Human embryonic stem cell-derived mesenchymal progenitors: an overview

MSCs vs. iPSCs: Potential in therapeutic applications

Over the past 2 decades, mesenchymal stem cells (MSCs) have attracted a lot of interest as a unique therapeutic approach for a variety of diseases. MSCs are capable of self-renewal and multilineage differentiation capacity, immunomodulatory, and anti-inflammatory properties allowing it to play a role in regenerative medicine. Furthermore, MSCs are low in tumorigenicity and immune privileged, which permits the use of allogeneic MSCs for therapies that eliminate the need to collect MSCs directly from patients. Induced pluripotent stem cells (iPSCs) can be generated from adult cells through gene reprogramming with ectopic expression of specific pluripotency factors. Advancement in iPS technology avoids the destruction of embryos to make pluripotent cells, making it free of ethical concerns. iPSCs can self-renew and develop into a plethora of specialized cells making it a useful resource for regenerative medicine as they may be created from any human source. MSCs have also been used to treat individuals infected with the SARS-CoV-2 virus. MSCs have undergone more clinical trials than iPSCs due to high tumorigenicity, which can trigger oncogenic transformation. In this review, we discussed the overview of mesenchymal stem cells and induced pluripotent stem cells. We briefly present therapeutic approaches and COVID-19-related diseases using MSCs and iPSCs.

Cell Sources for Cartilage Repair-Biological and Clinical Perspective

Cell-based therapy represents a promising treatment strategy for cartilage defects. Alone or in combination with scaffolds/biological signals, these strategies open many new avenues for cartilage tissue engineering. However, the choice of the optimal cell source is not that straightforward. Currently, various types of differentiated cells (articular and nasal chondrocytes) and stem cells (mesenchymal stem cells, induced pluripotent stem cells) are being researched to objectively assess their merits and disadvantages with respect to the ability to repair damaged articular cartilage. In this paper, we focus on the different cell types used in cartilage treatment, first from a biological scientist’s perspective and then from a clinician’s standpoint. We compare and analyze the advantages and disadvantages of these cell types and offer a potential outlook for future research and clinical application.

Human Hemangioblast-Derived Mesenchymal Stem Cells Promote Islet Engraftment in a Minimal Islet Mass Transplantation Model in Mice

Islet transplantation can restore glycemic control in patients with type 1 diabetes. Using this procedure, the early stages of engraftment are often crucial to long-term islet function, and outcomes are not always successful. Numerous studies have shown that mesenchymal stem cells (MSCs) facilitate islet graft function. However, experimental data can be inconsistent due to variables associated with MSC generation (including donor characteristics and tissue source), thus, demonstrating the need for a well-characterized and uniform cell product before translation to the clinic. Unlike bone marrow- or adipose tissue-derived MSCs, human embryonic stem cell-derived-MSCs (hESC-MSCs) offer an unlimited source of stable and highly-characterized cells that are easily scalable. Here, we studied the effects of human hemangioblast-derived mesenchymal cells (HMCs), (i.e., MSCs differentiated from hESCs using a hemangioblast intermediate), on islet cell transplantation using a minimal islet mass model. The co-transplantation of the HMCs allowed a mass of islets that was insufficient to correct diabetes on its own to restore glycemic control in all recipients. Our in vitro studies help to elucidate the mechanisms including reduction of cytokine stress by which the HMCs support islet graft protection in vivo. Derivation, stability, and scalability of the HMC source may offer unique advantages for clinical applications, including fewer islets needed for successful islet transplantation.

Clinical-Grade Human Embryonic Stem Cell-Derived Mesenchymal Stromal Cells Ameliorate the Progression of Osteoarthritis in a Rat Model

Mesenchymalstem cell (MSC)-based therapy is being increasingly explored in preclinical and clinical studies as a regenerative method for treating osteoarthritis (OA). However, the use of primary MSCs is hampered by a number of limitations, including donor heterogeneity and inconsistent cell quality. Here, we tested the therapeutic potential of embryonic stem cell-derived MSCs (ES-MSCs) in anOA rat model. ES-MSCs were generated and identified by morphology, trilineage differentiation and flow cytometry. Sprague Dawley rats were treated with either a single dose (10⁶ cells/rat) of ES-MSCs or with three doses spaced one week apart for each dose, starting at four weeks after anterior cruciate ligament transectionto induce OA. Cartilage quality was evaluated at 6 and 10 weeks after treatment with behavioral analysis, macroscopic examination, and histology. At sixweeks after treatment, the groups treated with both single and repeated doses of ES-MSCs had significantly better modified Mankin scores and International Cartilage Repair Society (ICRS) macroscopic scores in the femoral condyle compared to the control group. At 10 weeks after treatment, the repeated doses group had a significantly better ICRS macroscopic scores in the femoral condyle compared to the single dose and control groups. Histological analysis also showed more proteoglycan and less cartilage loss, along with lower Mankin scores in the repeated doses group. In conclusion, treatment with multiple injections of ES-MSCs can ameliorate OA in a rat model. TheES-MSCs have potential to be considered as a regenerative therapy for OA, and can provide an infinite cellular source.

Synergistic Adhesiveness of Fibronectin with PHSRN Peptide in Gelatin Mixture Promotes the Therapeutic Potential of Human ES-Derived MSCs

Introduction

Mesenchymal stem cells (MSCs) are promising candidates for cell therapy owing to their therapeutic effect in various diseases. In general, MSCs grow efficiently in serum-containing culture media, indicating an essential role of adhesion in their mesenchymal lineage-specific propagation. Nevertheless, the use of non-human supplements in culture (xeno-free issue) in addition to the lack of control over unknown factors in the serum hampers the clinical transition of MSCs.

Methods

In this study, embryonic stem cell derived mesenchymal stem cells (ES-MSCs) were used owing to their scalable production, and they expressed a series of MSC markers same as adipose-derived MSCs. The affinity of the culture matrix was increased by combining fibronectin coating with its adjuvant peptide, gelatin, or both (FNGP) on tissue culture polystyrene to compare the regenerative, therapeutic activities of ES-MSCs with a cell binding plate as a commercial control.

Results

The FNGP culture plate promoted pivotal therapeutic functions of ES-MSCs as evidenced by their increased stemness as well as anti-inflammatory and proangiogenic effects in vitro. Indeed, after culturing on the FNGP plates, ES-MSCs efficiently rescued the necrotic damages in mouse ischemic hindlimb model.

Conclusions

This study suggests a potential solution by promoting the surface affinity of culture plates using a mixture of human fibronectin and its adjuvant PHSRN peptide in gelatin. The FNGP plate is expected to serve as an effective alternative for serum-free MSC expansion for bench to clinical transition.

Human ES-derived MSCs correct TNF-α-mediated alterations in a blood-brain barrier model

Background

Immune cell trafficking into the CNS is considered to contribute to pathogenesis in MS and its animal model, EAE. Disruption of the blood–brain barrier (BBB) is a hallmark of these pathologies and a potential target of therapeutics. Human embryonic stem cell-derived mesenchymal stem/stromal cells (hES-MSCs) have shown superior therapeutic efficacy, compared to bone marrow-derived MSCs, in reducing clinical symptoms and neuropathology of EAE. However, it has not yet been reported whether hES-MSCs inhibit and/or repair the BBB damage associated with neuroinflammation that accompanies EAE.

Methods

BMECs were cultured on Transwell inserts as a BBB model for all the experiments. Disruption of BBB models was induced by TNF-α, a pro-inflammatory cytokine that is a hallmark of acute and chronic neuroinflammation.

Results

Results indicated that hES-MSCs reversed the TNF-α-induced changes in tight junction proteins, permeability, transendothelial electrical resistance, and expression of adhesion molecules, especially when these cells were placed in direct contact with BMEC.

Conclusions

hES-MSCs and/or products derived from them could potentially serve as novel therapeutics to repair BBB disturbances in MS.

Electronic supplementary material

The online version of this article (10.1186/s12987-019-0138-5) contains supplementary material, which is available to authorized users.

The Plasticity of Mesenchymal Stem Cells in Regulating Surface HLA-I

A low surface expression level of human leukocyte antigen class I (HLA-I) ensures that the mesenchymal stem cells (MSCs) escape from the allogeneic recipients' immunological surveillance. Here, we discovered that both transcriptional and synthesis levels of HLA-I in MSCs increased continuously after interferon (IFN)-γ treatment, whereas interestingly, their surface HLA-I expression was downregulated after reaching an HLA-I surface expression peak. Microarray data indicated that the post-transcriptional process plays an important role in the downregulation of surface HLA-I. Further studies identified that IFN-γ-treated MSCs accelerated HLA-I endocytosis through a clathrin-independent dynamin-dependent endocytosis pathway. Furthermore, cells that have self-downregulated surface HLA-I expression elicit a weaker immune response than they previously could. Thus uncovering the plasticity of MSCs in the regulation of HLA-I surface expression would reveal insights into the membrane transportation events leading to the maintenance of low surface HLA-I expression, providing more evidence for selecting and optimizing low-immunogenic MSCs to improve the therapeutic efficiency.

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hESC-MSCs have the plasticity of maintaining low HLA-I expression on cell surface

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hESC-MSCs downregulate the surface HLA-I expression through endocytosis of HLA-I

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hESC-MSCs with lower HLA-I surface expression induce weaker MLR and slighter DTH

Secretome of Aggregated Embryonic Stem Cell-Derived Mesenchymal Stem Cell Modulates the Release of Inflammatory Factors in Lipopolysaccharide-Induced Peripheral Blood Mononuclear Cells

Background:

Bone marrow mesenchymal stem cells (BM-MSCs) have emerged as a potential therapy for various inflammatory diseases. Because of some limitations, several recent studies have suggested the use of embryonic stem cell-derived MSCs (ESC-MSCs) as an alternative for BM-MSCs. Some of the therapeutic effects of the ESC-MSCs are related to the secretion of a broad array of cytokines and growth factors, known as secretome. Harnessing this secretome for therapeutic applications requires the optimization of production of secretary molecules. It has been shown that aggregation of MSCs into 3D spheroids, as a preconditioning strategy, can enhance immunomodulatory potential of such cells. In this study, we investigated the effect of secretome derived from human ESC-MSCs (hESC-MSCs) spheroids on secretion of IL-1β, IL-10, and tumor necrosis factor α (TNF-α) from lipopolysaccharide (LPS)-induced peripheral blood mononuclear cells (PBMCs).

Methods:

In the present study, after immunophenotyping and considering mesodermal differentiation of hESC-MSCs, the cells were non-adherently grown to prepare 3D aggregates, and then conditioned medium or secretome was extracted from the cultures. Afterwards, the anti-inflammatory effects of the secretome were assessed in an in vitro model of inflammation.

Results:

Results from this study showed that aggregate-prepared secretome from hESC-MSCs was able to significantly decrease the secretion of TNF-α (301.7 ± 5.906, p < 0.0001) and IL-1β (485.2 ± 48.38, p < 0.001) from LPS-induced PBMCs as the indicators of inflammation, in comparison with adherent culture-prepared secretome (TNF-α: 166.6 ± 8.04, IL-1β: 125.2 ± 2.73).

Conclusion:

Our study indicated that cell aggregation can be an appropriate strategy to increase immunomodulatory characteristics of hESC-MSCs.

Modulation of human allogeneic and syngeneic pluripotent stem cells and immunological implications for transplantation

Tissues derived from induced pluripotent stem cells (iPSCs) are a promising source of cells for building various regenerative medicine therapies; from simply transplanting cells to reseeding decellularized organs to reconstructing multicellular tissues. Although reprogramming strategies for producing iPSCs have improved, the clinical use of iPSCs is limited by the presence of unique human leukocyte antigen (HLA) genes, the main immunologic barrier to transplantation. In order to overcome the immunological hurdles associated with allogeneic tissues and organs, the generation of patient-histocompatible iPSCs (autologous or HLA-matched cells) provides an attractive platform for personalized medicine. However, concerns have been raised as to the fitness, safety and immunogenicity of iPSC derivatives because of variable differentiation potential of different lines and the identification of genetic and epigenetic aberrations that can occur during the reprogramming process. In addition, significant cost and regulatory barriers may deter commercialization of patient specific therapies in the short-term. Nonetheless, recent studies provide some evidence of immunological benefit for using autologous iPSCs. Yet, more studies are needed to evaluate the immunogenicity of various autologous and allogeneic human iPSC-derived cell types as well as test various methods to abrogate rejection. Here, we present perspectives of using allogeneic vs. autologous iPSCs for transplantation therapies and the advantages and disadvantages of each related to differentiation potential, immunogenicity, genetic stability and tumorigenicity. We also review the current literature on the immunogenicity of syngeneic iPSCs and discuss evidence that questions the feasibility of HLA-matched iPSC banks. Finally, we will discuss emerging methods of abrogating or reducing host immune responses to PSC derivatives.

