Ganglioside GM3 Up-Regulate Chondrogenic Differentiation by Transform Growth Factor Receptors

Glycosphingolipids in Osteoarthritis and Cartilage-Regeneration Therapy: Mechanisms and Therapeutic Prospects Based on a Narrative Review of the Literature

Glycosphingolipids (GSLs), a subtype of glycolipids containing sphingosine, are critical components of vertebrate plasma membranes, playing a pivotal role in cellular signaling and interactions. In human articular cartilage in osteoarthritis (OA), GSL expression is known notably to decrease. This review focuses on the roles of gangliosides, a specific type of GSL, in cartilage degeneration and regeneration, emphasizing their regulatory function in signal transduction. The expression of gangliosides, whether endogenous or augmented exogenously, is regulated at the enzymatic level, targeting specific glycosyltransferases. This regulation has significant implications for the composition of cell-surface gangliosides and their impact on signal transduction in chondrocytes and progenitor cells. Different levels of ganglioside expression can influence signaling pathways in various ways, potentially affecting cell properties, including malignancy. Moreover, gene manipulations against gangliosides have been shown to regulate cartilage metabolisms and chondrocyte differentiation in vivo and in vitro. This review highlights the potential of targeting gangliosides in the development of therapeutic strategies for osteoarthritis and cartilage injury and addresses promising directions for future research and treatment.

Lipid rafts mediate multilineage differentiation of human dental pulp-derived stem cells (DPSCs)

Cell outer membranes contain glycosphingolipids and protein receptors, which are integrated into glycoprotein domains, known as lipid rafts, which are involved in a variety of cellular processes, including receptor-mediated signal transduction and cellular differentiation process. In this study, we analyzed the lipidic composition of human Dental Pulp-Derived Stem Cells (DPSCs), and the role of lipid rafts during the multilineage differentiation process. The relative quantification of lipid metabolites in the organic fraction of DPSCs, performed by Nuclear Magnetic Resonance (NMR) spectroscopy, showed that mono-unsaturated fatty acids (MUFAs) were the most representative species in the total pool of acyl chains, compared to polyunsatured fatty acids (PUFAs). In addition, the stimulation of DPSCs with different culture media induces a multilineage differentiation process, determining changes in the gangliosides pattern. To understand the functional role of lipid rafts during multilineage differentiation, DPSCs were pretreated with a typical lipid raft affecting agent (MβCD). Subsequently, DPSCs were inducted to differentiate into osteoblast, chondroblast and adipoblast cells with specific media. We observed that raft-affecting agent MβCD prevented AKT activation and the expression of lineage-specific mRNA such as OSX, PPARγ2, and SOX9 during multilineage differentiation. Moreover, this compound significantly prevented the tri-lineage differentiation induced by specific stimuli, indicating that lipid raft integrity is essential for DPSCs differentiation. These results suggest that lipid rafts alteration may affect the signaling pathway activated, preventing multilineage differentiation.

Extracellular matrix-induced signaling pathways in mesenchymal stem/stromal cells

The extracellular matrix (ECM) is a crucial component of the stem cell microenvironment, or stem-cell niches, and contributes to the regulation of cell behavior and fate. Accumulating evidence indicates that different types of stem cells possess a large variety of molecules responsible for interactions with the ECM, mediating specific epigenetic rearrangements and corresponding changes in transcriptome profile. Signals from the ECM are crucial at all stages of ontogenesis, including embryonic and postnatal development, as well as tissue renewal and repair. The ECM could regulate stem cell transition from a quiescent state to readiness to perceive the signals of differentiation induction (competence) and the transition between different stages of differentiation (commitment). Currently, to unveil the complex networks of cellular signaling from the ECM, multiple approaches including screening methods, the analysis of the cell matrixome, and the creation of predictive networks of protein-protein interactions based on experimental data are used. In this review, we consider the existing evidence regarded the contribution of ECM-induced intracellular signaling pathways into the regulation of stem cell differentiation focusing on mesenchymal stem/stromal cells (MSCs) as well-studied type of postnatal stem cells totally depended on signals from ECM. Furthermore, we propose a system biology-based approach for the prediction of ECM-mediated signal transduction pathways in target cells. Video Abstract.

