Mesenchymal stem cells: Molecular characteristics and clinical applications

Effective Bone Tissue Fabrication Using 3D-Printed Citrate-Based Nanocomposite Scaffolds Laden with BMP9-Stimulated Human Urine Stem Cells

Effective repair of large bone defects through bone tissue engineering (BTE) remains an unmet clinical challenge. Successful BTE requires optimal and synergistic interactions among biocompatible scaffolds, osteogenic factors, and osteoprogenitors to form a highly vascularized microenvironment for bone regeneration and osseointegration. We sought to develop a highly effective BTE system by using 3D printed citrate-based mPOC/hydroxyapatite (HA) composites laden with BMP9-stimulated human urine stem cells (USCs). Specifically, we synthesized and characterized methacrylate poly(1,8 octamethylene citrate) (mPOC), mixed it with 0%, 40% or 60% HA (i.e., mPOC-0HA, mPOC-40HA, or mPOC-60HA), and fabricated composite scaffold via micro-continuous liquid interface production (μCLIP). The 3D-printed mPOC-HA composite scaffolds were compatible with human USCs that exhibited high osteogenic activity in vitro upon BMP9 stimulation. Subcutaneous implantation of mPOC-HA scaffolds laden with BMP9-stimulated USCs revealed effective bone formation in all three types of mPOC-HA composite scaffolds. Histologic evaluation revealed that the mPOC-60HA composite scaffold yielded the most mature bone, resembling native bone tissue with extensive scaffold-osteointegration. Collectively, these findings demonstrate that the citrate-based mPOC-60HA composite, human urine stem cells, and the potent osteogenic factor BMP9 constitute a desirable triad for effective bone tissue engineering.

Evolution and Innovations in Bone Marrow Cellular Therapy for Musculoskeletal Disorders: Tracing the Historical Trajectory and Contemporary Advances

Bone marrow cellular therapy has undergone a remarkable evolution, significantly impacting the treatment of musculoskeletal disorders. This review traces the historical trajectory from early mythological references to contemporary scientific advancements. The groundbreaking work of Friedenstein in 1968, identifying fibroblast colony-forming cells in bone marrow, laid the foundation for future studies. Caplan's subsequent identification of mesenchymal stem cells (MSCs) in 1991 highlighted their differentiation potential and immunomodulatory properties, establishing them as key players in regenerative medicine. Contemporary research has focused on refining techniques for isolating and applying bone marrow-derived MSCs. These cells have shown promise in treating conditions like osteonecrosis, osteoarthritis, and tendon injuries thanks to their ability to promote tissue repair, modulate immune responses, and enhance angiogenesis. Clinical studies have demonstrated significant improvements in pain relief, functional recovery, and tissue regeneration. Innovations such as the ACH classification system and advancements in bone marrow aspiration methods have standardized practices, improving the consistency and efficacy of these therapies. Recent clinical trials have validated the therapeutic potential of bone marrow-derived products, highlighting their advantages in both surgical and non-surgical applications. Studies have shown that MSCs can reduce inflammation, support bone healing, and enhance cartilage repair. However, challenges remain, including the need for rigorous characterization of cell populations and standardized reporting in clinical trials. Addressing these issues is crucial for advancing the field and ensuring the reliable application of these therapies. Looking ahead, future research should focus on integrating bone marrow-derived products with other regenerative techniques and exploring non-surgical interventions. The continued innovation and refinement of these therapies hold promise for revolutionizing the treatment of musculoskeletal disorders, offering improved patient outcomes, and advancing the boundaries of medical science.

