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1.
Technol Health Care ; 32(2): 1149-1158, 2024.
Article in English | MEDLINE | ID: mdl-38073345

ABSTRACT

BACKGROUND: To improve gait disability in patients with chronic stroke, ankle muscle strengthening and calf muscle stretching exercises are required. However, currently available ankle training equipment limit ankle exercises based on the position. Recently developed ankle training equipment enables spring resistance-based plantar press exercises to be performed in the standing position with weight support. OBJECTIVE: To conduct a usability test of the ankle training equipment in the standing position by stroke patients with hemiplegic gait and verify its effects on ankle movements. METHODS: The ankle training equipment was applied to five patients with chronic stroke and hemiplegic gait. In the standing position, the patients performed forefoot and rearfoot press exercises in the affected side with a day's interval at 20 repetitions maximum (RM). During the exercises, surface electromyography (sEMG) was used to measure the maximum voluntary isometric contraction (%MVIC) of the leg muscles. The System Usability Scale (SUS) was used to assess the ankle training equipment. Wilcoxon signed-rank test was used to evaluate the differences in muscle activity between the two exercises. RESULTS: Forefoot and rearfoot press exercises increased the %MVIC in the biceps femoris. Additionally, the tibialis anterior and medial gastrocnemius activity was significantly different between the two exercises. The SUS was 78.75% (SD 12.7). CONCLUSION: The usability test of the passive-control foot press trainer (PFPT) that with improvements in the structure and functions for convenience, it could be commercialized. PFPT could be an alternative to the ankle rehabilitation robot that necessitates a sitting position.


Subject(s)
Gait Disorders, Neurologic , Stroke , Humans , Ankle , Standing Position , Ankle Joint , Stroke/complications , Muscle, Skeletal/physiology , Electromyography , Gait/physiology
2.
Tissue Eng Part A ; 19(3-4): 329-39, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22891853

ABSTRACT

The human placenta, a complex organ, which facilitates exchange between the fetus and the mother, contains abundant extracellular matrix (ECM) components and well-preserved endogenous growth factors. In this study, we designed a new dermal substitute from human placentas for full-thickness wound healing. Highly porous, decellularized ECM sheets were fabricated from human placentas via homogenization, centrifugation, chemical and enzymatic treatments, molding, and freeze-drying. The physical structure and biological composition of human placenta-derived ECM sheets dramatically supported the regeneration of full-thickness wound in vivo. At the early stage, the ECM sheet efficiently absorbed wound exudates and tightly attached to the wound surface. Four weeks after implantation, the wound was completely closed, epidermic cells were well arranged and the bilayer structure of the epidermis and dermis was restored. Moreover, hair follicles and microvessels were newly formed in the ECM sheet-implanted wounds. Overall, the ECM sheet produced a dermal substitute with similar cellular organization to that of normal skin. These results suggest that human placenta-derived ECM sheets provide a microenvironment favorable to the growth and differentiation of cells, and positive modulate the healing of full-thickness wounds.


Subject(s)
Extracellular Matrix/chemistry , Intercellular Signaling Peptides and Proteins/pharmacology , Placenta/chemistry , Skin, Artificial , Skin/injuries , Skin/physiopathology , Wound Healing/physiology , Animals , Biological Dressings , Female , Humans , Intercellular Signaling Peptides and Proteins/chemistry , Materials Testing , Pregnancy , Rats , Rats, Sprague-Dawley , Tensile Strength , Treatment Outcome , Wounds, Penetrating/physiopathology , Wounds, Penetrating/therapy
3.
Cell Biochem Funct ; 30(3): 224-32, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22252741

ABSTRACT

JMJD3, a Jumonji C family histone demethylase, is induced by transcription factor, nuclear factor-kappa B (NF-κB), in response to various stimuli. JMJD3 is crucial for erasing histone-3 lysine-27 trimethylation (H3K27me3), a modification associated with transcriptional repression and is responsible for the activation of a diverse set of genes. Here, we identify the genes in human leukaemia monocyte (THP-1) human monocytic cells that are significantly affected by the stable knockdown (kd) of JMJD3. Global gene expression levels were detected in stable JMJD3 knockdown THP-1 cells and in tumor necrosis factor-alpha (TNF-α)-stimulated JMJD3-kd THP-1 cells by using a 12-plex NimbleGen human whole genome array. In addition, datasets were analysed by using Ingenuity Pathway Analysis. Stable knockdown of JMJD3 in THP-1 cells affected particularly in expression levels and in downstream effects on inflammatory signalling pathways. JMJD3 attenuation down-regulates various key genes in NF-κB, chemokine and CD40 signalling, and mostly affects inflammatory disease response molecules. In addition, chromatin immunoprecipitation revealed that JMJD3-kd could inhibit several NF-κB-regulated inflammatory genes by recruiting repressive histone-3 lysine-27 trimethylation to their promoters. Moreover, this study significantly highlights the connexion of NF-κB with JMJD3, which suggests an epigenetic regulation in different signalling pathways. Finally, this study establishes novel JMJD3 targets through Ingenuity Pathway Analysis.


