ABSTRACT
Despite the development of various in vitro differentiation protocols for the efficient derivation of specific cell types, human induced pluripotent stem cell (hiPSC) lines have varing ability to differentiate into specific lineages. Therefore, surrogate markers for accurately predicting the differentiation propensity of hiPSC lines may facilitate cell-based therapeutic product development and manufacture. We attempted to identify marker genes that could predict the differentiation propensity of hiPSCs into neural stem/progenitor cells (NS/PCs). Using Spearman's rank correlation coefficients, we investigated genes in the undifferentiated state, the expression levels of which were significantly correlated with the neuronal differentiation propensity of several hiPSC lines. Among genes significantly correlated with NS/PC differentiation (P < 0.01), we identified ROR2 as a novel predictive marker. ROR2 expression in hiPSCs was negatively correlated with NS/PC differentiation tendency, regardless of the differentiation method, whereas its knockdown enhanced differentiation. ROR2 regulates NS/PC differentiation, suggesting that ROR2 is functionally essential for NS/PC differentiation. Selecting cell lines with relatively low ROR2 expression facilitated identification of hiPSCs that can differentiate into NS/PCs. Cells with ROR2 knockdown showed increased efficiency of differentiation into forebrain GABAergic neurons compared to controls. These findings suggest that ROR2 is a surrogate marker for selecting hiPSC lines appropriate for NS/PC and GABAergic neuronal differentiations.
Subject(s)
Induced Pluripotent Stem Cells , Humans , Cell Differentiation/genetics , Cell Line , Commerce , GABAergic Neurons , Receptor Tyrosine Kinase-like Orphan Receptors/geneticsABSTRACT
Human multipotent mesenchymal stromal/stem cells (MSCs) have been utilized in cell therapy for various diseases and their clinical applications are expected to increase in the future. However, the variation in MSC-based product quality due to the MSC heterogeneity has resulted in significant constraints in the clinical utility of MSCs. Therefore, we hypothesized that it might be important to identify and ensure/enrich suitable cell subpopulations for therapies using MSC-based products. In this study, we aimed to identify functional cell subpopulations to predict the efficacy of angiogenic therapy using bone marrow-derived MSCs (BM-MSCs). To assess its angiogenic potency, we observed various levels of vascular endothelial growth factor (VEGF) secretion among 11 donor-derived BM-MSC lines under in vitro ischemic culture conditions. Next, by clarifying the heterogeneity of BM-MSCs using single-cell RNA-sequencing analysis, we identified a functional cell subpopulation that contributed to the overall VEGF production in BM-MSC lines under ischemic conditions. We also found that leucine-rich repeat-containing 75A (LRRC75A) was more highly expressed in this cell subpopulation than in the others. Importantly, knockdown of LRRC75A using small interfering RNA resulted in significant inhibition of VEGF secretion in ischemic BM-MSCs, indicating that LRRC75A regulates VEGF secretion under ischemic conditions. Therefore, LRRC75A may be a useful biomarker to identify cell subpopulations that contribute to the angiogenic effects of BM-MSCs. Our work provides evidence that a strategy based on single-cell transcriptome profiles is effective for identifying functional cell subpopulations in heterogeneous MSC-based products.
