TNF-α plays a key role in the development of rheumatoid arthritis (RA) and inflammatory bone loss. Unfortunately, treatment of RA with anti-inflammatory glucocorticoids (GCs) also causes bone loss resulting in osteoporosis. Our previous studies showed that overexpression of glucocorticoid-induced leucine zipper (GILZ), a mediator of GC’s anti-inflammatory effect, can enhance osteogenic differentiation in vitro and bone acquisition in vivo.
The anti-rheumatic efficacy of grape powder (GP) diet was evaluated in transgenic mice (TG) overexpressing human tumor necrosis factor (TNF), a model for rheumatoid arthritis (RA). After 4-weeks, TG mice fed on 10% of GP showed improvement with epiphyseal bone mass (p = 0.07) compared to TG fed on a regular diet. TG mice that received 5 or 10% of GP exhibited a significant (p < 0.05) decrease in resorption-associated osteoclasts in paw and knee joints.
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.
Cytosolic DNA sensors detect microbial DNA and promote type I interferon and pro-inflammatory cytokine production through the adaptor stimulator of interferon genes (STING) to resolve infection. Endogenous DNA also engages the STING pathway, contributing to autoimmune disease.
Osteoporosis (OP) and osteoarthritis (OA) are the most common joint diseases, with a high incidence in the elderly population. OP is characterized by trabecular bone remodeling and reabsorption, whereas articular cartilage and subchondral bone remodeling are major features of OA.
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.