Rapid and Efficient Generation of Transgene-Free iPSC from a Small Volume of Cryopreserved Blood

Induced Pluripotent Stem Cells and Organoids in Advancing Neuropathology Research and Therapies

This review delves into the groundbreaking impact of induced pluripotent stem cells (iPSCs) and three-dimensional organoid models in propelling forward neuropathology research. With a focus on neurodegenerative diseases, neuromotor disorders, and related conditions, iPSCs provide a platform for personalized disease modeling, holding significant potential for regenerative therapy and drug discovery. The adaptability of iPSCs, along with associated methodologies, enables the generation of various types of neural cell differentiations and their integration into three-dimensional organoid models, effectively replicating complex tissue structures in vitro. Key advancements in organoid and iPSC generation protocols, alongside the careful selection of donor cell types, are emphasized as critical steps in harnessing these technologies to mitigate tumorigenic risks and other hurdles. Encouragingly, iPSCs show promising outcomes in regenerative therapies, as evidenced by their successful application in animal models.

Identification and Re-consent of Existing Cord Blood Donors for Creation of Induced Pluripotent Stem Cell Lines for Potential Clinical Applications

We aim to create a bank of clinical grade cord blood-derived induced pluripotent stem cell lines in order to facilitate clinical research leading to the development of new cellular therapies. Here we present a clear pathway toward the creation of such a resource, within a strong quality framework, and with the appropriate regulatory, government and ethics approvals, along with a dynamic follow-up and re-consent process of cord blood donors from the public BMDI Cord Blood Bank. Interrogation of the cord blood bank inventory and next generation sequencing was used to identify and confirm 18 donors with suitable HLA homozygous haplotypes. Regulatory challenges that may affect global acceptance of the cell lines, along with the quality standards required to operate as part of a global network, are being met by working in collaboration with bodies such as the International Stem Cell Banking Initiative (ISCBI) and the Global Alliance for iPSC Therapies (GAiT). Ethics approval was granted by an Institutional Human Research Ethics Committee, and government approval has been obtained to use banked cord blood for this purpose. New issues of whole-genome sequencing and the relevant donor safeguards and protections were considered with input from clinical genetics services, including the rights and information flow to donors, and commercialization aspects. The success of these processes has confirmed feasibility and utility of using banked cord blood to produce clinical-grade iPSC lines for potential cellular therapies.

Reactive Astrocytes Derived From Human Induced Pluripotent Stem Cells Suppress Oligodendrocyte Precursor Cell Differentiation

Astrocytes are instrumental in maintaining central nervous system (CNS) homeostasis and responding to injury. A major limitation of studying neurodegenerative diseases like multiple sclerosis (MS) is lack of human pathological specimens obtained during the acute stages, thereby relegating research to post-mortem specimens obtained years after the initiation of pathology. Rodent reactive astrocytes have been shown to be cytotoxic to neurons and oligodendrocytes but may differ from human cells, especially in diseases with genetic susceptibility. Herein, we purified human CD49f+ astrocytes from induced pluripotent stem cells derived from individual patient and control peripheral leukocytes. We compared TNF and IL1α stimulated human reactive astrocytes from seven persons with MS and six non-MS controls and show their transcriptomes are remarkably similar to those described in rodents. The functional effect of astrocyte conditioned media (ACM) was examined in a human oligodendrocyte precursor cell (OPC) line differentiation assay. ACM was not cytotoxic to the OPCs but robustly inhibited the myelin basic protein (MBP) reporter. No differences were seen between MS and control stimulated astrocytes at either the transcript level or in ACM mediated OPC suppression assays. We next used RNAseq to interrogate differentially expressed genes in the OPC lines that had suppressed differentiation from the human ACM. Remarkably, not only was OPC differentiation and myelin gene expression suppressed, but we observed induction of several immune pathways in OPCs exposed to the ACM. These data support the notion that reactive astrocytes can inhibit OPC differentiation thereby limiting their remyelination capacity, and that OPCs take on an immune profile in the context of inflammatory cues.

