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Full-Text Articles in Cell Biology

Leptin Promotes Expression Of Emt-Related Transcription Factors And Invasion In A Src And Fak-Dependent Pathway In Mcf10a Mammary Epithelial Cells, Monserrat Olea-Flores, Miriam Zuniga-Eulogio, Arvey Tacuba-Saavedra, Magdalena Bueno-Salgado, Andrea Sanchez-Carvajal, Yovani Vargas-Santiago, Miguel A. Mendoza-Catalan, Eduardo Perez Salazar, Alejandra Garcia-Hernandez, Teresita Padilla-Benavides, Napoleon Navarro-Tito Sep 2019

Leptin Promotes Expression Of Emt-Related Transcription Factors And Invasion In A Src And Fak-Dependent Pathway In Mcf10a Mammary Epithelial Cells, Monserrat Olea-Flores, Miriam Zuniga-Eulogio, Arvey Tacuba-Saavedra, Magdalena Bueno-Salgado, Andrea Sanchez-Carvajal, Yovani Vargas-Santiago, Miguel A. Mendoza-Catalan, Eduardo Perez Salazar, Alejandra Garcia-Hernandez, Teresita Padilla-Benavides, Napoleon Navarro-Tito

Open Access Articles

Leptin is one of the main adipokines secreted in breast tissue. Leptin promotes epithelial-mesenchymal transition (EMT), cell migration and invasion in epithelial breast cells, leading to tumor progression. Although, the molecular mechanisms that underlie these events are not fully understood, the activation of different signaling pathways appears to be essential. In this sense, the effects of leptin on the activation of kinases like Src and FAK, which regulate signaling pathways that activate the EMT program, are not completely described. Therefore, we investigated the involvement of these kinases using an in vitro model for leptin-induced EMT process in the non-tumorigenic MCF10A ...


A Critical Role Of Vmp1 In Lipoprotein Secretion, Hideaki Morishita, Yan G. Zhao, Norito Tamura, Taki Nishimura, Yuki Kanda, Yuriko Sakamaki, Mitsuyo Okazaki, Dongfang Li, Noboru Mizushima Sep 2019

A Critical Role Of Vmp1 In Lipoprotein Secretion, Hideaki Morishita, Yan G. Zhao, Norito Tamura, Taki Nishimura, Yuki Kanda, Yuriko Sakamaki, Mitsuyo Okazaki, Dongfang Li, Noboru Mizushima

Open Access Articles

Lipoproteins are lipid-protein complexes that are primarily generated and secreted from the intestine, liver, and visceral endoderm and delivered to peripheral tissues. Lipoproteins, which are assembled in the endoplasmic reticulum (ER) membrane, are released into the ER lumen for secretion, but its mechanism remains largely unknown. Here, we show that the release of lipoproteins from the ER membrane requires VMP1, an ER transmembrane protein essential for autophagy and certain types of secretion. Loss of vmp1, but not other autophagy-related genes, in zebrafish causes lipoprotein accumulation in the intestine and liver. Vmp1 deficiency in mice also leads to lipid accumulation in ...


Extensive Ribosome And Rf2 Rearrangements During Translation Termination, Egor Svidritskiy, Gabriel Demo, Anna B. Loveland, Chen Xu, Andrei A. Korostelev Sep 2019

Extensive Ribosome And Rf2 Rearrangements During Translation Termination, Egor Svidritskiy, Gabriel Demo, Anna B. Loveland, Chen Xu, Andrei A. Korostelev

Open Access Articles

Protein synthesis ends when a ribosome reaches an mRNA stop codon. Release factors (RFs) decode the stop codon, hydrolyze peptidyl-tRNA to release the nascent protein, and then dissociate to allow ribosome recycling. To visualize termination by RF2, we resolved a cryo-EM ensemble of E. coli 70S*RF2 structures at up to 3.3 A in a single sample. Five structures suggest a highly dynamic termination pathway. Upon peptidyl-tRNA hydrolysis, the CCA end of deacyl-tRNA departs from the peptidyl transferase center. The catalytic GGQ loop of RF2 is rearranged into a long beta-hairpin that plugs the peptide tunnel, biasing a nascent ...


Diverse Repertoire Of Human Adipocyte Subtypes Develops From Transcriptionally Distinct Mesenchymal Progenitor Cells, So Yun Min, Anand Desai, Zinger Yang, Agastya Sharma, Tiffany Desouza, Ryan Genga, Alper Kucukural, Lawrence M. Lifshitz, Soren Nielsen, Camilla Scheele, Rene Maehr, Manuel Garber, Silvia Corvera Sep 2019

Diverse Repertoire Of Human Adipocyte Subtypes Develops From Transcriptionally Distinct Mesenchymal Progenitor Cells, So Yun Min, Anand Desai, Zinger Yang, Agastya Sharma, Tiffany Desouza, Ryan Genga, Alper Kucukural, Lawrence M. Lifshitz, Soren Nielsen, Camilla Scheele, Rene Maehr, Manuel Garber, Silvia Corvera

Open Access Articles

Single-cell sequencing technologies have revealed an unexpectedly broad repertoire of cells required to mediate complex functions in multicellular organisms. Despite the multiple roles of adipose tissue in maintaining systemic metabolic homeostasis, adipocytes are thought to be largely homogenous with only 2 major subtypes recognized in humans so far. Here we report the existence and characteristics of 4 distinct human adipocyte subtypes, and of their respective mesenchymal progenitors. The phenotypes of these distinct adipocyte subtypes are differentially associated with key adipose tissue functions, including thermogenesis, lipid storage, and adipokine secretion. The transcriptomic signature of "brite/beige" thermogenic adipocytes reveals mechanisms for ...


