Multilineage Potential Research Articles

Differentiation of human menstrual blood-derived endometrial mesenchymal stem cells into oocyte-like cells.

Human endometrial mesenchymal stem cells (EnSCs) derived from menstrual blood are a unique stem cell source. Evidence suggests that EnSCs exhibit a multi-lineage potential and have attracted extensive attention in regenerative medicine. However, the potential of EnSCs to differentiate into germline cells in vitro remains unclear. In this study, EnSCs were induced to differentiate into germ cells in a differentiation medium supplemented with 20% human follicular fluid. Our results demonstrated that EnSCs derived from human menstrual blood form oocyte-like cells and express germ cell markers. The induced cell aggregates contained not only oocyte-like structures but also cells expressing follicle stimulating hormone receptor and luteotropic hormone receptor, and produced estrogen and progesterone regulated by gonodatropin, suggesting that granulosa-like and theca-like cells were also induced. We further found that granulosa cells promote the development of oocyte-like cells and activate the induction of blastocyst-like structures derived from EnSCs. In conclusion, EnSCs may potentially represent an in vitro system for the investigation of human folliculogenesis.

Progress towards generation of human haematopoietic stem cells.

De novo generation of haematopoietic stem cells from different human pluripotent stem cell sources remains a high priority for haematology and regenerative medicine. At present, efficient derivation of functional haematopoietic stem cells with the capability for definitive in vivo engraftment and multi-lineage potential remains challenging. Here, we discuss recent progress and strategies to overcome obstacles that have thwarted past efforts. In addition, we review promising advances in the generation of mature blood lineages and the potential of induced pluripotent stem cells.

T-lymphoid progenitors - we know what they are, but know not what they may be.

An improved understanding of the biology underlying leukemogenesis, including the determination of the cells of leukemia origin, is of great importance as it can have immediate implications on patient treatment and management. The article by Riemke et al ([2016][1]) provides further evidence that a subgroup of acute myeloid leukemia (AML), the most common acute leukemia in adults, might arise from T‐lymphoid progenitor cells. This study not only supports that the lymphoid fate of early T‐cell progenitors is not yet fully stabilized but also shows that under oncogenic conditions, this multilineage plasticity potential of T‐lymphoid progenitors can lead to transdifferentiation into myeloid leukemia. While gene expression profiles suggest that approximately 5% of all AML cases originate from T‐lymphoid progenitors, novel treatment strategies targeting JAK2/STAT3 signaling might open new avenues for this AML cohort. [1]: #ref-7

Improved osteogenesis and upregulated immunogenicity in human placenta-derived mesenchymal stem cells primed with osteogenic induction medium.

BackgroundMesenchymal stem cells (MSCs) are widely used in cell-based therapy owing to their multilineage potential and low immunogenicity. However, low differentiation efficiency and unpredictable immunogenicity of allogeneic MSCs in vivo limit their success in therapeutic treatment. Herein, we evaluated the differentiation potential and immunogenicity of human placenta-derived MSCs manipulated with osteogenic priming and dedifferentiation process.MethodsMSCs from human placentas were subjected to osteogenic induction and then cultivated in osteogenic factor-free media; the obtained cell population was termed dedifferentiated mesenchymal stem cells (De-MSCs). De-MSCs were induced into osteo-, chondro- and adipo-differentiation in vitro. Cell proliferation was quantified by a Cell-Counting Kit-8 or tritiated thymidine ([3H]-TdR) incorporation. Meanwhile, the osteogenesis of De-MSCs in vivo was assayed by real-time PCR and histological staining. The expressions of stem cell markers and co-stimulatory molecules on De-MSCs and lymphocytes from primed BALB/c mouse with De-MSCs were determined by flow cytometry.ResultsDe-MSCs exhibited some properties similar to MSCs including multiple differentiation potential and hypoimmunogenicity. Upon re-osteogenic induction, De-MSCs exhibited higher differentiation capability than MSCs both in vitro and in vivo. Of note, De-MSCs had upregulated immunogenicity in association with their osteogenesis, reflected by the alternated expressions of co-stimulatory molecules on the surface and decreased suppression on T cell activation. Functionally, De-MSC-derived osteoblasts could prime lymphocytes of peripheral blood and spleen in BALB/c mice in vivo.ConclusionsThese data are of great significance for the potential application of De-MSCs as an alternative resource for regenerative medicine and tissue engineering. In order to avoid being rejected by the host during allogeneic De-MSC therapy, we suggest that immune intervention should be considered to boost the immune acceptance and integration because of the upregulated immunogenicity of De-MSCs with redifferentiation in clinical applications.