Subject(s)
Mesenchymal Stem Cells , Vascular Endothelial Growth Factor A , Humans , Bone Marrow Cells , Cell Differentiation , Cell Proliferation , Ischemia/genetics , Ischemia/therapy , Ischemia/metabolism , Single-Cell Gene Expression Analysis , Stem Cells , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factors/metabolism , Vascular Endothelial Growth Factors/pharmacologyABSTRACT
Introduction: Contamination of human cell-processed therapeutic products (hCTPs) with tumorigenic/immortalized cellular impurities is a major concern in the manufacturing and quality control of hCTPs. The cellular immortality test based on cell growth analysis is a method for detecting tumorigenic/immortalized cellular impurities in hCTPs. However, the performance of the cellular immortality test has not yet been well characterized. In this study, we examined the reproducibility of the cellular immortality test in detecting HeLa cells as a model of tumorigenic cellular impurities, as well as the applicability of other models of cellular impurities with different tumorigenicity to the cellular immortality test. Methods: Using HeLa cells as a model for cellular impurities, we measured the growth rate of human mesenchymal stem cells (hMSCs) supplemented with HeLa cells at concentrations ranging from 0.01 to 0.0001% at each passage in three laboratories and evaluated the reproducibility of the detection of immortalized cellular impurities. In addition, HEK293 cells (another immortalized cell line) and MRC-5 cells (a non-immortalized cell line) were employed as cellular impurity models that exhibit different growth characteristics from HeLa cells, and the ability of the cellular immortality test to detect these different impurities when mixed with hMSCs was examined. Results: In the multisite study, the growth rate of hMSCs supplemented with 1 and 10 HeLa cells (0.0001% and 0.001%) significantly increased and reached a plateau in all three laboratories, whereas those of hMSCs alone eventually decreased. Moreover, when hMSCs were supplemented with 10 and 100 HEK293 and MRC-5 cells (0.001% and 0.01%), the growth rate significantly increased. The growth rate of hMSCs supplemented with HEK293 cells increased with passage and remained high, whereas that of hMSCs supplemented with MRC-5 cells eventually decreased, as in the case of hMSCs alone. Conclusions: These results indicate that the cellular immortality test is reproducible and can detect immortalized (i.e., potentially tumorigenic) cells such as HEK293 cells with a lower growth rate than HeLa cells by discriminating against normal cells, which could contribute to ensuring the safety and quality of hCTPs.
ABSTRACT
Highly sensitive detection of residual undifferentiated pluripotent stem cells is essential for the quality and safety of cell-processed therapeutic products derived from human induced pluripotent stem cells (hiPSCs). We previously reported the generation of an adenovirus (Ad) vector and adeno-associated virus vectors that possess a suicide gene, inducible Caspase 9 (iCasp9), which makes it possible to sensitively detect undifferentiated hiPSCs in cultures of hiPSC-derived cardiomyocytes. In this study, we investigated whether these vectors also allow for detection of undifferentiated hiPSCs in preparations of hiPSC-derived neural progenitor cells (hiPSC-NPCs), which have been expected to treat neurological disorders. To detect undifferentiated hiPSCs, the expression of pluripotent stem cell markers was determined by immunostaining and flow cytometry. Using immortalized NPCs as a model, the Ad vector was identified to be the most efficient among the vectors tested in detecting undifferentiated hiPSCs. Moreover, we found that the Ad vector killed most hiPSC-NPCs in an iCasp9-dependent manner, enabling flow cytometry to detect undifferentiated hiPSCs intermingled at a lower concentration (0.002%) than reported previously (0.1%). These data indicate that the Ad vector selectively eliminates hiPSC-NPCs, thus allowing for sensitive detection of hiPSCs. This cytotoxic viral vector could contribute to ensuring the quality and safety of hiPSCs-NPCs for therapeutic use.