Exploring the Potential Effects of Cryopreservation on the Biological Characteristics and Cardiomyogenic Differentiation of Rat Adipose-Derived Mesenchymal Stem Cells

Cryopreservation is essential for the broad clinical application of mesenchymal stem cells (MSCs), yet its impact on their cellular characteristics and cardiomyogenic differentiation potential remains a critical concern in translational medicine. This study aimed to evaluate the effects of cryopreservation on the biological properties and cardiomyogenic capacity of rat adipose-derived MSCs (AD-MSCs). We examined their cellular morphology, surface marker expression (CD29, CD90, CD45), trilineage differentiation potential (adipogenic, osteogenic, chondrogenic), and gene expression profiles for the pluripotency marker REX1 and immunomodulatory markers TGFβ1 and IL-6. After inducing cardiomyocyte differentiation, we assessed cardiac-specific gene expressions (Troponin I, MEF2c, GSK-3β) using quantitative RT-qPCR, along with live/dead cell staining and immunofluorescence for cardiac-specific proteins (Troponin T, α-actinin, Myosin Heavy Chain). Cryopreserved AD-MSCs preserved their morphology, surface markers, and differentiation potential, but exhibited a reduced expression of REX1, TGFβ1, and IL-6. Additionally, cryopreservation diminished cardiomyogenic differentiation, as indicated by the lower levels of Troponin I, MEF2c, and GSK-3β seen compared to non-cryopreserved cells. Despite this, high cell viability (>90%) and maintained cardiac protein expression were observed post-cryopreservation. These findings highlight the necessity of optimizing cryopreservation protocols to ensure the full therapeutic potential of AD-MSCs, particularly in applications related to cardiac regenerative medicine.

The Use of Stem Cells in Bone Regeneration of Cleft Lip and Palate Patients: A Systematic Review

Background and Objectives: Cleft lip alone or a combination of cleft lip and palate (CLP) is a common developmental abnormality in the craniofacial region. This umbrella review aims to identify promising avenues for treatment using stem cell therapy. Materials and Methods: Systematic reviews from 2014 to 2024 were searched among databases like PubMed, Medline, and Google Scholar. PRISMA guidelines were employed to ensure the thoroughness of the search. A quality assessment (ROBIS) of the included reviews was conducted to ensure the reliability and validity of the synthesized evidence. Results: Five systematic reviews were selected for this umbrella review. Results show that stem cell therapy, specifically using mesenchymal stem cells (MSCs) and adipocyte stem cells (ADSCs), promotes bone regeneration in CLP deformities. Although multiple studies have established the effectiveness of diverse types of stem cells in treating CLP, important considerations including safety concerns, methodological variability, and the need for standardization have been identified. The fact that the number of relevant systematic reviews that matched our inclusion criteria was limited could affect this research's robustness and may limit the breadth and depth of evidence synthesis. Definitive conclusions could not be reached due to variation among treatments and outcomes. Conclusions: The examined studies highlight the potential of stem cell therapy as a complementary approach to existing treatments for CLP. However, there are challenges that need to be addressed, including concerns regarding safety, variations in methodologies, and the need for standardization. Exploring the potential of other stem cell types may further enhance treatment outcomes for CLP patients.

Effect of DNA methylation on the osteogenic differentiation of mesenchymal stem cells: concise review

Mesenchymal stem cells (MSCs) have promising potential for bone tissue engineering in bone healing and regeneration. They are regarded as such due to their capacity for self-renewal, multiple differentiation, and their ability to modulate the immune response. However, changes in the molecular pathways and transcription factors of MSCs in osteogenesis can lead to bone defects and metabolic bone diseases. DNA methylation is an epigenetic process that plays an important role in the osteogenic differentiation of MSCs by regulating gene expression. An increasing number of studies have demonstrated the significance of DNA methyltransferases (DNMTs), Ten-eleven translocation family proteins (TETs), and MSCs signaling pathways about osteogenic differentiation in MSCs. This review focuses on the progress of research in these areas.

Pharmacological activation of mesenchymal stem cells increases gene expression pattern of cell adhesion molecules and fusion with neonatal cardiomyocytes

Cellular therapy is considered a better option for the treatment of degenerative disorders. Different cell types are being used for tissue regeneration. Despite extensive research in this field, several issues remain to be addressed concerning cell transplantation. One of these issues is the survival and homing of administered cells in the injured tissue, which depends on the ability of these cells to adhere. To enhance cell adherence and survival, Rap1 GTPase was activated in mesenchymal stem cells (MSCs) as well as in cardiomyocytes (CMs) by using 8-pCPT-2'-O-Me-cAMP, and the effect on gene expression dynamics was determined through quantitative reverse transcriptase-polymerase chain reaction analysis. Pharmacological activation of MSCs and CMs resulted in the upregulation of connexin-43 and cell adhesion genes, which increased the cell adhesion ability of MSCs and CMs, and increased the fusion of MSCs with neonatal CMs. Treating stem cells with a pharmacological agent that activates Rap1a before transplantation can enhance their fusion with CMs and increase cellular regeneration.