Comparative study of adipose-derived stem cells and bone marrow-derived stem cells in similar microenvironmental conditions

Mesenchymal stem cells (MSCs), which were first isolated from the bone marrow, are now being extracted from various other tissues in the body, including the adipose tissue. The current study presents systematic evidence of how the adipose tissue-derived stem cells (ASCs) and bone marrow-derived mesenchymal stem cells (Bm-MSCs) behave when cultured in specific pro-adipogenic microenvironments. The cells were first characterized and identified as MSCs in terms of their morphology, phenotypic expression, self-renewal capabilities and multi-lineage potential. Subsequently, the proliferation and gene expression profiles of the cell populations cultured on two-dimensional (2D) adipose tissue extracellular matrix (ECM)-coated tissue culture plastic (TCP) and in three-dimensional (3D) AlgiMatrix® microenvironments were analyzed. Overall, it was found that adipogenesis was triggered in both cell populations due to the presence of adipose tissue ECM. However, in 3D microenvironments, ASCs and Bm-MSCs were predisposed to the adipogenic and osteogenic lineages respectively. Overall, findings from this study will contribute to ongoing efforts in adipose tissue engineering as well as provide new insights into the role of the ECM and cues provided by the immediate microenvironment for stem cell differentiation.

Multipotency of Adult Hippocampal NSCs In Vivo Is Restricted by Drosha/NFIB

Adult neural stem cells (NSCs) are defined by their inherent capacity to self-renew and give rise to neurons, astrocytes, and oligodendrocytes. Invivo, however, hippocampal NSCs do not generate oligodendrocytes for reasons that have remained enigmatic. Here, we report that deletion of Drosha in adult dentate gyrus NSCs activates oligodendrogenesis and reduces neurogenesis at the expense of gliogenesis. We further find that Drosha directly targets NFIB to repress its expression independently of Dicer and microRNAs. Knockdown of NFIB in Drosha-deficient hippocampal NSCs restores neurogenesis, suggesting that the Drosha/NFIB mechanism robustly prevents oligodendrocyte fate acquisition invivo. Taken together, our findings establish that adult hippocampal NSCs inherently possess multilineage potential but that Drosha functions as a molecular barrier preventing oligodendrogenesis.

Macromolecular crowding meets oxygen tension in human mesenchymal stem cell culture - A step closer to physiologically relevant in vitro organogenesis.

Modular tissue engineering is based on the cells’ innate ability to create bottom-up supramolecular assemblies with efficiency and efficacy still unmatched by man-made devices. Although the regenerative potential of such tissue substitutes has been documented in preclinical and clinical setting, the prolonged culture time required to develop an implantable device is associated with phenotypic drift and/or cell senescence. Herein, we demonstrate that macromolecular crowding significantly enhances extracellular matrix deposition in human bone marrow mesenchymal stem cell culture at both 20% and 2% oxygen tension. Although hypoxia inducible factor - 1α was activated at 2% oxygen tension, increased extracellular matrix synthesis was not observed. The expression of surface markers and transcription factors was not affected as a function of oxygen tension and macromolecular crowding. The multilineage potential was also maintained, albeit adipogenic differentiation was significantly reduced in low oxygen tension cultures, chondrogenic differentiation was significantly increased in macromolecularly crowded cultures and osteogenic differentiation was not affected as a function of oxygen tension and macromolecular crowding. Collectively, these data pave the way for the development of bottom-up tissue equivalents based on physiologically relevant developmental processes.

Generating human hematopoietic stem cells in vitro -exploring endothelial to hematopoietic transition as a portal for stemness acquisition.

