scholarly journals Human embryonic stem cells for brain repair?

Author(s):  
Su-Chun Zhang ◽  
Xue-Jun Li ◽  
M Austin Johnson ◽  
Matthew T Pankratz

Cell therapy has been perceived as the main or ultimate goal of human embryonic stem (ES) cell research. Where are we now and how are we going to get there? There has been rapid success in devising in vitro protocols for differentiating human ES cells to neuroepithelial cells. Progress has also been made to guide these neural precursors further to more specialized neural cells such as spinal motor neurons and dopamine-producing neurons. However, some of the in vitro produced neuronal types such as dopamine neurons do not possess all the phenotypes of their in vivo counterparts, which may contribute to the limited success of these cells in repairing injured or diseased brain and spinal cord in animal models. Hence, efficient generation of neural subtypes with correct phenotypes remains a challenge, although major hurdles still lie ahead in applying the human ES cell-derived neural cells clinically. We propose that careful studies on neural differentiation from human ES cells may provide more immediate answers to clinically relevant problems, such as drug discovery, mechanisms of disease and stimulation of endogenous stem cells.

Development ◽  
1992 ◽  
Vol 116 (Supplement) ◽  
pp. 157-165 ◽  
Author(s):  
R. S. P. Beddington ◽  
P. Rashbass ◽  
V. Wilson

Mouse embryos that are homozygous for the Brachyury (T) deletion die at mid-gestation. They have prominent defects in the notochord, the allantois and the primitive streak. Expression of the T gene commences at the onset of gastrulation and is restricted to the primitive streak, mesoderm emerging from the streak, the head process and the notochord. Genetic evidence has suggested that there may be an increasing demand for T gene function along the rostrocaudal axis. Experiments reported here indicate that this may not be the case. Instead, the gradient in severity of the T defect may be caused by defective mesoderm cell movements, which result in a progressive accumulation of mesoderm cells near the primitive streak. Embryonic stem (ES) cells which are homozygous for the T deletion have been isolated and their differentiation in vitro and in vivo compared with that of heterozygous and wild-type ES cell lines. In +/+ ↔ T/T ES cell chimeras the Brachyury phenotype is not rescued by the presence of wild-type cells and high level chimeras show most of the features characteristic of intact T/T mutants. A few offspring from blastocysts injected with T/T ES cells have been born, several of which had greatly reduced or abnormal tails. However, little or no ES cell contribution was detectable in these animals, either as coat colour pigmentation or by isozyme analysis. Inspection of potential +/+ ↔ T/T ES cell chimeras on the 11th or 12th day of gestation, stages later than that at which intact T/T mutants die, revealed the presence of chimeras with caudal defects. These chimeras displayed a gradient of ES cell colonisation along the rostrocaudal axis with increased colonisation of caudal regions. In addition, the extent of chimerism in ectodermal tissues (which do not invaginate during gastrulation) tended to be higher than that in mesodermal tissues (which are derived from cells invaginating through the primitive streak). These results suggest that nascent mesoderm cells lacking the T gene are compromised in their ability to move away from the primitive streak. This indicates that one function of the T genemay be to regulate cell adhesion or cell motility properties in mesoderm cells. Wild-type cells in +/+ ↔ T/T chimeras appear to move normally to populate trunk and head mesoderm, suggesting that the reduced motility in T/T cells is a cell autonomous defect


Blood ◽  
2006 ◽  
Vol 107 (4) ◽  
pp. 1265-1275 ◽  
Author(s):  
Abby L. Olsen ◽  
David L. Stachura ◽  
Mitchell J. Weiss

Embryonic stem (ES) cells exhibit the remarkable capacity to become virtually any differentiated tissue upon appropriate manipulation in culture, a property that has been beneficial for studies of hematopoiesis. Until recently, the majority of this work used murine ES cells for basic research to elucidate fundamental properties of blood-cell development and establish methods to derive specific mature lineages. Now, the advent of human ES cells sets the stage for more applied pursuits to generate transplantable cells for treating blood disorders. Current efforts are directed toward adapting in vitro hematopoietic differentiation methods developed for murine ES cells to human lines, identifying the key interspecies differences in biologic properties of ES cells, and generating ES cell-derived hematopoietic stem cells that are competent to repopulate adult hosts. The ultimate medical goal is to create patient-specific and generic ES cell lines that can be expanded in vitro, genetically altered, and differentiated into cell types that can be used to treat hematopoietic diseases.


Development ◽  
1998 ◽  
Vol 125 (12) ◽  
pp. 2273-2282 ◽  
Author(s):  
W. Dean ◽  
L. Bowden ◽  
A. Aitchison ◽  
J. Klose ◽  
T. Moore ◽  
...  

