Fuyuan Decoction Enhances SOX9 and COL2A1 Expression and Smad2/3 Phosphorylation in IL-1β-Activated Chondrocytes

Fuzi decoction ameliorates pain and cartilage degeneration of osteoarthritic rats through PI3K-Akt signaling pathway and its clinical retrospective evidence

BACKGROUND

Osteoarthritis (OA) is a difficult disease but the clinic lacks effective therapy. As a classic formula of traditional Chinese medicine (TCM), Fuzi decoction (FZD) has been clinically applied for treating OA-related syndromes, but its anti-OA efficacy and mechanism remain unclear.

PURPOSE

To experimentally and clinically determine the anti-OA efficacy of FZD and clarify the underlying mechanism.

METHODS

UPLC/MS/MS was applied to identify the main components of FZD. A monoiodoacetate (MIA)-induced OA rat model was employed to evaluate the in vivo efficacy of FZD against OA, by using pain behavior assessment, histopathological observation, and immunohistochemical analysis. Primary rat chondrocytes were isolated to determine the in vitro effects of FZD by using cell viability assay, wound healing assay, and real-time PCR (qPCR) analysis on anabolic/catabolic mRNA expressions. RNA sequencing (RNA-seq) and network pharmacology analysis were conducted and the overlapping data were used to predict the mechanism of FZD, followed by verification with qPCR and Western blot assays. Finally, a retrospective analysis was performed to confirm FZD's efficacy and safety in OA patients.

RESULTS

The UPLC/MS/MS result showed that FZD contained atractylenolide I, benzoylhypaconitine, benzoylmesaconitine, benzoylaconitine, hypaconitine, mesaconitine, aconitine, lobetyolin, paeoniflorin, and pachymic acid. The in vivo data showed that FZD restored the cartilage degeneration in MIA-induced OA rats by ameliorating pain behavior parameters, recovering histopathological alterations, benefitting cartilage anabolism (up-regulating Col2 expression), and suppressing catabolism (down-regulating MMP13 and Col10 expressions). The in vitro data showed that FZD increased cell viability and wound healing capacity of chondrocytes, and restored the altered expressions of anabolic and catabolic genes of chondrocytes. The overlapping results of RNA-seq and network pharmacology analysis suggested that PI3K/Akt signaling mediated the anti-OA mechanism of FZD, which was verified by qPCR and Western blot experiments. Clinically, the anti-OA efficacy and safety of FZD were confirmed by the retrospective analysis on OA patients.

CONCLUSION

The scientific innovation of this study was the determination of anti-OA efficacy of FZD by experimental and clinical evidence and the discovery of its mechanism by integrated RNA-seq, network pharmacology, and molecular experiments, which suggests FZD as a promising TCM agency for OA treatment.

Baicalin promotes chondrocyte viability and the synthesis of extracellular matrix through TGF-β/Smad3 pathway in chondrocytes

BACKGROUND

Osteoarthritis (OA) is common in the elderly. Baicalin (BA) is a flavonoid monomer extracted from Scutellaria baicalensis Georgi, which has been reported to have anti-inflammatory, anti-deformation and anti-bacterial effects.

METHODS

Cultures of micromass and 3D alginate beads, Alcian blue and Safranin O (SO)/fast green staining were used to investigate chondrocyte viability and extracellular matrix (ECM) synthesis in chondrocytes of all groups. The expression of SOX9, Smad3, Aggrecan (ACAN), type II collagen (Col2α), matrix metallopetidase 9 (MMP9), MMP13 and ADAMTS5 in chondrocytes of all groups were detected by western blot or qRT-PCR.

RESULTS

The present study demonstrates that BA neutralized the IL-1β-induced downregulation of chondrocyte viability and ECM secretion, including ACAN and Col2α. The downregulation of SOX9, and the upregulation of MMP9, MMP13 and ADAMTS5 induced by IL-1β were reversed by BA treatment. Moreover, BA increased the nuclear translocation of Smad3 and SOX9 in chondrocytes cultured by micromass and 3D alginate beads. Interestingly, Smad3 inhibitor SIS3 reversed the promoting effect of BA on chondrocyte viability, ECM secretion, SOX9 and Smad3 nuclear translocation, and the inhibiting effect of BA on MMP9 and ADAMTS5 expressions. BA treatment also attenuated the decrease of Smad3 phosphorylation, SOX9 expression and the damage of cartilage integrity in mice which were induced by destabilization of the medial meniscus (DMM).

CONCLUSION

BA promotes chondrocyte viability and the cell matrix synthesis through TGF-β/Smad3 pathway in IL-1β-treated chondrocytes and DMM treated mice. BA is a potential therapeutic target for OA.

