Molecular Model of Prion Transmission to Humans

PubMed Central

Wight, Darren; Barron, Rona; Jeffrey, Martin; Manson, Jean; Prowse, Christopher; Ironside, James W.; Head, Mark W.

2009-01-01

To assess interspecies barriers to transmission of transmissible spongiform encephalopathies, we investigated the ability of disease-associated prion proteins (PrPd) to initiate conversion of the human normal cellular form of prion protein of the 3 major PRNP polymorphic variants in vitro. Protein misfolding cyclic amplification showed that conformation of PrPd partly determines host susceptibility. PMID:19961689

Embryological Development: Evolutionary History, Genetic Bias, and Cellular Environment Control the Flow of Developmental Events. Part I.

ERIC Educational Resources Information Center

Caplan, Arnold I.

1981-01-01

Describes development of the limb and various interactions necessary for the expression of its unique form and phenotypes to uncover the hierarchical controlling steps in the development process for the potential of avoiding abnormal events and manipulating what might be detrimental genetic events into a normal sequence. (Author/SK)

Clinical features in prion protein-deficient and wild-type cattle inoculated with transmissible mink encephalopathy (TME)

USDA-ARS?s Scientific Manuscript database

Background: Transmissible spongiform encephalopathies (TSEs) or prion diseases are caused by the propagation of a misfolded form (PrP**d) of the normal cellular prion protein, PrP**c. Recently, we have reported the generation and characterization of PrP**C-deficient cattle (PrP-/-) produced by a seq...

Histomorphometric analysis of nuclear and cellular volumetric alterations in oral lichen planus, lichenoid lesions and normal oral mucosa using image analysis software.

PubMed

Venkatesiah, Sowmya S; Kale, Alka D; Hallikeremath, Seema R; Kotrashetti, Vijayalakshmi S

2013-01-01

Lichen planus is a chronic inflammatory mucocutaneous disease that clinically and histologically resembles lichenoid lesions, although the latter has a different etiology. Though criteria have been suggested for differentiating oral lichen planus from lichenoid lesions, confusion still prevails. To study the cellular and nuclear volumetric features in the epithelium of normal mucosa, lichen planus, and lichenoid lesions to determine variations if any. A retrospective study was done on 25 histologically diagnosed cases each of oral lichen planus, oral lichenoid lesions, and normal oral mucosa. Cellular and nuclear morphometric measurements were assessed on hematoxylin and eosin sections using image analysis software. Analysis of variance test (ANOVA) and Tukey's post-hoc test. The basal cells of oral lichen planus showed a significant increase in the mean nuclear and cellular areas, and in nuclear volume; there was a significant decrease in the nuclear-cytoplasmic ratio as compared to normal mucosa. The suprabasal cells showed a significant increase in nuclear and cellular areas, nuclear diameter, and nuclear and cellular volumes as compared to normal mucosa. The basal cells of oral lichenoid lesions showed significant difference in the mean cellular area and the mean nuclear-cytoplasmic ratio as compared to normal mucosa, whereas the suprabasal cells differed significantly from normal mucosa in the mean nuclear area and the nuclear and cellular volumes. Morphometry can differentiate lesions of oral lichen planus and oral lichenoid lesions from normal oral mucosa. Thus, morphometry may serve to discriminate between normal and premalignant lichen planus and lichenoid lesions. These lesions might have a high risk for malignant transformation and may behave in a similar manner with respect to malignant transformation.

[The bacteriological and immunological efficacy of biosporin in nonspecific ulcerative colitis].

PubMed

Cherniakova, V I; Bereza, N M; Selezneva, S I; Chaplinskiĭ, V Ia; Kudriavtseva, V E; Mosalova, N M; Shevtsova, Z I; Tropko, L V; Boĭko, T I

1993-01-01

The results from examination of intestinal microflora and immune status in 75 patients with nonspecific ulcerative colitis with different degree of disease seriousness are presented. The deviations in the composition of normal microflora were primarily expressed in a decrease of the number of bifidobacteria. In 64.9% of patients the disease proceeded against the background of deficit of T-cellular immunity link. The sufficiently expressed bacteriological and immunological efficiency of complex therapy including preparation from spore-forming bacteria as a normalizer of microflora is shown.

Wavelet-based multiscale analysis of bioimpedance data measured by electric cell-substrate impedance sensing for classification of cancerous and normal cells.

PubMed

Das, Debanjan; Shiladitya, Kumar; Biswas, Karabi; Dutta, Pranab Kumar; Parekh, Aditya; Mandal, Mahitosh; Das, Soumen

2015-12-01

The paper presents a study to differentiate normal and cancerous cells using label-free bioimpedance signal measured by electric cell-substrate impedance sensing. The real-time-measured bioimpedance data of human breast cancer cells and human epithelial normal cells employs fluctuations of impedance value due to cellular micromotions resulting from dynamic structural rearrangement of membrane protrusions under nonagitated condition. Here, a wavelet-based multiscale quantitative analysis technique has been applied to analyze the fluctuations in bioimpedance. The study demonstrates a method to classify cancerous and normal cells from the signature of their impedance fluctuations. The fluctuations associated with cellular micromotion are quantified in terms of cellular energy, cellular power dissipation, and cellular moments. The cellular energy and power dissipation are found higher for cancerous cells associated with higher micromotions in cancer cells. The initial study suggests that proposed wavelet-based quantitative technique promises to be an effective method to analyze real-time bioimpedance signal for distinguishing cancer and normal cells.

Extracellular matrix structure.

PubMed

Theocharis, Achilleas D; Skandalis, Spyros S; Gialeli, Chrysostomi; Karamanos, Nikos K

2016-02-01

Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation, and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented. Copyright © 2015 Elsevier B.V. All rights reserved.

Use of bovine recombinant prion protein and real-time quaking-induced conversion to detect transmissible mink encephalopathy prions and discriminate classical and atypical L- and H-type bovine spongiform encephalopathy

USDA-ARS?s Scientific Manuscript database

Prions are amyloid-forming proteins that cause transmissible spongiform encephalopathies through a process involving conversion from normal cellular prion protein to pathogenic misfolded conformation. This conversion has been used for in vitro assays including serial protein misfolding amplification...

76 FR 48172 - Prospective Grant of Exclusive License: Use of PKM2 Activators for the Treatment of Cancer

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-08

...: The fetal form of Pyruvate Kinase, called PKM2, is expressed in all cancer cells and imparts an important metabolic change on cancer cells which allows them to grow and divide rapidly. That is, PKM2 is normally inactive, which allows cancer cells to create an abundance of molecules for cellular growth and...

SIRT3 Links Oxidative Stress with Aging and Cancer | Center for Cancer Research

Cancer.gov

When cells produce energy, they also form reactive oxygen molecules capable of damaging proteins and DNA. Normally, these molecules are neutralized by a protein called superoxide dismutase, or SOD. However, as a cell ages, oxidative damage accumulates. The increase in oxidative cellular damage as people age may provide a mechanistic connection between aging and carcinogenesis.

Novel antioxidants are not toxic to normal tissues but effectively kill cancer cells.

PubMed

Kovalchuk, Anna; Aladedunye, Felix; Rodriguez-Juarez, Rocio; Li, Dongping; Thomas, James; Kovalchuk, Olga; Przybylski, Roman

2013-10-01

Free radicals are formed as a result of cellular processes and play a key role in predisposition to and development of numerous diseases and of premature aging. Recently, we reported the syntheses of a number of novel phenolic antioxidants for possible application in food industry. In the present study, analyses of the cellular processes and molecular gene expression effects of some of the novel antioxidants in normal human tissues and in cancer cells were undertaken. Results indicated that whereas the examined antioxidants showed no effects on morphology and gene expression of normal human oral and gingival epithelial tissues, they exerted a profound cell killing effect on breast cancer cells, including on chemotherapy-resistant breast cancer cells and on oral squamous carcinoma cells. Among the tested antioxidants, N-decyl-N-(3-methoxy-4-hydroxybenzyl)-3-(3,4-dihydroxyphenyl) propanamide and N-decyl-N-(3,5-dimethoxy-4-hydroxybenzyl)-3-(3,4-dihydroxyphenyl) propanamide were the most promising, with excellent potential for cancer treatment. Moreover, our gene expression databases can be used as a roadmap for future analysis of mechanisms of antioxidant action.

Chronic Lymphocytic Leukemia B-Cell Normal Cellular Counterpart: Clues From a Functional Perspective

PubMed Central

Darwiche, Walaa; Gubler, Brigitte; Marolleau, Jean-Pierre; Ghamlouch, Hussein

2018-01-01

Chronic lymphocytic leukemia (CLL) is characterized by the clonal expansion of small mature-looking CD19+ CD23+ CD5+ B-cells that accumulate in the blood, bone marrow, and lymphoid organs. To date, no consensus has been reached concerning the normal cellular counterpart of CLL B-cells and several B-cell types have been proposed. CLL B-cells have remarkable phenotypic and gene expression profile homogeneity. In recent years, the molecular and cellular biology of CLL has been enriched by seminal insights that are leading to a better understanding of the natural history of the disease. Immunophenotypic and molecular approaches (including immunoglobulin heavy-chain variable gene mutational status, transcriptional and epigenetic profiling) comparing the normal B-cell subset and CLL B-cells provide some new insights into the normal cellular counterpart. Functional characteristics (including activation requirements and propensity for plasma cell differentiation) of CLL B-cells have now been investigated for 50 years. B-cell subsets differ substantially in terms of their functional features. Analysis of shared functional characteristics may reveal similarities between normal B-cell subsets and CLL B-cells, allowing speculative assignment of a normal cellular counterpart for CLL B-cells. In this review, we summarize current data regarding peripheral B-cell differentiation and human B-cell subsets and suggest possibilities for a normal cellular counterpart based on the functional characteristics of CLL B-cells. However, a definitive normal cellular counterpart cannot be attributed on the basis of the available data. We discuss the functional characteristics required for a cell to be logically considered to be the normal counterpart of CLL B-cells. PMID:29670635

Microfluidic device to control interstitial flow-mediated homotypic and heterotypic cellular communication.

PubMed

Alonzo, Luis F; Moya, Monica L; Shirure, Venktesh S; George, Steven C

2015-09-07

Tissue engineering can potentially recreate in vivo cellular microenvironments in vitro for an array of applications such as biological inquiry and drug discovery. However, the majority of current in vitro systems still neglect many biological, chemical, and mechanical cues that are known to impact cellular functions such as proliferation, migration, and differentiation. To address this gap, we have developed a novel microfluidic device that precisely controls the spatial and temporal interactions between adjacent three-dimensional cellular environments. The device consists of four interconnected microtissue compartments (~0.1 mm(3)) arranged in a square. The top and bottom pairs of compartments can be sequentially loaded with discrete cellularized hydrogels creating the opportunity to investigate homotypic (left to right or x-direction) and heterotypic (top to bottom or y-direction) cell-cell communication. A controlled hydrostatic pressure difference across the tissue compartments in both x and y direction induces interstitial flow and modulates communication via soluble factors. To validate the biological significance of this novel platform, we examined the role of stromal cells in the process of vasculogenesis. Our device confirms previous observations that soluble mediators derived from normal human lung fibroblasts (NHLFs) are necessary to form a vascular network derived from endothelial colony forming cell-derived endothelial cells (ECFC-ECs). We conclude that this platform could be used to study important physiological and pathological processes that rely on homotypic and heterotypic cell-cell communication.

Aggregation of polyglutamine-expanded ataxin-3 sequesters its specific interacting partners into inclusions: Implication in a loss-of-function pathology

PubMed Central

Yang, Hui; Li, Jing-Jing; Liu, Shuai; Zhao, Jian; Jiang, Ya-Jun; Song, Ai-Xin; Hu, Hong-Yu

2014-01-01

Expansion of polyglutamine (polyQ) tract may cause protein misfolding and aggregation that lead to cytotoxicity and neurodegeneration, but the underlying mechanism remains to be elucidated. We applied ataxin-3 (Atx3), a polyQ tract-containing protein, as a model to study sequestration of normal cellular proteins. We found that the aggregates formed by polyQ-expanded Atx3 sequester its interacting partners, such as P97/VCP and ubiquitin conjugates, into the protein inclusions through specific interactions both in vitro and in cells. Moreover, this specific sequestration impairs the normal cellular function of P97 in down-regulating neddylation. However, expansion of polyQ tract in Atx3 does not alter the conformation of its surrounding regions and the interaction affinities with the interacting partners, although it indeed facilitates misfolding and aggregation of the Atx3 protein. Thus, we propose a loss-of-function pathology for polyQ diseases that sequestration of the cellular essential proteins via specific interactions into inclusions by the polyQ aggregates causes dysfunction of the corresponding proteins, and consequently leads to neurodegeneration. PMID:25231079

Endogenous sterol biosynthesis is important for mitochondrial function and cell morphology in procyclic forms of Trypanosoma brucei.

PubMed

Pérez-Moreno, Guiomar; Sealey-Cardona, Marco; Rodrigues-Poveda, Carlos; Gelb, Michael H; Ruiz-Pérez, Luis Miguel; Castillo-Acosta, Víctor; Urbina, Julio A; González-Pacanowska, Dolores

2012-10-01

Sterol biosynthesis inhibitors are promising entities for the treatment of trypanosomal diseases. Insect forms of Trypanosoma brucei, the causative agent of sleeping sickness, synthesize ergosterol and other 24-alkylated sterols, yet also incorporate cholesterol from the medium. While sterol function has been investigated by pharmacological manipulation of sterol biosynthesis, molecular mechanisms by which endogenous sterols influence cellular processes remain largely unknown in trypanosomes. Here we analyse by RNA interference, the effects of a perturbation of three specific steps of endogenous sterol biosynthesis in order to dissect the role of specific intermediates in proliferation, mitochondrial function and cellular morphology in procyclic cells. A decrease in the levels of squalene synthase and squalene epoxidase resulted in a depletion of cellular sterol intermediates and end products, impaired cell growth and led to aberrant morphologies, DNA fragmentation and a profound modification of mitochondrial structure and function. In contrast, cells deficient in sterol methyl transferase, the enzyme involved in 24-alkylation, exhibited a normal growth phenotype in spite of a complete abolition of the synthesis and content of 24-alkyl sterols. Thus, the data provided indicates that while the depletion of squalene and post-squalene endogenous sterol metabolites results in profound cellular defects, bulk 24-alkyl sterols are not strictly required to support growth in insect forms of T. brucei in vitro. Copyright © 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

TWO INNEXINS OF Spodoptera litura INFLUENCES HEMICHANNEL AND GAP JUNCTION FUNCTIONS IN CELLULAR IMMUNE RESPONSES.

PubMed

Pang, Zunyu; Li, Ming; Yu, Dongshuai; Yan, Zhang; Liu, Xinyi; Ji, Xinglai; Yang, Yang; Hu, Jiansheng; Luo, Kaijun

2015-09-01

Insect cellular immune responses include encapsulation, nodule formation, and phagocytosis. Hemichannels and gap junctions are involved in these cellular actions. Innexins (Inxs: analogous to the vertebrate connexins) form hemichannels and gap junctions, but the molecular mechanisms underlying their biology is still unclear. In this article, we reported a steady-state level of Inxs (SpliInxs) in hemocytes of Spodoptera litura, which formed nonfunctional hemichannels on the cell surface to maintain normal metabolism. We also reported that two innnexins (SpliInx2 and SpliInx3) were expressed significantly higher in hemocytes compared to other tissues, suggesting that they play important roles in hemocytes. Amino acid analysis found that two cysteine residues in two extracellular loops provided the capability for SpliInx2 and SpliInx3 hemichannels to dock into gap junctions. Western blotting demonstrated that both extracellular and intracellular loops of SpliInx3 and the extracellular loops of SpliInx2 might undergo posttranslational modification during the formation of a steady-state hemichannel. During hemichannel formation, SpliInx2 presented as one isoform, while SpliInx3 presented as three isoforms. These results provide fundamental knowledge for further study of how steady-state levels of SpliInxs are dynamically adjusted to perform cellular immune responses under immune challenge. © 2015 Wiley Periodicals, Inc.

Mold with improved core for metal casting operation

DOEpatents

Gritzner, Verne B.; Hackett, Donald W.

1977-01-01

The present invention is directed to a mold containing an improved core for use in casting hollow, metallic articles. The core is formed of, or covered with, a layer of cellular material which possesses sufficient strength to maintain its structural integrity during casting, but will crush to alleviate the internal stresses that build up if the normal contraction during solidification and cooling is restricted.

A novel microscopic method for analyzing Gram-stained vaginal smears in the diagnosis of disorders of vaginal microflora.

PubMed

Nenadić, Dane B; Pavlović, Miloš D; Motrenko, Tatjana

2015-08-01

The Nugent's score is still the gold standard in the great majority of studies dealing with the assessment of vaginal flora and the diagnosis of bacterial vaginosis (BV). The aim of this study was to show that the analysis of Gram-stained vaginal samples under microscope at the magnification of x200 (a novel microscopic method--NMM), as a fast and simple tool, easily applicable in everyday practice, better reflects complexity of vaginal microflora than the Nugent's methodology (x1000). Gram-stained vaginal smears from 394 asymptomatic pregnant women (24-28 week of pregnancy) were classified according to the Nugent's microscopic criteria (immersion, magnification x1000). The smears were then reexamined under immersion but at magnification x200. All samples were classified into 6 groups according to semiquanititative assessment of numbers (cellularity) and the ratio of rod (length < 1.5 microm) and small bacterial (< 1.5 microm) forms: hypercellular (normal full--NF), moderately cellular (normal mid-NM), hypocellular (normal empty--NE), bacterial vaginosis full (BVF), bacterial vaginosis mid (BVM), and bacterial vaginosis empty (BVE). Also yeasts, coccae, bifido and lepto bacterial forms as well polymorphonuclear (PMN) leukocytes were identified. According to the Nugent's scoring, BV was found in 78, intermediate findings in 63, and yeasts in 48 patients. By our criteria BV was confirmed in 88 patients (37 BVF, 24 BVM, and 27 BVN). Generally, both tools proved to be highly concordant for the diagnosis of BV (Lin's concordance correlation coefficient = 0.9852). In 40% of the women mixed flora was found: yeasts in 126 (32%), coccae in 145 (37%), bifido forms in 32 (8%) and lepto forms in 20 (5%). Almost a half of BV patients had also yeasts (39/88). Elevated PMN numbers were found in 102 (33%) patients with normal and in 36 (41%) women with BV. The newly described methodology is simpler to apply and much better reflects diversity of vaginal microflora. In this way it may be more valuable to molecular biologists and their attempts based on quantitative polymerase chain reaction (PCR) to define formulas for molecular diagnosis of bacterial vaginosis.

Unique activation of matrix metalloproteinase-9 within human liver metastasis from colorectal cancer.

PubMed Central

Zeng, Z. S.; Guillem, J. G.

1998-01-01

Experimental in vitro and animal data support an important role for matrix metalloproteinases (MMPs) in cancer invasion and metastasis via proteolytic degradation of the extracellular matrix (ECM). Our previous data have shown that MMP-9 mRNA is localized to the interface between liver metastasis and normal liver tissue, indicating that MMP-9 may play an important role in liver metastasis formation. In the present study, we analysed the cellular enzymatic expression of MMP-9 in 18 human colorectal cancer (CRC) liver metastasis specimens by enzyme-linked immunosorbent assay (ELISA) and zymography. ELISA analysis reveals that the latent form of MMP-9 is present in both liver metastasis and paired adjacent normal liver tissue. The mean level of the latent form of MMP-9 is 580+/-270 ng per mg total tissue protein (mean+/-s.e.) in liver metastasis vs 220+/-90 in normal liver tissue. However, this difference is not significantly different (P = 0.26). Using gelatin zymography, the 92-kDa band representative of the latent form is present in both liver metastasis and normal liver tissue. However, the 82 kDa band, representative of the active form of MMP-9, was seen only in liver metastasis. This was confirmed by Western blot analysis. Our observation of the unique presence of the active form of MMP-9 within liver metastasis suggests that proMMP-9 activation may be a pivotal event during CRC liver metastasis formation. Images Figure 3 Figure 4 PMID:9703281

Pulsating Hydrodynamic Instability in a Dynamic Model of Liquid-Propellant Combustion

NASA Technical Reports Server (NTRS)

Margolis, Stephen B.; Sacksteder, Kurt (Technical Monitor)

1999-01-01

Hydrodynamic (Landau) instability in combustion is typically associated with the onset of wrinkling of a flame surface, corresponding to the formation of steady cellular structures as the stability threshold is crossed. In the context of liquid-propellant combustion, such instability has recently been shown to occur for critical values of the pressure sensitivity of the burning rate and the disturbance wavenumber, significantly generalizing previous classical results for this problem that assumed a constant normal burning rate. Additionally, however, a pulsating form of hydrodynamic instability has been shown to occur as well, corresponding to the onset of temporal oscillations in the location of the liquid/gas interface. In the present work, we consider the realistic influence of a nonzero temperature sensitivity in the local burning rate on both types of stability thresholds. It is found that for sufficiently small values of this parameter, there exists a stable range of pressure sensitivities for steady, planar burning such that the classical cellular form of hydrodynamic instability and the more recent pulsating form of hydrodynamic instability can each occur as the corresponding stability threshold is crossed. For larger thermal sensitivities, however, the pulsating stability boundary evolves into a C-shaped curve in the disturbance-wavenumber/ pressure-sensitivity plane, indicating loss of stability to pulsating perturbations for all sufficiently large disturbance wavelengths. It is thus concluded, based on characteristic parameter values, that an equally likely form of hydrodynamic instability in liquid-propellant combustion is of a nonsteady, long-wave nature, distinct from the steady, cellular form originally predicted by Landau.

Pulsating Hydrodynamic Instability and Thermal Coupling in an Extended Landau/Levich Model of Liquid-Propellant Combustion. 1; Inviscid Analysis

NASA Technical Reports Server (NTRS)

Margolis, Stephen B.; Sacksteder, Kurt (Technical Monitor)

1999-01-01

Hydrodynamic (Landau) instability in combustion is typically associated with the onset of wrinkling of a flame surface, corresponding to the formation of steady cellular structures as the stability threshold is crossed. In the context of liquid-propellant combustion, such instability has recently been shown to occur for critical values of the pressure sensitivity of the burning rate and the disturbance wavenumber, significantly generalizing previous classical results for this problem that assumed a constant normal burning rate. Additionally, however, a pulsating form of hydrodynamic instability has been shown to occur as well, corresponding to the onset of temporal oscillations in the location of the liquid/gas interface. In the present work, we consider the realistic influence of a non-zero temperature sensitivity in the local burning rate on both types of stability thresholds. It is found that for sufficiently small values of this parameter, there exists a stable range of pressure sensitivities for steady, planar burning such that the classical cellular form of hydrodynamic instability and the more recent pulsating form of hydrodynamic instability can each occur as the corresponding stability threshold is crossed. For larger thermal sensitivities, however, the pulsating stability boundary evolves into a C-shaped curve in the (disturbance-wavenumber, pressure-sensitivity) plane, indicating loss of stability to pulsating perturbations for all sufficiently large disturbance wavelengths. It is thus concluded, based on characteristic parameter values, that an equally likely form of hydrodynamic instability in liquid-propellant combustion is of a non-steady, long-wave nature, distinct from the steady, cellular form originally predicted by Landau.

A Select Subset of Electron Transport Chain Genes Associated with Optic Atrophy Link Mitochondria to Axon Regeneration in Caenorhabditis elegans.

PubMed

Knowlton, Wendy M; Hubert, Thomas; Wu, Zilu; Chisholm, Andrew D; Jin, Yishi

2017-01-01

The role of mitochondria within injured neurons is an area of active interest since these organelles are vital for the production of cellular energy in the form of ATP. Using mechanosensory neurons of the nematode Caenorhabditis elegans to test regeneration after neuronal injury in vivo , we surveyed genes related to mitochondrial function for effects on axon regrowth after laser axotomy. Genes involved in mitochondrial transport, calcium uptake, mitophagy, or fission and fusion were largely dispensable for axon regrowth, with the exception of eat-3/Opa1 . Surprisingly, many genes encoding components of the electron transport chain were dispensable for regrowth, except for the iron-sulfur proteins gas-1, nduf-2.2, nduf-7 , and isp-1 , and the putative oxidoreductase rad-8 . In these mutants, axonal development was essentially normal and axons responded normally to injury by forming regenerative growth cones, but were impaired in subsequent axon extension. Overexpression of nduf-2.2 or isp-1 was sufficient to enhance regrowth, suggesting that mitochondrial function is rate-limiting in axon regeneration. Moreover, loss of function in isp-1 reduced the enhanced regeneration caused by either a gain-of-function mutation in the calcium channel EGL-19 or overexpression of the MAP kinase DLK-1. While the cellular function of RAD-8 remains unclear, our genetic analyses place rad-8 in the same pathway as other electron transport genes in axon regeneration. Unexpectedly, rad-8 regrowth defects were suppressed by altered function in the ubiquinone biosynthesis gene clk-1 . Furthermore, we found that inhibition of the mitochondrial unfolded protein response via deletion of atfs-1 suppressed the defective regrowth in nduf-2.2 mutants. Together, our data indicate that while axon regeneration is not significantly affected by general dysfunction of cellular respiration, it is sensitive to the proper functioning of a select subset of electron transport chain genes, or to the cellular adaptations used by neurons under conditions of injury.

A Select Subset of Electron Transport Chain Genes Associated with Optic Atrophy Link Mitochondria to Axon Regeneration in Caenorhabditis elegans

PubMed Central

Knowlton, Wendy M.; Hubert, Thomas; Wu, Zilu; Chisholm, Andrew D.; Jin, Yishi

2017-01-01

The role of mitochondria within injured neurons is an area of active interest since these organelles are vital for the production of cellular energy in the form of ATP. Using mechanosensory neurons of the nematode Caenorhabditis elegans to test regeneration after neuronal injury in vivo, we surveyed genes related to mitochondrial function for effects on axon regrowth after laser axotomy. Genes involved in mitochondrial transport, calcium uptake, mitophagy, or fission and fusion were largely dispensable for axon regrowth, with the exception of eat-3/Opa1. Surprisingly, many genes encoding components of the electron transport chain were dispensable for regrowth, except for the iron-sulfur proteins gas-1, nduf-2.2, nduf-7, and isp-1, and the putative oxidoreductase rad-8. In these mutants, axonal development was essentially normal and axons responded normally to injury by forming regenerative growth cones, but were impaired in subsequent axon extension. Overexpression of nduf-2.2 or isp-1 was sufficient to enhance regrowth, suggesting that mitochondrial function is rate-limiting in axon regeneration. Moreover, loss of function in isp-1 reduced the enhanced regeneration caused by either a gain-of-function mutation in the calcium channel EGL-19 or overexpression of the MAP kinase DLK-1. While the cellular function of RAD-8 remains unclear, our genetic analyses place rad-8 in the same pathway as other electron transport genes in axon regeneration. Unexpectedly, rad-8 regrowth defects were suppressed by altered function in the ubiquinone biosynthesis gene clk-1. Furthermore, we found that inhibition of the mitochondrial unfolded protein response via deletion of atfs-1 suppressed the defective regrowth in nduf-2.2 mutants. Together, our data indicate that while axon regeneration is not significantly affected by general dysfunction of cellular respiration, it is sensitive to the proper functioning of a select subset of electron transport chain genes, or to the cellular adaptations used by neurons under conditions of injury. PMID:28539870

Non-transferrin bound iron: a key role in iron overload and iron toxicity.

PubMed

Brissot, Pierre; Ropert, Martine; Le Lan, Caroline; Loréal, Olivier

2012-03-01

Besides transferrin iron, which represents the normal form of circulating iron, non-transferrin bound iron (NTBI) has been identified in the plasma of patients with various pathological conditions in which transferrin saturation is significantly elevated. To show that: i) NTBI is present not only during chronic iron overload disorders (hemochromatosis, transfusional iron overload) but also in miscellaneous diseases which are not primarily iron overloaded conditions; ii) this iron species represents a potentially toxic iron form due to its high propensity to induce reactive oxygen species and is responsible for cellular damage not only at the plasma membrane level but also towards different intracellular organelles; iii) the NTBI concept may be expanded to include intracytosolic iron forms which are not linked to ferritin, the major storage protein which exerts, at the cellular level, the same type of protective effect towards the intracellular environment as transferrin in the plasma. Plasma NTBI and especially labile plasma iron determinations represent a new important biological tool since elimination of this toxic iron species is a major therapeutic goal. The NTBI approach represents an important mechanistic concept for explaining cellular iron excess and toxicity and provides new important biochemical diagnostic tools. This article is part of a Special Issue entitled Transferrins: Molecular mechanisms of iron transport and disorders. Copyright © 2011 Elsevier B.V. All rights reserved.

Could inhibition of the proteasome cause mad cow disease?

PubMed

Hooper, Nigel M

2003-04-01

The proteasome is the cellular machinery responsible for the degradation of normal and misfolded proteins. Inhibitors of the proteasome are being evaluated as therapeutic agents and recent work suggests that such inhibition might promote the neurotoxic properties of the prion protein (the causative agent of mad cow disease) and its conformational conversion to the infectious form, thus raising the question as to whether proteasome inhibitors might facilitate the development of prion diseases.

Unique spatial and cellular expression patterns of Hoxa5, Hoxb4 and Hoxb6 proteins in normal developing murine lung are modified in pulmonary hypoplasia

PubMed Central

Volpe, MaryAnn Vitoria; Wang, Karen Ting Wai; Nielsen, Heber Carl; Chinoy, Mala Romeshchandra

2009-01-01

Background Hox transcription factors modulate signaling pathways controlling organ morphogenesis and maintain cell fate and differentiation in adults. Retinoid signaling, key in regulating Hox expression, is altered in pulmonary hypoplasia. Information on pattern-specific expression of Hox proteins in normal lung development and in pulmonary hypoplasia is minimal. Our objective was to determine how pulmonary hypoplasia alters temporal, spatial and cellular expression of Hoxa5, Hoxb4 and Hoxb6 proteins compared to normal lung development. Methods Temporal, spatial and cellular Hoxa5, Hoxb4 and Hoxb6 expression was studied in normal (untreated) and nitrofen-induced hypoplastic (NT-PH) lungs from gestational day 13.5, 16, 19 fetuses and neonates using western blot and immunohistochemistry. Results Modification of protein levels and spatial and cellular Hox expression patterns in NT-PH lungs was consistent with delayed lung development. Distinct protein isoforms were detected for each Hox protein. Expression levels of the Hoxa5 and Hoxb6 isoforms changed with development and further in NT-PH lungs. Compared to normal lungs, Gd19 and neonatal NT-PH lungs had decreased Hoxb6 and increased Hoxa5 and Hoxb4. Hoxa5 cellular localization changed from mesenchyme to epithelia earlier in normal lungs. Hoxb4 was expressed in mesenchyme and epithelial cells throughout development. Hoxb6 remained mainly in mesenchymal cells around distal airways. Conclusions Unique spatial and cellular expression of Hoxa5, Hoxb4 and Hoxb6 participates in branching morphogenesis and terminal sac formation. Altered Hox protein temporal and cellular balance of expression either contributes to pulmonary hypoplasia or functions as a compensatory mechanism attempting to correct abnormal lung development and maturation in this condition. PMID:18553509

Effects of ozone in normal human epidermal keratinocytes.

PubMed

McCarthy, James T; Pelle, Edward; Dong, Kelly; Brahmbhatt, Krupa; Yarosh, Dan; Pernodet, Nadine

2013-05-01

Ozone is a tropospheric pollutant that can form at ground level as a result of an interaction between sunlight and hydrocarbon engine emissions. As ozone is an extremely oxidative reaction product, epidermal cells are in the outer layer of defense against ozone. We exposed normal human epidermal keratinocytes (NHEK) to concentrations of ozone that have been measured in cities and assayed for its effects. Hydrogen peroxide and IL-1α levels both increased while ATP levels decreased. We found a decrease in the NAD-dependent histone deacetylase, sirtuin 3. Lastly, we found that ozone increased DNA damage as evaluated by Comet assay. Taken together, our results show increased damage to NHEK that will ultimately impair normal cellular function as a result of an environmentally relevant ozone exposure. © 2013 John Wiley & Sons A/S.

The cellular responses of the rat to an intraperitoneal inoculation of Nippostrongylus brasiliensis larvae

PubMed Central

Greenberg, Z.; Wertheim, Guta

1973-01-01

The cellular responses to intraperitoneal inoculation of infective (L3) or non-infective (L2) larvae of Nippostrongylus brasiliensis were studied in unprimed rats. Peritoneal macrophages adhered to the larvae immediately after inoculation and the coated larvae became attached to the omentum. As additional inflammatory cells, appearing in the peritoneal exudate, adhered to the larvae, nodules were formed which with time organized into granulomas. The initial response was not specific and consisted of an intense neutrophilia which developed in all rats a few hours after inoculation and lasted 24 hours. Thereafter the cellular responses were distinctly different in the case of each larval stage. In rats receiving L3 larvae an intense eosinophilia in the peritoneal exudate began to develop 7 days after inoculation, and islands of numerous pyroninophilic blast- and plasma cells were present at the periphery of the granuloma. The L3 larvae survived in the granulomas for 7–10 days. The granulomas formed around the L2 larvae consisted mainly of macrophages; the number of eosinophils did not rise above normal and there were no pyroninophilic cells. The L2 larvae survived in the granuloma for 3 days. In control rats, in which an intestinal infection was established by subcutaneous administration of larvae, no changes were detected in the cellular composition of the peritoneal exudate. The significance of these responses is discussed in relation to recent reports about the cellular composition of antigenic and non-antigenic granulomas. ImagesFIG. 3FIG. 4FIG. 5FIG. 6FIG. 7FIG. 8FIG. 9FIG. 10 PMID:4705618

Atomic force microscopy studies on cellular elastic and viscoelastic properties.

PubMed

Li, Mi; Liu, Lianqing; Xi, Ning; Wang, Yuechao

2018-01-01

In this work, a method based on atomic force microscopy (AFM) approach-reside-retract experiments was established to simultaneously quantify the elastic and viscoelastic properties of single cells. First, the elastic and viscoelastic properties of normal breast cells and cancerous breast cells were measured, showing significant differences in Young's modulus and relaxation times between normal and cancerous breast cells. Remarkable differences in cellular topography between normal and cancerous breast cells were also revealed by AFM imaging. Next, the elastic and viscoelasitc properties of three other types of cell lines and primary normal B lymphocytes were measured; results demonstrated the potential of cellular viscoelastic properties in complementing cellular Young's modulus for discerning different states of cells. This research provides a novel way to quantify the mechanical properties of cells by AFM, which allows investigation of the biomechanical behaviors of single cells from multiple aspects.

From the Cover: Disease-Induced Disparities in Formation of the Nanoparticle-Biocorona and the Toxicological Consequences

PubMed Central

Shannahan, Jonathan H.; Fritz, Kristofer S.; Raghavendra, Achyut J.; Podila, Ramakrishna; Persaud, Indushekar; Brown, Jared M.

2016-01-01

Nanoparticle (NP) association with macromolecules in a physiological environment forms a biocorona (BC), which alters NP distribution, activity, and toxicity. While BC formation is dependent on NP physicochemical properties, little information exists on the influence of the physiological environment. Obese individuals and those with cardiovascular disease exist with altered serum chemistry, which is expected to influence BC formation and NP toxicity. We hypothesize that a BC formed on NPs following incubation in hyperlipidemic serum will result in altered NP–BC protein content, cellular association, and toxicity compared to normal serum conditions. We utilized Fe3O4 NPs, which are being developed as MRI contrast and tumor targeting agents to test our hypothesis. We used rat aortic endothelial cells (RAECs) within a dynamic flow in vitro exposure system to more accurately depict the in vivo environment. A BC was formed on 20nm PVP-suspended Fe3O4 NPs following incubation in water, 10% normal or hyperlipidemic rat serum. Addition of BCs resulted in increased hydrodynamic size and decreased surface charge. More cholesterol associated with Fe3O4 NPs after incubation in hyperlipidemic as compared with normal serum. Using quantitative proteomics, we identified unique differences in BC protein components between the 2 serum types. Under flow conditions, formation of a BC from both serum types reduced RAECs association of Fe3O4 NPs. Addition of BCs was found to exacerbate RAECs inflammatory gene responses to Fe3O4 NPs (Fe3O4-hyperlipidemic > Fe3O4-normal > Fe3O4) including increased expression of IL-6, TNF-α, Cxcl-2, VCAM-1, and ICAM-1. Overall, these findings demonstrate that disease-induced variations in physiological environments have a significant impact NP-BC formation, cellular association, and cell response. PMID:27255384

Heart failure: when form fails to follow function.

PubMed

Katz, Arnold M; Rolett, Ellis L

2016-02-01

Cardiac performance is normally determined by architectural, cellular, and molecular structures that determine the heart's form, and by physiological and biochemical mechanisms that regulate the function of these structures. Impaired adaptation of form to function in failing hearts contributes to two syndromes initially called systolic heart failure (SHF) and diastolic heart failure (DHF). In SHF, characterized by high end-diastolic volume (EDV), the left ventricle (LV) cannot eject a normal stroke volume (SV); in DHF, with normal or low EDV, the LV cannot accept a normal venous return. These syndromes are now generally defined in terms of ejection fraction (EF): SHF became 'heart failure with reduced ejection fraction' (HFrEF) while DHF became 'heart failure with normal or preserved ejection fraction' (HFnEF or HFpEF). However, EF is a chimeric index because it is the ratio between SV--which measures function, and EDV--which measures form. In SHF the LV dilates when sarcomere addition in series increases cardiac myocyte length, whereas sarcomere addition in parallel can cause concentric hypertrophy in DHF by increasing myocyte thickness. Although dilatation in SHF allows the LV to accept a greater venous return, it increases the energy cost of ejection and initiates a vicious cycle that contributes to progressive dilatation. In contrast, concentric hypertrophy in DHF facilitates ejection but impairs filling and can cause heart muscle to deteriorate. Differences in the molecular signals that initiate dilatation and concentric hypertrophy can explain why many drugs that improve prognosis in SHF have little if any benefit in DHF. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Ecological comparison of cellular stress responses among populations - normalizing RT-qPCR values to investigate differential environmental adaptations.

