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1.
Regen Med ; 17(4): 203-218, 2022 04.
Article in English | MEDLINE | ID: mdl-35255713

ABSTRACT

Aim: This study aimed to determine knowledge and attitudes toward induced pluripotent stem cell technology and biobanking. Methods: A survey instrument was developed to determine individuals' knowledge of and attitudes toward these technologies. Results: Results from 276 ethnically diverse participants who took the online survey demonstrated significant associations (p ≤ 0. 05) in knowledge by ethnicity and race regarding properties of stem cells, different types of stem cells and previous sample donation behavior. Significantly more Whites 39% (n = 53) compared with Blacks or African-Americans 19.2% (n = 14) had previous knowledge of induced pluripotent stem cells (χ2 = 8.544; p = 0.003) Conclusion: Overall, White race was associated with greater knowledge about stem cells and biobanks and greater willingness to donate samples for future research.


Stem cell biobanks have few samples from minorities for genomic studies. We conducted an online survey to understand knowledge and attitudes toward stem cell biobanks and technologies. Overall, we learned that White race was associated with the greatest knowledge about stem cell biobanks and willingness to contribute tissue samples for biobanks. More education is required so that minorities are willing to contribute tissue samples toward stem cell biobanks. This will help researchers study the genomic bases of disease and pursue translational research toward addressing health inequities.


Subject(s)
Biological Specimen Banks , Health Knowledge, Attitudes, Practice , Genomics , Humans , Stem Cells , Surveys and Questionnaires
2.
Stem Cells Dev ; 30(4): 177-189, 2021 02.
Article in English | MEDLINE | ID: mdl-33406994

ABSTRACT

Extinction rates are rising, and current conservation technologies may not be adequate for reducing species losses. Future conservation efforts may be aided by the generation of induced pluripotent stem cells (iPSCs) from highly endangered species. Generation of a set of iPSCs from multiple members of a species can capture some of the dwindling genetic diversity of a disappearing species. We generated iPSCs from fibroblasts cryopreserved in the Frozen Zoo®: nine genetically diverse individuals of the functionally extinct northern white rhinoceros (Ceratotherium simum cottoni) and two from the closely related southern white rhinoceros (Ceratotherium simum simum). We used a nonintegrating Sendai virus reprogramming method and developed analyses to confirm the cells' pluripotency and differentiation potential. This work is the first step of a long-term interdisciplinary plan to apply assisted reproduction techniques to the conservation of this highly endangered species. Advances in iPSC differentiation may enable generation of gametes in vitro from deceased and nonreproductive individuals that could be used to repopulate the species.


Subject(s)
Biological Specimen Banks , Endangered Species , Extinction, Biological , Genetic Variation , Induced Pluripotent Stem Cells/cytology , Perissodactyla/genetics , Animals , Cell Differentiation/genetics , Cells, Cultured , Cryopreservation/methods , Fibroblasts/cytology , Fibroblasts/metabolism , Gene Expression , Induced Pluripotent Stem Cells/metabolism , Karyotyping , Nanog Homeobox Protein/genetics , Perissodactyla/classification , Reverse Transcriptase Polymerase Chain Reaction , SOXB1 Transcription Factors/genetics , Species Specificity
3.
J Neonatal Perinatal Med ; 14(1): 75-83, 2021.
Article in English | MEDLINE | ID: mdl-32145003

ABSTRACT

BACKGROUND: Gastroschisis is an abdominal wall defect wherein the bowel is herniated into the amniotic fluid. Controversy exists regarding optimal prenatal surveillance strategies that predict fetal well-being and help guide timing of delivery. Our objective was to develop a clinical care pathway for prenatal management of uncomplicated gastroschisis at our institution. METHODS: We performed a review of literature from January 1996 to May 2017 to evaluate prenatal ultrasound (US) markers and surveillance strategies that help determine timing of delivery and optimize outcomes in fetal gastroschisis. RESULTS: A total 63 relevant articles were identified. We found that among the US markers, intraabdominal bowel dilatation, polyhydramnios, and gastric dilatation are potentially associated with postnatal complications. Prenatal surveillance strategy with monthly US starting at 28weeks of gestational age (wGA) and twice weekly non-stress testing beginning at 32wGA is recommended to optimize fetal wellbeing. Timing of delivery should be based on obstetric indications and elective preterm delivery prior to 37wGA is not indicated. CONCLUSIONS: Close prenatal surveillance of fetal gastroschisis is necessary due to the high risk for adverse outcomes including intrauterine fetal demise in the third trimester. Decisions regarding the timing of delivery should take into consideration the additional prematurity-associated morbidity.