Understanding molecular characteristics of extracellular vesicles derived from different types of mesenchymal stem cells for therapeutic translation

Mesenchymal stem cells (MSCs) have been studied for decades as candidates for cellular therapy, and their secretome, including secreted extracellular vesicles (EVs), has been identified to contribute significantly to regenerative and reparative functions. Emerging evidence has suggested that MSC-EVs alone, could be used as therapeutics that emulate the biological function of MSCs. However, just as with MSCs, MSC-EVs have been shown to vary in composition, depending on the tissue source of the MSCs as well as the protocols employed in culturing the MSCs and obtaining the EVs. Therefore, the importance of careful choice of cell sources and culture environments is receiving increasing attention. Many factors contribute to the therapeutic potential of MSC-EVs, including the source tissue, isolation technique, and culturing conditions. This review illustrates the molecular landscape of EVs derived from different types of MSC cells along with culture strategies. A thorough analysis of publicly available omic datasets was performed to advance the precision understanding of MSC-EVs with unique tissue source-dependent molecular characteristics. The tissue-specific protein and miRNA-driven Reactome ontology analysis was used to reveal distinct patterns of top Reactome ontology pathways across adipose, bone marrow, and umbilical MSC-EVs. Moreover, a meta-analysis assisted by an AI technique was used to analyze the published literature, providing insights into the therapeutic translation of MSC-EVs based on their source tissues.

Comprehensive characterisation and cryopreservation optimisation of buffalo (Bubalus bubalis) adipose tissue-derived mesenchymal stem cells

Over half of the world's buffalo (Bubalus bubalis) inhabit India, and buffaloes frequently encounter health challenges that resist conventional treatments, prompting the exploration of alternative therapeutic strategies. One promising approach is stem cell therapy, particularly multipotent mesenchymal/stromal stem cells (MSCs). These cells have shown significant efficacy in addressing various diseases in livestock that exhibit resistance to conventional therapies. Adipose tissue-derived MSCs (ADSCs) have garnered attention due to their accessibility and robust expansion potential. The current study comprehensively characterises buffalo ADSCs (bADSCs), confirming their identity as MSCs capable of differentiating into diverse cell lineages-the identified characteristics position bADSCs as promising candidates for applications in regenerative medicine, applicable in veterinary contexts. Notably, the study established that a cryoprotective solution comprising 10 % dimethyl sulfoxide and 90 % fetal bovine serum is optimal for preserving bADSCs. This cryoprotective solution maintains vital parameters, including viability, apoptosis, senescence, cell adherence, adherent cell viability, metabolic and clonogenic efficiency, and the activity of reactive oxygen species and trilineage differentiation potential following thawing. These findings lay the foundation for developing a cryo-banking system for bADSCs. Subsequent research efforts are focused on exploring the therapeutic potential of bADSCs in specific disease models and clinical settings. The outcomes of such investigations may pave the way for innovative and effective treatments, further enhancing our understanding of the regenerative capabilities of bADSCs.

Morinda officinalis polysaccharide promotes the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells via microRNA-210-3p/scavenger receptor class A member 3