Role Of A 19s Proteasome Subunit- Psmd10(Gankyrin) In Neurogenesis Of Human Neuronal Progenitor Cells, Indrajit Sahu, Padma P. Nanaware, Minal Mane, Saim Wasi Mulla, Soumen Roy, Prasanna Venkatraman Aug 2019

Role Of A 19s Proteasome Subunit- Psmd10(Gankyrin) In Neurogenesis Of Human Neuronal Progenitor Cells, Indrajit Sahu, Padma P. Nanaware, Minal Mane, Saim Wasi Mulla, Soumen Roy, Prasanna Venkatraman

Open Access Articles

PSMD10(Gankyrin), a proteasome assembly chaperone, is a widely known oncoprotein which aspects many hall mark properties of cancer. However, except proteasome assembly chaperon function its role in normal cell function remains unknown. To address this issue, we induced PSMD10(Gankyrin) overexpression in HEK293 cells and the resultant large-scale changes in gene expression profile were analyzed. We constituted networks from microarray data of these differentially expressed genes and carried out extensive topological analyses. The overrecurring yet consistent theme that appeared throughout analysis using varied network metrics is that all genes and interactions identified as important would be involved in neurogenesis ...


Modeling Of Cisplatin-Induced Signaling Dynamics In Triple-Negative Breast Cancer Cells Reveals Mediators Of Sensitivity, Anne Margriet Heijink, Marieke Everts, Megan E. Honeywell, Ryan Richards, Yannick P. Kok, Elisabeth G. E. De Vries, Michael J. Lee, Marcel A T M Van Vugt Aug 2019

Modeling Of Cisplatin-Induced Signaling Dynamics In Triple-Negative Breast Cancer Cells Reveals Mediators Of Sensitivity, Anne Margriet Heijink, Marieke Everts, Megan E. Honeywell, Ryan Richards, Yannick P. Kok, Elisabeth G. E. De Vries, Michael J. Lee, Marcel A T M Van Vugt

Open Access Articles

Triple-negative breast cancers (TNBCs) display great diversity in cisplatin sensitivity that cannot be explained solely by cancer-associated DNA repair defects. Differential activation of the DNA damage response (DDR) to cisplatin has been proposed to underlie the observed differential sensitivity, but it has not been investigated systematically. Systems-level analysis-using quantitative time-resolved signaling data and phenotypic responses, in combination with mathematical modeling-identifies that the activation status of cell-cycle checkpoints determines cisplatin sensitivity in TNBC cell lines. Specifically, inactivation of the cell-cycle checkpoint regulator MK2 or G3BP2 sensitizes cisplatin-resistant TNBC cell lines to cisplatin. Dynamic signaling data of five cell cycle-related signals predicts ...


Promotion Of Adipogenesis By Jmjd6 Requires The At Hook-Like Domain And Is Independent Of Its Catalytic Function, Pablo Reyes-Gutierrez, Jake W. Carrasquillo-Rodriguez, Anthony N. Imbalzano Aug 2019

Promotion Of Adipogenesis By Jmjd6 Requires The At Hook-Like Domain And Is Independent Of Its Catalytic Function, Pablo Reyes-Gutierrez, Jake W. Carrasquillo-Rodriguez, Anthony N. Imbalzano

Open Access Articles

JMJD6 is a member of the Jumonji C domain containing enzymes that demethylate and/or hydroxylate substrate proteins. It is a multi-functional protein that has been implicated in disparate aspects of transcriptional and post-transcriptional control of gene expression, including but not limited to enhancer and promoter binding, release of paused RNA polymerase II, control of splicing, and interaction with the translation machinery. JMJD6 contributes to multiple aspects of animal development, including adipogenesis modeled in culture. We mutated proposed or characterized domains in the JMJD6 protein to better understand the requirement for JMJD6 in adipogenic differentiation. Mutation of JMJD6 amino acids ...


Multimodal Quantitative Imaging Of Brain Cancer In Cultured Cells, Xin Feng, Alona Muzikansky, Alonzo H. Ross, Michael R. Hamblin, Peter R. Jermain, Anna N. Yaroslavsky Jul 2019

Multimodal Quantitative Imaging Of Brain Cancer In Cultured Cells, Xin Feng, Alona Muzikansky, Alonzo H. Ross, Michael R. Hamblin, Peter R. Jermain, Anna N. Yaroslavsky

Open Access Articles

Fluorescence emission, polarization and subcellular localization of methylene blue (MB) were studied in four cancerous and two normal human brain cell lines. Fluorescence emission and polarization images were acquired and analyzed. The co-localization of MB with mitochondria, lysosomes and nuclei of the cells was evaluated. Glioblastoma cells exhibited significantly higher MB fluorescence polarization compared to normal astrocytes. Preferential accumulation of MB in mitochondria of glioblastoma cells may explain higher fluorescence polarization values in cancer cells as compared to normal. These findings may lead to the development of a quantitative method for the detection of brain cancer in single cells.


