Medical Cell Biology Commons^™

Proteomic Profiling Of Serum Derived Exosomes From Prostate Cancer Patients, David Turay

David Turay, MD

Touted among the major achievements in the diagnosis and management of Prostate cancer (PCa) in the past few decades has been, the dramatic decline of men with advanced/metastatic PCa at diagnosis coupled with a significant improvement ( >90%) in the five and ten year survival rates of the disease. Non-palpable PCa (potentially clinically treatable disease) now accounts for 70-80% of all newly diagnosed cases of PCa. Preceding these changes by about a decade was the introduction of Prostatic Specific Antigen (PSA) into clinical practice; first as biomarker for monitoring response to therapy and subsequently as a complementary screening tool. It …

Silencing Of The Pink1 Gene Expression By Conditional Rnai Does Not Induce Dopaminergic Neuron Death In Mice., Hongxia Zhou, Björn H Falkenburger, Jörg B Schulz, Kim Tieu, Zuoshang Xu, Xu Gang Xia

Kim Tieu

Transgenic RNAi, an alternative to the gene knockout approach, can induce hypomorphic phenotypes that resemble those of the gene knockout in mice. Conditional transgenic RNAi is an attractive choice of method for reverse genetics in vivo because it can achieve temporal and spatial silencing of targeted genes. Pol III promoters such as U6 are widely used to drive the expression of RNAi transgenes in animals. Tested in transgenic mice, a Cre-loxP inducible U6 promoter drove the broad expression of an shRNA against the Pink1 gene whose loss-of-functional mutations cause one form of familial Parkinson's disease. The expression of the shRNA …

Temporal Changes In Innate Immune Signals In A Rat Model Of Alcohol Withdrawal In Emotional And Cardiorespiratory Homeostatic Nuclei., Kate Freeman, Anthony Brureau, Rajanikanth Vadigepalli, Mary M Staehle, Melanie M Brureau, Gregory E Gonye, Jan B Hoek, D Craig Hooper, James S Schwaber

Mary Staehle

BACKGROUND: Chronic alcohol use changes the brain's inflammatory state. However, there is little work examining the progression of the cytokine response during alcohol withdrawal, a period of profound autonomic and emotional upset. This study examines the inflammatory response in the central nucleus of the amygdala (CeA) and dorsal vagal complex (DVC), brain regions neuroanatomically associated with affective and cardiorespiratory regulation in an in vivo rat model of withdrawal following a single chronic exposure.

METHODS: For qRT-PCR studies, we measured the expression of TNF-α, NOS-2, Ccl2 (MCP-1), MHC II invariant chain CD74, and the TNF receptor Tnfrsf1a in CeA and DVC …

Capsaicin Displays Anti-Proliferative Activity Against Human Small Cell Lung Cancer In Cell Culture And Nude Mice Models Via The E2f Pathway, Kathleen C. Brown, Theodore R. Witte, W. Elaine Hardman, Haitao Luo, Yi C. Chen, A. Betts Carpenter, Jamie K. Lau, Piyali Dasgupta

Kathleen C. Brown

Background: Small cell lung cancer (SCLC) is characterized by rapid progression and low survival rates. Therefore, novel therapeutic agents are urgently needed for this disease. Capsaicin, the active ingredient of chilli peppers, displays antiproliferative activity in prostate and epidermoid cancer in vitro. However, the anti-proliferative activity of capsaicin has not been studied in human SCLCs. The present manuscript fills this void of knowledge and explores the anti-proliferative effect of capsaicin in SCLC in vitro and in vivo. Methodology/Principal Findings: BrdU assays and PCNA ELISAs showed that capsaicin displays robust anti-proliferative activity in four human SCLC cell lines. Furthermore, capsaicin potently …

Impact Of The C-Mybe308g Mutation On Mouse Myelopoiesis And Dendritic Cell Development, Peter Papathanasiou, Sawang Petvises, Ying-Ying Hey, Andrew C Perkins, Helen C O'Neill