In vitro manipulation of preimplantation mammalian embryos can influence differentiation and growth at later stages of development. In the mouse, culture of embryonic stem (ES) cells affects their totipotency and may give rise to fetal abnormalities. To investigate whether this is associated with epigenetic alterations in imprinted genes, we analysed two maternally expressed genes (Igf2r, H19) and two paternally expressed genes (Igf2, U2af1-rs1) in ES cells and in completely ES cell-derived fetuses. Altered allelic methylation patterns were detected in all four genes, and these were consistently associated with allelic changes in gene expression. All the methylation changes that had arisen in the ES cells persisted on in vivo differentiation to fetal stages. Alterations included loss of methylation with biallelic expression of U2af1-rs1, maternal methylation and predominantly maternal expression of Igf2, and biallelic methylation and expression of Igf2r. In many of the ES fetuses, the levels of H19 expression were strongly reduced, and this biallelic repression was associated with biallellic methylation of the H19 upstream region. Surprisingly, biallelic H19 repression was not associated with equal levels of Igf2 expression from both parental chromosomes, but rather with a strong activation of the maternal Igf2 allele. ES fetuses derived from two of the four ES lines appeared developmentally compromised, with polyhydramnios, poor mandible development and interstitial bleeding and, in chimeric fetuses, the degree of chimerism correlated with increased fetal mass. Our study establishes a model for how early embryonic epigenetic alterations in imprinted genes persist to later developmental stages, and are associated with aberrant phenotypes.


2007 ◽  
Vol 19 (1) ◽  
pp. 231
Author(s):  
S. Wang ◽  
X. Tang ◽  
Y. Niu ◽  
H. Chen ◽  
T. Li ◽  
...  

The rabbit, as a laboratory animal model, has several advantages in the study of human physiological disorders. In this study, stable putative pluripotent rabbit embryonic stem cells (rESCs) were derived from in vivo-fertilized and in vitro-cultured blastocysts. The rabbit ICMs were obtained by 0.05% trypsin–0.008% EDTA treatment and mechanical separation; the ES-like cell colonies seen several days later. ICM-derived outgrowths which were treated with 5 mg/mL-1 dispase, followed by 0.05% trypsin–0.008% EDTA, were mechanically disaggregated into small clumps and reseeded on MEFs. The putative ES cell lines maintained expression of pluripotent cells markers and normal XY karyotype for long periods of culture (>1 month). The putative rESCs expressed alkaline phosphatase, transcription factor Oct-4, stage-specific embryonic antigens (SSEA-1, SSEA-3, and SSEA-4), and tumor-related antigens (TRA-1-60 and TRA-1-81). The morphological characteristics of the putative ESCs are closer to those of human ESCs; their high speed of proliferation, however, is closer to that of mouse ESCs. Putative rabbit ESCs were induced to differentiate into many cell types including trophoblast cells, similar to primate ESCs, in vitro, and formed teratomas with derivatives of the 3 major germ layers in vivo when injected into SCID mice. Using RT-PCR measurement, but with some differences in ligands and inhibitors, and comparing with human and mouse ESCs, the putative rabbit ESCs expressed similar genes related to pluripotency (Oct-4, Nanog, SOX2, and UTF-1) and similar genes of FGF, WNT, and TGF signaling pathways related to the proliferation and self-renewal. Our further research work showed that TGF beta and FGF pathways cooperate to maintain pluripotency of rabbit ESCs similar to those of human ES cells.


Blood ◽  
1998 ◽  
Vol 92 (11) ◽  
pp. 4108-4118 ◽  
Author(s):  
Naruyoshi Suwabe ◽  
Satoru Takahashi ◽  
Toru Nakano ◽  
Masayuki Yamamoto

Abstract Although the importance of GATA-1 in both primitive and definitive hematopoietic lineages has been shown in vivo, the precise roles played by GATA-1 during definitive hematopoiesis have not yet been clarified. In vitro differentiation of embryonic stem (ES) cells using OP9 stroma cells can generate primitive and definitive hematopoietic cells separately, and we have introduced a method that separates hematopoietic progenitors and differentiated cells produced in this system. Closer examination showed that the expression of erythroid transcription factors in this system is regulated in a differentiation stage-specific manner. Therefore, we examined differentiation of GATA-1 promoter-disrupted (GATA-1.05) ES cells using this system. Because the GATA-1.05 mice die by 12.5 embryonic days due to the lack of primitive hematopoiesis, the in vitro analysis is an important approach to elucidate the roles of GATA-1 in definitive hematopoiesis. Consistent with the in vivo observation, differentiation of GATA-1.05 mutant ES cells along both primitive and definitive lineages was arrested in this ES cell culture system. Although the maturation-arrested primitive lineage cells did not express detectable amounts of ɛy-globin mRNA, the blastlike cells accumulated in the definitive stage showed β-globin mRNA expression at approximately 70% of the wild type. Importantly, the TER119 antigen was expressed and porphyrin was accumulated in the definitive cells, although the levels of both were reduced to approximately 10%, indicating that maturation of definitive erythroid cells is arrested by the lack of GATA-1 with different timing from that of the primitive erythroid cells. We also found that the hematopoietic progenitor fraction of GATA-1.05 cells contains more colony-forming activity, termed CFU-OP9. These results suggest that theGATA-1.05 mutation resulted in proliferation of proerythroblasts in the definitive lineage.


