Comparison between articular chondrocytes and mesenchymal stromal cells for the production of articular cartilage implants.

Focal lesions of articular cartilage give rise to pain and reduced joint function and may, if left untreated, lead to osteoarthritis. Implantation of generated, scaffold-free autologous cartilage discs may represent the best treatment option. Here we compare articular chondrocytes (ACs) and bone marrow-derived mesenchymal stromal cells (MSCs) for their ability to make scaffold-free cartilage discs.

MicroRNAs mediated regulation of glutathione peroxidase 7 expression and its changes during adipogenesis.

Glutathione peroxidase 7 (GPx7) acts as an intracellular stress sensor/transmitter and plays an important role in adipocyte differentiation and the prevention of obesity related pathologies. For this reason, finding the regulatory mechanisms that control GPx7 expression is of great importance. As microRNAs (miRNAs) could participate in the regulation of GPx7 expression, we studied the inhibition of GPx7 expression by four selected miRNAs with relation to obesity and adipogenesis.

Extensive downregulation of immune gene expression by microRNA-140-3p 5' isomiR in an in vitro model of osteoarthritis.

Objective: MicroRNA-140-3p is the most prevalent form of canonical miR-140 in native chondrocytes. IsomiRs are sequence variants of microRNAs with potentially distinct functionalities. Here we present functional studies of canonical microRNA-140-3p and two of its most prevalent isomiRs, a 5' isomiR and a 3' isomiR, in an inflammation-induced model of osteoarthritis (OA).

Scaffold-Free Engineering of Human Cartilage Implants.

Objective: Despite new strategies in tissue engineering, cartilage repair remains a major challenge. Our aim is to treat patients with focal lesions of articular cartilage with autologous hyaline cartilage implants using a scaffold-free approach. In this article, we describe experiments to optimize production of scaffold-free cartilage discs.

Robust profiling of microRNAs and isomiRs in human plasma exosomes across 46 individuals.

microRNAs (miRNAs) are small double stranded RNA molecules consisting of two complementary strands called the 5p and 3p arms. Following imprecise processing and/or addition of nucleotides at the ends, miRNA biogenesis can give rise to variants called isomiRs. Exosomes are small vesicles released by cells.

Evaluating plasma extracellular vesicle microRNAs as possible biomarkers for osteoarthritis.

Objective: MicroRNAs (miRNAs) are being launched as biomarkers for various diseases, but a robust biomarker for articular cartilage pathology has yet to be discovered. Here we evaluate plasma extracellular vesicle (EV) miRNAs as possible biomarkers for osteoarthritis (OA).

Method: We compared miRNA levels found in plasma EVs from patients with OA with controls without OA using next generation sequencing (NGS) technique.

Impact of humanised isolation and culture conditions on stemness and osteogenic potential of bone marrow derived mesenchymal stromal cells.

Therapeutic potential of human bone marrow stromal/stem cells (hBMSC) must be developed using well defined xenogenic-free conditions. hBMSC were isolated from healthy donors (n = 3) using different isolation and expansion methods. Donor I was isolated and expanded by either bone marrow directly seeded and cells expanded in 10% AB human serum (AB) +5 ng/ml fibroblast growth factor-2 (FGF2) [Direct(AB + FGF)] or Ammonium-Chloride-Potassium Lysing Buffer was used before the cells were expanded in 10% AB +5 ng/ml FGF-2 [ACK(AB + FGF)] or Lymphoprep density gradient medium was used before the cells were expanded in 10% AB +5 ng/ml FGF2 [Lympho(AB + FGF] or bone marrow directly seeded and cells expanded in 10% pooled platelet lysate plasma (PL) + heparin (2 I/U/mL) [Direct(PL)].

Interstitial cells in calcified aortic valves have reduced differentiation potential and stem cell-like properties.

Valve interstitial cells (VICs) are crucial in the development of calcific aortic valve disease. The purpose of the present investigation was to compare the phenotype, differentiation potential and stem cell-like properties of cells from calcified and healthy aortic valves. VICs were isolated from human healthy and calcified aortic valves.

Multi-pathway Protective Effects of MicroRNAs on Human Chondrocytes in an In Vitro Model of Osteoarthritis.

Osteoarthritis (OA) is the most common degenerative joint disease. One of the main pathogenic factors of OA is thought to be inflammation. Other factors associated with OA are dysregulation of microRNAs, reduced autophagic activity, oxidative stress, and altered metabolism.

