Abstract 4: Porcine Parthenotes as a Model to Evaluate Developmental Potential of Human Inducible Pluripotent Stem Cells

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Naoko Koyano-Nakagawa ◽  
James Dutton ◽  
Mary G Garry ◽  
Daniel J Garry

The use of human induced pluripotent stem cells (hiPSCs) has tremendous potential for regenerative medicine by providing an unlimited source of personalized cells. A number of protocols have been established for efficient differentiation of hiPSCs to the desired lineage in vitro, such as cardiomyocytes and blood. However, the field lacks an in vivo system to evaluate the differentiation potential and quality of hiPSCs. Developmental potential of stem cells derived from experimental animals can be readily assessed by generating blastocyst chimeras and examination of the contribution to the embryos, or by the potential of teratoma formation. However, this is not possible in the case of humans. As a potential solution for this issue, we examined whether porcine parthenotes could be used as an experimental model to test the developmental potential of the hiPSCs. Parthenotes are generated by electrical activation of the oocytes collected at the abattoir and will develop up to gestational day 53 if transferred to a pseudo-pregnant sow. The embryonic culture conditions have also been established and the zygotes can develop normally to the expanded blastocyst stage (day 7 post fertilization/activation), in vitro. We took advantage of this in vitro system and examined the ability of hiPSCs to proliferate and integrate into the parthenogenetic embryos. Parthenogenetic embryos were injected with ten undifferentiated hiPSCs at day 4 (8 cell ~ morula stage) and cultured up to 72 hours. During this period, parthenotes underwent blastocoel cavity formation and hatching. Cell tracing experiments demonstrated that hiPSCs proliferated and integrated into the parthenotes. They retained pluripotency marker expression during this period. hiPSCs and their derivatives were found both in trophoectoderm and embryo proper. We further observed that the hiPSCs underwent cellular proliferation and promoted developmental progression of the parthenote in vitro. In summary, the porcine parthenote model system is an efficient high throughput system to examine the developmental capacity of human stem cell populations.

Reproduction ◽  
2006 ◽  
Vol 131 (5) ◽  
pp. 895-904 ◽  
Author(s):  
Hakan Sagirkaya ◽  
Muge Misirlioglu ◽  
Abdullah Kaya ◽  
Neal L First ◽  
John J Parrish ◽  
...  

Expression of embryonic genes is altered in different culture conditions, which influence developmental potential both during preimplantation and fetal development. The objective of this study was to define the effects of culture conditions on: bovine embryonic development to blastocyst stage, blastocyst cell number, apoptosis and expression patterns of a panel of developmentally important genes. Bovine embryos were culturedin vitroin three culture media containing amino acids, namely potassium simplex optimization medium (KSOMaa), Charles Rosenkrans 1 (CR1aa) and synthetic oviductal fluid (SOFaa). Apoptosis in blastocysts was determined by TUNEL assay and expression profiles of developmentally important genes were assayed by real-time PCR.In vivo-produced bovine blastocysts were used as controls for experiments determining gene expression patterns. While the cleavage rates did not differ, embryos cultured in SOFaa had higher rates of development to blastocyst stage (P< 0.05). Mean cell numbers and percentages of apoptotic cells per blastocyst did not differ among the groups. Expression of the heat shock protein 70 (Hsp70) gene was significantly up-regulated in both CR1aa and KSOMaa when compared with SOFaa (P< 0.001). DNA methyltransferase 3a (Dnmt3a) expression was higher in embryos cultured in CR1aa than in those cultured in SOFaa (P< 0.001). Expression of interferon tau (IF-τ) and insulin-like growth factor II receptor (Igf-2r) genes was significantly up-regulated in KSOMaa when compared with CR1aa (P< 0.001). Gene expression did not differ betweenin vivo-derived blastocysts and theirin vitro-derived counterparts. In conclusion, SOFaa supports higher development to blastocyst stage than KSOMaa and CR1aa, and the culture conditions influence gene expression.


Reproduction ◽  
2002 ◽  
pp. 507-515 ◽  
Author(s):  
TJ King ◽  
J Zhu ◽  
HA Finlayson ◽  
W Bosma ◽  
L Harkness ◽  
...  

Embryo transfer and pregnancy maintenance strategies in pigs were evaluated with reference to situations in which limited numbers of viable embryos or micromanipulated embryos are available, such as pig cloning. Development of embryos with compromised zona pellucida was compared with development of embryos with intact zona pellucida. Micromanipulation had no effect on blastocyst production rates after development in vivo or in vitro, but development in vivo improved the number of embryos reaching the blastocyst stage. Transfer of embryos with compromised zona pellucida resulted in live piglets. Several hormone treatments to maintain pregnancy were tested in a model in which three embryos were transferred into unmated recipient gilts, compared with transfer of three embryos into mated recipients. None of the hormonal treatments resulted in pregnancy rates of more than 25% at term and no more than 9% of transferred embryos survived, in comparison with 50% of the mated recipients successfully carrying 25% of transferred embryos. Lastly, the developmental potential of parthenogenetic embryos was assessed and 62% of transferred embryos resulted in pregnancies, none of which continued beyond day 55 of gestation. After co-transfer of three fertilized embryos with 55-60 parthenogenetic embryos into each of six recipients, two live piglets were delivered. The results from the present study indicate that transfer of zona pellucida compromised embryos can yield litters of normal piglets. In addition, it was demonstrated in a model system involving the transfer of three fertilized embryos into mature gilts that hormonal pregnancy maintenance strategies support a low proportion of embryos to term. Lastly, the present study shows for the first time a comparably effective but novel alternative for pregnancy maintenance in the pig involving the co-transfer of parthenote embryos.


2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Martin Maldonado ◽  
Tianhua Huang ◽  
Jianying Chen ◽  
Ying Zhong

In vitro maturation (IVM) in cumulus oocyte complexes (COCs) can be improved by the presence of human Wharton’s jelly-derived MSCs (hWJ-MSCs), under specific culture conditions. COCs were cultured in twelve different culture systems, composed of four stock media, stock media conditioned with hWJ-MSCs, and stock media in which the oocytes were indirectly cocultured with the hWJ-MSCs. The rates of maturation to meiosis II were compared among the groups. G2-PLUS and coculture with DMEM-F12 were the most efficient systems for the maturation of COCs. The fertilization rate and rate of development to the blastocyst stage were compared between these two groups. Moreover, hWJ-MSC-conditioned media showed no benefits for the COC-IVM. The analysis of OCT4 expression of hWJ-MSCs in G1-PLUS, TYH, and G2-PLUS showed a downregulation of OCT4 by 25.9, 24.7, and 6.6%, respectively, compared to that in hWJ-MSCs cultured in DMEM-F12. Finally, we have demonstrated that two prerequisites appeared to be necessary for the hWJ-MSCs to improve the IVM of COCs: hWJ-MSCs’ differentiation potential and the presence of coordinated paracrine interaction between the stem cells and COCs. Under the appropriate conditions, the paracrine factors produced in the coculture system with DMEM-F12 may help to develop synthetic media for successful in vitro culture of COCs.


Cells ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1650 ◽  
Author(s):  
Christina McKee ◽  
Christina Brown ◽  
G. Rasul Chaudhry

The maintenance and expansion of human embryonic stem cells (ESCs) in two-dimensional (2-D) culture is technically challenging, requiring routine manipulation and passaging. We developed three-dimensional (3-D) scaffolds to mimic the in vivo microenvironment for stem cell proliferation. The scaffolds were made of two 8-arm polyethylene glycol (PEG) polymers functionalized with thiol (PEG-8-SH) and acrylate (PEG-8-Acr) end groups, which self-assembled via a Michael addition reaction. When primed ESCs (H9 cells) were mixed with PEG polymers, they were encapsulated and grew for an extended period, while maintaining their viability, self-renewal, and differentiation potential both in vitro and in vivo. Three-dimensional (3-D) self-assembling scaffold-grown cells displayed an upregulation of core pluripotency genes, OCT4, NANOG, and SOX2. In addition, the expression of primed markers decreased, while the expression of naïve markers substantially increased. Interestingly, the expression of mechanosensitive genes, YAP and TAZ, was also upregulated. YAP inhibition by Verteporfin abrogated the increased expression of YAP/TAZ as well as core and naïve pluripotent markers. Evidently, the 3-D culture conditions induced the upregulation of makers associated with a naïve state of pluripotency in the primed cells. Overall, our 3-D culture system supported the expansion of a homogenous population of ESCs and should be helpful in advancing their use for cell therapy and regenerative medicine.