Subject(s)
Induced Pluripotent Stem Cells/cytology , Myocytes, Cardiac/cytology , Neural Stem Cells/cytology , Adenoviridae/genetics , Cell Differentiation , Cells, Cultured , Genetic Vectors , HumansABSTRACT
Cell-processed therapeutic products (CTPs) derived from human pluripotent stem cells (hPSCs) have innovative applications in regenerative medicine. However, undifferentiated hPSCs possess tumorigenic potential; thus, sensitive methods for the detection of residual undifferentiated hPSCs are essential for the clinical use of hPSC-derived CTPs. The detection limit of the methods currently available is 1/105 (0.001%, undifferentiated hPSCs/differentiated cells) or more, which could be insufficient for the detection of residual hPSCs when CTPs contain more than 1 × 105 cells. In this study, we developed a novel approach to overcome this challenge, using adenovirus and adeno-associated virus (AdV and AAV)-based selective cytotoxic vectors. We constructed AdV and AAV vectors that possess a suicide gene, iCaspase 9 (iCasp9), regulated by the CMV promoter, which is dormant in hPSCs, for the selective expression of iCasp9 in differentiated cells. As expected, AdV/CMV-iCasp9 and AAV/CMV-iCasp9 exhibited cytotoxicity in cardiomyocytes but not in human induced pluripotent stem cells (hiPSCs). The vectors also induced apoptosis in hiPSC-derived cardiomyocytes, and the surviving cells exhibited higher levels of hPSC marker expression. These results indicate that the AdV- and AAV-based cytotoxic vectors concentrate cells expressing the undifferentiated cell markers in hiPSC-derived products and are promising biological tools for verifying the quality of CTPs.
Subject(s)
Adenoviridae/genetics , Cell Differentiation , Dependovirus/genetics , Genetic Vectors/administration & dosage , Induced Pluripotent Stem Cells/cytology , Myocytes, Cardiac/pathology , Regenerative Medicine , Adenoviridae Infections/virology , Genetic Vectors/genetics , Humans , Induced Pluripotent Stem Cells/metabolism , Induced Pluripotent Stem Cells/virology , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/virology , Parvoviridae Infections/virologyABSTRACT
Functionalizing biomaterials with peptides or polymers that enhance recruitment of endothelial cells (ECs) can reduce blood coagulation and thrombosis. To assess endothelialization of materials in vitro, primary ECs are generally used, although the characteristics of these cells vary among the donors and change with time in culture. Recently, primary cell lines immortalized by transduction of simian vacuolating virus 40 large T antigen or human telomerase reverse transcriptase have been developed. To determine whether immortalized ECs can substitute for primary ECs in material testing, we investigated endothelialization on biocompatible polymers using three lots of primary human umbilical vein endothelial cells (HUVEC) and immortalized microvascular ECs, TIME-GFP. Attachment to and growth on polymer surfaces were comparable between cell types, but results were more consistent with TIME-GFP. Our findings indicate that TIME-GFP is more suitable for in vitro endothelialization testing of biomaterials.
Subject(s)
Biocompatible Materials , Endothelial Cells/metabolism , Endothelium, Vascular/metabolism , Materials Testing , Biocompatible Materials/chemistry , Cell Adhesion , Cell Line, Transformed , Human Umbilical Vein Endothelial Cells , Humans , Peptides , Polymers , Surface PropertiesABSTRACT
In human cell-processed therapeutic products (hCTPs) for clinical application, tumorigenic cellular impurities in the manufacturing process are a major concern. Because cellular immortalization is one of the prerequisite steps in tumorigenesis, we tested whether cell growth analysis can be employed to check for immortalized (and potentially tumorigenic) cellular impurities in hCTPs. We monitored the growth of human bone marrow-derived mesenchymal stem cells (BMSCs) mixed with HeLa cells at a ratio of 1/106 or more and compared their growth rates with that of BMSCs alone. The cell growth analysis detected a significant increase in the growth rate of the BMSCs spiked with 0.0001% HeLa within 30 days at a probability of 47%. When human adipose-derived stem cells (ADSCs) were spiked with ASC52telo cells, a human telomerase reverse transcriptase (hTERT)-immortalized adipose-derived mesenchymal stem cell line, at a ratio of 0.001% or more, their growth rates were significantly increased within 15 passages, compared with that of ADSCs alone. These results indicate that cell growth analysis for the detection of immortalized cellular impurities in human somatic stem cells is simple and can be useful for the quality assessment of hCTPs in the manufacturing process.