Subject(s)
Gastroschisis/diagnostic imaging , Prenatal Care/methods , Ultrasonography, Prenatal/methods , Abdominal Wall/abnormalities , Abdominal Wall/diagnostic imaging , Female , Gastroschisis/surgery , Humans , Infant, Newborn , Pregnancy
4.
Nat Commun ; 11(1): 1070, 2020 Feb 21.
Article in English | MEDLINE | ID: mdl-32081845

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

5.
Am J Obstet Gynecol MFM ; 1(4): 100055, 2019 11.
Article in English | MEDLINE | ID: mdl-33345845

ABSTRACT

BACKGROUND: The postpartum period can be a particularly vulnerable time for exposure to opioid medications, and there are currently no consensus guidelines for physicians to follow regarding opioid prescribing during this period. OBJECTIVE: The purpose of this study was to evaluate inter- and intrahospital variability in opioid prescribing patterns in postpartum women and better understand the role of clinical variables in prescribing. STUDY DESIGN: Data were extracted from electronic medical records on 4248 patients who delivered at 6 hospitals across the United States from January 2016 through March 2016. The primary outcome of the study was postpartum opioid prescription at the time of hospital discharge. Age, parity, route of delivery, and hospital were analyzed individually and with multivariate analyses to minimize confounding factors. Statistical methods included χ2 to analyze frequency of opioid prescription by hospital, parity, tobacco use, delivery method, and laceration type. An analysis of variance was used to analyze morphine equivalent dose by hospital. RESULTS: The percentage of women prescribed postpartum opioids varied significantly by hospital, ranging from 27.6% to 70.9% (P <0.001). Oxycodone-acetaminophen was the most commonly prescribed medication (50.3%) with each hospital having its preferred opioid type. Median number of tablets prescribed ranged from 20 to 40 (P < .0001). Primiparous women were more likely to receive opioids than multiparous women when broken down by a parity of 1, 2, 3, 4, and ≥5 (52.8%, 48.0%, 47.6%, 40.1%, and 45.8%, respectively, P = .0005). Among women who had vaginal deliveries, opioid prescription rates were higher in women who experienced either a second-degree laceration (35.5%, P = .0002) or a third-/fourth-degree laceration (59.3%, P < .001). CONCLUSION: Postpartum opioid prescription rates vary widely among hospitals, but providers within the same hospital tend to follow similar prescribing trends. The variation in prescribing found in our study illustrates the need for clear consensus guidelines for postpartum pain management.


Subject(s)
Analgesics, Opioid , Practice Patterns, Physicians' , Analgesics, Opioid/therapeutic use , Delivery, Obstetric , Female , Humans , Pain Management , Postpartum Period , Pregnancy , United States/epidemiology
7.
Bioessays ; 38 Suppl 1: S86-95, 2016 07.
Article in English | MEDLINE | ID: mdl-27417126

ABSTRACT

Human pluripotent stem cells (hPSCs) have the potential to fundamentally change the way that we go about treating and understanding human disease. Despite this extraordinary potential, these cells also have an innate capability to form tumors in immunocompromised individuals when they are introduced in their pluripotent state. Although current therapeutic strategies involve transplantation of only differentiated hPSC derivatives, there is still a concern that transplanted cell populations could contain a small percentage of cells that are not fully differentiated. In addition, these cells have been frequently reported to acquire genetic alterations that, in some cases, are associated with certain types of human cancers. Here, we try to separate the panic from reality and rationally evaluate the true tumorigenic potential of these cells. We also discuss a recent study examining the effect of culture conditions on the genetic integrity of hPSCs. Finally, we present a set of sensible guidelines for minimizing the tumorigenic potential of hPSC-derived cells. © 2016 The Authors. Inside the Cell published by Wiley Periodicals, Inc.


Subject(s)
Cell Transformation, Neoplastic , Neoplasms/pathology , Pluripotent Stem Cells/pathology , Cell Culture Techniques , Genomic Instability , Humans , Neoplasms/genetics , Neoplasms/prevention & control
8.
J Matern Fetal Neonatal Med ; 29(12): 1919-25, 2016.
Article in English | MEDLINE | ID: mdl-26302817

ABSTRACT

OBJECTIVE: To compare the efficacy of an 80 mL double-balloon catheter versus a 30 mL single-balloon catheter for pre-induction cervical ripening. METHODS: We performed a randomized controlled trial of women ≥18 years with a singleton, vertex pregnancy, a reactive non-stress test, and a Bishop score ≤5 comparing an 80 mL double- versus a 30 mL single-balloon catheters for cervical ripening. Women were randomly assigned to the two catheter types, stratified 1:1 by nulliparity or multiparity. The primary outcome was achieving a Bishop score ≥6 at the time of catheter expulsion or removal assessed by chi-squared, stratified by parity. RESULTS: A total of 98 women were included in the analysis (50 in the 80 mL double and 48 in the 30 mL single-balloon catheter groups). Among nulliparous women, a greater proportion of those randomized to the 80 mL double achieved a Bishop score ≥6 at time of catheter removal (88.0% versus 28.0%; p ≤ 0.001) and delivered vaginally (60.0% versus 32.0%; p = 0.047) compared to those with the 30 mL single-balloon catheter. We found no difference by catheter type in achieving a Bishop score ≥6 or vaginal delivery among multiparous women. CONCLUSIONS: These findings suggest the 80 mL double-balloon catheter is more effective than the 30 mL single-balloon catheter for pre-induction cervical ripening and achieving a vaginal delivery in nulliparous women.


Subject(s)
Cervical Ripening , Labor, Induced/instrumentation , Adult , Female , Humans , Labor, Induced/statistics & numerical data , Pregnancy , Young Adult
9.
Sci Rep ; 5: 13317, 2015 Aug 25.
Article in English | MEDLINE | ID: mdl-26304831

ABSTRACT

Many studies have suggested the significance of glycosyltransferase-mediated macromolecule glycosylation in the regulation of pluripotent states in human pluripotent stem cells (hPSCs). Here, we observed that the sialyltransferase ST6GAL1 was preferentially expressed in undifferentiated hPSCs compared to non-pluripotent cells. A lectin which preferentially recognizes α-2,6 sialylated galactosides showed strong binding reactivity with undifferentiated hPSCs and their glycoproteins, and did so to a much lesser extent with differentiated cells. In addition, downregulation of ST6GAL1 in undifferentiated hPSCs led to a decrease in POU5F1 (also known as OCT4) protein and significantly altered the expression of many genes that orchestrate cell morphogenesis during differentiation. The induction of cellular pluripotency in somatic cells was substantially impeded by the shRNA-mediated suppression of ST6GAL1, partially through interference with the expression of endogenous POU5F1 and SOX2. Targeting ST6GAL1 activity with a sialyltransferase inhibitor during cell reprogramming resulted in a dose-dependent reduction in the generation of human induced pluripotent stem cells (hiPSCs). Collectively, our data indicate that ST6GAL1 plays an important role in the regulation of pluripotency and differentiation in hPSCs, and the pluripotent state in human cells can be modulated using pharmacological tools to target sialyltransferase activity.


Subject(s)
Antigens, CD/metabolism , Cell Differentiation/physiology , Lectins/metabolism , N-Acetylneuraminic Acid/metabolism , Pluripotent Stem Cells/cytology , Pluripotent Stem Cells/physiology , Sialyltransferases/metabolism , Enzyme Activation , Gene Expression Regulation, Developmental/physiology , Gene Expression Regulation, Enzymologic/physiology , Glycosylation , Humans
10.
Expert Opin Biol Ther ; 15(5): 679-87, 2015 May.
Article in English | MEDLINE | ID: mdl-25736263

ABSTRACT

INTRODUCTION: Human pluripotent stem cells (hPSCs) promise for the future of regenerative medicine. The structural and biochemical diversity associated with glycans makes them a unique type of macromolecule modification that is involved in the regulation of a vast array of biochemical events and cellular activities including pluripotency in hPSCs. The primary focus of this review article is to highlight recent advances in stem cell research from a glycobiological perspective. We also discuss how our understanding of glycans and glycosylation may help overcome barriers hindering the clinical application of hPSC-derived cells. AREAS COVERED: A literature survey using NCBI-PubMed and Google Scholar was performed in 2014. EXPERT OPINION: Regenerative medicine hopes to provide novel strategies to combat human disease and tissue injury that currently lack effective therapies. Although progress in this field is accelerating, many critical issues remain to be addressed in order for cell-based therapy to become a practical and safe treatment option. Emerging evidence suggests that protein glycosylation may significantly influence the regulation of cellular pluripotency, and that the exploitation of protein glycosylation in hPSCs and their differentiated derivatives may lead to transformative and translational discoveries for regenerative medicine. In addition, hPSCs represent a novel research platform for investigating glycosylation-related disease.


Subject(s)
Pluripotent Stem Cells/transplantation , Regenerative Medicine/trends , Stem Cell Transplantation/trends , Cell Differentiation/physiology , Embryonic Stem Cells/physiology , Embryonic Stem Cells/transplantation , Glycosylation , Humans , Pluripotent Stem Cells/physiology , Regenerative Medicine/methods , Stem Cell Transplantation/methods
11.
Genomics ; 104(5): 358-67, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25179373

ABSTRACT

5-hydroxymethylcytosine (5hmC), an oxidized derivative of 5-methylcytosine (5mC), has been implicated as an important epigenetic regulator of mammalian development. Current procedures use DNA sequencing methods to discriminate 5hmC from 5mC, limiting their accessibility to the scientific community. Here we report a method that combines TET-assisted bisulfite conversion with Illumina 450K DNA methylation arrays for a low-cost high-throughput approach that distinguishes 5hmC and 5mC signals at base resolution. Implementing this approach, termed "TAB-array", we assessed DNA methylation dynamics in the differentiation of human pluripotent stem cells into cardiovascular progenitors and neural precursor cells. With the ability to discriminate 5mC and 5hmC, we identified a large number of novel dynamically methylated genomic regions that are implicated in the development of these lineages. The increased resolution and accuracy afforded by this approach provides a powerful means to investigate the distinct contributions of 5mC and 5hmC in human development and disease.


Subject(s)
5-Methylcytosine/metabolism , Cytosine/analogs & derivatives , Pluripotent Stem Cells/metabolism , Sequence Analysis, DNA/methods , Cell Differentiation , Cells, Cultured , Cytosine/metabolism , DNA Methylation , Epigenesis, Genetic , Humans , Molecular Sequence Data , Myoblasts, Cardiac/metabolism , Neural Stem Cells
12.
Nat Commun ; 5: 4430, 2014 Jul 18.
Article in English | MEDLINE | ID: mdl-25034944

ABSTRACT

Down's syndrome (DS), caused by trisomy of human chromosome 21, is the most common genetic cause of intellectual disability. Here we use induced pluripotent stem cells (iPSCs) derived from DS patients to identify a role for astrocytes in DS pathogenesis. DS astroglia exhibit higher levels of reactive oxygen species and lower levels of synaptogenic molecules. Astrocyte-conditioned medium collected from DS astroglia causes toxicity to neurons, and fails to promote neuronal ion channel maturation and synapse formation. Transplantation studies show that DS astroglia do not promote neurogenesis of endogenous neural stem cells in vivo. We also observed abnormal gene expression profiles from DS astroglia. Finally, we show that the FDA-approved antibiotic drug, minocycline, partially corrects the pathological phenotypes of DS astroglia by specifically modulating the expression of S100B, GFAP, inducible nitric oxide synthase, and thrombospondins 1 and 2 in DS astroglia. Our studies shed light on the pathogenesis and possible treatment of DS by targeting astrocytes with a clinically available drug.


Subject(s)
Astrocytes/physiology , Down Syndrome/physiopathology , Induced Pluripotent Stem Cells/physiology , Animals , Astrocytes/drug effects , Case-Control Studies , Cell Differentiation , Cell Survival , Cell Transplantation/methods , Culture Media, Conditioned/pharmacology , Down Syndrome/genetics , Gene Expression Profiling , Glial Fibrillary Acidic Protein/metabolism , Homeodomain Proteins/genetics , Humans , Induced Pluripotent Stem Cells/transplantation , Mice, Inbred C57BL , Mice, Mutant Strains , Minocycline/pharmacology , Neural Stem Cells/physiology , Neurons/cytology , Neurons/physiology , Nitric Oxide Synthase Type II/genetics , Nitric Oxide Synthase Type II/metabolism , S100 Calcium Binding Protein beta Subunit/genetics , S100 Calcium Binding Protein beta Subunit/metabolism , Thrombospondin 1/metabolism , Thrombospondins/metabolism
13.
Cell Res ; 24(2): 143-60, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24217768