Establishing SW1353 Chondrocytes as a Cellular Model of Chondrolysis

Osteoarthritis (OA) is the most common degenerative joint disease characterised by chondrocyte cell death. An in vitro model of chondrocyte cell death may facilitate drug discovery in OA management. In this study, the cytotoxicity and mode of cell death of SW1353 chondrocytes treated with 24 h of OA inducers, including interleukin-1β (IL-1β), hydrogen peroxide (H2O2) and monosodium iodoacetate (MIA), were investigated. The microscopic features, oxidative (isoprostane) and inflammatory markers (tumour necrosis factor-alpha; TNF-α) for control and treated cells were compared. Our results showed that 24 h of H2O2 and MIA caused oxidative stress and a concentration-dependent reduction of SW1353 cell viability without TNF-α level upregulation. H2O2 primarily induced chondrocyte apoptosis with the detection of blebbing formation, cell shrinkage and cellular debris. MIA induced S-phase arrest on chondrocytes with a reduced number of attached cells but without significant cell death. On the other hand, 24 h of IL-1β did not affect the cell morphology and viability of SW1353 cells, with a significant increase in intracellular TNF-α levels without inducing oxidative stress. In conclusion, each OA inducer exerts differential effects on SW1353 chondrocyte cell fate. IL-1β is suitable in the inflammatory study but not for chondrocyte cell death. H2O2 and MIA are suitable for inducing chondrocyte cell death and growth arrest, respectively.

CircCDK14 protects against Osteoarthritis by sponging miR-125a-5p and promoting the expression of Smad2

Rationale: Osteoarthritis (OA) is the most common joint disease worldwide. Previous studies have identified the imbalance between extracellular matrix (ECM) catabolism and anabolism in cartilage tissue as the main cause. To date, there is no cure for OA despite a few symptomatic treatments. This study aimed to investigate the role of CircCDK14, a novel circRNA factor, in the progression of OA, and to elucidate its underlying molecular mechanisms.

Methods: The function of CircCDK14 in OA, as well as the interaction between CircCDK14 and its downstream target (miR-125a-5p) and mRNA target (Smad2), was evaluated by western blot (WB), immunofluorescence (IF), RNA immunoprecipitation (RIP), quantitative RT-PCR, luciferase assay and fluorescence in situ hybridization (FISH). Rabbit models were introduced to examine the function and mechanism of CircCDK14 in OA in vivo.

Results: In our present study, we found that CircCDK14, while being down-regulated in the joint wearing position, regulated metabolism, inhibited apoptosis and promoted proliferation in the cartilage. Mechanically, the protective effect of CircCDK14 was mediated by miR-125a-5p sponging, which downregulated the Smad2 expression and led to the dysfunction of TGF-β signaling pathway. Intra-articular injection of adeno-associated virus-CircCDK14 also alleviated OA in the rabbit model.

Conclusion: Our study revealed an important role of CircCDK14/miR-125a-5p/Smad2 axis in OA progression and provided a potential molecular therapeutic strategy for the treatment of OA.

Mummy Prevents IL-1β-Induced Inflammatory Responses and Cartilage Matrix Degradation via Inhibition of NF-қB Subunits Gene Expression in Pellet Culture System

Purpose: In Persian traditional medicine, application of Mummy material has been advised since hundred years ago for treatment of different diseases as bone fracture, cutaneous wounds and joint inflammation. Regarding to the claim of indigenous people for application of this material in the treatment of joint inflammation, the present study was designed to evaluate whether Mummy can revoke the inflammatory responses in chondrocytes stimulated with interleukin 1-β (IL-1β).

Methods: Isolated chondrocytes at the second passage were plated in 50 ml conical tubes at density of 1x10⁶ for pellet culture or were plated in T75 culture flasks as monolayer. Cells in both groups were treated as control (receiving serum free culture medium), negative control (receiving IL-1β (10ng/ml for 24 hr)) and IL-1β pre-stimulated cells which treated with Mummy at concentrations of 500 and 1000µg/ml for 72hrs. After 72 hrs, to evaluate whether Mummy can revoke the inflammatory response in chondrocytes, cell in different groups were prepared for investigation of gene expression profile of collagen II, Cox-2, MMP-13, C-Rel and P65 using real-time RT-PCR.

Results: Treatment of chondrocytes with IL-1β (10ng/ml) resulted in a significant increase in expression level of Cox-2, MMP-13, C-Rel and P65 in pellet culture system, while treatment of IL-1β-stimulated choncrocytes with Mummy at both concentrations of 500 and 1000µg/ml inhibited the expression level of above mentioned genes. Compared to the pellet culture, Mummy did not affect expression level of genes in monolayer condition.

Conclusion: The obtained data from this investigation revealed that Mummy can be used as a potent factor for inhibiting the inflammatory responses induced by IL-1β in chondrocytes probably through inhibition of NF-қB subunits activation.

Insights into the Action Mechanisms of Traditional Chinese Medicine in Osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by articular cartilage destruction, synovial inflammation, and osteophyte formation. No effective treatments are available. The current pharmacological medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics, accompanied by possible adverse effects, might ameliorate OA symptoms. But they do not arrest the progression of OA. Traditional Chinese medicine (TCM) provides medical value by modification of disease and symptoms in OA. Valuable work on exploring TCM merits for OA patients has been investigated using modern technologies, although the complicated interacting network among the numerous components indicates the uncertainty of target specification. This review will provide an overview of the action mechanism of TCM in the last 5 years, discussing the TCM activities of anti-inflammation, antiapoptosis, antioxidation, anticatabolism, and proliferation in OA. TCM is a proposed medical option for OA treatment.