ABSTRACT
The contamination of human cell-processed therapeutic products (hCTPs) with tumorigenic cells is one of the major concerns in the manufacturing and quality control of hCTPs. However, no quantitative method for detecting the tumorigenic cellular impurities is currently standardized. NOD/Shi-scid IL2Rγnull (NOG) mice have shown high xeno-engraftment potential compared with other well-known immunodeficient strains, e.g. nude mice. Hypothesizing that tumorigenicity test using NOG mice could be a sensitive and quantitative method to detect a small amount of tumorigenic cells in hCTPs, we examined tumor formation after subcutaneous transplantation of HeLa cells, as a model of tumorigenic cells, in NOG mice and nude mice. Sixteen weeks after inoculation, the 50% tumor-producing dose (TPD50) values of HeLa cells were stable at 1.3 × 104 and 4.0 × 105 cells in NOG and nude mice, respectively, indicating a 30-fold higher sensitivity of NOG mice compared to that of nude mice. Transplanting HeLa cells embedded with Matrigel in NOG mice further decreased the TPD50 value to 7.9 × 10 cells, leading to a 5000-fold higher sensitivity, compared with that of nude mice. Additionally, when HeLa cells were mixed with 106 or 107 human mesenchymal stem cells as well as Matrigel, the TPD50 values in NOG mice were comparable to those of HeLa cells alone with Matrigel. These results suggest that the in vivo tumorigenicity test using NOG mice with Matrigel is a highly sensitive and quantitative method to detect a trace amount of tumorigenic cellular impurities in human somatic cells, which can be useful in the quality assessment of hCTPs.
ABSTRACT
The analysis of in vitro cell senescence/growth after serial passaging can be one of ways to show the absence of immortalized cells, which are frequently tumorigenic, in human cell-processed therapeutic products (hCTPs). However, the performance of the cell growth analysis for detection of the immortalized cellular impurities has never been evaluated. In the present study, we examined the growth rates of human mesenchymal stem cells (hMSCs, passage 5 (P = 5)) contaminated with various doses of HeLa cells, and compared with that of hMSCs alone. The growth rates of the contaminated hMSCs were comparable to that of hMSCs alone at P = 5, but significantly increased at P = 6 (0.1% and 0.01% HeLa) or P = 7 (0.001% HeLa) within 30 days. These findings suggest that the cell growth analysis is a simple and sensitive method to detect immortalized cellular impurities in hCTPs derived from human somatic cells.
Subject(s)
Cell Culture Techniques/methods , Mesenchymal Stem Cells/cytology , HeLa Cells , HumansABSTRACT
Precise quantification of cellular potential of stem cells, such as human bone marrow-derived mesenchymal stem cells (hBMSCs), is important for achieving stable and effective outcomes in clinical stem cell therapy. Here, we report a method for image-based prediction of the multiple differentiation potentials of hBMSCs. This method has four major advantages: (1) the cells used for potential prediction are fully intact, and therefore directly usable for clinical applications; (2) predictions of potentials are generated before differentiation cultures are initiated; (3) prediction of multiple potentials can be provided simultaneously for each sample; and (4) predictions of potentials yield quantitative values that correlate strongly with the experimental data. Our results show that the collapse of hBMSC differentiation potentials, triggered by in vitro expansion, can be quantitatively predicted far in advance by predicting multiple potentials, multi-lineage differentiation potentials (osteogenic, adipogenic, and chondrogenic) and population doubling potential using morphological features apparent during the first 4 days of expansion culture. In order to understand how such morphological features can be effective for advance predictions, we measured gene-expression profiles of the same early undifferentiated cells. Both senescence-related genes (p16 and p21) and cytoskeleton-related genes (PTK2, CD146, and CD49) already correlated to the decrease of potentials at this stage. To objectively compare the performance of morphology and gene expression for such early prediction, we tested a range of models using various combinations of features. Such comparison of predictive performances revealed that morphological features performed better overall than gene-expression profiles, balancing the predictive accuracy with the effort required for model construction. This benchmark list of various prediction models not only identifies the best morphological feature conversion method for objective potential prediction, but should also allow clinicians to choose the most practical morphology-based prediction method for their own purposes.