ABSTRACT

Post-translational modifications (PTMs) are known to be essential mechanisms used by eukaryotic cells to diversify their protein functions and dynamically coordinate their signaling networks. Defects in PTMs have been linked to numerous developmental disorders and human diseases, highlighting the importance of PTMs in maintaining normal cellular states. Human pluripotent stem cells (hPSCs), including embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs), are capable of self-renewal and differentiation into a variety of functional somatic cells; these cells hold a great promise for the advancement of biomedical research and clinical therapy. The mechanisms underlying cellular pluripotency in human cells have been extensively explored in the past decade. In addition to the vast amount of knowledge obtained from the genetic and transcriptional research in hPSCs, there is a rapidly growing interest in the stem cell biology field to examine pluripotency at the protein and PTM level. This review addresses recent progress toward understanding the role of PTMs (glycosylation, phosphorylation, acetylation and methylation) in the regulation of cellular pluripotency.


Subject(s)
Pluripotent Stem Cells/metabolism , Acetylation , Animals , Cell Differentiation , Embryonic Stem Cells/cytology , Embryonic Stem Cells/metabolism , Glycosylation , Humans , Methylation , Phosphorylation , Pluripotent Stem Cells/cytology , Regenerative Medicine , Signal Transduction , Transcription Factors/genetics , Transcription Factors/metabolism
14.
J Biol Chem ; 289(8): 4578-84, 2014 Feb 21.
Article in English | MEDLINE | ID: mdl-24362040

ABSTRACT

Human pluripotent stem cells (hPSCs) are known to acquire genomic changes as they proliferate and differentiate. Despite concerns that these changes will compromise the safety of hPSC-derived cell therapy, there is currently scant evidence linking the known hPSC genomic abnormalities with malignancy. For the successful use of hPSCs for clinical applications, we will need to learn to distinguish between innocuous genomic aberrations and those that may cause tumors. To minimize any effects of acquired mutations on cell therapy, we strongly recommend that cells destined for transplant be monitored throughout their preparation using a high-resolution method such as SNP genotyping.


Subject(s)
Genomic Instability/genetics , Pluripotent Stem Cells/metabolism , Translational Research, Biomedical , Carcinogenesis/genetics , Carcinogenesis/pathology , Clinical Trials as Topic , Genetic Variation , Humans , Pluripotent Stem Cells/cytology
15.
J Cell Sci ; 126(Pt 17): 3848-61, 2013 Sep 01.
Article in English | MEDLINE | ID: mdl-23813959

ABSTRACT

The differentiation of human pluripotent stem cells (hPSCs) to insulin-expressing beta islet-like cells is a promising in vitro model system for studying the molecular signaling pathways underlying beta cell differentiation, as well as a potential source of cells for the treatment of type 1 diabetes. MicroRNAs (miRNAs) are a class of small non-coding RNAs that regulate many biological processes, including cellular differentiation. We studied the miRNA and mRNA expression profiles of hPSCs at five stages of in vitro differentiation along the pancreatic beta cell lineage (definitive endoderm, primitive gut tube, posterior foregut, pancreatic progenitor and hormone-expressing endocrine cells) in the context of samples of primary human fetal pancreas and purified adult islet cells using microarray analysis. Bioinformatic analysis of the resulting data identified a unique miRNA signature in differentiated beta islet cells, and predicted the effects of key miRNAs on mRNA expression. Many of the predicted miRNA-mRNA interactions involved mRNAs known to play key roles in the epithelial-mesenchymal transition process and pancreatic differentiation. We validated a subset of the predictions using qRT-PCR, luciferase reporter assays and western blotting, including the known interaction between miR-200 and ZEB2 (involved in epithelial-mesenchymal transition) and the novel interaction between miR-200 and SOX17 (a key transcription factor in specification of definitive endoderm). In addition, we found that miR-30d and let-7e, two miRNAs induced during differentiation, regulated the expression of RFX6, a transcription factor that directs pancreatic islet formation. These findings suggest that precise control of target mRNA expression by miRNAs ensures proper lineage specification during pancreatic development.


