Proinflammatory cytokine-induced matrix metalloproteinase-9 expression in temporomandibular joint osteoarthritis is regulated by multiple intracellular mitogen-activated protein kinase pathways.

Objectives: Temporomandibular joint (TMJ) osteoarthritis (OA) is an inflammatory disease that involves periarthritis of the TMJ and destruction of cartilage tissue in the mandibular condyle. However, the role of proinflammatory cytokines in the expression levels of matrix metalloproteinase (MMP) remains inconclusive. Thus, in this study, we aimed to investigate the effect of proinflammatory cytokines on the expression of MMPs.

Connective tissue growth factor enhances TGF-β1-induced osteogenic differentiation via activation of p38 MAPK in mesenchymal stem cells.

Objectives: Cellular differentiation is based on the effects of various growth factors. Transforming growth factor (TGF)-β1 plays a pivotal role in inducing osteogenic differentiation of mesenchymal stem cells (MSCs). In this study, we investigated the influence of connective tissue growth factor (CTGF), known to function synergistically with TGF-β1, on osteogenic differentiation in MSCs.

Applicability of the seated step test for assessing thigh muscle sarcopenia in older individuals.

Assessment of lower limb muscle mass and related functions in older individuals is important because of their essential role in maintaining locomotion and activities of daily living. Therefore, a simple and reliable method for assessing these parameters should be established. The seated step test is easy and safe and can be used to assess lower limb agility; however, its relationship to skeletal muscle mass and function remains unknown.

Hydrogen peroxide-induced oxidative stress promotes expression of CXCL15/Lungkine mRNA in a MEK/ERK-dependent manner in fibroblast-like synoviocytes derived from mouse temporomandibular joint.

Objectives: Temporomandibular joint osteoarthritis (TMJ-OA) is a multifactorial disease caused by inflammation and oxidative stress. It has been hypothesized that mechanical stress-induced injury of TMJ tissues induces the generation of reactive oxygen species (ROS), such as hydroxyl radical (OH∙), in the synovial fluid (SF). In general, the overproduction of ROS contributes to synovial inflammation and dysfunction of the subchondral bone in OA.

Extracellular adenosine 5'-diphosphate promotes MCP-1/CCL2 expression via the P2Y purinergic receptor/ERK signaling axis in temporomandibular joint-derived mouse fibroblast-like synoviocytes.

Background: Temporomandibular joint osteoarthritis (TMJ-OA) causes cartilage degeneration, bone cavitation, and fibrosis of the TMJ. However, the mechanisms underlying the fibroblast-like synoviocyte (FLS)-mediated inflammatory activity in TMJ-OA remain unclear.

Methods And Results: Reverse transcription-quantitative polymerase chain reaction analysis revealed that the P2Y, P2Y, and P2Y purinergic receptor agonist adenosine 5'-diphosphate (ADP) significantly induces monocyte chemotactic protein 1 (MCP-1)/ C-C motif chemokine ligand 2 (CCL2) expression in the FLS1 synovial cell line.