Immunogenicity of mesenchymal stromal/stem cells

Mesenchymal stromal/stem cells (MSCs) possess the ability to self-renew and differentiate into other cell types. Because of their anti-inflammatory and immunomodulatory abilities, as well as their more ready availability compared to other stem cell sources, MSCs hold great promise for the treatment of many diseases, such as haematological defects, acute respiratory distress syndrome, autoimmunity, cardiovascular diseases, etc. However, immune rejection remains an important problem. MSCs are considered to have low immunogenicity, but they do not have full immunological privilege. This review analyzes and discusses the safety of MSCs from the perspective of their immunogenicity, with the aim of providing a reference for future research and clinical application.

Gangliosides and Their Role in Multilineage Differentiation of Mesenchymal Stem Cells

Gangliosides (GGs) are a glycolipid class present on Mesenchymal Stem Cells (MSCs) surfaces with a critical appearance role in stem cell differentiation, even though their mechanistic role in signaling and differentiation remains largely unknown. This review aims to carry out a critical analysis of the predictive role of gangliosides as specific markers of the cellular state of undifferentiated and differentiated MSCs, towards the osteogenic, chondrogenic, neurogenic, and adipogenic lineage. For this reason, we analyzed the role of GGs during multilineage differentiation processes of several types of MSCs such as Umbilical Cord-derived MSCs (UC-MSCs), Bone Marrow-derived MSCs (BM-MSCs), Dental Pulp derived MSCs (DPSCs), and Adipose derived MSCs (ADSCs). Moreover, we examined the possible role of GGs as specific cell surface markers to identify or isolate specific stem cell isotypes and their potential use as additional markers for quality control of cell-based therapies.

Alterations of Glycosphingolipid Glycans and Chondrogenic Markers during Differentiation of Human Induced Pluripotent Stem Cells into Chondrocytes

Due to the limited intrinsic healing potential of cartilage, injury to this tissue may lead to osteoarthritis. Human induced pluripotent stem cells (iPSCs), which can be differentiated into chondrocytes, are a promising source of cells for cartilage regenerative therapy. Currently, however, the methods for evaluating chondrogenic differentiation of iPSCs are very limited; the main techniques are based on the detection of chondrogenic genes and histological analysis of the extracellular matrix. The cell surface is coated with glycocalyx, a layer of glycoconjugates including glycosphingolipids (GSLs) and glycoproteins. The glycans in glycoconjugates play important roles in biological events, and their expression and structure vary widely depending on cell types and conditions. In this study, we performed a quantitative GSL-glycan analysis of human iPSCs, iPSC-derived mesenchymal stem cell like cells (iPS-MSC like cells), iPS-MSC-derived chondrocytes (iPS-MSC-CDs), bone marrow-derived mesenchymal stem cells (BMSCs), and BMSC-derived chondrocytes (BMSC-CDs) using glycoblotting technology. We found that GSL-glycan profiles differed among cell types, and that the GSL-glycome underwent a characteristic alteration during the process of chondrogenic differentiation. Furthermore, we analyzed the GSL-glycome of normal human cartilage and found that it was quite similar to that of iPS-MSC-CDs. This is the first study to evaluate GSL-glycan structures on human iPS-derived cartilaginous particles under micromass culture conditions and those of normal human cartilage. Our results indicate that GSL-glycome analysis is useful for evaluating target cell differentiation and can thus support safe regenerative medicine.

Application of Mesenchymal Stem Cells in Inflammatory and Fibrotic Diseases

Mesenchymal stem cells (MSCs) are multipotent stem cells that can be isolated from various tissues in the adult body. MSCs should be characterized by three criteria for regenerative medicine. MSCs must (1) adhere to plastic surfaces, (2) express specific surface antigens, and (3) differentiate into mesodermal lineages, including chondrocytes, osteoblasts, and adipocytes, in vitro. Interestingly, MSCs have immunomodulatory features and secrete trophic factors and immune receptors that regulate the microenvironment in host tissue. These specific and unique therapeutic properties make MSCs ideal as therapeutic agents in vivo. Specifically, pre-clinical and clinical investigators generated inflammatory and fibrotic diseases models, and then transplantation of MSCs into diseases models for therapeutic effects investigation. In this review, we characterize MSCs from various tissues and describe their applications for treating various inflammation and fibrotic diseases.