Treatment of osteoarthritis with mesenchymal stem cells

Osteoarthritis(OA)is one of the most prevalent joint diseases with prominent symptoms affecting the daily life of millions of middle aged and elderly people.Despite this,there are no successful medical interventions that can prevent the progressive destruction of OA joints.The onset of pathological changes in OA is associated with deviant activity of mesenchymal stem cells(MSCs),the multipotent precursors of connective tissue cells that reside in joints.Current therapies for OA have resulted in poor clinical outcomes without repairing the damaged cartilage.Intra-articular delivery of culture-expanded MSCs has opened new avenues of OA treatment.Pre-clinical and clinical trials demonstrated the feasibility,safety,and efficacy of MSC therapy.The Wnt/β-catenin,bone morphogenetic protein 2,Indian hedgehog,and Mitogen-activated protein kinase signaling pathways have been demonstrated to be involved in OA and the mechanism of action of MSC therapies.     

Differential expression of microRNAs in decidua-derived mesenchymal stem cells from patients with pre-eclampsia

Background

Mesenchymal stem cells (MSCs) at maternal-fetal interface are considered to play an important role in the pathogenesis of pre-eclampsia (PE). microRNAs (miRNAs) also have an important influence on differentiation, maturation, and functions of MSCs. Our aim in this study was to determine the differential expression of miRNAs in decidua-derived MSCs (dMSCs) from severe PE and normal pregnancies.

Results

miRNA expression profiles in dMSCs from five patients with severe PE and five healthy pregnant women were screened using microarray. Then, bioinformatic analysis of the microarray results was performed. Out of 179 differentially expressed miRNAs, 49 miRNAs had significant (p < 0.05) differential expression of ≥ 2.0-fold changes, including 21 up-regulated and 28 down-regulated. miRNA-Gene-network and miRNA-Gene ontology (GO) -network analyses were performed. Overall, 21 up-regulated and 15 down-regulated miRNAs showed high degrees in these analyses. Moreover, the significantly enriched signaling pathways and GOs were identified. The analyses revealed that pathways associated with cell proliferation, angiogenesis, and immune functions were highly regulated by the differentially expressed miRNAs, including Wnt signaling pathway, mitogen-activated protein kinase signaling pathway, transforming growth factor beta signaling pathway, T-cell receptor signaling pathway, and B cell receptor signaling pathway. Four miRNA predicted target genes, vascular endothelial growth factor A (VEGFA), indoleamine 2,3-dioxygenase, suppression of cytokine signaling 3, and serine/threonine protein phosphatase 2A 55 kDa regulatory subunit B α isoform (PPP2R2A) were all decreased in dMSCs from patients with PE. Furthermore, the physiological roles of miR-16 and miR-136 in the down-regulation of VEGFA and PPP2R2A, respectively, were confirmed through reporter assays.

Conclusions

These findings suggest that miRNAs in dMSCs may be important regulatory molecules in the development of PE.     

Selected reaction monitoring assays in mesenchymal stem cells from osteoarthritis patients

Osteoarthritis (OA) is considered the most prevalent form of arthritis. The aim of this study was to verify potential protein OA biomarkers by applying Selected Reaction Monitoring (SRM) assays to protein extracts obtained from Bone Marrow-Mesenchymal Stem Cells (BM-MSCs) isolated from OA patients.BM aspirates were obtained from the femoral channel of OA patients at the time of surgery and from the femoral channel of hip fracture subjects without OA during hip joint replacement surgery for the treatment of subcapital fracture.SRM results verified the differential expression of several protein biomarkers in BM-MSCs from OA patients.     