Subject(s)
Gene Knockdown Techniques , Gene Regulatory Networks , Inflammation/genetics , Jumonji Domain-Containing Histone Demethylases/genetics , Monocytes/enzymology , Monocytes/immunology , Cell Line , Down-Regulation , Humans , Inflammation/immunology , Jumonji Domain-Containing Histone Demethylases/immunology , NF-kappa B/genetics , NF-kappa B/immunology , Signal Transduction
4.
J Microbiol Biotechnol ; 20(2): 438-45, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20208453

ABSTRACT

The immunomodulatory effects of exopolymers of Aureobasidium pullulans SM-2001 containing beta-1,3/1,6-glucan were evaluated on the cyclophosphamide (CPA)-treated mice. To induce immunosuppress, 150 and 110 mg/kg of CPA were intraperitoneally injected at 1 and 3 days before start of test material administrations, respectively. Exopolymers were subcutaneously or orally administered in a volume of 10 ml/kg, 4 times; 12-hr intervals from 24 hrs after second treatment of CPA. After treatment of exopolymers, the changes of thymus and spleen weights, splenic amounts of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-10, thymic and splenic CD3+, CD4+, CD8+ and TNF-alpha+ cells were monitored in CPA-treated mice. As results of CPA treatment, dramatical decreases of the CD3+, CD4+, CD8+ and TNF-alpha+ cells were detected in thymus and spleen with decreases of thymus and spleen weights. In addition, decreases of splenic TNF-alpha, IL-1beta and IL-10 contents were also detected at flow cytometrical observations. However, oral and subcutaneous treatment of exopolymers effectively reduced the immunosuppressive changes induced by CPA. Therefore, it is concluded that exopolymers of A. pullulans can be effectively prevent the immunosuppress mediated, at least partially, recruitment of T cells and TNF-alpha+ cells or enhancement of their activity, and can provide effective prevention or treat regimes for the immunosuppress and related diseases such as cancer, sepsis and high-dose chemotherapy or radiotherapy.


Subject(s)
Biopolymers/immunology , Cyclophosphamide/administration & dosage , Immunologic Factors/immunology , Polysaccharides/immunology , Saccharomycetales/immunology , Animals , Biopolymers/administration & dosage , Immunologic Factors/administration & dosage , Male , Mice , Mice, Inbred ICR , Polysaccharides/administration & dosage , Spleen/drug effects , Spleen/immunology , T-Lymphocytes , Thymus Gland/drug effects , Thymus Gland/immunology
5.
Neurosci Lett ; 468(3): 190-4, 2010 Jan 14.
Article in English | MEDLINE | ID: mdl-19879334

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by motor neuron loss. Although the underlying cause of the disease remains unclear, a variety of pathogenic mechanisms have been proposed. Despite promising preclinical studies showing the modification of the disease progression, most trials have failed to demonstrate any significant improvement in outcome. Stem cell therapy therefore has been proposed as an alternative therapy for ALS. In this study, we evaluated the dose-dependent effects of human bone marrow mesenchymal stem cells (hMSCs) obtained from an ALS patient (ALS-hMSCs) on SOD1 mice via intrathecal injection and showed its practicality for hMSCs. We transplanted different doses (1x10(4), 2x10(5), and 1x10(6)) of ALS-hMSCs into the cisterna magna and performed clinical observations including symptom onset, survival time, and locomotor performance using the rotarod test. Nissl staining was performed to evaluate motor neurons in lumbar spinal cord sections at 109 days, and transplanted cells were evaluated by immuno-fluorescence staining at the end stage. A cell dose of 1x10(6) cells significantly prolonged life span and delayed the decline of motor performance. At this dose, the average number of motor neurons was significantly higher than those of the untreated and 1x10(4) cell treated groups. Most injected hMSCs distributed in the ventricular system and subarachnoid space, while some migrated into the brain and spinal cord. These data suggest that intrathecal injection with an optimized cell number could be a potential route for stem cell therapy in ALS patients.


