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Apoptosis

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Articles 31 - 60 of 69

Full-Text Articles in Cell Biology

Ampa-Kainate Receptor Inhibition Promotes Neurologic Recovery In Premature Rabbits With Intraventricular Hemorrhage, Preeti Dohare, Muhammad T. Zia, Ehsan Ahmed, Asad Ahmed, Vivek Yadala, Praveen Ballabh Mar 2016

Ampa-Kainate Receptor Inhibition Promotes Neurologic Recovery In Premature Rabbits With Intraventricular Hemorrhage, Preeti Dohare, Muhammad T. Zia, Ehsan Ahmed, Asad Ahmed, Vivek Yadala, Praveen Ballabh

NYMC Faculty Publications

Intraventricular hemorrhage (IVH) in preterm infants leads to cerebral inflammation, reduced myelination of the white matter, and neurological deficits. No therapeutic strategy exists against the IVH-induced white matter injury. AMPA-kainate receptor induced excitotoxicity contributes to oligodendrocyte precursor cell (OPC) damage and hypomyelination in both neonatal and adult models of brain injury. Here, we hypothesized that IVH damages white matter via AMPA receptor activation, and that AMPA-kainate receptor inhibition suppresses inflammation and restores OPC maturation, myelination, and neurologic recovery in preterm newborns with IVH. We tested these hypotheses in a rabbit model of glycerol-induced IVH and evaluated the expression of AMPA ...


Transcriptional Activation Of Follistatin By Nrf2 Protects Pulmonary Epithelial Cells Against Silica Nanoparticle-Induced Oxidative Stress, Chen Lin, Xinyuan Zhao, Desen Sun, Lingda Zhang, Wenpan Fang, Tingjia Zhu, Qiang Wang, Botao Liu, Saisai Wei, Guangdi Chen, Zhengping Xu, Xiangwei Gao Feb 2016

Transcriptional Activation Of Follistatin By Nrf2 Protects Pulmonary Epithelial Cells Against Silica Nanoparticle-Induced Oxidative Stress, Chen Lin, Xinyuan Zhao, Desen Sun, Lingda Zhang, Wenpan Fang, Tingjia Zhu, Qiang Wang, Botao Liu, Saisai Wei, Guangdi Chen, Zhengping Xu, Xiangwei Gao

Open Access Articles

Silica nanoparticles (SiO2 NPs) cause oxidative stress in respiratory system. Meanwhile, human cells launch adaptive responses to overcome SiO2 NP toxicity. However, besides a few examples, the regulation of SiO2 NP-responsive proteins and their functions in SiO2 NP response remain largely unknown. In this study, we demonstrated that SiO2 NP induced the expression of follistatin (FST), a stress responsive gene, in mouse lung tissue as well as in human lung epithelial cells (A549). The levels of Ac-H3(K9/18) and H3K4me2, two active gene markers, at FST promoter region were significantly increased during SiO2 NP treatment. The induction of FST ...


Mir494 Reduces Renal Cancer Cell Survival Coinciding With Increased Lipid Droplets And Mitochondrial Changes, Punashi Dutta, Edward Haller, Arielle Sharp, Meera Nanjundan Jan 2016

Mir494 Reduces Renal Cancer Cell Survival Coinciding With Increased Lipid Droplets And Mitochondrial Changes, Punashi Dutta, Edward Haller, Arielle Sharp, Meera Nanjundan

Cell Biology, Microbiology, and Molecular Biology Faculty Publications

Background: miRNAs can regulate cellular survival in various cancer cell types. Recent evidence implicates the formation of lipid droplets as a hallmark event during apoptotic cell death response. It is presently unknown whether MIR494, located at 14q32 which is deleted in renal cancers, reduces cell survival in renal cancer cells and if this process is accompanied by changes in the number of lipid droplets.

Methods: 769-P renal carcinoma cells were utilized for this study. Control or MIR494 mimic was expressed in these cells following which cell viability (via crystal violet) and apoptotic cell numbers (via Annexin V/PI staining) were ...