Author(s):  
Peng Cui ◽  
Ping Zhang ◽  
Lin Yuan ◽  
Li Wang ◽  
Xin Guo ◽  
...  

Hypoxia-inducible factor 1α (HIF-1α) plays pivotal roles in maintaining pluripotency, and the developmental potential of pluripotent stem cells (PSCs). However, the mechanisms underlying HIF-1α regulation of neural stem cell (NSC) differentiation of human induced pluripotent stem cells (hiPSCs) remains unclear. In this study, we demonstrated that HIF-1α knockdown significantly inhibits the pluripotency and self-renewal potential of hiPSCs. We further uncovered that the disruption of HIF-1α promotes the NSC differentiation and development potential in vitro and in vivo. Mechanistically, HIF-1α knockdown significantly enhances mitofusin2 (MFN2)-mediated Wnt/β-catenin signaling, and excessive mitochondrial fusion could also promote the NSC differentiation potential of hiPSCs via activating the β-catenin signaling. Additionally, MFN2 significantly reverses the effects of HIF-1α overexpression on the NSC differentiation potential and β-catenin activity of hiPSCs. Furthermore, Wnt/β-catenin signaling inhibition could also reverse the effects of HIF-1α knockdown on the NSC differentiation potential of hiPSCs. This study provided a novel strategy for improving the directed differentiation efficiency of functional NSCs. These findings are important for the development of potential clinical interventions for neurological diseases caused by metabolic disorders.


2021 ◽  
Vol 22 (19) ◽  
pp. 10430
Author(s):  
Sacha Robert ◽  
Marcus Flowers ◽  
Brenda M. Ogle

Differentiation of pluripotent stem cells to cardiomyocytes is influenced by culture conditions including the extracellular matrices or similar synthetic scaffolds on which they are grown. However, the molecular mechanisms that link the scaffold with differentiation outcomes are not fully known. Here, we determined by immunofluorescence staining and mass spectrometry approaches that extracellular matrix (ECM) engagement by mouse pluripotent stem cells activates critical components of canonical wingless/integrated (Wnt) signaling pathways via kinases of the focal adhesion to drive cardiomyogenesis. These kinases were found to be differentially activated depending on type of ECM engaged. These outcomes begin to explain how varied ECM composition of in vivo tissues with development and in vitro model systems gives rise to different mature cell types, having broad practical applicability for the design of engineered tissues.


2012 ◽  
Vol 24 (1) ◽  
pp. 112 ◽  
Author(s):  
M. T. Zhao ◽  
X. Yang ◽  
K. Lee ◽  
J. Mao ◽  
J. M. Teson ◽  
...  

Skin-derived progenitors (SKP) are capable of generating both neural and mesodermal progeny in vitro: neurons, Schwann cells, adipocytes, osteocytes and chondrocytes, thus exhibiting characteristics similar to embryonic neural crest stem cells. SKP show distinct transcriptional profiles when compared with neurospheres/neural stem cells in the central nervous system (CNS) and skin-derived fibroblasts, indicating a novel type of multipotent stem cell derived from the dermis of the skin. However, it remains unclear whether SKP cells can produce ectoderm and mesoderm lineages or other germ layers in vivo, although oocyte-like structures can be induced from porcine SKP in vitro. Embryonic chimeras are a well-established tool for investigating cell lineage determination and cell potency through normal embryonic development. Thus the purpose of this study was to investigate the in vivo developmental potential of porcine SKP by chimera production. Porcine SKP cells and fibroblasts were isolated from the back skin of Day 35 to 50 GFP transgenic fetuses. Individual cells or clusters of male GFP transgenic SKP and skin-derived GFP-expressing fibroblasts were injected into pre-compact in vitro-fertilized (IVF) embryos, respectively and then transferred into corresponding surrogates 24 h post-injection. Additional injected embryos were cultured in PZM3 medium for another 2 days until the blastocyst stage and subsequently stained with Hoechst 33342. Interestingly, in some of the chimeras the injected SKP cells migrated and dispersed into different locations of the host blastocysts, whereas in others they remained as a cluster of cells within the chimeric blastocysts. In contrast, the fibroblast cells were not observed to spread around the host blastocysts. Two chimeric fetuses were recovered at the middle of gestation and a litter of viable piglets was born. Genomic DNA was extracted from various tissues of chimeric piglets and subjected to PCR amplification. Two chimeric fetuses and 2 out of 6 piglets carried the GFP transgene in SKP-derived chimeras, but GFP was not present in the fibroblast-derived chimeric fetuses (n = 6). Surprisingly, the GFP transgene was present in various tissues of two SKP-derived chimeric piglets, including lung, heart, liver, artery, kidney, brain, skin, muscle, gut, ovary, pancreas and stomach, thus representing the 3 germ layers (ectoderm, mesoderm and endoderm). In addition, SRY was detected in several tissues of the two GFP-positive female chimeric piglets, confirming the chimerism of these piglets. Therefore, it appears that porcine SKP can contribute to various cell types of the 3 germ layers and have a broader developmental potency than previously expected. Alternatively, pre-compact (4-cell and 8-cell stage) embryos may provide a unique environment for reprogramming skin-derived progenitors into a more primitive state by the process of embryonic compaction. This study was funded by NIH National Center for Research Resources (R01RR013438) and Food for the 21st Century at the University of Missouri.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
May Shin Yap ◽  
Kavitha R. Nathan ◽  
Yin Yeo ◽  
Lee Wei Lim ◽  
Chit Laa Poh ◽  
...  

