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Articles 1 - 14 of 14

Full-Text Articles in Cell Biology

Tale Factors Use Two Distinct Functional Modes To Control An Essential Zebrafish Gene Expression Program, Franck Ladam, William Stanney, Ian J. Donaldson, Ozge Yildiz, Nicoletta Bobola, Charles G. Sagerstrom Jun 2018

Tale Factors Use Two Distinct Functional Modes To Control An Essential Zebrafish Gene Expression Program, Franck Ladam, William Stanney, Ian J. Donaldson, Ozge Yildiz, Nicoletta Bobola, Charles G. Sagerstrom

Open Access Articles

TALE factors are broadly expressed embryonically and known to function in complexes with transcription factors (TFs) like Hox proteins at gastrula/segmentation stages, but it is unclear if such generally expressed factors act by the same mechanism throughout embryogenesis. We identify a TALE-dependent gene regulatory network (GRN) required for anterior development and detect TALE occupancy associated with this GRN throughout embryogenesis. At blastula stages, we uncover a novel functional mode for TALE factors, where they occupy genomic DECA motifs with nearby NF-Y sites. We demonstrate that TALE and NF-Y form complexes and regulate chromatin state at genes of this GRN ...


Imp3 Stabilization Of Wnt5b Mrna Facilitates Taz Activation In Breast Cancer, Sanjoy Samanta, Santosh Guru, Ameer L. Elaimy, John J. Amante, Jianhong Ou, Jun Yu, Lihua Julie Zhu, Arthur M. Mercurio May 2018

Imp3 Stabilization Of Wnt5b Mrna Facilitates Taz Activation In Breast Cancer, Sanjoy Samanta, Santosh Guru, Ameer L. Elaimy, John J. Amante, Jianhong Ou, Jun Yu, Lihua Julie Zhu, Arthur M. Mercurio

Open Access Articles

Insulin-like growth factor-2 mRNA-binding protein 3 (IMP3) is an oncofetal protein associated with many aggressive cancers and implicated in the function of breast cancer stem cells (CSCs). The mechanisms involved, however, are poorly understood. We observed that IMP3 facilitates the activation of TAZ, a transcriptional co-activator of Hippo signaling that is necessary for the function of breast CSCs. The mechanism by which IMP3 activates TAZ involves both mRNA stability and transcriptional regulation. IMP3 stabilizes the mRNA of an alternative WNT ligand (WNT5B) indirectly by repressing miR145-5p, which targets WNT5B, resulting in TAZ activation by alternative WNT signaling. IMP3 also facilitates ...


Fibroblast Growth Factor Receptor Function In Muscle Stem Cells, Tashi Hackett Jan 2018

Fibroblast Growth Factor Receptor Function In Muscle Stem Cells, Tashi Hackett

Undergraduate Honors Theses

Skeletal muscle has a remarkable ability to regenerate itself following injury and this is reliant upon a group of stem cells known as muscle stem cells Muscle stem cell dysfunction contributes to variety of muscle wasting diseases and insights into mechanisms that regulate MuSC function could lead to new therapies and further our understanding of stem cell biology in general. Fibroblast Growth Factor 2 (FGF2) is a protein that regulates muscle stem cell behavior through stimulation of cell surface tyrosine receptor kinases known as Fibroblast Growth Factor Receptors (Jones, 2001). Activation of the receptors by FGF will induce intracellular signaling ...


Evidence For The Involvement Of Runx1 And Runx2 In Maintenance Of The Breast Cancer Stem Cell Phenotype, Mark Fitzgerald Jan 2018

Evidence For The Involvement Of Runx1 And Runx2 In Maintenance Of The Breast Cancer Stem Cell Phenotype, Mark Fitzgerald

Graduate College Dissertations and Theses

In the United States, metastatic breast cancer kills approximately 40,000 women and 400 men annually, and approximately 200,000 new cases of breast cancer are diagnosed each year. Worldwide, breast cancer is the leading cause of cancer deaths among women. Despite advances in the detection and treatment of metastatic breast cancer, mortality rates from this disease remain high because the fact is that once metastatic, it is virtually incurable. It is widely accepted that a major reason breast cancer continues to exhibit recurrence after remission is that current therapies are insufficient for targeting and eliminating therapy-resistant cancer cells. Emerging ...