PubMed

Koenigstein, Stefan; Pöhlmann, Kevin; Held, Christoph; Abele, Doris

2013-05-16

Rising temperatures and other environmental factors influenced by global climate change can cause increased physiological stress for many species and lead to range shifts or regional population extinctions. To advance the understanding of species' response to change and establish links between individual and ecosystem adaptations, physiological reactions have to be compared between populations living in different environments. Although changes in expression of stress genes are relatively easy to quantify, methods for reliable comparison of the data remain a contentious issue. Using normalization algorithms and further methodological considerations, we compare cellular stress response gene expression levels measured by RT-qPCR after air exposure experiments among different subpopulations of three species of the intertidal limpet Nacella. Reference gene assessment algorithms reveal that stable reference genes can differ among investigated populations and / or treatment groups. Normalized expression values point to differential defense strategies to air exposure in the investigated populations, which either employ a pronounced cellular stress response in the inducible Hsp70 forms, or exhibit a comparatively high constitutive expression of Hsps (heat shock proteins) while showing only little response in terms of Hsp induction. This study serves as a case study to explore the methodological prerequisites of physiological stress response comparisons among ecologically and phylogenetically different organisms. To improve the reliability of gene expression data and compare the stress responses of subpopulations under potential genetic divergence, reference gene stability algorithms are valuable and necessary tools. As the Hsp70 isoforms have been shown to play different roles in the acute stress responses and increased constitutive defenses of populations in their different habitats, these comparative studies can yield insight into physiological strategies of adaptation to environmental stress and provide hints for the prudent use of the cellular stress response as a biomarker to study environmental stress and stress adaptation of populations under changing environmental conditions.

Ecological comparison of cellular stress responses among populations – normalizing RT-qPCR values to investigate differential environmental adaptations

PubMed Central

2013-01-01

Background Rising temperatures and other environmental factors influenced by global climate change can cause increased physiological stress for many species and lead to range shifts or regional population extinctions. To advance the understanding of species’ response to change and establish links between individual and ecosystem adaptations, physiological reactions have to be compared between populations living in different environments. Although changes in expression of stress genes are relatively easy to quantify, methods for reliable comparison of the data remain a contentious issue. Using normalization algorithms and further methodological considerations, we compare cellular stress response gene expression levels measured by RT-qPCR after air exposure experiments among different subpopulations of three species of the intertidal limpet Nacella. Results Reference gene assessment algorithms reveal that stable reference genes can differ among investigated populations and / or treatment groups. Normalized expression values point to differential defense strategies to air exposure in the investigated populations, which either employ a pronounced cellular stress response in the inducible Hsp70 forms, or exhibit a comparatively high constitutive expression of Hsps (heat shock proteins) while showing only little response in terms of Hsp induction. Conclusions This study serves as a case study to explore the methodological prerequisites of physiological stress response comparisons among ecologically and phylogenetically different organisms. To improve the reliability of gene expression data and compare the stress responses of subpopulations under potential genetic divergence, reference gene stability algorithms are valuable and necessary tools. As the Hsp70 isoforms have been shown to play different roles in the acute stress responses and increased constitutive defenses of populations in their different habitats, these comparative studies can yield insight into physiological strategies of adaptation to environmental stress and provide hints for the prudent use of the cellular stress response as a biomarker to study environmental stress and stress adaptation of populations under changing environmental conditions. PMID:23680017

Sub-cellular force microscopy in single normal and cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babahosseini, H.; Carmichael, B.; Strobl, J.S.

2015-08-07

This work investigates the biomechanical properties of sub-cellular structures of breast cells using atomic force microscopy (AFM). The cells are modeled as a triple-layered structure where the Generalized Maxwell model is applied to experimental data from AFM stress-relaxation tests to extract the elastic modulus, the apparent viscosity, and the relaxation time of sub-cellular structures. The triple-layered modeling results allow for determination and comparison of the biomechanical properties of the three major sub-cellular structures between normal and cancerous cells: the up plasma membrane/actin cortex, the mid cytoplasm/nucleus, and the low nuclear/integrin sub-domains. The results reveal that the sub-domains become stiffer andmore » significantly more viscous with depth, regardless of cell type. In addition, there is a decreasing trend in the average elastic modulus and apparent viscosity of the all corresponding sub-cellular structures from normal to cancerous cells, which becomes most remarkable in the deeper sub-domain. The presented modeling in this work constitutes a unique AFM-based experimental framework to study the biomechanics of sub-cellular structures. - Highlights: • The cells are modeled as a triple-layered structure using Generalized Maxwell model. • The sub-domains include membrane/cortex, cytoplasm/nucleus, and nuclear/integrin. • Biomechanics of corresponding sub-domains are compared among normal and cancer cells. • Viscoelasticity of sub-domains show a decreasing trend from normal to cancer cells. • The decreasing trend becomes most significant in the deeper sub-domain.« less

Centrobin-mediated Regulation of the Centrosomal Protein 4.1-associated Protein (CPAP) Level Limits Centriole Length during Elongation Stage*

PubMed Central

Gudi, Radhika; Haycraft, Courtney J.; Bell, P. Darwin; Li, Zihai; Vasu, Chenthamarakshan

2015-01-01

Microtubule-based centrioles in the centrosome mediate accurate bipolar cell division, spindle orientation, and primary cilia formation. Cellular checkpoints ensure that the centrioles duplicate only once in every cell cycle and achieve precise dimensions, dysregulation of which results in genetic instability and neuro- and ciliopathies. The normal cellular level of centrosomal protein 4.1-associated protein (CPAP), achieved by its degradation at mitosis, is considered as one of the major mechanisms that limits centriole growth at a predetermined length. Here we show that CPAP levels and centriole elongation are regulated by centrobin. Exogenous expression of centrobin causes abnormal elongation of centrioles due to massive accumulation of CPAP in the cell. Conversely, CPAP was undetectable in centrobin-depleted cells, suggesting that it undergoes degradation in the absence of centrobin. Only the reintroduction of full-length centrobin, but not its mutant form that lacks the CPAP binding site, could restore cellular CPAP levels in centrobin-depleted cells, indicating that persistence of CPAP requires its interaction with centrobin. Interestingly, inhibition of the proteasome in centrobin-depleted cells restored the cellular and centriolar CPAP expression, suggesting its ubiquitination and proteasome-mediated degradation when centrobin is absent. Intriguingly, however, centrobin-overexpressing cells also showed proteasome-independent accumulation of ubiquitinated CPAP and abnormal, ubiquitin-positive, elongated centrioles. Overall, our results show that centrobin interacts with ubiquitinated CPAP and prevents its degradation for normal centriole elongation function. Therefore, it appears that loss of centrobin expression destabilizes CPAP and triggers its degradation to restrict the centriole length during biogenesis. PMID:25616662

Expression of hemidesmosomal and extracellular matrix proteins by normal and malignant human prostate tissue.

PubMed Central

Nagle, R. B.; Hao, J.; Knox, J. D.; Dalkin, B. L.; Clark, V.; Cress, A. E.

1995-01-01

The progression of prostate carcinoma may be influenced by the biochemical nature of the basal lamina surrounding the primary carcinoma cells. As a first step toward understanding this process, the composition and structure of the basal lamina in normal prostate, prostatic intraepithelial neoplasia, and human carcinoma were determined. In addition, a comparison was made between the attachments of the normal basal cell to its underlying basal lamina and those made by primary prostate carcinoma. The normal basal cells form both focal adhesions and hemidesmosomal-like structures as observed by transmission electron microscopy. The normal basal cells exhibited a polarized distribution of hemidesmosomal associated proteins including BP180, BP230, HD1, plectin, laminin-gamma 2(B2t), collagen VII, and the corresponding integrin laminin receptors alpha 6 beta 1 and alpha 6 beta 4. The expression and distribution pattern of these proteins were retained in the prostate intraepithelial neoplasia lesions. In contrast, the carcinoma cells uniformly lacked hemidesmosomal structures, the integrin alpha 6 beta 4, BP180, laminin-gamma 2 (B2t), and collagen VII but did express BP230 (30%), plectin, HD1 (15%), and the integrin laminin receptors alpha 3 beta 1 and alpha 6 beta 1. These results suggest that, although a detectable basal lamina structure is present in carcinoma, its composition and cellular attachments are abnormal. The loss of critical cellular attachments may play a role in influencing the progression potential of prostate carcinoma. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:7778688

Cellular processing of gold nanoparticles: CE-ICP-MS evidence for the speciation changes in human cytosol.

PubMed

Legat, Joanna; Matczuk, Magdalena; Timerbaev, Andrei R; Jarosz, Maciej

2018-01-01

The cellular uptake of gold nanoparticles (AuNPs) may (or may not) affect their speciation, but information on the chemical forms in which the particles exist in the cell remains obscure. An analytical method based on the use of capillary electrophoresis hyphenated with inductively coupled plasma mass spectrometry (ICP-MS) has been proposed to shed light on the intracellular processing of AuNPs. It was observed that when being introduced into normal cytosol, the conjugates of 10-50 nm AuNPs with albumin evolved in human serum stayed intact. On the contrary, under simulated cancer cytosol conditions, the nanoconjugates underwent decomposition, the rate of which and the resulting metal speciation patterns were strongly influenced by particle size. The new peaks that appeared in ICP-MS electropherograms could be ascribed to nanosized species, as upon ultracentrifugation, they quantitatively precipitated whereas the supernatant showed only trace Au signals. Our present study is the first step to unravel a mystery of the cellular chemistry for metal-based nanomedicines.

Inhibition of AMPK catabolic action by GSK3

PubMed Central

Suzuki, Tsukasa; Bridges, Dave; Nakada, Daisuke; Skiniotis, Georgios; Morrison, Sean J.; Lin, Jiandie; Saltiel, Alan R.; Inoki, Ken

2013-01-01

SUMMARY AMP-activated protein kinase (AMPK) regulates cellular energy homeostasis by inhibiting anabolic and activating catabolic processes. While AMPK activation has been extensively studied, mechanisms that inhibit AMPK remain elusive. Here we report that glycogen synthase kinase 3 (GSK3) inhibits AMPK function. GSK3 forms a stable complex with AMPK through interactions with the AMPK β regulatory subunit and phosphorylates the AMPK α catalytic subunit. This phosphorylation enhances the accessibility of the activation loop of the α subunit to phosphatases, thereby inhibiting AMPK kinase activity. Surprisingly, PI3K-Akt signaling, which is a major anabolic signaling and normally inhibits GSK3 activity, promotes GSK3 phosphorylation and inhibition of AMPK, thus revealing how AMPK senses anabolic environments in addition to cellular energy levels. Consistently, disrupting GSK3 function within the AMPK complex sustains higher AMPK activity and cellular catabolic processes even under anabolic conditions, indicating that GSK3 acts as a critical sensor for anabolic signaling to regulate AMPK. PMID:23623684

Genetic and cellular mechanisms of the formation of Esophageal Atresia and Tracheoesophageal Fistula

PubMed Central

Jacobs, Ian J.; Que, Jianwen

2015-01-01

Foregut separation involves dynamic changes in the activities of signaling pathways and transcription factors. Recent mouse genetic studies demonstrate that some of these pathways interact with each other to form a complex network, leading to a unique dorsal-ventral patterning in the early foregut. In this review we will discuss how this unique dorsal-ventral patterning is set prior to the foregut separation and how disruption of this patterning affects the separation process. We will further discuss the roles of downstream targets of these pathways in regulating separation at cellular and molecular levels. Understanding the mechanism of normal separation process will provide us insights into the pathobiology of a relatively common birth defect Esophageal Atresia (EA) with/without Tracheo-esophageal Fistula (TEF). PMID:23679023

Correlating two-photon excited fluorescence imaging of breast cancer cellular redox state with seahorse flux analysis of normalized cellular oxygen consumption

NASA Astrophysics Data System (ADS)

Hou, Jue; Wright, Heather J.; Chan, Nicole; Tran, Richard; Razorenova, Olga V.; Potma, Eric O.; Tromberg, Bruce J.

2016-06-01

Two-photon excited fluorescence (TPEF) imaging of the cellular cofactors nicotinamide adenine dinucleotide and oxidized flavin adenine dinucleotide is widely used to measure cellular metabolism, both in normal and pathological cells and tissues. When dual-wavelength excitation is used, ratiometric TPEF imaging of the intrinsic cofactor fluorescence provides a metabolic index of cells-the "optical redox ratio" (ORR). With increased interest in understanding and controlling cellular metabolism in cancer, there is a need to evaluate the performance of ORR in malignant cells. We compare TPEF metabolic imaging with seahorse flux analysis of cellular oxygen consumption in two different breast cancer cell lines (MCF-7 and MDA-MB-231). We monitor metabolic index in living cells under both normal culture conditions and, for MCF-7, in response to cell respiration inhibitors and uncouplers. We observe a significant correlation between the TPEF-derived ORR and the flux analyzer measurements (R=0.7901, p<0.001). Our results confirm that the ORR is a valid dynamic index of cell metabolism under a range of oxygen consumption conditions relevant for cancer imaging.

Sub-cellular force microscopy in single normal and cancer cells.

PubMed

Babahosseini, H; Carmichael, B; Strobl, J S; Mahmoodi, S N; Agah, M

2015-08-07

This work investigates the biomechanical properties of sub-cellular structures of breast cells using atomic force microscopy (AFM). The cells are modeled as a triple-layered structure where the Generalized Maxwell model is applied to experimental data from AFM stress-relaxation tests to extract the elastic modulus, the apparent viscosity, and the relaxation time of sub-cellular structures. The triple-layered modeling results allow for determination and comparison of the biomechanical properties of the three major sub-cellular structures between normal and cancerous cells: the up plasma membrane/actin cortex, the mid cytoplasm/nucleus, and the low nuclear/integrin sub-domains. The results reveal that the sub-domains become stiffer and significantly more viscous with depth, regardless of cell type. In addition, there is a decreasing trend in the average elastic modulus and apparent viscosity of the all corresponding sub-cellular structures from normal to cancerous cells, which becomes most remarkable in the deeper sub-domain. The presented modeling in this work constitutes a unique AFM-based experimental framework to study the biomechanics of sub-cellular structures. Copyright © 2015 Elsevier Inc. All rights reserved.

Thermal experience during embryogenesis contributes to the induction of dwarfism in whitefish Coregonus lavaretus.

PubMed

Steinbacher, Peter; Wanzenböck, Josef; Brandauer, Magdalena; Holper, Raphael; Landertshammer, Jasmin; Mayr, Magdalena; Platzl, Christian; Stoiber, Walter

2017-01-01

Ecotype pairs provide well-suited model systems for study of intraspecific phenotypical diversification of animals. However, little is still known about the processes that account for the development of different forms and sizes within a species, particularly in teleosts. Here, embryos of a normal-growing 'large' form and a dwarf form of whitefish Coregonus lavaretus were incubated at two temperatures that are usually experienced at their own spawning sites (2°C for the normal and 6°C for the dwarf form). All fish were subjected to similar thermal treatment after hatching. The present data demonstrate for the first time that different thermal experience in embryonic life has lasting effects on body and muscle growth of this ecotype pair and contributes to the development of the dwarf form. Thus, juvenile fish of the regular form are much smaller and have less muscle mass when pre-hatching thermal conditions were similar to those typical for the spawning sites of the dwarf form (6°C) than when subjected to conditions of their own spawning sites (2°C). Surprisingly, fish of the dwarf form exhibit a similar pattern of response to thermal history (2°-fish much larger than 6°-fish), indicating that in their case, normal spawning site temperature (6°C) is indeed likely to act as a growth limiting factor. Results also demonstrate that the hypertrophic and hyperplastic muscle growth modes are similarly affected by thermal history. Immunolabelling experiments for Pax7, H3P and Mef2 provide evidence that the cellular mechanisms behind the increased growth rates after cold incubation in both ecotypes are increased proliferation and reduced differentiation rates of muscle precursor cells. This is of major significance to aspects of ecological and developmental biology and from the evolutionary perspective.

[Morphological characteristics of cornea in patients with vernal keratoconjunctivitis by in vivo laser scanning confocal microscopy].

PubMed

Le, Qi-hua; Hong, Jia-xu; Zhu, Wen-qing; Sun, Xing-huai; Xu, Jian-jiang

2011-05-01

To explore the morphological characteristics on cornea in patients with vernal keratoconjunctivitis (VKC) by the application of in vivo laser scanning confocal microscopy (LSCM). The experimental design was retrospective observation case series (case control study). Twenty-six patients, each diagnosed as bilateral VKC, were enrolled in the study, among which 13 were tarsal form, 5 were bulbar form and the rest were mixed form. Nine patients had the clinical course less than one year, eight subjects longer than three years, and the rest between them. Another twenty-six healthy volunteers with matching age and gender were selected as normal control. All participants had their right eyes examined with the in vivo confocal microscopy (HRT II/RCM). Central cornea and superior peripheral cornea were chosen as the examination points. The images were recorded automatically and cellular density of each layer was analyzed by installed software. Software ImageJ was utilized to analyze the density, diameter, branch number and tortuosity of subbasal nerve fiber in VKC patients. Independent t test was performed to assess the differences on cellular density between VKC patients and normal control, as well as those between central and peripheral cornea in VKC patients. Fisher chi-square test was used to compare the infiltration rate of Langerhans cells in corneal epithelium between VKC patients and controls. ANOVA was applied to assess the differences in cellular density among three subtypes, as well as among different duration of VKC. Independent t-test and chi-square test were applied to analyze the parameters of subbasal nerve fiber. The morphological changes in cornea included the absence of superficial hyperreflective polygonal epithelial cells, infiltration of Langerhans cells in and(or) underneath corneal epithelium and activation of keratocytes in anterior stroma. Corneal epithelium conjunctivalization and stromal neovascularization could be identified in patients with corneal neovascular epithelium. Longitudinal or oblique dark striae could be found in the posterior stroma in patients with complicated keratoconus. The density of epithelial cells at central and peripheral cornea in healthy controls were (6033.1 ± 998.7) cells/mm(2) and (6098.4 ± 298.3) cells/mm(2), while that in VKC patients were (5972.2 ± 1148.2) cells/mm(2) and (6178.5 ± 318.9) cells/mm(2) respectively, the differences being no statistical significant between them (t = 1.191, 1.011; P = 0.238, 0.318). However, it's found in VKC patients that cellular density at peripheral cornea was significantly higher than that at central area (t = 2.249, P = 0.03). The density of anterior stromal cells at central and peripheral cornea in healthy controls was (1001.4 ± 125.3) cells/mm(2) and (924.6 ± 201.4) cells/mm(2), while that in VKC patients was (1184.5 ± 115.3) cells/mm(2) and (1101.4 ± 151.1) cells/mm(2), the difference bearing no statistical significance (t = 6.617, 3.439; P = 0.001). The density of posterior stromal cells in normal subjects and VKC patients was (537.7 ± 42.6) cells/mm(2) and (548.7 ± 79.8) cells/mm(2), that of endothelial cells was (2985.7 ± 401.2) cells/mm(2) and (3021.5 ± 383.3) cells/mm(2), respectively, neither difference had statistical significance (t = 0.174, 1.112; P = 0.864, 0.282). Langerhans cell infiltration could be identified in 61.5% (16 cases) VKC patients, which was significantly higher than normal control (2 cases, 7.7%) (χ(2) = 12.49, P = 0.001). Furthermore, much intense Langerhans cells infiltration was found in bulbar form and mix form than tarsal form. (t = 6.617, P = 0.001). The density and diameter of subbasal nerve fiber in VKC patients decreased significantly than those in normal subjects, whereas the tortuosity increased significantly. The morphological changes of cornea in VKC patients mainly involve corneal epithelium, subbasal nerve fiber and anterior stroma. In vivo LSCM is helpful in discriminating the subtypes of VKC.

Progress toward clonable inorganic nanoparticles

NASA Astrophysics Data System (ADS)

Ni, Thomas W.; Staicu, Lucian C.; Nemeth, Richard S.; Schwartz, Cindi L.; Crawford, David; Seligman, Jeffrey D.; Hunter, William J.; Pilon-Smits, Elizabeth A. H.; Ackerson, Christopher J.

2015-10-01

Pseudomonas moraviensis stanleyae was recently isolated from the roots of the selenium (Se) hyperaccumulator plant Stanleya pinnata. This bacterium tolerates normally lethal concentrations of SeO32- in liquid culture, where it also produces Se nanoparticles. Structure and cellular ultrastructure of the Se nanoparticles as determined by cellular electron tomography shows the nanoparticles as intracellular, of narrow dispersity, symmetrically irregular and without any observable membrane or structured protein shell. Protein mass spectrometry of a fractionated soluble cytosolic material with selenite reducing capability identified nitrite reductase and glutathione reductase homologues as NADPH dependent candidate enzymes for the reduction of selenite to zerovalent Se nanoparticles. In vitro experiments with commercially sourced glutathione reductase revealed that the enzyme can reduce SeO32- (selenite) to Se nanoparticles in an NADPH-dependent process. The disappearance of the enzyme as determined by protein assay during nanoparticle formation suggests that glutathione reductase is associated with or possibly entombed in the nanoparticles whose formation it catalyzes. Chemically dissolving the nanoparticles releases the enzyme. The size of the nanoparticles varies with SeO32- concentration, varying in size form 5 nm diameter when formed at 1.0 μM [SeO32-] to 50 nm maximum diameter when formed at 100 μM [SeO32-]. In aggregate, we suggest that glutathione reductase possesses the key attributes of a clonable nanoparticle system: ion reduction, nanoparticle retention and size control of the nanoparticle at the enzyme site.Pseudomonas moraviensis stanleyae was recently isolated from the roots of the selenium (Se) hyperaccumulator plant Stanleya pinnata. This bacterium tolerates normally lethal concentrations of SeO32- in liquid culture, where it also produces Se nanoparticles. Structure and cellular ultrastructure of the Se nanoparticles as determined by cellular electron tomography shows the nanoparticles as intracellular, of narrow dispersity, symmetrically irregular and without any observable membrane or structured protein shell. Protein mass spectrometry of a fractionated soluble cytosolic material with selenite reducing capability identified nitrite reductase and glutathione reductase homologues as NADPH dependent candidate enzymes for the reduction of selenite to zerovalent Se nanoparticles. In vitro experiments with commercially sourced glutathione reductase revealed that the enzyme can reduce SeO32- (selenite) to Se nanoparticles in an NADPH-dependent process. The disappearance of the enzyme as determined by protein assay during nanoparticle formation suggests that glutathione reductase is associated with or possibly entombed in the nanoparticles whose formation it catalyzes. Chemically dissolving the nanoparticles releases the enzyme. The size of the nanoparticles varies with SeO32- concentration, varying in size form 5 nm diameter when formed at 1.0 μM [SeO32-] to 50 nm maximum diameter when formed at 100 μM [SeO32-]. In aggregate, we suggest that glutathione reductase possesses the key attributes of a clonable nanoparticle system: ion reduction, nanoparticle retention and size control of the nanoparticle at the enzyme site. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04097c

Russell body inducing threshold depends on the variable domain sequences of individual human IgG clones and the cellular protein homeostasis.

PubMed

Stoops, Janelle; Byrd, Samantha; Hasegawa, Haruki

2012-10-01

Russell bodies are intracellular aggregates of immunoglobulins. Although the mechanism of Russell body biogenesis has been extensively studied by using truncated mutant heavy chains, the importance of the variable domain sequences in this process and in immunoglobulin biosynthesis remains largely unknown. Using a panel of structurally and functionally normal human immunoglobulin Gs, we show that individual immunoglobulin G clones possess distinctive Russell body inducing propensities that can surface differently under normal and abnormal cellular conditions. Russell body inducing predisposition unique to each immunoglobulin G clone was corroborated by the intrinsic physicochemical properties encoded in the heavy chain variable domain/light chain variable domain sequence combinations that define each immunoglobulin G clone. While the sequence based intrinsic factors predispose certain immunoglobulin G clones to be more prone to induce Russell bodies, extrinsic factors such as stressful cell culture conditions also play roles in unmasking Russell body propensity from immunoglobulin G clones that are normally refractory to developing Russell bodies. By taking advantage of heterologous expression systems, we dissected the roles of individual subunit chains in Russell body formation and examined the effect of non-cognate subunit chain pair co-expression on Russell body forming propensity. The results suggest that the properties embedded in the variable domain of individual light chain clones and their compatibility with the partnering heavy chain variable domain sequences underscore the efficiency of immunoglobulin G biosynthesis, the threshold for Russell body induction, and the level of immunoglobulin G secretion. We propose that an interplay between the unique properties encoded in variable domain sequences and the state of protein homeostasis determines whether an immunoglobulin G expressing cell will develop the Russell body phenotype in a dynamic cellular setting. Copyright © 2012 Elsevier B.V. All rights reserved.

Confocal Microscopy and Molecular-Specific Optical Contrast Agents for the Detection of Oral Neoplasia

PubMed Central

Carlson, Alicia L.; Gillenwater, Ann M.; Williams, Michelle D.; El-Naggar, Adel K.; Richards-Kortum, R. R.

2009-01-01

Using current clinical diagnostic techniques, it is difficult to visualize tumor morphology and architecture at the cellular level, which is necessary for diagnostic localization of pathologic lesions. Optical imaging techniques have the potential to address this clinical need by providing real-time, sub-cellular resolution images. This paper describes the use of dual mode confocal microscopy and optical molecular-specific contrast agents to image tissue architecture, cellular morphology, and sub-cellular molecular features of normal and neoplastic oral tissues. Fresh tissue slices were prepared from 33 biopsies of clinically normal and abnormal oral mucosa obtained from 14 patients. Reflectance confocal images were acquired after the application of 6% acetic acid, and fluorescence confocal images were acquired after the application of a fluorescence contrast agent targeting the epidermal growth factor receptor (EGFR). The dual imaging modes provided images similar to light microscopy of hematoxylin and eosin and immunohistochemistry staining, but from thick fresh tissue slices. Reflectance images provided information on the architecture of the tissue and the cellular morphology. The nuclear-to-cytoplasmic (N/C) ratio from the reflectance images was at least 7.5 times greater for the carcinoma than the corresponding normal samples, except for one case of highly keratinized carcinoma. Separation of carcinoma from normal and mild dysplasia was achieved using this ratio (p<0.01). Fluorescence images of EGFR expression yielded a mean fluorescence labeling intensity (FLI) that was at least 2.7 times higher for severe dysplasia and carcinoma samples than for the corresponding normal sample, and could be used to distinguish carcinoma from normal and mild dysplasia (p<0.01). Analyzed together, the N/C ratio and the mean FLI may improve the ability to distinguish carcinoma from normal squamous epithelium. PMID:17877424

Abnormalities in the cellular phase of blood fibrinolytic activity in systemic lupus erythematosus and in venous thromboembolism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moroz, L.A.; MacLean, L.D.; Langleben, D.

1986-09-15

Fibrinolytic activities of whole blood and plasma were determined by /sup 125/I-fibrin radiometric assay in 16 normal subjects, and in 11 patients with systemic lupus erythematosus (SLE), 14 with progressive systemic sclerosis (PSS), 23 with venous thromboembolic disease, and 20 patients awaiting elective surgery. Mean whole blood and plasma activities for patients with PSS, and for those awaiting elective surgery, were similar to normal values, as was the mean plasma activity in patients with SLE. However, mean whole blood activity in SLE was significantly decreased compared with normals (p less than 0.05), with mean plasma activity accounting for 44% ofmore » mean whole blood activity (compared with 17% in normal subjects), representing a 67% decrease in mean calculated cellular phase activity in SLE, when compared with normals. Since the numbers of cells (neutrophils, monocytes) possibly involved in cellular activity were not decreased, the findings suggest a functional defect in fibrinolytic activity of one or more blood cell types in SLE. An additional finding was the participation of the cellular phase as well as the well-known plasma phase of blood in the fibrinolytic response to thromboembolism.« less

The role of metals in carcinogenesis: biochemistry and metabolism.

PubMed Central

Jennette, K W

1981-01-01

The oxyanions of vanadium, chromium, molybdenum, arsenic, and selenium are stable forms of these elements in high oxidation states which cross cell membranes using the normal phosphate and/or sulfate transport systems of the cell. Once inside the cell, these oxyanions may sulfuryl transfer reactions. Often the oxyanions serve as alternate enzyme substrates but form ester products which are hydrolytically unstable compared with the sulfate and phosphate esters and, therefore, decompose readily in aqueous solution. Arsenite and selenite are capable of reacting with sulfhydryl groups in proteins. Some cells are able to metabolize redox active oxyanions to forms of the elements in other stable oxidation states. Specific enzymes may be involved in the metabolic processes. The metabolites of these elements may form complexes with small molecules, proteins and nucleic acids which inhibit their ability to function properly. The divalent ions of beryllium, manganese, cobalt, nickel, cadmium, mercury, and lead are stable forms of these elements which may mimic essential divalent ions such as magnesium, calcium, iron, copper, or zinc. These ions may complex small molecules, enzymes, and nucleic acids in such a way that the normal activity of these species is altered. Free radicals may be produced in the presence of these metal ions which damage critical cellular molecules. PMID:7023933

Variant forms of ataxia telangiectasia.

PubMed Central

Taylor, A M; Flude, E; Laher, B; Stacey, M; McKay, E; Watt, J; Green, S H; Harding, A E

1987-01-01

Two ataxia telangiectasia patients with unusual clinical and cellular features are described. Cultured fibroblasts and PHA stimulated lymphocytes from these two patients showed a smaller increase of radiosensitivity than cells from other A-T patients, as measured by colony forming ability or induced chromosome damage respectively, after exposure to ionising radiation. The response of DNA synthesis to irradiation of these cells was, however, the same as for other A-T patients. Cells from a third patient with some clinical features of A-T but with a very protracted course also showed low levels of radiation induced chromosome damage, but colony forming ability and the response of DNA synthesis after irradiation were no different from cells of normal subjects. There was, however, an increased level of translocations and unstable chromosomal rearrangements in this patient's lymphocytes. Images PMID:3430541

Determination of the cellular retinoic-acid-binding protein in dysplastic epithelia of the cervix uteri, differentiated into apo and holo forms.

PubMed

Volz-Köster, S; Volz, J; Kiefer, A; Biesalski, H K

2000-01-01

The appearance of the cervical mucosa is regulated by different factors including retinoic acid. Hormone-dependent alteration of the cervix uteri mucosa is accompanied by a decrease or increase of cytoplasmatic retinoic-acid-binding protein (CRABP). To elucidate whether this hormone-dependent alteration of CRABP is preserved in the case of neoplasms of the cervix uteri, we measured the level of total and apo-CRABP in normal and neoplastically transformed cervical cells. In a prospective pilot study, standardised biopsies of normal epithelium and cervical intra-epithelial neoplasm grade 3 (CIN III) were taken from 24 patients. A newly developed method was used to determine the intra-epithelial level of apo- and total CRABP. The concentration of total CRABP in normal squamous epithelium compared with that in intra-epithelial neoplasm grade 3 is very significantly lower in the CIN III areas (normal: 3.66 +/- 1.46 pmol/ mg wet weight +/- SD; CIN III 1.43 +/- 0.59 pmol/mg P < 0.01). In addition CRABP in the apo form is lower in normal than in neoplastic epithelium (Wilcoxon test for paired non-parametric values: P < 0.05; mean for all patients: normal: 1.65 + 0.82 pmol/mg; CIN III: 1.14 +/- 0.23 pmol/mg). From our results we conclude that, in neoplastically transformed cells, the hormone-dependent CRABP cycle is interrupted. Whether this has consequences for the further development of the neoplastic cells has to be elucidated.

A Highly Toxic Cellular Prion Protein Induces a Novel, Nonapoptotic Form of Neuronal Death

PubMed Central

Christensen, Heather M.; Dikranian, Krikor; Li, Aimin; Baysac, Kathleen C.; Walls, Ken C.; Olney, John W.; Roth, Kevin A.; Harris, David A.

2010-01-01

Several different deletions within the N-terminal tail of the prion protein (PrP) induce massive neuronal death when expressed in transgenic mice. This toxicity is dose-dependently suppressed by coexpression of full-length PrP, suggesting that it results from subversion of a normal physiological activity of cellular PrP. We performed a combined biochemical and morphological analysis of Tg(ΔCR) mice, which express PrP carrying a 21-aa deletion (residues 105-125) within a highly conserved region of the protein. Death of cerebellar granule neurons in Tg(ΔCR) mice is not accompanied by activation of either caspase-3 or caspase-8 or by increased levels of the autophagy marker, LC3-II. In electron micrographs, degenerating granule neurons displayed a unique morphology characterized by heterogeneous condensation of the nuclear matrix without formation of discrete chromatin masses typical of neuronal apoptosis. Our data demonstrate that perturbations in PrP functional activity induce a novel, nonapoptotic, nonautophagic form of neuronal death whose morphological features are reminiscent of those associated with excitotoxic stress. PMID:20472884

Transcriptional response of dermal fibroblasts in direct current electric fields.

PubMed

Jennings, Jessica; Chen, Dongquan; Feldman, Dale

2008-07-01

During the course of normal wound healing, fibroblasts at the wound edge are exposed to electric fields (EFs) ranging from 40 to 200 mV/mm. Various forms of EFs influence fibroblast migration, proliferation, and protein synthesis. Thus, EFs may contribute to fibroblast activation during wound repair. To elucidate the role of EFs during the normal progression of healing, this study compares gene expression in normal adult dermal fibroblasts exposed to a 100 mV/mm EF for 1 h to non-stimulated controls. Significantly increased expression of 162 transcripts and decreased expression of 302 transcripts was detected using microarrays, with 126 transcripts above the level of 1.4-fold increases or decreases compared to the controls. Above the level of twofold, only 11 genes were significantly increased or decreased compared to controls. Many of these significantly regulated genes are associated with wound repair through the processes of matrix production, cellular signaling, and growth. Activity within specific cellular signaling pathways is noted, including TGF-beta, G-proteins, and inhibition of apoptosis. In addition, RT-PCR analysis of the expression of KLF6, FN1, RGS2, and JMJD1C over continued stimulation and at different field strengths suggests that there are specific windows of field characteristics for maximum induction of these genes. EFs thus appear to have an important role in controlling fibroblast activity in the process of wound healing.

Fuzzy cellular automata models in immunology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, E.

1996-10-01

The self-nonself character of antigens is considered to be fuzzy. The Chowdhury et al. cellular automata model is generalized accordingly. New steady states are found. The first corresponds to a below-normal help and suppression and is proposed to be related to autoimmune diseases. The second corresponds to a below-normal B-cell level.

Role of cellular oxalate in oxalate clearance of patients with calcium oxalate monohydrate stone formation and normal controls.

PubMed

Oehlschläger, Sven; Fuessel, Susanne; Meye, Axel; Herrmann, Jana; Froehner, Michael; Albrecht, Steffen; Wirth, Manfred P

2009-03-01

To examine the cellular, plasma, and urinary oxalate and erythrocyte oxalate flux in patients with calcium oxalate monohydrate (COM) stone formation vs normal controls. Pathologic oxalate clearance in humans is mostly integrated in calcium oxalate stone formation. An underlying cause of deficient oxalate clearance could be defective transmembrane oxalate transport, which, in many tissues, is regulated by an anion exchanger (SLC26). We studied 2 groups: 40 normal controls and 41 patients with COM stone formation. Red blood cells were divided for cellular oxalate measurement and for resuspension in a buffered solution (pH 7.40); 0.1 mmol/L oxalate was added. The supernatant was measured for oxalate immediately and 1 hour after incubation. The plasma and urinary oxalate were analyzed in parallel. The mean cellular oxalate concentrations were significantly greater in the normal controls (5.25 +/- 0.47 micromol/L) than in those with COM stone formation (2.36 +/- 0.28 micromol/L; P < .01). The mean urinary oxalate concentrations were significantly greater in those with COM stone formation (0.31 +/- 0.02 mmol/L) than in the controls (0.24 +/- 0.02 mmol/L; P < .01). The cellular oxalate concentrations correlated significantly with the plasma (r = 0.49-0.63; P < .01) and urinary oxalate (r = -0.29-0.41; P < .03) concentrations in both groups. The plasma oxalate concentrations correlated significantly with the urinary oxalate concentrations (r = -0.30; P < .03) in the controls and with the erythrocyte oxalate flux (r = 0.25; P < .05) in those with COM stone formation. Our data implicate the presence of a cellular oxalate buffer to stabilize plasma and urinary oxalate concentrations in normal controls.

Lithium-induced developmental anomalies in the spirotrich ciliate Stylonychia lemnae (Ciliophora, Hypotrichida).

PubMed

Makhija, Seema; Gupta, Renu; Toteja, Ravi

2015-08-01

Lithium is known to have profound biological effects of varying intensity in different life forms. In the present investigation, the effect of lithium was studied on the spirotrich ciliate Stylonychia lemnae. Lithium treatment brings about quantitative changes in the patterning of ciliary structures in S. lemnae. The dorsal surface of the affected cells develops supernumerary ciliary kineties due to excessive proliferation of the kinetosomes. The ventral surface on the other hand develops fewer than normal cirri formed from reduced numbers of ciliary primordia. The adoral zone of membranelles (AZM) fails to remodel properly as, in certain segments, membranelles become disarranged and misaligned. Lithium-induced changes are transitory as the normal pattern is restored during recovery after the cells are shifted to normal medium, suggesting non-genic regulation of cortical pattern. Lithium also affects the process of cell proliferation as the number of cells undergoing division is negligible as compared to reorganizing cells. The results point to the extremely complex and heterogeneous organization of the cellular cortex (plasma membrane and cytoskeleton) which is capable of exerting autonomous control over the phenotype and cortical pattern. Copyright © 2015 Elsevier GmbH. All rights reserved.

Gene expression profiling in the Cynomolgus macaque Macaca fascicularis shows variation within the normal birth range

PubMed Central

2011-01-01

Background Although an adverse early-life environment has been linked to an increased risk of developing the metabolic syndrome, the molecular mechanisms underlying altered disease susceptibility as well as their relevance to humans are largely unknown. Importantly, emerging evidence suggests that these effects operate within the normal range of birth weights and involve mechanisms of developmental palsticity rather than pathology. Method To explore this further, we utilised a non-human primate model Macaca fascicularis (Cynomolgus macaque) which shares with humans the same progressive history of the metabolic syndrome. Using microarray we compared tissues from neonates in the average birth weight (50-75th centile) to those of lower birth weight (5-25th centile) and studied the effect of different growth trajectories within the normal range on gene expression levels in the umbilical cord, neonatal liver and skeletal muscle. Results We identified 1973 genes which were differentially expressed in the three tissue types between average and low birth weight animals (P < 0.05). Gene ontology analysis identified that these genes were involved in metabolic processes including cellular lipid metabolism, cellular biosynthesis, cellular macromolecule synthesis, cellular nitrogen metabolism, cellular carbohydrate metabolism, cellular catabolism, nucleotide and nucleic acid metabolism, regulation of molecular functions, biological adhesion and development. Conclusion These differences in gene expression levels between animals in the upper and lower percentiles of the normal birth weight range may point towards early life metabolic adaptations that in later life result in differences in disease risk. PMID:21999700

Morphological effects of chronic bilateral phrenectomy or vagotomy in the fetal lamb lung.

PubMed Central

Alcorn, D; Adamson, T M; Maloney, J E; Robinson, P M

1980-01-01

The relationship between fetal espiratory activity and fetal lung development has been studied at the cellular level using two experimental models. Chronic bilateral phrenectomy over a period of 20-28 days during the last trimester of the fetal lamb resulted in hypoplastic lungs, although cellular maturity, as indicated by the presence of alveolar epithelial Type II cells, was present. In the lungs from fetal lambs undergoing sham operations for a similar time course there was evidence of enhanced alveolar proliferation when compared with lungs from normal fetal sheep of a similar gastational age, most probably as a result of operative stress. Following chronic bilateral vagotomy no changes in size or histology of the fetal lamb lungs were detected. At an ultrastructural level, however, inclusions of Type II cells consistently showed the loss of the typical osmiophilic lamellated appearance. These results indicate the importance of the fetal breathing apparatus in maintaining a volume of lung liquid which is adequate for normal pulmonary development, particularly during the phase in which alveoli are formed. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 PMID:7429961

The antiproliferative aspects of mortalin (review).

PubMed

Wadhwa, R; Mitsui, Y; Ide, T; Kaul, S

1995-07-01

Cellular mortal and immortal phenotypes as defined by the limited and the infinite capacity of cells to divide are the characteristics of normal and cancerous cells in culture. Numerous strategies that have been employed to understand the mechanism(s) of normal as well as tumor cell growth have revealed that these are genetically controlled, however, the genes and the synchronized regulations remain largely undefined so far. The present report reviews the identification of mortalin, a novel member of murine hsp70 family of proteins, as a gene involved in pathways that determine divisional phenotype of cells in vitro. In the present study, the anti-proliferative activity of mortalin is demonstrated also in human skin fibroblasts (TIG-73PD) by microinjection of anti-mortalin antibody. Furthermore, studies on the mortalin immunofluorescence patterns in SV40-immortalized pre-crisis and post-crisis human cells have revealed that the change in the intracellular distribution of mortalin is linked to the change in the divisional phenotype of cells. Thus, the studies to resolve the molecular basis of association of the cytosolically distributed form of mortalin with cellular mortal phenotype would be important in understanding of the mechanism(s) that determine replicative potential of cells in culture.

Cellular, synaptic and biochemical features of resilient cognition in Alzheimer’s disease

PubMed Central

Arnold, Steven. E.; Louneva, Natalia; Cao, Kajia; Wang, Li-San; Han, Li-Ying; Wolk, David A.; Negash, Selamawit; Leurgans, Sue E.; Schneider, Julie A.; Buchman, Aron S.; Wilson, Robert S.; Bennett, David A.

2012-01-01

While neuritic plaques and neurofibrillary tangles in older adults are correlated with cognitive impairment and severity of dementia, it has long been recognized that the relationship is imperfect as some people exhibit normal cognition despite high levels of AD pathology. We compared the cellular, synaptic and biochemical composition of midfrontal cortices in female subjects from the Religious Orders Study who were stratified into three subgroups: 1) pathological AD with normal cognition (“AD-Resilient”), 2) pathological AD with AD-typical dementia (“AD-Dementia)” and 3) pathologically normal with normal cognition (“Normal Comparison”). The AD-Resilient group exhibited preserved densities of synaptophysin-labeled presynaptic terminals and synaptopodin-labeled dendritic spines compared to the AD-Dementia group, and increased densities of GFAP astrocytes compared to both the AD-Dementia and Normal Comparison group. Further, in a discovery antibody microarray protein analysis we identified a number of candidate protein abnormalities that were associated with diagnostic group. These data characterize cellular and synaptic features and identify novel biochemical targets that may be associated with resilient cognitive brain aging in the setting of pathological AD. PMID:22554416

Morphometric computer-assisted image analysis of epithelial cells in different grades of oral squamous cell carcinoma.

PubMed

Ananjan, Chatterjee; Jyothi, Mahadesh; Laxmidevi, B L; Gopinathan, Pillai Arun; Nazir, Salroo Humaira; Pradeep, L

2018-01-01

Oral squamous cell carcinoma (OSCC) accounts 94% of all malignant lesions in the oral cavity. In the assessment of OSCC, nowadays the WHO grading system has been followed widely but due to its subjectivity, investigators applied the sophisticated technique of computer-assisted image analysis in the grading of carcinoma in larynx, lungs, esophagus, and cervix to make it more objective. Access, analyze, and compare the cellular area (CA); cytoplasmic area (Cyt A); nuclear area (NA); nuclear perimeter (NP); nuclear form factor (NF); and nuclear-cytoplasmic ratio (N/C) of the cells in different grades of OSCC. Fifty OSCC cases were obtained and stained with hematoxylin and eosin which were graded according to the WHO classification. The sections were subjected to morphometric analysis to analyze all the morphometric parameters in different grades of OSCC and subjected to one-way ANOVA statistical analysis. CA and Cyt A decreased from normal mucosa with dedifferentiation of OSCC. The NA and NP increased in carcinoma group when compared to normal mucosa but decreased with dedifferentiation of OSCC (P < 0.05). NF had no significance with normal mucosa and different grades of OSCC (P > 0.05), while N/C ratio increased from normal mucosa through increasing grades of OSCC, reaching the highest value in poorly differentiated squamous cell carcinoma (P < 0.05). Both cellular and nuclear variables provide a more accurate indication of tumor aggressiveness than any single parameter. Morphometric analysis can be a reliable tool to determine objectively the degree of malignancy at the invasive tumor front.

Label-free high-throughput imaging flow cytometry

NASA Astrophysics Data System (ADS)

Mahjoubfar, A.; Chen, C.; Niazi, K. R.; Rabizadeh, S.; Jalali, B.

2014-03-01

Flow cytometry is an optical method for studying cells based on their individual physical and chemical characteristics. It is widely used in clinical diagnosis, medical research, and biotechnology for analysis of blood cells and other cells in suspension. Conventional flow cytometers aim a laser beam at a stream of cells and measure the elastic scattering of light at forward and side angles. They also perform single-point measurements of fluorescent emissions from labeled cells. However, many reagents used in cell labeling reduce cellular viability or change the behavior of the target cells through the activation of undesired cellular processes or inhibition of normal cellular activity. Therefore, labeled cells are not completely representative of their unaltered form nor are they fully reliable for downstream studies. To remove the requirement of cell labeling in flow cytometry, while still meeting the classification sensitivity and specificity goals, measurement of additional biophysical parameters is essential. Here, we introduce an interferometric imaging flow cytometer based on the world's fastest continuous-time camera. Our system simultaneously measures cellular size, scattering, and protein concentration as supplementary biophysical parameters for label-free cell classification. It exploits the wide bandwidth of ultrafast laser pulses to perform blur-free quantitative phase and intensity imaging at flow speeds as high as 10 meters per second and achieves nanometer-scale optical path length resolution for precise measurements of cellular protein concentration.

Cellular Automata Generalized To An Inferential System

NASA Astrophysics Data System (ADS)

Blower, David J.

2007-11-01

Stephen Wolfram popularized elementary one-dimensional cellular automata in his book, A New Kind of Science. Among many remarkable things, he proved that one of these cellular automata was a Universal Turing Machine. Such cellular automata can be interpreted in a different way by viewing them within the context of the formal manipulation rules from probability theory. Bayes's Theorem is the most famous of such formal rules. As a prelude, we recapitulate Jaynes's presentation of how probability theory generalizes classical logic using modus ponens as the canonical example. We emphasize the important conceptual standing of Boolean Algebra for the formal rules of probability manipulation and give an alternative demonstration augmenting and complementing Jaynes's derivation. We show the complementary roles played in arguments of this kind by Bayes's Theorem and joint probability tables. A good explanation for all of this is afforded by the expansion of any particular logic function via the disjunctive normal form (DNF). The DNF expansion is a useful heuristic emphasized in this exposition because such expansions point out where relevant 0s should be placed in the joint probability tables for logic functions involving any number of variables. It then becomes a straightforward exercise to rely on Boolean Algebra, Bayes's Theorem, and joint probability tables in extrapolating to Wolfram's cellular automata. Cellular automata are seen as purely deductive systems, just like classical logic, which probability theory is then able to generalize. Thus, any uncertainties which we might like to introduce into the discussion about cellular automata are handled with ease via the familiar inferential path. Most importantly, the difficult problem of predicting what cellular automata will do in the far future is treated like any inferential prediction problem.

Surface-anchored poly(acryloyl-L(D)-valine) with enhanced chirality-selective effect on cellular uptake of gold nanoparticles

PubMed Central

Deng, Jun; Wu, Sai; Yao, Mengyun; Gao, Changyou

2016-01-01

Chirality is one of the ubiquitous phenomena in biological systems. The left handed (L-) amino acids and right handed (D-) sugars are normally found in proteins, and in RNAs and DNAs, respectively. The effect of chiral surfaces at the nanoscale on cellular uptake has, however, not been explored. This study reveals for the first time the molecular chirality on gold nanoparticles (AuNPs) functions as a direct regulator for cellular uptake. Monolayers of 2-mercaptoacetyl-L(D)-valine (L(D)-MAV) and poly(acryloyl-L(D)-valine (L(D)-PAV) chiral molecules were formed on AuNPs surface, respectively. The internalized amount of PAV-AuNPs was several times larger than that of MAV-AuNPs by A549 and HepG2 cells, regardless of the chirality difference. However, the D-PAV-AuNPs were internalized with significantly larger amount than the L-PAV-AuNPs. This chirality-dependent uptake effect is likely attributed to the preferable interaction between the L-phospholipid-based cell membrane and the D-enantiomers. PMID:27531648

Oxidative Stress, Redox Regulation and Diseases of Cellular Differentiation

PubMed Central

Ye, Zhi-Wei; Zhang, Jie; Townsend, Danyelle M.; Tew, Kenneth D.

2015-01-01

Background Within cells, there is a narrow concentration threshold that governs whether reactive oxygen species (ROS) induce toxicity or act as second messengers. Scope of review We discuss current understanding of how ROS arise, facilitate cell signaling, cause toxicities and disease related to abnormal cell differentiation and those (primarily) sulfur based pathways that provide nucleophilicity to offset these effects. Primary conclusions Cellular redox homeostasis mediates a plethora of cellular pathways that determine life and death events. For example, ROS intersect with GSH based enzyme pathways to influence cell differentiation, a process integral to normal hematopoiesis, but also affecting a number of diverse cell differentiation related human diseases. Recent attempts to manage such pathologies have focused on intervening in some of these pathways, with the consequence that differentiation therapy targeting redox homeostasis has provided a platform for drug discovery and development. General Significance The balance between electrophilic oxidative stress and protective biomolecular nucleophiles predisposes the evolution of modern life forms. Imbalances of the two can produce aberrant redox homeostasis with resultant pathologies. Understanding the pathways involved provides opportunities to consider interventional strategies. PMID:25445706

Surface-anchored poly(acryloyl-L(D)-valine) with enhanced chirality-selective effect on cellular uptake of gold nanoparticles

NASA Astrophysics Data System (ADS)

Deng, Jun; Wu, Sai; Yao, Mengyun; Gao, Changyou

2016-08-01

Chirality is one of the ubiquitous phenomena in biological systems. The left handed (L-) amino acids and right handed (D-) sugars are normally found in proteins, and in RNAs and DNAs, respectively. The effect of chiral surfaces at the nanoscale on cellular uptake has, however, not been explored. This study reveals for the first time the molecular chirality on gold nanoparticles (AuNPs) functions as a direct regulator for cellular uptake. Monolayers of 2-mercaptoacetyl-L(D)-valine (L(D)-MAV) and poly(acryloyl-L(D)-valine (L(D)-PAV) chiral molecules were formed on AuNPs surface, respectively. The internalized amount of PAV-AuNPs was several times larger than that of MAV-AuNPs by A549 and HepG2 cells, regardless of the chirality difference. However, the D-PAV-AuNPs were internalized with significantly larger amount than the L-PAV-AuNPs. This chirality-dependent uptake effect is likely attributed to the preferable interaction between the L-phospholipid-based cell membrane and the D-enantiomers.

Surface-anchored poly(acryloyl-L(D)-valine) with enhanced chirality-selective effect on cellular uptake of gold nanoparticles.

PubMed

Deng, Jun; Wu, Sai; Yao, Mengyun; Gao, Changyou

2016-08-17

Chirality is one of the ubiquitous phenomena in biological systems. The left handed (L-) amino acids and right handed (D-) sugars are normally found in proteins, and in RNAs and DNAs, respectively. The effect of chiral surfaces at the nanoscale on cellular uptake has, however, not been explored. This study reveals for the first time the molecular chirality on gold nanoparticles (AuNPs) functions as a direct regulator for cellular uptake. Monolayers of 2-mercaptoacetyl-L(D)-valine (L(D)-MAV) and poly(acryloyl-L(D)-valine (L(D)-PAV) chiral molecules were formed on AuNPs surface, respectively. The internalized amount of PAV-AuNPs was several times larger than that of MAV-AuNPs by A549 and HepG2 cells, regardless of the chirality difference. However, the D-PAV-AuNPs were internalized with significantly larger amount than the L-PAV-AuNPs. This chirality-dependent uptake effect is likely attributed to the preferable interaction between the L-phospholipid-based cell membrane and the D-enantiomers.

Plasma and cellular fibronectin: distinct and independent functions during tissue repair

PubMed Central

2011-01-01

Fibronectin (FN) is a ubiquitous extracellular matrix (ECM) glycoprotein that plays vital roles during tissue repair. The plasma form of FN circulates in the blood, and upon tissue injury, is incorporated into fibrin clots to exert effects on platelet function and to mediate hemostasis. Cellular FN is then synthesized and assembled by cells as they migrate into the clot to reconstitute damaged tissue. The assembly of FN into a complex three-dimensional matrix during physiological repair plays a key role not only as a structural scaffold, but also as a regulator of cell function during this stage of tissue repair. FN fibrillogenesis is a complex, stepwise process that is strictly regulated by a multitude of factors. During fibrosis, there is excessive deposition of ECM, of which FN is one of the major components. Aberrant FN-matrix assembly is a major contributing factor to the switch from normal tissue repair to misregulated fibrosis. Understanding the mechanisms involved in FN assembly and how these interplay with cellular, fibrotic and immune responses may reveal targets for the future development of therapies to regulate aberrant tissue-repair processes. PMID:21923916

Rational Design of Cancer-Targeted Benzoselenadiazole by RGD Peptide Functionalization for Cancer Theranostics.

PubMed

Yang, Liye; Li, Wenying; Huang, Yanyu; Zhou, Yangliang; Chen, Tianfeng

2015-09-01

A cancer-targeted conjugate of the selenadiazole derivative BSeC (benzo[1,2,5] selenadiazole-5-carboxylic acid) with RGD peptide as targeting molecule and PEI (polyethylenimine) as a linker is rationally designed and synthesized in the present study. The results show that RGD-PEI-BSeC forms nanoparticles in aqueous solution with a core-shell nanostructure and high stability under physiological conditions. This rational design effectively enhances the selective cellular uptake and cellular retention of BSeC in human glioma cells, and increases its selectivity between cancer and normal cells. The nanoparticles enter the cells through receptor-mediated endocytosis via clathrin-mediated and nystatin-dependent lipid raft-mediated pathways. Internalized nanoparticles trigger glioma cell apoptosis by activation of ROS-mediated p53 phosphorylation. Therefore, this study provides a strategy for the rational design of selenium-containing cancer-targeted theranostics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cellular repressor of E1A-stimulated genes is a bona fide lysosomal protein which undergoes proteolytic maturation during its biosynthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schaehs, Philipp; Weidinger, Petra; Probst, Olivia C.

2008-10-01

Cellular repressor of E1A-stimulated genes (CREG) has been reported to be a secretory glycoprotein implicated in cellular growth and differentiation. We now show that CREG is predominantly localized within intracellular compartments. Intracellular CREG was found to lack an N-terminal peptide present in the secreted form of the protein. In contrast to normal cells, CREG is largely secreted by fibroblasts missing both mannose 6-phosphate receptors. This is not observed in cells lacking only one of them. Mass spectrometric analysis of recombinant CREG revealed that the protein contains phosphorylated oligosaccharides at either of its two N-glycosylation sites. Cellular CREG was found tomore » cosediment with lysosomal markers upon subcellular fractionation by density-gradient centrifugation. In fibroblasts expressing a CREG-GFP fusion construct, the heterologous protein was detected in compartments containing lysosomal proteins. Immunolocalization of endogenous CREG confirmed that intracellular CREG is localized in lysosomes. Proteolytic processing of intracellular CREG involves the action of lysosomal cysteine proteinases. These results establish that CREG is a lysosomal protein that undergoes proteolytic maturation in the course of its biosynthesis, carries the mannose 6-phosphate recognition marker and depends on the interaction with mannose 6-phosphate receptors for efficient delivery to lysosomes.« less

Expression of genomic AtCYCD2;1 in Arabidopsis induces cell division at smaller cell sizes: implications for the control of plant growth.

PubMed

Qi, Ruhu; John, Peter Crook Lloyd

2007-07-01

The Arabidopsis (Arabidopsis thaliana) CYCD2;1 gene introduced in genomic form increased cell formation in the Arabidopsis root apex and leaf, while generating full-length mRNA, raised CDK/CYCLIN enzyme activity, reduced G1-phase duration, and reduced size of cells at S phase and division. Other cell cycle genes, CDKA;1, CYCLIN B;1, and the cDNA form of CYCD2;1 that produced an aberrantly spliced mRNA, produced smaller or zero increases in CDK/CYCLIN activity and did not increase the number of cells formed. Plants with a homozygous single insert of genomic CYCD2;1 grew with normal morphology and without accelerated growth of root or shoot, not providing evidence that cell formation or CYCLIN D2 controls growth of postembryonic vegetative tissues. At the root apex, cells progressed normally from meristem to elongation, but their smaller size enclosed less growth and a 40% reduction in final size of epidermal and cortical cells was seen. Smaller elongated cell size inhibited endoreduplication, indicating a cell size requirement. Leaf cells were also smaller and more numerous during proliferation and epidermal pavement and palisade cells attained 59% and 69% of controls, whereas laminas reached normal size. Autonomous control of expansion was therefore not evident in abundant cell types that formed tissues of root or leaf. Cell size was reduced by a greater number formed in a tissue prior to cell and tissue expansion. Initiation and termination of expansion did not correlate with cell dimension or number and may be determined by tissue-wide signals acting across cellular boundaries.

Selective inhibition of MG-63 osteosarcoma cell proliferation induced by curcumin-loaded self-assembled arginine-rich-RGD nanospheres.

PubMed

Chang, Run; Sun, Linlin; Webster, Thomas J

2015-01-01

Osteosarcoma is the most frequent primary malignant form of bone cancer, comprising 30% of all bone cancer cases. The objective of this in vitro study was to develop a treatment against osteosarcoma with higher selectivity toward osteosarcoma cells and lower cytotoxicity toward normal healthy osteoblast cells. Curcumin (or diferuloylmethane) has been found to have antioxidant and anticancer effects by multiple cellular pathways. However, it has lower water solubility and a higher degradation rate in alkaline conditions. In this study, the amphiphilic peptide C18GR7RGDS was used as a curcumin carrier in aqueous solution. This peptide contains a hydrophobic aliphatic tail group leading to their self-assembly by hydrophobic interactions, as well as a hydrophilic head group composed of an arginine-rich and an arginine-glycine-aspartic acid structure. Through characterization by transmission electron microscopy, self-assembled structures of spherical amphiphilic nanoparticles (APNPs) with diameters of 10-20 nm in water and phosphate-buffered saline were observed, but this structure dissociated when the pH value was reduced to 4. Using a method of codissolution with acetic acid and dialysis tubing, the solubility of curcumin was enhanced and a homogeneous solution was formed in the presence of APNPs. Successful encapsulation of curcumin in APNPs was then confirmed by Fourier transform infrared and X-ray diffraction analyses. The cytotoxicity and cellular uptake of the APNP/curcumin complexes on both osteosarcoma and normal osteoblast cell lines were also evaluated by methyl-thiazolyl-tetrazolium assays and confocal fluorescence microscopy. The results showed that the curcumin-loaded APNPs had significant selective cytotoxicity against MG-63 osteosarcoma cells when compared with normal osteoblasts. We have demonstrated for the first time that APNPs can encapsulate hydrophobic curcumin in their hydrophobic cores, and curcumin-loaded APNPs could be an innovative treatment for the selective inhibition of osteosarcoma cells.

Selective inhibition of MG-63 osteosarcoma cell proliferation induced by curcumin-loaded self-assembled arginine-rich-RGD nanospheres

PubMed Central

Chang, Run; Sun, Linlin; Webster, Thomas J

2015-01-01

Osteosarcoma is the most frequent primary malignant form of bone cancer, comprising 30% of all bone cancer cases. The objective of this in vitro study was to develop a treatment against osteosarcoma with higher selectivity toward osteosarcoma cells and lower cytotoxicity toward normal healthy osteoblast cells. Curcumin (or diferuloylmethane) has been found to have antioxidant and anticancer effects by multiple cellular pathways. However, it has lower water solubility and a higher degradation rate in alkaline conditions. In this study, the amphiphilic peptide C18GR7RGDS was used as a curcumin carrier in aqueous solution. This peptide contains a hydrophobic aliphatic tail group leading to their self-assembly by hydrophobic interactions, as well as a hydrophilic head group composed of an arginine-rich and an arginine-glycine-aspartic acid structure. Through characterization by transmission electron microscopy, self-assembled structures of spherical amphiphilic nanoparticles (APNPs) with diameters of 10–20 nm in water and phosphate-buffered saline were observed, but this structure dissociated when the pH value was reduced to 4. Using a method of codissolution with acetic acid and dialysis tubing, the solubility of curcumin was enhanced and a homogeneous solution was formed in the presence of APNPs. Successful encapsulation of curcumin in APNPs was then confirmed by Fourier transform infrared and X-ray diffraction analyses. The cytotoxicity and cellular uptake of the APNP/curcumin complexes on both osteosarcoma and normal osteoblast cell lines were also evaluated by methyl-thiazolyl-tetrazolium assays and confocal fluorescence microscopy. The results showed that the curcumin-loaded APNPs had significant selective cytotoxicity against MG-63 osteosarcoma cells when compared with normal osteoblasts. We have demonstrated for the first time that APNPs can encapsulate hydrophobic curcumin in their hydrophobic cores, and curcumin-loaded APNPs could be an innovative treatment for the selective inhibition of osteosarcoma cells. PMID:26005346

Cytoplasmic RNA Granules in Somatic Maintenance.

PubMed

Moujaber, Ossama; Stochaj, Ursula

2018-05-30

Cytoplasmic RNA granules represent subcellular compartments that are enriched in protein-bound RNA species. RNA granules are produced by evolutionary divergent eukaryotes, including yeast, mammals, and plants. The functions of cytoplasmic RNA granules differ widely. They are dictated by the cell type and physiological state, which in turn is determined by intrinsic cell properties and environmental factors. RNA granules provide diverse cellular functions. However, all of the granules contribute to aspects of RNA metabolism. This is exemplified by transcription, RNA storage, silencing, and degradation, as well as mRNP remodeling and regulated translation. Several forms of cytoplasmic mRNA granules are linked to normal physiological processes. For instance, they may coordinate protein synthesis and thereby serve as posttranscriptional "operons". RNA granules also participate in cytoplasmic mRNA trafficking, a process particularly well understood for neurons. Many forms of RNA granules support the preservation of somatic cell performance under normal and stress conditions. On the other hand, severe insults or disease can cause the formation and persistence of RNA granules that contribute to cellular dysfunction, especially in the nervous system. Neurodegeneration and many other diseases linked to RNA granules are associated with aging. Nevertheless, information related to the impact of aging on the various types of RNA granules is presently very limited. This review concentrates on cytoplasmic RNA granules and their role in somatic cell maintenance. We summarize the current knowledge on different types of RNA granules in the cytoplasm, their assembly and function under normal, stress, or disease conditions. Specifically, we discuss processing bodies, neuronal granules, stress granules, and other less characterized cytoplasmic RNA granules. Our focus is primarily on mammalian and yeast models, because they have been critical to unravel the physiological role of various RNA granules. RNA granules in plants and pathogens are briefly described. We conclude our viewpoint by summarizing the emerging concepts for RNA granule biology and the open questions that need to be addressed in future studies. © 2018 S. Karger AG, Basel.

Determination of the cytoprotective agent WR-2721 (Amifostine, Ethyol) and its metabolites in human blood using monobromobimane fluorescent labeling and high-performance liquid chromatography.

PubMed

Souid, A K; Newton, G L; Dubowy, R L; Fahey, R C; Bernstein, M L

1998-01-01

WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] is a chemoprotective agent that is currently in pediatric clinical trials. It is a prodrug that is dephosphorylated by alkaline phosphatase to the active free thiol form, WR-1065 [S-2-(3-aminopropylamino)ethanethiol]. It is likely that adequate and sustained cellular levels of the drug are necessary for optimum cytoprotection. To date, a method to measure both plasma and cellular levels of WR-2721 and its metabolites in clinical samples has not been available. In the study reported here the monobromobimane (mBBr) fluorescent labeling method was used to measure these levels when drug was added in vitro to blood samples from normal volunteers. In addition, we present pharmacokinetic data from a pediatric patient receiving WR-2721 (825 mg/m2 x 2). The results can be summarized as follows: (1) WR-2721 was detected in the patient's plasma with a half-life of about 10 min; (2) the WR-1065 concentration in the blood cellular fraction was similar to that of plasma; (3) both WR-1065 and WR-SS-low molecular weight (WR-SS-LMW) metabolites disappeared from plasma and the cellular fraction by 3.6 h after WR-2721 infusion; (4) a large proportion of WR-1065 was oxidized in plasma to WR-SS protein and WR-SS-LMW; (5) a large proportion of WR-1065 in the cellular fraction was oxidized to WR-SS-protein; (6) the WR-SS-LMW concentration in the cellular fraction was low; and (7) saturation of plasma and cellular protein binding sites was possible. The pharmacokinetic data that were generated with this technique could guide clinical trials using WR-2721.

Ultrastructural analysis of oral exfoliated epithelial cells of tobacco smokers and betel nut chewers: A scanning electron microscopy study.

PubMed

Khan, Sameera Shamim; Shreedhar, Balasundari; Kamboj, Mala

2016-01-01

The study was undertaken to correlate epithelial surface pattern changes of oral exfoliated cells of tobacco smokers and betel nut chewers and also to compare them with patients of oral squamous cell carcinoma (OSCC) and healthy individuals. In this cross-sectional study, a total of fifty persons were included in the study, out of which thirty formed the study group (15 each tobacco smokers and betel nut chewers) and twenty formed the control group (ten each of OSCC patients - positive control and ten normal buccal mucosa - negative control). Their oral exfoliated cells were scraped, fixed, and studied under scanning electron microscope (SEM). The statistical analysis was determined using ANOVA, Tukey honestly significant difference, Chi-square test, and statistical SPASS software, P < 0.05. OSCC, Individual cell modifications, intercellular relationships and surface characteristics observed by scanning electron microscopy between OSCC, tobacco smokers, betel nut chewers compared to normal oral mucosa have been tabulated. In normal oral mucosa, cell surface morphology depends on the state of keratinization of the tissue. Thus, it could prove helpful in detecting any carcinomatous change at its incipient stage and also give an insight into the ultra-structural details of cellular differentiations in epithelial tissues.

The Fate of a Normal Human Cell Traversed by a Single Charged Particle

NASA Astrophysics Data System (ADS)

Fournier, C.; Zahnreich, S.; Kraft, D.; Friedrich, T.; Voss, K.-O.; Durante, M.; Ritter, S.

2012-09-01

The long-term ``fate'' of normal human cells after single hits of charged particles is one of the oldest unsolved issues in radiation protection and cellular radiobiology. Using a high-precision heavy-ion microbeam we could target normal human fibroblasts with exactly one or five carbon ions and measured the early cytogenetic damage and the late behaviour using single-cell cloning. Around 70% of the first cycle cells presented visible aberrations in mFISH after a single ion traversal, and about 5% of the cells were still able to form colonies. In one third of selected high-proliferative colonies we observed clonal (radiation-induced) aberrations. Terminal differentiation and markers of senescence (PCNA, p16) in the descendants of cells traversed by one carbon ion occurred earlier than in controls, but no evidence of radiation-induced chromosomal instability was found. We conclude that cells surviving single-ion traversal, often carrying clonal chromosome aberrations, undergo accelerated senescence but maintain chromosomal stability.

The Fate of a Normal Human Cell Traversed by a Single Charged Particle

PubMed Central

Fournier, C.; Zahnreich, S.; Kraft, D.; Friedrich, T.; Voss, K.-O.; Durante, M.; Ritter, S.

2012-01-01

The long-term “fate” of normal human cells after single hits of charged particles is one of the oldest unsolved issues in radiation protection and cellular radiobiology. Using a high-precision heavy-ion microbeam we could target normal human fibroblasts with exactly one or five carbon ions and measured the early cytogenetic damage and the late behaviour using single-cell cloning. Around 70% of the first cycle cells presented visible aberrations in mFISH after a single ion traversal, and about 5% of the cells were still able to form colonies. In one third of selected high-proliferative colonies we observed clonal (radiation-induced) aberrations. Terminal differentiation and markers of senescence (PCNA, p16) in the descendants of cells traversed by one carbon ion occurred earlier than in controls, but no evidence of radiation-induced chromosomal instability was found. We conclude that cells surviving single-ion traversal, often carrying clonal chromosome aberrations, undergo accelerated senescence but maintain chromosomal stability. PMID:22966418

Tumor stem cells: A new approach for tumor therapy (Review)

PubMed Central

MENG, MIN; ZHAO, XIN-HAN; NING, QIAN; HOU, LEI; XIN, GUO-HONG; LIU, LI-FENG

2012-01-01

Recent studies have demonstrated the existence of a minority of tumor cells possessing the stem cell properties of self-renewal and differentiation in leukemia and several solid tumors. However, these cells do not possess the normal regulatory mechanisms of stem cells. Following transplantation, they are capable of initiating tumorigenesis and are therefore known as ‘tumor stem cells’. Cellular origin analysis of tumor stem cells has resulted in three hypotheses: Embryonal rest hypothesis, anaplasia and maturation arrest. Several signaling pathways which are involved in carcinogenesis, including Wnt/β-catenin, Notch and Oct-4 signaling pathways are crucial in normal stem cell self-renewal decisions, suggesting that breakdown in the regulation of self-renewal may be a key event in the development of tumors. Thus, tumors can be regarded as an abnormal organ in which stem cells have escaped from the normal constraints on self-renewal, thus, leading to abnormally differentiated tumor cells that lose the ability to form tumors. This new model for maligancies has significance for clinical research and treatment. PMID:22844351

[Role of placental apoptosis in fetal growth restriction].

PubMed

Liu, Yuan; Gao, Peng; Xie, Yingbo; Wang, Shuyun; Dai, Minsheng; Jiang, Sen

2002-12-01

To determine the relationship of placental cellular apoptosis and pathophysiology of fetal growth restriction (FGR). Placental samples were obtained from 18 pregnancies complicated by FGR and 14 normal pregnancies. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) and transmission electron microscopy were used to confirm the occurrence of apoptosis. In FGR group the placental apoptosis rate was (n = 18) 12.1 per thousand, the average placental weight was (236 +/- 24) g, the average birth weight was (2,071 +/- 428) g; In normal group (n = 14), the placental apoptosis rate was 7.3 per thousand, the average placental weight was (354 +/- 63) g, the average birth weight was (3,411 +/- 588) g (P < 0.05). The incidence of apoptosis was significantly higher in placental samples from pregnancies with FGR compared with normal placental samples (P < 0.05). Under transmission election microscopy, apoptosis was obviously compact and the chromatins were formed as mass. These results suggest that apoptosis may play a role in the pathophysiologic mechanisms of FGR.

Ground Testing of the EMCS Seed Cassette for Biocompatibility with the Cellular Slime Mold, Dictyostelium Discoideum

NASA Technical Reports Server (NTRS)

Hanely, Julia C.; Reinsch, Sigrid; Myers, Zachary A.; Freeman, John; Steele, Marianne K.; Sun, Gwo-Shing; Heathcote, David G.

2014-01-01

The European Modular Cultivation System, EMCS, was developed by ESA for plant experiments. To expand the use of flight verified hardware for various model organisms, we performed ground experiments to determine whether ARC EMCS Seed Cassettes could be adapted for use with cellular slime mold for future space flight experiments. Dictyostelium is a cellular slime mold that can exist both as a single-celled independent organism and as a part of a multicellular colony which functions as a unit (pseudoplasmodium). Under certain stress conditions, individual amoebae will aggregate to form multicellular structures. Developmental pathways are very similar to those found in Eukaryotic organisms, making this a uniquely interesting organism for use in genetic studies. Dictyostelium has been used as a genetic model organism for prior space flight experiments. Due to the formation of spores that are resistant to unfavorable conditions such as desiccation, Dictyostelium is also a good candidate for use in the EMCS Seed Cassettes. The growth substratum in the cassettes is a gridded polyether sulfone (PES) membrane. A blotter beneath the PES membranes contains dried growth medium. The goals of this study were to (1) verify that Dictyostelium are capable of normal growth and development on PES membranes, (2) develop a method for dehydration of Dictyostelium spores with successful recovery and development after rehydration, and (3) successful mock rehydration experiments in cassettes. Our results show normal developmental progression in two strains of Dictyostelium discoideum on PES membranes with a bacterial food source. We have successfully performed a mock rehydration of spores with developmental progression from aggregation to slug formation, and production of morphologically normal spores within 9 days of rehydration. Our results indicate that experiments on the ISS using the slime mold, Dictyostelium discoideum could potentially be performed in the flight verified hardware of the EMCS ARC Seed Cassettes.

Mapping the cellular and molecular heterogeneity of normal and malignant breast tissues and cultured cell lines

PubMed Central

2010-01-01

Introduction Normal and neoplastic breast tissues are comprised of heterogeneous populations of epithelial cells exhibiting various degrees of maturation and differentiation. While cultured cell lines have been derived from both normal and malignant tissues, it remains unclear to what extent they retain similar levels of differentiation and heterogeneity as that found within breast tissues. Methods We used 12 reduction mammoplasty tissues, 15 primary breast cancer tissues, and 20 human breast epithelial cell lines (16 cancer lines, 4 normal lines) to perform flow cytometry for CD44, CD24, epithelial cell adhesion molecule (EpCAM), and CD49f expression, as well as immunohistochemistry, and in vivo tumor xenograft formation studies to extensively analyze the molecular and cellular characteristics of breast epithelial cell lineages. Results Human breast tissues contain four distinguishable epithelial differentiation states (two luminal phenotypes and two basal phenotypes) that differ on the basis of CD24, EpCAM and CD49f expression. Primary human breast cancer tissues also contain these four cellular states, but in altered proportions compared to normal tissues. In contrast, cultured cancer cell lines are enriched for rare basal and mesenchymal epithelial phenotypes, which are normally present in small numbers within human tissues. Similarly, cultured normal human mammary epithelial cell lines are enriched for rare basal and mesenchymal phenotypes that represent a minor fraction of cells within reduction mammoplasty tissues. Furthermore, although normal human mammary epithelial cell lines exhibit features of bi-potent progenitor cells they are unable to differentiate into mature luminal breast epithelial cells under standard culture conditions. Conclusions As a group breast cancer cell lines represent the heterogeneity of human breast tumors, but individually they exhibit increased lineage-restricted profiles that fall short of truly representing the intratumoral heterogeneity of individual breast tumors. Additionally, normal human mammary epithelial cell lines fail to retain much of the cellular diversity found in human breast tissues and are enriched for differentiation states that are a minority in breast tissues, although they do exhibit features of bi-potent basal progenitor cells. These findings suggest that collections of cell lines representing multiple cell types can be used to model the cellular heterogeneity of tissues. PMID:20964822

Rewiring of cellular membrane homeostasis by picornaviruses.

PubMed

Belov, George A; Sztul, Elizabeth

2014-09-01

Viruses are obligatory intracellular parasites and utilize host elements to support key viral processes, including penetration of the plasma membrane, initiation of infection, replication, and suppression of the host's antiviral defenses. In this review, we focus on picornaviruses, a family of positive-strand RNA viruses, and discuss the mechanisms by which these viruses hijack the cellular machinery to form and operate membranous replication complexes. Studies aimed at revealing factors required for the establishment of viral replication structures identified several cellular-membrane-remodeling proteins and led to the development of models in which the virus used a preexisting cellular-membrane-shaping pathway "as is" for generating its replication organelles. However, as more data accumulate, this view is being increasingly questioned, and it is becoming clearer that viruses may utilize cellular factors in ways that are distinct from the normal functions of these proteins in uninfected cells. In addition, the proteincentric view is being supplemented by important new studies showing a previously unappreciated deep remodeling of lipid homeostasis, including extreme changes to phospholipid biosynthesis and cholesterol trafficking. The data on viral modifications of lipid biosynthetic pathways are still rudimentary, but it appears once again that the viruses may rewire existing pathways to generate novel functions. Despite remarkable progress, our understanding of how a handful of viral proteins can completely overrun the multilayered, complex mechanisms that control the membrane organization of a eukaryotic cell remains very limited. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Premature aging/senescence in cancer cells facing therapy: good or bad?

PubMed

Gonzalez, Llilians Calvo; Ghadaouia, Sabrina; Martinez, Aurélie; Rodier, Francis

2016-02-01

Normal and cancer cells facing their demise following exposure to radio-chemotherapy can actively participate in choosing their subsequent fate. These programmed cell fate decisions include true cell death (apoptosis-necroptosis) and therapy-induced cellular senescence (TIS), a permanent "proliferative arrest" commonly portrayed as premature cellular aging. Despite a permanent loss of proliferative potential, senescent cells remain viable and are highly bioactive at the microenvironment level, resulting in a prolonged impact on tissue architecture and functions. Cellular senescence is primarily documented as a tumor suppression mechanism that prevents cellular transformation. In the context of normal tissues, cellular senescence also plays important roles in tissue repair, but contributes to age-associated tissue dysfunction when senescent cells accumulate. Theoretically, in multi-step cancer progression models, cancer cells have already bypassed cellular senescence during their immortalization step (see hallmarks of cancer). It is then perhaps surprising to find that cancer cells often retain the ability to undergo TIS, or premature aging. This occurs because cellular senescence results from multiple signalling pathways, some retained in cancer cells, aiming to prevent cell cycle progression in damaged cells. Since senescent cancer cells persist after therapy and secrete an array of cytokines and growth factors that can modulate the tumor microenvironment, these cells may have beneficial and detrimental effects regarding immune modulation and survival of remaining proliferation-competent cancer cells. Similarly, while normal cells undergoing senescence are believed to remain indefinitely growth arrested, whether this is true for senescent cancer cells remains unclear, raising the possibility that these cells may represent a reservoir for cancer recurrence after treatment. This review discusses our current knowledge on cancer cell senescence and highlight questions that must be addressed to fully understand the beneficial and detrimental impacts of cellular senescence during cancer therapy.