Creation of GMP-Compliant iPSCs From Banked Umbilical Cord Blood

Many clinical trials are in progress using cells derived from induced pluripotent stem cells (iPSC) for immunotherapies and regenerative medicine. The success of these new therapies is underpinned by the quality of the cell population used to create the iPSC lines, along with the creation of iPSCs in a fully Good Manufacturing Practice (GMP)-compliant environment such that they can be used safely and effectively in the clinical setting. Umbilical cord blood (CB) from public cord blood banks is an excellent source of starting material for creation of iPSCs. All CB units are manufactured under GMP-conditions, have been screened for infectious diseases, with known family and medical history of the donor. Furthermore, the HLA tissue typing is known, thereby allowing identification of CB units with homozygous HLA haplotypes. CB cells are naïve with less exposure to environmental insults and iPSC can be generated with high efficiency. We describe a protocol that can be adopted by those seeking to create clinical-grade iPSC from banked CB. This protocol uses a small volume of thawed CB buffy to first undergo ex-vivo expansion towards erythroid progenitor cells, which are then used for reprogramming using the CytoTune™-iPS 2.0 Sendai Reprogramming Kit. Resultant iPSC lines are tested to confirm pluripotency, genomic integrity, and stability. Cells are maintained in a feeder-free, xeno-free environment, using fully defined, commercially available reagents. Adoption of this protocol, with heed given to tips provided, allows efficient and robust creation of clinical-grade iPSC cell lines from small volumes of cryopreserved CB.

Stem cell-derived neurons reflect features of protein networks, neuropathology, and cognitive outcome of their aged human donors

We have generated a controlled and manipulable resource that captures genetic risk for Alzheimer's disease: iPSC lines from 53 individuals coupled with RNA and proteomic profiling of both iPSC-derived neurons and brain tissue of the same individuals. Data collected for each person include genome sequencing, longitudinal cognitive scores, and quantitative neuropathology. The utility of this resource is exemplified here by analyses of neurons derived from these lines, revealing significant associations between specific Aβ and tau species and the levels of plaque and tangle deposition in the brain and, more importantly, with the trajectory of cognitive decline. Proteins and networks are identified that are associated with AD phenotypes in iPSC neurons, and relevant associations are validated in brain. The data presented establish this iPSC collection as a resource for investigating person-specific processes in the brain that can aid in identifying and validating molecular pathways underlying AD.

An Overview on Promising Somatic Cell Sources Utilized for the Efficient Generation of Induced Pluripotent Stem Cells

Human induced Pluripotent Stem Cells (iPSCs) have enormous potential in understanding developmental biology, disease modeling, drug discovery, and regenerative medicine. The initial human iPSC studies used fibroblasts as a starting cell source to reprogram them; however, it has been identified to be a less appealing somatic cell source by numerous studies due to various reasons. One of the important criteria to achieve efficient reprogramming is determining an appropriate starting somatic cell type to induce pluripotency since the cellular source has a major influence on the reprogramming efficiency, kinetics, and quality of iPSCs. Therefore, numerous groups have explored various somatic cell sources to identify the promising sources for reprogramming into iPSCs with different reprogramming factor combinations. This review provides an overview of promising easily accessible somatic cell sources isolated in non-invasive or minimally invasive manner such as keratinocytes, urine cells, and peripheral blood mononuclear cells used for the generation of human iPSCs derived from healthy and diseased subjects. Notably, iPSCs generated from one of these cell types derived from the patient will offer ethical and clinical advantages. In addition, these promising somatic cell sources have the potential to efficiently generate bona fide iPSCs with improved reprogramming efficiency and faster kinetics. This knowledge will help in establishing strategies for safe and efficient reprogramming and the generation of patient-specific iPSCs from these cell types.

Induced pluripotent stem cell (iPSC) line (ZZUNEUi009-A) from a healthy female individual

Induced pluripotent stem cells (iPSCs) can be used to generate different types of somatic cells in vitro and are a useful tool for investigating drug and disease mechanisms. Here, we generated human induced pluripotent stem cell (iPSC) line ZZUNEUi009-A from an apparently healthy 28-year-old female by reprogramming peripheral blood mononuclear cells with non-integrating vector. The generated iPSCs was pluripotent, maintained a stable karyotype, and could generate the three layers (ectoderm, mesoderm, and endoderm) in vitro.