The Dlk1-Meg3 Locus In Malignant Cells Of Proposed Primordial Germ Cell Origins., Zachariah Payne Sellers Aug 2017

The Dlk1-Meg3 Locus In Malignant Cells Of Proposed Primordial Germ Cell Origins., Zachariah Payne Sellers

Electronic Theses and Dissertations

Primordial germ cells (PGCs) are hypothesized to deposit hematopoietic stem cells (HSCs) along their migration route through the embryo during the early stages of embryogenesis. PGCs also undergo global chromatin remodeling, including the erasure and reestablishment of genomic imprints, during this migration. While PGCs do not spontaneously form teratomas, their malignant development into germ cell tumors (GCTs) in vivo is often accompanied by the retention of hypomethylation at the IGF2-H19 imprinting control differentially methylated region (DMR). Previous studies in bimaternal embryos determined that proper genomic imprinting at two paternally imprinted loci was necessary for their growth and development: Igf2-H19 and ...


Histone Variant Macroh2a In The Gut And Beyond: A Study Of Intestinal Fortitude, Ryan James Cedeno Jan 2017

Histone Variant Macroh2a In The Gut And Beyond: A Study Of Intestinal Fortitude, Ryan James Cedeno

Publicly Accessible Penn Dissertations

Epigenetic factors guide chromatin remodeling during cell state transitions and confer resistance to genotoxic stressors that could induce deleterious transformations. A particularly peculiar component of the epigenome with emerging roles in fine-tuning cell identity and upholding genomic stability is the structural histone variant macroH2A. Relatively little is currently known about macroH2A’s influence on overall cell developmental potency and less still is known about macroH2A’s contributions to adult stem cell identity and function in vivo. In this work, we use induced pluripotent stem cell (iPSC) reprogramming and the murine intestinal stem cell (ISC) system to model macroH2A’s overall ...


High-Resolution Proteomic And Lipidomic Analysis Of Exosomes And Microvesicles From Different Cell Sources, Reka A. Haraszti, Marie-Cecile Didiot, Ellen Sapp, John D. Leszyk, Scott A. Shaffer, Hannah E. Rockwell, Fei Gao, Niven R. Narain, Marian Difiglia, Michael A. Kiebish, Neil Aronin, Anastasia Khvorova Nov 2016

High-Resolution Proteomic And Lipidomic Analysis Of Exosomes And Microvesicles From Different Cell Sources, Reka A. Haraszti, Marie-Cecile Didiot, Ellen Sapp, John D. Leszyk, Scott A. Shaffer, Hannah E. Rockwell, Fei Gao, Niven R. Narain, Marian Difiglia, Michael A. Kiebish, Neil Aronin, Anastasia Khvorova

Open Access Articles

Extracellular vesicles (EVs), including exosomes and microvesicles (MVs), are explored for use in diagnostics, therapeutics and drug delivery. However, little is known about the relationship of protein and lipid composition of EVs and their source cells. Here, we report high-resolution lipidomic and proteomic analyses of exosomes and MVs derived by differential ultracentrifugation from 3 different cell types: U87 glioblastoma cells, Huh7 hepatocellular carcinoma cells and human bone marrow-derived mesenchymal stem cells (MSCs). We identified 3,532 proteins and 1,961 lipid species in the screen. Exosomes differed from MVs in several different areas: (a) The protein patterns of exosomes were ...