A therapy-grade protocol for differentiation of pluripotent stem cells into mesenchymal stem cells using platelet lysate as supplement

Introduction

Mesenchymal stem cells (MSCs) are a promising source of cells for regenerative therapies. Although they can be isolated easily from several tissues, cell expansion is limited since their properties are lost with successive passages. Hence, pluripotent derived MSCs (PD-MSCs) arise as a suitable alternative for MSC production. Nevertheless, at present, PD-MSC derivation protocols are either expensive or not suitable for clinical purposes.

Methods

In this work we present a therapy-grade, inexpensive and simple protocol to derive MSCs from pluripotent stem cells (PSCs) based on the use of platelet lysate (PL) as medium supplement.

Results

We showed that the PD-MSC_PL expressed multiple MSC markers, including CD90, CD73, CD105, CD166, and CD271, among others. These cells also show multilineage differentiation ability and immunomodulatory effects on pre-stimulated lymphocytes. Thorough characterization of these cells showed that a PD-MSC_PL resembles an umbilical cord (UC) MSC and differs from a PSC in surface marker and extracellular matrix proteins and integrin expression. Moreover, the OCT-4 promoter is re-methylated with mesenchymal differentiation comparable with the methylation levels of UC-MSCs and fibroblasts. Lastly, the use of PL-supplemented medium generates significantly more MSCs than the use of fetal bovine serum.

Conclusions

This protocol can be used to generate a large amount of PD-MSCs with low cost and is compatible with clinical therapies.

Electronic supplementary material

The online version of this article (doi:10.1186/scrt540) contains supplementary material, which is available to authorized users.

Repair of cartilage defects in arthritic tissue with differentiated human embryonic stem cells

Chondrocytes have been generated in vitro from a range of progenitor cell types and by a number of strategies. However, achieving reconstitution of actual physiologically relevant, appropriately-laminated cartilage in situ that would be applicable to conditions, such as arthritis and cartilage degeneration remains elusive. This lack of success is multifactorial and includes limited cell source, decreased proliferation rate of mature chondrocytes, lack of maintenance of phenotype, reduced matrix synthesis, and poor integration with host tissue. We report an efficient approach for deriving mesenchymal chondroprogenitor cells from human embryonic stem cells. These cells generated tissue containing cartilage-specific matrix proteins that integrated in situ in a partial-thickness defect in ex vivo articular cartilage harvested from human arthritic joints. Given that stem cells provide a virtually inexhaustible supply of starting material and that our technique is easily scalable, cartilaginous tissue primed and grafted in this manner could be suitable for clinical translation.

Excess of O-linked N-acetylglucosamine modifies human pluripotent stem cell differentiation

O-linked-N-acetylglucosamine (O-GlcNAc), a post translational modification, has emerged as an important cue in controlling key cell mechanisms. Here, we investigate O-GlcNAc's role in the maintenance and differentiation of human pluripotent stem cells (hPSC). We reveal that protein expression of O-GlcNAc transferase and hydrolase both decreases during hPSC differentiation. Upregulating O-GlcNAc with O-GlcNAc hydrolase inhibitors has no significant effect on either the maintenance of pluripotency in hPSC culture, or the loss of pluripotency in differentiating hPSC. However, in spontaneously differentiating hPSC, excess O-GlcNAc alters the expression of specific lineage markers: decrease of ectoderm markers (PAX6 by 53-88%, MSX1 by 26-49%) and increase of adipose-related mesoderm markers (PPARγ by 28-100%, C/EBPα by 46-135%). All other lineage markers tested (cardiac, visceral-endoderm, trophectoderm) remain minimally affected by upregulated O-GlcNAc. Interestingly, we also show that excess O-GlcNAc triggers a feedback mechanism that increases O-GlcNAc hydrolase expression by 29-91%. To the best of our knowledge, this is the first report demonstrating that excess O-GlcNAc does not affect hPSC pluripotency in undifferentiated maintenance cultures; instead, it restricts the hPSC differentiation towards specific cell lineages. These data will be useful for developing targeted differentiation protocols and aid in understanding the effects of O-GlcNAc on hPSC differentiation.

