Dihydrocaffeic acid improves IL-1β-induced inflammation and cartilage degradation via inhibiting NF-κB and MAPK signalling pathways

Aims

Osteoarthritis (OA) is a prevalent joint disorder with inflammatory response and cartilage deterioration as its main features. Dihydrocaffeic acid (DHCA), a bioactive component extracted from natural plant (gynura bicolor), has demonstrated anti-inflammatory properties in various diseases. We aimed to explore the chondroprotective effect of DHCA on OA and its potential mechanism.

Methods

In vitro, interleukin-1 beta (IL-1β) was used to establish the mice OA chondrocytes. Cell counting kit-8 evaluated chondrocyte viability. Western blotting analyzed the expression levels of collagen II, aggrecan, SOX9, inducible nitric oxide synthase (iNOS), IL-6, matrix metalloproteinases (MMPs: MMP1, MMP3, and MMP13), and signalling molecules associated with nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. Immunofluorescence analysis assessed the expression of aggrecan, collagen II, MMP13, and p-P65. In vivo, a destabilized medial meniscus (DMM) surgery was used to induce mice OA knee joints. After injection of DHCA or a vehicle into the injured joints, histological staining gauged the severity of cartilage damage.

Results

DHCA prevented iNOS and IL-6 from being upregulated by IL-1β. Moreover, the IL-1β-induced upregulation of MMPs could be inhibited by DHCA. Additionally, the administration of DHCA counteracted IL-1β-induced downregulation of aggrecan, collagen II, and SOX9. DHCA protected articular cartilage by blocking the NF-κB and MAPK pathways. Furthermore, DHCA mitigated the destruction of articular cartilage in vivo.

Conclusion

We present evidence that DHCA alleviates inflammation and cartilage degradation in OA chondrocytes via suppressing the NF-κB and MAPK pathways, indicating that DHCA may be a potential agent for OA treatment.

Cite this article: Bone Joint Res 2023;12(4):259–273.

MicroRNA-4423-3p inhibits proliferation of fibroblast-like synoviocytes by targeting matrix metalloproteinase 13 in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that is increasing in incidence worldwide. RA is regulated by a variety of microRNAs (miRNAs/miR). Moreover, analysis of public data has revealed that miR-4423-3p is significantly downregulated in peripheral blood mononuclear cells of RA patients. This study investigated the role of miR-4423-3p in RA. The levels of miR-4423-3p and matrix metalloproteinase 13 (MMP13) in RA patients and the regulatory relationship between miR-4423-3p and MMP13 were analyzed using public data. A dual-luciferase reporter assay was performed to verify that miR-4423-3p targets MMP13 in human fibroblast-like synoviocyte (HFLS) RA cells (HFLS-RA). Following the overexpression of miR-4423-3p, miR-4423-3p inhibitor, and MMP13 in HFLS-RA, viability, proliferation, cell cycle, apoptosis, and invasion/migration assays were used to detect the effects of miR-4423-3p targeting MMP13 on cell biological processes. The results revealed that miR-4423-3p was downregulated in peripheral blood mononuclear cells of RA patients and MMP13 was upregulated in synovial tissue of RA patients. miR-4423-3p targets the 3' untranslated region of MMP13 and downregulates MMP13 expression. After overexpression of miR-4423-3p, cell proliferation, migration, and invasion were inhibited, the cell cycle was prevented and cell apoptosis was promoted. Overexpression of MMP13 promoted cell proliferation, migration, and invasion, while accelerating the cell cycle process and suppressing apoptosis. The findings indicate that in HFLS-RA cells, overexpression of miR-4423-3p inhibited proliferation, migration, and invasion, and promoted apoptosis by negatively regulating MMP13. The overexpression of miR-4423-3p might be a novel strategy for the treatment of RA.

Effects of Fibrotic Tissue on Liver-targeted Hydrodynamic Gene Delivery

Hydrodynamic gene delivery is a common method for gene transfer to the liver of small animals, and its clinical applicability in large animals has been demonstrated. Previous studies focused on functional analyses of therapeutic genes in animals with normal livers and little, however, is known regarding its effectiveness and safety in animals with liver fibrosis. Therefore, this study aimed to examine the effects of liver fibrosis on hydrodynamic gene delivery efficiency using a rat liver fibrosis model. We demonstrated for the first time, using pCMV-Luc plasmid, that this procedure is safe and that the amount of fibrotic tissue in the liver decreases gene delivery efficiency, resulting in decrease in luciferase activity depending on the volume of fibrotic tissue in the liver and the number of hepatocytes that are immunohistochemically stained positive for transgene product. We further demonstrate that antifibrotic gene therapy with matrix metalloproteinase-13 gene reduces liver fibrosis and improves efficiency of hydrodynamic gene delivery. These results demonstrate the negative effects of fibrotic tissue on hydrodynamic gene delivery and its recovery by appropriate antifibrotic therapy.