Direct Regulation Of Apoptosis By Linear Ubiqutin Chain Assembly Complex (Lubac) And Feedback Regulation Of Lubac Function By Caspases, Donghyun Joo Aug 2015

Direct Regulation Of Apoptosis By Linear Ubiqutin Chain Assembly Complex (Lubac) And Feedback Regulation Of Lubac Function By Caspases, Donghyun Joo

UT GSBS Dissertations and Theses (Open Access)

Tumor Necrosis Factor-alpha (TNF-α) is a cytokine that plays a role in various cellular processes such as proliferation, differentiation (mainly through NF-κB signaling) and death (via apoptosis signaling). Recently, linear ubiquitination by LUBAC (linear ubiquitin chain assembly complex) was reported to have a regulatory function in TNF-α mediated NF-κB activation. Although LUBAC is suggested to control not only NF-kB signaling but also the apoptosis pathway, the precise mechanism of apoptosis regulation remains unknown. Moreover, NF-κB and apoptosis pathways have opposed but fundamental functions for various cellular processes. Although these two pathways actively interplay to balance the death and survival, the ...


The Bbc3 Antisense Intragenic Transcript, Bait, Contributes To Puma Expression By A P53-Autonomous Mechanism, Nicole C. Michael Jan 2015

The Bbc3 Antisense Intragenic Transcript, Bait, Contributes To Puma Expression By A P53-Autonomous Mechanism, Nicole C. Michael

Undergraduate Honors Theses

p53 is a tumor suppressor protein which orchestrates cell cycle arrest or apoptosis to prevent the hyperproliferation of cells which could lead to cancer. However, when p53 is inactivated, which happens in over 50% of cancers, it fails to induce PUMA, a potent apoptotic protein. Loss of PUMA makes cancer cells less likely to undergo apoptosis upon stress stimuli. Recent GRO-seq data revealed unique antisense transcription initiated 6kb into the PUMA locus, creating a small noncoding RNA transcript dubbed BAIT (BBC3 antisense intragenic transcript). This project focused on understanding the expression and function of BAIT, which we hypothesized could modulate ...


Nuclear Pore Component Nup98 Is A Potential Tumor Suppressor And Regulates Posttranscriptional Expression Of Select P53 Target Genes, Stephan Singer, Ruiying Zhao, Anthony M. Barsotti, Anette Ouwehand, Mina Fazollahi, Elias Coutavas, Kai Breuhahn, Olaf Neumann, Thomas Longerich, Tobias Pusterla, Maureen A. Powers, Keith M. Giles, Peter J. Leedman, Jochen Hess, David Grunwald, Harmen J. Bussemaker, Robert H. Singer, Peter Schirmacher, Carol Prives Nov 2014

Nuclear Pore Component Nup98 Is A Potential Tumor Suppressor And Regulates Posttranscriptional Expression Of Select P53 Target Genes, Stephan Singer, Ruiying Zhao, Anthony M. Barsotti, Anette Ouwehand, Mina Fazollahi, Elias Coutavas, Kai Breuhahn, Olaf Neumann, Thomas Longerich, Tobias Pusterla, Maureen A. Powers, Keith M. Giles, Peter J. Leedman, Jochen Hess, David Grunwald, Harmen J. Bussemaker, Robert H. Singer, Peter Schirmacher, Carol Prives

David Grünwald

The p53 tumor suppressor utilizes multiple mechanisms to selectively regulate its myriad target genes, which in turn mediate diverse cellular processes. Here, using conventional and single-molecule mRNA analyses, we demonstrate that the nucleoporin Nup98 is required for full expression of p21, a key effector of the p53 pathway, but not several other p53 target genes. Nup98 regulates p21 mRNA levels by a posttranscriptional mechanism in which a complex containing Nup98 and the p21 mRNA 3'UTR protects p21 mRNA from degradation by the exosome. An in silico approach revealed another p53 target (14-3-3sigma) to be similarly regulated by Nup98. The ...