Subject(s)
Homeodomain Proteins/metabolism , Insulin-Secreting Cells/metabolism , MicroRNAs/metabolism , Pluripotent Stem Cells/metabolism , Repressor Proteins/metabolism , SOXF Transcription Factors/metabolism , Cell Differentiation/genetics , Cell Differentiation/physiology , Cell Lineage , Cell- and Tissue-Based Therapy , Cells, Cultured , DNA-Binding Proteins/biosynthesis , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Diabetes Mellitus, Type 1/therapy , Epithelial-Mesenchymal Transition/physiology , Gene Expression Profiling , Gene Expression Regulation, Developmental , Homeodomain Proteins/biosynthesis , Homeodomain Proteins/genetics , Humans , MicroRNAs/genetics , Pancreas/embryology , RNA, Messenger/genetics , Regulatory Factor X Transcription Factors , Repressor Proteins/biosynthesis , Repressor Proteins/genetics , SOXF Transcription Factors/biosynthesis , SOXF Transcription Factors/genetics , Transcription Factors/biosynthesis , Transcription Factors/genetics , Transcription Factors/metabolism , Zinc Finger E-box Binding Homeobox 2
16.
Chimerism ; 4(4): 136-8, 2013.
Article in English | MEDLINE | ID: mdl-23723084

ABSTRACT

Fetal cells transfer to the mother during pregnancy and can persist long-term as microchimerism. Acquisition of microchimerism may also occur during pregnancy loss, either miscarriage or pregnancy termination. Because nearly half of all pregnancies end in loss, we recently investigated the magnitude of fetal cell transfer during pregnancy loss and whether obstetric clinical factors impacted cell transfer. Prospective measurement of fetal cellular microchimerism before and after miscarriage and termination of pregnancy demonstrated a significant transfer of fetal cells in these pregnancies, with higher concentrations of fetal microchimerism in pregnancy termination vs. miscarriage and in those that were managed surgically vs. medically. The frequency of pregnancy loss as a proportion of all pregnancies, and the overrepresentation of fetal genetic abnormalities in pregnancy loss suggest that the resultant acquisition of fetal microchimerism could have a unique and substantial impact on women's health.


Subject(s)
Abortion, Induced , Abortion, Spontaneous/genetics , Chimerism/embryology , Maternal-Fetal Exchange , Abortion, Spontaneous/pathology , Female , Fetus , Humans , Male , Pregnancy , Prospective Studies
18.
J Neurosci ; 32(46): 16213-22, 2012 Nov 14.
Article in English | MEDLINE | ID: mdl-23152605

ABSTRACT

Neural progenitor cells, neurons, and glia of the normal vertebrate brain are diversely aneuploid, forming mosaics of intermixed aneuploid and euploid cells. The functional significance of neural mosaic aneuploidy is not known; however, the generation of aneuploidy during embryonic neurogenesis, coincident with caspase-dependent programmed cell death (PCD), suggests that a cell's karyotype could influence its survival within the CNS. To address this hypothesis, PCD in the mouse embryonic cerebral cortex was attenuated by global pharmacological inhibition of caspases or genetic removal of caspase-3 or caspase-9. The chromosomal repertoire of individual brain cells was then assessed by chromosome counting, spectral karyotyping, fluorescence in situ hybridization, and DNA content flow cytometry. Reducing PCD resulted in markedly enhanced mosaicism that was comprised of increased numbers of cells with the following: (1) numerical aneuploidy (chromosome losses or gains); (2) extreme forms of numerical aneuploidy (>5 chromosomes lost or gained); and (3) rare karyotypes, including those with coincident chromosome loss and gain, or absence of both members of a chromosome pair (nullisomy). Interestingly, mildly aneuploid (<5 chromosomes lost or gained) populations remained comparatively unchanged. These data demonstrate functional non-equivalence of distinguishable aneuploidies on neural cell survival, providing evidence that somatically generated, cell-autonomous genomic alterations have consequences for neural development and possibly other brain functions.