Advances in cellular reprogramming technologies have created alternative platforms for the production of blood cells, either through inducing pluripotency in somatic cells or by way of direct conversion of nonhematopoietic cells into blood cells. However, de novo generation of hematopoietic stem cells (HSCs) with robust and sustained multilineage engraftment potential remains a significant challenge. Hemogenic endothelium (HE) has been recognized as a unique transitional stage of blood development from mesoderm at which HSCs arise in certain embryonic locations. The major aim of this review is to summarize historical perspectives and recent advances in the investigation of endothelial to hematopoietic transition (EHT) and HSC formation in the context of aiding in vitro approaches to instruct HSC fate from human pluripotent stem cells. In addition, direct conversion of somatic cells to blood and HSCs and progression of this conversion through HE stage are discussed. A thorough understanding of the intrinsic and microenvironmental regulators of EHT that lead to the acquisition of self-renewal potential by emerging blood cells is essential to advance the technologies for HSC production and expansion.

138 - Neurosphere Formation Enhances the Neurogenic Differentiation Potential and Migratory Ability of Umbilical Cord-Mesenchymal Stromal Cells

Background: The human umbilical cord (UC) is a rich source of mesenchymal stromal cells (MSCs), which have been reported to possess multi-lineage potential. The objectives of this study are to investigate the characteristics and capacity of UC-MSC neurosphere formation and whether this event enhances the propensity of UC-MSCs to undergo neural differentiation.

Long-Term Tracking Mesenchymal Stem Cell Differentiation with Photostable Fluorescent Nanoparticles.

Mesenchymal stem cells (MSCs) have proved to be a promising and abundant cell source for tissue and organ repair in regenerative medicine. However, the cell fate, distribution and migration of these transplanted cells are still unclear due to the limited tracking methods. It is desirable to develop a biocompatible and photostable probe to label the MSCs for long-term tracking without affecting the cell proliferation and potency. Herein we apply a recently developed nanoprobe system, in which di(thiophene-2-yl)-diketopyrrolopyrrole (DPP) is covalently linked in the middle of polycaprolactone (PCL) forming the PCL-DPP-PCL polymer complex. Although the PCL-DPP-PCL nanoparticles uptaken by the MSCs did not affect the cell viability, it was interesting that they exhibited different effects on the multilineage potency of the MSCs in the subsequent differentiation in vitro. Specifically, we found that the PCL-DPP-PCL labeling was unfavorable to the MSC osteogenic differentiation, whereas the labeled MSCs exhibited the same adipogenic and chondrogenic differentiations compared to the unlabeled controls as verified by gene expressions and histological staining. Furthermore, the PCL-DPP-PCL nanoparticles remained strong fluorescence intensity even after 4 weeks of differentiation. This study indicated that PCL-DPP-PCL nanoparticles could be used for long-term cell tracing in MSC differentiation into adipogenic and chondrogenic lineages.

Comparison of TGF-β1 and NO production by mesenchymal stem cells isolated from murine lung and adipose tissues

Context: Mesenchymal stem cells (MSCs) are cell sources for tissues regeneration. By secretion of soluble factors including transforming growth factor-β (TGF-β1) and nitric oxide (NO), MSCs are also able to regulate the immune system. MSCs have been disclosed in lung and adipose tissues with insufficient comparison between the tissues.Objectives: In this study, specific differentiation and the expression of surface antigens as well as TGF-β1 and NO productive levels were compared in murine lung-derived MSCs (LMSCs) and adipose tissue-derived MSCs (ADMSCs).Materials and methods: MSCs were isolated from murine lung and adipose tissues and cultured. Both cell populations were characterized using multilineage potential and the expression of surface antigenic proteins, CD73, CD105, CD34, CD45, and CD11b. Finally, levels of TGF-β1 and NO were evaluated and compared in ADMSCs and LMSCs.Results: Expression of CD73 and CD105; lack of the expression of CD34, CD45, and CD11b markers; as well as adipocyte and osteocyte differentiations were detected in both adult stem cells. No significant difference was found in TGF-β1 and NO production between two stem cell populations.Conclusion: Our data showed that LMSCs and ADMSCs have comparable phenotype and TGF-β1 and NO production.