Sting-Irf3 Pathway Links Endoplasmic Reticulum Stress With Hepatocyte Apoptosis In Early Alcoholic Liver Disease, Jan Petrasek, Arvin Iracheta-Vellve, Timea Csak, Abhishek Satishchandran, Karen Kodys, Evelyn A. Kurt-Jones, Katherine A. Fitzgerald, Gyongyi Szabo Sep 2014

Sting-Irf3 Pathway Links Endoplasmic Reticulum Stress With Hepatocyte Apoptosis In Early Alcoholic Liver Disease, Jan Petrasek, Arvin Iracheta-Vellve, Timea Csak, Abhishek Satishchandran, Karen Kodys, Evelyn A. Kurt-Jones, Katherine A. Fitzgerald, Gyongyi Szabo

Katherine A. Fitzgerald

Emerging evidence suggests that innate immunity drives alcoholic liver disease (ALD) and that the interferon regulatory factor 3 (IRF3),a transcription factor regulating innate immune responses, is indispensable for the development of ALD. Here we report that IRF3 mediates ALD via linking endoplasmic reticulum (ER) stress with apoptotic signaling in hepatocytes. We found that ethanol induced ER stress and triggered the association of IRF3 with the ER adaptor, stimulator of interferon genes (STING), as well as subsequent phosphorylation of IRF3. Activated IRF3 associated with the proapoptotic molecule Bax [B-cell lymphoma 2 (Bcl2)-associated X protein] and contributed to hepatocyte apoptosis ...


Sting-Irf3 Pathway Links Endoplasmic Reticulum Stress With Hepatocyte Apoptosis In Early Alcoholic Liver Disease, Jan Petrasek, Arvin Iracheta-Vellve, Timea Csak, Abhishek Satishchandran, Karen Kodys, Evelyn A. Kurt-Jones, Katherine A. Fitzgerald, Gyongyi Szabo Sep 2014

Sting-Irf3 Pathway Links Endoplasmic Reticulum Stress With Hepatocyte Apoptosis In Early Alcoholic Liver Disease, Jan Petrasek, Arvin Iracheta-Vellve, Timea Csak, Abhishek Satishchandran, Karen Kodys, Evelyn A. Kurt-Jones, Katherine A. Fitzgerald, Gyongyi Szabo

Gyongyi Szabo

Emerging evidence suggests that innate immunity drives alcoholic liver disease (ALD) and that the interferon regulatory factor 3 (IRF3),a transcription factor regulating innate immune responses, is indispensable for the development of ALD. Here we report that IRF3 mediates ALD via linking endoplasmic reticulum (ER) stress with apoptotic signaling in hepatocytes. We found that ethanol induced ER stress and triggered the association of IRF3 with the ER adaptor, stimulator of interferon genes (STING), as well as subsequent phosphorylation of IRF3. Activated IRF3 associated with the proapoptotic molecule Bax [B-cell lymphoma 2 (Bcl2)-associated X protein] and contributed to hepatocyte apoptosis ...


Elucidating The Signalling Pathway Of Mer Tyrosine Kinase Receptor In Efferocytosis, Ekenedelichukwu Azu Aug 2014

Elucidating The Signalling Pathway Of Mer Tyrosine Kinase Receptor In Efferocytosis, Ekenedelichukwu Azu

Electronic Thesis and Dissertation Repository

Efferocytosis is the clearance of apoptotic cells and is necessary for homeostasis. Mer Tyrosine Kinase (MerTK) is a crucial efferocytic receptor whose loss is associated with chronic inflammatory diseases and autoimmunity. While previous studies have shown that MerTK mediates efferocytosis through a unique mechanism that requires integrins, MerTK signalling pathway remains unknown. Given this unusual internalization mechanism, I hypothesized that MerTK signals and engages integrins through a novel signalling pathway different from that used by other phagocytic receptors. Therefore, this study aimed to identify the signalling pathways activated by MerTK, utilizing conventional cell biology and pharmacological approaches.

I found that ...


