Genistein inhibits chondrogenic differentiation and mineralization of ATDC5 cells

Injectable cartilage microtissues based on 3D culture using porous gelatin microcarriers for cartilage defect treatment

Cartilage tissues possess an extremely limited capacity for self-repair, and current clinical surgical approaches for treating articular cartilage defects can only provide short-term relief. Despite significant advances in the field of cartilage tissue engineering, avoiding secondary damage caused by invasive surgical procedures remains a challenge. In this study, injectable cartilage microtissues were developed through 3D culture of rat bone marrow mesenchymal stem cells (BMSCs) within porous gelatin microcarriers (GMs) and induced differentiation. These microtissues were then injected for the purpose of treating cartilage defects in vivo, via a minimally invasive approach. GMs were found to be noncytotoxic and favorable for cell attachment, proliferation and migration evaluated with BMSCs. Moreover, cartilage microtissues with a considerable number of cells and abundant extracellular matrix components were obtained from BMSC-laden GMs after induction differentiation culture for 28 days. Notably, ATDC5 cells were complementally tested to verify that the GMs were conducive to cell attachment, proliferation, migration and chondrogenic differentiation. The microtissues obtained from BMSC-laden GMs were then injected into articular cartilage defect areas in rats and achieved superior performance in alleviating inflammation and repairing cartilage. These findings suggest that the use of injectable cartilage microtissues in this study may hold promise for enhancing the long-term outcomes of cartilage defect treatments while minimizing the risk of secondary damage associated with traditional surgical techniques.

Formononetin, a Beer Polyphenol with Catabolic Effects on Chondrocytes

Beer consumption has been identified as a risk factor for osteoarthritis (OA), a rheumatic disease characterised by cartilage degradation, joint inflammation, and eventual joint failure. One of the main isoflavonoids in beer is formononetin (FNT), an estrogenic compound also found in multiple plants and herbs. In this study, we aimed to investigate the effect of FNT on chondrocyte viability, inflammation, and metabolism. Cells were treated with FNT with or without IL-1β for 48 h and during 7 days of differentiation. Cell viability was determined via MTT assay. Nitrite accumulation was determined by Griess reaction. The expression of genes involved in inflammation and metabolism was determined by RT-PCR. The results revealed that a low concentration of FNT had no deleterious effect on cell viability and decreased the expression of inflammation-related genes. However, our results suggest that FNT overexposure negatively impacts on chondrocytes by promoting catabolic responses. Finally, these effects were not mediated by estrogen receptors (ERs) or aryl hydrocarbon receptor (AhR). In conclusion, factors that favour FNT accumulation, such as long exposure times or metabolic disorders, can promote chondrocyte catabolism. These data may partially explain why beer consumption increases the risk of OA.

The protective activity of genistein against bone and cartilage diseases

Genistein, a natural isoflavone rich in soybean and leguminous plants, has been shown various biological effects, such as anti-inflammation, anti-oxidation, anti-cancer, and bone/cartilage protection. Due to the structural similarity to estrogen, genistein exhibits estrogen-like activity in protecting against osteoporosis and osteoarthritis. Furthermore, genistein has been considered as an inhibitor of tyrosine kinase, which has been found to be dysregulated in the pathological development of osteoporosis, osteoarthritis, and intervertebral disc degeneration (IDD). Many signaling pathways, such as MAPK, NF-κB, and NRF2/HO-1, are involved in the regulatory activity of genistein in protecting against bone and cartilage diseases. The potential molecular mechanisms of genistein in therapeutic management of bone and cartilage diseases have been investigated, but remain to be fully understood. In this article, we mainly discuss the current knowledge of genistein in protecting against bone and cartilage diseases, such as osteoporosis, osteoarthritis, rheumatoid arthritis (RA), and IDD.