Redox-Modulated Phenomena and Radiation Therapy: The Central Role of Superoxide Dismutases

PubMed Central

Holley, Aaron K.; Miao, Lu; St. Clair, Daret K.

2014-01-01

Abstract Significance: Ionizing radiation is a vital component in the oncologist's arsenal for the treatment of cancer. Approximately 50% of all cancer patients will receive some form of radiation therapy as part of their treatment regimen. DNA is considered the major cellular target of ionizing radiation and can be damaged directly by radiation or indirectly through reactive oxygen species (ROS) formed from the radiolysis of water, enzyme-mediated ROS production, and ROS resulting from altered aerobic metabolism. Recent Advances: ROS are produced as a byproduct of oxygen metabolism, and superoxide dismutases (SODs) are the chief scavengers. ROS contribute to the radioresponsiveness of normal and tumor tissues, and SODs modulate the radioresponsiveness of tissues, thus affecting the efficacy of radiotherapy. Critical Issues: Despite its prevalent use, radiation therapy suffers from certain limitations that diminish its effectiveness, including tumor hypoxia and normal tissue damage. Oxygen is important for the stabilization of radiation-induced DNA damage, and tumor hypoxia dramatically decreases radiation efficacy. Therefore, auxiliary therapies are needed to increase the effectiveness of radiation therapy against tumor tissues while minimizing normal tissue injury. Future Directions: Because of the importance of ROS in the response of normal and cancer tissues to ionizing radiation, methods that differentially modulate the ROS scavenging ability of cells may prove to be an important method to increase the radiation response in cancer tissues and simultaneously mitigate the damaging effects of ionizing radiation on normal tissues. Altering the expression or activity of SODs may prove valuable in maximizing the overall effectiveness of ionizing radiation. Antioxid. Redox Signal. 20, 1567–1589. PMID:24094070

Using precursor ion scan of 184 with liquid chromatography-electrospray ionization-tandem mass spectrometry for concentration normalization in cellular lipidomic studies.

PubMed

Chao, Hsi-Chun; Chen, Guan-Yuan; Hsu, Lih-Ching; Liao, Hsiao-Wei; Yang, Sin-Yu; Wang, San-Yuan; Li, Yu-Liang; Tang, Sung-Chun; Tseng, Yufeng Jane; Kuo, Ching-Hua

2017-06-08

Cellular lipidomic studies have been favored approaches in many biomedical research areas. To provide fair comparisons of the studied cells, it is essential to perform normalization of the determined concentration before lipidomic analysis. This study proposed a cellular lipidomic normalization method by measuring the phosphatidylcholine (PC) and sphingomyelin (SM) contents in cell extracts. To provide efficient analysis of PC and SM in cell extracts, flow injection analysis-electrospray ionization-tandem mass spectrometry (FIA-ESI-MS/MS) with a precursor ion scan (PIS) of m/z 184 was used, and the parameters affecting the performance of the method were optimized. Good linearity could be observed between the cell extract dilution factor and the reciprocal of the total ion chromatogram (TIC) area in the PIS of m/z 184 within the dilution range of 1- to 16-fold (R 2  = 0.998). The calibration curve could be used for concentration adjustment of the unknown concentration of a cell extract. The intraday and intermediate precisions were below 10%. The accuracy ranged from 93.0% to 105.6%. The performance of the new normalization method was evaluated using different numbers of HCT-116 cells. Sphingosine, ceramide (d18:1/18:0), SM (d18:1/18:0) and PC (16:1/18:0) were selected as the representative test lipid species, and the results showed that the peak areas of each lipid species obtained from different cell numbers were within a 20% variation after normalization. Finally, the PIS of 184 normalization method was applied to study ischemia-induced neuron injury using oxygen and glucose deprivation (OGD) on primary neuronal cultured cells. Our results showed that the PIS of 184 normalization method is an efficient and effective approach for concentration normalization in cellular lipidomic studies. Copyright © 2017 Elsevier B.V. All rights reserved.

qpure: A Tool to Estimate Tumor Cellularity from Genome-Wide Single-Nucleotide Polymorphism Profiles

PubMed Central

Song, Sarah; Nones, Katia; Miller, David; Harliwong, Ivon; Kassahn, Karin S.; Pinese, Mark; Pajic, Marina; Gill, Anthony J.; Johns, Amber L.; Anderson, Matthew; Holmes, Oliver; Leonard, Conrad; Taylor, Darrin; Wood, Scott; Xu, Qinying; Newell, Felicity; Cowley, Mark J.; Wu, Jianmin; Wilson, Peter; Fink, Lynn; Biankin, Andrew V.; Waddell, Nic; Grimmond, Sean M.; Pearson, John V.

2012-01-01

Tumour cellularity, the relative proportion of tumour and normal cells in a sample, affects the sensitivity of mutation detection, copy number analysis, cancer gene expression and methylation profiling. Tumour cellularity is traditionally estimated by pathological review of sectioned specimens; however this method is both subjective and prone to error due to heterogeneity within lesions and cellularity differences between the sample viewed during pathological review and tissue used for research purposes. In this paper we describe a statistical model to estimate tumour cellularity from SNP array profiles of paired tumour and normal samples using shifts in SNP allele frequency at regions of loss of heterozygosity (LOH) in the tumour. We also provide qpure, a software implementation of the method. Our experiments showed that there is a medium correlation 0.42 (-value = 0.0001) between tumor cellularity estimated by qpure and pathology review. Interestingly there is a high correlation 0.87 (-value 2.2e-16) between cellularity estimates by qpure and deep Ion Torrent sequencing of known somatic KRAS mutations; and a weaker correlation 0.32 (-value = 0.004) between IonTorrent sequencing and pathology review. This suggests that qpure may be a more accurate predictor of tumour cellularity than pathology review. qpure can be downloaded from https://sourceforge.net/projects/qpure/. PMID:23049875

Transient expression of protein tyrosine phosphatases encoded in Cotesia plutellae bracovirus inhibits insect cellular immune responses

NASA Astrophysics Data System (ADS)

Ibrahim, Ahmed M. A.; Kim, Yonggyun

2008-01-01

Several immunosuppressive factors are associated with parasitism of an endoparasitoid wasp, Cotesia plutellae, on the diamondback moth, Plutella xylostella. C. plutellae bracovirus (CpBV) encodes a large number of putative protein tyrosine phosphatases (PTPs), which may play a role in inhibiting host cellular immunity. To address this inhibitory hypothesis of CpBV-PTPs, we performed transient expression of individual CpBV-PTPs in hemocytes of the beet armyworm, Spodoptera exigua, and analyzed their cellular immune responses. Two different forms of CpBV-PTPs were chosen and cloned into a eukaryotic expression vector under the control of the p10 promoter of baculovirus: one with the normal cysteine active site (CpBV-PTP1) and the other with a mutated active site (CpBV-PTP5). The hemocytes transfected with CpBV-PTP1 significantly increased in PTP activity compared to control hemocytes, but those with CpBV-PTP5 exhibited a significant decrease in the PTP activity. All transfected hemocytes exhibited a significant reduction in both cell spreading and encapsulation activities compared to control hemocytes. Co-transfection of CpBV-PTP1 together with its double-stranded RNA reduced the messenger RNA (mRNA) level of CpBV-PTP1 and resulted in recovery of both hemocyte behaviors. This is the first report demonstrating that the polydnaviral PTPs can manipulate PTP activity of the hemocytes to interrupt cellular immune responses.

Melt-processed polymeric cellular dosage forms for immediate drug release.

PubMed

Blaesi, Aron H; Saka, Nannaji

2015-12-28

The present immediate-release solid dosage forms, such as the oral tablets and capsules, comprise granular matrices. While effective in releasing the drug rapidly, they are fraught with difficulties inherent in processing particulate matter. By contrast, liquid-based processes would be far more predictable; but the standard cast microstructures are unsuited for immediate-release because they resist fluid percolation and penetration. In this article, we introduce cellular dosage forms that can be readily prepared from polymeric melts by incorporating the nucleation, growth, and coalescence of microscopic gas bubbles in a molding process. We show that the cell topology and formulation of such cellular structures can be engineered to reduce the length-scale of the mass-transfer step, which determines the time of drug release, from as large as the dosage form itself to as small as the thickness of the cell wall. This allows the cellular dosage forms to achieve drug release rates over an order of magnitude faster compared with those of cast matrices, spanning the entire spectrum of immediate-release and beyond. The melt-processed polymeric cellular dosage forms enable predictive design of immediate-release solid dosage forms by tailoring microstructures, and could be manufactured efficiently in a single step.

A branching process model for the analysis of abortive colony size distributions in carbon ion-irradiated normal human fibroblasts.

PubMed

Sakashita, Tetsuya; Hamada, Nobuyuki; Kawaguchi, Isao; Hara, Takamitsu; Kobayashi, Yasuhiko; Saito, Kimiaki

2014-05-01

A single cell can form a colony, and ionizing irradiation has long been known to reduce such a cellular clonogenic potential. Analysis of abortive colonies unable to continue to grow should provide important information on the reproductive cell death (RCD) following irradiation. Our previous analysis with a branching process model showed that the RCD in normal human fibroblasts can persist over 16 generations following irradiation with low linear energy transfer (LET) γ-rays. Here we further set out to evaluate the RCD persistency in abortive colonies arising from normal human fibroblasts exposed to high-LET carbon ions (18.3 MeV/u, 108 keV/µm). We found that the abortive colony size distribution determined by biological experiments follows a linear relationship on the log-log plot, and that the Monte Carlo simulation using the RCD probability estimated from such a linear relationship well simulates the experimentally determined surviving fraction and the relative biological effectiveness (RBE). We identified the short-term phase and long-term phase for the persistent RCD following carbon-ion irradiation, which were similar to those previously identified following γ-irradiation. Taken together, our results suggest that subsequent secondary or tertiary colony formation would be invaluable for understanding the long-lasting RCD. All together, our framework for analysis with a branching process model and a colony formation assay is applicable to determination of cellular responses to low- and high-LET radiation, and suggests that the long-lasting RCD is a pivotal determinant of the surviving fraction and the RBE.

GCK-MODY diabetes associated with protein misfolding, cellular self-association and degradation.

PubMed

Negahdar, Maria; Aukrust, Ingvild; Johansson, Bente B; Molnes, Janne; Molven, Anders; Matschinsky, Franz M; Søvik, Oddmund; Kulkarni, Rohit N; Flatmark, Torgeir; Njølstad, Pål Rasmus; Bjørkhaug, Lise

2012-11-01

GCK-MODY, dominantly inherited mild fasting hyperglycemia, has been associated with >600 different mutations in the glucokinase (GK)-encoding gene (GCK). When expressed as recombinant pancreatic proteins, some mutations result in enzymes with normal/near-normal catalytic properties. The molecular mechanism(s) of GCK-MODY due to these mutations has remained elusive. Here, we aimed to explore the molecular mechanisms for two such catalytically 'normal' GCK mutations (S263P and G264S) in the F260-L270 loop of GK. When stably overexpressed in HEK293 cells and MIN6 β-cells, the S263P- and G264S-encoded mutations generated misfolded proteins with an increased rate of degradation (S263P>G264S) by the protein quality control machinery, and a propensity to self-associate (G264S>S263P) and form dimers (SDS resistant) and aggregates (partly Triton X-100 insoluble), as determined by pulse-chase experiments and subcellular fractionation. Thus, the GCK-MODY mutations S263P and G264S lead to protein misfolding causing destabilization, cellular dimerization/aggregation and enhanced rate of degradation. In silico predicted conformational changes of the F260-L270 loop structure are considered to mediate the dimerization of both mutant proteins by a domain swapping mechanism. Thus, similar properties may represent the molecular mechanisms for additional unexplained GCK-MODY mutations, and may also contribute to the disease mechanism in other previously characterized GCK-MODY inactivating mutations. Copyright © 2012 Elsevier B.V. All rights reserved.

Production of cattle lacking prion protein

PubMed Central

Richt, Jürgen A; Kasinathan, Poothappillai; Hamir, Amir N; Castilla, Joaquin; Sathiyaseelan, Thillai; Vargas, Francisco; Sathiyaseelan, Janaki; Wu, Hua; Matsushita, Hiroaki; Koster, Julie; Kato, Shinichiro; Ishida, Isao; Soto, Claudio; Robl, James M; Kuroiwa, Yoshimi

2010-01-01

Prion diseases are caused by propagation of misfolded forms of the normal cellular prion protein PrPC, such as PrPBSE in bovine spongiform encephalopathy (BSE) in cattle and PrPCJD in Creutzfeldt-Jakob disease (CJD) in humans1. Disruption of PrPC expression in mice, a species that does not naturally contract prion diseases, results in no apparent developmental abnormalities2–5. However, the impact of ablating PrPC function in natural host species of prion diseases is unknown. Here we report the generation and characterization of PrPC-deficient cattle produced by a sequential gene-targeting system6. At over 20 months of age, the cattle are clinically, physiologically, histopathologically, immunologically and reproductively normal. Brain tissue homogenates are resistant to prion propagation in vitro as assessed by protein misfolding cyclic amplification7. PrPC-deficient cattle may be a useful model for prion research and could provide industrial bovine products free of prion proteins. PMID:17195841

Influence of antigenic competition on the development of antibody-forming cell clones.

PubMed Central

Pritchard-Briscoe, H; McDougall, C; Inchley, C J

1977-01-01

Isoelectric focusing in polyacrylamide gels was used to investigate the anti-sheep red blood cell antibody responses of mice subjected to antigenic competition. A reduction in the number and intensity of antibody bands was found, even in situations where the suppression of IgG antibody titres was minimal, while with large reductions in titre, antibody bands were rarely seen. It thus appeared that the output of individual B-cell clones was severely depressed during competition. It was concluded that inhibition of clonal expansion is an important feature of competition, and that this may reflect a normal regulatory activity which acts to limit cellular proliferation during immune responses. This conclusion was supported by observations on the level of DNA synthesis, following immunization with sheep red cells, in the spleens of normal and suppressed mice. Images Fig. 2 Fig. 3 Fig. 4 PMID:300313

Metabolic activation and nucleic acid binding of acetaminophen and related arylamine substrates by the respiratory burst of human granulocytes.

PubMed

Corbett, M D; Corbett, B R; Hannothiaux, M H; Quintana, S J

1989-01-01

Following stimulation with phorbol myristate acetate, human granulocytes were found to incorporate acetaminophen, p-phenetidine, p-aminophenol, and p-chloroaniline into cellular DNA and RNA. Phenacetin was not incorporated into nucleic acid or metabolized by such activated granulocytes. None of the substrates gave nucleic acid binding if the granulocyte cultures were not induced to undergo the respiratory burst. Additional studies on the binding of acetaminophen to DNA and RNA were made by use of both ring-14C-labeled and carbonyl-14C-labeled forms of this substrate. The finding that equivalent amounts of these two labeled acetaminophen substrates were bound to cellular DNA demonstrated that the intact acetaminophen molecule was incorporated into DNA. On the other hand, the finding that excess ring-14C-labeled acetaminophen was incorporated into cellular RNA implies partial hydrolysis of the acetaminophen substrate prior to RNA binding. Evidence was presented which strongly indicates that the nucleic acid binding of the substrates was covalent in nature. The inability of the respiratory burst to result in the binding of phenacetin to nucleic acid suggests that arylamides are not normally activated or metabolized by activated granulocytes. Acetaminophen is an exception to the recalcitrance of arylamides to such bioactivation processes because it also possesses the phenolic functional group, which, like the arylamine group, is oxidized by certain reactive oxygen species. Myeloperoxidase appears to be much more important in the binding of acetaminophen to DNA than it is in the DNA binding of arylamines in general. The role of the respiratory burst in causing the bioactivation of certain arylamines, which are not normally genotoxic via the more usual microsomal activation pathways, was extended to include certain amide substrates such as acetaminophen.

Radiation-quality dependent cellular response in mutation induction in normal human cells.

PubMed

Suzuki, Masao; Tsuruoka, Chizuru; Uchihori, Yukio; Kitamura, Hisashi; Liu, Cui Hua

2009-09-01

We studied cellular responses in normal human fibroblasts induced with low-dose (rate) or low-fluence irradiations of different radiation types, such as gamma rays, neutrons and high linear energy transfer (LET) heavy ions. The cells were pretreated with low-dose (rate) or low-fluence irradiations (approximately 1 mGy/7-8 h) of 137Cs gamma rays, 241Am-Be neutrons, helium, carbon and iron ions before irradiations with an X-ray challenging dose (1.5 Gy). Helium (LET = 2.3 keV/microm), carbon (LET = 13.3 keV/microm) and iron (LET = 200 keV/microm) ions were produced by the Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan. No difference in cell-killing effect, measured by a colony forming assay, was observed among the pretreatment with different radiation types. In mutation induction, which was detected in the hypoxanthine-guanine phosphoribosyltransferase (hprt) locus to measure 6-thioguanine resistant clones, there was no difference in mutation frequency induced by the X-ray challenging dose between unpretreated and gamma-ray pretreated cells. In the case of the pretreatment of heavy ions, X-ray-induced mutation was around 1.8 times higher in helium-ion pretreated and 4.0 times higher in carbon-ion pretreated cells than in unpretreated cells (X-ray challenging dose alone). However, the mutation frequency in cells pretreated with iron ions was the same level as either unpretreated or gamma-ray pretreated cells. In contrast, it was reduced at 0.15 times in cells pretreated with neutrons when compared to unpretreated cells. The results show that cellular responses caused by the influence of hprt mutation induced in cells pretreated with low-dose-rate or low-fluence irradiations of different radiation types were radiation-quality dependent manner.

Investigation of phosphoserine and cytidine 5'-phosphate by heteronuclear two-dimensional spectroscopy: samples with strong proton coupling

NASA Astrophysics Data System (ADS)

Bolton, Philip H.

Heteronuclear two-dimensional magnetic resonance is a novel method for investigating the conformations of cellular phosphates. The two-dimensional proton spectra are detected indirectly via the phosphorus-31 nucleus and thus allow determination of proton chemical shifts and coupling constants in situations in which the normal proton spectrum is obscured. Previous investigations of cellular phosphates with relatively simple spin systems have shown that the two-dimensional proton spectrum can be readily related to the normal proton spectrum by subspectral analysis. The normal proton spectrum can be decomposed into two subspectra, one for each polarization of the phosphorus-31 nucleus. The two-dimensional spectrum arises from the difference between the subspectra, and the normal proton spectrum is the sum. This allows simulation of the two-dimensional spectra and hence determination of the proton chemical shifts and coupling constants. Many cellular phosphates of interest, such as 5'-nucleotides and phosphoserine, contain three protons coupled to the phosphorus which are strongly coupled to one another. These samples are amenable to the two-dimensional method and the straightforward subspectral analysis is preserved when a 90° pulse is applied to the protons in the magnetization transfer step. The two-dimensional proton spectra of the samples investigated here have higher resolution than the normal proton spectra, revealing spectral features not readily apparent in the normal proton spectra.

Free radicals and related reactive species as mediators of tissue injury and disease: implications for Health.

PubMed

Kehrer, James P; Klotz, Lars-Oliver

2015-01-01

A radical is any molecule that contains one or more unpaired electrons. Radicals are normal products of many metabolic pathways. Some exist in a controlled (caged) form as they perform essential functions. Others exist in a free form and interact with various tissue components. Such interactions can cause both acute and chronic dysfunction, but can also provide essential control of redox regulated signaling pathways. The potential roles of endogenous or xenobiotic-derived free radicals in several human pathologies have stimulated extensive research linking the toxicity of numerous xenobiotics and disease processes to a free radical mechanism. In recent years, improvements in analytical methodologies, as well as the realization that subtle effects induced by free radicals and oxidants are important in modulating cellular signaling, have greatly improved our understanding of the roles of these reactive species in toxic mechanisms and disease processes. However, because free radical-mediated changes are pervasive, and a consequence as well as a cause of injury, whether such species are a major cause of tissue injury and human disease remains unclear. This concern is supported by the fact that the bulk of antioxidant defenses are enzymatic and the findings of numerous studies showing that exogenously administered small molecule antioxidants are unable to affect the course of most toxicities and diseases purported to have a free radical mechanism. This review discusses cellular sources of various radical species and their reactions with vital cellular constituents, and provides examples of selected disease processes that may have a free radical component.

Semi-quantitative estimation of cellular SiO2 nanoparticles using flow cytometry combined with X-ray fluorescence measurements.

PubMed

Choi, Seo Yeon; Yang, Nuri; Jeon, Soo Kyung; Yoon, Tae Hyun

2014-09-01

In this study, we have demonstrated feasibility of a semi-quantitative approach for the estimation of cellular SiO2 nanoparticles (NPs), which is based on the flow cytometry measurements of their normalized side scattering intensity. In order to improve our understanding on the quantitative aspects of cell-nanoparticle interactions, flow cytometry, transmission electron microscopy, and X-ray fluorescence experiments were carefully performed for the HeLa cells exposed to SiO2 NPs with different core diameters, hydrodynamic sizes, and surface charges. Based on the observed relationships among the experimental data, a semi-quantitative cellular SiO2 NPs estimation method from their normalized side scattering and core diameters was proposed, which can be applied for the determination of cellular SiO2 NPs within their size-dependent linear ranges. © 2014 International Society for Advancement of Cytometry.

Activation of cellular death programs associated with immunosenescence-like phenotype in TPPII knockout mice

PubMed Central

Huai, Jisen; Firat, Elke; Nil, Ahmed; Million, Daniele; Gaedicke, Simone; Kanzler, Benoit; Freudenberg, Marina; van Endert, Peter; Kohler, Gabriele; Pahl, Heike L.; Aichele, Peter; Eichmann, Klaus; Niedermann, Gabriele

2008-01-01

The giant cytosolic protease tripeptidyl peptidase II (TPPII) has been implicated in the regulation of proliferation and survival of malignant cells, particularly lymphoma cells. To address its functions in normal cellular and systemic physiology we have generated TPPII-deficient mice. TPPII deficiency activates cell type-specific death programs, including proliferative apoptosis in several T lineage subsets and premature cellular senescence in fibroblasts and CD8+ T cells. This coincides with up-regulation of p53 and dysregulation of NF-κB. Prominent degenerative alterations at the organismic level were a decreased lifespan and symptoms characteristic of immunohematopoietic senescence. These symptoms include accelerated thymic involution, lymphopenia, impaired proliferative T cell responses, extramedullary hematopoiesis, and inflammation. Thus, TPPII is important for maintaining normal cellular and systemic physiology, which may be relevant for potential therapeutic applications of TPPII inhibitors. PMID:18362329

High vascular delivery of EGF, but low receptor binding rate is observed in AsPC-1 tumors as compared to normal pancreas.

PubMed

Samkoe, Kimberley S; Sexton, Kristian; Tichauer, Kenneth M; Hextrum, Shannon K; Pardesi, Omar; Davis, Scott C; O'Hara, Julia A; Hoopes, P Jack; Hasan, Tayyaba; Pogue, Brian W

2012-08-01

Cellular receptor targeted imaging agents present the potential to target extracellular molecular expression in cancerous lesions; however, the image contrast in vivo does not reflect the magnitude of overexpression expected from in vitro data. Here, the in vivo delivery and binding kinetics of epidermal growth factor receptor (EGFR) was determined for normal pancreas and AsPC-1 orthotopic pancreatic tumors known to overexpress EGFR. EGFR in orthotopic xenograft AsPC-1 tumors was targeted with epidermal growth factor (EGF) conjugated with IRDye800CW. The transfer rate constants (k(e), K₁₂, k₂₁, k₂₃, and k₃₂) associated with a three-compartment model describing the vascular delivery, leakage rate and binding of targeted agents were determined experimentally. The plasma excretion rate, k (e), was determined from extracted blood plasma samples. K₁₂, k₂₁, and k₃₂ were determined from ex vivo tissue washing studies at time points ≥ 24 h. The measured in vivo uptake of IRDye800CW-EGF and a non-targeted tracer dye, IRDye700DX-carboxylate, injected simultaneously was used to determined k₂₃. The vascular exchange of IRDye800CW-EGF in the orthotopic tumor (K₁₂ and k₂₁) was higher than in the AsPC-1 tumor as compared to normal pancreas, suggesting that more targeted agent can be taken up in tumor tissue. However, the cellular associated (binding) rate constant (k₂₃) was slightly lower for AsPC-1 pancreatic tumor (4.1 × 10(-4) s(-1)) than the normal pancreas (5.5 × 10(-4) s(-1)), implying that less binding is occurring. Higher vascular delivery but low cellular association in the AsPC-1 tumor compared to the normal pancreas may be indicative of low receptor density due to low cellular content. This attribute of the AsPC-1 tumor may indicate one contributing cause of the difficulty in treating pancreatic tumors with cellular targeted agents.

Luminal mitosis drives epithelial cell dispersal within the branching ureteric bud

PubMed Central

Packard, Adam; Georgas, Kylie; Michos, Odyssé; Riccio, Paul; Cebrian, Cristina; Combes, Alexander N.; Ju, Adler; Ferrer-Vaquer, Anna; Hadjantonakis, Anna-Katerina; Zong, Hui; Little, Melissa H.; Costantini, Frank

2013-01-01

Summary The ureteric bud is an epithelial tube that undergoes branching morphogenesis to form the renal collecting system. Though development of a normal kidney depends on proper ureteric bud morphogenesis, the cellular events underlying this process remain obscure. Here, we used time-lapse microscopy together with several genetic labeling methods to observe ureteric bud cell behaviors in developing mouse kidneys. We observed an unexpected cell behavior in the branching tips of the ureteric bud, which we term “mitosis-associated cell dispersal”. Pre-mitotic ureteric tip cells delaminate from the epithelium and divide within the lumen; while one daughter cell retains a basal process, allowing it to reinsert into the epithelium at the site of origin, the other daughter cell reinserts at a position one to three cell diameters away. Given the high rate of cell division in ureteric tips, this cellular behavior causes extensive epithelial cell rearrangements that may contribute to renal branching morphogenesis. PMID:24183650

Improved intra-array and interarray normalization of peptide microarray phosphorylation for phosphorylome and kinome profiling by rational selection of relevant spots

PubMed Central

Scholma, Jetse; Fuhler, Gwenny M.; Joore, Jos; Hulsman, Marc; Schivo, Stefano; List, Alan F.; Reinders, Marcel J. T.; Peppelenbosch, Maikel P.; Post, Janine N.

2016-01-01

Massive parallel analysis using array technology has become the mainstay for analysis of genomes and transcriptomes. Analogously, the predominance of phosphorylation as a regulator of cellular metabolism has fostered the development of peptide arrays of kinase consensus substrates that allow the charting of cellular phosphorylation events (often called kinome profiling). However, whereas the bioinformatical framework for expression array analysis is well-developed, no advanced analysis tools are yet available for kinome profiling. Especially intra-array and interarray normalization of peptide array phosphorylation remain problematic, due to the absence of “housekeeping” kinases and the obvious fallacy of the assumption that different experimental conditions should exhibit equal amounts of kinase activity. Here we describe the development of analysis tools that reliably quantify phosphorylation of peptide arrays and that allow normalization of the signals obtained. We provide a method for intraslide gradient correction and spot quality control. We describe a novel interarray normalization procedure, named repetitive signal enhancement, RSE, which provides a mathematical approach to limit the false negative results occuring with the use of other normalization procedures. Using in silico and biological experiments we show that employing such protocols yields superior insight into cellular physiology as compared to classical analysis tools for kinome profiling. PMID:27225531

Determination of the mechanical properties of solid and cellular polymeric dosage forms by diametral compression.

PubMed

Blaesi, Aron H; Saka, Nannaji

2016-07-25

At present, the immediate-release solid dosage forms, such as the oral tablets and capsules, are granular solids. They release drug rapidly and have adequate mechanical properties, but their manufacture is fraught with difficulties inherent in processing particulate matter. Such difficulties, however, could be overcome by liquid-based processing. Therefore, we have recently introduced polymeric cellular (i.e., highly porous) dosage forms prepared from a melt process. Experiments have shown that upon immersion in a dissolution medium, the cellular dosage forms with polyethylene glycol (PEG) as excipient and with predominantly open-cell topology disintegrate by exfoliation, thus enabling rapid drug release. If the volume fraction of voids of the open-cell structures is too large, however, their mechanical strength is adversely affected. At present, the common method for determining the tensile strength of brittle, solid dosage forms (such as select granular forms) is the diametral compression test. In this study, the theory of diametral compression is first refined to demonstrate that the relevant mechanical properties of ductile and cellular solids (i.e., the elastic modulus and the yield strength) can also be extracted from this test. Diametral compression experiments are then conducted on PEG-based solid and cellular dosage forms. It is found that the elastic modulus and yield strength of the open-cell structures are about an order of magnitude smaller than those of the non-porous solids, but still are substantially greater than the stiffness and strength requirements for handling the dosage forms manually. This work thus demonstrates that melt-processed polymeric cellular dosage forms that release drug rapidly can be designed and manufactured to have adequate mechanical properties. Copyright © 2016. Published by Elsevier B.V.

Structural Plasticity and Conformational Transitions of HIV Envelope Glycoprotein gp120

PubMed Central

Korkut, Anil; Hendrickson, Wayne A.

2012-01-01

HIV envelope glycoproteins undergo large-scale conformational changes as they interact with cellular receptors to cause the fusion of viral and cellular membranes that permits viral entry to infect targeted cells. Conformational dynamics in HIV gp120 are also important in masking conserved receptor epitopes from being detected for effective neutralization by the human immune system. Crystal structures of HIV gp120 and its complexes with receptors and antibody fragments provide high-resolution pictures of selected conformational states accessible to gp120. Here we describe systematic computational analyses of HIV gp120 plasticity in such complexes with CD4 binding fragments, CD4 mimetic proteins, and various antibody fragments. We used three computational approaches: an isotropic elastic network analysis of conformational plasticity, a full atomic normal mode analysis, and simulation of conformational transitions with our coarse-grained virtual atom molecular mechanics (VAMM) potential function. We observe collective sub-domain motions about hinge points that coordinate those motions, correlated local fluctuations at the interfacial cavity formed when gp120 binds to CD4, and concerted changes in structural elements that form at the CD4 interface during large-scale conformational transitions to the CD4-bound state from the deformed states of gp120 in certain antibody complexes. PMID:23300605

The biomolecular corona is retained during nanoparticle uptake and protects the cells from the damage induced by cationic nanoparticles until degraded in the lysosomes.

PubMed

Wang, Fengjuan; Yu, Lu; Monopoli, Marco P; Sandin, Peter; Mahon, Eugene; Salvati, Anna; Dawson, Kenneth A

2013-11-01

Nanoparticles have unique capacities of interacting with the cellular machinery and entering cells. To be able to exploit this potential, it is essential to understand what controls the interactions at the interface between nanoparticles and cells: it is now established that nanoparticles in biological media are covered by proteins and other biomolecules forming a "corona" on the nanoparticle surface, which confers a new identity to the nanoparticles. By labelling the proteins of the serum, using positively-charged polystyrene, we now show that this adsorbed layer is strong enough to be retained on the nanoparticles as they enter cells and is trafficked to the lysosomes on the nanoparticles. There, the corona is degraded and this is followed by lysosomal damage, leading to cytosolic release of lysosomal content, and ultimately apoptosis. Thus the corona protects the cells from the damage induced by the bare nanoparticle surface until enzymatically cleared in the lysosomes. This study investigates the effects of protein corona that normally forms on the surface of nanoparticles during in vivo use, describing the steps of intracellular processing of such particles, to enhance our understanding of how these particles interact with the cellular machinery. Copyright © 2013 Elsevier Inc. All rights reserved.

Advax™, a novel microcrystalline polysaccharide particle engineered from delta inulin, provides robust adjuvant potency together with tolerability and safety

PubMed Central

Petrovsky, Nikolai; Cooper, Peter D.

2015-01-01

There is an ongoing need for new adjuvants to facilitate development of vaccines against HIV, tuberculosis, malaria and cancer, amongst many others. Unfortunately, the most potent adjuvants are often associated with toxicity and safety issues. Inulin, a plant-derived polysaccharide, has no immunological activity in its native soluble form but when crystallised into stable microparticles (delta inulin) acquires potent adjuvant activity. Delta inulin has been shown to enhance humoral and cellular immune responses against a broad range of co-administered viral, bacterial, parasitic and toxin antigens. Inulin normally crystallises as large heterogeneous particles with a broad size distribution and variable solubility temperatures. To ensure reproducible delta inulin particles with a consistent size distribution and temperature of solubility, a current Good Manufacturing Practice (cGMP) process was designed to produce Advax™ adjuvant. In its cGMP form, Advax™ adjuvant has proved successful in human trials of vaccines against seasonal and pandemic influenza, hepatitis B and insect sting anaphylaxis, enhancing antibody and T-cell responses while at the same time being safe and well tolerated. Advax™ adjuvant thereby represents a novel human adjuvant with positive effects on both humoral and cellular immunity. This review describes the discovery and development of Advax™ adjuvant and research into its unique mechanism of action. PMID:26407920

Ex vivo 2D and 3D HSV-2 infection model using human normal vaginal epithelial cells.

PubMed

Zhu, Yaqi; Yang, Yan; Guo, Juanjuan; Dai, Ying; Ye, Lina; Qiu, Jianbin; Zeng, Zhihong; Wu, Xiaoting; Xing, Yanmei; Long, Xiang; Wu, Xufeng; Ye, Lin; Wang, Shubin; Li, Hui

2017-02-28

Herpes simplex virus type 2 (HSV-2) infects human genital mucosa and establishes life-long latent infection. It is unmet need to establish a human cell-based microphysiological system for virus biology and anti-viral drug discovery. One of barriers is lacking of culture system of normal epithelial cells in vitro over decades. In this study, we established human normal vaginal epithelial cell (HNVEC) culture using co-culture system. HNVEC cells were then propagated rapidly and stably in a defined culture condition. HNVEC cells exhibited a normal diploid karyotype and formed the well-defined and polarized spheres in matrigel three-dimension (3D) culture, while malignant cells (HeLa) formed disorganized and nonpolar solid spheres. HNVEC cells had a normal cellular response to DNA damage and had no transforming property using soft agar assays. HNVEC expressed epithelial marker cytokeratin 14 (CK14) and p63, but not cytokeratin 18 (CK18). Next, we reconstructed HNVEC-derived 3D vaginal epithelium using air-liquid interface (ALI) culture. This 3D vaginal epithelium has the basal and apical layers with expression of epithelial markers as its originated human vaginal tissue. Finally, we established an HSV-2 infection model based on the reconstructed 3D vaginal epithelium. After inoculation of HSV-2 (G strain) at apical layer of the reconstructed 3D vaginal epithelium, we observed obvious pathological effects gradually spreading from the apical layer to basal layer with expression of a viral protein. Thus, we established an ex vivo 2D and 3D HSV-2 infection model that can be used for HSV-2 virology and anti-viral drug discovery.

Drosophila Uri, a PP1α binding protein, is essential for viability, maintenance of DNA integrity and normal transcriptional activity

PubMed Central

Kirchner, Jasmin; Vissi, Emese; Gross, Sascha; Szoor, Balazs; Rudenko, Andrey; Alphey, Luke; White-Cooper, Helen

2008-01-01

Background Protein phosphatase 1 (PP1) is involved in diverse cellular processes, and is targeted to substrates via interaction with many different protein binding partners. PP1 catalytic subunits (PP1c) fall into PP1α and PP1β subfamilies based on sequence analysis, however very few PP1c binding proteins have been demonstrated to discriminate between PP1α and PP1β. Results URI (unconventional prefoldin RPB5 interactor) is a conserved molecular chaperone implicated in a variety of cellular processes, including the transcriptional response to nutrient signalling and maintenance of DNA integrity. We show that Drosophila Uri binds PP1α with much higher affinity than PP1β, and that this ability to discriminate between PP1c forms is conserved to humans. Most Uri is cytoplasmic, however we found some protein associated with active RNAPII on chromatin. We generated a uri loss of function allele, and show that uri is essential for viability in Drosophila. uri mutants have transcriptional defects, reduced cell viability and differentiation in the germline, and accumulate DNA damage in their nuclei. Conclusion Uri is the first PP1α specific binding protein to be described in Drosophila. Uri protein plays a role in transcriptional regulation. Activity of uri is required to maintain DNA integrity and cell survival in normal development. PMID:18412953

Oncogenes in retroviruses and cells

NASA Astrophysics Data System (ADS)

Kurth, Reinhard

1983-09-01

Oncogenes are genes that cause cancer. Retroviruses contain oncogenes and cause cancer in animals and, perhaps, in man. The viruses have appropriated their oncogenes from normal cellular DNA by genetic recombination. Correspondingly, uninfected vertebrate cells contain a family of evolutionary conserved cellular oncogenes. Retrovirus infection, introducing additional viral oncogenes into the cells, as well as carcinogen-mediated activation of cellular oncogenes may both lead to increased synthesis of oncogene encoded transforming proteins which convert normal cells to tumor cells. Unique retroviruses of human origin have recently been identified. They may, on occasion, directly cause tumors in man. However, the general significance of retroviruses may better be illustrated by their remarkable genetic composition which allows them to promote tumor growth by a variety of genetic mechanisms.

A self-organized criticality model for ion temperature gradient mode driven turbulence in confined plasma

NASA Astrophysics Data System (ADS)

Isliker, H.; Pisokas, Th.; Strintzi, D.; Vlahos, L.

2010-08-01

A new self-organized criticality (SOC) model is introduced in the form of a cellular automaton (CA) for ion temperature gradient (ITG) mode driven turbulence in fusion plasmas. Main characteristics of the model are that it is constructed in terms of the actual physical variable, the ion temperature, and that the temporal evolution of the CA, which necessarily is in the form of rules, mimics actual physical processes as they are considered to be active in the system, i.e., a heating process and a local diffusive process that sets on if a threshold in the normalized ITG R /LT is exceeded. The model reaches the SOC state and yields ion temperature profiles of exponential shape, which exhibit very high stiffness, in that they basically are independent of the loading pattern applied. This implies that there is anomalous heat transport present in the system, despite the fact that diffusion at the local level is imposed to be of a normal kind. The distributions of the heat fluxes in the system and of the heat out-fluxes are of power-law shape. The basic properties of the model are in good qualitative agreement with experimental results.