Characterization Of Efferosome Maturation And The Processing Of Apoptotic Bodies, Yohan Kim Aug 2014

Characterization Of Efferosome Maturation And The Processing Of Apoptotic Bodies, Yohan Kim

Electronic Thesis and Dissertation Repository

Every day billions of cells in our bodies undergo apoptosis and are cleared through efferocytosis – a phagocytosis-like process in which phagocytes engulf and degrade apoptotic cells. Proper processing of efferosomes prevents inflammation and immunogenic presentation of antigens. In this thesis I determined that the early stages of efferosome maturation parallel that of the pro-immunogenic phagocytosis of pathogens. Mass spectrometry analysis of later maturation stages identified unique regulatory proteins on efferosomes and phagosomes. Keys among these were Rab17 and Rab45 on efferosomes versus Rab6b and PI-4-Kinase on phagosomes. The later would allow for antigen presentation from phagosomes, while the former would ...


Investigation Of Rice Bran Derived Anti-Cancer Pentapeptide For Mechanistic Potency In Breast Cancer Cell Models, Ruiqi Li May 2014

Investigation Of Rice Bran Derived Anti-Cancer Pentapeptide For Mechanistic Potency In Breast Cancer Cell Models, Ruiqi Li

Theses and Dissertations

Bioactive peptides derived from food sources with anti-proliferative properties against cancer have drawn more attention in recent years. A pentapeptide derived from rice bran has shown anti-proliferative propertiesagainst human breast cancer cells. The objective of this study was to investigate the mechanistic action of the pentapeptide-induced apoptosis in breast cancer cell models (MCF-7 and MDA-MB-231). The growth inhibition activity of the pentapeptide was

evaluated by MTS[3-(4,5-dimethylthiazol-2-yl)-5-(3- arboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] assayand trypan blue assay in a dose- and time-dependent manner.

The apoptotic properties of pentapeptide-induced apoptosis on cancerous breast cells were evaluated by ...


Cellular Coping Mechanisms To Hypoxia In The Longhorn Sculpin (Myoxocephalus Octodecemspinosus) Brain, Kelly Heino Jan 2014

Cellular Coping Mechanisms To Hypoxia In The Longhorn Sculpin (Myoxocephalus Octodecemspinosus) Brain, Kelly Heino

Electronic Theses and Dissertations

The loss of neurological function due to hypoxia remains to be a challenge in many species due to the lack of knowledge and understanding of cellular responses. To investigate cellular responses and survival strategies of the brain during hypoxia and post-hypoxia recovery in a moderate hypoxia-tolerant species, with the hopes of identifying possible therapeutic remedies, thirty Longhorn sculpin, Myoxocephalus octodecimspinosus, were challenged with acute hypoxia (40% O2 saturation for 1 h) and twelve additional sculpin were used as controls (~90% O2 saturation). Fish were sampled at each of the following time points: control/normoxic conditions (T=0 h); hypoxic ...


Mitochondrial Dynamics: Exploring A Novel Target Against Myocardial Ischemia-Reperfusion Injury, Yi Dong Jan 2014

Mitochondrial Dynamics: Exploring A Novel Target Against Myocardial Ischemia-Reperfusion Injury, Yi Dong

Wayne State University Dissertations

Mitochondrial fusion and fission, collectively termed mitochondrial dynamics, are among the core mechanisms responsible for maintaining mitochondrial health and functional integrity. Dynamin-related protein 1 (DRP1) is a key regulator of mitochondrial fission. Recent studies suggest that i) mitochondrial dynamics, particularly, mitochondrial fission, serves as a mediator of cell fate in the setting of ischemia-reperfusion (IR) injury, and, ii) inhibition of DRP1 and mitochondrial fission provides cardioprotection against IR injury. However, the precise role of DRP1 translocation to mitochondria in the pathogenesis of myocardial ischemia-reperfusion injury has not been established.

Using an established model of hypoxia-reoxygenation (HR) in cultured HL-1 cardiomyocytes ...


Calpain 5: A Non-Classical Calpain Highly Expressed In The Cns And Localized To Mitochondria And Nuclear Pml Bodies, Ranjana Singh Jan 2014

Calpain 5: A Non-Classical Calpain Highly Expressed In The Cns And Localized To Mitochondria And Nuclear Pml Bodies, Ranjana Singh

Theses and Dissertations--Neuroscience

Calpain 5 (CAPN5) is a non-classical member of the calpain family. It lacks the EF-hand motif characteristic of the classical calpains, calpain 1 and 2, but retains catalytic and Ca2+ binding non EF domains. Tra-3, an ortholog of CAPN5, is involved in necrotic cell death in C.elegans; although specific role of CAPN5 has not been investigated in the mammalian CNS. I compared relative mRNA levels of calpains in rat CNS, which revealed that CAPN5 is the second most highly expressed calpain. We examined relative levels of CAPN5 from late embryonic day 18 to postnatal day 90 and found ...


