Abstract 340: From Stem Cells to Cardiomyocytes: HDAC1 Induces Cardiovascular Differentiation by Regulating SOX17-BMP2 Expression in Early Development.

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Eneda Hoxha ◽  
Erin Lambers ◽  
Veronica Ramirez ◽  
Prasanna Krishnamurthy ◽  
Suresh Verma ◽  
...  

Cardiomyocytes derived from embryonic and induced pluripotent stem cells (ES/iPS) provide an excellent source for cell replacement therapies following myocardial ischemia. However, some of the obstacles in the realization of the full potential of iPS/ES cells arise from incomplete and poorly understood molecular mechanisms and epigenetic modifications that govern their cardiovascular specific differentiation. We identified Histone Deacetylase 1 (HDAC1) as a crucial regulator in early differentiation of mES and iPS cells. We propose a novel pathway in which HDAC1 regulates cardiovascular differentiation by regulating SOX17 which in turn regulates BMP2 signaling in differentiating pluripotent cells. Utilizing stable HDAC1 knock-down (HDAC1-KD) cell lines, we report an essential role for HDAC1 in deacetylating regulatory regions of pluripotency-associated genes during early cardiovascular differentiation. HDAC1-KD cells show severely repressed cardiomyocyte differentiation potential. We propose a novel HDAC1-BMP2-SOX17 dependent pathway through which deacetylation of pluripotency associated genes leads to their suppression and allows for early cardiovascular-associated genes to be expressed and differentiation to occur. Furthermore, we show that HDAC1 affects DNA methylation both during pluripotency and differentiation and plays a crucial, non-redundant role in cardiovascular specific differentiation and cardiomyocyte maturation. Our data elucidates important differences between ES and iPS HDAC1-KD cells that affect their ability to differentiate into cardiovascular lineages. As varying levels of chromatin modifying enzymes are likely to exist in patient derived iPS cells, understanding the molecular circuitry of these enzymes in ES and iPS cells is critical for their potential therapeutic applications in regenerative medicine. Further research in the molecular mechanisms involved in this process will greatly aid our understanding of the epigenetic circuitry of pluripotency and differentiation in pluripotent cells.

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Eneda Hoxha ◽  
Erin Lambers ◽  
Veronica Ramirez ◽  
Prasanna Krishnamurthy ◽  
Suresh Verma ◽  
...  

Despite advancements in the treatment of myocardial infarction (MI), the majority of patients are at increased risk for developing heart failure due to the loss of cardiomyocytes and microvasculature. Some of the main obstacles in the realization of the full potential of iPS/ES cells arise from incomplete and poorly understood molecular mechanisms and epigenetic modifications that govern their pluripotency and directed differentiation. Real-time array experiments revealed that HDAC1 is highly expressed in pluripotent cells. Additionally the lack of this molecule is embryonic lethal, suggesting it plays a key role in development. Thus, we hypothesized that HDAC1 plays a critical role in directing cardiovascular differentiation of mES and iPS cells in vitro. HDAC1 was knocked down in mES cells (C57BL/6) and iPS cells using a shRNA vector. Differentiation through embryoid body (EB) was induced in wild type mES cells and iPS cells and in their HDAC1-null counterparts and the ability of these cells to differentiate into three early embryonic lineages and more specifically cardiovascular lineage was monitored. EBs lacking HDAC1 differentiated slower and showed delayed suppression of pluripotent genes such as Oct4 and Sox2. ChiP experiments revealed high histone acetylation levels at the promoter regions of these genes during early differentiation. In addition cells lacking HDAC1 showed reduced expression of early markers for all three germ layers. HDAC1-null EBs also showed delayed and reduced spontaneous beating. Expression of cardiomyocite markers as well as markers of other cardiovascular lineages was repressed in HDAC1 -null cells. However, supplementation with BMP2 during early differentiation recovered the ability in the HDAC1-null cells to differentiate into endodermal and mesodermal lineages, but not ectodermal. We propose that HDAC1 plays a critical role in early development and cardiovascular differentiation of mES and iPS cells by repressing pluripotent genes and allowing for expression of early developmental genes such as SOX17 and BMP2. Further research in the molecular mechanisms involved in this process will greatly aid our understanding of the epigenetic circuitry of pluripotency and differentiation in ES and iPS cells.