Helen O'Neill

Booreana mice carrying the c-Myb308G point mutation were analyzed to determine changes in early hematopoiesis in the bone marrow and among mature cells in the periphery. This point mutation led to increased numbers of early hematopoietic stem and progenitor cells (HSPCs), with a subsequent reduction in the development of B cells, erythroid cells, and neutrophils, and increased numbers of myeloid cells and granulocytes. Myelopoiesis was further investigated by way of particular subsets affected. A specific question addressed whether booreana mice contained increased numbers of dendritic-like cells (L-DC subset) recently identified in the spleen, since L-DCs arise in vitro by direct …

The Glia Response After Peripheral Nerve Injury: A Comparison Between Schwann Cells And Olfactory Ensheathing Cells And Their Uses For Neural Regenerative Therapies, Matthew J Barton, James St John, Alison Wright, Jenny Ekberg

Jenny Ekberg

The peripheral nervous system (PNS) exhibits a much larger capacity for regeneration than the central nervous system (CNS). One reason for this difference is the difference in glial cell types between the two systems. PNS glia respond rapidly to nerve injury by clearing debris from the injury site, supplying essential growth factors and providing structural support; all of which enhances neuronal regeneration. Thus, transplantation of glial cells from the PNS is a very promising therapy for injuries to both the PNS and the CNS. There are two key types of PNS glia: olfactory ensheathing cells (OECs), which populate the olfactory …

Delaying Chemotherapy In The Treatment Of Stage Iv Non-Small Cell Lung Cancer Does Not Adversely Affect Survival Outcome, Mohammad Mozayen Md, Mohamed Alsharedi, Inderjit Mehmi, Todd W. Gress Md, Maria Tria Tirona Md

Mohamed Alsharedi

Background: Whether a delay in the initiation of chemotherapy for advanced non-small cell lung cancer (NSCLC) can affect overall survival is not well studied. We aim to evaluate the effect of the time interval between diagnosis and initiation of chemotherapy on overall survival in patients with stage IV NSCLC. Methods: A retrospective review of newly diagnosed stage IV NSCLC patients who received chemotherapy between 1995 and 2012 was conducted. Demographics, histology and site(s) of metastases of patients were reviewed. Time interval between the date of diagnosis and the date of starting chemotherapy was calculated in days. Patients were divided in …

Delaying Chemotherapy In The Treatment Of Stage Iv Non-Small Cell Lung Cancer Does Not Adversely Affect Survival Outcome, Mohammad Mozayen Md, Mohamed Alsharedi, Inderjit Mehmi, Todd W. Gress Md, Maria Tria Tirona Md

Maria Tirona

Background: Whether a delay in the initiation of chemotherapy for advanced non-small cell lung cancer (NSCLC) can affect overall survival is not well studied. We aim to evaluate the effect of the time interval between diagnosis and initiation of chemotherapy on overall survival in patients with stage IV NSCLC. Methods: A retrospective review of newly diagnosed stage IV NSCLC patients who received chemotherapy between 1995 and 2012 was conducted. Demographics, histology and site(s) of metastases of patients were reviewed. Time interval between the date of diagnosis and the date of starting chemotherapy was calculated in days. Patients were divided in …

Feasibility Of Atrial Delivery And Tracking Of Stem Cells In A Porcine Model, Nina Garlie, Timothy Hacker, Eric G. Schmuck, Jill Koch, Jayant Khitha, Amish Raval, Indrajit Choudhuri

Indrajit Choudhuri, MD

Background: Many patients undergoing open heart surgery have sinus node dysfunction and atrial fibrillation, leading to adverse outcomes. Mesenchymal stem cells (MSC) delivered at the time of surgery may have a reparative effect on atrial tissue, thereby improving sinus node function and reducing or preventing atrial fibrillation. Stem cell delivery to the atrium is entirely unstudied. This is a significant gap in medical research, as atrial disease contributes significantly to health care costs. Purpose: The purpose of this pilot study is to establish a technique to deliver MSC to the atria through an open-chest model, to assess the safety of …

Expression Of Heme Oxygenase-1 In Thick Ascending Loop Of Henle Attenuates Angiotensin Ii-Dependent Hypertension, David E. Stec, Heather A. Drummond, Moneete U. Gousette, Megan V. Storm, Nader G. Abraham, Eva Csongradi

Nader G. Abraham

Kidney-specific induction of heme oxygenase-1 (HO-1) attenuates the development of angiotensin II (Ang II) -dependent hypertension, but the relative contribution of vascular versus tubular induction of HO-1 is unknown. To determine the specific contribution of thick ascending loop of Henle (TALH) -derived HO-1, we generated a transgenic mouse in which the uromodulin promoter controlled expression of human HO-1. Quantitative RT-PCR and confocal microscopy confirmed successful localization of the HO-1 transgene to TALH tubule segments. Medullary HO activity, but not cortical HO activity, was significantly higher in transgenic mice than control mice. Enhanced TALH HO-1 attenuated the hypertension induced by Ang …

Ho-1 Induction Improves The Type-1 Cardiorenal Syndrome In Mice With Impaired Angiotensin Ii–Induced Lymphocyte Activation, Sumit R. Monu, Paola Pesce, Komal Sodhi, Massimo Boldrin, Nitin Puri, Larisa Fedorova, David Sacerdoti, Stephen J. Peterson, Nader G. Abraham, Attallah Kappas

Nader G. Abraham

Type-1 cardiorenal syndrome, characterized by acute kidney dysfunction secondary to cardiac failure and renal arteriolar vasoconstriction, is mediated by the renin–angiotensin–aldosterone axis and sympathetic nervous system activation. Previous reports indicate that angiotensin II modulates immune function and causes recruitment and activation of T-lymphocytes. The goal of this study was to evaluate the effects of postischemic heart failure on renal morphology and circulation and the beneficial effects of heme oxygenase-1 (HO-1) induction in T-lymphocyte–suppressed severe combined immune deficiency (SCID) mice. Mice were divided into 4 groups: sham, myocardial infarction (MI), MI treated with an HO-1 inducer, cobalt protoporphyrin, and with or …

The Cell Surface Receptor Slam Controls T Cell And Macrophage Functions, Ninghai Wang, Abhay Satoskar, William Faubion, Susumu Okamoto, Stefan Feske, Charles A. Gullo Phd, Kareem Clarke, Miriam Rodriguez Sosa, Arlene H. Sharpe, Cox Terhorst

Charles Gullo

Signaling lymphocyte activation molecule (SLAM), a glycoprotein expressed on activated lymphocytes and antigen-presenting cells, has been shown to be a coregulator of antigen-driven T cell responses and is one of the two receptors for measles virus. Here we show that T cell receptor–induced interleukin (IL)-4 secretion by SLAM−/− CD4+ cells is down-regulated, whereas interferon γ production by CD4+ T cells is only slightly up-regulated. Although SLAM controls production of IL-12, tumor necrosis factor, and nitric oxide in response to lipopolysaccharide (LPS) by macrophages, SLAM does not regulate phagocytosis and responses to peptidoglycan or CpG. Thus, SLAM acts as a coreceptor …

Inhibition Of Proliferation And Induction Of Apoptosis In Multiple Myeloma Cell Lines By Cd137 Ligand Signaling, Charles A. Gullo Phd, Liang Kai Koh, Wan Lu Pang, Kian Tong Ho, Shi Hao Tan, Herbert Schwarz