Generation of a hiPSC line ZZUNEUi017-A from a patient with dilated cardiomyopathy caused by mutation in TTN

Dilated cardiomyopathy (DCM) is the commonest type of cardiomyopathy. In this study, peripheral blood mononuclear cells (PBMCs) were isolated from a DCM patient with the p. Glu12513fs(c.37537delG) mutation in TTN and were reprogrammed to human induced pluripotent stem cells (iPSCs). The ZZUNEUi017-A iPSC line expressed pluripotency markers, exhibiting a normal male karyotype (46, XY) and demonstrating differentiation potential into three germ layers in vitro.

Umbilical Cord Tissue as a Source of Young Cells for the Derivation of Induced Pluripotent Stem Cells Using Non-Integrating Episomal Vectors and Feeder-Free Conditions

The clinical application of induced pluripotent stem cells (iPSC) needs to balance the use of an autologous source that would be a perfect match for the patient against any safety or efficacy issues that might arise with using cells from an older patient or donor. Drs. Takahashi and Yamanaka and the Office of Cellular and Tissue-based Products (PMDA), Japan, have had concerns over the existence of accumulated DNA mutations in the cells of older donors and the possibility of long-term negative effects. To mitigate the risk, they have chosen to partner with the Umbilical Cord (UC) banks in Japan to source allogeneic-matched donor cells. Production of iPSCs from UC blood cells (UCB) has been successful; however, reprogramming blood cells requires cell enrichment with columns or flow cytometry and specialized growth media. These requirements add to the cost of production and increase the manipulation of the cells, which complicates the regulatory approval process. Alternatively, umbilical cord tissue mesenchymal stromal cells (CT-MSCs) have the same advantage as UCB cells of being a source of young donor cells. Crucially, CT-MSCs are easier and less expensive to harvest and grow compared to UCB cells. Here, we demonstrate that CT-MSCs can be easily isolated without expensive enzymatic treatment or columns and reprogramed well using episomal vectors, which allow for the removal of the reprogramming factors after a few passages. Together the data indicates that CT-MSCs are a viable source of donor cells for the production of clinical-grade, patient matched iPSCs.

An Efficient Culture Method of CD3-Positive T Cells from Human Cryopreserved Buffy Coat Specimens

Context: In the National Cerebral and Cardiovascular Center (NCVC) Biobank, buffy coats have been collected from patients and stored with cryoprotective agents as a possible source for viable blood cells, using cost-efficient methods for storage. However, whether viable cells for in vitro studies can be recovered from these biospecimens has not been verified. Objective: To investigate whether T cells can be collected and expanded as viable cells from cryopreserved human buffy coats. Design: After thawing of cryopreserved buffy coat specimens, CD3-positive cells were isolated from the cell suspension using a leukocyte separation filter coated with an anti-CD3 antibody, and the filter-attached cells were cultured in T cell culture medium. To analyze the characteristics of these cultured cells, histocytological analyses of Giemsa staining, immunocytochemical (ICC) staining for CD3, and flow cytometry for CD3 in live cells were conducted. Results: A few days after starting cell culture, cell clusters were observed, and they gradually grew in size. Using Giemsa staining, the expanded cells were found to be ∼15 μm in diameter, having round nuclei, a high nucleus/cytoplasm ratio, and cytoplasm stained light blue, which is characteristic of lymphocytes. From ICC staining, these cells were CD3 positive, a pan-T cell marker among lymphocytes. Furthermore, CD3 immunoreactivity in live cells was detected in a flow cytometry assay, though that for CD19 was not detected, which is a marker of pan-B cells. Conclusions: These results suggest that T cells can be expanded from buffy coats cryopreserved at -180°C as an adequate method of NCVC Biobank, highlighting these biospecimens as a possible useful source for future in vitro studies.

High-Throughput Image Cytometry Detection Method for CAR-T Transduction, Cell Proliferation, and Cytotoxicity Assays

Chimeric antigen receptor (CAR)-T cell therapy has drawn much attention due to its recent clinical success in B-cell malignancies. In general, the CAR-T cell discovery process consists of CAR identification, T-cell activation, transduction, and expansion, as well as assessment of CAR-T cytotoxicity. The current evaluation methods for the CAR-T discovery process can be time-consuming, low-throughput and requires the preparation of multiple sacrificial samples in order to produce kinetic data. In this study, we employed the use of a plate-based image cytometer to monitor anti-CAIX (carbonic anhydrase IX) G36 CAR-T generation and assess its cytotoxic potency of direct and selective killing against CAIX⁺ SKRC-59 human renal cell carcinoma cells. The transduction efficiency and cytotoxicity results were analyzed using image cytometry and compared directly to flow cytometry and Chromium 51 (⁵¹ Cr) release assays, showing that image cytometry was comparable against these conventional methods. Image cytometry method streamlines the assays required during the CAR-T cell discovery process by analyzing a plate of T cells from CAR-T generation to in vitro functional assays with minimum disruption. The proposed method can reduce assay time and uses less cell samples by imaging and analyze the same plate over time without the need to sacrifice any cells. The ability to monitor kinetic data can allow additional insights into the behavior and interaction between CAR-T and target tumor cells. © 2020 International Society for Advancement of Cytometry.

Targeting cell plasticity for regeneration: From in vitro to in vivo reprogramming

The discovery of induced pluripotent stem cells (iPSCs), reprogrammed to pluripotency from somatic cells, has transformed the landscape of regenerative medicine, disease modelling and drug discovery pipelines. Since the first generation of iPSCs in 2006, there has been enormous effort to develop new methods that increase reprogramming efficiency, and obviate the need for viral vectors. In parallel to this, the promise of in vivo reprogramming to convert cells into a desired cell type to repair damage in the body, constitutes a new paradigm in approaches for tissue regeneration. This review article explores the current state of reprogramming techniques for iPSC generation with a specific focus on alternative methods that use biophysical and biochemical stimuli to reduce or eliminate exogenous factors, thereby overcoming the epigenetic barrier towards vector-free approaches with improved clinical viability. We then focus on application of iPSC for therapeutic approaches, by giving an overview of ongoing clinical trials using iPSCs for a variety of health conditions and discuss future scope for using materials and reagents to reprogram cells in the body.

Robust and highly efficient hiPSC generation from patient non-mobilized peripheral blood-derived CD34+ cells using the auto-erasable Sendai virus vector

BACKGROUND

Disease modeling with patient-derived induced pluripotent stem cells (iPSCs) is a powerful tool for elucidating the mechanisms underlying disease pathogenesis and developing safe and effective treatments. Patient peripheral blood (PB) cells are used for iPSC generation in many cases since they can be collected with minimum invasiveness. To derive iPSCs that lack immunoreceptor gene rearrangements, hematopoietic stem and progenitor cells (HSPCs) are often targeted as the reprogramming source. However, the current protocols generally require HSPC mobilization and/or ex vivo expansion owing to their sparsity at the steady state and low reprogramming efficiencies, making the overall procedure costly, laborious, and time-consuming.

METHODS

We have established a highly efficient method for generating iPSCs from non-mobilized PB-derived CD34+ HSPCs. The source PB mononuclear cells were obtained from 1 healthy donor and 15 patients and were kept frozen until the scheduled iPSC generation. CD34+ HSPC enrichment was done using immunomagnetic beads, with no ex vivo expansion culture. To reprogram the CD34+-rich cells to pluripotency, the Sendai virus vector SeVdp-302L was used to transfer four transcription factors: KLF4, OCT4, SOX2, and c-MYC. In this iPSC generation series, the reprogramming efficiencies, success rates of iPSC line establishment, and progression time were recorded. After generating the iPSC frozen stocks, the cell recovery and their residual transgenes, karyotypes, T cell receptor gene rearrangement, pluripotency markers, and differentiation capability were examined.

RESULTS

We succeeded in establishing 223 iPSC lines with high reprogramming efficiencies from 15 patients with 8 different disease types. Our method allowed the rapid appearance of primary colonies (~ 8 days), all of which were expandable under feeder-free conditions, enabling robust establishment steps with less workload. After thawing, the established iPSC lines were verified to be pluripotency marker-positive and of non-T cell origin. A majority of the iPSC lines were confirmed to be transgene-free, with normal karyotypes. Their trilineage differentiation capability was also verified in a defined in vitro assay.

CONCLUSION

This robust and highly efficient method enables the rapid and cost-effective establishment of transgene-free iPSC lines from a small volume of PB, thus facilitating the biobanking of patient-derived iPSCs and their use for the modeling of various diseases.

Adapting Cord Blood Collection and Banking Standard Operating Procedures for HLA-Homozygous Induced Pluripotent Stem Cells Production and Banking for Clinical Application

In this article, we will discuss the main aspects to be considered to define standard operation procedures (SOPs) for the creation of an induced pluripotent stem cell (iPSC) bank using cord blood (CB)-or similar cell type-bank guidelines for clinical aims. To do this, we adapt the pre-existing SOP for CB banking that can be complementary for iPSCs. Some aspects of iPSC manufacturing and the particular nature of these cells call for special attention, such as the potential multiple applications of the cells, proper explanation to the donor for consent of use, the genomic stability and the risk of genetic privacy disclosure. Some aspects of the iPSC SOP are solidly established by CB banking procedures, other procedures have good consensus in the scientific and medical community, while others still need to be further debated and settled. Given the international sharing vocation of iPSC banking, there is an urgent need by scientists, clinicians and regulators internationally to harmonize standards and allow future sample interchange between many iPSC bank initiatives that are springing up worldwide.

Studying and modulating schizophrenia-associated dysfunctions of oligodendrocytes with patient-specific cell systems

Postmortem studies in patients with schizophrenia (SCZ) have revealed deficits in myelination, abnormalities in myelin gene expression and altered numbers of oligodendrocytes in the brain. However, gaining mechanistic insight into oligodendrocyte (OL) dysfunction and its contribution to SCZ has been challenging because of technical hurdles. The advent of individual patient-derived human-induced pluripotent stem cells (hiPSCs), combined with the generation of in principle any neuronal and glial cell type, including OLs and oligodendrocyte precursor cells (OPCs), holds great potential for understanding the molecular basis of the aetiopathogenesis of genetically complex psychiatric diseases such as SCZ and could pave the way towards personalized medicine. The development of neuronal and glial co-culture systems now appears to enable the in vitro study of SCZ-relevant neurobiological endophenotypes, including OL dysfunction and myelination, with unprecedented construct validity. Nonetheless, the meaningful stratification of patients before the subsequent functional analyses of patient-derived cell systems still represents an important bottleneck. Here, to improve the predictive power of ex vivo disease modelling we propose using hiPSC technology to focus on representatives of patient subgroups stratified for genomic and/or phenomic features and neurobiological cell systems. Therefore, this review will outline the evidence for the involvement of OPCs/OLs in SCZ in the context of their proposed functions, including myelination and axon support, the implications for hiPSC-based cellular disease modelling and potential strategies for patient selection.

Optimizing the method for generation of integration-free induced pluripotent stem cells from human peripheral blood

Background

Generation of induced pluripotent stem cells (iPSCs) from human peripheral blood provides a convenient and low-invasive way to obtain patient-specific iPSCs. The episomal vector is one of the best approaches for reprogramming somatic cells to pluripotent status because of its simplicity and affordability. However, the efficiency of episomal vector reprogramming of adult peripheral blood cells is relatively low compared with cord blood and bone marrow cells.

Methods

In the present study, integration-free human iPSCs derived from peripheral blood were established via episomal technology. We optimized mononuclear cell isolation and cultivation, episomal vector promoters, and a combination of transcriptional factors to improve reprogramming efficiency.

Results

Here, we improved the generation efficiency of integration-free iPSCs from human peripheral blood mononuclear cells by optimizing the method of isolating mononuclear cells from peripheral blood, by modifying the integration of culture medium, and by adjusting the duration of culture time and the combination of different episomal vectors.