Abstract B24: Differentiation screen identifies small molecules that target histologically divergent subtypes of patient-derived lung cancer stem cells

Abstract Non-small cell lung cancer (NSCLC) is a prevalent and deadly disease because of high incidence and relapse rates. One hypothesis for the high relapse rate is the existence of cancer stem cells (CSCs), a rare subpopulation of cells within these tumors, that are resistant to therapy and thought to be responsible for local and distal recurrence. CSCs are also able to self-renew and differentiate into multiple cell types forming the mass of new tumors. These differentiated progeny that constitute the bulk of the tumor are more sensitive to radiation and chemotherapeutic agents, express tissue of origin markers, and have an intrinsically limited lifespan. While most solid tumors have these properties, the degree of heterogeneity from patient to patient in the multi-lineage potential of the CSC population is not known. In particular, NSCLC CSC populations from primary patient tumors have not been well studied. The goal of this study was to characterize newly derived NSCLC CSC lines to determine the degree of heterogeneity between patient samples, and to provide a starting point for the discovery of novel differentiation therapeutic agents to target CSCs. We isolated six CSC lines from primary patient NSCLC tumors using an unbiased culture-based enrichment method, rather than a biased marker-based approach. Each of these six CSC lines was tumorigenic in immunodeficient mice at low cell numbers and the resulting tumors recapitulated the original tumor histology. All-trans retinoic acid (ATRA), a well-known differentiation agent for the treatment of acute promyelocytic leukemia (APL), maintains the normal growth and differentiation of human bronchial epithelial cells in culture. Each of the six CSC lines was treated with ATRA for two weeks to induce differentiation and then assessed for transcript and protein levels of candidate CSC and differentiation markers. Pre-treatment, the CSC lines all expressed CD44. Post-ATRA treatment, the majority of the CSC lines expressed Mucin-2, a marker of Goblet cell lineage. In addition, each cell line started to show evidence of the very early stages of differentiation into other lineages including Clara Cells, Neuroendocrine Cells, and Alveolar Type I and Type II cells. In one CSC line, ATRA treatment both in vitro and in vivo delayed tumor cell growth, induced the expression of Mucin-2 and decreased the expression of Nestin, a cancer stem cell marker. To further characterize CSC differentiation potential, we screened a pilot set of small molecules in two independent CSC lines to identify compounds that induce terminal differentiation, using Mucin-2 expression as readout. Surprisingly, despite the fact that these two CSC lines were from different histological subtypes (adenocarcinoma and squamous cell carcinoma) and displayed different transcriptional profiles post-differentiation, there was a good correlation between hit sets in the screens. Taken together, these data suggest that while the CSC of origin in tumors differs between patient samples in profile and function, there is promise to identify differentiation agents that are broadly active in different NSCLC subtypes. Further screening is currently being performed to identify these novel differentiation agents for therapeutic use. Citation Format: Dina Shlyakhter, Diane Boucher, Yong Gu, Amy B. Hall, Elaine Krueger, Anna Lindquist, Cheryl Murphy, Yuxin Wang, Mark Wood, Brenda Eustace. Differentiation screen identifies small molecules that target histologically divergent subtypes of patient-derived lung cancer stem cells. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr B24.

Long term morphological characterization of mesenchymal stromal cells 3D spheroids built with a rapid method based on entry-level equipment.

