Decorin knockdown affects the gene expression profile of adhesion, growth and extracellular matrix metabolism in C-28/I2 chondrocytes

Knockdown of decorin in human bone marrow mesenchymal stem cells suppresses proteoglycan layer formation and establishes a pro-inflammatory environment on titanium oxide surfaces

Osseointegration is essential for successful implant treatment. However, the underlying molecular mechanisms remain unclear. In this study, we focused on decorin (DCN), which was hypothesized to be present in the proteoglycan (PG) layer at the interface between bone and the titanium oxide (TiOx) surface. We utilized DCN RNA interference in human bone marrow mesenchymal stem cells (hBMSCs) to investigate its effects on PG layer formation, proliferation, initial adhesion, cell extension, osteogenic capacity, fibrotic markers, and immunotolerance to TiOx in vitro. After 14 days of cultivation, we observed no PG layer was detected, and the osteogenic capacity was suppressed in DCN-depleted hBMSCs. Furthermore, the conditioned medium upregulated the expression of M1 macrophage markers in human macrophages. These results suggest that endogenous DCN plays a crucial role in PG layer formation and that the PG layer alters inflammation around Ti materials.

Active Targets and Potential Mechanisms of Erhuang Quzhi Formula in Treating NAFLD: Network Analysis and Experimental Assessment

The purpose of this research was to investigate the main active components, potential targets of action, and pharmacological mechanisms of Erhuang Quzhi Formula (EHQZF) against NAFLD using network pharmacology, molecular docking, and experimental validation. The main active chemical components of EHQZF and the potential targets for treating NAFLD were extracted and analyzed. The PPI network diagram of "Traditional Chinese Medicine-Active Ingredients-Core Targets" was constructed and the GO, KEGG, and molecular docking analysis were carried out. Identification of components in traditional Chinese medicine compounds was conducted by LC-MS. NAFLD models were established and relevant pathologic indicators and Western blot were analyzed in vivo and ex vivo. Totally 8 herbs attributed to the liver meridian and 20 corresponding targets of NAFLD were obtained from EHQZF. Flavonoids and phenolic acids as the main components of EHQZF treated NAFLD through the MAPK/AKT signaling pathway. Pathway enrichment analysis focused on the MAPK/AKT signaling pathway and apoptosis signaling pathway. Molecular docking showed that Quercetin and Luteolin had stable binding structures with AKT1, STAT3, and other targets. Experiments showed that EHQZF reduced lipid accumulation, regulated changes in adipose tissue, inhibited the MAPK/AKT signaling pathway and exert multiple components, several targets, and multiple pathway interactions to treat NAFLD.

Biomaterial Integration in the Joint: Pathological Considerations, Immunomodulation, and the Extracellular Matrix

Defects of articular joints are becoming an increasing societal burden due to a persistent increase in obesity and aging. For some patients suffering from cartilage erosion, joint replacement is the final option to regain proper motion and limit pain. Extensive research has been undertaken to identify novel strategies enabling earlier intervention to promote regeneration and cartilage healing. With the introduction of decellularized extracellular matrix (dECM), researchers have tapped into the potential for increased tissue regeneration by designing biomaterials with inherent biochemical and immunomodulatory signals. Compared to conventional and synthetic materials, dECM-based materials invoke a reduced foreign body response. It is therefore highly beneficial to understand the interplay of how these native tissue-based materials initiate a favorable remodeling process by the immune system. Yet, such an understanding also demands increasing considerations of the pathological environment and remodeling processes, especially for materials designed for early disease intervention. This knowledge would avoid rejection and help predict complications in conditions with inflammatory components such as arthritides. This review outlines general issues facing biomaterial integration and emphasizes the importance of tissue-derived macromolecular components in regulating essential homeostatic, immunological, and pathological processes to increase biomaterial integration for patients suffering from joint degenerative diseases. This article is protected by copyright. All rights reserved.

The role of tendon derived stem/progenitor cells and extracellular matrix components in the bone tendon junction repair

Fibrocartilage enthesis is the junction between bone and tendon with a typical characteristics of fibrocartilage transition zones. The regeneration of this transition zone is the bottleneck for functional restoration of bone tendon junction (BTJ). Biomimetic approaches, especially decellularized extracellular matrix (ECM) materials, are strategies which aim to mimic the components of tissues to the utmost extent, and are becoming popular in BTJ healing because of their ability not only to provide scaffolds to allow cells to attach and migrate, but also to provide a microenvironment to guide stem/progenitor cells lineage-specific differentiation. However, the cellular and molecular mechanisms of those approaches, especially the ECM proteins, remain unclear. For BTJ reconstruction, fibrocartilage regeneration is the key for good integrity of bone and tendon as well as its mechanical recovery, so the components which can guide stem cells to a chondrogenic commitment in biomimetic approaches might well be the key for fibrocartilage regeneration and eventually for the better BTJ healing. In this review, we firstly discuss the importance of cartilage-like formation in the healing process of BTJ. Next, we explore the possibility of tendon-derived stem/progenitor cells as cell sources for BTJ regeneration due to their multi-differentiation potential. Finally, we summarize the role of extracellular matrix components of BTJ in guiding stem cell fate to a chondrogenic commitment, so as to provide cues for understanding the mechanisms of lineage-specific potential of biomimetic approaches as well as to inspire researchers to incorporate unique ECM components that facilitate BTJ repair into design.