Tumour necrosis factor-alpha and apoptosis in the rat temporomandibular joint.
The purpose of this investigation was to investigate the roles that tumour necrosis factor-alpha (TNF-alpha) and apoptosis play during acute inflammation of the temporomandibular joint (TMJ). Adult male Sprague-Dawley rats were injected with complete Freund's adjuvant (CFA) into the TMJ or kept as uninjected controls. The TMJ tissues were removed 2 days post-injection to mimic conditions of acute inflammation and analysed for changes in expression of TNF-alpha, the receptor TNF-R1, caspase-3 and -8, and apoptosis. Concentrations of TNF-alpha, TNF-R1, caspase-3 and -8, and apoptosis were significantly elevated in CFA-injected animals compared to uninjected controls. Tissue incubation with TNF-alpha caused a significant increase in caspase-3 and -8. Also, levels of apoptosis were significantly increased during inflammation, which could be inhibited by the addition of either anti-TNF-alpha neutralising antibody or caspase inhibitors. TNF-alpha may play a significant role in the onset of acute CFA-induced TMJ inflammation, and activation of apoptosis signalling pathways may be involved.
Department of Biomedical Sciences, Baylor College of Dentistry-The Texas A&M University System Health Science Center, 3302 Gaston Avenue, Dallas, TX 75246, USA. rspears@tambcd.edu
Robert
R
Spears
Raenie
R
Oakes
Larry L
LL
Bellinger
Bob
B
Hutchins
D000208:Acute Disease; D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases / Q000032:analysis; D004789:Enzyme Activation; D020287:In Situ Nick-End Labeling; D008297:Male; D018613:Microscopy, Confocal; D023421:Models, Animal; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D018124:Receptors, Tumor Necrosis Factor / Q000032:analysis; D047888:Receptors, Tumor Necrosis Factor, Type I; D013704:Temporomandibular Joint / Q000276:immunology*; D013705:Temporomandibular Joint Disorders / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000502:physiology*
D015703:Antigens, CD; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha; C505410:Casp3 protein, rat; C505528:Casp8 protein, rat; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases