Role of signaling pathways in age-related orthopedic diseases: focus on the fibroblast growth factor family.

Fibroblast growth factor (FGF) signaling encompasses a multitude of functions, including regulation of cell proliferation, differentiation, morphogenesis, and patterning. FGFs and their receptors (FGFR) are crucial for adult tissue repair processes. Aberrant FGF signal transduction is associated with various pathological conditions such as cartilage damage, bone loss, muscle reduction, and other core pathological changes observed in orthopedic degenerative diseases like osteoarthritis (OA), intervertebral disc degeneration (IVDD), osteoporosis (OP), and sarcopenia. In OA and IVDD pathologies specifically, FGF1, FGF2, FGF8, FGF9, FGF18, FGF21, and FGF23 regulate the synthesis, catabolism, and ossification of cartilage tissue. Additionally, the dysregulation of FGFR expression (FGFR1 and FGFR3) promotes the pathological process of cartilage degradation. In OP and sarcopenia, endocrine-derived FGFs (FGF19, FGF21, and FGF23) modulate bone mineral synthesis and decomposition as well as muscle tissues. FGF2 and other FGFs also exert regulatory roles. A growing body of research has focused on understanding the implications of FGF signaling in orthopedic degeneration. Moreover, an increasing number of potential targets within the FGF signaling have been identified, such as FGF9, FGF18, and FGF23. However, it should be noted that most of these discoveries are still in the experimental stage, and further studies are needed before clinical application can be considered. Presently, this review aims to document the association between the FGF signaling pathway and the development and progression of orthopedic diseases. Besides, current therapeutic strategies targeting the FGF signaling pathway to prevent and treat orthopedic degeneration will be evaluated.

Publication Trends for Sarcopenia in the World: A 20-Year Bibliometric Analysis.

BACKGROUND: Sarcopenia, an age-related degenerative disease, seriously affects the health and quality of life of the elder. The research of sarcopenia has changed dramatically around the world. This article aims to analyze global trends in this field over the past 20 years. METHODS: "Sarcopenia" was used as the search term to retrieve relevant publications from the WOS and PubMed databases. Co-occurrence, literature coupling, co-citation, and co-author analysis were performed by using the software VOS viewer. We analyzed the trends of sarcopenia research over the last 20 years from different aspects, such as the number of papers, total citations, average citations per item, h-index, research area, article types, institutions, country, journals, and funding. RESULTS: We retrieved 13,421 research articles published on sarcopenia between 2001 and 2020. The results showed that the USA made the highest contributions to this field. Geriatrics gerontology is the most study classification of sarcopenia. Basic research on sarcopenia in geriatric gerontology accounts for approximately 16.496% of global publications. The Osteoporosis International published the largest number of sarcopenia-related studies. The United States Department of Health Human Services was the leading funding organization, which sponsored 1,604 articles. CONCLUSION: Global sarcopenia research increased rapidly from 2001 to 2020, especially recently. The research leader of sarcopenia is the USA. In the future, the study of sarcopenia will continue to focus on aging, nutrition, and exercise and will delve deeper into molecular mechanisms. On the other hand, revealing the link between sarcopenia and other diseases will be the next research hotspot.