Conclusions

With this optimized protocol, a valuable asset for banking patient-specific iPSCs has been established.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0908-z) contains supplementary material, which is available to authorized users.

Chemically defined and growth-factor-free culture system for the expansion and derivation of human pluripotent stem cells

The large-scale and cost-effective production of quality-controlled human pluripotent stem cells (hPSCs) for use in cell therapy and drug discovery would ideally require a chemically defined xenobiotic-free culture system. Towards the development of such a system, costs associated with the use of recombinant proteins as supplements in basal culture media need to be reduced. Here, we describe a growth-factor-free culture medium that uses just three chemical compounds and a lower number of recombinant proteins than used in commercially available media. We show that the culture medium supports the long-term propagation of hPSCs, as confirmed by karyotype, the expression of pluripotency markers and the capacity to differentiate into cell types derived from the three embryonic germ layers. hPSCs growing in the medium were less dependent on glycolytic pathways than cells grown in medium containing growth factors. Moreover, the medium supported the generation of induced pluripotent stem cells derived from either human dermal fibroblasts or peripheral blood mononuclear cells. Our findings should facilitate the ongoing development of a completely xeno-free, chemically defined, synthetic culture system for hPSCs.

Age Is Relative-Impact of Donor Age on Induced Pluripotent Stem Cell-Derived Cell Functionality

Induced pluripotent stem cells (iPSCs) avoid many of the restrictions that hamper the application of human embryonic stem cells: limited availability of source material due to legal restrictions in some countries, immunogenic rejection and ethical concerns. Also, the donor’s clinical phenotype is often known when working with iPSCs. Therefore, iPSCs seem ideal to tackle the two biggest tasks of regenerative medicine: degenerative diseases with genetic cause (e.g., Duchenne’s muscular dystrophy) and organ replacement in age-related diseases (e.g., end-stage heart or renal failure), especially in combination with recently developed gene-editing tools. In the setting of autologous transplantation in elderly patients, donor age becomes a potentially relevant factor that needs to be assessed. Here, we review and critically discuss available data pertinent to the questions: How does donor age influence the reprogramming process and iPSC functionality? Would it even be possible to reprogram senescent somatic cells? How does donor age affect iPSC differentiation into specialised cells and their functionality? We also identify research needs, which might help resolve current unknowns. Until recently, most hallmarks of ageing were attributed to an accumulation of DNA damage over time, and it was thus expected that DNA damage from a somatic cell would accumulate in iPSCs and the cells derived from them. In line with this, a decreased lifespan of cloned organisms compared with the donor was also observed in early cloning experiments. Therefore, it was questioned for a time whether iPSC derived from an old individual’s somatic cells would suffer from early senescence and, thus, may not be a viable option either for disease modelling nor future clinical applications. Instead, typical signs of cellular ageing are reverted in the process of iPSC reprogramming, and iPSCs from older donors do not show diminished differentiation potential nor do iPSC-derived cells from older donors suffer early senescence or show functional impairments when compared with those from younger donors. Thus, the data would suggest that donor age does not limit iPSC application for modelling genetic diseases nor regenerative therapies. However, open questions remain, e.g., regarding the potential tumourigenicity of iPSC-derived cells and the impact of epigenetic pattern retention.

Stem cell contributions to neurological disease modeling and personalized medicine

Human induced pluripotent stem cells (iPSCs) represent a revolutionary tool for disease modeling and drug discovery. The generation of tissue-relevant cell types exhibiting a patient's genetic and molecular background offers the ability to develop individual and effective therapies. In this review, we present some major achievements in the neuroscience field using iPSCs and discuss promising perspectives in personalized medicine. In addition to disease modeling, the understanding of the cellular and molecular basis of neurological disorders is explored, including the discovery of new targets and potential drugs. Ultimately, we highlight how iPSC technology, together with genome editing approaches, may bring a deep impact on pre-clinical trials by reducing costs and increasing the success of treatments in a personalized fashion.