Charles Gullo

Background Multiple myeloma (MM) is a malignancy of terminally-differentiated plasma cells, and the second most prevalent blood cancer. At present there is no cure for MM, and the average prognosis is only three to five years. Current treatments such as chemotherapy are able to prolong a patient's life but rarely prevent relapse of the disease. Even hematopoietic stem cell transplants and novel drug combinations are often not curative, underscoring the need for a continued search for novel therapeutics. CD137 and its ligand are members of the Tumor Necrosis Factor (TNF) receptor and TNF superfamilies, respectively. Since CD137 ligand cross-linking enhances …

Canine Rd3 Mutation Establishes Rod-Cone Dysplasia Type 2 (Rcd2) As Ortholog Of Human And Murine Rd3, Anna V. Kukekova, Orly Goldstein, Jennifer L. Johnson, Malcolm A. Richardson, Susan E. Pearce-Kelling, Anand Swaroop, James S. Friedman, Gustavo D. Aguirre, Gregory M. Acland

Gustavo D. Aguirre, VMD, PhD

Rod-cone dysplasia type 2 (rcd2) is an autosomal recessive disorder that segregates in collie dogs. Linkage disequilibrium and meiotic linkage mapping were combined to take advantage of population structure within this breed and to fine map rcd2 to a 230-kb candidate region that included the gene C1orf36 responsible for human and murine rd3, and within which all affected dogs were homozygous for one haplotype. In one of three identified canine retinal RD3 splice variants, an insertion was found that cosegregates with rcd2 and is predicted to alter the last 61 codons of the normal open reading frame and further extend …

Clinical Light Exposure, Photoreceptor Degeneration, And Ap-1 Activation: A Cell Death Or Cell Survival Signal In The Rhodopsin Mutant Retina?, Danian Gu, William Beltran, Zexiao Li, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

PURPOSE. The T4R RHO mutant dog retina shows retinal degeneration with exposures to light comparable to those used in clinical eye examinations of patients. To define the molecular mechanisms of the degeneration, AP-1 DNA-binding activity, composition, posttranslational modification of the protein complex, and modulation of ERK/MAPK signaling pathways were examined in light-exposed mutant retinas. METHODS. Dark-adapted retinas were exposed to short-duration light flashes from a retinal camera used clinically for retinal photography and were collected at different time points after exposure. Electrophoretic mobility shift assay (EMSA), supershift EMSA, Western blot analysis, and immunocytochemistry were used to examine AP-1 signaling. RESULTS. …

Development And Validation Of A Canine-Specific Profiling Array To Examine Expression Of Pro-Apoptotic And Pro-Survival Genes In Retinal Degenerative Diseases, Sem Genini, William Beltran, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

We developed an expression profiling array to examine pro-apoptotic and pro-survival genes in dog retinal degeneration models. Gene-specific canine TaqMan assays were developed and included in a custom real-time quantitative reverse transcription-PCR (qRT-PCR) array. Of the 96 selected genes, 93 belonged to known relevant pro-apoptotic and pro-survival pathways, and/or were positive controls expressed in retina, while three were housekeeping genes. Ingenuity Pathway Analysis (IPA) showed that the selected genes belonged to expected biological functions (cell death, cell-mediated immune response, cellular development, function, and maintenance) and pathways (death receptor signaling, apoptosis, TNFR1 signaling, and induction of apoptosis by HIV1). Validation of …

Steroids Do Not Prevent Photoreceptor Degeneration In The Light-Exposed T4r Rhodopsin Mutant Dog Retina Irrespective Of Ap-1 Inhibition, Danian Gu, William Beltran, Sue Pearce-Kelling, Zexiao Li, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

PURPOSE. AP-1 has been proposed as a key intermediate linking exposure to light and photoreceptor cell death in rodent light-damage models. Inhibition of AP-1 associated with steroid administration also prevents light damage. In this study the role of steroids in inhibiting AP-1 activation and/or in preventing photoreceptor degeneration was examined in the rhodopsin mutant dog model. METHODS. The dogs were dark adapted overnight, eyes dilated with mydriatics; the right eye was light occluded and the fundus of the left eye photographed (∼15–17 overlapping frames) with a fundus camera. For biochemical studies, the dogs remained in the dark for 1 to …

