Differences in surface marker expression and chondrogenic potential among various tissue-derived mesenchymal cells from elderly patients with osteoarthritis

Umbilical Cord-Derived Stem Cells for the Treatment of Knee Osteoarthritis: A Systematic Review

Background:

The use of mesenchymal stem cells (MSCs) for the treatment of knee osteoarthritis (OA) has gained recent interest in the orthopaedics community.

Purpose:

To review the literature to evaluate the efficacy of umbilical cord–derived MSCs in the treatment of OA of the knee joint.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

We searched the PubMed, Cochrane Library, and Embase databases to identify studies with evidence levels from 1 to 4 that evaluated the clinical efficacy of human umbilical cord–derived MSC (hUC-MSC) injections for knee OA. The search phrase used was “umbilical cord knee osteoarthritis.” In the studies reviewed, patients were assessed based on the macroscopic International Cartilage Regeneration & Joint Preservation Society (ICRS) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS) for pain, and the subjective International Knee Documentation Committee (IKDC) score.

Results:

A total of 7 studies met inclusion criteria, including 385 patients undergoing injection of hUC-MSCs (mean age, 59.7 years). The mean follow-up was 23.4 months. Weighted averages of the WOMAC, macroscopic ICRS, subjective IKDC, and VAS scores all showed improvement from before to after treatment. No severe adverse reactions were recorded.

Conclusion:

Patients undergoing treatment of knee OA with hUC-MSCs might be expected to experience improvements in clinical outcomes. Additional high-quality randomized studies are needed to better determine the efficacy of hUC-MSC for the treatment of knee OA.

Morphological and Molecular Features of Porcine Mesenchymal Stem Cells Derived From Different Types of Synovial Membrane, and Genetic Background of Cell Donors

Synovial mesenchymal stem cells (SMSCs) have become a great cell source for musculoskeletal stem cell research, especially related to cartilage and bone tissue regeneration, due to their superior cell proliferation properties and multidifferentiation potential into various cell lineages. This study revealed isolation methods, culture conditions, and morphological and molecular characterization of SMSCs derived fibrous synovium (FS) and adipose synovium (FP) of two pig breeds differing in growth performance [German Landrace (DL), and fat deposition (Angeln Saddleback (AS)]. Herein, FS possessed nucleated cell numbers nearly twice as high as those of FP at Passage 0. SMSCs derived from different types of synovial membrane and genetic background show similar cell morphologies and immunophenotypes, which were assessed by cell surface epitopes and multilineage differentiation potential, but differ significantly in their molecular characteristics. In addition, transcripts of SMSCs from AS were more enriched in IGF-1 signaling and VEGF ligand receptor, while SMSCs from DL were more enriched in growth hormone signaling and bone metabolism. The results indicate that genetics and tissues play significant roles for SMSC characteristics so that SMSCs can be traced back to the original cell donor and be used for fine turning in applications of medical research and therapies.

Identification of TGFβ signatures in six murine models mimicking different osteoarthritis clinical phenotypes

OBJECTIVE

TGFβ is a key player in cartilage homeostasis and OA pathology. However, few data are available on the role of TGFβ signalling in the different OA phenotypes. Here, we analysed the TGFβ pathway by transcriptomic analysis in six mouse models of OA.

METHOD

We have brought together seven expert laboratories in OA pathophysiology and, used inter-laboratories standard operating procedures and quality controls to increase experimental reproducibility and decrease bias. As none of the available OA models covers the complexity and heterogeneity of the human disease, we used six different murine models of knee OA: from post-traumatic/mechanical models (meniscectomy (MNX), MNX and hypergravity (HG-MNX), MNX and high fat diet (HF-MNX), MNX and seipin knock-out (SP-MNX)) to aging-related OA and inflammatory OA (collagenase-induced OA (CIOA)). Four controls (MNX-sham, young, SP-sham, CIOA-sham) were added. OsteoArthritis Research Society International (OARSI)-based scoring of femoral condyles and ribonucleic acid (RNA) extraction from tibial plateau samples were done by single operators as well as the transcriptomic analysis of the TGFβ family pathway by Custom TaqMan® Array Microfluidic Cards.