Calcineurin Broadly Regulates The Initiation Of Skeletal Muscle-Specific Gene Expression By Binding Target Promoters And Facilitating The Interaction Of The Swi/Snf Chromatin Remodeling Enzyme, Hanna Witwicka, Jumpei Nogami, Sabriya A. Syed, Kazumitsu Maehara, Teresita Padilla-Benavides, Yasuyuki Ohkawa, Anthony N. Imbalzano Jul 2019

Calcineurin Broadly Regulates The Initiation Of Skeletal Muscle-Specific Gene Expression By Binding Target Promoters And Facilitating The Interaction Of The Swi/Snf Chromatin Remodeling Enzyme, Hanna Witwicka, Jumpei Nogami, Sabriya A. Syed, Kazumitsu Maehara, Teresita Padilla-Benavides, Yasuyuki Ohkawa, Anthony N. Imbalzano

Open Access Articles

Calcineurin (Cn) is a calcium-activated serine/threonine protein phosphatase that is broadly implicated in diverse cellular processes, including the regulation of gene expression. During skeletal muscle differentiation, Cn activates the NFAT transcription factor but also promotes differentiation by counteracting the negative influences of protein kinase C beta (PKCbeta) via dephosphorylation and activation of BRG1, an enzymatic subunit of the mammalian SWI/SNF ATP-dependent chromatin remodeling enzyme. Here we identified four major temporal patterns of Cn-dependent gene expression in differentiating myoblasts and determined that Cn is broadly required for the activation of the myogenic gene expression program. Mechanistically, Cn promotes gene ...


F-Box Protein Fbxo16 Functions As A Tumor Suppressor By Attenuating Nuclear Beta-Catenin Function, Debasish Paul, Sehbanul Islam, Rajesh Kumar. Manne, U. S. Dinesh, Sunil K. Malonia, Biswanath Maity, Ramanamurthy Boppana, Srikanth Rapole, Praveen Kumar Shetty, Manas Kumar Santra Jul 2019

F-Box Protein Fbxo16 Functions As A Tumor Suppressor By Attenuating Nuclear Beta-Catenin Function, Debasish Paul, Sehbanul Islam, Rajesh Kumar. Manne, U. S. Dinesh, Sunil K. Malonia, Biswanath Maity, Ramanamurthy Boppana, Srikanth Rapole, Praveen Kumar Shetty, Manas Kumar Santra

Open Access Articles

Aberrant activation of beta-catenin has been implicated in a variety of human diseases, including cancer. In spite of significant progress, the regulation of active Wnt/beta-catenin-signaling pathways is still poorly understood. In this study, we show that F-box protein 16 (FBXO16) is a putative tumor suppressor. It is a component of the SCF (SKP1-Cullin1-F-box protein) complex, which targets the nuclear beta-catenin protein to facilitate proteasomal degradation through the 26S proteasome. FBXO16 interacts physically with the C-terminal domain of beta-catenin and promotes its lysine 48-linked polyubiquitination. In addition, it inhibits epithelial-to-mesenchymal transition (EMT) by attenuating the level of beta-catenin. Therefore, depletion ...


Tethering Of Vesicles To The Golgi By Gmap210 Controls Lat Delivery To The Immune Synapse, Andres Ernesto Zucchetti, Laurence Bataille, Jean-Marie Carpier, Stephanie Dogniaux, Mabel San Roman-Jouve, Mathieu Maurin, Michael W. Stuck, Rosa M. Rios, Cosima T. Baldari, Gregory J. Pazour, Claire Hivroz Jun 2019

Tethering Of Vesicles To The Golgi By Gmap210 Controls Lat Delivery To The Immune Synapse, Andres Ernesto Zucchetti, Laurence Bataille, Jean-Marie Carpier, Stephanie Dogniaux, Mabel San Roman-Jouve, Mathieu Maurin, Michael W. Stuck, Rosa M. Rios, Cosima T. Baldari, Gregory J. Pazour, Claire Hivroz

Open Access Articles

The T cell immune synapse is a site of intense vesicular trafficking. Here we show that the golgin GMAP210, known to capture vesicles and organize membrane traffic at the Golgi, is involved in the vesicular transport of LAT to the immune synapse. Upon activation, more GMAP210 interact with LAT-containing vesicles and go together with LAT to the immune synapse. Regulating LAT recruitment and LAT-dependent signaling, GMAP210 controls T cell activation. Using a rerouting and capture assay, we show that GMAP210 captures VAMP7-decorated vesicles. Overexpressing different domains of GMAP210, we also show that GMAP210 allows their specific delivery to the immune ...


Somatic Molecular Analysis Augments Cytologic Evaluation Of Pancreatic Cyst Fluids As A Diagnostic Tool, Ali Sakhdari, Parnian Ahmadi Moghaddam, Chi Young Ok, Otto Walter, Keith Tomaszewicz, Mandi-Lee Caporelli, Xiuling Meng, Jennifer Lafemina, Giles F. Whalen, Edward Belkin, Jaroslav Zivny, Wahid Y. Wassef, Bruce A. Woda, Lloyd Hutchinson, Ediz F. Cosar Jun 2019

Somatic Molecular Analysis Augments Cytologic Evaluation Of Pancreatic Cyst Fluids As A Diagnostic Tool, Ali Sakhdari, Parnian Ahmadi Moghaddam, Chi Young Ok, Otto Walter, Keith Tomaszewicz, Mandi-Lee Caporelli, Xiuling Meng, Jennifer Lafemina, Giles F. Whalen, Edward Belkin, Jaroslav Zivny, Wahid Y. Wassef, Bruce A. Woda, Lloyd Hutchinson, Ediz F. Cosar

Open Access Articles

Objective: Better tools are needed for early diagnosis and classification of pancreatic cystic lesions (PCL) to trigger intervention before neoplastic precursor lesions progress to adenocarcinoma. We evaluated the capacity of molecular analysis to improve the accuracy of cytologic diagnosis for PCL with an emphasis on non-diagnostic/negative specimens.

Design: In a span of 7 years, at a tertiary care hospital, 318 PCL endoscopic ultrasound-guided fine needle aspirations (EUS-FNA) were evaluated by cytologic examination and molecular analysis. Mucinous PCL were identified based on a clinical algorithm and 46 surgical resections were used to verify this approach. The mutation allele frequency (MAF ...


Extracellular-Signal Regulated Kinase: A Central Molecule Driving Epithelial-Mesenchymal Transition In Cancer, Monserrat Olea-Flores, Miriam Daniela Zuniga-Eulogio, Miguel Angel Mendoza-Catalan, Hugo Alberto Rodriguez-Ruiz, Eduardo Castaneda-Saucedo, Carlos Ortuno-Pineda, Teresita Padilla-Benavides, Napoleon Navarro-Tito Jun 2019

Extracellular-Signal Regulated Kinase: A Central Molecule Driving Epithelial-Mesenchymal Transition In Cancer, Monserrat Olea-Flores, Miriam Daniela Zuniga-Eulogio, Miguel Angel Mendoza-Catalan, Hugo Alberto Rodriguez-Ruiz, Eduardo Castaneda-Saucedo, Carlos Ortuno-Pineda, Teresita Padilla-Benavides, Napoleon Navarro-Tito

Open Access Articles

Epithelial-mesenchymal transition (EMT) is a reversible cellular process, characterized by changes in gene expression and activation of proteins, favoring the trans-differentiation of the epithelial phenotype to a mesenchymal phenotype. This process increases cell migration and invasion of tumor cells, progression of the cell cycle, and resistance to apoptosis and chemotherapy, all of which support tumor progression. One of the signaling pathways involved in tumor progression is the MAPK pathway. Within this family, the ERK subfamily of proteins is known for its contributions to EMT. The ERK subfamily is divided into typical (ERK 1/2/5), and atypical (ERK 3/4 ...


Adipocyte Acly Facilitates Dietary Carbohydrate Handling To Maintain Metabolic Homeostasis In Females, Sully Fernandez, John M. Viola, Annmarie Torres, Martina Wallace, Sophie Trefely, Steven Zhao, Hayley C. Affronti, Jivani M. Gengatharan, David A. Guertin, Nathaniel W. Snyder, Christian M. Metallo, Kathryn E. Wellen May 2019

Adipocyte Acly Facilitates Dietary Carbohydrate Handling To Maintain Metabolic Homeostasis In Females, Sully Fernandez, John M. Viola, Annmarie Torres, Martina Wallace, Sophie Trefely, Steven Zhao, Hayley C. Affronti, Jivani M. Gengatharan, David A. Guertin, Nathaniel W. Snyder, Christian M. Metallo, Kathryn E. Wellen

Open Access Articles

Sugars and refined carbohydrates are major components of the modern diet. ATP-citrate lyase (ACLY) is upregulated in adipocytes in response to carbohydrate consumption and generates acetyl-coenzyme A (CoA) for both lipid synthesis and acetylation reactions. Here, we investigate the role of ACLY in the metabolic and transcriptional responses to carbohydrates in adipocytes and unexpectedly uncover a sexually dimorphic function in maintaining systemic metabolic homeostasis. When fed a high-sucrose diet, Acly(FAT-/-) females exhibit a lipodystrophy-like phenotype, with minimal fat accumulation, insulin resistance, and hepatic lipid accumulation, whereas Acly(FAT-/-) males have only mild metabolic phenotypes. We find that ACLY is ...


Serum Deprivation Of Mesenchymal Stem Cells Improves Exosome Activity And Alters Lipid And Protein Composition, Reka A. Haraszti, Rachael Miller, Michelle L. Dubuke, Andrew H. Coles, Marie C. Didiot, Dimas Echeverria, Matteo Stoppato, Yves Y. Sere, John D. Leszyk, Julia F. Alterman, Bruno M. D. C. Godinho, Matthew R. Hassler, Rachel Wollacott, Yan Wang, Scott A. Shaffer, Neil Aronin, Anastasia Khvorova May 2019

Serum Deprivation Of Mesenchymal Stem Cells Improves Exosome Activity And Alters Lipid And Protein Composition, Reka A. Haraszti, Rachael Miller, Michelle L. Dubuke, Andrew H. Coles, Marie C. Didiot, Dimas Echeverria, Matteo Stoppato, Yves Y. Sere, John D. Leszyk, Julia F. Alterman, Bruno M. D. C. Godinho, Matthew R. Hassler, Rachel Wollacott, Yan Wang, Scott A. Shaffer, Neil Aronin, Anastasia Khvorova

Open Access Articles

Exosomes can serve as delivery vehicles for advanced therapeutics. The components necessary and sufficient to support exosomal delivery have not been established. Here we connect biochemical composition and activity of exosomes to optimize exosome-mediated delivery of small interfering RNAs (siRNAs). This information is used to create effective artificial exosomes. We show that serum-deprived mesenchymal stem cells produce exosomes up to 22-fold more effective at delivering siRNAs to neurons than exosomes derived from control cells. Proteinase treatment of exosomes stops siRNA transfer, indicating that surface proteins on exosomes are involved in trafficking. Proteomic and lipidomic analyses show that exosomes derived in ...


Jnk(1/2) Represses Lkb(1)-Deficiency-Induced Lung Squamous Cell Carcinoma Progression, Jian Liu, Tianyuan Wang, Chad J. Creighton, San-Pin Wu, Madhumita Ray, Kyathanahalli S. Janardhan, Cynthia J. Willson, Sung-Nam Cho, Patricia D. Castro, Michael M. Ittmann, Jian-Liang Li, Roger J. Davis, Francesco J. Demayo May 2019

Jnk(1/2) Represses Lkb(1)-Deficiency-Induced Lung Squamous Cell Carcinoma Progression, Jian Liu, Tianyuan Wang, Chad J. Creighton, San-Pin Wu, Madhumita Ray, Kyathanahalli S. Janardhan, Cynthia J. Willson, Sung-Nam Cho, Patricia D. Castro, Michael M. Ittmann, Jian-Liang Li, Roger J. Davis, Francesco J. Demayo

Open Access Articles

Mechanisms of lung squamous cell carcinoma (LSCC) development are poorly understood. Here, we report that JNK1/2 activities attenuate Lkb1-deficiency-driven LSCC initiation and progression through repressing DeltaNp63 signaling. In vivo Lkb1 ablation alone is sufficient to induce LSCC development by reducing MKK7 levels and JNK1/2 activities, independent of the AMPKalpha and mTOR pathways. JNK1/2 activities is positively regulated by MKK7 during LSCC development. Pharmaceutically elevated JNK1/2 activities abates Lkb1 dependent LSCC formation while compound mutations of Jnk1/2 and Lkb1 further accelerate LSCC progression. JNK1/2 is inactivated in a substantial proportion of human LSCC and JNK1 ...


Ouabain Enhances Cell-Cell Adhesion Mediated By Beta1 Subunits Of The Na(+),K(+)-Atpase In Cho Fibroblasts, Claudia Andrea Vilchis-Nestor, Maria Luisa Roldan, Angelina Leonardi, Juan G. Navea, Teresita Padilla-Benavides, Liora Shoshani Apr 2019

Ouabain Enhances Cell-Cell Adhesion Mediated By Beta1 Subunits Of The Na(+),K(+)-Atpase In Cho Fibroblasts, Claudia Andrea Vilchis-Nestor, Maria Luisa Roldan, Angelina Leonardi, Juan G. Navea, Teresita Padilla-Benavides, Liora Shoshani

Open Access Articles

Adhesion is a crucial characteristic of epithelial cells to form barriers to pathogens and toxic substances from the environment. Epithelial cells attach to each other using intercellular junctions on the lateral membrane, including tight and adherent junctions, as well as the Na(+),K(+)-ATPase. Our group has shown that non-adherent chinese hamster ovary (CHO) cells transfected with the canine beta1 subunit become adhesive, and those homotypic interactions amongst beta1 subunits of the Na(+),K(+)-ATPase occur between neighboring epithelial cells. Ouabain, a cardiotonic steroid, binds to the alpha subunit of the Na(+),K(+)-ATPase, inhibits the pump activity and induces ...


Exploiting Unique Biological Features Of Leukemia Stem Cells For Therapeutic Benefit, Haojian Zhang, Shaoguang Li Apr 2019

Exploiting Unique Biological Features Of Leukemia Stem Cells For Therapeutic Benefit, Haojian Zhang, Shaoguang Li

Open Access Articles

Cancer stem cells play a critical role in disease initiation and insensitivity to chemotherapy in numerous hematologic malignancies and some solid tumors, and these stem cells need to be eradicated to achieve a cure. Key to successful targeting of cancer stem cells is to identify and functionally test critical target genes and to fully understand their associated molecular network in these stem cells. Human chronic myeloid leukemia (CML) is well accepted as one of the typical types of hematopoietic malignancies that are derived from leukemia stem cells (LSCs), serving as an excellent model disease for understanding the biology of LSCs ...


Single-Cell Rna-Sequencing-Based Crispri Screening Resolves Molecular Drivers Of Early Human Endoderm Development, Ryan M. Genga, Eric M. Kernfeld, Krishna M. Parsi, Teagan J. Parsons, Michael J. Ziller, Rene Maehr Apr 2019

Single-Cell Rna-Sequencing-Based Crispri Screening Resolves Molecular Drivers Of Early Human Endoderm Development, Ryan M. Genga, Eric M. Kernfeld, Krishna M. Parsi, Teagan J. Parsons, Michael J. Ziller, Rene Maehr

Open Access Articles

Studies in vertebrates have outlined conserved molecular control of definitive endoderm (END) development. However, recent work also shows that key molecular aspects of human END regulation differ even from rodents. Differentiation of human embryonic stem cells (ESCs) to END offers a tractable system to study the molecular basis of normal and defective human-specific END development. Here, we interrogated dynamics in chromatin accessibility during differentiation of ESCs to END, predicting DNA-binding proteins that may drive this cell fate transition. We then combined single-cell RNA-seq with parallel CRISPR perturbations to comprehensively define the loss-of-function phenotype of those factors in END development. Following ...


The Erk Mapk Pathway Is Essential For Skeletal Development And Homeostasis, Jung-Min Kim, Yeon-Suk Yang, Kwang Hwan Park, Hwanhee Oh, Matthew B. Greenblatt, Jae-Hyuck Shim Apr 2019

The Erk Mapk Pathway Is Essential For Skeletal Development And Homeostasis, Jung-Min Kim, Yeon-Suk Yang, Kwang Hwan Park, Hwanhee Oh, Matthew B. Greenblatt, Jae-Hyuck Shim

Open Access Articles

Mitogen-activated protein kinases (MAPKs) are a family of protein kinases that function as key signal transducers of a wide spectrum of extracellular stimuli, including growth factors and pro-inflammatory cytokines. Dysregulation of the extracellular signal-regulated kinase (ERK) MAPK pathway is associated with human skeletal abnormalities including Noonan syndrome, neurofibromatosis type 1, and cardiofaciocutaneous syndrome. Here, we demonstrate that ERK activation in osteoprogenitors is required for bone formation during skeletal development and homeostasis. Deletion of Mek1 and Mek2, kinases upstream of ERK MAPK, in osteoprogenitors (Mek1(Osx)Mek2(-/-)), resulted in severe osteopenia and cleidocranial dysplasia (CCD), similar to that seen in humans ...


The Er-Localized Protein Dfcp1 Modulates Er-Lipid Droplet Contact Formation, Dongfang Li, Yan G. Zhao, Di Li, Hongyu Zhao, Jie Huang, Guangyan Miao, Du Feng, Pingsheng Liu, Dong Li, Hong Zhang Apr 2019

The Er-Localized Protein Dfcp1 Modulates Er-Lipid Droplet Contact Formation, Dongfang Li, Yan G. Zhao, Di Li, Hongyu Zhao, Jie Huang, Guangyan Miao, Du Feng, Pingsheng Liu, Dong Li, Hong Zhang

Open Access Articles

Very little is known about the spatiotemporal generation of lipid droplets (LDs) from the endoplasmic reticulum (ER) and the factors that mediate ER-LD contacts for LD growth. Using super-resolution grazing incidence structured illumination microscopy (GI-SIM) live-cell imaging, we reveal that upon LD induction, the ER-localized protein DFCP1 redistributes to nascent puncta on the ER, whose formation depends on triglyceride synthesis. These structures move along the ER and fuse to form expanding LDs. Fusion and expansion of DFCP1-labeled nascent structures is controlled by BSCL2. BSCL2 depletion causes accumulation of nascent DFCP1 structures. DFCP1 overexpression increases LD size and enhances ER-LD contacts ...


Genome-Scale Crispr Screens Identify Human Pluripotency-Specific Genes, Robert J. Ihry, Zinger Yang, Ajamete Kaykas Apr 2019

Genome-Scale Crispr Screens Identify Human Pluripotency-Specific Genes, Robert J. Ihry, Zinger Yang, Ajamete Kaykas

Open Access Articles

Human pluripotent stem cells (hPSCs) generate a variety of disease-relevant cells that can be used to improve the translation of preclinical research. Despite the potential of hPSCs, their use for genetic screening has been limited by technical challenges. We developed a scalable and renewable Cas9 and sgRNA-hPSC library in which loss-of-function mutations can be induced at will. Our inducible mutant hPSC library can be used for multiple genome-wide CRISPR screens in a variety of hPSC-induced cell types. As proof of concept, we performed three screens for regulators of properties fundamental to hPSCs: their ability to self-renew and/or survive (fitness ...