Gravitational Effects on Cellular Flame Structure

NASA Technical Reports Server (NTRS)

Dunsky, C. M.; Fernandez-Pello, A. C.

1991-01-01

An experimental investigation has been conducted of the effect of gravity on the structure of downwardly propagating, cellular premixed propane-oxygen-nitrogen flames anchored on a water-cooled porous-plug burner. The flame is subjected to microgravity conditions in the NASA Lewis 2.2-second drop tower, and flame characteristics are recorded on high-speed film. These are compared to flames at normal gravity conditions with the same equivalence ratio, dilution index, mixture flow rate, and ambient pressure. The results show that the cellular instability band, which is located in the rich mixture region, changes little under the absence of gravity. Lifted normal-gravity flames near the cellular/lifted limits, however, are observed to become cellular when gravity is reduced. Observations of a transient cell growth period following ignition point to heat loss as being an important mechanism in the overall flame stability, dominating the stabilizing effect of buoyancy for these downwardly-propagating burner-anchored flames. The pulsations that are observed in the plume and diffusion flame generated downstream of the premixed flame in the fuel rich cases disappear in microgravity, verifying that these fluctuations are gravity related.

Confocal laser endomicroscopy for brain tumor surgery: a milestone journey from microscopy to cellular surgery (Conference Presentation)

NASA Astrophysics Data System (ADS)

Charalampaki, Cleopatra

2017-02-01

The aim in brain tumor surgery is maximal tumor resection with minimal damage of normal neuronal tissue. Today diagnosis of tumor and definition of tumor borders intraoperatively is based on various visualization methods as well as on the histopathologic examination of a limited number of biopsy specimens via frozen sections. Unfortunately, intraoperative histopathology bears several shortcomings, and many biopsies are inconclusive. Therefore, the desirable treatment could be to have the ability to identify intraoperative cellular structures, and differentiate tumor from normal functional brain tissue on a cellular level. To achieve this goal new technological equipment integrated with new surgical concepts is needed.Confocal Laser Endomicroscopy (CLE) is an imaging technique which provides microscopic information of tissue in real-time. We are able to use these technique to perform intraoperative "optical biopsies" in bringing the microscope inside to the patients brain through miniaturized fiber-optic probes, and allow real-time histopathology. In our knowledge we are worldwide the only one neurosurgical group using CLE intraoperative for brain tumor surgery. We can detect and characterize intraoperative tumor cells, providing immediate online diagnosis without the need for frozen sections. It also provides delineation of borders between tumor and normal tissue on a cellular level, making surgical margins more accurate than ever before. The applications of CLE-assisted neurosurgery help to accurate the therapy by extending the resection borders and protecting the functionality of normal brain tissue in critical eloquent areas.

[The blood glucose value not necessarily indicates correctly the cellular metabolic state].

PubMed

Simon, Kornél; Wittmann, István

2017-03-01

In clinical recommendations the normalized blood glucose level is declared as the main target in therapy of diabetes mellitus, i.e. the achievement of euglycemia is the main therapeutic goal. This approach suggests, that the normal blood glucose value is the marker of the normal carbohydrate metabolism (eumetabolism), and vice versa: hyperglycemia is associated with abnormal metabolism (dysmetabolism). However the question arises, whether identical blood glucose values do reflect the same intracellular biochemical mechanisms? On the basis of data published in the literature authors try to answer these questions by studying the relations between the short/longterm blood glucose level and the cellular metabolism in different clinical settings characterized by divergent pathophysiological parameters. The correlations between blood glucose level and cellular metabolism in development of micro-, and macroangiopathy, in the breakthrough phenomenon, as well as during administration of metabolic promoters, the discrepancies of relation between blood glucose values and cellular metabolism in type 1, and type 2 diabetes mellitus, furthermore association between blood glucose value and myocardial metabolism in acute and chronic stress were analyzed. Authors conclude, that the actual blood glucose values reveal the actual cellular metabolism in a very variable manner: neither euglycemia does mandatorily indicate eumetabolism (balance of cellular energy production), nor hyperglycemia is necessarily a marker of abnormal metabolic state (dept of cellular energy production). Moreover, at the same actual blood glucose level both the metabolic efficacy of the same organ may sharply vary, and the intracellular biochemical machinery could also be very different. In case of the very same longterm blood glucose level the metabolic state of the different organs could be very variable: some organs show an energetically balanced metabolism, while others produce a significant deficit. These inconsistencies between blood glucose level and cellular metabolism can be explained by the fact, that blood glucose value is a transport parameter, reflecting the actual steady state of glucose transport from the carbohydrate pools into the blood, and that from the blood into the tissues. Without knowing the speed of these transports of opposite direction, the blood glucose value per se can not reveal the quantitative and qualitative characteristics of cellular metabolism. Orv. Hetil., 2017, 158(11), 409-417.

Asymmetric cellular memory in bacteria exposed to antibiotics.

PubMed

Mathis, Roland; Ackermann, Martin

2017-03-09

The ability to form a cellular memory and use it for cellular decision-making could help bacteria to cope with recurrent stress conditions. We analyzed whether bacteria would form a cellular memory specifically if past events are predictive of future conditions. We worked with the asymmetrically dividing bacterium Caulobacter crescentus where past events are expected to only be informative for one of the two cells emerging from division, the sessile cell that remains in the same microenvironment and does not migrate. Time-resolved analysis of individual cells revealed that past exposure to low levels of antibiotics increases tolerance to future exposure for the sessile but not for the motile cell. Using computer simulations, we found that such an asymmetry in cellular memory could be an evolutionary response to situations where the two cells emerging from division will experience different future conditions. Our results raise the question whether bacteria can evolve the ability to form and use cellular memory conditionally in situations where it is beneficial.

Two different mechanisms associated with ripple-like oscillations (100-250 Hz) in the human epileptic subiculum in vitro

PubMed Central

Alvarado-Rojas, C; Huberfeld, G; Baulac, M; Clemenceau, S; Charpier, S; Miles, R; Menendez de la Prida, L; Le Van Quyen, M

2015-01-01

Transient high-frequency oscillations (150-600 Hz) in local field potential generated by human hippocampal and parahippocampal areas have been related to both physiological and pathological processes. The cellular basis and effects of normal and abnormal forms of high-frequency oscillations (HFO) has been controversial. Here, we searched for HFOs in slices of the subiculum prepared from human hippocampal tissue resected for treatment of pharmacoresistant epilepsy. HFOs occurred spontaneously in extracellular field potentials during interictal discharges (IID) and also during pharmacologically induced preictal discharges (PID) preceding ictal-like events. While most of these events might be considered pathological since they invaded the fast ripple band (>250 Hz), others were spectrally similar to physiological ripples (150-250 Hz). Do similar cellular mechanisms underly IID-ripples and PID-ripples? Are ripple-like oscillations a valid proxy of epileptogenesis in human TLE? With combined intra- or juxta-cellular and extracellular recordings, we showed that, despite overlapping spectral components, ripple-like IID and PID oscillations were associated with different cellular and synaptic mechanisms. IID-ripples were associated with rhythmic GABAergic and glutamatergic synaptic potentials with moderate neuronal firing. In contrast, PID-ripples were associated with depolarizing synaptic inputs frequently reaching the threshold for bursting in most cells. Thus ripple-like oscillations (100-250 Hz) in the human epileptic hippocampus are associated with different mechanisms for synchrony reflecting distinct dynamic changes in inhibition and excitation during interictal and pre-ictal states. PMID:25448920

The Calcium-Sensing Receptor and Integrins in Cellular Differentiation and Migration

PubMed Central

Tharmalingam, Sujeenthar; Hampson, David R.

2016-01-01

The calcium-sensing receptor (CaSR) is a widely expressed homodimeric G-protein coupled receptor structurally related to the metabotropic glutamate receptors and GPRC6A. In addition to its well characterized role in maintaining calcium homeostasis and regulating parathyroid hormone release, evidence has accumulated linking the CaSR with cellular differentiation and migration, brain development, stem cell engraftment, wound healing, and tumor growth and metastasis. Elevated expression of the CaSR in aggressive metastatic tumors has been suggested as a potential novel prognostic marker for predicting metastasis, especially to bone tissue where extracellular calcium concentrations may be sufficiently high to activate the receptor. Recent evidence supports a model whereby CaSR-mediated activation of integrins promotes cellular migration. Integrins are single transmembrane spanning heterodimeric adhesion receptors that mediate cell migration by binding to extracellular matrix proteins. The CaSR has been shown to form signaling complexes with the integrins to facilitate both the movement and differentiation of cells, such as neurons during normal brain development and tumor cells under pathological circumstances. Thus, CaSR/integrin complexes may function as a universal cell migration or homing complex. Manipulation of this complex may be of potential interest for treating metastatic cancers, and for developmental disorders pertaining to aberrant neuronal migration. PMID:27303307

Integrated biocircuits: engineering functional multicellular circuits and devices.

PubMed

Prox, Jordan; Smith, Tory; Holl, Chad; Chehade, Nick; Guo, Liang

2018-04-01

Implantable neurotechnologies have revolutionized neuromodulatory medicine for treating the dysfunction of diseased neural circuitry. However, challenges with biocompatibility and lack of full control over neural network communication and function limits the potential to create more stable and robust neuromodulation devices. Thus, we propose a platform technology of implantable and programmable cellular systems, namely Integrated Biocircuits, which use only cells as the functional components of the device. We envision the foundational principles for this concept begins with novel in vitro platforms used for the study and reconstruction of cellular circuitry. Additionally, recent advancements in organoid and 3D culture systems account for microenvironment factors of cytoarchitecture to construct multicellular circuits as they are normally formed in the brain. We explore the current state of the art of these platforms to provide knowledge of their advancements in circuit fabrication and identify the current biological principles that could be applied in designing integrated biocircuit devices. We have highlighted the exemplary methodologies and techniques of in vitro circuit fabrication and propose the integration of selected controllable parameters, which would be required in creating suitable biodevices. We provide our perspective and propose new insights into the future of neuromodulaion devices within the scope of living cellular systems that can be applied in designing more reliable and biocompatible stimulation-based neuroprosthetics.

Integrated biocircuits: engineering functional multicellular circuits and devices

NASA Astrophysics Data System (ADS)

Prox, Jordan; Smith, Tory; Holl, Chad; Chehade, Nick; Guo, Liang

2018-04-01

Objective. Implantable neurotechnologies have revolutionized neuromodulatory medicine for treating the dysfunction of diseased neural circuitry. However, challenges with biocompatibility and lack of full control over neural network communication and function limits the potential to create more stable and robust neuromodulation devices. Thus, we propose a platform technology of implantable and programmable cellular systems, namely Integrated Biocircuits, which use only cells as the functional components of the device. Approach. We envision the foundational principles for this concept begins with novel in vitro platforms used for the study and reconstruction of cellular circuitry. Additionally, recent advancements in organoid and 3D culture systems account for microenvironment factors of cytoarchitecture to construct multicellular circuits as they are normally formed in the brain. We explore the current state of the art of these platforms to provide knowledge of their advancements in circuit fabrication and identify the current biological principles that could be applied in designing integrated biocircuit devices. Main results. We have highlighted the exemplary methodologies and techniques of in vitro circuit fabrication and propose the integration of selected controllable parameters, which would be required in creating suitable biodevices. Significance. We provide our perspective and propose new insights into the future of neuromodulaion devices within the scope of living cellular systems that can be applied in designing more reliable and biocompatible stimulation-based neuroprosthetics.

Cellular and Animal Studies: Insights into Pathophysiology and Therapy of PCOS.

PubMed

Indran, Inthrani Raja; Lee, Bao Hui; Yong, Eu-Leong

2016-11-01

Basic science studies have advanced our understanding of the role of key enzymes in the steroidogenesis pathway and those that affect the pathophysiology of PCOS. Studies with ovarian theca cells taken from women with PCOS have demonstrated increased androgen production due to increased CYP17A1 and HSD3B2 enzyme activities. Furthermore, overexpression of DENND1A variant 2 in normal theca cells resulted in a PCOS phenotype with increased androgen production. Notably, cellular steroidogenesis models have facilitated the understanding of the mechanistic effects of pharmacotherapies, including insulin sensitizers (e.g., pioglitazone and metformin) used for the treatment of insulin resistance in PCOS, on androgen production. In addition, animal models of PCOS have provided a critical platform to study the effects of therapeutic agents in a manner closer to the physiological state. Indeed, recent breakthroughs have demonstrated that natural derivatives such as the dietary medium-chain fatty acid decanoic acid (DA) can restore estrous cyclicity and lower androgen levels in an animal model of PCOS, thus laying the platform for novel therapeutic developments in PCOS. This chapter reviews the current understanding on the pathways modulating androgen biosynthesis, and the cellular and animal models that form the basis for preclinical research in PCOS, and sets the stage for clinical research. Copyright © 2016. Published by Elsevier Ltd.

Biosynthetic hydrogels--studies on chemical and physical characteristics on long-term cellular response for tissue engineering.

PubMed

Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

2014-07-01

Biosynthetic hydrogels can meet the drawbacks caused by natural and synthetic ones for biomedical applications. In the current article we present a novel biosynthetic alginate-poly(propylene fumarate) copolymer based chemically crosslinked hydrogel scaffolds for cardiac tissue engineering applications. Partially crosslinked PA hydrogel and fully cross linked PA-A hydrogel scaffolds were prepared. The influence of chemical and physical (morphology and architecture of hydrogel) characteristics on the long term cellular response was studied. Both these hydrogels were cytocompatible and showed no genotoxicity upon contact with fibroblast cells. Both PA and PA-A were able to resist deleterious effects of reactive oxygen species and sustain the viability of L929 cells. The hydrogel incubated oxidative stress induced cells were capable of maintaining the intra cellular reduced glutathione (GSH) expression to the normal level confirmed their protective effect. Relatively the PA hydrogel was found to be unstable in the cell culture medium. The PA-A hydrogel was able to withstand appreciable cyclic stretching. The cyclic stretching introduced complex macro and microarchitectural features with interconnected pores and more structured bound water which would provide long-term viability of around 250% after the 24th day of culture. All these qualities make PA-A hydrogel form a potent candidate for cardiac tissue engineering. © 2013 Wiley Periodicals, Inc.

Intracellular transport of fat-soluble vitamins A and E.

PubMed

Kono, Nozomu; Arai, Hiroyuki

2015-01-01

Vitamins are compounds that are essential for the normal growth, reproduction and functioning of the human body. Of the 13 known vitamins, vitamins A, D, E and K are lipophilic compounds and are therefore called fat-soluble vitamins. Because of their lipophilicity, fat-soluble vitamins are solubilized and transported by intracellular carrier proteins to exert their actions and to be metabolized properly. Vitamin A and its derivatives, collectively called retinoids, are solubilized by intracellular retinoid-binding proteins such as cellular retinol-binding protein (CRBP), cellular retinoic acid-binding protein (CRABP) and cellular retinal-binding protein (CRALBP). These proteins act as chaperones that regulate the metabolism, signaling and transport of retinoids. CRALBP-mediated intracellular retinoid transport is essential for vision in human. α-Tocopherol, the main form of vitamin E found in the body, is transported by α-tocopherol transfer protein (α-TTP) in hepatic cells. Defects of α-TTP cause vitamin E deficiency and neurological disorders in humans. Recently, it has been shown that the interaction of α-TTP with phosphoinositides plays a critical role in the intracellular transport of α-tocopherol and is associated with familial vitamin E deficiency. In this review, we summarize the mechanisms and biological significance of the intracellular transport of vitamins A and E. © 2014 The Authors. Traffic published by John Wiley & Sons Ltd.

Murine Electrophysiological Models of Cardiac Arrhythmogenesis

PubMed Central

2016-01-01

Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias. PMID:27974512

Phase separation and the formation of cellular bodies

NASA Astrophysics Data System (ADS)

Xu, Bin; Broedersz, Chase P.; Meir, Yigal; Wingreen, Ned S.

Cellular bodies in eukaryotic cells spontaneously assemble to form cellular compartments. Among other functions, these bodies carry out essential biochemical reactions. Cellular bodies form micron-sized structures, which, unlike canonical cell organelles, are not surrounded by membranes. A recent in vitro experiment has shown that phase separation of polymers in solution can explain the formation of cellular bodies. We constructed a lattice-polymer model to capture the essential mechanism leading to this phase separation. We used both analytical and numerical tools to predict the phase diagram of a system of two interacting polymers, including the concentration of each polymer type in the condensed and dilute phase.

[Effect of electroacupuncture on cellular structure of hippocampus in splenic asthenia pedo-rats].

PubMed

Yang, Zhuo-xin; Zhuo, Yuan-yuan; Yu, Hai-bo; Wang, Ning

2010-02-01

To observe the effect of electroacupuncture (EA) on hippocampal structure in splenic asthenia pedo-rats. A total of 15 SD male rats were randomly assigned to normal control group (n=5), model group (n=5) and EA group (n=5). Splenic asthenic syndrome model was established by intragastric administration of rhubarb and intraperitoneal injection of Reserpine for 14 d. EA (1 mA, 3 Hz/iS Hz) was applied to bilateral "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) for 20 mm, once a day for 14 days. The cellular structure of hippocampus was observed by light microscope and transmission electron microscope. Optical microscopic observation showed that in normal control group, the cellular nucleus was distinct, and the granular cell layer well-arranged and tight. In model group, the intracellular space was widened, and the granular cell layer was out of order in the arrangement. In EA group, the celluldr nucleus and the granular cell layer were nearly normal. Results of the electronic microscope showed that cells in model group had a karyopyknosis with irregular appearance and clear incisure, and some of them presented dissolving and necrotic phenomena; and those in EA group were milder in injury, had nearly-normal nucleus with visible nucleoli and relatively-intact nuclear membrane. Regarding the cellular plasma, in comparison with rich normal organelles of control group, the mitochondria in model group were swelling, with vague, dissolved and broken cristae, while in EA group, majority of the organelles were well-kept, and slightly dissolved mitochondrial cristae found. In regard to the synaptic structure, in comparison with control group, synaptic apomorphosis and swelling mitochondria were found in model group While in EA group, milder swelling and hydropic degeneration were seen. Different from the distinct pre- and post-synaptic membrane and synaptic vesicles of control group, while those in EA group were nearly-normal. electroacupunture can effectively relieve splenasthenic syndrome induced pathohistological changes of neurons of the hippocampus in the rat.

Arctigenin preferentially induces tumor cell death under glucose deprivation by inhibiting cellular energy metabolism.

PubMed

Gu, Yuan; Qi, Chunting; Sun, Xiaoxiao; Ma, Xiuquan; Zhang, Haohao; Hu, Lihong; Yuan, Junying; Yu, Qiang

2012-08-15

Selectively eradicating cancer cells with minimum adverse effects on normal cells is a major challenge in the development of anticancer therapy. We hypothesize that nutrient-limiting conditions frequently encountered by cancer cells in poorly vascularized solid tumors might provide an opportunity for developing selective therapy. In this study, we investigated the function and molecular mechanisms of a natural compound, arctigenin, in regulating tumor cell growth. We demonstrated that arctigenin selectively promoted glucose-starved A549 tumor cells to undergo necrosis by inhibiting mitochondrial respiration. In doing so, arctigenin elevated cellular level of reactive oxygen species (ROS) and blocked cellular energy metabolism in the glucose-starved tumor cells. We also demonstrated that cellular ROS generation was caused by intracellular ATP depletion and played an essential role in the arctigenin-induced tumor cell death under the glucose-limiting condition. Furthermore, we combined arctigenin with the glucose analogue 2-deoxyglucose (2DG) and examined their effects on tumor cell growth. Interestingly, this combination displayed preferential cell-death inducing activity against tumor cells compared to normal cells. Hence, we propose that the combination of arctigenin and 2DG may represent a promising new cancer therapy with minimal normal tissue toxicity. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

Galactose-depleted xyloglucan is dysfunctional and leads to dwarfism in Arabidopsis.

PubMed

Kong, Yingzhen; Peña, Maria J; Renna, Luciana; Avci, Utku; Pattathil, Sivakumar; Tuomivaara, Sami T; Li, Xuemei; Reiter, Wolf-Dieter; Brandizzi, Federica; Hahn, Michael G; Darvill, Alan G; York, William S; O'Neill, Malcolm A

2015-04-01

Xyloglucan is a polysaccharide that has important roles in the formation and function of the walls that surround growing land plant cells. Many of these plants synthesize xyloglucan that contains galactose in two different side chains (L and F), which exist in distinct molecular environments. However, little is known about the contribution of these side chains to xyloglucan function. Here, we show that Arabidopsis (Arabidopsis thaliana) mutants devoid of the F side chain galactosyltransferase MURUS3 (MUR3) form xyloglucan that lacks F side chains and contains much less galactosylated xylose than its wild-type counterpart. The galactose-depleted xyloglucan is dysfunctional, as it leads to mutants that are dwarfed with curled rosette leaves, short petioles, and short inflorescence stems. Moreover, cell wall matrix polysaccharides, including xyloglucan and pectin, are not properly secreted and instead accumulate within intracellular aggregates. Near-normal growth is restored by generating mur3 mutants that produce no detectable amounts of xyloglucan. Thus, cellular processes are affected more by the presence of the dysfunctional xyloglucan than by eliminating xyloglucan altogether. To identify structural features responsible for xyloglucan dysfunction, xyloglucan structure was modified in situ by generating mur3 mutants that lack specific xyloglucan xylosyltransferases (XXTs) or that overexpress the XYLOGLUCAN L-SIDE CHAIN GALACTOSYLTRANSFERASE2 (XLT2) gene. Normal growth was restored in the mur3-3 mutant overexpressing XLT2 and in mur3-3 xxt double mutants when the dysfunctional xyloglucan was modified by doubling the amounts of galactosylated side chains. Our study assigns a role for galactosylation in normal xyloglucan function and demonstrates that altering xyloglucan side chain structure disturbs diverse cellular and physiological processes. © 2015 American Society of Plant Biologists. All Rights Reserved.

Efficient generation of biliary epithelial cells from rabbit intrahepatic bile duct by Y-27632 and Matrigel.

PubMed

Jin, Lifang; Ji, Shaohui; Sun, Aijing

2013-06-01

Efficient culture of primary biliary epithelial cells (BECs) from adult liver is useful for both experimental studies and clinical applications of tissue engineering. However, an effective culture system for long-term proliferation of adult BECs is still unachieved. Laboratory rabbit has been used in a large number of studies; however, there are no reports of BECs from normal adult rabbit. As little as 5 g of normal rabbit liver tissue were minced, digested, and then clonally cultured in medium containing FBS and ITS. Cells were characterized by cell morphology, immunoassaying, and growth rate assay. Different combination of growth factors and substrates, including Y-27632 and Matrigel, were employed to assess their effect on cell proliferation. In the primary culture, the BECs cellular sheets consisting of cuboidal cells, as well as fibroblast-like cells and other hepatic cells, emerged with time of culture. The BECs cellular sheets were then manually split into cells clumps for further characterization. The subcultured cells had typical cell morphology of cholangiocytes, expressed the specific markers of BECs, including GGT, cytokeratin (CK18), and CK19, and possessed the capacity to form duct-like structure in three-dimensional Matrigel. Y-27632 and Matrigel-treated BECs had a steady growth rate as well as colony-formation capacity. The BECs were maintained in Y-27632 and Matrigel culture system for more than 3 mo. This is the first example, to our knowledge, of the successful culture of BECs from normal adult rabbit liver. Furthermore, our results indicate that treatment of BECs with Y-27632 and Matrigel is a simple method for efficient output of BECs.

Controlled expression of nif and isc iron-sulfur protein maturation components reveals target specificity and limited functional replacement between the two systems.

PubMed

Dos Santos, Patricia C; Johnson, Deborah C; Ragle, Brook E; Unciuleac, Mihaela-Carmen; Dean, Dennis R

2007-04-01

The nitrogen-fixing organism Azotobacter vinelandii contains at least two systems that catalyze formation of [Fe-S] clusters. One of these systems is encoded by nif genes, whose products supply [Fe-S] clusters required for maturation of nitrogenase. The other system is encoded by isc genes, whose products are required for maturation of [Fe-S] proteins that participate in general metabolic processes. The two systems are similar in that they include an enzyme for the mobilization of sulfur (NifS or IscS) and an assembly scaffold (NifU or IscU) upon which [Fe-S] clusters are formed. Normal cellular levels of the Nif system, which supplies [Fe-S] clusters for the maturation of nitrogenase, cannot also supply [Fe-S] clusters for the maturation of other cellular [Fe-S] proteins. Conversely, when produced at the normal physiological levels, the Isc system cannot supply [Fe-S] clusters for the maturation of nitrogenase. In the present work we found that such target specificity for IscU can be overcome by elevated production of NifU. We also found that NifU, when expressed at normal levels, is able to partially replace the function of IscU if cells are cultured under low-oxygen-availability conditions. In contrast to the situation with IscU, we could not establish conditions in which the function of IscS could be replaced by NifS. We also found that elevated expression of the Isc components, as a result of deletion of the regulatory iscR gene, improved the capacity for nitrogen-fixing growth of strains deficient in either NifU or NifS.

Mannan oligosaccharide requires functional ETC and TLR for biological radiation protection to normal cells.

PubMed

Sanguri, Sweta; Gupta, Damodar

2018-06-27

Low LET Ionizing radiation is known to alter intracellular redox balance by inducing free radical generation, which may cause oxidative modification of various cellular biomolecules. The extent of biomolecule-modifications/ damages and changes in vital processes (viz. cellular homeostasis, inter-/intra-cellular signaling, mitochondrial physiology/dynamics antioxidant defence systems) are crucial which in turn determine fate of cells. In the present study, we expended TLR expressing (normal/ transformed) and TLR null cells; and we have shown that mannan pretreatment in TLR expressing normal cells offers survival advantage against lethal doses of ionizing radiation. On the contrary, mannan pretreatment does not offer any protection against radiation to TLR null cells, NKE ρ° cells and transformed cells. In normal cells, abrupt decrease in mitochondrial membrane potential and endogenous ROS levels occurs following treatment with mannan. We intend to irradiate mannan-pretreated cells at a specific stage of perturbed mitochondrial functioning and ROS levels to comprehend if mannan pretreatment offers any survival advantage against radiation exposure to cells. Interestingly, pre-irradiation treatment of cells with mannan activates NFκB, p38 and JNK, alters mitochondrial physiology, increases expression of Cu/ZnSOD and MnSOD, minimizes oxidation of mitochondrial phospholipids and offers survival advantage in comparison to irradiated group, in TLR expressing normal cells. The study demonstrates that TLR and mitochondrial ETC functions are inevitable in radio-protective efficacy exhibited by mannan.

A Decade of Boon or Burden: What Has the CHIP Ever Done for Cellular Protein Quality Control Mechanism Implicated in Neurodegeneration and Aging?

PubMed Central

Joshi, Vibhuti; Amanullah, Ayeman; Upadhyay, Arun; Mishra, Ribhav; Kumar, Amit; Mishra, Amit

2016-01-01

Cells regularly synthesize new proteins to replace old and abnormal proteins for normal cellular functions. Two significant protein quality control pathways inside the cellular milieu are ubiquitin proteasome system (UPS) and autophagy. Autophagy is known for bulk clearance of cytoplasmic aggregated proteins, whereas the specificity of protein degradation by UPS comes from E3 ubiquitin ligases. Few E3 ubiquitin ligases, like C-terminus of Hsc70-interacting protein (CHIP) not only take part in protein quality control pathways, but also plays a key regulatory role in other cellular processes like signaling, development, DNA damage repair, immunity and aging. CHIP targets misfolded proteins for their degradation through proteasome, as well as autophagy; simultaneously, with the help of chaperones, it also regulates folding attempts for misfolded proteins. The broad range of CHIP substrates and their associations with multiple pathologies make it a key molecule to work upon and focus for future therapeutic interventions. E3 ubiquitin ligase CHIP interacts and degrades many protein inclusions formed in neurodegenerative diseases. The presence of CHIP at various nodes of cellular protein-protein interaction network presents this molecule as a potential candidate for further research. In this review, we have explored a wide range of functionality of CHIP inside cells by a detailed presentation of its co-chaperone, E3 and E4 enzyme like functions, with central focus on its protein quality control roles in neurodegenerative diseases. We have also raised many unexplored but expected fundamental questions regarding CHIP functions, which generate hopes for its future applications in research, as well as drug discovery. PMID:27757073

Biochemical analyses are instrumental in identifying the impact of mutations on holo and/or apo-forms and on the region(s) of alanine:glyoxylate aminotransferase variants associated with Primary Hyperoxaluria Type I☆

PubMed Central

Oppici, Elisa; Montioli, Riccardo; Lorenzetto, Antonio; Bianconi, Silvia; Borri Voltattorni, Carla; Cellini, Barbara

2012-01-01

Primary Hyperoxaluria Type I (PH1) is a disorder of glyoxylate metabolism caused by mutations in the human AGXT gene encoding liver peroxisomal alanine:glyoxylate aminotransferase (AGT), a pyridoxal 5′-phosphate (PLP) dependent enzyme. Previous investigations highlighted that, although PH1 is characterized by a significant variability in terms of enzymatic phenotype, the majority of the pathogenic variants are believed to share both structural and functional defects, as mainly revealed by data on AGT activity and expression level in crude cellular extracts. However, the knowledge of the defects of the AGT variants at a protein level is still poor. We therefore performed a side-by-side comparison between normal AGT and nine purified recombinant pathogenic variants in terms of catalytic activity, coenzyme binding mode and affinity, spectroscopic features, oligomerization, and thermal stability of both the holo- and apo-forms. Notably, we chose four variants in which the mutated residues are located in the large domain of AGT either within the active site and interacting with the coenzyme or in its proximity, and five variants in which the mutated residues are distant from the active site either in the large or in the small domain. Overall, this integrated analysis of enzymatic activity, spectroscopic and stability information is used to (i) reassess previous data obtained with crude cellular extracts, (ii) establish which form(s) (i.e. holoenzyme and/or apoenzyme) and region(s) (i.e. active site microenvironment, large and/or small domain) of the protein are affected by each mutation, and (iii) suggest the possible therapeutic approach for patients bearing the examined mutations. PMID:22018727

Biochemical analyses are instrumental in identifying the impact of mutations on holo and/or apo-forms and on the region(s) of alanine:glyoxylate aminotransferase variants associated with primary hyperoxaluria type I.

PubMed

Oppici, Elisa; Montioli, Riccardo; Lorenzetto, Antonio; Bianconi, Silvia; Borri Voltattorni, Carla; Cellini, Barbara

2012-01-01

Primary Hyperoxaluria Type I (PH1) is a disorder of glyoxylate metabolism caused by mutations in the human AGXT gene encoding liver peroxisomal alanine:glyoxylate aminotransferase (AGT), a pyridoxal 5'-phosphate (PLP) dependent enzyme. Previous investigations highlighted that, although PH1 is characterized by a significant variability in terms of enzymatic phenotype, the majority of the pathogenic variants are believed to share both structural and functional defects, as mainly revealed by data on AGT activity and expression level in crude cellular extracts. However, the knowledge of the defects of the AGT variants at a protein level is still poor. We therefore performed a side-by-side comparison between normal AGT and nine purified recombinant pathogenic variants in terms of catalytic activity, coenzyme binding mode and affinity, spectroscopic features, oligomerization, and thermal stability of both the holo- and apo-forms. Notably, we chose four variants in which the mutated residues are located in the large domain of AGT either within the active site and interacting with the coenzyme or in its proximity, and five variants in which the mutated residues are distant from the active site either in the large or in the small domain. Overall, this integrated analysis of enzymatic activity, spectroscopic and stability information is used to (i) reassess previous data obtained with crude cellular extracts, (ii) establish which form(s) (i.e. holoenzyme and/or apoenzyme) and region(s) (i.e. active site microenvironment, large and/or small domain) of the protein are affected by each mutation, and (iii) suggest the possible therapeutic approach for patients bearing the examined mutations. Copyright © 2011 Elsevier Inc. All rights reserved.

Cell Signaling and Neurotoxicity: 3H-Arachidonic acid release (Phospholipase A2) in cerebellar granule neurons

EPA Science Inventory

Cell signaling is a complex process which controls basic cellular activities and coordinates actions to maintain normal cellular homeostasis. Alterations in signaling processes have been associated with neurological diseases such as Alzheimer's and cerebellar ataxia, as well as, ...

Recent Advances in Type-2-Cell-Mediated Immunity: Insights from Helminth Infection.

PubMed

Harris, Nicola L; Loke, P'ng

2017-12-19

Type-2-cell-mediated immune responses play a critical role in mediating both host-resistance and disease-tolerance mechanisms during helminth infections. Recently, type 2 cell responses have emerged as major regulators of tissue repair and metabolic homeostasis even under steady-state conditions. In this review, we consider how studies of helminth infection have contributed toward our expanding cellular and molecular understanding of type-2-cell-mediated immunity, as well as new areas such as the microbiome. By studying how these successful parasites form chronic infections without overt pathology, we are gaining additional insights into allergic and inflammatory diseases, as well as normal physiology. Copyright © 2017 Elsevier Inc. All rights reserved.

The molecular and cellular response of normal and progressed human bronchial epithelial cells to HZE particles

NASA Astrophysics Data System (ADS)

Story, Michael; Ding, Liang-Hao; Minna, John; Park, Seong-mi; Larsen, Jill

We have used a model of non-oncogenically immortalized normal human bronchial epithelial cells to determine the response of such cells to particles found outside the protection of the earth’s electromagnetic field. We have identified an enhanced frequency of cellular transformation, as measured by growth in soft agar, for both 56Fe and 28Si (1 GeV/n) that is maximal (4-6 fold) at 0.25 Gy and 0.40 Gy, respectively. At 4 months post-irradiation 38 individual soft agar clones were isolated. These clones were characterized extensively for cellular and molecular changes. Gene expression analysis suggested that these clones had down-regulated several genes associated with anti-oxidant pathways including GLS2, GPX1 and 4, SOD2, PIG3, and NQO1 amongst others. As a result, many of these transformed clones were exposed to high levels of intracellular radical oxygen species (ROS), although there appeared not to be any enhanced mitochondrial ROS. DNA repair pathways associated with ATM/ATR signaling were also upregulated. However, these transformants do not develop into tumors when injected into immune-compromised mice, suggesting that they have not progressed sufficiently to become oncogenic. Therefore we chose 6 soft agar clones for continuous culture for an additional 14 months. Amongst the 6 clones, only one clone showed any significant change in phenotype. Clone 3kt-ff.2a, propagated for 18 months, were 2-fold more radioresistant, had a shortened doubling time and the background rate of transformation more than doubled. Furthermore, the morphology of transformed clones changed. Clones from this culture are being compared to the original clone as well as the parental HBEC3KT and will be injected into immune-compromised mice for oncogenic potential. Oncogenically progressed HBECs, HBEC3KT cells that overexpress a mutant RAS gene and where p53 has been knocked down, designated HBEC3KTR53, responded quite differently to HZE particle exposure. First, these cells are more radioresistant to all radiations used when compared to the parental cell line HBEC3KT. Furthermore, within days of their exposure to low and high LET radiations they exhibit enhanced cellular transformation over the parental cells. Moreover, HZE radiations are many fold more effective at initiating cellular transformation. Gene expression analysis identified several pathways that support oncogenic growth as overrepresented in the progressed cells. With continual culture some clones undergo epithelial to mesenchymal transition, change morphology and express markers associated with EMT. And, at least one clone is oncogenic forming highly aggressive tumors in an immune compromised mouse strain. It is important to note that HBEC3KTR53 cells will not form tumors in mice, however, this irradiated clone has moved through the multi-step process of carcinogenesis. We are now examining the molecular alterations that led to oncogenesis in this clone.

[The Steel factor].

PubMed

Cáceres-Cortés, J R

1997-01-01

Mice bearing mutations at either of two loci, dominant White spotting(W) or Steel(Sl), exhibit development defects in hematopoietic, melanocytic and germ cells. Genetics studies have shown that the SI locus encodes the Steel factor (SF), which is the ligand for the tyrosine kinase receptor c-kit, the product of the W locus. SF is synthesized in membrane-bound form and can be processed to produce a soluble form. Cell-cell interaction is important in the production of normal blood cells in vivo and in vitro and in the cellular expansion of leukemic cells. We discuss here how SF decreases the requirements in cell interaction for blast colony formation in acute myeloblastic leukemia (AML) and the presence of membrane-bound SF possibly contributes to the density-dependent growth of the AML blasts. We explain that SF is mainly a survival factor for hematopoietic cells, of little proliferative effect, which maintains CD34+ hematopoietic cells in an undifferentiated state. These properties would potentially allow the maintenance of hematopoietic cells in culture for the purpose of marrow purging or gene therapy. The activation of the c-kit signal transduction pathway may play a significant role in the development of many types of non-hematological malignancies by disrupting normal cell-cell interactions and allowing the growth of cancer cell populations. In summary, the properties of the SF indicate it has a role for survival signals during the process of normal differentiation, AML proliferation and in the maintenance of many c-kit+ tumors.

Breast cancer mitosis detection in histopathological images with spatial feature extraction

NASA Astrophysics Data System (ADS)

Albayrak, Abdülkadir; Bilgin, Gökhan

2013-12-01

In this work, cellular mitosis detection in histopathological images has been investigated. Mitosis detection is very expensive and time consuming process. Development of digital imaging in pathology has enabled reasonable and effective solution to this problem. Segmentation of digital images provides easier analysis of cell structures in histopathological data. To differentiate normal and mitotic cells in histopathological images, feature extraction step is very crucial step for the system accuracy. A mitotic cell has more distinctive textural dissimilarities than the other normal cells. Hence, it is important to incorporate spatial information in feature extraction or in post-processing steps. As a main part of this study, Haralick texture descriptor has been proposed with different spatial window sizes in RGB and La*b* color spaces. So, spatial dependencies of normal and mitotic cellular pixels can be evaluated within different pixel neighborhoods. Extracted features are compared with various sample sizes by Support Vector Machines using k-fold cross validation method. According to the represented results, it has been shown that separation accuracy on mitotic and non-mitotic cellular pixels gets better with the increasing size of spatial window.

A gene involved in control of human cellular senescence on human chromosome 1q

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hensler, P.J.; Pereira-Smith, O.M.; Annab, L.A.

