osteoprotegerin and Dermatitis--Atopic

Recent multiple studies have shown that the long-term consequences of atopic dermatitis (AD) include an increased risk of osteoporosis and fracture, especially an increase in hip, pelvic, spinal and wrist fractures. AD is very common worldwide, and some kinds of fractures, such as hip fractures, are associated with increased mortality, which has a substantial socioeconomic impact; however, the precise mechanisms for this remain unclear. Receptor activator of nuclear factor kappa-Β (RANK) ligand (RANKL) and osteoprotegerin (OPG) are members of the tumour necrosis factor ligand and receptor family, members of which also are known as bone biomarkers. Alterations in the RANKL/RANK/OPG system and the balance among these factors (represented by the RANKL/OPG ratio) are central to the pathogenesis of bone loss from osteoporosis, and it is postulated that there is a potential association between the serum levels of RANKL and OPG, and bone density or fracture. Recently, our research group demonstrated that the serum RANKL/OPG ratio positively correlated with AD severity and suggests fracture risk in older women with AD. This review summarizes and discusses the risk and mechanisms of osteoporotic fracture in AD. RANKL may be involved in the pathogenesis of AD, regarding not only bone abnormality but also inflammation. Although further investigation will be needed to verify the hypotheses, recent findings may provide new insights into the pathogenesis of AD and therapeutic targets.

Topics: Aged; Bone Density; Bone Density Conservation Agents; Dermatitis, Atopic; Female; Humans; Ligands; Osteoporosis; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Topics: Aged; Dermatitis, Atopic; Eczema; Female; Humans; Ligands; NF-kappa B; Osteoprotegerin; RANK Ligand

The aim of this study was to investigate how atopic dermatitis (AD) contributes to root resorption during orthodontic tooth movement.. Atopic dermatitis model mice and wild-type mice were subjected to an excessive orthodontic force (OF) to induce movement of the upper first molars. The expression levels of the tartrate-resistant acid phosphatase (TRAP), IL-17, IL-6, and RANKL proteins were determined in the periodontal ligament (PDL) by an immunohistochemical analysis. Furthermore, the effects of the compression force on co-cultures of CD4(+) cells from AD patients or healthy individuals and human PDL cells were investigated with regard to the levels of secretion and mRNA expression of IL-17, IL-6, RANKL, and osteoprotegerin.. The immunoreactivities for TRAP, IL-17, IL-6, and RANKL in the AD group were found to be significantly increased. The double immunofluorescence analysis for IL-17/CD4 detected immunoreaction. The secretion of IL-17, IL-6, and RANKL, and the mRNA levels of IL-6 and RANKL in the AD patients were increased compared with those in healthy individuals.. Th17 cells may therefore be associated with the deterioration of root resorption of AD mice, and may explain why AD patients are more susceptible to root resorption than healthy individuals when an excessive OF is applied.

Topics: Acid Phosphatase; Adult; Animals; CD4-Positive T-Lymphocytes; Cell Culture Techniques; Coculture Techniques; Dermatitis, Atopic; Disease Models, Animal; Female; Humans; Immunoglobulin E; Interleukin-17; Interleukin-6; Isoenzymes; Male; Mice; Mice, Inbred BALB C; Osteoprotegerin; Periodontal Ligament; RANK Ligand; Root Resorption; Stress, Mechanical; Tartrate-Resistant Acid Phosphatase; Th17 Cells; Tooth Movement Techniques; Young Adult