Transfer Rna Genes Affect Chromosome Structure And Function Via Local Effects, Omar Hamdani, Tsung-Han S. Hsieh, Oliver J. Rando, Rohinton T. Kamakaka Apr 2019

Transfer Rna Genes Affect Chromosome Structure And Function Via Local Effects, Omar Hamdani, Tsung-Han S. Hsieh, Oliver J. Rando, Rohinton T. Kamakaka

Open Access Articles

The genome is packaged and organized in an ordered, non-random manner and specific chromatin segments contact nuclear substructures to mediate this organization. Transfer RNA genes (tDNAs) are binding sites for transcription factors and architectural proteins and are thought to play an important role in the organization of the genome. In this study, we investigate the role of tDNAs in genomic organization and chromosome function by editing a chromosome so that it lacks any tDNAs. Surprisingly our analyses of this tDNA-less chromosome show that loss of tDNAs does not grossly affect chromatin architecture or chromosome tethering and mobility. However, loss of ...


Entosis Controls A Developmental Cell Clearance In C. Elegans, Yongchan Lee, Jens C. Hamann, Mark Pellegrino, Joanne Durgan, Marie-Charlotte Domart, Lucy M. Collinson, Cole M. Haynes, Oliver Florey, Michael Overholtzer Mar 2019

Entosis Controls A Developmental Cell Clearance In C. Elegans, Yongchan Lee, Jens C. Hamann, Mark Pellegrino, Joanne Durgan, Marie-Charlotte Domart, Lucy M. Collinson, Cole M. Haynes, Oliver Florey, Michael Overholtzer

Open Access Articles

Metazoan cell death mechanisms are diverse and include numerous non-apoptotic programs. One program called entosis involves the invasion of live cells into their neighbors and is known to occur in cancers. Here, we identify a developmental function for entosis: to clear the male-specific linker cell in C. elegans. The linker cell leads migration to shape the gonad and is removed to facilitate fusion of the gonad to the cloaca. We find that the linker cell is cleared in a manner involving cell-cell adhesions and cell-autonomous control of uptake through linker cell actin. Linker cell entosis generates a lobe structure that ...


Adenosine Triphosphate Is Co-Secreted With Glucagon-Like Peptide-1 To Modulate Intestinal Enterocytes And Afferent Neurons, Van B. Lu, Juraj Rievaj, Elisabeth A. O'Flaherty, Christopher A. Smith, Ramona Pais, Luke A. Pattison, Gwen Tolhurst, Andrew B. Leiter, David C. Bulmer, Fiona M. Gribble, Frank Reimann Mar 2019

Adenosine Triphosphate Is Co-Secreted With Glucagon-Like Peptide-1 To Modulate Intestinal Enterocytes And Afferent Neurons, Van B. Lu, Juraj Rievaj, Elisabeth A. O'Flaherty, Christopher A. Smith, Ramona Pais, Luke A. Pattison, Gwen Tolhurst, Andrew B. Leiter, David C. Bulmer, Fiona M. Gribble, Frank Reimann

Open Access Articles

Enteroendocrine cells are specialised sensory cells located in the intestinal epithelium and generate signals in response to food ingestion. Whilst traditionally considered hormone-producing cells, there is evidence that they also initiate activity in the afferent vagus nerve and thereby signal directly to the brainstem. We investigate whether enteroendocrine L-cells, well known for their production of the incretin hormone glucagon-like peptide-1 (GLP-1), also release other neuro-transmitters/modulators. We demonstrate regulated ATP release by ATP measurements in cell supernatants and by using sniffer patches that generate electrical currents upon ATP exposure. Employing purinergic receptor antagonists, we demonstrate that evoked ATP release from ...


Receptor Interacting Protein Kinase 3 (Rip3) Regulates Ipscs Generation Through Modulating Cell Cycle Progression Genes, Ahmad Al-Moujahed, Bo Tian, Nikolaos E. Efstathiou, Eleni K. Konstantinou, Mien Hoang, Haijiang Lin, Joan W. Miller, Demetrios G. Vavvas Mar 2019

Receptor Interacting Protein Kinase 3 (Rip3) Regulates Ipscs Generation Through Modulating Cell Cycle Progression Genes, Ahmad Al-Moujahed, Bo Tian, Nikolaos E. Efstathiou, Eleni K. Konstantinou, Mien Hoang, Haijiang Lin, Joan W. Miller, Demetrios G. Vavvas

Open Access Articles

The molecular mechanisms involved in induced pluripotent stem cells (iPSCs) generation are poorly understood. The cell death machinery of apoptosis-inducing caspases have been shown to facilitate the process of iPSCs reprogramming. However, the effect of other cell death processes, such as programmed necrosis (necroptosis), on iPSCs induction has not been studied. In this study, we investigated the role of receptor-interacting protein kinase 3 (RIP3), an essential regulator of necroptosis, in reprogramming mouse embryonic fibroblast cells (MEFs) into iPSCs. RIP3 was found to be upregulated in iPSCs compared to MEFs. Deletion of RIP3 dramatically suppressed the reprogramming of iPSCs (~82%). RNA-seq ...