Subject(s)
Amyotrophic Lateral Sclerosis/therapy , Mesenchymal Stem Cell Transplantation , Superoxide Dismutase/genetics , Amyotrophic Lateral Sclerosis/pathology , Amyotrophic Lateral Sclerosis/physiopathology , Animals , Cisterna Magna , Humans , Injections, Spinal , Lumbosacral Region , Mice , Motor Activity , Motor Neurons/pathology , Spinal Cord/pathology
6.
J Nanosci Nanotechnol ; 8(9): 4579-83, 2008 Sep.
Article in English | MEDLINE | ID: mdl-19049062

ABSTRACT

Efficiency improvement and color optimization of white organic light-emitting diodes (WOLEDs) were achieved via employing blue host DPVBi doped with blue fluorescent, BCzVBi. The structure of high efficient WOLED device was composed of ITO/NPB/DPVBi:BCzVBi-6%/MADN:DCM2-0.5%/Bphen/Liq/Al. WOLED doped by blue fluorescent BCzVBi exhibits 6.19 cd/A of luminous efficiency and 15400 cd/m2 of maximum luminescence. It also performs 480 cd/m2 of luminance at 5.7 V and 15400 cd/m2 at 12.9 V with CIE(x,y) coordinates of (0.33, 0.32) and (0.32, 0.32), respectively. Hole carrier and energy transfer from DPVBi to BCzVBi are proposed to explain the observed phenomena.

7.
Differentiation ; 74(4): 149-59, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16683985

ABSTRACT

Cell replacement therapy is a promising approach for the treatment of cardiac diseases. It is, however, challenged by a limited supply of appropriate cells. Therefore, we have investigated whether functional cardiomyocytes can be efficiently generated from human embryonic stem cells (hESCs). In this study, we developed an efficient protocol for the generation of functional cardiomyocytes from hESCs by combining hanging drop culture and 5-azacytidine, a well-known demethylating agent, and then evaluated the expression of cardiac-specific markers. hESCs were cultured both in the medium without or with 0.1, 1, or 10 microM of 5-azacytidine under a hanging drop culture. The expression of several cardiac-specific markers was determined by real-time PCR, RT-PCR, immunofluorescence, and confocal microscopy. To verify the structural and functional properties of hESC-derived cardiomyocytes, we performed electron microscopy and electrophysiological recording. The efficiency of beating cell generation was significantly improved in the hanging drop culture compared with that in suspension culture. Treatment of hESCs with 0.1 microM of 5-azacytidine for 1-3 days significantly increased the number of beating cells and simultaneously enhanced the expression of cardiac-specific markers. Transmission electron microscopy and electrophysiological recording showed that hESC-derived cardiomyocytes acquired structural and functional properties of cardiomyocytes. In conclusion, these results suggest that differentiation of hESCs into cardiomyocytes can be enhanced by the combination of hanging drop culture and 5-azacytidine treatment. Also the methylation status of genes related to cardiomyocyte development may play an important role in the differentiation of hESCs into cardiomyocytes.


Subject(s)
Antimetabolites, Antineoplastic/pharmacology , Azacitidine/pharmacology , Cell Culture Techniques , Cell Differentiation/drug effects , Embryonic Stem Cells/drug effects , Myocytes, Cardiac/physiology , Biomarkers/metabolism , Cell Differentiation/physiology , Cells, Cultured , Embryonic Stem Cells/cytology , Embryonic Stem Cells/physiology , Humans , Molecular Sequence Data , Myocytes, Cardiac/cytology , Patch-Clamp Techniques
9.
Hum Reprod ; 21(2): 405-12, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16239319

ABSTRACT

BACKGROUND: Embryonic stem cells (ESC) maintain their 'stemness' by self-renewal. However, the molecular mechanisms underlying self-renewal of human embryonic stem cells (hESC) remain to be elucidated. In this study, expression profiles of the molecules of developmentally important signalling pathways were investigated to better understand the relationships of the signalling pathways for self-renewal in hESC. METHODS: Two human ESC lines were cultured on mouse embryonic fibroblast (MEF) feeder cells. Gene expression was analysed by RT-PCR, real-time RT-PCR and Western blotting. RESULTS: In the bone morphogenetic protein (BMP4), transforming growth factor (TGF-beta) and fibroblast growth factor (FGF4) signalling pathways, ligands and antagonists were highly expressed in hESC compared with human embryoid body (hEB). Human ESC showed abundant transcripts of intracellular molecules in the Wnt, Hh and Notch signalling pathways. No difference was detected in the expression level of the JAK/STAT signalling molecules between hESC and hEB. Western blot analysis showed that the transcriptional levels of the signalling molecules in hESC were consistent with translational levels. From the real-time PCR analysis, expression levels of some genes, such as Oct3/4, Nodal and beta-catenin, were different between two hESC lines. CONCLUSION: The self-renewal of hESC is probably maintained by coordinated regulation of signalling-specific molecules and in a signalling-specific manner.


Subject(s)
Embryo, Mammalian/cytology , RNA, Messenger/metabolism , Signal Transduction , Stem Cells/metabolism , Animals , Bone Morphogenetic Protein 4 , Bone Morphogenetic Proteins/metabolism , Cell Differentiation , Cell Line , Embryo, Mammalian/metabolism , Embryonic Development , Fibroblast Growth Factor 4/metabolism , Gene Expression Profiling , Hedgehog Proteins , Humans , Mice , Models, Biological , Protein-Tyrosine Kinases/metabolism , Receptors, Notch/metabolism , Reverse Transcriptase Polymerase Chain Reaction , STAT Transcription Factors/metabolism , Signal Transduction/genetics , Stem Cells/cytology , Trans-Activators/metabolism , Transcription, Genetic , Transforming Growth Factor beta/metabolism , Wnt Proteins/metabolism
10.
Exp Mol Med ; 37(5): 399-407, 2005 Oct 31.
Article in English | MEDLINE | ID: mdl-16264264

ABSTRACT

Human embryonic stem cells (hESCs) need feeder cells for their maintenance in an undifferentiated state. In conventional culture systems, mouse embryonic fibroblasts (MEFs) serve as feeder cells to maintain hESCs. However, the use of MEFs elevates the risk of transmitting mouse pathogens and thus limits the potential of hESCs in cell replacement therapy. Consequently, the use of human feeder cells would be an important step forward in this in vitro technology. To address this issue, we used fibroblast-like cells differentiated from the Miz-hES6 hESC line (DiffMiz-hES6) as feeder cells to support the in vitro growth of three hESC lines. Immunofluorescence microscopy and reverse transcription-PCR assessing the expression of undifferentiated hESC markers revealed all three hESC lines were maintained in an undifferentiated state. In vitro proliferation proceeded as efficiently as when the hESCs were cultured on MEFS. Moreover, karyotype analysis revealed the chromosomal normality of the hESC lines and the DiffMiz-hES6 feeders themselves after even 50 passages. Furthermore, the hESC lines maintained their pluripotency since they remained capable of forming embryoid bodies (EBs) in vitro. Thus, hESC-derived fibroblast-like cells successfully support in vitro hESC propagation.


Subject(s)
Cell Culture Techniques/methods , Embryo, Mammalian/cytology , Stem Cells/cytology , Biomarkers/analysis , Cell Differentiation , Cell Proliferation , Cells, Cultured , Fibroblasts/cytology , Humans , Karyotyping , Pluripotent Stem Cells/cytology , Time Factors
11.
Stem Cells ; 23(10): 1502-13, 2005.
Article in English | MEDLINE | ID: mdl-16100000

ABSTRACT

The cell-surface markers used routinely to define the undifferentiated state and pluripotency of human embryonic stem cells (hESCs) are those used in mouse embryonic stem cells (mESCs) because of a lack of markers directly originated from hESC itself. To identify more hESC-specific cell-surface markers, we generated a panel of monoclonal antibodies (MAbs) by immunizing the irradiated cell clumps of hESC line Miz-hES1, and selected 26 MAbs that were able to bind to Miz-hES1 cells but not to mESCs, mouse embryonic fibroblast cells, and STO cells. Most antibodies did not bind to human neural progenitor cells derived from the Miz-hES1 cells, either. Of these, MAb 20-202S (IgG1, kappa) immunoprecipitated a cell-surface protein of 72-kDa from the lysate of biotin-labeled Miz-hES1 cells, which was identified to be heat shock 70-kDa protein 8 isoform 1 (HSPA8) by quadrupole time-of-flight tandem mass spectrometry. Immunocytochemical analyses proved that the HSPA8 protein was also present on the surface of hESC lines Miz-hES4, Miz-hES6, and HSF6. Two-color flow cytometric analysis of Miz-hES1 and HSF6 showed the coexpression of the HSPA8 protein with other hESC markers such as stage-specific embryonic antigen 3 (SSEA3), SSEA4, TRA-1-60, and TRA-1-81. Flow cytometric and Western blot analyses using various cells showed that MAb 20-202S specifically bound to the HSPA8 protein on the surface of Miz-hES1, contrary to other anti-HSP70 antibodies examined. Furthermore, the surface expression of the HSPA8 protein on Miz-hES1 was markedly downregulated upon differentiation. These data indicate that a novel MAb 20-202S recognizes the HSPA8 protein on the surface of hESCs and suggest that the HSPA8 protein is a putative cell-surface marker for undifferentiated hESCs.