RESULTS

The transcriptomic analysis revealed specific gene signatures in each of the six models; however, no gene was deregulated in all six OA models. Of interest, we found that the combinatorial Gdf5-Cd36-Ltbp4 signature might discriminate distinct subgroups of OA: Cd36 upregulation is a hallmark of MNX-related OA while Gdf5 and Ltbp4 upregulation is related to MNX-induced OA and CIOA.

CONCLUSION

These findings stress the OA animal model heterogeneity and the need of caution when extrapolating results from one model to another.

Respective stemness and chondrogenic potential of mesenchymal stem cells isolated from human bone marrow, synovial membrane, and synovial fluid

BACKGROUND

MSCs isolated from bone marrow (BM-MSCs) have well-established chondrogenic potential, but MSCs derived from the synovial membrane (SM-MSCs) and synovial fluid (SF-MSCs) are thought to possess superior chondrogenicity. This study aimed to compare the in vitro immunophenotype and trilineage and chondrogenic potential of BM-MSCs to SM-MSCs and SF-MSCs.

METHODS

MSCs were isolated from bone marrow (BM-MSCs), synovial membrane (SM-MSCs), and synovial fluid (SF-MSCs) extracted from the hips (BM) and knees (SM and SF) of advanced OA patients undergoing arthroplasty. Flow cytometric analysis was used at P2 to evaluate cell stemness. The trilinear differentiation test was performed at P2. At P3, MSC-seeded collagen sponges were cultured in chondrogenic medium for 28 days. Chondrogenic gene expression was quantified by qRT-PCR. Finally, the implants were stained to assess the deposition of proteoglycans and type II collagen.

RESULTS

Despite variability, the immunophenotyping of BM-MSCs, SM-MSCs, and SF-MSCs was quite similar. All cell types were positive for the expression of stem cell markers and negative for exclusion markers. Additionally, chondrogenic differentiation and hypertrophy were more pronounced in BM-MSCs (ACAN, SOX9, COL2B, and COL10A) than in SF-MSCs, with SM-MSCs having intermediate characteristics. Concerning matrix synthesis, the three cell types were equipotent in terms of GAG content, while BM-MSC ECM synthesis of type II collagen was superior.

CONCLUSIONS

Chondrogenic MSCs are easily collected from SM and SF in advanced human OA, but in vitro chondrogenesis that is superior to age-matched BM-MSCs should not be expected. However, due to intra-articular priming, SF-MSCs did not overexpress hypertrophic gene.

Site-Dependent Lineage Preference of Adipose Stem Cells

Adult stem cells have unique properties in both proliferation and differentiation preference. In this study, we hypothesized that adipose stem cells have a depot-dependent lineage preference. Four rabbits were used to provide donor-matched adipose stem cells from either subcutaneous adipose tissue (ScAT) or infrapatellar fat pad (IPFP). Proliferation and multi-lineage differentiation were evaluated in adipose stem cells from donor-matched ScAT and IPFP. RNA sequencing (RNA-seq) and proteomics were conducted to uncover potential molecular discrepancy in adipose stem cells and their corresponding matrix microenvironments. We found that stem cells from ScAT exhibited significantly higher proliferation and adipogenic capacity compared to those from donor-matched IPFP while stem cells from IPFP displayed significantly higher chondrogenic potential compared to those from donor-matched ScAT. Our findings are strongly endorsed by supportive data from transcriptome and proteomics analyses, indicating a site-dependent lineage preference of adipose stem cells.

Commentary on 'Surface markers associated with chondrogenic potential of human mesenchymal stromal/stem cells'

In the last decade, researchers have searched for predictive surface markers of multipotent mesenchymal stromal/stem cells (MSCs) for ensuring improved therapeutic outcomes following cartilage damage in humans. However, we have achieved only limited progress because of the challenge presented by conflicting data. This commentary provides some evidence to prove a lack of success with current efforts, including an inconsistency in accepted surface markers and chondrogenic potential of MSCs as well as the tissue source-dependent MSC surface markers that correlate with chondrogenic potential. A brief discussion on these disputed topics and perspective about functionally predictive surface markers and standardization of analytic procedures are also highlighted.

Donor-matched comparison of chondrogenic progenitors resident in human infrapatellar fat pad, synovium, and periosteum - implications for cartilage repair

Purpose: There is a clinical need to better characterize tissue sources being used for stem cell therapies. This study focuses on comparison of cells and connective tissue progenitors (CTPs) derived from native human infrapatellar fatpad (IPFP), synovium (SYN), and periosteum (PERI). Materials and Methods: IPFP, SYN, PERI were harvested from twenty-eight patients undergoing arthroplasty. CTPs were quantitatively characterized using automated colony-forming-unit assay to compare total nucleated cell concentration-[Cell], cells/mg; prevalence-(P_CTP), CTPs/million nucleated cells; CTP concentration-[CTP], CTPs/mg; proliferation and differentiation potential; and correlate outcomes with patient's age and gender. Results: [Cell] did not differ between IPFP, SYN, and PERI. P_CTP was influenced by age and gender: patients >60 years, IPFP and SYN had higher P_CTP than PERI (p < 0.001) and females had higher P_CTP in IPFP (p < 0.001) and SYN (p = 0.001) than PERI. [CTP] was influenced by age: patients <50 years, SYN (p = 0.0165) and PERI (p < 0.001) had higher [CTP] than IPFP; patients between 60 and 69 years, SYN (p < 0.001) had higher [CTP] than PERI; patients >70 years, IPFP (p = 0.006) had higher [CTP] than PERI. In patients >60 years, proliferation potential of CTPs differed significantly (SYN>IPFP>PERI); however, differentiation potentials were comparable between all three tissue sources. Conclusion: SYN and IPFP may serve as a preferred tissue source for patients >60 years, and PERI along with SYN and IPFP may serve as a preferred tissue source for patients <60 years for cartilage repair. However, the heterogeneity among the CTPs in any given tissue source suggests performance-based selection might be useful to optimize cell-sourcing strategies to improve efficacy of cellular therapies for cartilage repair.

Osteochondral repair using an acellular dermal matrix-pilot in vivo study in a rabbit osteochondral defect model

The aim of this pilot project was to introduce a novel use of acellular dermal matrix (ADM) in combination with infrapatellar fat pad mesenchymal stromal cells (IPFP-MSCs) to effect repair in a rabbit osteochondral defect model. ADM, in a range of surgical procedures, has been shown to promote remodelling of tissue at the site of implantation. Rabbit-derived ADM (rabADM) was prepared from the skin of donor rabbits. Autologous IPFP-MSCs were obtained at the time of knee surgery. Osteochondral defects (4 mm cartilage outer/2 mm central bone defect) were drilled into distal femoral condyles of 12 New Zealand White rabbits. Treatments groups: (i) defect only; (ii) rabADM alone; (iii) IPFP-MSCs alone; and (iv) rabADM with IPFP-MSCs. Condyles were harvested at 12 weeks, and analyzed using histology, immunohistochemistry (types I and II collagen) and histomorphometry to evaluate osteochondral repair. The rabADM only group achieved the highest ratio of type II to non-type II collagen (77.3%) using areal measures (similar to normal cartilage), which indicated a higher quality of cartilage repair. The addition of IPFP-MSCs, with or without rabADM, formed a fibrous collagen cap above the lesion site not seen with rabADM alone. Macroscopically, there was no joint erosion, inflammation, swelling or deformity, and all animals maintained full range of motion.

CONCLUSIONS

RabADM alone resulted in neocartilage formation similar to native cartilage. IPFP-MSCs limited osteochondral repair and contributed to fibrosis, even in combination with the rabADM. Further studies using ADM for osteochondral repair are warranted in a more appropriate pre-clinical model of osteochondral repair. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1919-1928, 2018.

Isolating Pediatric Mesenchymal Stem Cells with Enhanced Expansion and Differentiation Capabilities

Mesenchymal stem cells/marrow stromal cells (MSCs) are attractive for applications ranging from research and development to use in clinical therapeutics. However, the most commonly studied MSCs, adult bone marrow MSCs (A-MSCs), are limited by significant donor variation resulting in inconsistent expansion rates and multilineage differentiation capabilities. We have recently obtained permission to isolate pediatric MSCs (P-MSCs) from surplus iliac crest bone chips. Here, we developed a simple and easily replicable isolation protocol yielding P-MSCs, which adhere to MSC defining guidelines. After confirming immunophenotypic marker expression, we compared expansion rates, senescence, morphology, and trilineage differentiation of P-MSCs to A-MSCs for multiple donors. We found P-MSCs have faster in vitro replication, consistently show significantly lower senescence, and are capable of more reproducible multilineage differentiation than A-MSCs. We, therefore, believe P-MSCs are a promising candidate for use in research applications and potentially as part of an allogeneic therapeutic treatment.

Infrapatellar fat pad-derived mesenchymal stromal cells from osteoarthritis patients: In vitro genetic stability and replicative senescence

Different sources of mesenchymal stromal cells can be considered for regenerative medicine applications. Here we analyzed human adipose-derived stromal cells from infrapatellar fat pad (IFPSC) of osteoarthritis patients, representing a very interesting candidate for cartilage regeneration. No data are available concerning IFPSC stability after in vitro expansion. Indeed, replicative potential and multipotency progressively decrease during culture passages while DNA damage and cell senescence increase, thus possibly affecting clinical applications. To investigate whether in vitro expansion influences the genetic stability and replicative senescence of IFPSC, we performed long-term cultures and comparatively analyzed cells at different culture passages. Stromal vascular fraction was harvested from infrapatellar fat pad of 11 osteoarthritis patients undergoing knee replacement surgery. Cell recovery, growth kinetics, surface marker profile, and differentiation ability in inductive culture conditions were recorded. Genetic integrity maintenance was estimated by microsatellite instability analysis and mismatch repair gene expression, whereas telomere length and telomerase activity were assessed to evaluate replicative senescence. Anchorage-dependent growth was tested by soft agar culture. IFPSC displayed a phenotype similar to mesenchymal stromal cells from subcutaneous fat and showed differentiation ability. No microsatellite instability was documented even at advanced culture times in accordance to a sustained expression of mismatch repair genes, thus highlighting stability of short repeated sequences in the genome. No significant telomere attrition nor telomerase activity were documented during culture and cells did not lose anchorage-dependent growth ability. The presented data support the suitability and safety of in vitro expanded IFPSC from osteoarthritis patients for applications in regenerative medicine approaches. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1029-1037, 2017.

Selective isolation and characterization of primary cells from normal breast and tumors reveal plasticity of adipose derived stem cells

Background

There is a need to establish more cell lines from breast tumors in contrast to immortalized cell lines from metastatic effusions in order to represent the primary tumor and not principally metastatic biology of breast cancer. This investigation describes the simultaneous isolation, characterization, growth and function of primary mammary epithelial cells (MEC), mesenchymal cells (MES) and adipose derived stem cells (ADSC) from four normal breasts, one inflammatory and one triple-negative ductal breast tumors.

Methods

A total of 17 cell lines were established and gene expression was analyzed for MEC and MES (n = 42) and ADSC (n = 48) and MUC1, pan-KRT, CD90 and GATA-3 by immunofluorescence. DNA fingerprinting to track cell line identity was performed between original primary tissues and isolates. Functional studies included ADSC differentiation, tumor MES and MEC invasion co-cultured with ADSC-conditioned media (CM) and MES adhesion and growth on 3D-printed scaffolds.