Therapeutic potential of human induced pluripotent stem cell-derived mesenchymal stem cells in mice with lethal fulminant hepatic failure

Large-scale production and noninvasive methods for harvesting mesenchymal stem cells (MSCs), particularly in elderly individuals, has prompted researchers to find new patient-specific sources for MSCs in regenerative medicine. This study aims to produce MSCs from human induced pluripotent stem cells (hiPSCs) and to evaluate their therapeutic effects in a CCl4-induced mouse model of fulminant hepatic failure (FHF). hiPSC-MSCs have shown MSC morphology, antigen profile and differentiation capabilities, and improved hepatic function in our model. hiPSC-MSC-transplanted animals provide significant benefit in terms of survival, serum LDH, total bilirubin, and lipid peroxidation. hiPSC-MSC therapy resulted in a one-third reduction of histologic activity index and a threefold increase in the number of proliferating hepatocytes. This was accompanied by a significant decrease in the expression levels of collagen type I, Mmp13, Mmp2, and Mmp9 genes and increase in Timp1 and Timp2 genes in transplanted groups. hiPSC-MSCs secreted hepatocyte growth factor (HGF) in vitro and also expressed HGF in evaluated liver sections. Similar results were observed with human bone marrow (hBM)-derived MSCs. In conclusion, our results have demonstrated that hiPSC-MSCs might be valuable appropriate alternatives for hBM-MSCs in FHF liver repair and support liver function by cell therapy with a large-scale production capacity, patient-specific nature, and no invasive MSC harvesting.

Epigenetic reprogramming of mesenchymal stem cells

Mesenchymal stem cells (MSCs) are multipotent stem cells of mesodermal origin that can be isolated from various sources and induced into different cell types. Although MSCs possess immune privilege and are more easily obtained than embryonic stem cells, their propensity to tumorigenesis has not been fully explored. Epigenomic changes in DNA methylation and chromatin structure have been hypothesized to be critical in the determination of lineage-specific differentiation and tumorigenesis of MSCs, but this has not been formally proven. We applied a targeted DNA methylation method to methylate a Polycomb group protein-governed gene, Trip10, in MSCs, which accelerated the cell fate determination of MSCs. In addition, targeted methylation of HIC1 and RassF1A, both tumor suppressor genes, transformed MSCs into tumor stem cell-like cells. This new method will allow better control of the differentiation of MSCs and their use in downstream applications.

Concise review: Induced pluripotent stem cell-derived mesenchymal stem cells: progress toward safe clinical products

Adult stem cell therapies have provided success for more than 50 years, through reconstitution of the hematopoietic system using bone marrow, umbilical cord blood, and mobilized peripheral blood transplantation. Mesenchymal stem cell (MSC)-mediated therapy is a fast-growing field that has proven safe and effective in the treatment of various degenerative diseases and tissue injuries. Since the first derivation of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), there has been impressive progress toward developing safe clinical applications from PSCs. Recent successes in transgene-free iPSC reprogramming have brought attention to the potential of clinical applications of these pluripotent cells, but key hurdles must be overcome, which are discussed in this review. Looking to the future, it could be advantageous to derive MSC from iPSC or human ESC in cases where genetic engineering is needed, since in the PSCs, clones with "safe harbor" vector integration could be selected, expanded, and differentiated. Here, we describe the status of the progress of the use of MSC and PSCs in clinical trials and analyze the challenges that should be overcome before iPSC-derived MSC therapy can be used widely in the clinic.

