Osteoarthritis (OA) is the most common joint disease, characterized by progressive destruction of the articular cartilage. The surface of joint cartilage is the first defensive and affected site of OA, but our knowledge of genesis and homeostasis of this superficial zone is scarce. EGFR signaling is important for tissue homeostasis.
STING regulates abnormal bone formation induced by deficiency of DNase II
Comparison of tissue transglutaminase 2 and bone biological markers osteocalcin, osteopontin and sclerostin expression in human osteoporosis and osteoarthritis
Bone marrow lesions in hip osteoarthritis are characterized by increased bone turnover and enhanced angiogenesis
This study indicates that BML are characterized by increased bone turnover, vascularity and angiogenesis in keeping with it being a reparatory process. Thus, the water signal, which is the hallmark of BML on MRI, is most probably reflecting increased tissue vascularity accompanying increased remodeling activity.
Rebamipide Attenuates Mandibular Condylar Degeneration in a Murine Model of TMJ-OA by Mediating a Chondroprotective Effect and by Downregulating RANKL-Mediated Osteoclastogenesis
Authors
Takashi Izawa , Hiroki Mori, Tekehiro Shinohara, Akiko Mino-Oka, Islamy Rahma Hutami, Akihiko Iwasa, Eiji Tanaka
Abstract
Abstractemporomandibular joint osteoarthritis (TMJ-OA) is characterized by progressive degradation of cartilage and changes in subchondral bone. It is also one of the most serious subgroups of temporomandibular disorders. Rebamipide is a gastroprotective agent that is currently used for the treatment of gastritis and gastric ulcers. It scavenges reactive oxygen radicals and has exhibited anti-inflammatory potential. The aim of this study was to investigate the impact of rebamipide both in vivo and in vitro on the development of cartilage degeneration and osteoclast activity in an experimental murine model of TMJ-OA, and to explore its mode of action. Oral administration of rebamipide (0.6 mg/kg and 6 mg/kg) was initiated 24 h after TMJ-OA was induced, and was maintained daily for four weeks. Rebamipide treatment was found to attenuate cartilage degeneration, to reduce the number of apoptotic cells, and to decrease the expression levels of matrix metalloproteinase-13 (MMP-13) and inducible nitric oxide synthase (iNOS) in TMJ-OA cartilage in a dose-dependent manner. Rebamipide also suppressed the activation of transcription factors (e.g., NF-κB, NFATc1) and mitogen-activated protein kinases (MAPK) by receptor activator of nuclear factor kappa-B ligand (RANKL) to inhibit the differentiation of osteoclastic precursors, and disrupted the formation of actin rings in mature osteoclasts. Together, these results demonstrate the inhibitory effects of rebamipide on cartilage degradation in experimentally induced TMJ-OA. Furthermore, suppression of oxidative damage, restoration of extracellular matrix homeostasis of articular chondrocytes, and reduced subchondral bone loss as a result of blocked osteoclast activation suggest that rebamipide is a potential therapeutic strategy for TMJ-OA.
Link to Article
http://dx.doi.org/10.1371/journal.pone.0154107
Influence of age and gender on microarchitecture and bone remodeling in subchondral bone of the osteoarthritic femoral head
Authors
Guangyi Li, Qiujian Zheng, Euphemie Landao-Bassonga, Tak S. Cheng, Nathan J. Pavlos, Yuanchen Ma, Changqing Zhang, Ming H. Zheng
Abstract
Introduction Age and gender have been reported to have a remarkable impact on bone homeostasis. However, subchondral bone, which plays a pivotal role in the initiation and progression of OA, has been poorly investigated in this area. This study was to investigate age- and gender- related changes of microarchitecture and bone remodeling in subchondral bone in OA.
Methods Subchondral trabecular bone (STB) and deeper trabecular bone (DTB) specimens were extracted in the load-bearing region of femoral heads from 110 patients with OA. Micro-CT and histomorphometry were performed to analyze microarchitectural and bone remodeling changes of all specimens.
Results Compared to DTB, STB showed more sclerotic microarchitecture, more active bone remodeling and higher frequency of bone cysts. There were no gender differences for both microarchitecture and bone remodeling in STB. However, gender differences were found in DTB, with thinner Tb.Th, higher Tb.N, higher OS/BV and ES/BV in males. In both STB and DTB, no correlation between microarchitecture and age was found in both genders. However, bone remodeling of STB increased significantly with age in males, while bone remodeling of DTB increased significantly with age in females. No age or gender preference was found in subchondral bone cysts (SBCs) frequency. The cyst volume fraction was correlated with neither age nor gender.
Conclusions There were distinct differences in microarchitecture and bone remodeling between STB and DTB, which may be due to the distinct biomechanical and biochemical functions of these two bone structures in maintaining joint homeostasis. OA changed the normal age- and gender-dependence of bone homeostasis in joints, in a site-specific manner.