Epigenetic gene regulation in stem cells and correlation to cancer

Through the classic study of genetics, much has been learned about the regulation and progression of human disease. Specifically, cancer has been defined as a disease driven by genetic alterations, including mutations in tumor-suppressor genes and oncogenes, as well as chromosomal abnormalities. However, the study of normal human development has identified that in addition to classical genetics, regulation of gene expression is also modified by ‘epigenetic’ alterations including chromatin remodeling and histone variants, DNA methylation, the regulation of polycomb group proteins, and the epigenetic function of non-coding RNA. These changes are modifications inherited during both meiosis and mitosis, yet they do not result in alterations of the actual DNA sequence. A number of biological questions are directly influenced by epigenetics, such as how does a cell know when to divide, differentiate or remain quiescent, and more importantly, what happens when these pathways become altered? Do these alterations lead to the development and/or progression of cancer? This review will focus on summarizing the limited current literature involving epigenetic alterations in the context of human cancer stems cells (CSCs). The extent to which epigenetic changes define cell fate, identity, and phenotype are still under intense investigation, and many questions remain largely unanswered. Before discussing epigenetic gene silencing in CSCs, the different classifications of stem cells and their properties will be introduced. This will be followed by an introduction to the different epigenetic mechanisms. Finally, there will be a discussion of the current knowledge of epigenetic modifications in stem cells, specifically what is known from rodent systems and established cancer cell lines, and how they are leading us to understand human stem cells.     

Intra‐articular injection of autologous adipose‐derived mesenchymal stem cells in the treatment of knee osteoarthritis

Background

Osteoarthritis (OA) is a chronic degenerative joint disease and is considered to be the fourth leading cause of disability and the second cause of inability to work in men. Recently, adipose‐derived mesenchymal stem cells (AD‐MSCs) came into focus for regenerative medicine as a promising tool for the treatment of OA. The administration of stem cells into impaired joints results in pain relief and improves quality of life, accompanied by restoration of hyaline articular cartilage.

Methods

In the present study, nine patients (including two patients with bilateral symptoms) diagnosed with osteoarthritis (International Knee Documentation grade B in 5 and grade D in six knees) were treated using a single injection of AD‐MSCs at a concentration of 0.5–1.0 × 10⁷ cells and were followed up for 18 months. During follow‐up, all the cases were evaluated clinically by Knee Society score (KSS), Hospital for Special Surgery knee score (HSS‐KS), Tegner–Lysholm (T–L) score and visual analogue scale (VAS) of pain, as well as by plain radiography and by magnetic resonance imaging visualization with 2D Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score assessment.

Results

Significant improvement of all four clinical scores was observed within the first 6 months (KSS for 41.4 points, HSS‐KS for 33.9 points, T–L score for 44.8 points, VAS of pain from 54.5 to 9.3) and improvement persisted throughout the rest of the follow‐up. MOCART score showed significant cartilage restoration (from 43 ± 7.2 to 63 ± 17.1), whereas radiography showed neither improvement, nor further joint degeneration.

Conclusions

The results obtained in the present study provide good basis for prospective randomized controlled clinical trials with respect to the use of AD‐MSCs in the treatment of osteoarthritis.     

Prostanoid pattern and iNOS expression during chondrogenic differentiation of human mesenchymal stem cells

Availability of human chondrocytes is a major limiting factor regarding drug discovery projects and tissue replacement therapies. As an alternative human mesenchymal stem cells (hMSCs) from bone marrow are taken into consideration as they can differentiate along the chondrogenic lineage. However, it remains to be shown whether they could form a valid model for primary chondrocytes with regards to inflammatory mediator production, like nitric oxide (NO) and prostanoids. We therefore investigated the production of NO and prostanoids in hMSCs over the course of chondrogenic differentiation and in response to IL-1beta using primary OA chondrocytes as reference. Chondrogenic differentiation was monitored over 28 days using collagen I, collagen II, and collagen X expression levels. Expression levels of inducible nitric oxide synthase (iNOS), levels of NO, and prostanoids were assessed using PCR, Griess assay, and GC/MS/MS, respectively. The hMSCs collagen expression profile during course of differentiation was consistent with a chondrocytic phenotype. Contrary to undifferentiated cells, differentiated hMSCs expressed iNOS and produced NO following stimulation with IL-1beta. Moreover, this induction of iNOS expression was corticosteroid insensitive. The spectrum of prostanoid production in differentiated hMSCs showed similarities to that of OA chondrocytes, with PGE2 as predominant product. We provide the first detailed characterization of NO and prostanoid production in hMSCs in the course of chondrogenic differentiation. Our results suggest that differentiated hMSCs form a valid model for chondrocytes concerning inflammatory mediator production. Furthermore, we propose that IL-1beta stimulation, leading to corticosteroid-insensitive NO synthesis, can be used as a sensitive marker of chondrogenesis.     