Stem cells and genome editing: approaches to tissue regeneration and regenerative medicine

Understanding the basis of regeneration of each tissue and organ, and incorporating this knowledge into clinical treatments for degenerative tissues and organs in patients, are major goals for researchers in regenerative biology. Here we provide an overview of current work, from high-regeneration animal models, to stem cell-based culture models, transplantation technologies, large-animal chimeric models, and programmable nuclease-based genome-editing technologies. Three-dimensional culture generating organoids, which represents intact tissue/organ identity including cell fate and morphology are getting more general approaches in the fields by taking advantage of embryonic stem cells, induced pluripotent stem cells and adult stem cells. The organoid culture system potentially has profound impact on the field of regenerative medicine. We also emphasize that the large animal model, in particular pig model would be a hope to manufacture humanized organs in in vivo empty (vacant) niche, which now potentially allows not only appropriate cell fate identity but nearly the same property as human organs in size. Therefore, integrative and collaborative researches across different fields might be critical to the aims needed in clinical trial.

Cord blood cell-derived iPSCs as a new candidate for chondrogenic differentiation and cartilage regeneration

Background

The native articular cartilage lacks the ability to heal. Currently, ex vivo expanded chondrocytes or bone marrow-derived mesenchymal stem cells are used to regenerate the damaged cartilage. With unlimited self-renewal ability and multipotency, human induced pluripotent stem cells (hiPSCs) have been highlighted as a new replacement cell source for cartilage repair. Still, further research is needed on cartilage regeneration using cord blood mononuclear cell-derived hiPSCs (CBMC-hiPSCs).

Methods

Human iPSCs were generated from CBMCs using the Sendai virus. The characterization of CBMC-hiPSCs was performed by various assays. Embryonic bodies (EBs) were obtained using CBMC-hiPSCs, and outgrowth cells were induced by plating the EBs onto a gelatin-coated plate. Expanded outgrowth cells were detached and dissociated for chondrogenic differentiation. Outgrowth cells were differentiated into chondrogenic lineage with pellet culture. Chondrogenic pellets were maintained for 30 days. The quality of chondrogenic pellets was evaluated using various staining and genetic analysis of cartilage-specific markers.

Results

Reprogramming was successfully done using CBMCs. CBMC-hiPSCs (n = 3) showed high pluripotency and normal karyotype. Chondrogenic pellets were generated from the outgrowth cells derived from CBMC-hiPSC EBs. The generated chondrogenic pellets showed high expression of chondrogenic genetic markers such as ACAN, COMP, COL2A1, and SOX9. The production of extracellular matrix (ECM) proteins was confirmed by safranin O, alcian blue and toluidine blue staining. Expression of collagen type II and aggrecan was detected in the accumulated ECM by immunohistological staining. Chondrogenic pellets showed low expression of fibrotic and hypertrophic cartilage marker, collagen type I and X.

Conclusions

This study reveals the potential of CBMC-hiPSCs as a promising candidate for cartilage regeneration.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-017-0477-6) contains supplementary material, which is available to authorized users.

Choices for Induction of Pluripotency: Recent Developments in Human Induced Pluripotent Stem Cell Reprogramming Strategies

The ability to generate human induced pluripotent stem cells (iPSCs) from somatic cells provides tremendous promises for regenerative medicine and its use has widely increased over recent years. However, reprogramming efficiencies remain low and chromosomal instability and tumorigenic potential are concerns in the use of iPSCs, especially in clinical settings. Therefore, reprogramming methods have been under development to generate safer iPSCs with higher efficiency and better quality. Developments have mainly focused on the somatic cell source, the cocktail of reprogramming factors, the delivery method used to introduce reprogramming factors and culture conditions to maintain the generated iPSCs. This review discusses the developments on these topics and briefly discusses pros and cons of iPSCs in comparison with human embryonic stem cells generated from somatic cell nuclear transfer.

Blood Derived Induced Pluripotent Stem Cells (iPSCs): Benefits, Challenges and the Road Ahead

Since the creation of induced Pluripotent Stem Cells (iPSCs) ten years ago, hundreds of publications have demonstrated their considerable impact on disease modeling and therapy. In this commentary, we will summarize key milestones, benefits and challenges in the iPSC field. Furthermore, we will highlight blood as an effective and easily accessible source for patient-specific iPSCs derivation in the context of work done in our laboratory and others.