2012 ◽  
Vol 24 (1) ◽  
pp. 215 ◽  
Author(s):  
J. H. Lee ◽  
Y. M. Lee ◽  
G. H. Maeng ◽  
R. H. Jeon ◽  
T. H. Kim ◽  
...  

Induced pluripotent stem (iPS) cells are somatic cells that have been reprogrammed to a pluripotent state and a great source for regenerative medicine. Several types of human somatic and adult stem cells have been reprogrammed into iPS cells, including mesenchymal stem cells (MSC). Recently, human dental pulp has been considered as a valuable alternative source of MSC (hDP-MSC) with excellent proliferation capacity and multilineage differentiation potential. In this study, our objective was to establish iPS cells from hDP-MSC and evaluate the expression of transcriptional factors and in vitro differentiation potential into mesenchymal lineages. The hMSC were isolated from the dental pulp of male donor (∼18 years old) were cultured in advanced-DMEM supplemented with 10% fetal bovine serum at 37°C, 5% CO2 in a humidified atmosphere. The hDP-MSC at passage 3 were analysed for the expression of MSC-specific surface markers (CD44 and CD90) using flow cytometry and transcriptional factors (Oct4, Nanog and Sox2) by immunofluorescence staining and reverse transcription-polymerase chain reaction (RT-PCR). Differentiation into adipocytes and osteocytes of hDP-MSC was carried out under specific conditions for 2 and 4 weeks, respectively and assessed by cytochemical staining (Oil red O, von Kossa and Alizarin Red S, respectively). iPS cells were generated from hDP-MSC at passage 3 by using pMXs retroviral vector (Addgene, Cambridge, MA, USA) containing cDNA of c-Myc, Klf4, Nanog and Sox2. The iPS cells were evaluated for alkaline phosphatase (AP) activity, expression of human embryonic stem cells (hESC) markers (Rex1, Nanog, Oct4, SSEA-1 and TRA-160) by immunostaining. Isolated hDP-MSC expressed surface markers, such as CD44 and CD90 (86% and 93%, respectively) by flow cytometry and positively stained for transcriptional factors (Oct4, Nanog and Sox2) by immunofluorescence. Further, the cells were capable of differentiating in vitro into adipocytes and osteocytes as demonstrated by Oil red O and von Kossa and Alizarin red S staining, respectively. The iPS cells generated from hDP-MSC were positive for AP staining and clearly expressed the markers specific to hESC, including Rex1, Nanog, Oct4, SSEA-1 and TRA-160. In conclusion, hMSC derived from dental pulp could be successfully reprogrammed into iPS cells by retroviral vector systems and the generated iPS cells shared the similar characteristics of hESC. Therefore, hDP-MSC might be an ideal alternative cell source to derive autologous iPS cells for therapeutic applications. This work was supported by Grant No. 2007031034040 from Bio-organ and Grant No. 200908FHT010204005 from Biogreen21.


2017 ◽  
Vol 4 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Jacob J. Hemmi ◽  
Anuja Mishra ◽  
Peter J. Hornsby

Abstract. Induced pluripotent stem cells (iPS cells) generated by cellular reprogramming from nonhuman primates (NHPs) are of great significance for regenerative medicine and for comparative biology. Autologously derived stem cells would theoretically avoid any risk of rejection due to host–donor mismatch and may bypass the need for immune suppression post-transplant. In order for these possibilities to be realized, reprogramming methodologies that were initially developed mainly for human cells must be translated to NHPs. NHP studies have typically used pluripotent cells generated from young animals and thus risk overlooking complications that may arise from generating iPS cells from donors of other ages. When reprogramming is extended to a wide range of NHP species, available donors may be middle- or old-aged. Here we have pursued these questions by generating iPS cells from donors across the life span of the common marmoset (Callithrix jacchus) and then subjecting them to a directed neural differentiation protocol. The differentiation potential of different clonal cell lines was assessed using the quantitative polymerase chain reaction. The results show that cells derived from older donors often showed less neural marker induction. These deficits were rescued by a 24 h pretreatment of the cells with 0.5 % dimethyl sulfoxide. Another NHP that plays a key role in biological research is the chimpanzee (Pan troglodytes). iPS cells generated from the chimpanzee can be of great interest in comparative in vitro studies. We investigated if similar deficits in differentiation potential might arise in chimpanzee iPS cells reprogrammed using various technologies. The results show that, while some deficits were observed in iPS cell clones generated using three different technologies, there was no clear association with the vector used. These deficits in differentiation were also prevented by a 24 h pretreatment with 0.5 % dimethyl sulfoxide.


