimock et al, 2000;Lee et al, 2004). We cultured the cells under 5% or 21% O 2 , as regulated in the gas phase, with variable glucose concentrations: 0 g/L as an extreme condition, 1.0 g/L similar to in vivo conditions (Liberg et al, 1977), and 4.5 g/L because this glucose concentration is commonly used for the culture of articular chondrocytes.…”

Inflammatory markers in temporomandibular joint disorders

“…Although, that studies allowed understand the mechanisms of pathophysiology of the TMJ disorders, and give the assumption for treatment approach. There are also possibilities of applying the electron spin resonance (ESR) in diagnosis of reactive oxygen species (ROS) in the synovial fluid from temporomandibular disorder patients [34]. ROS correspond to free radical species and could exacerbate the inflammatory process and activate the cartilage matrix degrading enzymes, what leads to OA.…”