Morinda officinalis polysaccharide (MOP) is the bioactive ingredient extracted from the root of Morinda officinalis, and Morinda officinalis is applied to treat osteoporosis (OP). The purpose of this study was to determine the role of MOP on human bone marrow mesenchymal stem cells (hBMSCs) and the underlying mechanism. HBMSCs were isolated from bone marrow samples of patients with OP and treated with MOP. Quantitative real-time polymerase chain reaction was adopted to quantify the expression of microRNA-210-3p (miR-210-3p) and scavenger receptor class A member 3 (SCARA3) mRNA. Cell Counting Kit-8 assay was employed to detect cell viability; Terminal-deoxynucleotidyl Transferase Mediated Nick End Labeling assay and flow cytometry were adopted to detect apoptosis; Alkaline Phosphatase (ALP) activity assay kit was applied to detect ALP activity; Western blot was executed to quantify the expression levels of SCARA3, osteogenic and adipogenic differentiation markers. Ovariectomized rats were treated with MOP. Bone mineral density (BMD), serum tartrate-resistant acid phosphatase 5b (TRACP 5b), and N-telopeptide of type I collagen (NTx) levels were assessed by BMD detector and Enzyme-linked immunosorbent assay kits. It was revealed that MOP could promote hBMSCs' viability and osteogenic differentiation and inhibit apoptosis and adipogenic differentiation. MOP could also upregulate SCARA3 expression through repressing miR-210-3p expression. Treatment with MOP increased the BMD and decreased the TRACP 5b and NTx levels in ovariectomized rats. MOP may boost the osteogenic differentiation and inhibit adipogenic differentiation of hBMSCs by miR-210-3p/SCARA3 axis.

Adipose-derived mesenchymal stem cells (MSCs) are a superior cell source for bone tissue engineering

Effective bone regeneration through tissue engineering requires a combination of osteogenic progenitors, osteoinductive biofactors and biocompatible scaffold materials. Mesenchymal stem cells (MSCs) represent the most promising seed cells for bone tissue engineering. As multipotent stem cells that can self-renew and differentiate into multiple lineages including bone and fat, MSCs can be isolated from numerous tissues and exhibit varied differentiation potential. To identify an optimal progenitor cell source for bone tissue engineering, we analyzed the proliferative activity and osteogenic potential of four commonly-used mouse MSC sources, including immortalized mouse embryonic fibroblasts (iMEF), immortalized mouse bone marrow stromal stem cells (imBMSC), immortalized mouse calvarial mesenchymal progenitors (iCAL), and immortalized mouse adipose-derived mesenchymal stem cells (iMAD). We found that iMAD exhibited highest osteogenic and adipogenic capabilities upon BMP9 stimulation in vitro, whereas iMAD and iCAL exhibited highest osteogenic capability in BMP9-induced ectopic osteogenesis and critical-sized calvarial defect repair. Transcriptomic analysis revealed that, while each MSC line regulated a distinct set of target genes upon BMP9 stimulation, all MSC lines underwent osteogenic differentiation by regulating osteogenesis-related signaling including Wnt, TGF-β, PI3K/AKT, MAPK, Hippo and JAK-STAT pathways. Collectively, our results demonstrate that adipose-derived MSCs represent optimal progenitor sources for cell-based bone tissue engineering.

Influence of Different Glucose Concentrations on the Expression of miR-29c-3p microRNA in Mesenchymal Stem Cells

Background: miR-29c-3p manages a set of genes involved in regenerative medicine, and It seems that hyperglycemia in diabetic patients influences the power of stem cells to tissue regeneration the difficulties of diabetes by affecting the expression miR-29c-3p in mesenchymal stem cells. The study aims to analyze the effect of various glucose concentrations on the miR-29c-3p expression in mesenchymal stem cells. Materials and Methods: After receiving donated mesenchymal stem cells from Tarbiat Modares University, these cells were cultivated in a DMEM culture medium, including three different concentrations of glucose 250, 140, and 100 mg/dl. RNA was extracted from these cells after 72 hours, the Real-Time PCR technique assessed the expression of miR-29c-3p, and the results were analyzed by REST software. Results: miR-29c-3p expression in cells at concentrations of 140 and 250 mg/dL compared to typical situations (100 mg/dl) was significantly decreased (P˂0.05), which declined at a concentration of 250 mg/dl was more. Conclusion: Reduced miR-29c-3p expression in mesenchymal stem cells in chronic and mild diabetic situations demonstrated that diabetes might be one of the significant reasons for mesenchymal stem cells' reduced ability to repair tissue damage.