Subject(s)
Cell Differentiation , Down-Regulation , HSP70 Heat-Shock Proteins/biosynthesis , Protein Isoforms/biosynthesis , Stem Cells/metabolism , Antibodies, Monoclonal/metabolism , Antigens, Surface/metabolism , Cell Line , Embryo Research , HeLa Cells , Humans , Immunohistochemistry , Mass Spectrometry , Stem Cells/cytology
12.
Science ; 308(5729): 1777-83, 2005 06 17.
Article in English | MEDLINE | ID: mdl-15905366

ABSTRACT

Patient-specific, immune-matched human embryonic stem cells (hESCs) are anticipated to be of great biomedical importance for studies of disease and development and to advance clinical deliberations regarding stem cell transplantation. Eleven hESC lines were established by somatic cell nuclear transfer (SCNT) of skin cells from patients with disease or injury into donated oocytes. These lines, nuclear transfer (NT)-hESCs, grown on human feeders from the same NT donor or from genetically unrelated individuals, were established at high rates, regardless of NT donor sex or age. NT-hESCs were pluripotent, chromosomally normal, and matched the NT patient's DNA. The major histocompatibility complex identity of each NT-hESC when compared to the patient's own showed immunological compatibility, which is important for eventual transplantation. With the generation of these NT-hESCs, evaluations of genetic and epigenetic stability can be made. Additional work remains to be done regarding the development of reliable directed differentiation and the elimination of remaining animal components. Before clinical use of these cells can occur, preclinical evidence is required to prove that transplantation of differentiated NT-hESCs can be safe, effective, and tolerated.


Subject(s)
Blastocyst/cytology , Cell Line , Cloning, Organism , Nuclear Transfer Techniques , Pluripotent Stem Cells/cytology , Adult , Agammaglobulinemia , Cell Differentiation , Child , Child, Preschool , DNA Fingerprinting , Diabetes Mellitus, Type 1 , Epigenesis, Genetic , Ethics Committees, Research , Female , Fibroblasts , HLA Antigens/analysis , Humans , Informed Consent , Karyotyping , Male , Oocyte Donation , Pluripotent Stem Cells/immunology , Spinal Cord Injuries , Stem Cell Transplantation , Tissue and Organ Procurement
13.
Stem Cells ; 23(4): 458-62, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15790765

ABSTRACT

Pluripotent embryonic germ cells (EGCs) can be derived from the culture of primordial germ cells (PGCs). However, there are no reports of gonocytes, following the stage of PGC development, becoming stem cell lines. To analyze the gene expression differences between PGCs and gonocytes, we performed cDNA subtractive hybridization with mouse gonads containing either of the two cell populations. We confirmed that developmental pluripotency associated 5 (Dppa5), originally found in mouse embryonic stem cells (ESCs) and mouse embryonic carcinoma cells (ECCs), was strongly expressed in mouse PGCs and the expression was rapidly downregulated during germ cell development. A human sequence homologous to Dppa5 was identified by bioinformatics approaches. Interestingly, human Dppa5 was expressed only in human PGCs, human EGCs, and human ESCs and was not detected in human ECCs. Its expression was downregulated during induced differentiation of human ESCs. These findings confirmed that Dppa5 is specifically and differentially expressed in human cells that have pluripotency. The results strongly suggest that Dppa5 may have an important role in stemness in human ESCs and EGCs and also can be used as a marker of pluripotent stem cells. Human pluripotent stem cells may have their own ways to be pluripotent, as opposed to the much uniform mouse stem cells.