2012 ◽  
Vol 24 (1) ◽  
pp. 285
Author(s):  
Jorge A. Piedrahita ◽  
Sehwon Koh ◽  
Natasha Olby

Pluripotent stem cells such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) can give rise to derivatives of all three germ layers and thus have great potential in regenerative medicine. In mice and humans, it has been shown that embryonic and adult fibroblasts can be reprogrammed into pluripotency by introducing four transcription factors, Oct3/4, Klf4, Sox2 and c-Myc (OKSM). In his presentation we will describe the derivation of iPS cells from adult canine fibroblast by retroviral OSKM transduction. The isolated canine iPS cells were expanded in three different iPS culture media (FGF2, LIF and FGF2 plus LIF) and only the cells cultured in FGF2 plus LIF showed strong AP activity expressed pluripotency markers, POU5F1 (OCT4), SOX2, NANOG and LIN28 as well as ES cells-specific genes (PODXL, DPPA5, FGF5, REX1 and LAMP1). In vitro differentiation by formation of embryoid bodies (EBs) and directed differentiation showed cell derivatives of all three germ layers as confirmed by expression for AFP, CXCR4 and SOX17 (endoderm), desmin (DES), vimentin (VIM), MSX1 and BMP2 (mesoderm) and glial fibrillary acidic protein (GFAP), TUJ1, NCAM and bIII-tubulin (TUBB, ectoderm). In vivo, the putative canine iPS cells formed simple teratomas that expressed markers for all three germ layers. In summary, we were able to derive induced pluripotent cells from adult somatic cells by using four transcription factors. The isolated canine iPSCs have similar characteristics to ESCs from other species, but the exact cellular mechanisms behind their unique co-dependency on both FGF and LIF is still unknown. This work was funded by a grant from the America Kennel Club to JAP.


2012 ◽  
Vol 90 (3) ◽  
pp. 317-325 ◽  
Author(s):  
Stefano Pietronave ◽  
Maria Prat

Direct reprogramming of somatic cells into pluripotent cells is an emerging technology for creating patient-specific cells, and potentially opens new scenarios in medical and pharmacological fields. From the discovery of Shinya Yamanaka, who first obtained pluripotent cells from fibroblasts by retrovirus-derived ectopic expression of defined embryonic transcription factors, new methods have been developed to generate safe induced pluripotent stem (iPS) cells without genomic manipulations. This review will focus on the recent advances in iPS technology and their application in pharmacology and medicine.


Reproduction ◽  
2014 ◽  
Vol 147 (6) ◽  
pp. R179-R188 ◽  
Author(s):  
Jingmei Hou ◽  
Shi Yang ◽  
Hao Yang ◽  
Yang Liu ◽  
Yun Liu ◽  
...  

Infertility is a major and largely incurable disease caused by disruption and loss of germ cells. It affects 10–15% of couples, and male factor accounts for half of the cases. To obtain human male germ cells ‘especially functional spermatids’ is essential for treating male infertility. Currently, much progress has been made on generating male germ cells, including spermatogonia, spermatocytes, and spermatids, from various types of stem cells. These germ cells can also be used in investigation of the pathology of male infertility. In this review, we focused on advances on obtaining male differentiated germ cells from different kinds of stem cells, with an emphasis on the embryonic stem (ES) cells, the induced pluripotent stem (iPS) cells, and spermatogonial stem cells (SSCs). We illustrated the generation of male differentiated germ cells from ES cells, iPS cells and SSCs, and we summarized the phenotype for these stem cells, spermatocytes and spermatids. Moreover, we address the differentiation potentials of ES cells, iPS cells and SSCs. We also highlight the advantages, disadvantages and concerns on derivation of the differentiated male germ cells from several types of stem cells. The ability of generating mature and functional male gametes from stem cells could enable us to understand the precise etiology of male infertility and offer an invaluable source of autologous male gametes for treating male infertility of azoospermia patients.