Killerflip: A Novel Lytic Peptide Specifically Inducing Cancer Cell Death, B Pennarun, G. Gaidos, O Bucur, A Tinari Oct 2013

Killerflip: A Novel Lytic Peptide Specifically Inducing Cancer Cell Death, B Pennarun, G. Gaidos, O Bucur, A Tinari

Open Dartmouth: Faculty Open Access Scholarship

One of the objectives in the development of effective cancer therapy is induction of tumor-selective cell death. Toward this end, we have identified a small peptide that, when introduced into cells via a TAT cell-delivery system, shows a remarkably potent cytoxicity in a variety of cancer cell lines and inhibits tumor growth in vivo, whereas sparing normal cells and tissues. This fusion peptide was named killer FLIP as its sequence was derived from the C-terminal domain of c-FLIP, an anti-apoptotic protein. Using structure activity analysis, we determined the minimal bioactive core of killerFLIP, namely killerFLIP-E. Structural analysis of cells using ...


A Novel Autophagy Regulatory Mechanism That Functions During Programmed Cell Death: A Dissertation, Tsun-Kai Chang Sep 2013

A Novel Autophagy Regulatory Mechanism That Functions During Programmed Cell Death: A Dissertation, Tsun-Kai Chang

GSBS Dissertations and Theses

Autophagy is a cellular process that delivers cytoplasmic materials for degradation by the lysosomes. Autophagy-related (Atg) genes were identified in yeast genetic screens for vehicle formation under stress conditions, and Atg genes are conserved from yeast to human. When cells or animals are under stress, autophagy is induced and Atg8 (LC3 in mammal) is activated by E1 activating enzyme Atg7. Atg8-containing membranes form and surround cargos, close and mature to become the autophagosomes. Autophagosomes fuse with lysosomes, and cargos are degraded by lysosomal enzymes to sustain cell viability. Therefore, autophagy is most frequently considered to function in cell survival. Whether ...


P53'S Choice Of Myocardial Death Or Survival: Oxygen Protects Infarct Myocardium By Recruiting P53 On Nos3 Promoter Through Regulation Of P53-Lys118 Acetylation, Rajan Gogna, Esha Madan, Mahmood Khan, Uttam Pati, Periannan Kuppusamy Aug 2013

P53'S Choice Of Myocardial Death Or Survival: Oxygen Protects Infarct Myocardium By Recruiting P53 On Nos3 Promoter Through Regulation Of P53-Lys118 Acetylation, Rajan Gogna, Esha Madan, Mahmood Khan, Uttam Pati, Periannan Kuppusamy

Open Dartmouth: Faculty Open Access Scholarship

Myocardial infarction, an irreversible cardiac tissue damage, involves progressive loss of cardiomyocytes due to p53-mediated apoptosis. Oxygenation is known to promote cardiac survival through activation of NOS3 gene. We hypothesized a dual role for p53, which, depending on oxygenation, can elicit apoptotic death signals or NOS3-mediated survival signals in the infarct heart. p53 exhibited a differential DNA-binding, namely, BAX-p53RE in the infarct heart or NOS3-p53RE in the oxygenated heart, which was regulated by oxygen-induced, post- translational modification of p53. In the infarct heart, p53 was heavily acetylated at Lys118 residue, which was exclusively reversed in the oxygenated heart, apparently regulated ...