Subject(s)
Cell Differentiation/physiology , Mesenchymal Stem Cell Transplantation/methods , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/physiology , Models, Biological , Gene Expression Profiling/methods , Humans , Regenerative Medicine/methodsABSTRACT
Regenerative medicine is regarded as innovative therapy for severe diseases and damages caused by tissue loss and functional impairment. In Japan, regenerative medicine is one of the most important subjects issued by Council for Science and Technology Policy and also referred to in Medical Innovation of New Growth Strategy. Cell/tissue-processed products are living cells, which have been manipulated or processed for the purpose of regenerative medicine, and are extensively developing. Human somatic cells, somatic stem cells, embryonic stem cells, and induced pluripotent stem cells are cell sources used for regenerative medicine. Since we lack in experiences with cell/tissue-processed products, technical development of safety and quality assessment is urgently needed. National Institute of Health Sciences has carried out a mission of Regulatory Science and worked on safety assessment of pharmaceuticals and medical devices and their guideline development. The objective of our study is to develop safety and quality assessment methods for cell/tissue-processed products derived from stem cells, based on recent progresses in life science. We are currently developing methods to evaluate products as follows; a) useful and quantitative tumorigenicity tests to detect contamination of undifferentiated and/or abnormal cells in products, b) quality assessment by gene expression analysis and detection of genetic stability in a manufacturing process, and c) analysis of quality attributes associated with propensity of undifferentiated cells to set acceptable criteria of cell banks. We will be able to provide indicators to control the quality, efficacy and safety of stem cell-processed products and support efficient and economical promotion of the products. Especially, this study would help translate stem cell science into therapeutic products to patients with severe and life-threatening diseases, consequently contributing to administrative policy of Ministry of Health, Labor and Welfare.
Subject(s)
Biological Products , Cell- and Tissue-Based Therapy , Regenerative Medicine , Animals , Cell- and Tissue-Based Therapy/methods , Cell- and Tissue-Based Therapy/trends , Humans , Mice , Pluripotent Stem Cells , Quality Control , Regenerative Medicine/methods , Regenerative Medicine/trendsABSTRACT
Resveratrol (RSV), 3,5,4'-trihydroxy-trans-stilbene, is known to have many beneficial physiological activities. We have synthesized several stilbene analogues and have reported that the hydroxyl group in the 4' position of RSV exhibited strong radical scavenging action. Using stilbene analogs, we investigated the structure of RSV to explain its protective effect against obesity and type 2 diabetes. All six analogs used in this study inhibited the differentiation of 3T3-L1 adipocytes. 3-Hydroxy-trans stilbene (3(OH)ST), and 3,4'-dihydroxy-trans stilbene (3,4'(OH)2ST) increased glucose uptake and induced adenosine monophosphate kinase (AMPK) phosphorylation in C2C12 myotubes independently of insulin. An in vivo study using mice fed high-fat diets indicated that 3(OH)ST was more effective than RSV in improving insulin resistance. In conclusion, RSV and its derivatives, particularly 3(OH)ST, inhibited adipocyte differentiation and enhanced glucose uptake in the myotubes, resulting in a reduction of obesity and an improvement in glucose tolerance in vivo.