Three-dimensional (3D) spheroids of mesenchymal stromal cells (MSC) have been demonstrated to improve a wide range of MSC features, such as multilineage potential, secretion of therapeutic factors, and resistance against hypoxic condition. Accordingly, they represent a promising tool in regenerative medicine for several biological and clinical applications. Many approaches have been proposed to generate MSC spheroids. They usually require specific generation systems, such as rotatory bioreactors or low-attachment plates, and each approach has its own disadvantages. Furthermore, an over-time analysis of morphological homogeneity and architectural stability of the spheroids generated is rarely provided. In this work we adapted the "pellet culture" method to obtain homogenous spheroids of MSC and maintain them in vitro for long term studies. We analysed their outer and inner structure over a 2-month period to provide morphological and architectural information regarding the spheroids generated. Quantitative and qualitative data were obtained using brightfield and confocal microscope imaging coupled to a computational analysis to estimate volume, sphericity, and jagging degree. In addition, histological evaluation was performed to more thoroughly assess the cellular composition and the internal architecture of the 3D spheroids. The results provided show that MSC spheroids generated with the proposed approach are homogeneous and stable, from both morphological and architectural points of view, for a period of at least 15days, approximately between day 15 and day 30 after their generation. Accordingly, the approach proposed serves as a rapid, cost-effective, and efficient method to generate and maintain MSC spheroids using common entry-level laboratory equipment only.

Adipogenic placenta-derived mesenchymal stem cells are not lineage restricted by withdrawing extrinsic factors: developing a novel visual angle in stem cell biology.

Current evidence implies that differentiated bone marrow mesenchymal stem cells (BMMSCs) can act as progenitor cells and transdifferentiate across lineage boundaries. However, whether this unrestricted lineage has specificities depending on the stem cell type is unknown. Placental-derived mesenchymal stem cells (PDMSCs), an easily accessible and less invasive source, are extremely useful materials in current stem cell therapies. No studies have comprehensively analyzed the transition in morphology, surface antigens, metabolism and multilineage potency of differentiated PDMSCs after their dedifferentiation. In this study, we showed that after withdrawing extrinsic factors, adipogenic PDMSCs reverted to a primitive cell population and retained stem cell characteristics. The mitochondrial network during differentiation and dedifferentiation may serve as a marker of absent or acquired pluripotency in various stem cell models. The new population proliferated faster than unmanipulated PDMSCs and could be differentiated into adipocytes, osteocytes and hepatocytes. The cell adhesion molecules (CAMs) signaling pathway and extracellular matrix (ECM) components modulate cell behavior and enable the cells to proliferate or differentiate during the differentiation, dedifferentiation and redifferentiation processes in our study. These observations indicate that the dedifferentiated PDMSCs are distinguishable from the original PDMSCs and may serve as a novel source in stem cell biology and cell-based therapeutic strategies. Furthermore, whether PDMSCs differentiated into other lineages can be dedifferentiated to a primitive cell population needs to be investigated.

Cancer Stem Cells in the Thyroid.

The cancer stem cell (CSC) model posits that CSCs are a small, biologically distinct subpopulation of cancer cells in each tumor that have self-renewal and multi-lineage potential, and are critical for cancer initiation, metastasis, recurrence, and therapy-resistance. Numerous studies have linked CSCs to thyroid biology, but the candidate markers and signal transduction pathways that drive thyroid CSC growth are controversial, the origin(s) of thyroid CSCs remain elusive, and it is unclear whether thyroid CSC biology is consistent with the original hierarchical CSC model or the more recent dynamic CSC model. Here, we critically review the thyroid CSC literature with an emphasis on research that confirmed the presence of thyroid CSCs by in vitro sphere formation or in vivo tumor formation assays with dispersed cells from thyroid cancer tissues or bona fide thyroid cancer cell lines. Future perspectives of thyroid CSC research are also discussed.

Characterisation of stresses on microcarriers in a stirred bioreactor

A computational fluid dynamics model for the flow of culture in a Corning™ spinner-flask stirred bioreactor has been used to characterise stresses experienced by microcarriers immersed in the fluid. Validation of the turbulent flow using experimental Particle Image Velocimetry (PIV) found advanced Large Eddy Simulation (LES) to be superior to Unsteady Reynolds averaging (URANS) modelling as a computational strategy for accurately capturing instantaneous velocity fluctuations of the types observed in the experiments. The simulations demonstrated that stress exposures experienced by microcarriers were highest during impeller start-up. After start-up, microcarriers experienced elevated levels of fluctuating stress of magnitudes known to cause cell differentiation, potentially compromising expansion of a homogeneous population with multi-lineage potential. Decreasing the impeller speed from 70 RPM to 50 RPM in the Corning™ flask was not found to necessarily reduce microcarrier stress exposure, because such a measure does not control the spatio-temporal coincidence of the microcarrier population with high regions of stress within the bioreactor. Modifications to bioreactor geometries and operational protocols are identified that can be pursued if such issues with dynamic stem cell culture arise.