1994-04-01

Normal cells in culture exhibit limited division potential and have been used as a model for cellular senescence. In contrast, tumor-derived or carcinogen- or virus-transformed cells are capable of indefinite division. Fusion of normal human diploid fibroblasts with immortal human cells yielded hybrids having limited life spans, indicating that cellular senescence was dominant. Fusions of various immortal human cell lines with each other led to the identification of four complementation groups for indefinite division. The purpose of this study was to determine whether human chromosome 1 could complement the recessive immortal defect of human cell lines assigned to one ofmore » the four complementation groups. Using microcell fusion, the authors introduced a single normal human chromosome 1 into immortal human cell lines representing the complementation groups and determined that it caused loss of proliferative potential of an osteosarcoma-derived cell line (TE85), a cytomegalovirus-transformed lung fibroblast cell line (CMV-Mj-HEL-1), and a Ki-ras[sup +]-transformed derivative of TE85 (143B TK[sup [minus

NAD(H) and NADP(H) Redox Couples and Cellular Energy Metabolism.

PubMed

Xiao, Wusheng; Wang, Rui-Sheng; Handy, Diane E; Loscalzo, Joseph

2018-01-20

The nicotinamide adenine dinucleotide (NAD + )/reduced NAD + (NADH) and NADP + /reduced NADP + (NADPH) redox couples are essential for maintaining cellular redox homeostasis and for modulating numerous biological events, including cellular metabolism. Deficiency or imbalance of these two redox couples has been associated with many pathological disorders. Recent Advances: Newly identified biosynthetic enzymes and newly developed genetically encoded biosensors enable us to understand better how cells maintain compartmentalized NAD(H) and NADP(H) pools. The concept of redox stress (oxidative and reductive stress) reflected by changes in NAD(H)/NADP(H) has increasingly gained attention. The emerging roles of NAD + -consuming proteins in regulating cellular redox and metabolic homeostasis are active research topics. The biosynthesis and distribution of cellular NAD(H) and NADP(H) are highly compartmentalized. It is critical to understand how cells maintain the steady levels of these redox couple pools to ensure their normal functions and simultaneously avoid inducing redox stress. In addition, it is essential to understand how NAD(H)- and NADP(H)-utilizing enzymes interact with other signaling pathways, such as those regulated by hypoxia-inducible factor, to maintain cellular redox homeostasis and energy metabolism. Additional studies are needed to investigate the inter-relationships among compartmentalized NAD(H)/NADP(H) pools and how these two dinucleotide redox couples collaboratively regulate cellular redox states and cellular metabolism under normal and pathological conditions. Furthermore, recent studies suggest the utility of using pharmacological interventions or nutrient-based bioactive NAD + precursors as therapeutic interventions for metabolic diseases. Thus, a better understanding of the cellular functions of NAD(H) and NADP(H) may facilitate efforts to address a host of pathological disorders effectively. Antioxid. Redox Signal. 28, 251-272.

Biochemical and Cellular Assessment of Acetabular Chondral Flaps Identified During Hip Arthroscopy.

PubMed

Hariri, Sanaz; Truntzer, Jeremy; Smith, Robert Lane; Safran, Marc R

2015-06-01

To analyze chondral flaps debrided during hip arthroscopy to determine their biochemical and cellular composition. Thirty-one full-thickness acetabular chondral flaps were collected during hip arthroscopy. Biochemical analysis was undertaken in 21 flaps from 20 patients, and cellular viability was determined in 10 flaps from 10 patients. Biochemical analysis included concentrations of (1) DNA (an indicator of chondrocyte content), (2) hydroxyproline (an indicator of collagen content), and (3) glycosaminoglycan (an indicator of chondrocyte biosynthesis). Higher values for these parameters indicated more healthy tissue. The flaps were examined to determine the percentage of viable chondrocytes. The percentage of acetabular chondral flap specimens that had concentrations within 1 SD of the mean values reported in previous normal cartilage studies was 38% for DNA, 0% for glycosaminoglycan, and 43% for hydroxyproline. The average cellular viability of our acetabular chondral flap specimens was 39% (SD, 14%). Only 2 of the 10 specimens had more than half the cells still viable. There was no correlation between (1) the gross examination of the joint or knowledge of the patient's demographic characteristics and symptoms and (2) biochemical properties and cell viability of the flap, with one exception: a degenerative appearance of the surrounding cartilage correlated with a higher hydroxyproline concentration. Although full-thickness acetabular chondral flaps can appear normal grossly, the biochemical properties and percentage of live chondrocytes in full-thickness chondral flaps encountered in hip arthroscopy show that this tissue is not normal. There has been recent interest in repairing chondral flaps encountered during hip arthroscopy. These data suggest that acetabular chondral flaps are not biochemically and cellularly normal. Although these flaps may still be valuable mechanically and/or as a scaffold in some conductive or inductive capacity, further study is required to assess the clinical benefit of repair. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Suppression of the PI3K subunit p85α delays embryoid body development and inhibits cell adhesion.

PubMed

Gurney, Susan M R; Forster, Peter; Just, Ursula; Schwanbeck, Ralf

2011-12-01

Phosphatidylinositol-3-kinases (PI3Ks) exert a variety of signaling functions in eukaryotes. We suppressed the PI3K regulatory subunit p85α using a small interfering RNA (Pik3r1 siRNA) and examined the effects on embryoid body (EB) development in hanging drop culture. We observed a 150% increase in the volume of the treated EBs within 24 h, compared to the negative controls. Fluorescence Activated Cell Sorting (FACS) assays showed that this increase in volume is not due to increased cellular proliferation. Instead, the increase in volume appears to be due to reduced cellular aggregation and adherence. This is further shown by our observation that 40% of treated EBs form twin instead of single EBs, and that they have a significantly reduced ability to adhere to culture dishes when plated. A time course over the first 96 h reveals that the impaired adherence is transient and explained by an initial 12-hour delay in EB development. Quantitative PCR expression analysis suggests that the adhesion molecule integrin-β1 (ITGB1) is transiently downregulated by the p85α suppression. In conclusion we found that suppressing p85α leads to a delay in forming compact EBs, accompanied by a transient inability of the EBs to undergo normal cell-cell and cell-substrate adhesion. Copyright © 2011 Wiley Periodicals, Inc.

Defining the cellular precursors to human breast cancer

PubMed Central

Keller, Patricia J.; Arendt, Lisa M.; Skibinski, Adam; Logvinenko, Tanya; Klebba, Ina; Dong, Shumin; Smith, Avi E.; Prat, Aleix; Perou, Charles M.; Gilmore, Hannah; Schnitt, Stuart; Naber, Stephen P.; Garlick, Jonathan A.; Kuperwasser, Charlotte

2012-01-01

Human breast cancers are broadly classified based on their gene-expression profiles into luminal- and basal-type tumors. These two major tumor subtypes express markers corresponding to the major differentiation states of epithelial cells in the breast: luminal (EpCAM+) and basal/myoepithelial (CD10+). However, there are also rare types of breast cancers, such as metaplastic carcinomas, where tumor cells exhibit features of alternate cell types that no longer resemble breast epithelium. Until now, it has been difficult to identify the cell type(s) in the human breast that gives rise to these various forms of breast cancer. Here we report that transformation of EpCAM+ epithelial cells results in the formation of common forms of human breast cancer, including estrogen receptor-positive and estrogen receptor-negative tumors with luminal and basal-like characteristics, respectively, whereas transformation of CD10+ cells results in the development of rare metaplastic tumors reminiscent of the claudin-low subtype. We also demonstrate the existence of CD10+ breast cells with metaplastic traits that can give rise to skin and epidermal tissues. Furthermore, we show that the development of metaplastic breast cancer is attributable, in part, to the transformation of these metaplastic breast epithelial cells. These findings identify normal cellular precursors to human breast cancers and reveal the existence of a population of cells with epidermal progenitor activity within adult human breast tissues. PMID:21940501

Intraperitoneal (188)Re-Liposome delivery switches ovarian cancer metabolism from glycolysis to oxidative phosphorylation and effectively controls ovarian tumour growth in mice.

PubMed

Shen, Yao An; Lan, Keng Li; Chang, Chih Hsien; Lin, Liang Ting; He, Chun Lin; Chen, Po Hung; Lee, Te Wei; Lee, Yi Jang; Chuang, Chi Mu

2016-05-01

Cancer stem cells exhibit distinctive cellular metabolism compared with the more differentiated counterparts or normal cells. We aimed to investigate the impact of a novel radionuclide anti-cancer agent (188)Re-Liposome on stemness markers' expression and cellular metabolism in an ovarian cancer model. A 2×2 factorial experiment was designed in which factor 1 represented the drug treatment comparing (188)Re-BMEDA, a free form of (188)Re, with (188)Re-Liposome, a nanoparticle-encapsulated form of (188)Re. Factor 2 represented the delivery route, comparing intravenous with intraperitoneal delivery. Intraperitoneal delivery of (188)Re-Liposome predominantly killed the CSCs-like cells in tumours and switched metabolism from glycolysis to oxidative phosphorylation. Further, intraperitoneal delivery of (188)Re-Liposome treatment was able to block epithelial-to-mesenchymal transition (EMT) and reactivate p53 function. Collectively, these molecular changes led to a striking tumour-killing effect. Radionuclides encapsulated in liposomes may represent a novel treatment for ovarian cancer when delivered intraperitoneally (a type of loco-regional delivery). In the future, this concept may be further extended for the treatment of several relevant cancers that have been proved to be suitable for loco-regional delivery of therapeutic agents, such as colon cancer, gastric cancer, and pancreatic cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Three-dimensional reconstruction of root cells and interdental cells in the rat inner ear by serial section scanning electron microscopy.

PubMed

Shodo, Ryusuke; Hayatsu, Manabu; Koga, Daisuke; Horii, Arata; Ushiki, Tatsuo

2017-01-01

In the cochlea, a high K + environment in the endolymph is essential for the maintenance of normal hearing function, and the transport of K + ions through gap junctions of the cochlear epithelium is thought to play an important role in endolymphatic homeostasis. The aim of the present study was to demonstrate the three-dimensional (3D) ultrastructure of spiral ligament root cells and interdental cells, which are located at both ends of the gap junction system of the cochlea epithelium. Serial semi-thin sections of plastic-embedded rat cochlea were mounted on glass slides, stained with uranyl acetate and lead citrate, and observed by scanning electron microscopy (SEM) using the backscattered electron (BSE) mode. 3D reconstruction of BSE images of serial sections revealed that the root cells were linked together to form a branched structure like an elaborate "tree root" in the spiral ligament. The interdental cells were also connected to each other, forming a comb-shaped cellular network with a number of cellular strands in the spiral limbus. Furthermore, TEM studies of ultra-thin sections revealed the rich presence of gap junctions in both root cells and interdental cells. These findings suggest the possibility that both root cells and interdental cells contribute to K + circulation as the end portion of the epithelial cell gap junction system of the cochlea.

Defects and Disorder in the Drosophila Eye

NASA Astrophysics Data System (ADS)

Kim, Sangwoo; Carthew, Richard; Hilgenfeldt, Sascha

Cell division and differentiation tightly control the regular pattern in the normal eye of the Drosophila fruit fly while certain genetic mutations introduce disorder in the form of topological defects. Analyzing data from pupal retinas, we develop a model based on Voronoi construction that explains the defect statistics as a consequence of area variation of individual facets (ommatidia). The analysis reveals a previously unknown systematic long-range area variation that spans the entire eye, with distinct effects on topological disorder compared to local fluctuations. The internal structure of the ommatidia and the stiffness of their interior cells also plays a crucial role in the defect generation. Accurate predictions of the correlation between the area variation and the defect density in both normal and mutant animals are obtained without free parameters. This approach can potentially be applied to cellular systems in many other contexts to identify size-topology correlations near the onset of symmetry breaking. This work has been supported by the NIH (GM098077) and the NSF (Grant No. 1504301).

HAMLET kills tumor cells by apoptosis: structure, cellular mechanisms, and therapy.

PubMed

Gustafsson, Lotta; Hallgren, Oskar; Mossberg, Ann-Kristin; Pettersson, Jenny; Fischer, Walter; Aronsson, Annika; Svanborg, Catharina

2005-05-01

New cancer treatments should aim to destroy tumor cells without disturbing normal tissue. HAMLET (human alpha-lactalbumin made lethal to tumor cells) offers a new molecular approach to solving this problem, because it induces apoptosis in tumor cells but leaves normal differentiated cells unaffected. After partial unfolding and binding to oleic acid, alpha-lactalbumin forms the HAMLET complex, which enters tumor cells and freezes their metabolic machinery. The cells proceed to fragment their DNA, and they disintegrate with apoptosis-like characteristics. HAMLET kills a wide range of malignant cells in vitro and maintains this activity in vivo in patients with skin papillomas. In addition, HAMLET has striking effects on human glioblastomas in a rat xenograft model. After convection-enhanced delivery, HAMLET diffuses throughout the brain, selectively killing tumor cells and controlling tumor progression without apparent tissue toxicity. HAMLET thus shows great promise as a new therapeutic with the advantage of selectivity for tumor cells and lack of toxicity.

Alternate metabolism during the dauer stage of the nematode Caenorhabditis elegans.

PubMed

Burnell, Ann M; Houthoofd, Koen; O'Hanlon, Karen; Vanfleteren, Jacques R

2005-11-01

When environmental conditions are unsuitable to support nematode reproduction, Caenorhabditis elegans arrests development before the onset of sexual maturity and specialised 'dauer' larvae, adapted for dispersal, and extended diapause are formed. Dauer larvae do not feed and their metabolism is dependent on internal food reserves. Adult worms which express defects in the insulin/insulin-like growth factor receptor DAF-2 also display enhanced longevity. Whole genome mRNA expression profiling has demonstrated that C. elegans dauer larvae and daf-2 adults have similar transcription profiles for a cohort of longevity genes. Important components of this enhanced longevity system are the alpha-crystallin family of small heat shock proteins, anti-ROS defence systems, increased activity of cellular detoxification processes and possibly also increased chromatin stability and decreased protein turnover. Anaerobic fermentation pathways are upregulated in dauer larvae, while long-lived daf-2 adults appear to have normal oxidative metabolism. Anabolic pathways are down regulated in dauer larvae (and possibly in daf-2 adults as well), and energy consumption appears to be diverted to enhanced cellular maintenance and detoxification processes in both systems.

The epithelial-mesenchymal interactions: insights into physiological and pathological aspects of oral tissues.

PubMed

Santosh, Arvind Babu Rajendra; Jones, Thaon Jon

2014-03-17

In the human biological system, the individual cells divide and form tissues and organs. These tissues are hetero-cellular. Basically any tissue consists of an epithelium and the connective tissue. The latter contains mainly mesenchymally-derived tissues with a diversified cell population. The cell continues to grow and differentiate in a pre-programmed manner using a messenger system. The epithelium and the mesenchymal portion of each tissue have two different origins and perform specific functions, but there is a well-defined interaction mechanism, which mediates between them. Epithelial mesenchymal interactions (EMIs) are part of this mechanism, which can be regarded as a biological conversation between epithelial and mesenchymal cell populations involved in the cellular differentiation of one or both cell populations. EMIs represent a process that is essential for cell growth, cell differentiation and cell multiplication. EMIs are associated with normal physiological processes in the oral cavity, such as odontogenesis, dentino-enamel junction formation, salivary gland development, palatogenesis, and also pathological processes, such as oral cancer. This paper focuses the role EMIs in odontogenesis, salivary gland development, palatogenesis and oral cancer.

Copy number determination of genetically-modified hematopoietic stem cells.

PubMed

Schuesler, Todd; Reeves, Lilith; Kalle, Christof von; Grassman, Elke

2009-01-01

Human gene transfer with gammaretroviral, murine leukemia virus (MLV) based vectors has been shown to effectively insert and express transgene sequences at a level of therapeutic benefit. However, there are numerous reports of disruption of the normal cellular processes caused by the viral insertion, even of replication deficient gammaretroviral vectors. Current gammaretroviral and lentiviral vectors do not control the site of insertion into the genome, hence, the possibility of disruption of the target cell genome. Risk related to viral insertions is linked to the number of insertions of the transgene into the cellular DNA, as has been demonstrated for replication competent and replication deficient retroviruses in experiments. At high number of insertions per cell, cell transformation due to vector induced activation of proto-oncogenes is more likely to occur, in particular since more than one transforming event is needed for oncogenesis. Thus, determination of the vector copy number in bulk transduced populations, individual colony forming units, and tissue from the recipient of the transduced cells is an increasingly important safety assay and has become a standard, though not straightforward assay, since the inception of quantitative PCR.

The Impact of Sleep Deprivation on the Brain

PubMed

Trošt Bobić, Tatjana; Šečić, Ana; Zavoreo, Iris; Matijević, Valentina; Filipović, Branimir; Kolak, Željka; Bašić Kes, Vanja; Ciliga, Dubravka; Sajković, Dubravka

2016-09-01

Each sleep phase is characterized by specific chemical, cellular and anatomic events of vital importance for normal neural functioning. Different forms of sleep deprivation may lead to a decline of cognitive functions in individuals. Studies in this field make a distinction between total sleep deprivation, chronic sleep restriction, and the situation of sleep disruption. Investigations covering the acute effects of sleep deprivation on the brain show that the discovered behavioral deficits in most cases regenerate after two nights of complete sleep. However, some studies done on mice emphasize the possible chronic effects of long-term sleep deprivation or chronic restriction on the occurrence of neurodegenerative diseases such as Alzheimer’s disease and dementia. In order to better understand the acute and chronic effects of sleep loss, the mechanisms of neural adaptation in the situations of insufficient sleep need to be further investigated. Future integrative research on the impact of sleep deprivation on neural functioning measured through the macro level of cognitive functions and the micro molecular and cell level could contribute to more accurate conclusions about the basic cellular mechanisms responsible for the detected behavioral deficits occurring due to sleep deprivation.

Airway epithelial repair in health and disease: Orchestrator or simply a player?

PubMed

Iosifidis, Thomas; Garratt, Luke W; Coombe, Deirdre R; Knight, Darryl A; Stick, Stephen M; Kicic, Anthony

2016-04-01

Epithelial cells represent the most important surface of contact in the body and form the first line of defence of the body to external environment. Consequently, epithelia have numerous roles in order to maintain a homeostatic defence barrier. Although the epithelium has been extensively studied over several decades, it remains the focus of new research, indicating a lack of understanding that continues to exist around these cells in specific disease settings. Importantly, evidence is emerging that airway epithelial cells in particular have varied complex functions rather than simple passive roles. One area of current interest is its role following injury. In particular, the epithelial-specific cellular mechanisms regulating their migration during wound repair remain poorly understood and remain an area that requires much needed investigation. A better understanding of the physiological, cellular and molecular wound repair mechanisms could assist in elucidating pathological processes that contribute to airway epithelial pathology. This review attempts to highlight migration-specific and cell-extracellular matrix (ECM) aspects of repair used by epithelial cells under normal and disease settings, in the context of human airways. © 2016 Asian Pacific Society of Respirology.

In vivo NAD assay reveals the intracellular NAD contents and redox state in healthy human brain and their age dependences

PubMed Central

Zhu, Xiao-Hong; Lu, Ming; Lee, Byeong-Yeul; Ugurbil, Kamil; Chen, Wei

2015-01-01

NAD is an essential metabolite that exists in NAD+ or NADH form in all living cells. Despite its critical roles in regulating mitochondrial energy production through the NAD+/NADH redox state and modulating cellular signaling processes through the activity of the NAD+-dependent enzymes, the method for quantifying intracellular NAD contents and redox state is limited to a few in vitro or ex vivo assays, which are not suitable for studying a living brain or organ. Here, we present a magnetic resonance (MR) -based in vivo NAD assay that uses the high-field MR scanner and is capable of noninvasively assessing NAD+ and NADH contents and the NAD+/NADH redox state in intact human brain. The results of this study provide the first insight, to our knowledge, into the cellular NAD concentrations and redox state in the brains of healthy volunteers. Furthermore, an age-dependent increase of intracellular NADH and age-dependent reductions in NAD+, total NAD contents, and NAD+/NADH redox potential of the healthy human brain were revealed in this study. The overall findings not only provide direct evidence of declined mitochondrial functions and altered NAD homeostasis that accompany the normal aging process but also, elucidate the merits and potentials of this new NAD assay for noninvasively studying the intracellular NAD metabolism and redox state in normal and diseased human brain or other organs in situ. PMID:25730862

Review of the etiologies of viral meningitis and encephalitis in a dengue endemic region.

PubMed

Soares, Cristiane N; Cabral-Castro, Mauro J; Peralta, José M; de Freitas, Marcos R G; Zalis, Mariano; Puccioni-Sohler, Marzia

2011-04-15

To evaluate the etiology of viral meningitis and encephalitis in adults and adolescents living in areas affected by dengue. Over two years, adults and adolescents with diagnoses of viral encephalitis or meningitis were selected for study in Brazil. PCRs for dengue, enterovirus, HSV1 and 2 and cytomegalovirus were performed in CSF samples. Serum and CSF samples were tested for the presence of anti-dengue IgM antibodies. The etiologies of encephalitis and meningitis were determined in 70% of cases (30/47). Dengue was the leading cause of encephalitis (47%) with normal CSF cellularity in 75% of these patients. HSV1 was found in 17.6% of the cases, two of which had mild encephalitis. Enterovirus was the most common cause of meningitis (50%), followed by HSV1 (15%), cytomegalovirus and dengue (10%, each). We identified the viral agents causing encephalitis and meningitis in a higher proportion of cases than has been reported in other studies. Dengue was the most frequent cause of encephalitis, which surpassed HSV. In endemic areas, dengue should be investigated as an important cause of encephalitis. Normal CSF cellularity should not exclude dengue encephalitis. Enterovirus is known to be the leading cause of meningitis in children, but here we found it was also the main cause of the disease in adults. HSV1 should be investigated in patients with mild forms of encephalitis and meningitis. Copyright © 2011 Elsevier B.V. All rights reserved.

The chromatin-binding protein Smyd1 restricts adult mammalian heart growth

PubMed Central

Kimball, Todd; Rasmussen, Tara L.; Rosa-Garrido, Manuel; Chen, Haodong; Tran, Tam; Miller, Mickey R.; Gray, Ricardo; Jiang, Shanxi; Ren, Shuxun; Wang, Yibin; Tucker, Haley O.; Vondriska, Thomas M.

2016-01-01

All terminally differentiated organs face two challenges, maintaining their cellular identity and restricting organ size. The molecular mechanisms responsible for these decisions are of critical importance to organismal development, and perturbations in their normal balance can lead to disease. A hallmark of heart failure, a condition affecting millions of people worldwide, is hypertrophic growth of cardiomyocytes. The various forms of heart failure in human and animal models share conserved transcriptome remodeling events that lead to expression of genes normally silenced in the healthy adult heart. However, the chromatin remodeling events that maintain cell and organ size are incompletely understood; insights into these mechanisms could provide new targets for heart failure therapy. Using a quantitative proteomics approach to identify muscle-specific chromatin regulators in a mouse model of hypertrophy and heart failure, we identified upregulation of the histone methyltransferase Smyd1 during disease. Inducible loss-of-function studies in vivo demonstrate that Smyd1 is responsible for restricting growth in the adult heart, with its absence leading to cellular hypertrophy, organ remodeling, and fulminate heart failure. Molecular studies reveal Smyd1 to be a muscle-specific regulator of gene expression and indicate that Smyd1 modulates expression of gene isoforms whose expression is associated with cardiac pathology. Importantly, activation of Smyd1 can prevent pathological cell growth. These findings have basic implications for our understanding of cardiac pathologies and open new avenues to the treatment of cardiac hypertrophy and failure by modulating Smyd1. PMID:27663768

The chromatin-binding protein Smyd1 restricts adult mammalian heart growth.

PubMed

Franklin, Sarah; Kimball, Todd; Rasmussen, Tara L; Rosa-Garrido, Manuel; Chen, Haodong; Tran, Tam; Miller, Mickey R; Gray, Ricardo; Jiang, Shanxi; Ren, Shuxun; Wang, Yibin; Tucker, Haley O; Vondriska, Thomas M

2016-11-01

All terminally differentiated organs face two challenges, maintaining their cellular identity and restricting organ size. The molecular mechanisms responsible for these decisions are of critical importance to organismal development, and perturbations in their normal balance can lead to disease. A hallmark of heart failure, a condition affecting millions of people worldwide, is hypertrophic growth of cardiomyocytes. The various forms of heart failure in human and animal models share conserved transcriptome remodeling events that lead to expression of genes normally silenced in the healthy adult heart. However, the chromatin remodeling events that maintain cell and organ size are incompletely understood; insights into these mechanisms could provide new targets for heart failure therapy. Using a quantitative proteomics approach to identify muscle-specific chromatin regulators in a mouse model of hypertrophy and heart failure, we identified upregulation of the histone methyltransferase Smyd1 during disease. Inducible loss-of-function studies in vivo demonstrate that Smyd1 is responsible for restricting growth in the adult heart, with its absence leading to cellular hypertrophy, organ remodeling, and fulminate heart failure. Molecular studies reveal Smyd1 to be a muscle-specific regulator of gene expression and indicate that Smyd1 modulates expression of gene isoforms whose expression is associated with cardiac pathology. Importantly, activation of Smyd1 can prevent pathological cell growth. These findings have basic implications for our understanding of cardiac pathologies and open new avenues to the treatment of cardiac hypertrophy and failure by modulating Smyd1. Copyright © 2016 the American Physiological Society.

Feeding behavior of Aplysia: a model system for comparing cellular mechanisms of classical and operant conditioning.

PubMed

Baxter, Douglas A; Byrne, John H

2006-01-01

Feeding behavior of Aplysia provides an excellent model system for analyzing and comparing mechanisms underlying appetitive classical conditioning and reward operant conditioning. Behavioral protocols have been developed for both forms of associative learning, both of which increase the occurrence of biting following training. Because the neural circuitry that mediates the behavior is well characterized and amenable to detailed cellular analyses, substantial progress has been made toward a comparative analysis of the cellular mechanisms underlying these two forms of associative learning. Both forms of associative learning use the same reinforcement pathway (the esophageal nerve, En) and the same reinforcement transmitter (dopamine, DA). In addition, at least one cellular locus of plasticity (cell B51) is modified by both forms of associative learning. However, the two forms of associative learning have opposite effects on B51. Classical conditioning decreases the excitability of B51, whereas operant conditioning increases the excitability of B51. Thus, the approach of using two forms of associative learning to modify a single behavior, which is mediated by an analytically tractable neural circuit, is revealing similarities and differences in the mechanisms that underlie classical and operant conditioning.

Preface: cardiac control pathways: signaling and transport phenomena.

PubMed

Sideman, Samuel

2008-03-01

Signaling is part of a complex system of communication that governs basic cellular functions and coordinates cellular activity. Transfer of ions and signaling molecules and their interactions with appropriate receptors, transmembrane transport, and the consequent intracellular interactions and functional cellular response represent a complex system of interwoven phenomena of transport, signaling, conformational changes, chemical activation, and/or genetic expression. The well-being of the cell thus depends on a harmonic orchestration of all these events and the existence of control mechanisms that assure the normal behavior of the various parameters involved and their orderly expression. The ability of cells to sustain life by perceiving and responding correctly to their microenvironment is the basis for development, tissue repair, and immunity, as well as normal tissue homeostasis. Natural deviations, or human-induced interference in the signaling pathways and/or inter- and intracellular transport and information transfer, are responsible for the generation, modulation, and control of diseases. The present overview aims to highlight some major topics of the highly complex cellular information transfer processes and their control mechanisms. Our goal is to contribute to the understanding of the normal and pathophysiological phenomena associated with cardiac functions so that more efficient therapeutic modalities can be developed. Our objective in this volume is to identify and enhance the study of some basic passive and active physical and chemical transport phenomena, physiological signaling pathways, and their biological consequences.

Fluorescence-based detection and quantification of features of cellular senescence.

PubMed

Cho, Sohee; Hwang, Eun Seong

2011-01-01

Cellular senescence is a spontaneous organismal defense mechanism against tumor progression which is raised upon the activation of oncoproteins or other cellular environmental stresses that must be circumvented for tumorigenesis to occur. It involves growth-arrest state of normal cells after a number of active divisions. There are multiple experimental routes that can drive cells into a state of senescence. Normal somatic cells and cancer cells enter a state of senescence upon overexpression of oncogenic Ras or Raf protein or by imposing certain kinds of stress such as cellular tumor suppressor function. Both flow cytometry and confocal imaging analysis techniques are very useful in quantitative analysis of cellular senescence phenomenon. They allow quantitative estimates of multiple different phenotypes expressed in multiple cell populations simultaneously. Here we review the various types of fluorescence methodologies including confocal imaging and flow cytometry that are frequently utilized to study a variety of senescence. First, we discuss key cell biological changes occurring during senescence and review the current understanding on the mechanisms of these changes with the goal of improving existing protocols and further developing new ones. Next, we list specific senescence phenotypes associated with each cellular trait along with the principles of their assay methods and the significance of the assay outcomes. We conclude by selecting appropriate references that demonstrate a typical example of each method. Copyright © 2011 Elsevier Inc. All rights reserved.

Comparative Testis Tissue Proteomics Using 2-Dye Versus 3-Dye DIGE Analysis.

PubMed

Holland, Ashling

2018-01-01

Comparative tissue proteomics aims to analyze alterations of the proteome in response to a stimulus. Two-dimensional difference gel electrophoresis (2D-DIGE) is a modified and advanced form of 2D gel electrophoresis. DIGE is a powerful biochemical method that compares two or three protein samples on the same analytical gel, and can be used to establish differentially expressed protein levels between healthy normal and diseased pathological tissue sample groups. Minimal DIGE labeling can be used via a 2-dye system with Cy3 and Cy5 or a 3-dye system with Cy2, Cy3, and Cy5 to fluorescently label samples with CyDye flours pre-electrophoresis. DIGE circumvents gel-to-gel variability by multiplexing samples to a single gel and through the use of a pooled internal standard for normalization. This form of quantitative high-resolution proteomics facilitates the comparative analysis and evaluation of tissue protein compositions. Comparing tissue groups under different conditions is crucially important for advancing the biomedical field by characterization of cellular processes, understanding pathophysiological development and tissue biomarker discovery. This chapter discusses 2D-DIGE as a comparative tissue proteomic technique and describes in detail the experimental steps required for comparative proteomic analysis employing both options of 2-dye and 3-dye DIGE minimal labeling.

Cellular senescence and organismal aging.

PubMed

Jeyapalan, Jessie C; Sedivy, John M

2008-01-01

Cellular senescence, first observed and defined using in vitro cell culture studies, is an irreversible cell cycle arrest which can be triggered by a variety of factors. Emerging evidence suggests that cellular senescence acts as an in vivo tumor suppression mechanism by limiting aberrant proliferation. It has also been postulated that cellular senescence can occur independently of cancer and contribute to the physiological processes of normal organismal aging. Recent data have demonstrated the in vivo accumulation of senescent cells with advancing age. Some characteristics of senescent cells, such as the ability to modify their extracellular environment, could play a role in aging and age-related pathology. In this review, we examine current evidence that links cellular senescence and organismal aging.

Cellular senescence and organismal aging

PubMed Central

Jeyapalan, Jessie C.; Sedivy, John M.

2012-01-01

Cellular senescence, first observed and defined using in vitro cell culture studies, is an irreversible cell cycle arrest which can be triggered by a variety of factors. Emerging evidence suggests that cellular senescence acts as an in vivo tumor suppression mechanism by limiting aberrant proliferation. It has also been postulated that cellular senescence can occur independently of cancer and contribute to the physiological processes of normal organismal aging. Recent data have demonstrated the in vivo accumulation of senescent cells with advancing age. Some characteristics of senescent cells, such as the ability to modify their extracellular environment, could play a role in aging and age related pathology. In this review, we examine current evidence that links cellular senescence and organismal aging. PMID:18502472

Cytotoxicity evaluation of a copaiba oil-based root canal sealer compared to three commonly used sealers in endodontics

PubMed Central

Garrido, Angela Delfina Bittencourt; de Cara, Sueli Patricia Harumi Miyagi; Marques, Marcia Martins; Sponchiado, Emílio Carlos; Garcia, Lucas da Fonseca Roberti; de Sousa-Neto, Manoel Damião

2015-01-01

Background: The constant development of new root canal sealers has allowed the solution of a large number of clinical cases in endodontics, however, cytotoxicity of such sealers must be tested before their validation as filling materials. The aim of this study was to evaluate the cytotoxic effect of a new Copaiba oil-based root canal sealer (Biosealer [BS]) on osteoblast-like Osteo-1 cells. Materials and Methods: The experimental groups were formed according to the culture medium conditioned with the tested sealers, as follows: Control group (CG) (culture medium without conditioning); Sealer 26 (S26) - culture medium + S26; Endofill (EF) - culture medium + EF; AH Plus (AHP) - culture medium + AHP; and BS - culture medium + BS (Copaiba oil-based sealer). The conditioned culture medium was placed in contact with 2 × 104 cells cultivated on 60 mm diameter Petri dishes for 24 h. Then, hemocytometer count was performed to evaluate cellular viability, using Trypan Blue assay. The normal distribution of data was tested by the Kolmogorov-Smirnov test and the values obtained for cellular viability were statistically analyzed (1-way ANOVA, Tukey's test - P < 0.05), with a significance level of 5%. Results: S26, EF and AHP presented decreased cellular viability considerably, with statistical significance compared with CG (P < 0.05). BS maintained cellular viability similar to CG (P > 0.05). Conclusion: The Copaiba oil-based root canal sealer presented promising results in terms of cytotoxicity which indicated its usefulness as a root canal sealer. PMID:25878676

Comparative expression analysis of Septin 14 in testes of infertile men with normal spermatogenesis and spermatogenic failure

PubMed Central

Shafipour, Maryam; Sabbaghian, Marjan; Shahhoseini, Maryam; Sadighi Gilani, Mohammad Ali

2014-01-01

Background: Septins are an evolutionary conserved group of GTP-binding and filament-forming proteins that have diverse cellular roles. An increasing body of data implicates the septin family in the pathogenesis of diverse states including cancers, neurodegeneration, and male infertility. Objective: The objective of the study was to evaluate the expression pattern of Septin14 in testis tissue of men with and without spermatogenic failure. Materials and Methods: The samples retrieved accessible random between infertile men who underwent diagnostic testicular biopsy in Royan institute. 10 infertile men with obstructive azoospermia and normal spermatogenesis and 20 infertile men with non-obstructive azoospermia were recruited for real-time reverse transcription (RT)-PCR analysis of the testicular tissue. Total RNA was extracted with trizol reagent. Results: Comparison of the mRNA level of septin14 revealed that in tissues with partial (n=10) or complete spermatogenesis (n=10), the expression of septin 14 was significantly higher than sertoli cell only tissues. Conclusion: The testicular tissues of men with hypospermatogenesis, maturation arrest and sertoli cell only had lower levels of septin 14 transcripts than normal men. These data indicates that Septin 14 expression level is critical for human spermatogenesis. PMID:24799881

Insulin resistance in patients with recurrent pregnancy loss is associated with lymphocyte population aberration.

PubMed

Yan, Yan; Bao, Shihua; Sheng, Shile; Wang, Liuliu; Tu, Weiyan

2017-12-01

This study was designed to investigate the relationship of insulin resistance (IR) and cellular immune abnormalities associated with women with recurrent pregnancy loss (RPL). Women with RPL were divided into two groups according to their homeostasis model assessment for IR (HOMA-IR) scores. The IR group received metformin approximately 3 months before pregnancy. The percentage of lymphocyte subsets and other blood biochemical indices were tested. The HOMA-IR and fasting serum insulin levels were related to the percentage of lymphocyte subsets. The women with RPL had higher CD3 + and CD3 + CD4 + cell levels while CD56 + CD16 + cell levels were lower. A higher likelihood of cellular immune abnormalities was observed. Women with normal lymphocyte subsets had normal pregnancy outcomes. Metformin significantly downregulated CD3 + and CD3 + CD4 + cells and improved pregnancy outcomes. IR was associated with cellular immune abnormalities in RPL. The data suggests that metformin affected the immune/inflammatory response, which may regulate the cellular immune balance and improve pregnancy outcomes. Abbreviations RPL: recurrent pregnancy loss; IR insulin resistance; HOMA-IR: homeostasis model assessment for IR.

Functional response of osteoblasts in functionally gradient titanium alloy mesh arrays processed by 3D additive manufacturing.

PubMed

Nune, K C; Kumar, A; Misra, R D K; Li, S J; Hao, Y L; Yang, R

2017-02-01

We elucidate here the osteoblasts functions and cellular activity in 3D printed interconnected porous architecture of functionally gradient Ti-6Al-4V alloy mesh structures in terms of cell proliferation and growth, distribution of cell nuclei, synthesis of proteins (actin, vinculin, and fibronectin), and calcium deposition. Cell culture studies with pre-osteoblasts indicated that the interconnected porous architecture of functionally gradient mesh arrays was conducive to osteoblast functions. However, there were statistically significant differences in the cellular response depending on the pore size in the functionally gradient structure. The interconnected porous architecture contributed to the distribution of cells from the large pore size (G1) to the small pore size (G3), with consequent synthesis of extracellular matrix and calcium precipitation. The gradient mesh structure significantly impacted cell adhesion and influenced the proliferation stage, such that there was high distribution of cells on struts of the gradient mesh structure. Actin and vinculin showed a significant difference in normalized expression level of protein per cell, which was absent in the case of fibronectin. Osteoblasts present on mesh struts formed a confluent sheet, bridging the pores through numerous cytoplasmic extensions. The gradient mesh structure fabricated by electron beam melting was explored to obtain fundamental insights on cellular activity with respect to osteoblast functions. Copyright © 2016 Elsevier B.V. All rights reserved.

Cell-autonomous correction of ring chromosomes in human induced pluripotent stem cells

NASA Astrophysics Data System (ADS)

Bershteyn, Marina; Hayashi, Yohei; Desachy, Guillaume; Hsiao, Edward C.; Sami, Salma; Tsang, Kathryn M.; Weiss, Lauren A.; Kriegstein, Arnold R.; Yamanaka, Shinya; Wynshaw-Boris, Anthony

2014-03-01

Ring chromosomes are structural aberrations commonly associated with birth defects, mental disabilities and growth retardation. Rings form after fusion of the long and short arms of a chromosome, and are sometimes associated with large terminal deletions. Owing to the severity of these large aberrations that can affect multiple contiguous genes, no possible therapeutic strategies for ring chromosome disorders have been proposed. During cell division, ring chromosomes can exhibit unstable behaviour leading to continuous production of aneuploid progeny with low viability and high cellular death rate. The overall consequences of this chromosomal instability have been largely unexplored in experimental model systems. Here we generated human induced pluripotent stem cells (iPSCs) from patient fibroblasts containing ring chromosomes with large deletions and found that reprogrammed cells lost the abnormal chromosome and duplicated the wild-type homologue through the compensatory uniparental disomy (UPD) mechanism. The karyotypically normal iPSCs with isodisomy for the corrected chromosome outgrew co-existing aneuploid populations, enabling rapid and efficient isolation of patient-derived iPSCs devoid of the original chromosomal aberration. Our results suggest a fundamentally different function for cellular reprogramming as a means of `chromosome therapy' to reverse combined loss-of-function across many genes in cells with large-scale aberrations involving ring structures. In addition, our work provides an experimentally tractable human cellular system for studying mechanisms of chromosomal number control, which is of critical relevance to human development and disease.