Subject(s)
AMP-Activated Protein Kinases/metabolism , Diabetes Mellitus, Type 2/drug therapy , Obesity/drug therapy , Stilbenes/administration & dosage , 3T3-L1 Cells , AMP-Activated Protein Kinases/genetics , Adipocytes/drug effects , Animals , Diabetes Mellitus, Type 2/pathology , Disease Models, Animal , Glucose/metabolism , Humans , Insulin/metabolism , Insulin Resistance/genetics , Mice , Obesity/pathology , Resveratrol , Stilbenes/chemical synthesisABSTRACT
In this study, a titanium surface was chemically modified with calcium ions and assessed for its influence on osteogenic differentiation and molecular responses of human mesenchymal stem cells (hMSCs). Titanium disks were treated with NaOH (NaOH treatment), NaOH + CaCl2 (CaCl2 treatment), or NaOH + Ca(OH)2 (Ca(OH)2 treatment). Ca(OH)2 treatment caused significantly greater calcium incorporation onto the titanium surface and apatite formation than CaCl2 treatment. The morphology of hMSCs differed on CaCl2- and Ca(OH)2-treated disks. The osteopontin (OPN) expression in hMSCs cultured on CaCl2-treated titanium was significantly higher than that in cells cultured on NaOH-treated disks; OPN expression was significantly higher in cells cultured on Ca(OH)2-treated disks than on un-, NaOH-, and CaCl2-treated disks. Osteocalcin (OCN) protein expression in hMSCs cultured on Ca(OH)2-treated disks was significantly higher than that on all the other disks. Comparative expression profiling by DNA microarray and pathway analyses revealed that calcium modification of the titanium surface induced integrin ß3 after OPN upregulation and promoted Wnt/ß-catenin signaling in hMSCs. In addition, Ca(OH)2 treatment upregulated the expression of bone morphogenetic protein 2, cyclooxygenase 2, and parathyroid hormone-like hormone in comparison to CaCl2 treatment. These observations suggest that calcium-modified titanium surfaces affect osteogenic differentiation in hMSCs and that Ca(OH)2 treatment induced osteogenic differentiation in hMSCs, whereas CaCl2 treatment had a limited effect.
Subject(s)
Calcium/chemistry , Coated Materials, Biocompatible/chemistry , Mesenchymal Stem Cells/cytology , Osteogenesis/physiology , Titanium/chemistry , Apatites/chemistry , Cell Differentiation , Cell Proliferation , Cells, Cultured , Humans , Materials Testing , Mesenchymal Stem Cells/metabolism , Oligonucleotide Array Sequence Analysis , Osteogenesis/genetics , Osteopontin/metabolism , Prostheses and Implants , Wnt Signaling PathwayABSTRACT
We examined the effects of serum-free medium on the gene expression changes in human mesenchymal stem cells (hMSCs) during the in vitro culture using a DNA microarray analysis. In this study, we cultured hMSCs with two kinds of medium; 1) MSCGM (contain 10% fetal bovine serum) or 2) STK2 (serum-free medium developed for mesechymal stem cells multiplication), and compared hMSCs proliferation, cell morphology, and gene expression changes until 50 days culture. Expression analysis was performed with Affymetrix GeneChip Human Genome U133 Plus 2.0 Array. hMSC proliferation was significantly higher in STK2 medium than in MSCGM medium. The cell morphology of hMSC cultured with STK2 was not significantly changed in 50 days culture. The gene expression changes in hMSCs during the in vitro culture were significantly higher in STK2 than in MSCGM. After 50 days culture, 1991 genes were significantly changed the expression levels compared with 3 days in STK2 but not MSCGM. The expressions of genes related to cell cycle, cancer, proliferation, and cell growth were significantly changed by STK2 for 50 days culture. It was also changed by STK2 that the expressions of genes related to the signaling pathways contain various growth factors, such as IGF-1, FGF, TGF-ß, EGF, proliferation, and cell cycle. These results suggest that STK2 may be useful to obtain an enough number of hMSC cells for tissue engineered medical devices in short-term, however, it should be recognized that STK2 would alter the expressions of genes related to a variety of signaling pathways in hMSC if the culture period would be extended to obtain a large number of cells.