Choices for Induction of Pluripotency: Recent Developments in Human Induced Pluripotent Stem Cell Reprogramming Strategies

The ability to generate human induced pluripotent stem cells (iPSCs) from somatic cells provides tremendous promises for regenerative medicine and its use has widely increased over recent years. However, reprogramming efficiencies remain low and chromosomal instability and tumorigenic potential are concerns in the use of iPSCs, especially in clinical settings. Therefore, reprogramming methods have been under development to generate safer iPSCs with higher efficiency and better quality. Developments have mainly focused on the somatic cell source, the cocktail of reprogramming factors, the delivery method used to introduce reprogramming factors and culture conditions to maintain the generated iPSCs. This review discusses the developments on these topics and briefly discusses pros and cons of iPSCs in comparison with human embryonic stem cells generated from somatic cell nuclear transfer.

Generation of iPSCs as a Pooled Culture Using Magnetic Activated Cell Sorting of Newly Reprogrammed Cells

Although significant advancement has been made in the induced pluripotent stem cell (iPSC) field, current methods for iPSC derivation are labor intensive and costly. These methods involve manual selection, expansion, and characterization of multiple clones for each reprogrammed cell sample and therefore significantly hampers the feasibility of studies where a large number of iPSCs need to be derived. To develop higher throughput iPSC reprogramming methods, we generated iPSCs as a pooled culture using rigorous cell surface pluripotent marker selection with TRA-1-60 or SSEA4 antibodies followed by Magnetic Activated Cell Sorting (MACS). We observed that pool-selected cells are similar or identical to clonally derived iPSC lines from the same donor by all criteria examined, including stable expression of endogenous pluripotency genes, normal karyotype, loss of exogenous reprogramming factors, and in vitro spontaneous and lineage directed differentiation potential. This strategy can be generalized for iPSC generation using both integrating and non-integrating reprogramming methods. Our studies provide an attractive alternative to clonal derivation of iPSCs using rigorously selected cell pools and is amenable to automation.

Automated, high-throughput derivation, characterization and differentiation of induced pluripotent stem cells

Induced pluripotent stem cells (iPSCs) are an essential tool for modeling how causal genetic variants impact cellular function in disease, as well as an emerging source of tissue for regenerative medicine. The preparation of somatic cells, their reprogramming and the subsequent verification of iPSC pluripotency are laborious, manual processes limiting the scale and reproducibility of this technology. Here we describe a modular, robotic platform for iPSC reprogramming enabling automated, high-throughput conversion of skin biopsies into iPSCs and differentiated cells with minimal manual intervention. We demonstrate that automated reprogramming and the pooled selection of polyclonal pluripotent cells results in high-quality, stable iPSCs. These lines display less line-to-line variation than either manually produced lines or lines produced through automation followed by single-colony subcloning. The robotic platform we describe will enable the application of iPSCs to population-scale biomedical problems including the study of complex genetic diseases and the development of personalized medicines.

Can cord blood banks transform into induced pluripotent stem cell banks?

The discovery of induced pluripotent stem cells (iPSCs) and the rapid evolution of clinically compliant protocols to generate such lines from a variety of tissue sources has raised the possibility that personalized medicine may be achievable in the near future. Several strategies to deliver iPSCs for iPSC-derived cell-based therapy have been proposed: one such model has been the cell-banking model, using processes developed by the cord blood industry. The cord blood industry has evolved primarily as a banking model in which units of cord blood harvested from discarded placenta are stored either in a public or a private cord blood bank for future use. The consideration of a cord blood--like banking model has been further spurred by the realization that this population of cells is an ideal starting sample to generate pluripotent cells. Spurred by these technological advances, major efforts are underway to develop a current Good Manufacturing Practice--compliant protocol to generate iPSCs from cord blood and to develop a haplobanking strategy. In this article, we discuss the issues that may affect such an effort.