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Eirini P. Papapetrou

Bio: Eirini P. Papapetrou is an academic researcher from Icahn School of Medicine at Mount Sinai. The author has contributed to research in topics: Induced pluripotent stem cell & Reprogramming. The author has an hindex of 25, co-authored 64 publications receiving 7010 citations. Previous affiliations of Eirini P. Papapetrou include University of Patras & Kettering University.


Papers
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Journal ArticleDOI
TL;DR: Noggin/SB431542-based neural induction should facilitate the use of hES and hiPS cells in regenerative medicine and disease modeling and obviate the need for protocols based on stromal feeders or embryoid bodies.
Abstract: Current neural induction protocols for human embryonic stem (hES) cells rely on embryoid body formation, stromal feeder co-culture or selective survival conditions. Each strategy has considerable drawbacks, such as poorly defined culture conditions, protracted differentiation and low yield. Here we report that the synergistic action of two inhibitors of SMAD signaling, Noggin and SB431542, is sufficient to induce rapid and complete neural conversion of >80% of hES cells under adherent culture conditions. Temporal fate analysis reveals the appearance of a transient FGF5(+) epiblast-like stage followed by PAX6(+) neural cells competent to form rosettes. Initial cell density determines the ratio of central nervous system and neural crest progeny. Directed differentiation of human induced pluripotent stem (hiPS) cells into midbrain dopamine and spinal motoneurons confirms the robustness and general applicability of the induction protocol. Noggin/SB431542-based neural induction should facilitate the use of hES and hiPS cells in regenerative medicine and disease modeling and obviate the need for protocols based on stromal feeders or embryoid bodies.

3,152 citations

Journal ArticleDOI
17 Sep 2009-Nature
TL;DR: The derivation of patient-specific FD-iPSCs and the directed differentiation into cells of all three germ layers including peripheral neurons are reported, illustrating the promise of iPSC technology for gaining new insights into human disease pathogenesis and treatment.
Abstract: The isolation of human induced pluripotent stem cells (iPSCs) offers a new strategy for modelling human disease. Recent studies have reported the derivation and differentiation of disease-specific human iPSCs. However, a key challenge in the field is the demonstration of disease-related phenotypes and the ability to model pathogenesis and treatment of disease in iPSCs. Familial dysautonomia (FD) is a rare but fatal peripheral neuropathy, caused by a point mutation in the IKBKAP gene involved in transcriptional elongation. The disease is characterized by the depletion of autonomic and sensory neurons. The specificity to the peripheral nervous system and the mechanism of neuron loss in FD are poorly understood owing to the lack of an appropriate model system. Here we report the derivation of patient-specific FD-iPSCs and the directed differentiation into cells of all three germ layers including peripheral neurons. Gene expression analysis in purified FD-iPSC-derived lineages demonstrates tissue-specific mis-splicing of IKBKAP in vitro. Patient-specific neural crest precursors express particularly low levels of normal IKBKAP transcript, suggesting a mechanism for disease specificity. FD pathogenesis is further characterized by transcriptome analysis and cell-based assays revealing marked defects in neurogenic differentiation and migration behaviour. Furthermore, we use FD-iPSCs for validating the potency of candidate drugs in reversing aberrant splicing and ameliorating neuronal differentiation and migration. Our study illustrates the promise of iPSC technology for gaining new insights into human disease pathogenesis and treatment.

892 citations

Journal ArticleDOI
TL;DR: PluriTest is reported, a robust open-access bioinformatic assay of pluripotency in human cells based on their gene expression profiles that allows for indirect methods such as differentiation into teratomas in immunodeficient mice.
Abstract: Pluripotent stem cells (PSCs) are defined by their potential to generate all cell types of an organism. The standard assay for pluripotency of mouse PSCs is cell transmission through the germline, but for human PSCs researchers depend on indirect methods such as differentiation into teratomas in immunodeficient mice. Here we report PluriTest, a robust open-access bioinformatic assay of pluripotency in human cells based on their gene expression profiles.