Subject(s)
Culture Media, Serum-Free , Gene Expression/genetics , Mesenchymal Stem Cells , Oligonucleotide Array Sequence Analysis , Cell Proliferation , Cells, Cultured , Humans , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/physiology , Signal Transduction/genetics , Time FactorsABSTRACT
Fullerenes are condensed ring aromatic compounds with extended pi systems; they have unique cage structures. Current studies suggest that several fullerene derivatives have neuroprotective effects, and it is expected that fullerenes will be useful in drug delivery system and novel medical devices targeting the brain. However, little is known about the effects of fullerenes and its derivative on brain function. We examined the effect of fullerene(OH)24 on the central nervous system in this study. In a V79 colony assay, the IC50 of fullerene(OH)24 was 1.74 microg/ml. In an MTT assay, fullerene(OH)24 reduced proliferation of normal human astrocytes obviously. In an vivo study, 0.25 mg/kg(-1) of fullerene(OH)24 was injected into the lateral ventricle of rat brains. The intracerebral injection of fullerene(OH)24 remarkably decreased body weight and locomotor behavior of rats on day 1, but drastically increased locomotor behavior on day 7. The intracerebral injection of fullerene(OH)24 changed the monoamine concentration greatly on day 1 and slightly on day 30 after the injection. These results suggest that intracerebral injection of fullerene(OH)24 had strong and acute effects on the central nervous system, but that the effects were not permanent. In conclusion, we suggest that fullerene's derivative, fullerene(OH)24 had toxic effects on brain cells and that intracerebral injection of fullerene(OH)24 had acute harmful effects on brain monoamines neurotransmission and locomotor activity.
Subject(s)
Biogenic Monoamines/metabolism , Brain Chemistry/drug effects , Brain/drug effects , Fullerenes/pharmacology , Motor Activity/drug effects , Neurotransmitter Agents/metabolism , Analysis of Variance , Animals , Astrocytes/drug effects , Astrocytes/metabolism , Behavior, Animal/drug effects , Brain/cytology , Brain/metabolism , CHO Cells , Cell Survival/drug effects , Cells, Cultured , Cricetinae , Cricetulus , Dose-Response Relationship, Drug , Humans , Hydroxylation , Injections, Intraventricular , Male , Rats , Rats, Wistar , SolubilityABSTRACT
To apply human mesenchymal stem cells (hMSC) to regenerative medicines, it is necessary to multiply hMSC in vitro in a short period. In addition, it is desirable that the medium which is used for the hMSC multiplication is not supplemented with the serum, because the addition of the serum has risks of infection. In this study, we cultured hMSC with three kinds of medium used for multiplying hMSC (DMEM, MSCGM, STK2) and compared hMSC proliferation in each medium. As a result, it was confirmed that hMSC proliferation was significantly higher in STK2 medium which is a novel serum-free medium developed for hMSC multiplication. Moreover, we compared the hMSC proliferation in these media under the environment that assumed bone reproduction. When we cultured hMSC in each medium with hydroxyapatite (HAp), the proliferative inhibition by HAp depended on the additive amount, and the degree of the proliferative inhibition was different among the media but the lowest inhibitory effect was observed in STK2 medium.
Subject(s)
Cell Proliferation/drug effects , Culture Media, Serum-Free/pharmacology , Durapatite/pharmacology , Mesenchymal Stem Cells/cytology , Cells, Cultured , Depression, Chemical , Dose-Response Relationship, Drug , Humans , Stimulation, ChemicalABSTRACT
The purpose of tumorigenicity testing, as applied not only to cell substrates used for viral vaccine manufacture but also stem cells used for cell-based therapy, is to discriminate between cells that have the capacity to form tumors and cells that do not. Therefore, tumorigenicity testing is essential in assessing the safety of these biological materials. Recently developed NOD/Shi-scid IL2Rg(null) (NOG) mice have been shown to be superior to NOD/Shi-scid (SCID) mice for xenotransplantation of both normal and cancerous cells. To select a suitable mouse strain as a xenogenic host for tumorigenicity testing, we compared the susceptibility of NOG (T, B, and NK cell-defective), SCID (T and B cell-defective), and the traditionally used nude (T cell-defective) mice to tumor formation from xenotransplanted HeLa S3 cells. When 10(4) HeLa S3 cells were subcutaneously inoculated into the flanks of these mice, the tumor incidence on day 22 was 10/10 (100%) in NOG, 2/10 (20%) in SCID, and 0/10 (0%) in nude mice. The subcutaneous tumors formed reproducibly and semiquantitatively in a dose-dependent manner. Unexpectedly, half of the NOG mice (5/10) that had been inoculated with a mere 10(1) HeLa S3 cells formed progressively growing subcutaneous tumors on day 78. We confirmed that the engrafted tumors originated from inoculated HeLa S3 cells by immunohistochemical staining with anti-HLA antibodies. These data suggest that NOG mice may be the best choice as a suitable strain for testing tumorigenicity.