Mesenchymal stromal cells from the foreskin: Tissue isolation, cell characterization and immunobiological properties

Background aimsBecause of their self-renewal capacity, multilineage potential and immunomodulatory properties, MSCs are an attractive tool for cell-based immunotherapy strategies. Foreskin, considered as a biological waste material, has been shown to be a reservoir of therapeutic cells. MethodsMSCs were isolated from different foreskin samples, maintained under in vitro culture and defined according to the International Society for Cellular Therapy (ISCT) criteria. We subsequently determined their main cell characteristics as well as their immunobiological properties. The following parameters were determined: (i) morphology and phenotype, (ii) proliferative and clonogenic potentials, (iii) tri-lineage differentiation ability, (iv) immunological profile, (v) immunomodulatory properties and (vi) protein and messenger RNA expression/secretion profile of immunoregulatory cytokines/factors as well as the pattern of toll-like receptors (TLRs). By using a pro-inflammatory cytokine cocktail, we also evaluated the influence of an inflammatory environment on their biology. ResultsWith a typical fibroblast-like morphology and an ISCT-compliant phenotype, foreskin-MSCs (FSK-MSCs) were highly proliferative and had a great clonogenic potential. They displayed multilineage capacities and interesting immunomodulatory properties. Of importance, FSK-MSCs were not immunogenetic and were further able to inhibit T-cell proliferation. We showed that several immunoregulatory cytokines and factors might be potentially involved in FSK-MSC immunomodulation with particular attention to hepatocyte growth factor and interleukin-11. Moreover, FSK-MSCs expressed several TLRs and were sensitive to the inflammatory environment by properly adjusting their profile and fate. ConclusionsForeskin represents a new alternative source for MSCs that is compliant with ISCT criteria. Their unique immunobiological properties allow consideration of FSK-MSCs as a valuable tolerogenic product for cell-based immunotherapy.

Mesenchymal Stem Cells and Mononuclear Cells From Cord Blood: Cotransplantation Provides a Better Effect in Treating Myocardial Infarction.

The aim of this study was to evaluate the effect of cotransplanting mononuclear cells from cord blood (CB-MNCs) and mesenchymal stem cells (MSCs) as treatment for myocardial infarction (MI). Transplanting CD34+ cells or MSCs separately has been shown effective in treating MI, but the effect of cotransplanting CB-MNCs and MSCs is not clear. In this study, MSCs were separated by their adherence to the tissue culture. The morphology, immunophenotype, and multilineage potential of MSCs were analyzed. CB-MNCs were separated in lymphocyte separation medium 1.077. CD34+ cell count and viability were analyzed by flow cytometry. Infarcted male Sprague-Dawley rats in a specific-pathogen-free grade were divided into four treatment groups randomly: group I, saline; group II, CB-MNCs; group III, MSCs; and group IV, CB-MNCs plus MSCs. The saline, and CB-MNCs and/or MSCs were injected intramyocardially in infarcted rats. Their cardiac function was evaluated by echocardiography. The myocardial capillary density was analyzed by immunohistochemistry. Both cell types induced an improvement in the left ventricular cardiac function and increased tissue cell proliferation in myocardial tissue and neoangiogenesis. However, CB-MNCs plus MSCs were more effective in reducing the infarct size and preventing ventricular remodeling. Scar tissue was reduced significantly in the CB-MNCs plus MSCs group. MSCs facilitate engraftment of CD34+ cells and immunomodulation after allogeneic CD34+ cell transplantation. Cotransplanting MSCs and CB-MNCs might be more effective than transplanting MSCs or CB-MNCs separately for treating MI. This study contributes knowledge toward effective treatment strategies for MI.