The development and plasticity of alveolar type 1 cells

PubMed Central

Yang, Jun; Hernandez, Belinda J.; Martinez Alanis, Denise; Narvaez del Pilar, Odemaris; Vila-Ellis, Lisandra; Akiyama, Haruhiko; Evans, Scott E.; Ostrin, Edwin J.; Chen, Jichao

2016-01-01

Alveolar type 1 (AT1) cells cover >95% of the gas exchange surface and are extremely thin to facilitate passive gas diffusion. The development of these highly specialized cells and its coordination with the formation of the honeycomb-like alveolar structure are poorly understood. Using new marker-based stereology and single-cell imaging methods, we show that AT1 cells in the mouse lung form expansive thin cellular extensions via a non-proliferative two-step process while retaining cellular plasticity. In the flattening step, AT1 cells undergo molecular specification and remodel cell junctions while remaining connected to their epithelial neighbors. In the folding step, AT1 cells increase in size by more than 10-fold and undergo cellular morphogenesis that matches capillary and secondary septa formation, resulting in a single AT1 cell spanning multiple alveoli. Furthermore, AT1 cells are an unexpected source of VEGFA and their normal development is required for alveolar angiogenesis. Notably, a majority of AT1 cells proliferate upon ectopic SOX2 expression and undergo stage-dependent cell fate reprogramming. These results provide evidence that AT1 cells have both structural and signaling roles in alveolar maturation and can exit their terminally differentiated non-proliferative state. Our findings suggest that AT1 cells might be a new target in the pathogenesis and treatment of lung diseases associated with premature birth. PMID:26586225

Extracellular calcium controls the expression of two different forms of ripple-like hippocampal oscillations.

PubMed

Aivar, Paloma; Valero, Manuel; Bellistri, Elisa; Menendez de la Prida, Liset

2014-02-19

Hippocampal high-frequency oscillations (HFOs) are prominent in physiological and pathological conditions. During physiological ripples (100-200 Hz), few pyramidal cells fire together coordinated by rhythmic inhibitory potentials. In the epileptic hippocampus, fast ripples (>200 Hz) reflect population spikes (PSs) from clusters of bursting cells, but HFOs in the ripple and the fast ripple range are vastly intermixed. What is the meaning of this frequency range? What determines the expression of different HFOs? Here, we used different concentrations of Ca(2+) in a physiological range (1-3 mM) to record local field potentials and single cells in hippocampal slices from normal rats. Surprisingly, we found that this sole manipulation results in the emergence of two forms of HFOs reminiscent of ripples and fast ripples recorded in vivo from normal and epileptic rats, respectively. We scrutinized the cellular correlates and mechanisms underlying the emergence of these two forms of HFOs by combining multisite, single-cell and paired-cell recordings in slices prepared from a rat reporter line that facilitates identification of GABAergic cells. We found a major effect of extracellular Ca(2+) in modulating intrinsic excitability and disynaptic inhibition, two critical factors shaping network dynamics. Moreover, locally modulating the extracellular Ca(2+) concentration in an in vivo environment had a similar effect on disynaptic inhibition, pyramidal cell excitability, and ripple dynamics. Therefore, the HFO frequency band reflects a range of firing dynamics of hippocampal networks.

A Novel Function for the nm23-Hl Gene: Overexpression in Human Breast Carcinoma Cells Leads to the Formation of Basement Membrane and Growth Arrest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howlett, Anthony R; Petersen, Ole W; Steeg, Patricia S

1994-01-01

We have developed a culture system using reconstituted basement membrane components in which normal human mammary epithelial cells exhibit several aspects of the development and differentiation process, including formation of acinar-like structures, production and basal deposition of basement membrane components, and production and apical secretion of sialomucins. Cell lines and cultures from human breast carcinomas failed to recapitulate this process. The data indicate the importance of cellular interactions with the basement membrane in the regulation of normal breast differentiation and, potentially, its loss in neoplasia. Our purpose was to use this assay to investigate the role of the putative metastasismore » suppressor gene nm23-H1 in mammary development and differentiation. The metastatic human breast carcinoma cell line MDA-MB-435, clones transfected with a control pCMVBamneo vector, and clones transfected with pCMVBamneo vector containing nm23-H1 complementary DNA (the latter of which exhibited a substantial reduction in spontaneous metastatic potential in vivo) were cultured within a reconstituted basement membrane. Clones were examined for formation of acinus-like spheres, deposition of basement membrane components, production of sialomucin, polarization, and growth arrest. In contrast to the parental cell line and control transfectants, MDA-MB-435 breast carcinoma cells overexpressing Nm23-H1 protein regained several aspects of the normal phenotype within reconstituted basement membrane. Nm23-H1 protein-positive cells formed organized acinus-like spheres, deposited the basement membrane components type IV collagen and, to some extent, laminin to the outside of the spheres, expressed sialomucin, and growth arrested. Growth arrest of Nm23-H1 protein-positive cells was preceded by and correlated with formation of a basement membrane, suggesting a causal relationship. The data indicate a previously unidentified cause-and-effect relationship between nm23-H1 gene expression and morphological-biosynthetic-growth aspects of breast differentiation in this model system. While the basement membrane microenvironment is capable of directing the differentiation of normal human breast cells, neoplastic transformation abrogates this relationship, suggesting that intrinsic cellular events are also critical to this process. The data identify nm23-H1 gene expression as one of these events, suggesting an important role in the modulation of cellular responsiveness to the microenvironment. The data also identify previously unknown growth inhibitory effects of nm23-H1 gene overexpression.« less

The [RNQ+] prion

PubMed Central

Stein, Kevin C

2011-01-01

The formation of fibrillar amyloid is most often associated with protein conformational disorders such as prion diseases, Alzheimer disease and Huntington disease. Interestingly, however, an increasing number of studies suggest that amyloid structures can sometimes play a functional role in normal biology. Several proteins form self-propagating amyloids called prions in the budding yeast Saccharomyces cerevisiae. These unique elements operate by creating a reversible, epigenetic change in phenotype. While the function of the non-prion conformation of the Rnq1 protein is unclear, the prion form, [RNQ+], acts to facilitate the de novo formation of other prions to influence cellular phenotypes. The [RNQ+] prion itself does not adversely affect the growth of yeast, but the overexpression of Rnq1p can form toxic aggregated structures that are not necessarily prions. The [RNQ+] prion is also involved in dictating the aggregation and toxicity of polyglutamine proteins ectopically expressed in yeast. Thus, the [RNQ+] prion provides a tractable model that has the potential to reveal significant insight into the factors that dictate how amyloid structures are initiated and propagated in both physiological and pathological contexts. PMID:22052347

Discoidin domain receptor 2 (DDR2) regulates proliferation of endochondral cells in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawai, Ikuma; Hisaki, Tomoka; Sugiura, Koji

2012-10-26

Highlights: Black-Right-Pointing-Pointer Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase. Black-Right-Pointing-Pointer DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. Black-Right-Pointing-Pointer We produced in vitro and in vivo model to better understand the role of DDR2. Black-Right-Pointing-Pointer DDR2 might play an inhibitory role in the proliferation of chondrocyte. -- Abstract: Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase that is activated by fibrillar collagens. DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. The decrement of endogenous DDR2 represses osteoblastic marker gene expression and osteogenic differentiation in murine preosteoblastic cells, but themore » functions of DDR2 in chondrogenic cellular proliferation remain unclear. To better understand the role of DDR2 signaling in cellular proliferation in endochondral ossification, we inhibited Ddr2 expression via the inhibitory effect of miRNA on Ddr2 mRNA (miDdr2) and analyzed the cellular proliferation and differentiation in the prechondrocyte ATDC5 cell lines. To investigate DDR2's molecular role in endochondral cellular proliferation in vivo, we also produced transgenic mice in which the expression of truncated, kinase dead (KD) DDR2 protein is induced, and evaluated the DDR2 function in cellular proliferation in chondrocytes. Although the miDdr2-transfected ATDC5 cell lines retained normal differentiation ability, DDR2 reduction finally promoted cellular proliferation in proportion to the decreasing ratio of Ddr2 expression, and it also promoted earlier differentiation to cartilage cells by insulin induction. The layer of hypertrophic chondrocytes in KD Ddr2 transgenic mice was not significantly thicker than that of normal littermates, but the layer of proliferative chondrocytes in KD-Ddr2 transgenic mice was significantly thicker than that of normal littermates. Taken together, our data demonstrated that DDR2 might play a local and essential role in the proliferation of chondrocytes.« less

Molecular and cellular neurocardiology: development, and cellular and molecular adaptations to heart disease

PubMed Central

Anderson, Mark E.; Birren, Susan J.; Fukuda, Keiichi; Herring, Neil; Hoover, Donald B.; Kanazawa, Hideaki; Paterson, David J.; Ripplinger, Crystal M.

2016-01-01

Abstract The nervous system and cardiovascular system develop in concert and are functionally interconnected in both health and disease. This white paper focuses on the cellular and molecular mechanisms that underlie neural–cardiac interactions during development, during normal physiological function in the mature system, and during pathological remodelling in cardiovascular disease. The content on each subject was contributed by experts, and we hope that this will provide a useful resource for newcomers to neurocardiology as well as aficionados. PMID:27060296

Prion-based memory of heat stress in yeast

PubMed Central

Chernova, Tatiana A.; Wilkinson, Keith D.

2017-01-01

ABSTRACT Amyloids and amyloid-based prions are self-perpetuating protein aggregates which can spread by converting a normal protein of the same sequence into a prion form. They are associated with diseases in humans and mammals, and control heritable traits in yeast and other fungi. Some amyloids are implicated in biologically beneficial processes. As prion formation generates reproducible memory of a conformational change, prions can be considered as molecular memory devices.  We have demonstrated that in yeast, stress-inducible cytoskeleton-associated protein Lsb2 forms a metastable prion in response to high temperature. This prion promotes conversion of other proteins into prions and can persist in a fraction of cells for a significant number of cell generations after stress, thus maintaining the memory of stress in a population of surviving cells. Acquisition of an amino acid substitution required for Lsb2 to form a prion coincides with acquisition of increased thermotolerance in the evolution of Saccharomyces yeast. Thus the ability to form an Lsb2 prion in response to stress coincides with yeast adaptation to growth at higher temperatures. These findings intimately connect prion formation to the cellular response to environmental stresses. PMID:28521568

Prion-based memory of heat stress in yeast.

PubMed

Chernova, Tatiana A; Chernoff, Yury O; Wilkinson, Keith D

2017-05-04

Amyloids and amyloid-based prions are self-perpetuating protein aggregates which can spread by converting a normal protein of the same sequence into a prion form. They are associated with diseases in humans and mammals, and control heritable traits in yeast and other fungi. Some amyloids are implicated in biologically beneficial processes. As prion formation generates reproducible memory of a conformational change, prions can be considered as molecular memory devices.  We have demonstrated that in yeast, stress-inducible cytoskeleton-associated protein Lsb2 forms a metastable prion in response to high temperature. This prion promotes conversion of other proteins into prions and can persist in a fraction of cells for a significant number of cell generations after stress, thus maintaining the memory of stress in a population of surviving cells. Acquisition of an amino acid substitution required for Lsb2 to form a prion coincides with acquisition of increased thermotolerance in the evolution of Saccharomyces yeast. Thus the ability to form an Lsb2 prion in response to stress coincides with yeast adaptation to growth at higher temperatures. These findings intimately connect prion formation to the cellular response to environmental stresses.

A role for autophagic protein beclin 1 early in lymphocyte development.

PubMed

Arsov, Ivica; Adebayo, Adeola; Kucerova-Levisohn, Martina; Haye, Joanna; MacNeil, Margaret; Papavasiliou, F Nina; Yue, Zhenyu; Ortiz, Benjamin D

2011-02-15

Autophagy is a highly regulated and evolutionarily conserved process of cellular self-digestion. Recent evidence suggests that this process plays an important role in regulating T cell homeostasis. In this study, we used Rag1(-/-) (recombination activating gene 1(-/-)) blastocyst complementation and in vitro embryonic stem cell differentiation to address the role of Beclin 1, one of the key autophagic proteins, in lymphocyte development. Beclin 1-deficient Rag1(-/-) chimeras displayed a dramatic reduction in thymic cellularity compared with control mice. Using embryonic stem cell differentiation in vitro, we found that the inability to maintain normal thymic cellularity is likely caused by impaired maintenance of thymocyte progenitors. Interestingly, despite drastically reduced thymocyte numbers, the peripheral T cell compartment of Beclin 1-deficient Rag1(-/-) chimeras is largely normal. Peripheral T cells displayed normal in vitro proliferation despite significantly reduced numbers of autophagosomes. In addition, these chimeras had greatly reduced numbers of early B cells in the bone marrow compared with controls. However, the peripheral B cell compartment was not dramatically impacted by Beclin 1 deficiency. Collectively, our results suggest that Beclin 1 is required for maintenance of undifferentiated/early lymphocyte progenitor populations. In contrast, Beclin 1 is largely dispensable for the initial generation and function of the peripheral T and B cell compartments. This indicates that normal lymphocyte development involves Beclin 1-dependent, early-stage and distinct, Beclin 1-independent, late-stage processes.

Profiling cellular bioenergetics, glutathione levels, and caspase activities in stomach biopsies of patients with upper gastrointestinal symptoms

PubMed Central

Alfazari, Ali S; Al-Dabbagh, Bayan; Al-Dhaheri, Wafa; Taha, Mazen S; Chebli, Ahmad A; Fontagnier, Eva M; Koutoubi, Zaher; Kochiyi, Jose; Karam, Sherif M; Souid, Abdul-Kader

2015-01-01

AIM: To measure biochemical parameters in stomach biopsies and test their suitability as diagnostic biomarkers for gastritis and precancerous lesions. METHODS: Biopsies were obtained from the stomachs of two groups of patients (n = 40) undergoing fiber-optic endoscopy due to upper gastrointestinal symptoms. In the first group (n = 17), only the corpus region was examined. Biopsies were processed for microscopic examination and measurement of mitochondrial O2 consumption (cellular respiration), cellular adenosine triphosphate (ATP), glutathione (GSH), and caspase activity. In the second group of patients (n = 23), both corpus and antral regions were studied. Some biopsies were processed for microscopic examination, while the others were used for measurements of cellular respiration and GSH level. RESULTS: Microscopic examinations of gastric corpus biopsies from 17 patients revealed normal mucosae in 8 patients, superficial gastritis in 7 patients, and chronic atrophic gastritis in 1 patient. In patients with normal histology, the rate (mean ± SD) of cellular respiration was 0.17 ± 0.02 μmol/L O2 min-1 mg-1, ATP content was 487 ± 493 pmol/mg, and GSH was 469 ± 98 pmol/mg. Caspase activity was detected in 3 out of 8 specimens. The values of ATP and caspase activity were highly variable. The presence of superficial gastritis had insignificant effects on the measured biomarkers. In the patient with atrophic gastritis, cellular respiration was high and ATP was relatively low, suggesting uncoupling oxidative phosphorylation. In the second cohort of patients, the examined biopsies showed either normal or superficial gastritis. The rate of cellular respiration (O2. μmol/L min-1 mg-1) was slightly higher in the corpus than the antrum (0.18 ± 0.05 vs 0.15 ± 0.04, P = 0.019). The value of GSH was about the same in both tissues (310 ± 135 vs 322 ± 155, P = 0.692). CONCLUSION: The corpus mucosa was metabolically more active than the antrum tissue. The data in this study will help in understanding the pathophysiology of gastric mucosa. PMID:25593494

Insulin-producing cells could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells

PubMed Central

2013-01-01

Objective The aim of this study was to compare the difference between insulin-producing cells (IPCs) and normal human pancreatic beta cells both in physiological function and morphological features in cellular level. Methods The levels of insulin secretion were measured by enzyme-linked immunosorbent assay. The insulin gene expression was determined by real-time quantitative polymerase chain reaction. The morphological features were detected by atomic force microscopy (AFM) and laser confocal scanning microscopy. Results IPCs and normal human pancreatic beta cells were similar to each other under the observation in AFM with the porous structure features in the cytoplasm. Both number of membrane particle size and average roughness of normal human beta cells were higher than those of IPCs. Conclusions Our results firstly revealed that the cellular ultrastructure of IPCs was closer to that of normal human pancreatic beta cells, but they still could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells. PMID:23421382

Serum from calorie-restricted animals delays senescence and extends the lifespan of normal human fibroblasts in vitro.

PubMed

de Cabo, Rafael; Liu, Lijuan; Ali, Ahmed; Price, Nathan; Zhang, Jing; Wang, Mingyi; Lakatta, Edward; Irusta, Pablo M

2015-03-01

The cumulative effects of cellular senescence and cell loss over time in various tissues and organs are considered major contributing factors to the ageing process. In various organisms, caloric restriction (CR) slows ageing and increases lifespan, at least in part, by activating nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylases of the sirtuin family. Here, we use an in vitro model of CR to study the effects of this dietary regime on replicative senescence, cellular lifespan and modulation of the SIRT1 signaling pathway in normal human diploid fibroblasts. We found that serum from calorie-restricted animals was able to delay senescence and significantly increase replicative lifespan in these cells, when compared to serum from ad libitum fed animals. These effects correlated with CR-mediated increases in SIRT1 and decreases in p53 expression levels. In addition, we show that manipulation of SIRT1 levels by either over-expression or siRNA-mediated knockdown resulted in delayed and accelerated cellular senescence, respectively. Our results demonstrate that CR can delay senescence and increase replicative lifespan of normal human diploid fibroblasts in vitro and suggest that SIRT1 plays an important role in these processes.

Serum from calorie-restricted animals delays senescence and extends the lifespan of normal human fibroblasts in vitro

PubMed Central

Ali, Ahmed; Price, Nathan; Zhang, Jing; Wang, Mingyi; Lakatta, Edward; Irusta, Pablo M.

2015-01-01

The cumulative effects of cellular senescence and cell loss over time in various tissues and organs are considered major contributing factors to the ageing process. In various organisms, caloric restriction (CR) slows ageing and increases lifespan, at least in part, by activating nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylases of the sirtuin family. Here, we use an in vitro model of CR to study the effects of this dietary regime on replicative senescence, cellular lifespan and modulation of the SIRT1 signaling pathway in normal human diploid fibroblasts. We found that serum from calorie-restricted animals was able to delay senescence and significantly increase replicative lifespan in these cells, when compared to serum from ad libitum fed animals. These effects correlated with CR-mediated increases in SIRT1 and decreases in p53 expression levels. In addition, we show that manipulation of SIRT1 levels by either over-expression or siRNA-mediated knockdown resulted in delayed and accelerated cellular senescence, respectively. Our results demonstrate that CR can delay senescence and increase replicative lifespan of normal human diploid fibroblasts in vitro and suggest that SIRT1 plays an important role in these processes. (185 words). PMID:25855056

Self-assembling enzymes and the origins of the cytoskeleton

PubMed Central

Barry, Rachael; Gitai, Zemer

2011-01-01

The bacterial cytoskeleton is composed of a complex and diverse group of proteins that self-assemble into linear filaments. These filaments support and organize cellular architecture and provide a dynamic network controlling transport and localization within the cell. Here, we review recent discoveries related to a newly appreciated class of self-assembling proteins that expand our view of the bacterial cytoskeleton and provide potential explanations for its evolutionary origins. Specifically, several types of metabolic enzymes can form structures similar to established cytoskeletal filaments and, in some cases, these structures have been repurposed for structural uses independent of their normal role. The behaviors of these enzymes suggest that some modern cytoskeletal proteins may have evolved from dual-role proteins with catalytic and structural functions. PMID:22014508

Epigenetic medicine and fetal alcohol spectrum disorders

PubMed Central

Resendiz, Marisol; Chen, Yuanyuan; Öztürk, Nail C; Zhou, Feng C

2013-01-01

Epigenetic medicine is still in its infancy. To date, only a handful of diseases have documented epigenetic correlates upstream of gene regulation including cancer, developmental syndromes and late-onset diseases. The finding that epigenetic markers are dynamic and heterogeneous at tissue and cellular levels, combined with recent identification of a new form of functionally distinct DNA methylation has opened a wider window for investigators to pry into the epigenetic world. It is anticipated that many diseases will be elucidated through this epigenetic inquiry. In this review, we discuss the normal course of DNA methylation during development, taking alcohol as a demonstrator of the epigenetic impact of environmental factors in disease etiology, particularly the growth retardation and neurodevelopmental deficits of fetal alcohol spectrum disorders. PMID:23414322

Lysosomal storage disorders: The cellular impact of lysosomal dysfunction

PubMed Central

2012-01-01

Lysosomal storage diseases (LSDs) are a family of disorders that result from inherited gene mutations that perturb lysosomal homeostasis. LSDs mainly stem from deficiencies in lysosomal enzymes, but also in some non-enzymatic lysosomal proteins, which lead to abnormal storage of macromolecular substrates. Valuable insights into lysosome functions have emerged from research into these diseases. In addition to primary lysosomal dysfunction, cellular pathways associated with other membrane-bound organelles are perturbed in these disorders. Through selective examples, we illustrate why the term “cellular storage disorders” may be a more appropriate description of these diseases and discuss therapies that can alleviate storage and restore normal cellular function. PMID:23185029

Erythrocyte disorders leading to potassium loss and cellular dehydration.

PubMed

Glader, B E; Sullivan, D W

1979-01-01

RBC K loss and cellular dehydration are associated with a variety of normal and abnormal erythrocyte conditions. In some cases (normal RBC aging, pyruvate-kinase-deficient RBCs and irreversibly sickled cells) cation and water changes are related to adenosine triphosphate (ATP) depletion and to increased RBC calcium content. In other disorders, such as hereditary xerocytosis, cation depletion and cellular hydration are not related to altered energy or calcium metabolism. Rather, this condition is thought to be due to a structural membrane defect which is manifested by imbalanced cation leaks (K less greater than Na gain) for which the active cation transport is unable to compensate. None of the disorders described here are associated with known structural membrane alterations. The fact that K loss and cellular dehydration are common to several RBC disorders suggests that this phenomenon may have a direct role in membrane injury. This hypothesis is supported by two separate observations: 1)Formation of irreversible sickled cells in vitro is prevented if K and water loss are inhibited, and these effects are independent of ATP depletion and calcium accumulation; 2) the mean critical hemolytic volume is markedly reduced in K- and water-depleted normal RBCs. RBC dehydration without intracellular cation depletion, however, is not associated with changes in mean critical hemolytic volume. These data thus indicate that K loss may have a direct role in RBC membrane injury. The mechanism by which this occurs and the associated alterations in membrane structure, however, remain to be identified.

The thorny path linking cellular senescence to organismalaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patil, Christopher K.; Mian, Saira; Campisi, Judith

2005-08-09

Half a century is fast approaching since Hayflick and colleagues formally described the limited ability of normal human cells to proliferate in culture (Hayflick and Moorhead, 1961). This finding--that normal somatic cells, in contrast to cancer cells, cannot divide indefinitely--challenged the prevailing idea that cells from mortal multicellular organisms were intrinsically ''immortal'' (Carrell, 1912). It also spawned two hypotheses, essential elements of which persist today. The first held that the restricted proliferation of normal cells, now termed cellular senescence, suppresses cancer (Hayflick, 1965; Sager, 1991; Campisi, 2001). The second hypothesis, as explained in the article by Lorenzini et al., suggestedmore » that the limited proliferation of cells in culture recapitulated aspects of organismal aging (Hayflick, 1965; Martin, 1993). How well have these hypotheses weathered the ensuing decades? Before answering this question, we first consider current insights into the causes and consequences of cellular senescence. Like Lorenzini et al., we limit our discussion to mammals. We also focus on fibroblasts, the cell type studied by Lorenzini et al., but consider other types as well. We suggest that replicative capacity in culture is not a straightforward assessment, and that it correlates poorly with both longevity and body mass. We speculate this is due to the malleable and variable nature of replicative capacity, which renders it an indirect metric of qualitative and quantitative differences among cells to undergo senescence, a response that directly alters cellular phenotype and might indirectly alter tissue structure and function.« less

Microstructural effects in drug release by solid and cellular polymeric dosage forms: A comparative study.

PubMed

Blaesi, Aron H; Saka, Nannaji

2017-11-01

In recent studies, we have introduced melt-processed polymeric cellular dosage forms to achieve both immediate drug release and predictable manufacture. Dosage forms ranging from minimally-porous solids to highly porous, open-cell and thin-walled structures were prepared, and the drug release characteristics investigated as the volume fraction of cells and the excipient molecular weight were varied. In the present study, both minimally-porous solid and cellular dosage forms consisting of various weight fractions of Acetaminophen drug and polyethylene glycol (PEG) excipient are prepared and analyzed. Microstructures of the solid forms and the cell walls range from single-phase solid solutions of the excipient and a small amount of drug molecules to two-phase composites of the excipient and tightly packed drug particles. Results of dissolution experiments show that the minimally-porous solid forms disintegrate and release drug by slow surface erosion. The erosion rate decreases as the drug weight fraction is increased. By contrast, the open-cell structures disintegrate rapidly by viscous exfoliation, and the disintegration time is independent of drug weight fraction. Drug release models suggest that the solid forms erode by convective mass transfer of the faster-eroding excipient if the drug volume fraction is small. At larger drug volume fractions, however, the slower-eroding drug particles hinder access of the free-flowing fluid to the excipient, thus slowing down erosion of the composite. Conversely, the disintegration rate of the cellular forms is limited by diffusion of the dissolution fluid into the excipient phase of the thin cell walls. Because the wall thickness is of the order of the drug particle size, and the particles are enveloped by the excipient during melt-processing, the drug particles cannot hinder diffusion through the excipient across the walls. Thus the disintegration time of the cellular forms is mostly unaffected by the volume fraction of drug in the walls. Copyright © 2017 Elsevier B.V. All rights reserved.

Developmental thyroid hormone insufficiency and brain development: A role for brain-derived neurotrophic factor (BDNF)?*

EPA Science Inventory

Thyroid hormones (TH) are essential for normal brain development. Even subclinical hypothyroidism experienced in utero can result in neuropsychological deficits in children despite normal thyroid status at birth. Neurotrophins have been implicated in a host of brain cellular func...

On the Normal Force Mechanotransduction of Human Umbilical Vein Endothelial Cells

NASA Astrophysics Data System (ADS)

Vahabikashi, Amir; Wang, Qiuyun; Wilson, James; Wu, Qianhong; Vucbmss Team

2016-11-01

In this paper, we report a cellular biomechanics study to examine the normal force mechanotransduction of Human Umbilical Vein Endothelial Cells (HUVECs) with their implications on hypertension. Endothelial cells sense mechanical forces and adjust their structure and function accordingly. The mechanotransduction of normal forces plays a vital role in hypertension due to the higher pressure buildup inside blood vessels. Herein, HUVECs were cultured to full confluency and then exposed to different mechanical loadings using a novel microfluidic flow chamber. One various pressure levels while keeps the shear stress constant inside the flow chamber. Three groups of cells were examined, the control group (neither shear nor normal stresses), the normal pressure group (10 dyne/cm2 of shear stress and 95 mmHg of pressure), and the hypertensive group (10 dyne/cm2 of shear stress and 142 mmHg of pressure). Cellular response characterized by RT-PCR method indicates that, COX-2 expressed under normal pressure but not high pressure; Mn-SOD expressed under both normal and high pressure while this response was stronger for normal pressure; FOS and e-NOS did not respond under any condition. The differential behavior of COX-2 and Mn-SOD in response to changes in pressure, is instrumental for better understanding the pathogenesis of hypertensive cardiovascular diseases. This research was supported by the National Science Foundation under Award #1511096.

The effect of enzymes upon metabolism, storage, and release of carbohydrates in normal and abnormal endometria.

PubMed

Hughes, E C

1976-07-01

This paper presents preliminary data concerning the relationship of various components of glandular epithelium and effect of enzymes on metabolism, storage, and release of certain substances in normal and abnormal endometria. Activity of these endometrial enzymes has been compared between two groups: 252 patients with normal menstrual histories and 156 patients, all over the age of 40, with abnormal uterine bleeding. Material was obtained by endometrial biopsy or curettage. In the pathologic classification of the group of 156, 30 patients had secretory endometria, 88 patients had endometria classified as proliferative, 24 were classified as endometrial hyperplasia, and 14 were classified as adenocarcinoma. All tissue was studied by histologic, histochemical, and biochemical methods. Glycogen synthetase activity caused synthesis of glucose to glycogen, increasing in amount until midcycle, when glycogen phosphorylase activity caused the breakdown to glucose during the regressive stage of endometrial activity. This normal cyclic activity did not occur in the abnormal endometria, where activity of both enzymes continued at low constant tempo. Only the I form of glycogen synthetase increased as the tissue became more hyperplastic. With the constant glycogen content and the increased activity of both the TPN isocitric dehydrogenase and glucose-6-phosphate dehydrogenase in the hyperplastic and cancerous endometria, tissue energy was created, resulting in abnormal cell proliferation. These altered biochemical and cellular activities may be the basis for malignant cell growth.

Effect of resveratrol and zinc on intracellular zinc status in normal human prostate epithelial cells

USDA-ARS?s Scientific Manuscript database

To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated with 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 microM) and 4 levels of zinc [0, 4, 16, and 32 microM for zinc-deficient (ZD), zinc-normal (ZN), zinc-adequate (ZA), an...

Common pediatric cerebellar tumors: correlation between cell densities and apparent diffusion coefficient metrics.

PubMed

Koral, Korgün; Mathis, Derek; Gimi, Barjor; Gargan, Lynn; Weprin, Bradley; Bowers, Daniel C; Margraf, Linda

2013-08-01

To test whether there is correlation between cell densities and apparent diffusion coefficient (ADC) metrics of common pediatric cerebellar tumors. This study was reviewed for issues of patient safety and confidentiality and was approved by the Institutional Review Board of the University of Texas Southwestern Medical Center and was compliant with HIPAA. The need for informed consent was waived. Ninety-five patients who had preoperative magnetic resonance imaging and surgical pathologic findings available between January 2003 and June 2011 were included. There were 37 pilocytic astrocytomas, 34 medulloblastomas (23 classic, eight desmoplastic-nodular, two large cell, one anaplastic), 17 ependymomas (13 World Health Organization [WHO] grade II, four WHO grade III), and seven atypical teratoid rhabdoid tumors. ADCs of solid tumor components and normal cerebellum were measured. Tumor-to-normal brain ADC ratios (hereafter, ADC ratio) were calculated. The medulloblastomas and ependymomas were subcategorized according to the latest WHO classification, and tumor cellularity was calculated. Correlation was sought between cell densities and mean tumor ADCs, minimum tumor ADCs, and ADC ratio. When all tumors were considered together, negative correlation was found between cellularity and mean tumor ADCs (ρ = -0.737, P < .05) and minimum tumor ADCs (ρ = -0.736, P < .05) of common pediatric cerebellar tumors. There was no correlation between cellularity and ADC ratio. Negative correlation was found between cellularity and minimum tumor ADC in atypical teratoid rhabdoid tumors (ρ = -0.786, P < .05). In atypical teratoid rhabdoid tumors, no correlation was found between cellularity and mean tumor ADC and ADC ratio. There was no correlation between the ADC metrics and cellularity of the pilocytic astrocytomas, medulloblastomas, and ependymomas. Negative correlation was found between cellularity and ADC metrics of common pediatric cerebellar tumors. Although ADC metrics are useful in the preoperative diagnosis of common pediatric cerebellar tumors and this utility is generally attributed to differences in cellularity of tumors, tumor cellularity may not be the sole determinant of the differences in diffusivity.

Leukopenia and altered hematopoietic activity in mice exposed to the abused inhalant, isobutyl nitrite.

PubMed

Soderberg, L S; Flick, J T; Barnett, J B

1996-06-01

Isobutyl nitrite is representative of a group of inhalants abused primarily by male homosexuals; abuse of this drug may be a risk factor for AIDS or Kaposi's sarcoma. Using a 14-day exposure regimen, we previously reported that inhaled isobutyl nitrite was immunotoxic to mice, severely compromising T-dependent antibody responses and cytotoxic T cell and macrophage tumoricidal activity. In addition, exposure to the inhalant dramatically reduced spleen cellularity. A single 45-minute inhalation exposure produced anemia in mice. In the present study, we examined the effects of subchronic exposure to the drug on peripheral blood cellularity and hematopoietic activity. Mice were exposed to 900 ppm isobutyl nitrite in an inhalation chamber for 45 minutes/day for 14 days. One day after the final exposure, the number of peripheral blood leukocytes was reduced by 32%; however, the number of erythrocytes was increased by 7%. This was accompanied by an apparent shift from myelopoiesis to erythropoiesis. The numbers of bone marrow and spleen burst-forming units-erythroid (BFU-E) were increased about two-fold, while the numbers of colony-forming units-granulocyte/macrophage (CFU-GM) were decreased by about half. Bone marrow stromal cells also had reductions in the production of myeloid colony-stimulating activity after subchronic exposure to the inhalant. In addition, the numbers of hematopoietic stem cells, colony-forming units-spleen (CFU-S), were reduced in both bone marrow and spleen. Peripheral blood erythrocyte and leukocyte counts returned to normal levels by 7 days after the final exposure, as did the number of BFU-E. The number of CFU-GM remained depressed, however, even after 7 days of recovery. These data suggest that repeated exposures nonspecifically depleted cells and that erythropoiesis was stimulated, apparently at the expense of myelopoiesis.

Folic acid and L-5-methyltetrahydrofolate: comparison of clinical pharmacokinetics and pharmacodynamics.

PubMed

Pietrzik, Klaus; Bailey, Lynn; Shane, Barry

2010-08-01

There is a large body of evidence to suggest that improving periconceptional folate status reduces the risk of neonatal neural tube defects. Thus increased folate intake is now recommended before and during the early stages of pregnancy, through folic acid supplements or fortified foods. Furthermore, there is growing evidence that folic acid may have a role in the prevention of other diseases, including dementia and certain types of cancer. Folic acid is a synthetic form of the vitamin, which is only found in fortified foods, supplements and pharmaceuticals. It lacks coenzyme activity and must be reduced to the metabolically active tetrahydrofolate form within the cell. L-5-methyl-tetrahydrofolate (L-5-methyl-THF) is the predominant form of dietary folate and the only species normally found in the circulation, and hence it is the folate that is normally transported into peripheral tissues to be used for cellular metabolism. L-5-methyl-THF is also available commercially as a crystalline form of the calcium salt (Metafolin(R)), which has the stability required for use as a supplement. Studies comparing L-5-methyl-THF and folic acid have found that the two compounds have comparable physiological activity, bioavailability and absorption at equimolar doses. Bioavailability studies have provided strong evidence that L-5-methyl-THF is at least as effective as folic acid in improving folate status, as measured by blood concentrations of folate and by functional indicators of folate status, such as plasma homocysteine. Intake of L-5-methyl-THF may have advantages over intake of folic acid. First, the potential for masking the haematological symptoms of vitamin B(12) deficiency may be reduced with L-5-methyl-THF. Second, L-5-methyl-THF may be associated with a reduced interaction with drugs that inhibit dihydrofolate reductase.

Simulation of root forms using cellular automata model

NASA Astrophysics Data System (ADS)

Winarno, Nanang; Prima, Eka Cahya; Afifah, Ratih Mega Ayu

2016-02-01

This research aims to produce a simulation program for root forms using cellular automata model. Stephen Wolfram in his book entitled "A New Kind of Science" discusses the formation rules based on the statistical analysis. In accordance with Stephen Wolfram's investigation, the research will develop a basic idea of computer program using Delphi 7 programming language. To best of our knowledge, there is no previous research developing a simulation describing root forms using the cellular automata model compared to the natural root form with the presence of stone addition as the disturbance. The result shows that (1) the simulation used four rules comparing results of the program towards the natural photographs and each rule had shown different root forms; (2) the stone disturbances prevent the root growth and the multiplication of root forms had been successfully modeled. Therefore, this research had added some stones, which have size of 120 cells placed randomly in the soil. Like in nature, stones cannot be penetrated by plant roots. The result showed that it is very likely to further develop the program of simulating root forms by 50 variations.

The microprotein Minion controls cell fusion and muscle formation

PubMed Central

Zhang, Qiao; Vashisht, Ajay A.; O'Rourke, Jason; Corbel, Stéphane Y; Moran, Rita; Romero, Angelica; Miraglia, Loren; Zhang, Jia; Durrant, Eric; Schmedt, Christian; Sampath, Srinath C.; Sampath, Srihari C.

2017-01-01

Although recent evidence has pointed to the existence of small open reading frame (smORF)-encoded microproteins in mammals, their function remains to be determined. Skeletal muscle development requires fusion of mononuclear progenitors to form multinucleated myotubes, a critical but poorly understood process. Here we report the identification of Minion (microprotein inducer of fusion), a smORF encoding an essential skeletal muscle specific microprotein. Myogenic progenitors lacking Minion differentiate normally but fail to form syncytial myotubes, and Minion-deficient mice die perinatally and demonstrate a marked reduction in fused muscle fibres. The fusogenic activity of Minion is conserved in the human orthologue, and co-expression of Minion and the transmembrane protein Myomaker is sufficient to induce cellular fusion accompanied by rapid cytoskeletal rearrangement, even in non-muscle cells. These findings establish Minion as a novel microprotein required for muscle development, and define a two-component programme for the induction of mammalian cell fusion. Moreover, these data also significantly expand the known functions of smORF-encoded microproteins. PMID:28569745

Value of transmission electron microscopy for primary ciliary dyskinesia diagnosis in the era of molecular medicine: Genetic defects with normal and non-diagnostic ciliary ultrastructure.