Subject(s)
Genetic Predisposition to Disease , Neoplasm Transplantation , Animals , Carcinogenicity Tests/methods , Female , HeLa Cells/transplantation , Humans , Male , Mice , Mice, Inbred NOD/genetics , Mice, Nude/genetics , Mice, SCID/genetics , Neoplasms, Experimental/pathology , Subcutaneous Tissue/pathology , Time Factors , Transplantation, HeterologousABSTRACT
Astrocyte proliferation is strictly controlled during development and in the adult nervous system. In this study, we examined the role of sulfated hyaluronan (SHya) in the proliferation and differentiation of normal human astrocytes (NHAs). Cells were cultured with different concentrations of SHya for 7 days, and the number of viable cells and the presence of neural cell-specific genes were determined to assess their proliferation and development, respectively. With SHya, cell proliferation increased nonsignificantly. Furthermore, remarkable enhancing action by SHya on connexin-26, -32, and -43 gene expressions were observed during the culture of NHAs. It has been suggested that a fraction of NHAs have neural precursor activity that gives rise to astrocytes themselves, oligodendrocytes, and neurons. Our results clearly demonstrated that the expression of specific genes for neural precursor cells, astrocytes, neurons, and oligodendrocytes was significantly increased to 50 mug/mL in SHya-treated cultures when compared with that of the control culture. These findings suggest that SHya plays an important role in the proliferation and differentiation of NHAs and in the production of a novel material for tissue engineering.
Subject(s)
Astrocytes/cytology , Connexins/genetics , Hyaluronic Acid/pharmacology , Cell Culture Techniques , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Cell Survival , Connexin 26 , Connexin 43/genetics , Gene Expression Regulation/drug effects , Humans , Tissue Engineering/methods , Gap Junction beta-1 ProteinABSTRACT
We investigated mRNA expression of c-myc and chromosome aberrations at the c-myc locus in the same passage number of human mesenchymal stem cells (hMSCs). To understand the sensitivity of mRNA expression and the induction of chromosome aberrations, we first tested them in hMSC and cancer cell lines (HeLa S3, HOS, and OUMS-27). The c-myc mRNA expressions in HeLa S3 and OUMS-27 were significantly higher than those in hMSC, but then those in HOS were not. On the other hand, c-myc aberrant cells detected by fluorescence in situ hybridization in HeLa S3, HOS, and OUMS-27 were significantly higher than that in hMSC. Both analyses were performed in hMSCs derived from five donors for the culture period of 50 days. In hMSCs from one donor, the frequency of c-myc aberrant cells significantly increased at 20 and 50 days respectively, and each mRNA expressions had a tendency to increase, but there is no significant change among 3, 20 and 50 days. In hMSCs from the others, both endpoints did not change for 50 days. For safe use of somatic stem cells in the regenerative medicine, the investigation of characteristic change of them during the in vitro culture is important. In the present study, we showed the mRNA expressions and chromosome aberrations of hMSCs in in vitro culture as the first step for establishing of safety evaluation of tissue engineered medical devices using normal hMSCs.