Intrinsic Apoptotic Pathway: Effects Of Calcium On Murine Cytochrome C Release In Brain And Liver Mitochondria, Dane M. Edwards Apr 2013

Intrinsic Apoptotic Pathway: Effects Of Calcium On Murine Cytochrome C Release In Brain And Liver Mitochondria, Dane M. Edwards

Senior Honors Theses

A cell may use one of three main apoptotic pathways leading to programmed cell death: the extrinsic pathway, the perforin/granzyme pathway and the intrinsic pathway. The most pertinent to this discussion is the intrinsic pathway, which utilizes the mitochondria as an essential intermediary. Mitochondria’s primary function in relation to this pathway is the subsequent release of pro-apoptotic factors including cytochrome c, which activate a caspase cascade leading to the death of the cell. Cytochrome c is released partly due to an increase in cytosolic calcium levels. Two methods of the release of cytochrome c have been proposed. The ...


Regulation Of The Tumor Suppresser P53 And Survivin By Ras And Ral Gtpases:Implications For Malignant Transformation, Awet G. Tecleab Jan 2013

Regulation Of The Tumor Suppresser P53 And Survivin By Ras And Ral Gtpases:Implications For Malignant Transformation, Awet G. Tecleab

Graduate Theses and Dissertations

Abstract

Although the critical role of the small GTPases Ras and Ral in oncogenesis has been well documented, much remains to be investigated about the molecular mechanism by which these GTPases regulate malignant transformation. The work under this thesis made two major contributions to this field. The first is the discovery that K-Ras, RalA and/or RalB are required for the maintenance of the high levels of the anti-apoptotic protein survivin in some human cancer cells, and the second is the demonstration that down regulation of K-Ras, RalA and/or RalB, but not Raf-1 or Akt1/2, stabilizes the tumor ...


The Multifunctional Protein Daxx: Studies Of Its Biology And Regulation, And Discovery Of A Novel Function, Trisha Agrawal Jan 2013

The Multifunctional Protein Daxx: Studies Of Its Biology And Regulation, And Discovery Of A Novel Function, Trisha Agrawal

Publicly Accessible Penn Dissertations

Daxx, a multifunctional protein with a diverse set of proposed functions, is ubiquitously expressed and highly conserved through evolution. A primarily nuclear protein, Daxx is able to regulate apoptosis, transcription, and cellular proliferation. Despite many studies into the function of Daxx, its precise role in the cell remains enigmatic. Herein, evidence is presented to expand upon the known anti-apoptotic function of Daxx, to establish Daxx as a novel molecular chaperone, and to further its repertoire of transcriptional targets. As an apoptotic inhibitor, Daxx is known to regulate p53 by stabilizing its main negative regulator, Mdm2, via formation of a ternary ...


Next Generation Sequencing Reveals Gene Expression Patterns In The Zebrafish Inner Ear Following Growth Hormone Injection, Gopinath Rajadinakaran Aug 2012

Next Generation Sequencing Reveals Gene Expression Patterns In The Zebrafish Inner Ear Following Growth Hormone Injection, Gopinath Rajadinakaran

Masters Theses & Specialist Projects

Loss of hair cells due to acoustic trauma results in the loss of hearing. In humans, unlike other vertebrates, the mechanism of hair cell regeneration is not possible. The molecular mechanisms that underlie this regeneration in nonmammalian vertebrates remain elusive. To understand the gene regulation during hair cell regeneration, our previous microarray study on zebrafish inner ears found that growth hormone (GH) was significantly upregulated after noise exposure. In this current study, we utilized Next Generation Sequencing (NGS) to examine the genes and pathways that are significantly regulated in the zebrafish inner ear following sound exposure and GH injection. Four ...


Treatment Of Aortic Heart Valve Conduit With Glutamine And Heat Shock As A Means To Deter The Constituent Cellular Population From Becoming Apoptotic, Alyce Marie Linthurst Jones Apr 2012

Treatment Of Aortic Heart Valve Conduit With Glutamine And Heat Shock As A Means To Deter The Constituent Cellular Population From Becoming Apoptotic, Alyce Marie Linthurst Jones

Theses and Dissertations in Biomedical Sciences

Cryopreserved allograft heart valves represent the best solution for a patient with a failing heart valve. However, the constituent cells become apoptotic and within months of transplant the heart valve becomes acellular and the recipient's cells do not repopulate the allograft (3, 51). A strategy to prevent this situation would be to minimize or prevent apoptosis from occurring by strategically altering steps during heart valve processing. Recently it has been demonstrated that: 1) Heat shock protein 70 is a negative modulator of the apoptotic cascade; 2) Cells in culture exposed to hypothermic conditions produce heat shock protein 70 upon ...