Dna Methylation Directs Genomic Localization Of Mbd2 And Mbd3 In Embryonic Stem Cells, Sarah J. Hainer, Kurtis N. Mccannell, Jun Yu, Ly-Sha Ee, Lihua (Julie) Zhu, Oliver J. Rando, Thomas G. Fazzio Nov 2016

Dna Methylation Directs Genomic Localization Of Mbd2 And Mbd3 In Embryonic Stem Cells, Sarah J. Hainer, Kurtis N. Mccannell, Jun Yu, Ly-Sha Ee, Lihua (Julie) Zhu, Oliver J. Rando, Thomas G. Fazzio

Open Access Articles

Cytosine methylation is an epigenetic and regulatory mark that functions in part through recruitment of chromatin remodeling complexes containing methyl-CpG binding domain (MBD) proteins. Two MBD proteins, Mbd2 and Mbd3, were previously shown to bind methylated or hydroxymethylated DNA, respectively; however, both of these findings have been disputed. Here, we investigated this controversy using experimental approaches and re-analysis of published data and find no evidence for methylation-independent functions of Mbd2 or Mbd3. We show that chromatin localization of Mbd2 and Mbd3 is highly overlapping and, unexpectedly, we find Mbd2 and Mbd3 are interdependent for chromatin association. Further investigation reveals that ...


Regulation Of X-Linked Gene Expression During Early Mouse Development By Rlim, Feng Wang, Jongdae Shin, Jeremy Shea, Jun Yu, Ana Boskovic, Meg Byron, Xiaochun Zhu, Alex K. Shalek, Aviv Regev, Jeanne B. Lawrence, Eduardo M. Torres, Lihua J. Zhu, Oliver J. Rando, Ingolf Bach Sep 2016

Regulation Of X-Linked Gene Expression During Early Mouse Development By Rlim, Feng Wang, Jongdae Shin, Jeremy Shea, Jun Yu, Ana Boskovic, Meg Byron, Xiaochun Zhu, Alex K. Shalek, Aviv Regev, Jeanne B. Lawrence, Eduardo M. Torres, Lihua J. Zhu, Oliver J. Rando, Ingolf Bach

Open Access Articles

Mammalian X-linked gene expression is highly regulated as female cells contain two and male one X chromosome (X). To adjust the X gene dosage between genders, female mouse preimplantation embryos undergo an imprinted form of X chromosome inactivation (iXCI) that requires both Rlim (also known as Rnf12) and the long non-coding RNA Xist. Moreover, it is thought that gene expression from the single active X is upregulated to correct for bi-allelic autosomal (A) gene expression. We have combined mouse genetics with RNA-seq on single mouse embryos to investigate functions of Rlim on the temporal regulation of iXCI and Xist. Our ...


Suppression Of Ischemia In Arterial Occlusive Disease By Jnk-Promoted Native Collateral Artery Development, Kasmir Ramo, Koichi Sugamura, Siobhan M. Craige, John F. Keaney Jr., Roger J. Davis Aug 2016

Suppression Of Ischemia In Arterial Occlusive Disease By Jnk-Promoted Native Collateral Artery Development, Kasmir Ramo, Koichi Sugamura, Siobhan M. Craige, John F. Keaney Jr., Roger J. Davis

Davis Lab Publications

Arterial occlusive diseases are major causes of morbidity and mortality. Blood flow to the affected tissue must be restored quickly if viability and function are to be preserved. We report that disruption of the mixed-lineage protein kinase (MLK) - cJun NH2-terminal kinase (JNK) signaling pathway in endothelial cells causes severe blockade of blood flow and failure to recover in the murine femoral artery ligation model of hindlimb ischemia. We show that the MLK-JNK pathway is required for the formation of native collateral arteries that can restore circulation following arterial occlusion. Disruption of the MLK-JNK pathway causes decreased Dll4/Notch signaling, excessive ...