Results

Comparative analysis showed higher gene expression of EPCAM, CD49f, CDH1 and KRTs for normal MEC lines; MES lines e.g. Vimentin, CD10, ACTA2 and MMP9; and ADSC lines e.g. CD105, CD90, CDH2 and CDH11. Compared to the mean of all four normal breast cell lines, both breast tumor cell lines demonstrated significantly lower ADSC marker gene expression, but higher expression of mesenchymal and invasion gene markers like SNAI1 and MMP2. When compared with four normal ADSC differentiated lineages, both tumor ADSC showed impaired osteogenic and chondrogenic but enhanced adipogenic differentiation and endothelial-like structures, possibly due to high PDGFRB and CD34. Addressing a functional role for overproduction of adipocytes, we initiated 3D-invasion studies including different cell types from the same patient. CM from ADSC differentiating into adipocytes induced tumor MEC 3D-invasion via EMT and amoeboid phenotypes. Normal MES breast cells adhered and proliferated on 3D-printed scaffolds containing 20 fibers, but not on 2.5D-printed scaffolds with single fiber layers, important for tissue engineering.

Conclusion

Expression analyses confirmed successful simultaneous cell isolations of three different phenotypes from normal and tumor primary breast tissues. Our cell culture studies support that breast-tumor environment differentially regulates tumor ADSC plasticity as well as cell invasion and demonstrates applications for regenerative medicine.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-016-0688-2) contains supplementary material, which is available to authorized users.

Application of cell and biomaterial-based tissue engineering methods in the treatment of cartilage, menisci and ligament injuries

Over 20 years ago it was realized that the traditional methods of the treatment of injuries to joint components: cartilage, menisci and ligaments, did not give satisfactory results and so there is a need of employing novel, more effective therapeutic techniques. Recent advances in molecular biology, biotechnology and polymer science have led to both the experimental and clinical application of various cell types, adapting their culture conditions in order to ensure a directed differentiation of the cells into a desired cell type, and employing non-toxic and non-immunogenic biomaterial in the treatment of knee joint injuries. In the present review the current state of knowledge regarding novel cell sources, in vitro conditions of cell culture and major important biomaterials, both natural and synthetic, used in cartilage, meniscus and ligament repair by tissue engineering techniques are described, and the assets and drawbacks of their clinical application are critically evaluated.

Effect of Fibroblast Growth Factor 2 on Equine Synovial Fluid Chondroprogenitor Expansion and Chondrogenesis

Mesenchymal stem cells have been identified in the synovial fluid of several species. This study was conducted to characterize chondroprogenitor (CP) cells in equine synovial fluid (SF) and to determine the effect of fibroblast growth factor 2 (FGF-2) on SF-CP monolayer proliferation and subsequent chondrogenesis. We hypothesized that FGF-2 would stimulate SF-CP proliferation and postexpansion chondrogenesis. SF aspirates were collected from adult equine joints. Colony-forming unit (CFU) assays were performed during primary cultures. At first passage, SF-cells were seeded at low density, with or without FGF-2. Following monolayer expansion and serial immunophenotyping, cells were transferred to chondrogenic pellet cultures. Pellets were analyzed for chondrogenic mRNA expression and cartilage matrix secretion. There was a mean of 59.2 CFU/mL of SF. FGF-2 increased the number of population doublings during two monolayer passages and halved the population doubling times. FGF-2 did not alter the immunophenotype of SF-CPs during monolayer expansion, nor did FGF-2 compromise chondrogenesis. Hypertrophic phenotypic markers were not expressed in control or FGF-2 groups. FGF-2 did prevent the development of a “fibroblastic” cell layer around pellet periphery. FGF-2 significantly accelerates in vitro SF-CP expansion, the major hurdle to clinical application of this cell population, without detrimentally affecting subsequent chondrogenic capacity.

An emerging player in knee osteoarthritis: the infrapatellar fat pad

The role of inflammation in the development, progression, and clinical features of osteoarthritis has become an area of intense research in recent years. This led to the recognition of synovitis as an important source of inflammation in the joint and indicated that synovitis is intimately associated with pain and osteoarthritis progression. In this review, we discuss another emerging source of inflammation that could play a role in disease development/progression: the infrapatellar fat pad (IFP). The aim of this review is to offer a comprehensive view of the pathology of IFP as obtained from magnetic resonance studies, along with its characterization at both the cellular and the molecular level. Furthermore, we discuss the possible function of this organ in the pathological processes in the knee by summarizing the knowledge regarding the interactions between IFP and other joint tissues and discussing the pro- versus anti-inflammatory functions this tissue could have. We hope that this review will offer an overview of all published data regarding the IFP and will indicate novel directions for future research.