Viral Infection Or Ifn-Alpha Alters Mitotic Spindle Orientation By Modulating Pericentrin Levels, William M. Mcdougall, Jill Perreira, Hui-Fang Hung, Anastassiia Vertii, E. Xiaofei, Wendy Zimmerman, Timothy F. Kowalik, Stephen J. Doxsey, Abraham L. Brass Feb 2019

Viral Infection Or Ifn-Alpha Alters Mitotic Spindle Orientation By Modulating Pericentrin Levels, William M. Mcdougall, Jill Perreira, Hui-Fang Hung, Anastassiia Vertii, E. Xiaofei, Wendy Zimmerman, Timothy F. Kowalik, Stephen J. Doxsey, Abraham L. Brass

Open Access Articles

Congenital microcephaly occurs in utero during Zika virus (ZIKV) infection. The single-gene disorder, Majewski osteodysplastic primordial dwarfism type II (MOPDII), also leads to microcephaly and is concomitant with a decrease in the centrosomal protein, pericentrin (PCNT). This protein is a known contributor of mitotic spindle misorientation and ultimately, microcephaly. Similar to MOPDII, either viral infection or interferon (IFN)-alpha exposure reduced PCNT levels at the mitotic spindle poles. We unexpectedly found that infection of cells with any one of a diverse set of viruses, such as ZIKV, dengue virus, cytomegalovirus, influenza A virus, or hepatitis B virus, or treatment of ...


Huntingtin Associates With The Actin Cytoskeleton And Alpha-Actinin Isoforms To Influence Stimulus Dependent Morphology Changes, Adelaide Tousley, Maria Iuliano, Elizabeth Weisman, Ellen Sapp, Heather Richardson, Petr Vodicka, Jonathan Alexander, Neil Aronin, Marian Difiglia, Kimberly B. Kegel-Gleason Feb 2019

Huntingtin Associates With The Actin Cytoskeleton And Alpha-Actinin Isoforms To Influence Stimulus Dependent Morphology Changes, Adelaide Tousley, Maria Iuliano, Elizabeth Weisman, Ellen Sapp, Heather Richardson, Petr Vodicka, Jonathan Alexander, Neil Aronin, Marian Difiglia, Kimberly B. Kegel-Gleason

Open Access Articles

One response of cells to growth factor stimulus involves changes in morphology driven by the actin cytoskeleton and actin associated proteins which regulate functions such as cell adhesion, motility and in neurons, synaptic plasticity. Previous studies suggest that Huntingtin may be involved in regulating morphology however, there has been limited evidence linking endogenous Huntingtin localization or function with cytoplasmic actin in cells. We found that depletion of Huntingtin in human fibroblasts reduced adhesion and altered morphology and these phenotypes were made worse with growth factor stimulation, whereas the presence of the Huntington's Disease mutation inhibited growth factor induced changes ...


Hypomorphic Mutations Of Trip11 Cause Odontochondrodysplasia, Anika Wehrle, John A. Follit, Gregory J. Pazour, Andrea Superti-Furga, Martin Lowe, Ekkehart Lausch Feb 2019

Hypomorphic Mutations Of Trip11 Cause Odontochondrodysplasia, Anika Wehrle, John A. Follit, Gregory J. Pazour, Andrea Superti-Furga, Martin Lowe, Ekkehart Lausch

Open Access Articles

Odontochondrodysplasia (ODCD) is an unresolved genetic disorder of skeletal and dental development. Here, we show that ODCD is caused by hypomorphic TRIP11 mutations, and we identify ODCD as the nonlethal counterpart to achondrogenesis 1A (ACG1A), the known null phenotype in humans. TRIP11 encodes Golgi-associated microtubule-binding protein 210 (GMAP-210), an essential tether protein of the Golgi apparatus that physically interacts with intraflagellar transport 20 (IFT20), a component of the ciliary intraflagellar transport complex B. This association and extraskeletal disease manifestations in ODCD point to a cilium-dependent pathogenesis. However, our functional studies in patient-derived primary cells clearly support a Golgi-based disease mechanism ...


Vegf/Neuropilin Signaling In Cancer Stem Cells, Arthur M. Mercurio Jan 2019

Vegf/Neuropilin Signaling In Cancer Stem Cells, Arthur M. Mercurio

Open Access Articles

The function of vascular endothelial growth factor (VEGF) in cancer extends beyond angiogenesis and vascular permeability. Specifically, VEGF-mediated signaling occurs in tumor cells and this signaling contributes to key aspects of tumorigenesis including the self-renewal and survival of cancer stem cells (CSCs). In addition to VEGF receptor tyrosine kinases, the neuropilins (NRPs) are critical for mediating the effects of VEGF on CSCs, primarily because of their ability to impact the function of growth factor receptors and integrins. VEGF/NRP signaling can regulate the expression and function of key molecules that have been implicated in CSC function including Rho family guanosine ...