The Effect Of Small Molecule 390 On Cxcr4 Receptors, Selam B. Zenebe-Gete '14, Shruti R. Topudurti '14, Shum Andrew, Richard J. Miller May 2014

The Effect Of Small Molecule 390 On Cxcr4 Receptors, Selam B. Zenebe-Gete '14, Shruti R. Topudurti '14, Shum Andrew, Richard J. Miller

Student Publications & Research

CXCR4 is the chemokine receptor which aids in chemotaxis of stem cells, such as those in the bone marrow or the brain. SDF-1 is the natural ligand for the CXCR4 receptor. Similarities between novel molecule 390 synthesized by the Miller Lab and SDF-1 make this novel small molecule a possible agonist of the CXCR4 receptor. To determine whether 390 is an agonist to the CXCR4 receptor, we transfected cells with CXCR4 and exposed them to no agonist [vehicle control], SDF-1, or varying concentrations of our agonist drug. Next, we took calcium images using the dye fura-2, which indicates changes in ...


Germline Transgenic Methods For Tracking Cells And Testing Gene Function During Regeneration In The Axolotl, Shahryar Khattak, Maritta Schuez, Tobias Richter, Dunja Knapp, Saori L. Haigo, Tatiana Sandoval-Guzmán, Kristyna Hradlikova, Annett Duemmler, Ryan R. Kerney, Elly M. Tanaka Jun 2013

Germline Transgenic Methods For Tracking Cells And Testing Gene Function During Regeneration In The Axolotl, Shahryar Khattak, Maritta Schuez, Tobias Richter, Dunja Knapp, Saori L. Haigo, Tatiana Sandoval-Guzmán, Kristyna Hradlikova, Annett Duemmler, Ryan R. Kerney, Elly M. Tanaka

Biology Faculty Publications

The salamander is the only tetrapod that regenerates complex body structures throughout life. Deciphering the underlying molecular processes of regeneration is fundamental for regenerative medicine and developmental biology, but the model organism had limited tools for molecular analysis. We describe a comprehensive set of germline transgenic strains in the laboratory-bred salamander Ambystoma mexicanum(axolotl) that open up the cellular and molecular genetic dissection of regeneration. We demonstrate tissue-dependent control of gene expression in nerve, Schwann cells, oligodendrocytes, muscle, epidermis, and cartilage. Furthermore, we demonstrate the use of tamoxifen-induced Cre/loxP-mediated recombination to indelibly mark different cell types. Finally, we ...


Cellular Mechanisms Of Mammalian Liver Regeneration, Kilangsungla Yanger Jan 2013

Cellular Mechanisms Of Mammalian Liver Regeneration, Kilangsungla Yanger

Publicly Accessible Penn Dissertations

ABSTRACT

CELLULAR MECHANISMS OF MAMMALIAN LIVER REGENERATION

Kilangsungla Yanger

Ben Z. Stanger

The liver is an essential organ that aids in metabolic processes, protein synthesis and detoxification of harmful substances. As the centre for detoxification, the liver is able to compensate for this routine damage with its robust regenerative ability. All vertebrate livers, for example, can make up for tissue mass loss (via surgical excision of a portion of the liver) by replication of their differentiated cells within the remnant lobes. These differentiated cells include parenchymal cells such as the hepatocytes and biliary epithelial cells (BECs) and also non-parenchymal cells ...


A Proposal To Test The Effects Of Factor Ecat1 On Pluripotency, From Reprogramming To Differentiation Of Human Somatic Cells, Vritti R. Goel Jan 2012

A Proposal To Test The Effects Of Factor Ecat1 On Pluripotency, From Reprogramming To Differentiation Of Human Somatic Cells, Vritti R. Goel

CMC Senior Theses

The field of stem cell research has been growing more because of the interest in using stem cells to cure diseases and heal injuries. Human embryonic stem cells, because of the controversy surrounding them—and subsequently the difficulties in acquiring samples of the existing aging cell lines—can only be used in limited capacities. While the development of induced pluripotent stem cells in the last decade has allowed the field to progress closer to medical treatments, the low efficiency of reprogramming a somatic cell to a pluripotent state, and the vast molecular and genomic differences between human embryonic stem cells ...