Combined Experimental And Computational Analysis Of Dna Damage Signaling Reveals Context-Dependent Roles For Erk In Apoptosis And G1/S Arrest After Genotoxic Stress, Andrea R. Tentner, Michael J. Lee, Gerry J. Ostheimer, Leona D. Samson, Douglas A. Lauffenburger, Michael B. Yaffe Jan 2012

Combined Experimental And Computational Analysis Of Dna Damage Signaling Reveals Context-Dependent Roles For Erk In Apoptosis And G1/S Arrest After Genotoxic Stress, Andrea R. Tentner, Michael J. Lee, Gerry J. Ostheimer, Leona D. Samson, Douglas A. Lauffenburger, Michael B. Yaffe

Program in Systems Biology Publications and Presentations

Following DNA damage, cells display complex multi-pathway signaling dynamics that connect cell-cycle arrest and DNA repair in G1, S, or G2/M phase with phenotypic fate decisions made between survival, cell-cycle re-entry and proliferation, permanent cell-cycle arrest, or cell death. How these phenotypic fate decisions are determined remains poorly understood, but must derive from integrating genotoxic stress signals together with inputs from the local microenvironment. To investigate this in a systematic manner, we undertook a quantitative time-resolved cell signaling and phenotypic response study in U2OS cells receiving doxorubicin-induced DNA damage in the presence or absence of TNFalpha co-treatment; we measured ...


Paternal Mitochondria Elimination And Cell Death Regulation In C. Elegans, Qinghua Zhou Jan 2012

Paternal Mitochondria Elimination And Cell Death Regulation In C. Elegans, Qinghua Zhou

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

The nematode C. elegans is a model organism for various biomedical studies due to its genetic simplicity and conservation with humans. As C. elegans is uniquely amenable to cellular, molecular genetic, and biochemical analyses, many basic biological processes are investigated by experimentally manipulating and observing worms. My thesis describes how I used C. elegans models to advance our understanding of paternal mitochondria elimination and cell death regulation.

Mitochondria are membrane-enclosed organelles that carry their own genome (mtDNA). In mammals, the inheritance of mitochondria and mtDNA is strictly maternal, despite the fact that a sperm can inject up to 100 functional ...


Novel Molecular Mechanisms That Modulate The Cellular Response To P53 Activation, Ryan Edward Henry Jan 2012

Novel Molecular Mechanisms That Modulate The Cellular Response To P53 Activation, Ryan Edward Henry

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

The p53 tumor suppressor protein is the most frequently mutated gene in human tumors and is amongst the most intensely studied molecules in modern biology. p53 acts primarily as a stress-responsive transcription factor that directly regulates the expression of over one hundred target genes, the products of which mediate such tumor suppressive responses as cell cycle arrest, apoptosis, senescence and DNA damage repair. It is well established that p53-dependent cellular stress responses can vary, depending on both the nature of the p53-activating stimulus as well as the cell type experiencing the stress; however, the molecular mechanisms that drive cells to ...


The Drosophila Receptor Tyrosine Kinase Tie Instructs Function Of The Bantam Microrna In The Response To Ionizing Radiation, Amber Bilak Jan 2012

The Drosophila Receptor Tyrosine Kinase Tie Instructs Function Of The Bantam Microrna In The Response To Ionizing Radiation, Amber Bilak

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

Life or death choices of cells in Drosophila depend on the accumulation of critical levels of pro-apoptotic factors such as hid. Ionizing radiation (IR) causes lesions to macromolecules in cells that trigger damage responses and result in death of cells expressing critical amounts of hid. Cells are eliminated by apoptosis to prevent the transfer of damaged genetic material to daughter cells. However, some cells must be preserved in order for organisms to survive and regenerate. Therefore, genes that limit apoptosis can enhance organismal survival. The ban miRNA limits apoptosis after IR exposure by regulating the 3'UTR of hid. Though ...