Subject(s)
Aneuploidy , Caspases/physiology , Cell Death/physiology , Cerebral Cortex/embryology , Amino Acid Chloromethyl Ketones/pharmacology , Animals , Apoptosis/physiology , Caspase 3/genetics , Caspase 3/physiology , Caspase 9/genetics , Caspase 9/physiology , Cerebral Cortex/cytology , Cerebral Cortex/enzymology , DNA/biosynthesis , DNA/genetics , Female , Flow Cytometry , Genotype , In Situ Hybridization, Fluorescence , Karyotyping , Male , Metaphase/drug effects , Mice , Mice, Inbred C57BL , Mice, Knockout , Mitosis/physiology , Pregnancy , Sex Determination Processes/physiology
19.
J Vis Exp ; (57): e3177, 2011 Nov 07.
Article in English | MEDLINE | ID: mdl-22158256

ABSTRACT

Pluripotent stem cells (PSCs) have the unique characteristic that they can differentiate into cells from all three germ layers. This makes them a potentially valuable tool for the treatment of many different diseases. With the advent of induced pluripotent stem cells (iPSCs) and continuing research with human embryonic stem cells (hESCs) there is a need for assays that can demonstrate that a particular cell line is pluripotent. Germline transmission has been the gold standard for demonstrating the pluripotence of mouse embryonic stem cell (mESC) lines(1,2,3). Using this assay, researchers can show that a mESC line can make all cell types in the embryo including germ cells(4). With the generation of human ESC lines(5,6), the appropriate assay to prove pluripotence of these cells was unclear since human ESCs cannot be tested for germline transmission. As a surrogate, the teratoma assay is currently used to demonstrate the pluripotency of human pluripotent stem cells (hPSCs)(7,8,9). Though this assay has recently come under scrutiny and new technologies are being actively explored, the teratoma assay is the current gold standard(7). In this assay, the cells in question are injected into an immune compromised mouse. If the cells are pluripotent, a teratoma will eventually develop and sections of the tumor will show tissues from all 3 germ layers(10). In the teratoma assay, hPSCs can be injected into different areas of the mouse. The most common injection sites include the testis capsule, the kidney capsule, the liver; or into the leg either subcutaneously or intramuscularly(11). Here we describe a robust protocol for the generation of teratomas from hPSCs using the testis capsule as the site for tumor growth.


Subject(s)
Cell Transformation, Neoplastic/pathology , Neoplastic Stem Cells/pathology , Pluripotent Stem Cells/pathology , Teratoma/pathology , Testicular Neoplasms/pathology , Animals , Male , Mice , Mice, SCID
20.
Cell Res ; 21(11): 1551-63, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21894191

ABSTRACT

Rapid and dependable methods for isolating human pluripotent stem cell (hPSC) populations are urgently needed for quality control in basic research and in cell-based therapy applications. Using lectin arrays, we analyzed glycoproteins extracted from 26 hPSC samples and 22 differentiated cell samples, and identified a small group of lectins with distinctive binding signatures that were sufficient to distinguish hPSCs from a variety of non-pluripotent cell types. These specific biomarkers were shared by all the 12 human embryonic stem cell and the 14 human induced pluripotent stem cell samples examined, regardless of the laboratory of origin, the culture conditions, the somatic cell type reprogrammed, or the reprogramming method used. We demonstrated a practical application of specific lectin binding by detecting hPSCs within a differentiated cell population with lectin-mediated staining followed by fluorescence microscopy and flow cytometry, and by enriching and purging viable hPSCs from mixed cell populations using lectin-mediated cell separation. Global gene expression analysis showed pluripotency-associated differential expression of specific fucosyltransferases and sialyltransferases, which may underlie these differences in protein glycosylation and lectin binding. Taken together, our results show that protein glycosylation differs considerably between pluripotent and non-pluripotent cells, and demonstrate that lectins may be used as biomarkers to monitor pluripotency in stem cell populations and for removal of viable hPSCs from mixed cell populations.


Subject(s)
Biomarkers/metabolism , Glycomics , Lectins/metabolism , Pluripotent Stem Cells/cytology , Pluripotent Stem Cells/metabolism , Biotin/chemistry , Biotin/metabolism , Cell Separation , Cells, Cultured , Embryonic Stem Cells/cytology , Fucosyltransferases/metabolism , Gene Expression Profiling , Glycosylation , Humans , Induced Pluripotent Stem Cells/cytology , Lectins/chemistry , Protein Array Analysis , Protein Binding , Sialyltransferases/metabolism
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