Age-Dependent Disease Expression Determines Remodeling Of The Retinal Mosaic In Carriers Of Rpgr Exon Orfn15 Mutations, William Beltran, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

PURPOSE. To characterize the retinal histopathology in carriers of X-linked progressive retinal atrophy (XLPRA1 and XLPRA2), two canine models of X-linked retinitis pigmentosa caused, respectively, by a stop and a frameshift mutation in RPGRORF15. METHODS. Retinas of XLPRA2 and XLPRA1 carriers of different ages were processed for morphologic evaluation, TUNEL assay, and immunohistochemistry. Cell-specific markers were used to examine retinal remodeling events. RESULTS. A mosaic pattern composed of patches of diseased and normal retina was first detected in XLPRA2 carriers at 4.9 weeks of age. A peak of photoreceptor cell death led to focal rod loss; however, in these patches …

Blinded By The Light: Retinal Phototoxicity In The Context Of Safety Studies, Maria Cristina De Vera Mudry, Sven Kronenberg, Shun-Ichiro Komatsu, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

No abstract provided.

Prieurianin Causes Weight Loss In Diet-Induced Obese Mice And Inhibits Adipogenesis In Cultured Preadipocytes, Ahmed Kablan, Rudel A. Saunders, Maria Szkudlarek-Mikho, Andrew J.B. Chin, Raul M. Bosio, Kazuyuki Fujii, Joseph I. Shapiro M.D., Khew-Voon Chin

Joseph I Shapiro MD

The global increase in the incidence of obesity has emerged as one of the most serious public health risks in recent years. Despite the enormity of the obesity pandemic, there are currently only two FDA-approved therapies for its treatment and these drugs exhibit modest effi cacy and have limiting side effects. Prieurianin is a plant limonoid product that deters feeding in insect larvae. We investigated in this study the effects of prieurianin on weight loss and adipogenesis. Our results showed that prieurianin causes weight loss by reducing energy intake in obese mice on highcalorie diet. We also found that prieurianin …

Down-Regulation Of The Transcription Factor Snail In The Placentas Of Patients With Preeclampsia And In A Rat Model Of Preeclampsia, Larissa Federova, Cara Gatto-Weis, Sleiman Smaili, Nauman Khurshid, Joseph I. Shapiro M.D., Deepak Malhorta, Terrence Horrigan

Joseph I Shapiro MD

Background: Placental malfunction in preeclampsia is believed to be a consequence of aberrant differentiation of trophoblast lineages and changes in utero-placental oxygenation. The transcription factor Snail, a master regulator molecule of epithelial-mesenchymal transition in embryonic development and in cancer, is shown to be involved in trophoblast differentiation as well. Moreover, Snail can be controlled by oxidative stress and hypoxia. Therefore, we examined the expression of Snail and its downstream target, e-cadherin, in human normal term, preterm and preeclamptic placentas, and in pregnant rats that developed preeclampsia-like symptoms in the response to a 20- fold increase in sodium intake. Methods: Western …

The B Subunit Of Escherichia Coli Heat-Labile Toxin Alters The Development And Antigen-Presenting Capacity Of Dendritic Cells, Jing Ji, Kristin Grifftiths, Peter Milburn, Timothy Hirst, Helen O'Neill

Helen O'Neill

Escherichia coli's heat-labile enterotoxin (Etx) and its non-toxic B subunit (EtxB) have been characterized as adjuvants capable of enhancing T cell responses to co-administered antigen. Here, we investigate the direct effect of intravenously administered EtxB on the size of the dendritic and myeloid cell populations in spleen. EtxB treatment appears to enhance the development and turnover of dendritic and myeloid cells from precursors within the spleen. EtxB treatment also gives a dendritic cell (DC) population with higher viability and lower activation status based on the reduced expression of MHC-II, CD80 and CD86. In this respect, the in vivo effect of …