Hdm2 Small-Molecule Inhibitors For Therapeutic Intervention In B-Cell Lymphoma, Angela Sosin Jan 2012

Hdm2 Small-Molecule Inhibitors For Therapeutic Intervention In B-Cell Lymphoma, Angela Sosin

Wayne State University Dissertations

Lymphomas frequently retain wild-type (wt) p53 function but overexpress HDM2, compromising p53 activity. Therefore, lymphoma is a suitable model for studying therapeutic value of disrupting HDM2-p53 association by small-molecule inhibitors (SMIs). HDM2 SMIs have been developed and are currently under various stages of preclinical and clinical investigation. This study examined various molecular mechanisms associated and biological effects of two different classes of HDM2 SMIs: the spiro-oxindoles (MI-219) and cis-imidazoline (Nutlin-3) in lymphoma cell lines and patient-derived B-lymphoma cells. Surprisingly, results revealed significant quantitative and qualitative differences between these two agents. At the molecular level, effect of Nutlin-3 was generally more ...


Downregulation Of Pax2 Suppresses Ovarian Cancer Cell Growth, Huijuan Song Aug 2011

Downregulation Of Pax2 Suppresses Ovarian Cancer Cell Growth, Huijuan Song

UT GSBS Dissertations and Theses (Open Access)

PAX2 is one of nine PAX genes regulating tissue development and cellular differentiation in embryos. PAX2 promotes cell proliferation, oncogenic transformation, cell-lineage specification, migration, and survival. Unattenuated PAX2 has been found in several cancer types. We therefore sought to elucidate the role of PAX2 in ovarian carcinomas. We found that PAX2 was expressed in low-grade serous, clear cell, endometrioid and mucinous cell ovarian carcinomas, which are relatively chemoresistant compared to high grade serous ovarian carcinomas. Four ovarian cancer cell lines, RMUGL (mucinous), TOV21G (clear cell), MDAH-2774 (endometrioid) and IGROV1 (endometrioid), which express high-levels of PAX2, were used to study the ...


Nanosecond Pulsed Electric Field Induction Of Programmed Cell Death Is Cell Type Dependent: An In Vitro Study, Wei Ren Jul 2011

Nanosecond Pulsed Electric Field Induction Of Programmed Cell Death Is Cell Type Dependent: An In Vitro Study, Wei Ren

Theses and Dissertations in Biomedical Sciences

Nanosecond pulsed electric fields (nsPEFs) present a novel and effective method for cancer ablation by eradicating the ubiquitous cancer hallmark of apoptosis evasion and enforcing cancer programmed cell death. To develop nsPEFs as an anticancer method, a comprehensive understanding of cell death mechanisms is required. The overall objective of this dissertation is to elucidate molecular mechanisms underlying effects of nsPEFs on E4 murine squamous cell carcinoma and human T-cell Jurkat clones that are wildtype, deficient in FADD (ΔFADD) and deficient in caspase-8 (ACas-8). The overall hypothesis is that nsPEFs eliminate cancer cells through activating caspase-dependent and caspase-independent programmed cell death ...


Regulation Of Tgf-Β1-Induced Apoptosis And Epithelial-Mesenchymal Transition By Matrix Rigidity, Jennifer L. Leight May 2011

Regulation Of Tgf-Β1-Induced Apoptosis And Epithelial-Mesenchymal Transition By Matrix Rigidity, Jennifer L. Leight

Publicly Accessible Penn Dissertations

Transforming growth factor-β (TGF-β) plays an important role in several diseases that characteristically involve changes in tissue rigidity, such as cancer and tissue fibrosis. To determine whether matrix rigidity regulates the effects of TGF-β, we examined NMuMG and MDCK epithelial cells cultured on polyacrylamide gels with varying rigidity and treated with TGF-β1. Decreasing matrix rigidity reduced cell spreading and increased TGF-β1-induced apoptosis, while increasing matrix rigidity resulted in epithelial-mesenchymal transition (EMT). To more carefully control cell spreading, microcontact printing was used to restrict ECM area and revealed that reducing cell spreading also increased apoptosis. Apoptosis on compliant substrates was associated ...