Combination of human platelet lysate and 3D gelatin scaffolds to enhance osteogenic differentiation of human amniotic fluid derived mesenchymal stem cells

Bone disorders are major health issues requiring specialized care; however, the traditional bone grafting method had several limitations. Thus, bone tissue engineering has become a potential alternative. In therapeutic treatments, using fetal bovine serum (FBS) as a culture supplement may result in the risk of contamination and host immunological response; therefore, human platelet lysate (hPL) has been considered a viable alternative source. This study attempted to compare the effectiveness and safety of different culture supplements, either FBS or hPL, on the osteoblastic differentiation potential of mesenchymal stem cells derived from human amniotic fluid (hAF-MSCs) under a three-dimensional gelatin scaffold. The results indicate that hAF-MSCs have the potential to be used in clinical applications as they meet the criteria for mesenchymal stem cells based on their morphology, the expression of a particular surface antigen, their proliferation ability, and their capacity for multipotent differentiation. After evaluation by MTT and Alamar blue proliferation assay, 10% of hPL was selected. The osteogenic differentiation of hAF-MSCs under three-dimensional gelatin scaffold using osteogenic-induced media supplemented with hPL was achievable and markedly stimulated osteoblast differentiation. Moreover, the expressions of osteoblastogenic related genes, including OCN, ALP, and COL1A1, exhibited the highest degree of expression under hPL-supplemented circumstances when compared with the control and the FBS-supplemented group. The induced cells under hPL-supplemented conditions also presented the highest ALP activity level and the greatest degree of calcium accumulation. These outcomes would indicate that hPL is a suitable substitute for animal derived serum. Importantly, osteogenic differentiation of human amniotic fluid derived mesenchymal stem cells using hPL-supplemented media and three-dimensional scaffolds may open the door to developing an alternative construct for repairing bone defects.

The effects of IL-1β stimulated human umbilical cord mesenchymal stem cells on polarization and apoptosis of macrophages in rheumatoid arthritis

Macrophages play an important role in the pathogenesis of rheumatoid arthritis (RA), in which the functions of pro-inflammatory macrophages (M1) and anti-inflammatory macrophages (M2) are different. Our previous studies have demonstrated that interleukin-1β (IL-1β) stimulated human umbilical cord mesenchymal stem cells (hUCMSCs) increase the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and initiate breast cancer cell apoptosis via ligand to death receptor 4 (DR4) and DR5. In this study, we examined the effect of IL-1β stimulated hUCMSCs (IL-1β-hUCMSCs) on immunoregulation of M1 and M2 macrophages in vitro and in the RA mouse model. The results showed that IL-1β-hUCMSCs increased macrophage polarization into M2 macrophages and enhanced apoptosis of M1 macrophages in vitro. Moreover, the intravenous injected IL-1β-hUCMSCs in RA mice rehabilitated the imbalance of M1/M2 ratio and thus demonstrated the potential to reduce inflammation in RA. This study advances our knowledge of the underlying immunoregulatory mechanisms involved in IL-1β-hUCMSCs to induce M1 macrophage apoptosis and promote the anti-inflammatory polarization of M2 macrophages and demonstrates the potential of IL-1β-hUCMSCs to reduce inflammation in RA.

Induced pluripotent stem cell-based therapies for organ fibrosis

Fibrotic diseases result in organ remodelling and dysfunctional failure and account for one-third of all deaths worldwide. There are no ideal treatments that can halt or reverse progressive organ fibrosis, moreover, organ transplantation is complicated by problems with a limited supply of donor organs and graft rejection. The development of new approaches, especially induced pluripotent stem cell (iPSC)-based therapy, is becoming a hot topic due to their ability to self-renew and differentiate into different cell types that may replace the fibrotic organs. In the past decade, studies have differentiated iPSCs into fibrosis-relevant cell types which were demonstrated to have anti-fibrotic effects that may have the potential to inform new effective precision treatments for organ-specific fibrosis. In this review, we summarize the potential of iPSC-based cellular approaches as therapeutic avenues for treating organ fibrosis, the advantages and disadvantages of iPSCs compared with other types of stem cell-based therapies, as well as the challenges and future outlook in this field.