Subject(s)
Germ Cells/metabolism , Pluripotent Stem Cells/metabolism , Proteins/metabolism , Animals , Cell Differentiation , Cells, Cultured , Embryo, Mammalian/cytology , Female , Gene Expression Regulation, Developmental , Germ Cells/cytology , Humans , Male , Mice , Mice, Inbred ICR , Pluripotent Stem Cells/cytology , Pregnancy , Proteins/genetics , Testis/cytology , Testis/embryology , Testis/metabolism
14.
Mol Cells ; 19(1): 31-8, 2005 Feb 28.
Article in English | MEDLINE | ID: mdl-15750337

ABSTRACT

Human embryonic stem (hES) cells have unique features including unlimited growth capacity, expression of specific markers, normal karyotypes and an ability to differentiate. Many investigators have tried to use hES cells for cell-based therapy, but there is little information about the properties of available hES cell lines. We compared the characteristics of three hES cell lines. The expression of SSEA-1, -3, -4, and APase, was examined by immunocytochemistry, and Oct-4 expression was analyzed by RT-PCR. Differentiation of the hES cells in vitro and in vivo led to the formation of embryoid bodies (EBs) or teratomas. We examined the expression of tissue-specific markers in the differentiated cells by semiquantitative RT-PCR, and the ability of each hES cell line to proliferate was measured by flow cytometry of DNA content and ELISA. The three hES cell lines were similar in morphology, marker expression, and teratoma formation. However there were significant differences (P < 0.05) between the differentiated cells formed by the different cell lines in levels of expression of tissue-specific markers such as renin, kallikrein, Glut-2, beta- and delta-globin, albumin, and alpha1-antitrypsin (alpha1-AT). The hES cell lines also differed in proliferative activity. Our observations should be useful in basic and clinical hES cell research.


Subject(s)
Cell Line , Embryo, Mammalian/cytology , Stem Cells/cytology , Animals , Antigens, Tumor-Associated, Carbohydrate , Cell Differentiation , Cell Lineage , Cell Proliferation , DNA-Binding Proteins/biosynthesis , Ectoderm/metabolism , Endoderm/metabolism , Glycosphingolipids/biosynthesis , Humans , Male , Mesoderm/metabolism , Mice , Mice, SCID , Octamer Transcription Factor-3 , Pluripotent Stem Cells/cytology , Pluripotent Stem Cells/metabolism , Stage-Specific Embryonic Antigens , Stem Cells/physiology , Teratoma/etiology , Teratoma/pathology , Testicular Neoplasms/etiology , Testicular Neoplasms/pathology , Transcription Factors/biosynthesis
15.
Mol Cells ; 19(1): 46-53, 2005 Feb 28.
Article in English | MEDLINE | ID: mdl-15750339

ABSTRACT

Human embryonic stem (hES) cells, unlike most cells derived from adult or fetal human tissues, represent a potentially unlimited source of various cell types for basic clinical research. To meet the increased demand for characterized hES cell lines, we established and characterized nine new lines obtained from frozen-thawed pronucleus-stage embryos. In addition, we improved the derivation efficiency from inner cell masses (to 47.4%) and optimized culture conditions for undifferentiated hES cells. After these cell lines had been maintained for over a year in vitro, they were characterized comprehensively for expression of markers of undifferentiated hES cells, karyotype, and in vitro/in vivo differentiation capacity. All of the cell lines were pluripotent, and one cell line was trisomic for chromosome 3. Improved culture techniques for hES cells should make them a good source for diverse applications in regenerative medicine, but further investigation is needed of their basic biology.


Subject(s)
Blastocyst/cytology , Cell Line , Stem Cells/cytology , Animals , Cell Differentiation , Coculture Techniques/methods , Cryopreservation , DNA Fingerprinting , Embryo Research , Fibroblasts , Humans , Karyotyping , Male , Mice , Mice, SCID , Pluripotent Stem Cells/cytology , Teratoma/pathology , Testicular Neoplasms/pathology
16.
FEBS Lett ; 579(2): 534-40, 2005 Jan 17.
Article in English | MEDLINE | ID: mdl-15642372

ABSTRACT

Although basic fibroblast growth factor (FGF2) is generally included in the media for maintenance of human embryonic stem cells (hESCs), the action of FGF2 in these cells has not been well defined. Here, we determined the roles of FGF2 in maintaining hESC self-renewal. Withdrawal of FGF2 from the media led to acquisition of typical differentiated characteristics in hESCs. In the presence of FGF2, which is normally required for proliferation in an undifferentiated state, inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt/PKB signal stimulated differentiation and attenuated the expression of extracellular matrix (ECM) molecules. We suggest that FGF2 maintains hESC self-renewal by supporting stable expression of ECM molecules through activation of the PI3K/Akt/PKB pathway.