Safety and efficacy of allogenic placental mesenchymal stem cells for treating knee osteoarthritis: a pilot study

Objective

Knee osteoarthritis (OA) is a common skeletal impairment that can cause many limitations in normal life activities. Stem cell therapy has been studied for decades for its regenerative potency in various diseases. We investigated the safety and efficacy of intra-articular injection of placental mesenchymal stem cells (MSCs) in knee OA healing.

Biologic properties of mesenchymal stem cells derived from bone marrow and adipose tissue

The biologic characteristics of mesenchymal stem cells (MSCs) isolated from two distinct tissues, bone marrow and adipose tissue were evaluated in these studies. MSCs derived from human and non-human primate (rhesus monkey) tissue sources were compared. The data indicate that MSCs isolated from rhesus bone marrow (rBMSCs) and human adipose tissue (hASCs) had more similar biologic properties than MSCs of rhesus adipose tissue (rASCs) and human bone marrow MSCs (hBMSCs). Analyses of in vitro growth kinetics revealed shorter doubling time for rBMSCs and hASCs. rBMSCs and hASCs underwent significantly more population doublings than the other MSCs. MSCs from all sources showed a marked decrease in telomerase activity over extended culture; however, they maintained their mean telomere length. All of the MSCs expressed embryonic stem cell markers, Oct-4, Rex-1, and Sox-2 for at least 10 passages. Early populations of MSCs types showed similar multilineage differentiation capability. However, only the rBMSCs and hASCs retain greater differentiation efficiency at higher passages. Overall in vitro characterization of MSCs from these two species and tissue sources revealed a high level of common biologic properties. However, the results demonstrate clear biologic distinctions, as well.     

DNA methylation and hydroxymethylation in stem cells

In mammals, DNA methylation and hydroxymethylation are specific epigenetic mechanisms that can contribute to the regulation of gene expression and cellular functions. DNA methylation is important for the function of embryonic stem cells and adult stem cells (such as haematopoietic stem cells, neural stem cells and germline stem cells), and changes in DNA methylation patterns are essential for successful nuclear reprogramming. In the past several years, the rediscovery of hydroxymethylation and the TET enzymes expanded our insights tremendously and uncovered more dynamic aspects of cytosine methylation regulation. Here, we review the current knowledge and highlight the most recent advances in DNA methylation and hydroxymethylation in embryonic stem cells, induced pluripotent stem cells and several well‐studied adult stems cells. Our current understanding of stem cell epigenetics and new advances in the field will undoubtedly stimulate further clinical applications of regenerative medicine in the future. Copyright © 2015 John Wiley & Sons, Ltd.     

Growth factors and chondrogenic differentiation of mesenchymal stem cells

The main purpose of the article is to review recent knowledge about growth factors and their effect on the chondrogenic differentiation of mesenchymal stem cells under in vitro conditions. Damaged or lost articular cartilage leads to progressive debilitation, which have major impact on the life quality of the affected individuals of both sexes in all age groups. Mature hyaline cartilage has a very low self-repair potential due to intrinsic properties - lack of innervation and vascular supply. Another limiting factor is low mitotic potential of chondrocytes. Small defects are healed by migration of chondrocytes, while large ones are healed by formation of inferior fibrocartilage. However, in many cases osteoarthritis develops. Recently, cellular therapy combining mesenchymal stem cells and proper differentiation factors seems to be promising tool for hyaline cartilage defects healing.     

Mechanisms of analgesic effect of mesenchymal stem cells in osteoarthritis pain

Osteoarthritis (OA) is the most common musculoskeletal disease, and it is a major cause of pain, disability and health burden. Pain is the most common and bothersome presentation of OA, but its treatment is still suboptimal, due to the short-term action of employed analgesics and their poor adverse effect profile. Due to their regenerative and anti-inflammatory properties, mesenchymal stem cells (MSCs) have been extensively investigated as a potential therapy for OA, and numerous preclinical and clinical studies found a significant improvement in joint pathology and function, pain scores and/or quality of life after administration of MSCs. Only a limited number of studies, however, addressed pain control as the primary end-point or investigated the potential mechanisms of analgesia induced by MSCs. In this paper, we review the evidence reported in literature that support the analgesic action of MSCs in OA, and we summarize the potential mechanisms of these antinociceptive effects.