444 citations

Journal ArticleDOI
TL;DR: It is shown that maturation of miR-451, a functional miRNA that is perfectly conserved among vertebrates, is independent of Dicer, and the mir-451 backbone is amenable to reprogramming, permitting vector-driven expression of diverse functional miRNAs in the absence of Dacer.
Abstract: Canonical animal microRNAs (miRNAs) are generated by sequential cleavage of precursor substrates by the Drosha and Dicer RNase III enzymes. Several variant pathways exploit other RNA metabolic activities to generate functional miRNAs. However, all of these pathways culminate in Dicer cleavage, suggesting that this is a unifying feature of miRNA biogenesis. Here, we show that maturation of miR-451, a functional miRNA that is perfectly conserved among vertebrates, is independent of Dicer. Instead, structure-function and knockdown studies indicate that Drosha generates a short pre-mir-451 hairpin that is directly cleaved by Ago2 and followed by resection of its 3′ terminus. We provide stringent evidence for this model by showing that Dicer knockout cells can generate mature miR-451 but not other miRNAs, whereas Ago2 knockout cells reconstituted with wild-type Ago2, but not Slicer-deficient Ago2, can process miR-451. Finally, we show that the mir-451 backbone is amenable to reprogramming, permitting vector-driven expression of diverse functional miRNAs in the absence of Dicer. Beyond the demonstration of an alternative strategy to direct gene silencing, these observations open the way for transgenic rescue of Dicer conditional knockouts.

441 citations

Journal ArticleDOI
TL;DR: 'genomic safe harbours' are discussed — chromosomal locations where therapeutic transgenes can integrate and function in a predictable manner without perturbing endogenous gene activity and promoting cancer.
Abstract: Interactions between newly integrated DNA and the host genome limit the reliability and safety of transgene integration for therapeutic cell engineering and other applications. Although targeted gene delivery has made considerable progress, the question of where to insert foreign sequences in the human genome to maximize safety and efficacy has received little attention. In this Opinion article, we discuss 'genomic safe harbours' - chromosomal locations where therapeutic transgenes can integrate and function in a predictable manner without perturbing endogenous gene activity and promoting cancer.

429 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

01 Aug 2000
TL;DR: Assessment of medical technology in the context of commercialization with Bioentrepreneur course, which addresses many issues unique to biomedical products.
Abstract: BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.

4,833 citations

Journal ArticleDOI
TL;DR: Small non-coding RNAs that function as guide molecules in RNA silencing are involved in nearly all developmental and pathological processes in animals and their dysregulation is associated with many human diseases.
Abstract: MicroRNAs (miRNAs) are small non-coding RNAs that function as guide molecules in RNA silencing. Targeting most protein-coding transcripts, miRNAs are involved in nearly all developmental and pathological processes in animals. The biogenesis of miRNAs is under tight temporal and spatial control, and their dysregulation is associated with many human diseases, particularly cancer. In animals, miRNAs are ∼22 nucleotides in length, and they are produced by two RNase III proteins--Drosha and Dicer. miRNA biogenesis is regulated at multiple levels, including at the level of miRNA transcription; its processing by Drosha and Dicer in the nucleus and cytoplasm, respectively; its modification by RNA editing, RNA methylation, uridylation and adenylation; Argonaute loading; and RNA decay. Non-canonical pathways for miRNA biogenesis, including those that are independent of Drosha or Dicer, are also emerging.

4,256 citations

Journal ArticleDOI
TL;DR: It is shown that this approach can reprogram multiple human cell types to pluripotency with efficiencies that greatly surpass established protocols and represents a safe, efficient strategy for somatic cell reprogramming and directing cell fate that has broad applicability for basic research, disease modeling, and regenerative medicine.

2,627 citations

Journal ArticleDOI
TL;DR: An update on canonical and non-canonical miRNA biogenesis pathways and various mechanisms underlying miRNA-mediated gene regulations and the current knowledge of the dynamics of miRNA action and of the secretion, transfer, and uptake of extracellular miRNAs is provided.
Abstract: MicroRNAs (miRNAs) are a class of non-coding RNAs that play important roles in regulating gene expression. The majority of miRNAs are transcribed from DNA sequences into primary miRNAs and processed into precursor miRNAs, and finally mature miRNAs. In most cases, miRNAs interact with the 3' untranslated region (3' UTR) of target mRNAs to induce mRNA degradation and translational repression. However, interaction of miRNAs with other regions, including the 5' UTR, coding sequence, and gene promoters, have also been reported. Under certain conditions, miRNAs can also activate translation or regulate transcription. The interaction of miRNAs with their target genes is dynamic and dependent on many factors, such as subcellular location of miRNAs, the abundancy of miRNAs and target mRNAs, and the affinity of miRNA-mRNA interactions. miRNAs can be secreted into extracellular fluids and transported to target cells via vesicles, such as exosomes, or by binding to proteins, including Argonautes. Extracellular miRNAs function as chemical messengers to mediate cell-cell communication. In this review, we provide an update on canonical and non-canonical miRNA biogenesis pathways and various mechanisms underlying miRNA-mediated gene regulations. We also summarize the current knowledge of the dynamics of miRNA action and of the secretion, transfer, and uptake of extracellular miRNAs.

2,538 citations