Human pluripotent stem cells (hPSCs) derived from either blastocyst stage embryos (hESCs) or reprogrammed somatic cells (iPSCs) can provide an abundant source of human neuronal lineages that were previously sourced from human cadavers, abortuses, and discarded surgical waste. In addition to the well-known potential therapeutic application of these cells in regenerative medicine, these are also various promising nontherapeutic applications in toxicological and pharmacological screening of neuroactive compounds, as well as forin vitromodeling of neurodegenerative and neurodevelopmental disorders. Compared to alternative research models based on laboratory animals and immortalized cancer-derived human neural cell lines, neuronal cells differentiated from hPSCs possess the advantages of species specificity together with genetic and physiological normality, which could more closely recapitulatein vivoconditions within the human central nervous system. This review critically examines the various potential nontherapeutic applications of hPSC-derived neuronal lineages and gives a brief overview of differentiation protocols utilized to generate these cells from hESCs and iPSCs.


Author(s):  
Luis Covarrubias ◽  
José-Ángel Martínez-Sarmiento ◽  
Concepción Valencia ◽  
Andras Nagy ◽  
David Hernández-García

The amount of proteins of the regulatory pluripotency network can be determinant for somatic cell reprogramming into induced pluripotent stem cells (iPSCs) as well as for the maintenance of pluripotent stem cells (PSCs). Here we report a transposon-based reprogramming system (PB-Booster) that allowed high expression levels of a polycistronic transgene containing Myc, Klf4, Oct4 and Sox2 (MKOS) and showed increased reprogramming efficiency of fresh mouse embryonic fibroblasts (MEFs) into iPSCs under low but not under high MKOS expression levels. In contrast, MEFs after 2 passages derived into similar number of iPSC colonies than fresh MEFs at high MKOS dose but this number was reduced at low MKOS dose. Timing of reprogramming was not affected by MKOS expression levels but, importantly, exogenous MKOS expression in established PSCs caused a significant cell loss. At high but not at low MKOS expression levels, MEFs of the CD1 strain produced more initial cell clusters than iPSCs and, although reprogrammed at a similar efficiency as MEFs of the 129/Sv strain, iPSCs could not be maintained in the absence of exogenous MKOS. In CD1-iPSCs, Oct4, Nanog, Rex1 and Esrrb expression levels were reduced when compared with the levels in PSCs derived from the 129/Sv strain. Culture of CD1-iPSCs in medium with MEK and GSK3ß inhibitors allowed their self-renewal in the absence of exogenous MKOS, but the expression levels of Oct4, Nanog, Rex1 and Esrrb were only partially increased. Despite the reduced levels of those pluripotency factors, CD1-iPSC kept high capacity for contribution to chimeric mouse embryos. Therefore, levels of regulatory pluripotency factors influence reprogramming initiation and PSC maintenance in vitro without affecting their differentiation potential in vivo.


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