Effective Prevention of Liver Fibrosis by Liver-targeted Hydrodynamic Gene Delivery of Matrix Metalloproteinase-13 in a Rat Liver Fibrosis Model

Liver fibrosis is the final stage of liver diseases that lead to liver failure and cancer. While various diagnostic methods, including the use of serum marker, have been established, no standard therapy has been developed. The objective of this study was to assess the approach of overexpressing matrix metalloproteinase-13 gene (MMP13) in rat liver to prevent liver fibrosis progression. A rat liver fibrosis model was established by ligating the bile duct, followed by liver-targeted hydrodynamic gene delivery of a MMP13 expression vector, containing a CAG promoter-MMP13-IRES-tdTomato-polyA cassette. After 14 days, the serum level of MMP13 peaked at 71.7 pg/ml in MMP13-treated group, whereas the nontreated group only showed a level of ~5 pg/ml (P < 0.001). These levels were sustained for the next 60 days. The statistically lower level of the hyaluronic acids in treated group versus the nontreated group (P < 0.05) reveals the therapeutic effect of MMP13 overexpression. Quantitative analysis of tissue stained with sirius red showed a statistically larger volume of fibrotic tissue in the nontreated group compared to that of MMP13-treated rats (P < 0.05). These results suggest that the liver-targeted hydrodynamic delivery of MMP13 gene could be effective in the prevention of liver fibrosis.

Activation of β-catenin signalling leads to temporomandibular joint defects

Despite extensive research in knee and hip osteoarthritis (OA), the underlying mechanism of temporomandibular joint (TMJ) disorder remains largely unknown. The purpose of this study was to determine whether the constitutive activation of β-catenin in the middle and deep layers of the articular cartilage can compromise the homeostasis of this tissue in the TMJ. Col2CreERT2 transgenic mice were bred with RosamT/mG reporter mice to determine Cre recombination efficiency. Col2CreERT2 mice were then crossed with β-cateninflox(ex3)+ mice to generate β-catenin conditional activation mice, β-catenin(ex3)Col2ER. TMJ samples were harvested when the mice were 1-, 3- or 6-month-old and evaluated using histology, histomorphometry and immunohistochemistry. β-catenin(ex3)Col2ER mice were further crossed with Mmp13flox/flox and Adamts5-/- mice to generate (β-catenin(ex3)/Mmp13)Col2ER and β-catenin(ex3)Col2ER)/Adamts5-/- double mutant mice to investigate the role of Mmp13 and Adamts5 in the development of TMJ disorder. High levels of Cre-recombination were seen in Col2CreERT2;RosamT/mGmice. Progressive TMJ defects developed in 1-, 3- and 6-month-old β-catenin(ex3)Col2ER mice, as revealed by histology and histomorphometry. Results further demonstrated that the defects observed in β-catenin(ex3)Col2ER mice were significantly decelerated after deletion of the Mmp13 or Adamts5 gene in (β-catenin(ex3)/Mmp13)Col2ER or β-catenin(ex3)Col2ER/Adamts5-/- double mutant mice. In summary, we found that β-catenin is a critical gene in the induction of TMJ cartilage degeneration, and over-expressing β-catenin in TMJ cartilage leads to defects assembling an OA-like phenotype. Deletion of Mmp13 and Adamts5 in β-catenin(ex3)Col2ER mice ameliorates the development of TMJ defects. This study suggests that Mmp13 and Adamts5 could be potential therapeutic targets for the treatment of TMJ disorders.

Osterix regulates calcification and degradation of chondrogenic matrices through matrix metalloproteinase 13 (MMP13) expression in association with transcription factor Runx2 during endochondral ossification

Endochondral ossification is temporally and spatially regulated by several critical transcription factors, including Sox9, Runx2, and Runx3. Although the molecular mechanisms that control the late stages of endochondral ossification (e.g. calcification) are physiologically and pathologically important, these precise regulatory mechanisms remain unclear. Here, we demonstrate that Osterix is an essential transcription factor for endochondral ossification that functions downstream of Runx2. The global and conditional Osterix-deficient mice studied here exhibited a defect of cartilage-matrix ossification and matrix vesicle formation. Importantly, Osterix deficiencies caused the arrest of endochondral ossification at the hypertrophic stage. Microarray analysis revealed that matrix metallopeptidase 13 (MMP13) is an important target of Osterix. We also showed that there exists a physical interaction between Osterix and Runx2 and that these proteins function cooperatively to induce MMP13 during chondrocyte differentiation. Most interestingly, the introduction of MMP13 stimulated the calcification of matrices in Osterix-deficient mouse limb bud cells. Our results demonstrated that Osterix was essential to endochondral ossification and revealed that the physical and functional interaction between Osterix and Runx2 were necessary for the induction of MMP13 during endochondral ossification.