Reproduction ◽  
2008 ◽  
Vol 135 (6) ◽  
pp. 771-784 ◽  
Author(s):  
Fariborz Izadyar ◽  
Francis Pau ◽  
Joel Marh ◽  
Natalia Slepko ◽  
Tracy Wang ◽  
...  

Spermatogonial stem cells (SSCs) maintain spermatogenesis by self-renewal and generation of spermatogonia committed to differentiation. Under certain in vitro conditions, SSCs from both neonatal and adult mouse testis can reportedly generate multipotent germ cell (mGC) lines that have characteristics and differentiation potential similar to embryonic stem (ES) cells. However, mGCs generated in different laboratories showed different germ cell characteristics, i.e., some retain their SSC properties and some have lost them completely. This raises an important question: whether mGC lines have been generated from different subpopulations in the mouse testes. To unambiguously identify and track germ line stem cells, we utilized a transgenic mouse model expressing green fluorescence protein under the control of a germ cell-specific Pou5f1 (Oct4) promoter. We found two distinct populations among the germ line stem cells with regard to their expression of transcription factor Pou5f1 and c-Kit receptor. Only the POU5F1+/c-Kit+ subset of mouse germ line stem cells, when isolated from either neonatal or adult testes and cultured in a complex mixture of growth factors, generates cell lines that express pluripotent ES markers, i.e., Pou5f1, Nanog, Sox2, Rex1, Dppa5, SSEA-1, and alkaline phosphatase, exhibit high telomerase activity, and differentiate into multiple lineages, including beating cardiomyocytes, neural cells, and chondrocytes. These data clearly show the existence of two distinct populations within germ line stem cells: one destined to become SSC and the other with the ability to generate multipotent cell lines with some pluripotent characteristics. These findings raise interesting questions about the relativity of pluripotency and the plasticity of germ line stem cells.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 495-495
Author(s):  
Ryo Kurita ◽  
Erika Sasaki ◽  
Takashi Hiroyama ◽  
Tomoko Yokoo ◽  
Yukoh Nakazaki ◽  
...  

Abstract Since the successful establishment of human embryonic stem (ES) cell lines in 1998, transplantation of differentiated ES cells to specific organ has been expected to complete its defective function. For the realistic medicine, the preclinical studies using animal model systems including non-human primates are essential. We have already demonstrated that non-human primates of common marmosets (CM) are suitable for the laboratory animal models for preclinical studies of hematopoietic stem cell therapy. In this study, we investigated the in vitro and in vivo differentiation of CM ES cells to hematopoietic cells by exogenous gene transfer methods in order to study the feasibility of future gene modified ES cell therapy. First, we tried various in vitro culture conditions including systems using embryoid bodies or co-culturing with stromal cells to induce hematopoietic cells, but the frequency of inducing hematopoietic cells was very low. The expression of CD45 and gata1 could not be detected in both conditions, suggesting that our culture conditions were incomplete for induction of hematopoietic cells from CM ES cells. Next we examined gene transduction methods by using VSV-G pseudotyped human immunodeficiency virus (HIV) vectors. We constructed the HIV vectors containing hematopoietic genes such as tal1/scl, gata1, gata2, hoxB4 and Lh2 genes under the EF1a promoter and transduced them into CM ES cells. Only in the case of tal1/scl overexpression, not other genes, hematopoietic induction from CM ES cells was dramatically increased and multi-lineage blood cells consisting of erythroid cells, granulocytes, macrophages and megakaryocytes, were confirmed by immunochemical and morphological analyses. Furthermore, RT-PCR results showed that several hematopoietic marker genes including CD34 were expressed higher in the tal1/scl overexpressed ES-derived cells. After the xenotransplantation of ES-derived cells into the immunodeficient mice, CM CD45+ cells and immature erythroids and megakaryocytic cells were observed only in the ES-tal1-injected mice, indicating that enforced expression of tal1/scl into ES cells led to highly efficient hematopoietic cell differentiation in vivo. Taken together, it was suggested that the transduction of exogenous tal1/scl cDNA into ES cells by HIV vector was the promising method for the efficient differentiation from CM ES cells to hematopoietic stem cells. Further examinations are required to determine the long-term hematopoietic reconstitute capacity and the safety of the tal1/scl transduced ES cells in marmoset for the purpose of developing new hematopoietic stem cell therapy.