Human embryonic stem cell-derived mesenchymal stromal cells

Mesenchymal stromal cells (MSCs) originally isolated from marrow have multipotent differentiation potential and favorable immunomodulatory and anti-inflammatory properties that make them very attractive for regenerative cellular therapy. Cells with similar phenotypic characteristics have now been derived from almost all fetal, neonatal, and adult tissues; furthermore, more recently similar cells have also been generated from human embryonic stem cells (ESCs). Generation of MSCs from human ESCs provides an opportunity to study the developmental biology of human mesenchymal lineage generation in vitro. Generation of bone and cartilage from human ESC-derived MSCs and their functional characterization, both in vitro and in vivo, is also an active area of investigation as ESCs could provide an unlimited source of MSCs for potential repair of bone and cartilage defects. MSCs from adult sources are being investigated in numerous Phase I-III clinical trials for a wide variety of indications, mainly based on their immunomodulatory properties. Our group and others have shown MSCs derived from human ESCs possess immunomodulatory properties similar to marrow-derived MSCs. Immunomodulatory properties of ESC-derived MSCs could prove to be highly valuable for their potential clinical applications in the future as derivatives of human ESCs have already entered clinical arena in the context of Phase I clinical trials.

Mesenchymal-like stem cells derived from human parthenogenetic embryonic stem cells

Human parthenogenetic embryonic stem cells (hpESCs) established from artificially activated oocytes have a wider immune-matching ability because of their homozygosity in the major histocompatibility complex alleles. Whether these cells possess the differentiation capacity similar to regular human embryonic stem cells (hESCs) derived from fertilized eggs is unclear. The aims of this study were to determine whether hpESCs could be differentiated into multipotent mesenchymal stem cell (MSC)-like cells in vitro and then compare these cells with those derived from hESCs. MSC-like cells were obtained from both hpESCs and hESCs, which exhibited similar cell surface marker expression profiles. Further analyses revealed that cells derived from hpESCs possessed stronger osteogenic but weaker adipogenic potentials compared with cells derived from hESCs. This is the first work that demonstrates the differentiation of hpESCs into multipotent MSC-like cells. These hpESCs could be a potential source for cell-based therapies.

Stem cells in bone diseases: current clinical practice

INTRODUCTION

Bone is an obvious candidate tissue for stem cell therapy. This review provides an update of existing stem cell-based clinical treatments for bone pathologies.

SOURCES OF DATA

A systematic computerized literature search was conducted. The following databases were accessed on 10 February 2011: NIH clinical trials database, PubMed, Ovid and Cochrane Reviews.

AREAS OF AGREEMENT

Stem cell therapy offers new options for bone conditions, both acquired and inherited.

AREAS OF CONTROVERSY

There is still no agreement on the exact definition of 'mesenchymal stem cells'. Consequently, it is difficult to appreciate the effect of culture expansion and the feasibility of allogeneic transplantation.

GROWING POINTS

Based on the sound foundations of pre-clinical research, stem cell-based treatments and protocols have recently emerged.

AREAS TIMELY FOR DEVELOPING RESEARCH

Well-designed prospective clinical trials are needed in order to establish and develop stem cell therapy for bone diseases.

Stem cell-based strategies for the treatment of type 1 diabetes mellitus

IMPORTANCE OF THE FIELD

β-Cell regeneration and β-cell preservation are two promising therapeutic approaches for the management of patients with type 1 diabetes (T1D). Stem cell-based strategies to address the problems of shortage in β cells, autoimmune and alloimmune responses have become an area of intense study.

AREAS COVERED IN THIS REVIEW

This review focuses on the progress that has been made in obtaining functional, insulin-producing cells from various types of stem/progenitor cells, including the current knowledge on the immunomodulatory roles of hematopoietic stem cell and multipotent stromal cell in the therapies for T1D.

WHAT THE READER WILL GAIN

A broad overview of recent advancements in this field is provided. The hurdles that remain in the path of using stem cell-based strategies for the treatment of T1D and possible approaches to overcome these challenges are discussed.

TAKE HOME MESSAGE

Stem cell-based strategies hold great promise for the treatment of T1D. In spite of the progress that has been made over the last decade, a number of obstacles and concerns need to be cleared before widespread clinical application is possible. In particular, the mechanism of ESC and iPSC-derived β-cell maturation in vivo is poorly understood.