3D bioprinting of hydrogel constructs with cell and material gradients for the regeneration of full-thickness chondral defect using a microfluidic printing head.

Osteochondral (OC) tissue is a biphasic material comprised of articular cartilage integrated atop subchondral bone. Damage to this tissue is highly problematic, owing to its intrinsic inability to regenerate functional tissue in response to trauma or disease. Further, the function of the tissue is largely conferred by its compartmentalized zonal microstructure and composition.

Single-Cell RNA Sequencing of Expanded Chondrocytes: MSC-Like Cells With No Evidence of Distinct Subsets.

Objective: To investigate the heterogeneity of expanded chondrocytes used for autologous chondrocyte implantation.

Methods: Human articular chondrocytes were expanded for 14 days, sorted into 86 single cells using fluorescence-activated cell sorting and subjected to single-cell RNA sequencing. Principal component, Cross hierarchical clustering, and differential gene expression analyses were used for data evaluation.

Expression of inflammatory cytokines in mesenchymal stromal cells is sensitive to culture conditions and simple cell manipulations.

Background: Mesenchymal stromal cells (MSCs) can be used in several clinical applications. While MSCs are frequently cultured in fetal bovine serum for in vitro experimentation, human serum supplements are required for cells to be used in patients. Here we show how different human serum supplements and in vitro manipulations used during the cell culture impact on MSC proliferation rate and expression of inflammatory molecules.

microRNA-140 Inhibits Inflammation and Stimulates Chondrogenesis in a Model of Interleukin 1β-induced Osteoarthritis.

Osteoarthritis is a serious disease of articular cartilage. The pathogenic factors contributing to this disorder are inflammation, extracellular matrix degradation and failure to rebuild the articular cartilage. Preclinical studies suggest that microRNA-140 may play a protective role in osteoarthritis development, but little is known about the mechanism by which this occurs.

microRNA-140 targets RALA and regulates chondrogenic differentiation of human mesenchymal stem cells by translational enhancement of SOX9 and ACAN.

Lesions of articular cartilage do not heal spontaneously. One treatment strategy would be to make cartilage in the laboratory by directed chondrogenic differentiation of mesenchymal stem cells (MSCs). To promote our understanding of the molecular control of chondrogenesis, we have compared the changes in microRNAs (miRNAs) during in vitro chondrogenesis of MSCs with those observed in uncultured and dedifferentiated articular chondrocytes (ACs).

Similar properties of chondrocytes from osteoarthritis joints and mesenchymal stem cells from healthy donors for tissue engineering of articular cartilage.

Lesions of hyaline cartilage do not heal spontaneously, and represent a therapeutic challenge. In vitro engineering of articular cartilage using cells and biomaterials may prove to be the best solution. Patients with osteoarthritis (OA) may require tissue engineered cartilage therapy.

Liposome delivery of microRNA-145 to mesenchymal stem cells leads to immunological off-target effects mediated by RIG-I.

Synthetic microRNAs regulate gene expression when transfected into cells, and may be used in strategies for molecular therapy both in vitro and in vivo. Liposomal transfection reagents are frequently used as delivery vehicles in both settings. Here, we report on the immunological off-target effects observed following liposome transfection of synthetic microRNA-145 into human mesenchymal stem cells and human articular chondrocytes (hAC).

Effect of three-dimensional culture and incubator gas concentration on phenotype and differentiation capability of human mesenchymal stem cells.

To obtain sufficient numbers of cells for tissue engineering applications, human bone marrow-derived mesenchymal stem cells (hBM-MSC) are commonly cultured as monolayers in incubators containing room air. In this study, we investigated whether three-dimensional (3D) culture conditions and incubator gas concentrations more similar to those observed in vivo impacted on cell expansion, differentiation capability, or phenotype of hBM-MSC. We found that 3D culture alone increased the expression of some molecules involved in osteogenic and adipogenic differentiation.

Human primary articular chondrocytes, chondroblasts-like cells, and dedifferentiated chondrocytes: differences in gene, microRNA, and protein expression and phenotype.

In this study we have isolated human primary uncultured articular chondrocytes. When these cells are allowed to proliferate within their own extracellular matrix (ECM), they begin to produce hyaline ECM molecules similar to embryological chondroblasts. These cells are called chondroblast-like cells.