Interleukin 6 promotes BMP9-induced osteoblastic differentiation through Stat3/mTORC1 in mouse embryonic fibroblasts

Exploring the Role of Hormones and Cytokines in Osteoporosis Development

The disease of osteoporosis is characterized by impaired bone structure and an increased risk of fractures. There is a significant impact of cytokines and hormones on bone homeostasis and the diagnosis of osteoporosis. As defined by the World Health Organization (WHO), osteoporosis is defined as having a bone mineral density (BMD) that is 2.5 standard deviations (SD) or more below the average for young and healthy women (T score < -2.5 SD). Cytokines and hormones, particularly in the remodeling of bone between osteoclasts and osteoblasts, control the differentiation and activation of bone cells through cytokine networks and signaling pathways like the nuclear factor kappa-B ligand (RANKL)/the receptor of RANKL (RANK)/osteoprotegerin (OPG) axis, while estrogen, parathyroid hormones, testosterone, and calcitonin influence bone density and play significant roles in the treatment of osteoporosis. This review aims to examine the roles of cytokines and hormones in the pathophysiology of osteoporosis, evaluating current diagnostic methods, and highlighting new technologies that could help for early detection and treatment of osteoporosis.

U-shaped relationship found between fibrinogen-to-albumin ratio and systemic inflammation response index in osteoporotic fracture patients

The relationship between the Systemic Inflammatory Response Index (SIRI) and the Fibrinogen-to-albumin ratio (FAR) has not been extensively investigated. The objective of this study was to determine the independent relationship between FAR and SIRI in people with osteoporotic fractures (OPF). A cross-sectional study was conducted using retrospective data from 3431 hospitalized OPF patients. The exposure variable in this study was the baseline FAR, while the outcome variable was the SIRI. Covariates, including age, gender, BMI, and other clinical and laboratory factors, were adjusted. Cross-correlation analysis and linear regression models were applied. The generalized additive model (GAM) investigated non-linear relationships. Adjusted analysis revealed an independent negative association between FAR and SIRI in OPF patients (β = - 0.114, p = 0.00064, 95% CI - 0.180, - 0.049). A substantial U-shaped association between FAR and SIRI was shown using GAM analysis (p < 0.001). FAR and SIRI indicated a negative association for FAR below 6.344% and a positive correlation for FAR over 6.344%. The results of our study revealed a U-shaped relationship between SIRI and FAR. The lowest conceivable FAR for a bone-loose inflammatory disease might be 6.344%, suggesting that this has particular significance for the medical diagnosis and therapy of persons with OPF. Consequently, the term "inflammatory trough" is proposed. These results offer fresh perspectives on controlling inflammation in individuals with OPF and preventing inflammatory osteoporosis.

Cytokines: The links between bone and the immune system

Osteoporosis results from an imbalance in a highly balanced physiological process called bone remodeling, in which osteoclast-mediated bone resorption and osteoblast-mediated bone formation play important roles. Osteoimmunology is a newly discovered interdisciplinary research field that focuses on the relationship between bone and the immune system. Specifically, bone and the immune system interact through cytokines, immune cells secrete cytokines, and cytokines finely regulate bone metabolism by mediating the differentiation and activity of osteoclasts and osteoblasts. Therefore, understanding the influence of cytokines on bone metabolism is conducive for the development of novel targeted drugs against immune-related bone diseases. This review summarizes the pathophysiological functions of various common cytokines in bone and discusses the potential clinical value of multiple cytokines in immune-mediated bone diseases.