Mechanisms of TGFβ3 Action as a Therapeutic Agent for Promoting the Synthesis of Extracellular Matrix Proteins in Hyaline Cartilage

Enhanced effects of slowly co-released TGF-β3 and BMP-2 from biomimetic calcium phosphate-coated silk fibroin scaffolds in the repair of osteochondral defects

Bioactive agents have demonstrated regenerative potential for cell-free bone tissue engineering. Nevertheless, certain challenges persist, including ineffective delivery methods and confined therapeutic potency. Here, we demonstrated that the biomimetic calcium phosphate coating system (BioCaP) could effectively uptake and slowly release the incorporated bioactive agents compared to the surface absorption system via osteoclast-mediated degradation of BioCaP coatings. The release kinetics were determined as a function of time. The release rate was stable without remarkable burst release during the first 1 day, followed by a sustained release from day 7 to day 19. Then, we developed the bi-functional BioCaP-coated silk fibroin scaffolds enabling the effective co-delivery of TGF-β3 and BMP-2 (SFI-T/SFI-B) and the corresponding slow release of TGF-β3 and BMP-2 exhibited superior potential in promoting chondrogenesis and osteogenesis without impairing cell vitality in vitro. The SFI-T/SFI-B scaffolds could improve cartilage and bone regeneration in 5 × 4 mm rabbit osteochondral (OC) defect. These findings indicate that the biomimetic calcium-phosphate coated silk fibroin scaffolds with slowly co-released TGF-β3 and BMP-2 effectively promote the repair of OC defects, hence facilitating the future clinical translation of controlled drug delivery in tissue engineering.

In Vitro Chondrogenic Differentiation of Human Adipose-Derived Stem Cells by Diacerein

Background

Tissue engineering is the application system that tries to restore damaged tissues by different approaches, such as cellular therapy, application of cell differential factors, and various materials. One of the important goals in tissue engineering is to guide stem cells directly to the desired tissue, and researchers tried to utilize different molecules as effective factors to improve this technique.

Objectives

This study aims to demonstrate the effects of diacerein, a slow-acting drug for the treatment of osteoarthritis, on mesenchymal stem cell proliferation and evaluate its potential in the chondrogenesis process.

Methods

Stem cells were isolated from adipose tissue, characterized by flow cytometry, and cells were treated with 10-5M diacerein for three weeks. Chondrogenic gene expression of SOX9, COL2A1, ACAN, and TGFB1 were analyzed by qRT-PCR and immunocytochemistry techniques.

Results

Our results showed that diacerein increased the expression of the following genes involved in chondrogenesis: SOX9 (2.9-fold, P < 0.00), COL2A1 (2.2-fold, P < 0.00), ACAN (2.7-fold, P < 0.00), and TGFB1 (2.6-fold, P < 0.00). Immunocytochemistry results also showed increased production of collagen type II as the main protein marker for chondrocytes.

Conclusions

We observed that diacerein alone could initiate and enhance chondrogenesis, and it can be used as a differentiation factor for stem cells to chondrocyte besides its ability to inhibit IL-1β. Knowing the actual function of diacerein, it could be a good candidate for the treatment of osteoarthritis.

Single-Cell RNA Sequencing of the Nucleus Pulposus Reveals Chondrocyte Differentiation and Regulation in Intervertebral Disc Degeneration

The nucleus pulposus (NP), a heterogeneous tissue, is an essential functional component of the intervertebral disc. However, NP cell development route and regulation mechanism in intervertebral disc degeneration (IVDD) remain unknown. Here, we performed single-cell RNA sequencing of six NP samples with normal control, mild degeneration, and severe degeneration. Based on unbiased clustering of gene expression patterns from 30,300 single-cell RNA sequencing, we identified three cell lineage families of macrophages, endothelial, and chondrocyte cells and characterized seven chondrocyte subtypes, and defined two developmental pathways of the chondrocyte cell lineage families in the process of IVDD. Additionally, CellPhoneDB analysis revealed potential interactions between chondrocyte cells and other cells in IVDD. Chondrocytes in one of the differentiated orientations interact with macrophages and endothelial cells and have an inflammatory amplification effect, which were key factors causing IVDD. Collectively, these results revealed the dynamic cell landscape of IVDD development and offered new insights into the influence of NP cells differentiation on extracellular matrix homeostasis during degeneration, providing potential treatment targets for IVDD.