Magnetic induction heating of superparamagnetic nanoparticles during rewarming augments the recovery of hUCM-MSCs cryopreserved by vitrification

Cryopreservation by vitrification has been recognized as a promising strategy for long-term banking of living cells. However, the difficulty to generate a fast enough heating rate to minimize devitrification and recrystallization-induced intracellular ice formation during rewarming is one of the major obstacles to successful vitrification. We propose to overcome this hurdle by utilizing magnetic induction heating (MIH) of magnetic nanoparticles to enhance rewarming. In this study, superparamagnetic (SPM) Fe3O4 nanoparticles were synthesized by a chemical coprecipitation method. We successfully applied the MIH of Fe3O4 nanoparticles for rewarming human umbilical cord matrix mesenchymal stem cells (hUCM-MSCs) cryopreserved by vitrification. Our results show that extracellular Fe3O4 nanoparticles with MIH may efficiently suppress devitrification and/or recrystallization during rewarming and significantly improve the survival of vitrified cells. We further optimized the concentration of Fe3O4 nanoparticles and the current of an alternating current (AC) magnetic field for generating the MIH to maximize cell viability. Our results indicate that MIH in an AC magnetic field with 0.05% (w/v) Fe3O4 nanoparticles significantly facilitates rewarming and improves the cryopreservation outcome of hUCM-MSCs by vitrification. The application of MIH of SPM nanoparticles to achieve rapid and spatially homogeneous heating is a promising strategy for enhanced cryopreservation of stem cells by vitrification. Statement of SignificanceHere we report the successful synthesis and application of Fe3O4 nanoparticles for magnetic induction heating (MIH) to enhance rewarming of vitrification-cryopreserved human umbilical cord matrix mesenchymal stem cells (hUCM-MSCs). We found that MIH-enhanced rewarming greatly improves the survival of vitrification-cryopreserved hUCM-MSCs. Moreover, the hUCM-MSCs retain their intact stemness and multilineage potential of differentiation post cryopreservation by vitrification with the MIH-enhanced rewarming. Therefore, the novel MIH-enhanced cell vitrification is valuable to facilitate the long-term storage of hUCM-MSCs and possibly many other important cells to meet their ever-increasing demand by the burgeoning cell-based medicine.

Neurosphere formation enhances the neurogenic differentiation potential and migratory ability of umbilical cord-mesenchymal stromal cells

Background aimsThe human umbilical cord (UC) is a rich source of mesenchymal stromal cells (MSCs), which have been reported to have multi-lineage potential. The objectives of this study were to investigate the characteristics and capacity of UC-MSC neurosphere formation and whether this event enhances the propensity of UC-MSCs to undergo neural differentiation. MethodsUC-MSCs were collected by the improved explant method. UC-MSCs and neurosphere-forming UC-MSCs (UC-MSC-neurospheres) were induced to undergo neurogenic differentiation, the latter of which were induced by suspension culturing in the presence of epidermal growth factor and basic fibroblast growth factor. The differentiation and migratory capacities of the individual cultures were then compared on the basis of the expression of neural markers, as measured by immunocytochemistry, immunoblotting and quantitative real-time polymerase chain reaction and transwell assays, respectively. ResultsBoth UC-MSCs and UC-MSC-neurospheres were capable of differentiating into neurogenic cells when cultured in neurogenic differentiation medium. However, pre-conditioned UC-MSC-neurospheres exhibited significantly higher expression of neural markers—including microtubule-associated protein (MAP2), MUSASHI1, glial fibrillary acidic protein (GFAP), and NESTIN—compared with those derived from UC-MSCs directly. Moreover, UC-MSC-neurospheres expressed significantly higher levels of the stemness markers NANOG, KLF4 and OCT4 than did UC-MSCs. Migration assays also revealed that both UC-MSCs and UC-MSC-neurospheres actively migrate toward glucose-depleted cells. ConclusionsNeurogenic differentiation potential probably is greater in UC-MSC-neurospheres than in UC-MSCs. Thus, UC-MSC-neurospheres may serve as a better source of cells for neurogenic regenerative medicine.