2018 ◽  
Author(s):  
Ilary Allodi ◽  
Jik Nijssen ◽  
Julio Aguila Benitez ◽  
Christoph Schweingruber ◽  
Andrea Fuchs ◽  
...  

SUMMARYOculomotor neurons, which regulate eye movement, are resilient to degeneration in the lethal motor neuron disease amyotrophic lateral sclerosis (ALS). It would be highly advantageous if motor neuron resilience could be modeled in vitro. Towards this goal, we generated a high proportion of oculomotor neurons from mouse embryonic stem cells through temporal overexpression of Phox2a in neuronal progenitors. We demonstrate, using electrophysiology, immunocytochemistry and RNA sequencing, that in vitro generated neurons are bona fide oculomotor neurons based on their cellular properties and similarity to their in vivo counterpart in rodent and man. We also show that in vitro generated oculomotor neurons display a robust activation of survival-promoting Akt signaling and are more resilient to the ALS-like toxicity of kainic acid than spinal motor neurons. Thus, we can generate bona fide oculomotor neurons in vitro which display a resilience similar to that seen in vivo.


2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Taro Ishigaki ◽  
Kazuhiro Sudo ◽  
Takashi Hiroyama ◽  
Kenichi Miharada ◽  
Haruhiko Ninomiya ◽  
...  

We previously reported that long-lasting in vitro hematopoiesis could be achieved using the cells differentiated from primate embryonic stem (ES) cells. Thus, we speculated that hematopoietic stem cells differentiated from ES cells could sustain long-lasting in vitro hematopoiesis. To test this hypothesis, we investigated whether human hematopoietic stem cells could similarly sustain long-lasting in vitro hematopoiesis in the same culture system. Although the results varied between experiments, presumably due to differences in the quality of each hematopoietic stem cell sample, long-lasting in vitro hematopoiesis was observed to last up to nine months. Furthermore, an in vivo analysis in which cultured cells were transplanted into immunodeficient mice indicated that even after several months of culture, hematopoietic stem cells were still present in the cultured cells. To the best of our knowledge, this is the first report to show that human hematopoietic stem cells can survive in vitro for several months.


2012 ◽  
Vol 24 (1) ◽  
pp. 222
Author(s):  
A. Kusanagi ◽  
J. Yamasaki ◽  
C. Iwatani ◽  
H. Tsuchiya ◽  
R. Torii

Human and mouse embryonic stem (ES) cells are derived from the inner cell mass of preimplantation blastocysts and human ES cells were long thought to be equivalent to mouse ES cells, despite clear morphological difference and different signalling pathways to maintain their pluripotency between these two ES cell types. Mouse ES cells depend on leukemia inhibitory factor (LIF) and bone morphogenic protein 4 (BMP4) signalling, whereas their human counterparts rely on basic fibroblast growth factor (bFGF) and activin A signalling. The biggest difference of two ES cells is the ability of chimera formation and mouse ES cells can contribute chimera but primate ES cells fails to do that. Monkey ES cells in primates only can be tested for chimera formation in vivo due to the ethical issue and cynomolgus monkey is the most common nonhuman primate to be used for the safety study of drug discoveries. The objective of this study was to develop novel cynomolgus monkey ES cells that have similar biological properties with mouse ES cell and our ultimate goal is to establish germline competent nonhuman primate ES cells. Ovarian stimulation and oocyte collection were carried out for the derivation of ES cells as previously described by Torii et al. Briefly, GnRH (0.9 mg/head) was administered to cynomolgus monkey and two weeks later, a micro infusion pump (iPRECIO™, Primetech Corp) contains FSH was implanted subcutaneously. Follicular aspiration was then performed 40 h after hCG injection and metaphase II oocytes were fertilized by intracytoplasmic sperm injection (ICSI). Cynomolgus monkey ES cells were then established under mouse ES cell conditions such as LIF/STAT signalling and a dome tree-dimensional (3D) morphology nonhuman primate ES cells were selected. On the other hands, ES cells that were established with the presence of basic FGF showed conventional layer-type morphology. Dome-type ES cells express pluripotent transcriptional factors such as Oct-3/4, Nonog and Sox2 as same as layer-type ES cells and both ES lines were capable of multilineage differentiations in vitro after embryoid body formation. Dome-type nonhuman ES cells can also form teratomas and differentiated into all three germ layers when grafted into immunodeficiency mice. For fluorescent gene delivery to nonhuman primate ES cells, feeder-free condition was applied and CAG-GFP vector was transfected into ES cells using Neon electroporation system (Invitrogen Inc.) for the tracing ES cells in the transplantation study. In this study, we have established dome-type ES cell lines that similar to mouse ES cells in morphology and signalling pathway. Dome-type nonhuman primate ES cells express pluripotent gene markers and prove their pluripotency both of in vitro and in vivo, in addition, these modifications would be important to create germline competent ES cells.


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