Subject(s)
Embryo, Mammalian/cytology , Fibroblast Growth Factor 2/physiology , Signal Transduction , Stem Cells/enzymology , 3-Phosphoinositide-Dependent Protein Kinases , Cell Differentiation/physiology , Cell Proliferation , Chromones/pharmacology , Extracellular Matrix Proteins/metabolism , Fibroblast Growth Factor 2/pharmacology , Humans , Morpholines/pharmacology , Phosphatidylinositol 3-Kinases/physiology , Phosphoinositide-3 Kinase Inhibitors , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/physiology , Proto-Oncogene Proteins/antagonists & inhibitors , Proto-Oncogene Proteins/physiology , Proto-Oncogene Proteins c-akt , Receptors, Laminin/physiology , Stem Cells/cytology , Stem Cells/drug effects
17.
Biol Reprod ; 72(1): 42-9, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15317691

ABSTRACT

Human embryonic stem (hES) cells are usually established and maintained on mouse embryonic fibroblast (MEFs) feeder layers. However, it is desirable to develop human feeder cells because animal feeder cells are associated with risks such as viral infection and/or pathogen transmission. In this study, we attempted to establish new hES cell lines using human uterine endometrial cells (hUECs) to prevent the risks associated with animal feeder cells and for their eventual application in cell-replacement therapy. Inner cell masses (ICMs) of cultured blastocysts were isolated by immunosurgery and then cultured on mitotically inactivated hUEC feeder layers. Cultured ICMs formed colonies by continuous proliferation and were allowed to proliferate continuously for 40, 50, and 55 passages. The established hES cell lines (Miz-hES-14, -15, and -9, respectively) exhibited typical hES cells characteristics, including continuous growth, expression of specific markers, normal karyotypes, and differentiation capacity. The hUEC feeders have the advantage that they can be used for many passages, whereas MEF feeder cells can only be used as feeder cells for a limited number of passages. The hUECs are available to establish and maintain hES cells, and the high expression of embryotrophic factors and extracellular matrices by hUECs may be important to the efficient growth of hES cells. Clinical applications require the establishment and expansion of hES cells under stable xeno-free culture systems.


Subject(s)
Coculture Techniques/methods , Embryo, Mammalian/cytology , Endometrium/cytology , Stem Cells/cytology , Animals , Antigens, Tumor-Associated, Carbohydrate , Biomarkers/metabolism , Blastocyst/cytology , Cell Culture Techniques , Cell Line , Cell Proliferation , Cells, Cultured , Culture Media, Serum-Free , DNA Fingerprinting , Female , Glycosphingolipids/metabolism , Humans , Karyotyping , Male , Mice , Mice, SCID , Pluripotent Stem Cells/cytology , Pluripotent Stem Cells/physiology , Stage-Specific Embryonic Antigens , Teratoma/pathology
18.
Reproduction ; 128(6): 727-35, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15579590

ABSTRACT

Mouse embryonic fibroblasts (MEFs) have been previously used as feeder cells to support the growth of human embryonic stem cells (hESCs). In this study, human adult uterine endometrial cells (hUECs), human adult breast parenchymal cells (hBPCs) and embryonic fibroblasts (hEFs) were tested as feeder cells for supporting the growth of hESCs to prevent the possibility of contamination from animal feeder cells. Cultured hUECs, hBPCs and hEFs were mitotically inactivated and then plated. hESCs (Miz-hES1, NIH registered) initially established on mouse feeder layers were transferred onto each human feeder layer and split every 5 days. The morphology, expression of specific markers and differentiation capacity of hESCs adapted on each human feeder layer were examined. On hUEC, hBPC and hEF feeder layers, hESCs proliferated for more than 90, 50 and 80 passages respectively. Human feeder-based hESCs were positive for stage-specific embryonic antigen (SSEA)-3 and -4, and Apase; they also showed similar differentiation capacity to MEF-based hESCs, as assessed by the formation of teratomas and expression of tissue-specific markers. However, hESCs cultured on hUEC and hEF feeders were slightly thinner and flatter than MEF- or hBPC-based hESCs. Our results suggest that, like MEF feeder layers, human feeder layers can support the proliferation of hESCs without differentiation. Human feeder cells have the advantage of supporting more passages than when MEFs are used as feeder cells, because hESCs can be uniformly maintained in the undifferentiated stage until they pass through senescence. hESCs established and/or maintained under stable xeno-free culture conditions will be helpful to cell-based therapy.