Author(s):  
Abdullah El-Sayes

The isolation of human embryonic stem cells in 1998 has since fueled the ideology that stem cells may eventually be used for human disease therapies as well as the regeneration of tissues and organs. The transformation of somatic cells to a pluripotent state via somatic nuclear transfer and embryonic stem cell fusion brought the scientific community nearer to understanding the molecular mechanisms that govern cellular pluripotency. In 2006, the first induced pluripotent stem (iPS) cell was reported, where a mouse somatic cell was successfully converted to a pluripotent state via transduction of four essential factors. This cellular breakthrough has allowed for robust scientific investigations of human diseases that were once extremely difficult to study. Scientists and pharmaceuticals now use iPS cells as means for disease investigations, drug development and cell or tissue transplantation. There is little doubt that scientific progress on iPS cells will change many aspects of medicine in the next couple of decades.


2015 ◽  
Vol 27 (1) ◽  
pp. 253
Author(s):  
D. Kumar ◽  
T. R. Talluri ◽  
W. A. Kues

The generation of induced pluripotent stem (iPS) cells is a promising approach for innovative cell therapies, as well as for animal biotechnology. The original method requires viral transduction of several reprogramming factors, which may be associated with an increased risk of tumorigenicity due to the preferential integration into active genes. The domestic pig is an attractive large animal model for preclinical testing of safety and efficacy of cell-based therapies. Porcine organs are similar in size and physiology to their human counterparts, and a suitable model for cardiovascular disease, muscular dystrophies, atherosclerosis, wound repair, diabetes, and ophthalmological diseases. Therefore, the present study was carried out to derive porcine iPS cells from transgenic fetuses systemically expressing mCherry (Garrels et al. 2011 PLOS ONE 6) through a nonviral piggyBac transposon. The piggyBac transposon system has several advantages: (i) piggyBac has no bias to integrate in expressed gene-like lenti- or retroviral vectors, (ii) the cargo capacity is >100 kb, (iii) seamless removal is possible, and (iv) the production of transposon plasmid is cost-efficient and does not require S2 safety cabinets. Porcine fetal fibroblasts isolated from CAGGS-mCherry founder porcine line fetuses (passage 2), were co-electroporated with a PB transposon carrying a multigene cassette consisting of human cDNA for OCT4, SOX2, KLF4, c-MYc, NANOG, and LIN28 separated by self-cleaving 2A peptide sequences, driven by a CAGGS promoter and a helper plasmid expressing the pCMV-PB transposase. On Day 6 postelectroporation, morphology of fibroblasts started change to round structure, and on Day 9 loose aggregates of cells developed. Putative iPS cell colonies were cultured, propagated, and characterised through morphology and expression of pluripotency markers, such as AP, OCT4, SSEA-1, and SSEA-4, through immunostaining. Further, various stemness genes, including OCT4, SOX2, NANOG, and UTF, were detected by porcine-specific primers through endpoint RT-PCR. In vitro differentiation potential was assessed by embryoid body (EB) formation. The formed EB exhibited the expression of mCherry in their cells and expressed differentiation markers, such as NESTIN, TUJI, GATA4 and AFP. To test their tumorigenic potential, 1 × 106 iPS cells were injected under the skin of nude mice. An mCherry-positive tumour was recovered 6 weeks later. Presently the tumour is being prepared for histological analysis. This study indicates that piggyBac transposon containing 6 transcription factors is able to reprogram porcine fetal fibroblasts into iPS cells. These cells could be cultured and maintained in vitro for a prolonged period, exhibit characteristics of stem cells, and offer a potential source for future blastocyst complementation experiments.


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