Na/K-Atpase Mimetic Pnaktide Peptide Inhibits The Growth Of Human Cancer Cells, Zhichuan Li, Zhongbing Zhang, Joe X. Xie, Xin Li, Jiang Tian, Ting Cai, Hongaun Cui, Hanfei Ding, Joseph I. Shapiro Md, Zijian Xie

Zijian Xie

Cells contain a large pool of non-pumping Na/K-ATPase that participates in signal transduction. Here, we show that the expression of α1 Na/K-ATPase is significantly reduced in human prostate carcinoma as well as in several human cancer cell lines. This down-regulation impairs the ability of Na/K-ATPase to regulate Src-related signaling processes. Supplement of pNaKtide, a peptide derived from α1 Na/K-ATPase, reduces activities of Src and Src effectors. Consequently, these treatments stimulate apoptosis and inhibit growth in cultures of human cancer cells. Moreover, administration of pNaKtide inhibits angiogenesis and growth of tumor xenograft. Thus, the new findings demonstrate the in vivo effectiveness …

Na/K-Atpase Mimetic Pnaktide Peptide Inhibits The Growth Of Human Cancer Cells, Zhichuan Li, Zhongbing Zhang, Joe X. Xie, Xin Li, Jiang Tian, Ting Cai, Hongaun Cui, Hanfei Ding, Joseph I. Shapiro Md, Zijian Xie

Joseph I Shapiro MD

Cells contain a large pool of non-pumping Na/K-ATPase that participates in signal transduction. Here, we show that the expression of α1 Na/K-ATPase is significantly reduced in human prostate carcinoma as well as in several human cancer cell lines. This down-regulation impairs the ability of Na/K-ATPase to regulate Src-related signaling processes. Supplement of pNaKtide, a peptide derived from α1 Na/K-ATPase, reduces activities of Src and Src effectors. Consequently, these treatments stimulate apoptosis and inhibit growth in cultures of human cancer cells. Moreover, administration of pNaKtide inhibits angiogenesis and growth of tumor xenograft. Thus, the new findings demonstrate the in vivo effectiveness …

Mir-30b/30d Regulation Of Galnac Transferases Enhances Invasion And Immunosuppression During Metastasis, Avital Gaziel-Sovran, Miguel Segura, Raffaella Di Micco, Mary Collins, Douglas Hanniford, Eleazar De Miera, John Rakus, John Dankert, Shulian Shang, Robert Kerbel, Nina Bhardwaj, Yongzhao Shao, Farbod Darvishian, Jiri Zavadil, Adrian Erlebacher, Lara Mahal, Iman Osman, Eva Hernando

John F. Rakus

To metastasize, a tumor cell must acquire abilities such as the capacity to colonize new tissue and evade immune surveillance. Recent evidence suggests that microRNAs can promote the evolution of malignant behaviors by regulating multiple targets. We performed a microRNA analysis of human melanoma, a highly invasive cancer, and found that miR-30b/30d upregulation correlates with stage, metastatic potential, shorter time to recurrence, and reduced overall survival. Ectopic expression of miR-30b/30d promoted the metastatic behavior of melanoma cells by directly targeting the GalNAc transferase GALNT7, resulted in increased synthesis of the immunosuppressive cytokine IL-10, and reduced immune cell activation and recruitment. …

Natural Killer Cells In Patients With Severe Chronic Fatigue Syndrome, Ekua Brenu, Sharni Hardcastle, Gunn Atkinson, Mieke Van Driel, Sanne Kreijkamp-Kaspers, Kevin Ashton, Don Staines, Sonja Marshall-Gradisnik