Cell-based approaches to joint surface repair: a research perspective

Repair of lesions of the articular cartilage lining the joints remains a major clinical challenge. Surgical interventions include osteochondral autograft transfer and microfracture. They can provide some relief of symptoms to patients, but generally fail to durably repair the cartilage. Autologous chondrocyte implantation has thus far shown the most promise for the durable repair of cartilage, with long-term follow-up studies indicating improved structural and functional outcomes. However, disadvantages of this technique include the need for additional surgery, availability of sufficient chondrocytes for implantation, and maintenance of their phenotype during culture-expansion. Mesenchymal stem cells offer an attractive alternative cell-source for cartilage repair, due to their ease of isolation and amenability to ex vivo expansion while retaining stem cell properties. Preclinical and clinical studies have demonstrated the potential of mesenchymal stem cells to promote articular cartilage repair, but have also highlighted several key challenges. Most notably, the quality and durability of the repair tissue, its resistance to endochondral ossification, and its effective integration with the surrounding host tissue. In addition, challenges exist related to the heterogeneity of mesenchymal stem cell preparations and their quality-control, as well as optimising the delivery method. Finally, as our knowledge of the cellular and molecular mechanisms underlying articular cartilage repair increases, promising studies are emerging employing bioactive scaffolds or therapeutics that elicit an effective tissue repair response through activation and mobilisation of endogenous stem and progenitor cells.

A two-step method of constructing mature cartilage using bone marrow-derived mesenchymal stem cells

Bone marrow-derived mesenchymal stem cells (BMSCs) are a promising source of stem cells for tissue engineering in cartilage repair. However, construction of cartilage using BMSCs can involve many problems, such as fibrosis, vascularization, the 'hollow' phenomenon and shrinkage, which may be caused by the incomplete differentiation of BMSCs and prevent the clinical application of tissue-engineered cartilage. A novel induction system that facilitates chondrogenesis by swine BMSCs has been developed. In this study, we constructed cartilage using a two-step procedure: first, promoting complete chondrogenic differentiation of BMSCs in 8 weeks, and second, these chondrocytes which differentiated from BMSCs in vitro were provided with a three-dimensional scaffold, which was then implanted subcutaneously. The results indicate that this two-step construction procedure can promote the full chondrogenic differentiation of BMSCs in vitro and the formation of mature ectopic cartilage by BMSCs in vivo.

The uncertain role of unmodified mesenchymal stem cells in tumor progression: what master switch?

Mesenchymal stem cells (MSCs) are emerging as promising gene vectors for cancer therapy because of their unique characteristics, including the ease of their expansion and genetic modification and their remarkable tumor-tropic properties. However, there remains a concern that MSCs may promote cancer progression. Surprisingly, there are conflicting reports within the literature describing both the promotion and inhibition of cancer progression by MSCs. The reasons for this discrepancy are still unknown. The surface markers, differentiation ability, and tumorigenic roles of MSCs, as well as their effect on immunoregulation, produce heterogeneity. In this review, we describe the heterogeneity of MSCs by the species from which they are derived, the methodology for their isolation and the context of their interactions with cancer cells. The conflicting roles of MSCs in tumor progression may be attributable to the bimodal effect of unmodified MSCs on immunoregulation. MSCs have been reported to suppress T-cell function and inhibit graft-versus-host disease (GVHD). On the other hand, MSCs elicit the graft-versus-tumor (GVT) effect in some cases. Selective allodepletion may be used to dissociate GVHD from the GVT effect. Understanding the conditions that balance GVHD and the GVT effect of MSCs may be crucial to advance cancer therapy research with respect to MSCs.