Ear reconstruction research using animal models: The effect of fat grafting on costal cartilage stents

OBJECT

For congenital microtia patients with a depressed mastoid area, it is unclear whether autologous fat grafting to fill the depressed area of the cheek will affect the survival of the subsequent grafted costal cartilage stent. An animal model was used for in vivo research to provide guidance for clinical applications.

METHODS

Autologous costal cartilage was implanted in nude mice. Fat samples were collected at different time points and histological examination performed to analyze the activity of chondrocytes and the deposition of the chondrocyte matrix.

RESULTS

This nude mouse fat transplantation model study showed that there were statistical differences in chondrocyte viability between the fat filling group and the control group, but there was no statistical difference in the effect on collagen content.

CONCLUSION

Transplanting fat reduces the viability of chondrocytes, but has little effect on collagen matrix deposition.

Circ_0022382 ameliorated intervertebral disc degeneration by regulating TGF-β3 expression through sponge adsorption of miR-4726-5p

Circular RNAs (circRNAs) participate in the progression of many diseases, but knowledge on the role of circRNAs in intervertebral disc degeneration (IDD) is limited. In this study, we discovered the characteristics of a new circRNA (circ_0022382) in human endplate chondrocytes. Currently, real-time quantitative polymerase chain reaction (RT-qPCR) showed that the relative expression level of circ_0022382 was significantly lower under intermittent cyclic tension stimulation than in the control group. circ_0022382, miR-4726-5p and Transforming growth factor 3 (TGF-β3) were evaluated by RT-qPCR, Western Blot and immunofluorescence assay. Additionally, the role and mechanism of circ_0022382 in vivo were also consistent in the rat model. Furthermore, Intermittent cyclic mechanical tension can cause degeneration of endplate chondrocytes. The tension-sensitive circRNA_0022382 was decreased, and we found that circRNA_0022382 promoted morphology of endplate chondrocytes by sponge-binding miR-4726-5p down-regulation of target gene the TGF-β3 expression, thereby alleviating IDD. In a rat model of acupuncture, intervertebral disc injection of circ_0022382 relieved the progression of IDD in vivo. In conclusion, the circ_0022382/miR-4726-5p/TGF-β3 axis plays a key role in the anabolism and catabolism of the endplate chondrocyte extracellular matrix (ECM). It is suggested that circ_0022382 may provide a new approach for the prevention and treatment of IDD.

Methods of Modification of Mesenchymal Stem Cells and Conditions of Their Culturing for Hyaline Cartilage Tissue Engineering

The use of mesenchymal stromal cells (MSCs) for tissue engineering of hyaline cartilage is a topical area of regenerative medicine that has already entered clinical practice. The key stage of this procedure is to create conditions for chondrogenic differentiation of MSCs, increase the synthesis of hyaline cartilage extracellular matrix proteins by these cells and activate their proliferation. The first such works consisted in the indirect modification of cells, namely, in changing the conditions in which they are located, including microfracturing of the subchondral bone and the use of 3D biodegradable scaffolds. The most effective methods for modifying the cell culture of MSCs are protein and physical, which have already been partially introduced into clinical practice. Genetic methods for modifying MSCs, despite their effectiveness, have significant limitations. Techniques have not yet been developed that allow studying the effectiveness of their application even in limited groups of patients. The use of MSC modification methods allows precise regulation of cell culture proliferation, and in combination with the use of a 3D biodegradable scaffold, it allows obtaining a hyaline-like regenerate in the damaged area. This review is devoted to the consideration and comparison of various methods used to modify the cell culture of MSCs for their use in regenerative medicine of cartilage tissue.

Specificities of Scanning Electron Microscopy and Histological Methods in Assessing Cell-Engineered Construct Effectiveness for the Recovery of Hyaline Cartilage

Damage to the hyaline layer of the articular surface is an urgent problem for millions of people around the world. At present, a large number of experimental methods are being developed to address this problem, including the transplantation of a cell-engineered construct (CEC) composed of a biodegradable scaffold with a premixed cell culture into the damaged area of the articular surface. However, current methods for analyzing the effectiveness of such CECs have significant limitations. This study aimed to compare the SEM technique, classical histology, and cryosectioning for the analysis of CECs transplanted to hyaline cartilage.