Kevin Ashton

Maintenance of health and physiological homeostasis is a synergistic process involving tight regulation of proteins, transcription factors and other molecular processes. The immune system consists of innate and adaptive immune cells that are required to sustain immunity. The presence of pathogens and tumour cells activates innate immune cells, in particular Natural Killer (NK) cells. Stochastic expression of NK receptors activates either inhibitory or activating signals and results in cytokine production and activation of pathways that result in apoptosis of target cells. Thus, NK cells are a necessary component of the immunological process and aberrations in their functional processes, including equivocal …

A Comparison Of Four Electrical Stimulation Types On Staphylococcus Aureus Growth In Vitro, Harold Merriman, Chris Hegyi, Cheryl Albright-Overton, John Carlos, Robert Putnam, Janet Mulcare

Harold L. Merriman

We evaluated the efficacy of common electrical stimulation (ES) types on bacterial growth in vitro using clinically relevant conditions. Four types of ES-continuous microamperage direct current (µADC), high-voltage pulsed current (HVPC), low-voltage monophasic milliamperage pulsed current (LVMmAPC), and low-voltage biphasic milliamperage pulsed current (LVBmAPC)-were each applied to a separate set of culture plates containing Staphylococcus aureus for 1 h at 37 °C on 3 consecutive days. After ES treatment, the zone of inhibition surrounding each electrode was measured. Zone of inhibition measurements showed a significant inhibitory effect for continuous µADC and HVPC (p < 0.05), but not for LVMmAPC and LVBmAPC. …

Iron Alters Cell Survival In A Mitochondria-Dependent Pathway In Ovarian Cancer Cells., Edward Haller

Edward Haller

ABSTRACT The role of iron in the development of cancer remains unclear. We previously reported that iron reduces cell survival in a Ras/mitogen-activated protein kinase (MAPK)-dependent manner in ovarian cells; however, the underlying downstream pathway leading to reduced survival was unclear. Although levels of intracellular iron, ferritin/CD71 protein and reactive oxygen species did not correlate with iron-induced cell survival changes, we identified mitochondrial damage (via TEM) and reduced expression of outer mitochondrial membrane proteins (translocase of outer membrane: TOM20 and TOM70) in cell lines sensitive to iron. Interestingly, Ru360 (an inhibitor of the mitochondrial calcium uniporter) reversed mitochondrial changes and …

Emergence Of Bimodal Cell Population Responses From The Interplay Between Analog Single-Cell Signaling And Protein Expression Noise., Marc R Birtwistle, Jens Rauch, Anatoly Kiyatkin, Edita Aksamitiene, Maciej Dobrzyński, Jan Hoek, Walter Kolch, Babatunde A Ogunnaike, Boris N Kholodenko

Anatoly Kiyatkin

BACKGROUND: Cell-to-cell variability in protein expression can be large, and its propagation through signaling networks affects biological outcomes. Here, we apply deterministic and probabilistic models and biochemical measurements to study how network topologies and cell-to-cell protein abundance variations interact to shape signaling responses. RESULTS: We observe bimodal distributions of extracellular signal-regulated kinase (ERK) responses to epidermal growth factor (EGF) stimulation, which are generally thought to indicate bistable or ultrasensitive signaling behavior in single cells. Surprisingly, we find that a simple MAPK/ERK-cascade model with negative feedback that displays graded, analog ERK responses at a single cell level can explain the experimentally …

Deferasirox Decreases Age-Associated Iron Accumulation In The Aging F344bn Rat Heart, Ravi K. Arvapalli

Ravi K. Arvapalli

It is thought that aging in rats and humans is associated with increases in iron accumulation and these increases in iron may be associated with increased cellular apoptosis. Here we examine the relationship between cardiac iron levels and cardiomyocyte apoptosis in aged F344BN rats which were treated with an oral iron chelator (Deferasirox; 100mg/kg body. weight/day) for 6 months. Compared with 6- month controls, the levels of cardiac iron, cardiac apoptosis, FLC and DMT-1 were higher in 33-month hearts. Deferasirox treatment for six months decreased cardiac iron and this was associated with decreases in the number of apoptotic cardiac myocytes. …