title: Effect of psychological stress on the structure of the temporomandibular joint and the expression of MMP-3 and TIMP-3 in the cartilage in rats.
abstract: Our aim was to observe the effects of psychological stress on the structure of the temporomandibular joint (TMJ), and to evaluate the expression of matrix metallopeptidase-3 (MMP-3) and tissue inhibitor of metalloproteinase-3 (TIMP-3) in condylar chondrocytes in rats. The rats were divided into 3 groups of 12 according to the duration of psychological stress: 3 weeks or 6 weeks, and 6 weeks of recovery. A fourth group of 12 rats was used as controls. Each rat was evaluated by the open-field test and the weight measured. The results confirmed psychological stress in 24 of the 36 rats (67%). The tissues of the TMJ were stained with haematoxylin and eosin and pathological changes were studied under a light microscope. MMP-3 and TIMP-3 expression was investigated using the SP kit. The experimental groups showed thinning of articular cartilage, shedding of collagen fibres, cracks in the articular discs, and other structural changes that were aggravated with time, from three weeks to six weeks. The 6-week recovery group showed an improvement in these changes, which indicated the initiation of joint repair. The MMP-3 expression rate correlated with the degree of joint lesion, while the TIMP-3 rate showed an opposite trend and was highest in the 6-week recovery group. Our findings clearly indicate that psychological stress may play an important part in the development of TMJ diseases in rats; further studies should be made to extrapolate the results to other models before clinical use.
authors: Department of Stomatology, Second Affiliated Hospital of Xinjiang Medical University, People's Republic of China.
authors: Xu
authors: X
authors: Huang
authors: Department of Stomatology, Second Affiliated Hospital of Xinjiang Medical University, People's Republic of China.
authors: Haixia
authors: H
authors: Liu
authors: Department of Stomatology, Second Affiliated Hospital of Xinjiang Medical University, People's Republic of China.
authors: Peng
authors: P
authors: Xiao
authors: Department of Stomatology, Fifth Affiliated Hospital of Xinjiang Medical University, People's Republic of China.
authors: Yan
authors: Y
authors: Wang
authors: Department of Stomatology, Second Affiliated Hospital of Xinjiang Medical University, People's Republic of China.
authors: Hongyu
authors: H
authors: Zhang
mesh_terms: D000818:Animals; D001835:Body Weight; D001853:Bone Marrow / Q000201:enzymology / Q000473:pathology; D002358:Cartilage, Articular / Q000201:enzymology / Q000473:pathology*; D019902:Chondrocytes / Q000201:enzymology / Q000473:pathology; D003094:Collagen / Q000737:chemistry; D004195:Disease Models, Animal; D004558:Electric Stimulation; D017746:Joint Capsule / Q000201:enzymology / Q000473:pathology; D008297:Male; D008335:Mandibular Condyle / Q000201:enzymology / Q000473:pathology; D019278:Matrix Metalloproteinase 3 / Q000032:analysis*; D061965:Matrix Metalloproteinase Inhibitors / Q000032:analysis*; D055728:Primary Myelofibrosis / Q000201:enzymology / Q000473:pathology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000201:enzymology / Q000473:pathology*; D013583:Synovial Membrane / Q000201:enzymology / Q000473:pathology; D013701:Temporal Bone / Q000201:enzymology / Q000473:pathology; D013704:Temporomandibular Joint / Q000201:enzymology / Q000473:pathology*; D019224:Temporomandibular Joint Disc / Q000201:enzymology / Q000473:pathology; D013997:Time Factors; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000032:analysis*; D014945:Wound Healing / Q000502:physiology
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D019717:Tissue Inhibitor of Metalloproteinase-3; D003094:Collagen; D019278:Matrix Metalloproteinase 3
keywords: Matrix metalloproteinases-3; Psychological stress; Temporomandibular disorders; Tissue inhibitor of metalloproteinase-3