Subject(s)
Breast/cytology , Endometrium/cytology , Stem Cells/cytology , Adult , Animals , Antigens, Tumor-Associated, Carbohydrate , Biomarkers/analysis , Cell Differentiation , Cell Proliferation , Coculture Techniques , Embryo, Mammalian/cytology , Female , Fibroblasts/cytology , Glycosphingolipids/analysis , Humans , Karyotyping , Mice , Stage-Specific Embryonic Antigens , Stem Cells/chemistry , Stem Cells/immunology
19.
Stem Cells ; 22(6): 950-61, 2004.
Article in English | MEDLINE | ID: mdl-15536186

ABSTRACT

Previous reports have indicated that extracellular matrices (ECMs) affect the developmental fate of human embryonic stem cells (hESCs). Specially, type IV collagen and laminin, which belong to a group of macromolecular proteins with a substantial proportion of ECMs, are known to influence the proliferation and differentiation of hES cells. In this study, we evaluated the effects of type IV collagen and laminin in freezing medium on the survival and differentiation rates of hES cells after slow freezing and rapid thawing. The addition of type IV collagen (1 microg/ml) to the freezing medium significantly increased the survival rate of hES cells after thawing compared with that of a control group. The spontaneous differentiation rates of groups treated with type IV collagen (1 microg/ml) or laminin (1 microg/ml) were significantly lower than those of the control group. Frozen-thawed hES cells have currently been cultured for more than 70 passages and retain key properties of hES cells such as morphological characteristics, normal karyotype, marker expression (alkaline phosphatase, SSEA-1, SSEA-3, SSEA-4, TRA-1-60, TRA-1-81, Rex-1, and Oct-4), basement membrane-related gene expression, and the potential to differentiate into derivatives of all three germ layers. This new slow freezing method by ECM treatment is a reliable and effective cryopreservation method for pluripotent hES cells.


Subject(s)
Collagen Type IV/physiology , Cryopreservation/methods , Embryo, Mammalian/cytology , Laminin/physiology , Stem Cells/cytology , Alkaline Phosphatase/biosynthesis , Animals , Antigens, Surface , Antigens, Tumor-Associated, Carbohydrate , Basement Membrane/metabolism , Cell Culture Techniques/methods , Cell Differentiation , Cell Line , Cell Proliferation , Cell Separation , Cell Survival , Cell Transplantation , Culture Media/pharmacology , DNA-Binding Proteins/biosynthesis , Flow Cytometry , Gene Expression , Glycoproteins/biosynthesis , Glycosphingolipids/biosynthesis , Guanine Nucleotide Exchange Factors/biosynthesis , Humans , Karyotyping , Laminin/metabolism , Lewis X Antigen/biosynthesis , Mice , Mice, SCID , Octamer Transcription Factor-3 , Proteoglycans , Reverse Transcriptase Polymerase Chain Reaction , Stage-Specific Embryonic Antigens , Temperature , Teratoma/metabolism , Time Factors , Transcription Factors/biosynthesis
20.
Mol Cells ; 17(2): 309-15, 2004 Apr 30.
Article in English | MEDLINE | ID: mdl-15179047

ABSTRACT

Human embryonic stem (ES) cells and embryonic germ (EG) cells are pluripotent and are invaluable material for in vitro studies of human embryogenesis and cell therapy. So far, only two groups have reported the establishment of human EG cell lines, whereas at least five human ES cell lines have been established. To see if human EG cell lines can be reproducibly established, we isolated primordial germ cells (PGCs) from gonadal ridges and mesenteries (9 weeks post-fertilization) and cultured them on mouse STO cells. As with mouse ES colonies, the PGC-derived cells have given rise to multilayered colonies without any differentiation over a year of continuous culture. They are karyotypically normal and express high levels of alkaline phosphatase, Oct-4, and several cell-surface markers. Histological and immunocytochemical analysis of embryoid bodies (EBs) formed from floating cultures of the PGC-derived cell colonies revealed ectodermal, endodermal, and mesodermal tissues. When the EBs were cultured in the presence of insulin, transferrin, sodium selenite, and fibronectin for 1 week, markers of primitive neuroectoderm were expressed in cells within the EBs as well as in cells growing out from the EBs. These observations indicate that our PGC-derived cells satisfy the criteria for pluripotent stem cells and hence may be EG cells.


Subject(s)
Cell Line , Germ Cells/physiology , Pluripotent Stem Cells/physiology , Transcription Factors , Animals , Biomarkers , Cell Differentiation , Cell Lineage , Cell Size , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Embryo, Mammalian/anatomy & histology , Germ Cells/cytology , Humans , Karyotyping , Mice , Neurons/cytology , Neurons/physiology , Octamer Transcription Factor-3 , Pluripotent Stem Cells/cytology
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