PubMed

Shapiro, Adam J; Leigh, Margaret W

2017-01-01

Primary ciliary dyskinesia (PCD) is a genetic disorder causing chronic oto-sino-pulmonary disease. No single diagnostic test will detect all PCD cases. Transmission electron microscopy (TEM) of respiratory cilia was previously considered the gold standard diagnostic test for PCD, but 30% of all PCD cases have either normal ciliary ultrastructure or subtle changes which are non-diagnostic. These cases are identified through alternate diagnostic tests, including nasal nitric oxide measurement, high-speed videomicroscopy analysis, immunofluorescent staining of axonemal proteins, and/or mutation analysis of various PCD causing genes. Autosomal recessive mutations in DNAH11 and HYDIN produce normal TEM ciliary ultrastructure, while mutations in genes encoding for radial spoke head proteins result in some cross-sections with non-diagnostic alterations in the central apparatus interspersed with normal ciliary cross-sections. Mutations in nexin link and dynein regulatory complex genes lead to a collection of different ciliary ultrastructures; mutations in CCDC65, CCDC164, and GAS8 produce normal ciliary ultrastructure, while mutations in CCDC39 and CCDC40 cause absent inner dynein arms and microtubule disorganization in some ciliary cross-sections. Mutations in CCNO and MCIDAS cause near complete absence of respiratory cilia due to defects in generation of multiple cellular basal bodies; however, the scant cilia generated may have normal ultrastructure. Lastly, a syndromic form of PCD with retinal degeneration results in normal ciliary ultrastructure through mutations in the RPGR gene. Clinicians must be aware of these genetic causes of PCD resulting in non-diagnostic TEM ciliary ultrastructure and refrain from using TEM of respiratory cilia as a test to rule out PCD.

A Novel Isoform of the B Cell Tyrosine Kinase BTK Protects Breast Cancer Cells from Apoptosis

PubMed Central

Eifert, Cheryl; Wang, Xianhui; Kokabee, Leila; Kourtidis, Antonis; Jain, Ritu; Gerdes, Michael J.; Conklin, Douglas S.

2016-01-01

Tyrosine kinases orchestrate key cellular signaling pathways and their dysregulation is often associated with cellular transformation. Several recent cases in which inhibitors of tyrosine kinases have been successfully used as anticancer agents have underscored the importance of this class of proteins in the development of targeted cancer therapies. We have carried out a large-scale loss-of-function analysis of the human tyrosine kinases using RNA interference to identify novel survival factors for breast cancer cells. In addition to kinases with known roles in breast and other cancers, we identified several kinases that were previously unknown to be required for breast cancer cell survival. The most surprising of these was the cytosolic, nonreceptor tyrosine kinase, Bruton’s tyrosine kinase (BTK), which has been extensively studied in B cell development. Down regulation of this protein with RNAi or inhibition with pharmacological inhibitors causes apoptosis; overexpression inhibits apoptosis induced by Doxorubicin in breast cancer cells. Our results surprisingly show that BTK is expressed in several breast cancer cell lines and tumors. The predominant form of BTK found in tumor cells is transcribed from an alternative promoter and results in a protein with an amino-terminal extension. This alternate form of BTK is expressed at significantly higher levels in tumorigenic breast cells than in normal breast cells. Since this protein is a survival factor for these cells, it represents both a potential marker and novel therapeutic target for breast cancer. PMID:23913792

Nitrosative Stress in the Nervous System: Guidelines for Designing Experimental Strategies to Study Protein S-Nitrosylation.

PubMed

Nakamura, Tomohiro; Lipton, Stuart A

2016-03-01

Reactive nitrogen species, such as nitric oxide (NO), exert their biological activity in large part through post-translational modification of cysteine residues, forming S-nitrosothiols. This chemical reaction proceeds via a process that we and our colleagues have termed protein S-nitrosylation. Under conditions of normal NO production, S-nitrosylation regulates the activity of many normal proteins. However, in degenerative conditions characterized by nitrosative stress, increased levels of NO lead to aberrant S-nitrosylation that contributes to the pathology of the disease. Thus, S-nitrosylation has been implicated in a wide range of cellular mechanisms, including mitochondrial function, proteostasis, transcriptional regulation, synaptic activity, and cell survival. In recent years, the research area of protein S-nitrosylation has become prominent due to improvements in the detection systems as well as the demonstration that protein S-nitrosylation plays a critical role in the pathogenesis of neurodegenerative and other neurological disorders. To further promote our understanding of how protein S-nitrosylation affects cellular systems, guidelines for the design and conduct of research on S-nitrosylated (or SNO-)proteins would be highly desirable, especially for those newly entering the field. In this review article, we provide a strategic overview of designing experimental approaches to study protein S-nitrosylation. We specifically focus on methods that can provide critical data to demonstrate that an S-nitrosylated protein plays a (patho-)physiologically-relevant role in a biological process. Hence, the implementation of the approaches described herein will contribute to further advancement of the study of S-nitrosylated proteins, not only in neuroscience but also in other research fields.

Tenascin-C and mechanotransduction in the development and diseases of cardiovascular system

PubMed Central

Imanaka-Yoshida, Kyoko; Aoki, Hiroki

2014-01-01

Living tissue is composed of cells and extracellular matrix (ECM). In the heart and blood vessels, which are constantly subjected to mechanical stress, ECM molecules form well-developed fibrous frameworks to maintain tissue structure. ECM is also important for biological signaling, which influences various cellular functions in embryonic development, and physiological/pathological responses to extrinsic stimuli. Among ECM molecules, increased attention has been focused on matricellular proteins. Matricellular proteins are a growing group of non-structural ECM proteins highly up-regulated at active tissue remodeling, serving as biological mediators. Tenascin-C (TNC) is a typical matricellular protein, which is highly expressed during embryonic development, wound healing, inflammation, and cancer invasion. The expression is tightly regulated, dependent on the microenvironment, including various growth factors, cytokines, and mechanical stress. In the heart, TNC appears in a spatiotemporal-restricted manner during early stages of development, sparsely detected in normal adults, but transiently re-expressed at restricted sites associated with tissue injury and inflammation. Similarly, in the vascular system, TNC is strongly up-regulated during embryonic development and under pathological conditions with an increase in hemodynamic stress. Despite its intriguing expression pattern, cardiovascular system develops normally in TNC knockout mice. However, deletion of TNC causes acute aortic dissection (AAD) under strong mechanical and humoral stress. Accumulating reports suggest that TNC may modulate the inflammatory response and contribute to elasticity of the tissue, so that it may protect cardiovascular tissue from destructive stress responses. TNC may be a key molecule to control cellular activity during development, adaptation, or pathological tissue remodeling. PMID:25120494

Convergent synaptic and circuit substrates underlying autism genetic risks.

PubMed

McGee, Aaron; Li, Guohui; Lu, Zhongming; Qiu, Shenfeng

2014-02-01

There has been a surge of diagnosis of autism spectrum disorders (ASD) over the past decade. While large, high powered genome screening studies of children with ASD have identified numerous genetic risk factors, research efforts to understanding how each of these risk factors contributes to the development autism has met with limited success. Revealing the mechanisms by which these genetic risk factors affect brain development and predispose a child to autism requires mechanistic understanding of the neurobiological changes underlying this devastating group of developmental disorders at multifaceted molecular, cellular and system levels. It has been increasingly clear that the normal trajectory of neurodevelopment is compromised in autism, in multiple domains as much as aberrant neuronal production, growth, functional maturation, patterned connectivity, and balanced excitation and inhibition of brain networks. Many autism risk factors identified in humans have been now reconstituted in experimental mouse models to allow mechanistic interrogation of the biological role of the risk gene. Studies utilizing these mouse models have revealed that underlying the enormous heterogeneity of perturbed cellular events, mechanisms directing synaptic and circuit assembly may provide a unifying explanation for the pathophysiological changes and behavioral endophenotypes seen in autism, although synaptic perturbations are far from being the only alterations relevant for ASD. In this review, we discuss synaptic and circuit abnormalities obtained from several prevalent mouse models, particularly those reflecting syndromic forms of ASD that are caused by single gene perturbations. These compiled results reveal that ASD risk genes contribute to proper signaling of the developing gene networks that maintain synaptic and circuit homeostasis, which is fundamental to normal brain development.

Molecular genetic characterization of the RD-114 gene family of endogenous feline retroviral sequences.

PubMed Central

Reeves, R H; O'Brien, S J

1984-01-01

RD-114 is a replication-competent, xenotropic retrovirus which is homologous to a family of moderately repetitive DNA sequences present at ca. 20 copies in the normal cellular genome of domestic cats. To examine the extent and character of genomic divergence of the RD-114 gene family as well as to assess their positional association within the cat genome, we have prepared a series of molecular clones of endogenous RD-114 DNA segments from a genomic library of cat cellular DNA. Their restriction endonuclease maps were compared with each other as well as to that of the prototype-inducible RD-114 which was molecularly cloned from a chronically infected human cell line. The endogenous sequences analyzed were similar to each other in that they were colinear with RD-114 proviral DNA, were bounded by long terminal redundancies, and conserved many restriction sites in the gag and pol regions. However, the env regions of many of the sequences examined were substantially deleted. Several of the endogenous RD-114 genomes contained a novel envelope sequence which was unrelated to the env gene of the prototype RD-114 env gene but which, like RD-114 and endogenous feline leukemia virus provirus, was found only in species of the genus Felis, and not in other closely related Felidae genera. The endogenous RD-114 sequences each had a distinct cellular flank which indicates that these sequences are not tandem but dispersed nonspecifically throughout the genome. Southern analysis of cat cellular DNA confirmed the conclusions about conserved restriction sites in endogenous sequences and indicated that a single locus may be responsible for the production of the major inducible form of RD-114. Images PMID:6090693

Cellular Sites of Immunologic Unresponsiveness*

PubMed Central

Chiller, Jacques M.; Habicht, Gail S.; Weigle, William O.

1970-01-01

The reconstitution of the immune response of lethally irradiated mice to human γ-globulin is dependent on the synergistic action of bone marrow with thymus cells. Immunologic unresponsiveness appears to involve a functional defect at each of these cellular levels, inasmuch as neither bone marrow nor thymus cells from unresponsive donors are capable of demonstrating synergism in combination with their normal counterpart. PMID:4192271

On the cellular autoimmune mechanism for eliminating erythrocytes normally and under extreme influences

NASA Technical Reports Server (NTRS)

Pukhova, Y. I.; Terskov, I. A.; Anikina, A. Y.; Shashkin, A. V.

1980-01-01

The presence of an autoimmune cellular mechanism for destroying erythrocytes on the basis of results of experiments in vivo is demonstrated in the blood and the organs. This mechanism is made up of a population of immunocompetent killer-lymphocytes which originates in the bone marrow and the thymus, and which is manifested in the local hemolysis effect.

Povidone-Iodine Has a Profound Effect on In Vitro Osteoblast Proliferation and Metabolic Function and Inhibits Their Ability to Mineralize and Form Bone.

PubMed

Newton Ede, Matthew P; Philp, Ashleigh M; Philp, Andrew; Richardson, Stephen M; Mohammad, Saeed; Jones, Simon W

2016-05-01

A study examining the clinical protocol of scoliosis wound irrigation, demonstrating povidone-iodine's (PVI) effect on human osteoblast cells. Primary and immortal cell line osteoblasts were treated with 0.35% PVI for 3 minutes, and analyzed for proliferation rate, oxidative capacity, and mineralization. To model spinal wound irrigation with dilute PVI in vitro, in order to investigate the effect of PVI on osteoblast proliferation, metabolism, and bone mineralization. Previously PVI irrigation has been proposed as a safe and effective practice to avoid bacterial growth after spinal surgery. However, recent evidence in multiple cell types suggests that PVI has a deleterious effect on cellular viability and cellular function. Primary and immortal human osteoblast cells were exposed to either phosphate buffered saline control or with 0.35% PVI for 3 minutes. Cellular proliferation was measured over the duration of 7 days by MTS assay. Oxygen consumption rate, extracellular acidification rate, and proton production rate were analyzed using a Seahorse XF24 Bioanalyzer. Protein expression of the electron transport chain subunits CII-SDHB, CIII-UQRCR2, and CV-ATP5A was measured via Western blotting. Mineralized bone nodules were stained with alizarin red. Expressed as a percentage of normal osteoblast proliferation, osteoblasts exposed to 0.35% PVI exhibited a significant 24% decrease in proliferation after 24 hours. This was a sustained response, resulting in a 72% decline in cellular proliferation at 1 week. There was a significant reduction in oxygen consumption rate, extracellular acidification rate, and proton production rate (P < 0.05), in osteoblasts that had been exposed to 0.35% PVI for 3 minutes, coupled with a marked reduction in the protein expression of CII-SDHB. Osteoblasts exposed to 0.35% PVI exhibited reduced bone nodule mineralization compared to control phosphate buffered saline exposed osteoblasts (P < 0.01). PVI has a rapid and detrimental effect on human osteoblast cellular proliferation, metabolic function, and bone nodule mineralization. NA.

Nanoparticle strategies for cancer therapeutics: Nucleic acids, polyamines, bovine serum amine oxidase and iron oxide nanoparticles (Review).

PubMed

Agostinelli, Enzo; Vianello, Fabio; Magliulo, Giuseppe; Thomas, Thresia; Thomas, T J

2015-01-01

Nanotechnology for cancer gene therapy is an emerging field. Nucleic acids, polyamine analogues and cytotoxic products of polyamine oxidation, generated in situ by an enzyme-catalyzed reaction, can be developed for nanotechnology-based cancer therapeutics with reduced systemic toxicity and improved therapeutic efficacy. Nucleic acid-based gene therapy approaches depend on the compaction of DNA/RNA to nanoparticles and polyamine analogues are excellent agents for the condensation of nucleic acids to nanoparticles. Polyamines and amine oxidases are found in higher levels in tumours compared to that of normal tissues. Therefore, the metabolism of polyamines spermidine and spermine, and their diamine precursor, putrescine, can be targets for antineoplastic therapy since these naturally occurring alkylamines are essential for normal mammalian cell growth. Intracellular polyamine concentrations are maintained at a cell type-specific set point through the coordinated and highly regulated interplay between biosynthesis, transport, and catabolism. In particular, polyamine catabolism involves copper-containing amine oxidases. Several studies showed an important role of these enzymes in developmental and disease-related processes in animals through the control of polyamine homeostasis in response to normal cellular signals, drug treatment, and environmental and/or cellular stress. The production of toxic aldehydes and reactive oxygen species (ROS), H2O2 in particular, by these oxidases suggests a mechanism by which amine oxidases can be exploited as antineoplastic drug targets. The combination of bovine serum amine oxidase (BSAO) and polyamines prevents tumour growth, particularly well if the enzyme has been conjugated with a biocompatible hydrogel polymer. The findings described herein suggest that enzymatically formed cytotoxic agents activate stress signal transduction pathways, leading to apoptotic cell death. Consequently, superparamagnetic nanoparticles or other advanced nanosystem based on directed nucleic acid assemblies, polyamine-induced DNA condensation, and bovine serum amine oxidase may be proposed for futuristic anticancer therapy utilizing nucleic acids, polyamines and BSAO. BSAO based nanoparticles can be employed for the generation of cytotoxic polyamine metabolites.

A grid matrix-based Raman spectroscopic method to characterize different cell milieu in biopsied axillary sentinel lymph nodes of breast cancer patients.

PubMed

Som, Dipasree; Tak, Megha; Setia, Mohit; Patil, Asawari; Sengupta, Amit; Chilakapati, C Murali Krishna; Srivastava, Anurag; Parmar, Vani; Nair, Nita; Sarin, Rajiv; Badwe, R

2016-01-01

Raman spectroscopy which is based upon inelastic scattering of photons has a potential to emerge as a noninvasive bedside in vivo or ex vivo molecular diagnostic tool. There is a need to improve the sensitivity and predictability of Raman spectroscopy. We developed a grid matrix-based tissue mapping protocol to acquire cellular-specific spectra that also involved digital microscopy for localizing malignant and lymphocytic cells in sentinel lymph node biopsy sample. Biosignals acquired from specific cellular milieu were subjected to an advanced supervised analytical method, i.e., cross-correlation and peak-to-peak ratio in addition to PCA and PC-LDA. We observed decreased spectral intensity as well as shift in the spectral peaks of amides and lipid bands in the completely metastatic (cancer cells) lymph nodes with high cellular density. Spectral library of normal lymphocytes and metastatic cancer cells created using the cellular specific mapping technique can be utilized to create an automated smart diagnostic tool for bench side screening of sampled lymph nodes. Spectral library of normal lymphocytes and metastatic cancer cells created using the cellular specific mapping technique can be utilized to develop an automated smart diagnostic tool for bench side screening of sampled lymph nodes supported by ongoing global research in developing better technology and signal and big data processing algorithms.

The cellular source for APOBEC3G's incorporation into HIV-1

PubMed Central

2011-01-01

Background Human APOBEC3G (hA3G) has been identified as a cellular inhibitor of HIV-1 infectivity. Viral incorporation of hA3G is an essential step for its antiviral activity. Although the mechanism underlying hA3G virion encapsidation has been investigated extensively, the cellular source of viral hA3G remains unclear. Results Previous studies have shown that hA3G forms low-molecular-mass (LMM) and high-molecular-mass (HMM) complexes. Our work herein provides evidence that the majority of newly-synthesized hA3G interacts with membrane lipid raft domains to form Lipid raft-associated hA3G (RA hA3G), which serve as the precursor of the mature HMM hA3G complex, while a minority of newly-synthesized hA3G remains in the cytoplasm as a soluble LMM form. The distribution of hA3G among the soluble LMM form, the RA LMM form and the mature forms of HMM is regulated by a mechanism involving the N-terminal part of the linker region and the C-terminus of hA3G. Mutagenesis studies reveal a direct correlation between the ability of hA3G to form the RA LMM complex and its viral incorporation. Conclusions Together these data suggest that the Lipid raft-associated LMM A3G complex functions as the cellular source of viral hA3G. PMID:21211018

Log Normal Distribution of Cellular Uptake of Radioactivity: Statistical Analysis of Alpha Particle Track Autoradiography

PubMed Central

Neti, Prasad V.S.V.; Howell, Roger W.

2008-01-01

Recently, the distribution of radioactivity among a population of cells labeled with 210Po was shown to be well described by a log normal distribution function (J Nucl Med 47, 6 (2006) 1049-1058) with the aid of an autoradiographic approach. To ascertain the influence of Poisson statistics on the interpretation of the autoradiographic data, the present work reports on a detailed statistical analyses of these data. Methods The measured distributions of alpha particle tracks per cell were subjected to statistical tests with Poisson (P), log normal (LN), and Poisson – log normal (P – LN) models. Results The LN distribution function best describes the distribution of radioactivity among cell populations exposed to 0.52 and 3.8 kBq/mL 210Po-citrate. When cells were exposed to 67 kBq/mL, the P – LN distribution function gave a better fit, however, the underlying activity distribution remained log normal. Conclusions The present analysis generally provides further support for the use of LN distributions to describe the cellular uptake of radioactivity. Care should be exercised when analyzing autoradiographic data on activity distributions to ensure that Poisson processes do not distort the underlying LN distribution. PMID:16741316

Roles of the Drosophila LRRK2 homolog in Rab7-dependent lysosomal positioning.

PubMed

Dodson, Mark W; Zhang, Ting; Jiang, Changan; Chen, Shengdi; Guo, Ming

2012-03-15

LRRK2 (PARK8) is the most common genetic determinant of Parkinson's disease (PD), with dominant mutations in LRRK2 causing inherited PD and sequence variation at the LRRK2 locus associated with increased risk for sporadic PD. Although LRRK2 has been implicated in diverse cellular processes encompassing almost all cellular compartments, the precise functions of LRRK2 remain unclear. Here, we show that the Drosophila homolog of LRRK2 (Lrrk) localizes to the membranes of late endosomes and lysosomes, physically interacts with the crucial mediator of late endosomal transport Rab7 and negatively regulates rab7-dependent perinuclear localization of lysosomes. We also show that a mutant form of lrrk analogous to the pathogenic LRRK2(G2019S) allele behaves oppositely to wild-type lrrk in that it promotes rather than inhibits rab7-dependent perinuclear lysosome clustering, with these effects of mutant lrrk on lysosome position requiring both microtubules and dynein. These data suggest that LRRK2 normally functions in Rab7-dependent lysosomal positioning, and that this function is disrupted by the most common PD-causing LRRK2 mutation, linking endolysosomal dysfunction to the pathogenesis of LRRK2-mediated PD.

Cellular redox dysfunction in the development of cardiovascular diseases.

PubMed

Kanaan, Georges N; Harper, Mary-Ellen

2017-11-01

To meet its exceptionally high energy demands, the heart relies largely on fatty acid oxidation, which then drives the oxidative phosphorylation system in mitochondria. Each day, this system produces about 6kg of ATP to sustain heart function. Fatty acid oxidation is sometimes associated with high rates of mitochondrial reactive oxygen species (ROS) production. By definition, ROS are singlet electron intermediates formed during the partial reduction of oxygen to water and they include radical and non-radical intermediates like superoxide, hydrogen peroxide and hydroxyl radical. Superoxide can also interact with nitric oxide to produce peroxynitrite that in turn can give rise to other radical or non-radical reactive nitrogen species (RNS) like nitrogen dioxide, dinitrogen trioxide and others. While mitochondrial and cellular functions can be impaired by ROS if they accumulate, under normal physiological conditions ROS are important signaling molecules in the cardiovascular system. A fine balance between ROS production and antioxidant systems, including glutathione redox, is essential in the heart; otherwise the ensuing damage can contribute to pathogenic processes, which can culminate in endothelial dysfunction, atherosclerosis, hypertension, cardiac hypertrophy, arrhythmias, myocardial ischemia/reperfusion damage, and heart failure. Here we provide a succinct review of recent findings. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of traffic congestion induced by the work zone

NASA Astrophysics Data System (ADS)

Fei, L.; Zhu, H. B.; Han, X. L.

2016-05-01

Based on the cellular automata model, a meticulous two-lane cellular automata model is proposed, in which the driving behavior difference and the difference of vehicles' accelerations between the moving state and the starting state are taken into account. Furthermore the vehicles' motion is refined by using the small cell of one meter long. Then accompanied by coming up with a traffic management measure, a two-lane highway traffic model containing a work zone is presented, in which the road is divided into normal area, merging area and work zone. The vehicles in different areas move forward according to different lane changing rules and position updating rules. After simulation it is found that when the density is small the cluster length in front of the work zone increases with the decrease of the merging probability. Then the suitable merging length and the appropriate speed limit value are recommended. The simulation result in the form of the speed-flow diagram is in good agreement with the empirical data. It indicates that the presented model is efficient and can partially reflect the real traffic. The results may be meaningful for traffic optimization and road construction management.

Interaction with culture medium components, cellular uptake and intracellular distribution of cobalt nanoparticles, microparticles and ions in Balb/3T3 mouse fibroblasts.

PubMed

Sabbioni, Enrico; Fortaner, Salvador; Farina, Massimo; Del Torchio, Riccardo; Petrarca, Claudia; Bernardini, Giovanni; Mariani-Costantini, Renato; Perconti, Silvia; Di Giampaolo, Luca; Gornati, Rosalba; Di Gioacchino, Mario

2014-02-01

The mechanistic understanding of nanotoxicity requires the physico-chemical characterisation of nanoparticles (NP), and their comparative investigation relative to the corresponding ions and microparticles (MP). Following this approach, the authors studied the dissolution, interaction with medium components, bioavailability in culture medium, uptake and intracellular distribution of radiolabelled Co forms (CoNP, CoMP and Co(2+)) in Balb/3T3 mouse fibroblasts. Co(2+) first saturates the binding sites of molecules in the extracellular milieu (e.g., albumin and histidine) and on the cell surface. Only after saturation, Co(2+) is actively uptaken. CoNP, instead, are predicted to be internalised by endocytosis. Dissolution of Co particles allows the formation of Co compounds (CoNP-rel), whose mechanism of cellular internalisation is unknown. Co uptake (ranking CoMP > CoNP > Co(2+)) reached maximum at 4 h. Once inside the cell, CoNP spread into the cytosol and organelles. Consequently, massive amounts of Co ions and CoNP-rel can reach subcellular compartments normally unexposed to Co(2+). This could explain the fact that the nuclear and mitochondrial Co concentrations resulted significantly higher than those obtained with Co(2+).

Protein and cell micropatterning and its integration with micro/nanoparticles assembly.

PubMed

Yap, F L; Zhang, Y

2007-01-15

Micropatterning of proteins and cells has become very popular over the past decade due to its importance in the development of biosensors, microarrays, tissue engineering and cellular studies. This article reviews the techniques developed for protein and cell micropatterning and its biomedical applications. The prospect of integrating micro and nanoparticles with protein and cell micropatterning is discussed. The micro/nanoparticles are assembled into patterns and form the substrate for proteins and cell attachment. The assembled particles create a micro or nanotopography, depending on the size of the particles employed. The nonplanar structure can increase the surface area for biomolecules attachment and therefore enhance the sensitivity for detection in biosensors. Furthermore, a nanostructured substrate can influence the conformation and functionality of protein attached to it, while cellular response in terms of morphology, adhesion, proliferation, differentiation, etc. can be affected by a surface expressing micro or nanoscale structures. Proteins and cells tend to lose their normal functions upon attachment to substrate. By recognizing the types of topography that are favourable for preserving proteins and cell behaviour, and integrating it with micropattering will lead to the development of functional protein and cell patterns.

GCK-MODY diabetes as a protein misfolding disease: the mutation R275C promotes protein misfolding, self-association and cellular degradation.

PubMed

Negahdar, Maria; Aukrust, Ingvild; Molnes, Janne; Solheim, Marie H; Johansson, Bente B; Sagen, Jørn V; Dahl-Jørgensen, Knut; Kulkarni, Rohit N; Søvik, Oddmund; Flatmark, Torgeir; Njølstad, Pål R; Bjørkhaug, Lise

2014-01-25

GCK-MODY, dominantly inherited mild hyperglycemia, is associated with more than 600 mutations in the glucokinase gene. Different molecular mechanisms have been shown to explain GCK-MODY. Here, we report a Pakistani family harboring the glucokinase mutation c.823C>T (p.R275C). The recombinant and in cellulo expressed mutant pancreatic enzyme revealed slightly increased enzyme activity (kcat) and normal affinity for α-D-glucose, and resistance to limited proteolysis by trypsin comparable with wild-type. When stably expressed in HEK293 cells and MIN6 β-cells (at different levels), the mutant protein appeared misfolded and unstable with a propensity to form dimers and aggregates. Its degradation rate was increased, involving the lysosomal and proteasomal quality control systems. On mutation, a hydrogen bond between the R275 side-chain and the carbonyl oxygen of D267 is broken, destabilizing the F260-L271 loop structure and the protein. This promotes the formation of dimers/aggregates and suggests that an increased cellular degradation is the molecular mechanism by which R275C causes GCK-MODY. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Roles of the Drosophila LRRK2 homolog in Rab7-dependent lysosomal positioning

PubMed Central

Dodson, Mark W.; Zhang, Ting; Jiang, Changan; Chen, Shengdi; Guo, Ming

2012-01-01

LRRK2 (PARK8) is the most common genetic determinant of Parkinson's disease (PD), with dominant mutations in LRRK2 causing inherited PD and sequence variation at the LRRK2 locus associated with increased risk for sporadic PD. Although LRRK2 has been implicated in diverse cellular processes encompassing almost all cellular compartments, the precise functions of LRRK2 remain unclear. Here, we show that the Drosophila homolog of LRRK2 (Lrrk) localizes to the membranes of late endosomes and lysosomes, physically interacts with the crucial mediator of late endosomal transport Rab7 and negatively regulates rab7-dependent perinuclear localization of lysosomes. We also show that a mutant form of lrrk analogous to the pathogenic LRRK2G2019S allele behaves oppositely to wild-type lrrk in that it promotes rather than inhibits rab7-dependent perinuclear lysosome clustering, with these effects of mutant lrrk on lysosome position requiring both microtubules and dynein. These data suggest that LRRK2 normally functions in Rab7-dependent lysosomal positioning, and that this function is disrupted by the most common PD-causing LRRK2 mutation, linking endolysosomal dysfunction to the pathogenesis of LRRK2-mediated PD. PMID:22171073

Crk1/2 and CrkL form a hetero-oligomer and functionally complement each other during podocyte morphogenesis

PubMed Central

Zhang, Jidong; Verma, Rakesh; Park, Tae-Ju; Wong, Hetty; Curran, Tom; Nihalani, Deepak; Holzman, Lawrence B.

2014-01-01

Activation of the slit diaphragm protein Nephrin induces actin cytoskeletal remodeling resulting in lamellipodia formation in podocytes in vitro in a phosphatidylinositol-3 kinase, focal adhesion kinase, Cas, and Crk1/2-dependent fashion. In mice, podocyte-specific deletion of Crk1/2 prevents or attenuates foot process effacement in two models of podocyte injury. This suggests that cellular mechanisms governing lamellipodial protrusion in vitro are similar to those in vivo during foot process effacement. Since Crk1/2 null mice develop and aged normally, we tested whether the Crk1/2 paralog, CrkL, functionally complements Crk1/2 in a podocyte-specific context. Podocyte-specific CrkL null mice, like podocyte-specific Crk1/2 null mice, developed and aged normally but were protected from protamine sulfate-induced foot process effacement. Simultaneous podocyte-specific deletion of Crk1/2 and CrkL resulted in albuminuria detected by six weeks post-partum and associated with altered podocyte process architecture. Nephrin-induced lamellipodia formation in podocytes in vitro was CrkL-dependent. CrkL formed a heterooligomer with Crk2 and, like Crk2, was recruited to tyrosine phosphorylated Nephrin. Thus, Crk1/2 and CrkL are physically-linked, functionally complement each other during podocyte foot process spreading, and together are required for developing typical foot process architecture. PMID:24499776

Genome-Wide Gene Expression Analysis Shows AKAP13-Mediated PKD1 Signaling Regulates the Transcriptional Response to Cardiac Hypertrophy.

PubMed

Johnson, Keven R; Nicodemus-Johnson, Jessie; Spindler, Mathew J; Carnegie, Graeme K

2015-01-01

In the heart, scaffolding proteins such as A-Kinase Anchoring Proteins (AKAPs) play a crucial role in normal cellular function by serving as a signaling hub for multiple protein kinases including protein kinase D1 (PKD1). Under cardiac hypertrophic conditions AKAP13 anchored PKD1 activates the transcription factor MEF2 leading to subsequent fetal gene activation and hypertrophic response. We used an expression microarray to identify the global transcriptional response in the hearts of wild-type mice expressing the native form of AKAP13 compared to a gene-trap mouse model expressing a truncated form of AKAP13 that is unable to bind PKD1 (AKAP13-ΔPKD1). Microarray analysis showed that AKAP13-ΔPKD1 mice broadly failed to exhibit the transcriptional profile normally associated with compensatory cardiac hypertrophy following trans-aortic constriction (TAC). The identified differentially expressed genes in WT and AKAP13-ΔPKD1 hearts are vital for the compensatory hypertrophic response to pressure-overload and include myofilament, apoptotic, and cell growth/differentiation genes in addition to genes not previously identified as affected by AKAP13-anchored PKD1. Our results show that AKAP13-PKD1 signaling is critical for transcriptional regulation of key contractile, cell death, and metabolic pathways during the development of compensatory hypertrophy in vivo.

Genome-Wide Gene Expression Analysis Shows AKAP13-Mediated PKD1 Signaling Regulates the Transcriptional Response to Cardiac Hypertrophy

PubMed Central

Johnson, Keven R.; Nicodemus-Johnson, Jessie; Spindler, Mathew J.

2015-01-01

In the heart, scaffolding proteins such as A-Kinase Anchoring Proteins (AKAPs) play a crucial role in normal cellular function by serving as a signaling hub for multiple protein kinases including protein kinase D1 (PKD1). Under cardiac hypertrophic conditions AKAP13 anchored PKD1 activates the transcription factor MEF2 leading to subsequent fetal gene activation and hypertrophic response. We used an expression microarray to identify the global transcriptional response in the hearts of wild-type mice expressing the native form of AKAP13 compared to a gene-trap mouse model expressing a truncated form of AKAP13 that is unable to bind PKD1 (AKAP13-ΔPKD1). Microarray analysis showed that AKAP13-ΔPKD1 mice broadly failed to exhibit the transcriptional profile normally associated with compensatory cardiac hypertrophy following trans-aortic constriction (TAC). The identified differentially expressed genes in WT and AKAP13-ΔPKD1 hearts are vital for the compensatory hypertrophic response to pressure-overload and include myofilament, apoptotic, and cell growth/differentiation genes in addition to genes not previously identified as affected by AKAP13-anchored PKD1. Our results show that AKAP13-PKD1 signaling is critical for transcriptional regulation of key contractile, cell death, and metabolic pathways during the development of compensatory hypertrophy in vivo. PMID:26192751

Neoplastic transformation of SV40-immortalized human urinary tract epithelial cells by in vitro exposure to 3-methylcholanthrene.

PubMed

Reznikoff, C A; Loretz, L J; Christian, B J; Wu, S Q; Meisner, L F

1988-08-01

Normal human urinary tract epithelial cells (HUC) were neoplastically transformed in vitro using a step-wise strategy. First, a partially transformed non-virus-producing cell line was obtained after infection of HUC with simian virus 40 (SV40). This cell line (SV-HUC-1) was demonstrated to be clonal in origin, as 100% of cells contained at least five of seven marker chromosomes. Marker chromosomes were formed by balanced translocations resulting in a 'pseudodiploid' cell line. SV-HUC-1 showed altered growth properties in vitro (e.g. anchorage independent growth) but failed to form tumors in athymic nude mice, even after 3 years in culture (80 passages). In the studies reported here, SV-HUC-1 at early passages (P15-P19) were exposed to 3-methylcholanthrene (MCA) in three separate experiments. After a six-week post-treatment period of cell culture, cells were inoculated s.c. into athymic nude mice. In all experiments, MCA-treated SV-HUC-1 formed carcinomas in mice usually with a latent period of 5-8 weeks. These carcinomas showed heterogeneity with respect to histopathologies and growth properties in the mice and karyotypes. All the tumors retained SV-HUC-1 chromosome markers, but each independent transformant was aneuploid and contained unique new marker chromosomes. Chromosomes usually altered in tumor cells included numbers 3, 5, 6, 9, 11 and 13. Mutations in the ras family of cellular proto-oncogenes resulting in altered mobility of the p21 protein product were not detected in six cell lines established from independently derived tumors. It is not yet known whether other cellular proto-oncogenes are activated in these tumorigenic transformants. Neither control SV-HUC-1 (which were not exposed to MCA), nor early passage HUC exposed to MCA formed tumors when inoculated into mice. Thus, the tumorigenic transformation of HUC resulted from the combined actions of SV40 and MCA.

The membrane mucin MUC4 is elevated in breast tumor lymph node metastases relative to matched primary tumors and confers aggressive properties to breast cancer cells.

PubMed

Workman, Heather C; Miller, Jamie K; Ingalla, Ellen Q; Kaur, Rouminder P; Yamamoto, Diane I; Beckett, Laurel A; Young, Lawrence Jt; Cardiff, Robert D; Borowsky, Alexander D; Carraway, Kermit L; Sweeney, Colleen; Carraway, Kermit L

2009-01-01

Previous studies indicate that overexpression of the membrane-associated mucin MUC4 is potently anti-adhesive to cultured tumor cells, and suppresses cellular apoptotic response to a variety of insults. Such observations raise the possibility that MUC4 expression could contribute to tumor progression or metastasis, but the potential involvement of MUC4 in breast cancer has not been rigorously assessed. The present study aimed to investigate the expression of the membrane mucin MUC4 in normal breast tissue, primary breast tumors and lymph node metastases, and to evaluate the role of MUC4 in promoting the malignant properties of breast tumor cells. MUC4 expression levels in patient-matched normal and tumor breast tissue was initially examined by immunoblotting lysates of fresh frozen tissue samples with a highly specific preparation of anti-MUC4 monoclonal antibody 1G8. Immunohistochemical analysis was then carried out using tissue microarrays encompassing patient-matched normal breast tissue and primary tumors, and patient-matched lymph node metastases and primary tumors. Finally, shRNA-mediated knockdown was employed to assess the contribution of MUC4 to the cellular growth and malignancy properties of JIMT-1 breast cancer cells. Immunoblotting and immunohistochemistry revealed that MUC4 levels are suppressed in the majority (58%, p < 0.001) of primary tumors relative to patient-matched normal tissue. On the other hand, lymph node metastatic lesions from 37% (p < 0.05) of patients expressed higher MUC4 protein levels than patient-matched primary tumors. MUC4-positive tumor emboli were often found in lymphovascular spaces of lymph node metastatic lesions. shRNA-mediated MUC4 knockdown compromised the migration, proliferation and anoikis resistance of JIMT-1 cells, strongly suggesting that MUC4 expression actively contributes to cellular properties associated with breast tumor metastasis. Our observations suggest that after an initial loss of MUC4 levels during the transition of normal breast tissue to primary tumor, the re-establishment of elevated MUC4 levels confers an advantage to metastasizing breast tumor cells by promoting the acquisition of cellular properties associated with malignancy.

Removal of cellular debris formed in the Disse space in patients with cholestasis.

PubMed

Dubuisson, L; Bioulac-Sage, P; Boussarie, L; Quinton, A; Saric, J; de Mascarel, A; Balabaud, C

1987-01-01

Using electron microscopy, we investigated how cellular debris, formed in the Disse space during cholestasis, was cleared. Ten patients with cholestasis of varied origin and severity were studied and compared with 10 controls without liver disease. In cholestatic patients, sinusoidal cells contained variable amounts of amylase PAS-positive material. In clean perfusion-fixed sinusoids the endothelial cells often appeared swollen and active, with few fenestrations. Hepatocyte blebs and cellular debris were sometimes seen in the Disse space. Two mechanisms were apparently involved in the clearing process: phagocytosis by macrophages either infiltrated into the Disse space, or forming the barrier; and the passage of debris from the Disse space into the sinusoidal lumen through the endothelial wall. Debris was either forced through enlarged pores or through the wall, with a progressive invagination followed by an outpouching in the lumen. The force, possibly provided by endothelial massage, may not be sufficient to push out cellular debris from the Disse space; morphological data seemed to indicate that endothelial damage may be a necessary factor. Debris present in the lumen was phagocytized by numerous active macrophages. Cellular debris was not observed in the Disse space of control patients.

Matrix Stiffness Corresponding to Strictured Bowel Induces a Fibrogenic Response in Human Colonic Fibroblasts

PubMed Central

Johnson, Laura A.; Rodansky, Eva S.; Sauder, Kay L.; Horowitz, Jeffrey C.; Mih, Justin D.; Tschumperlin, Daniel J.; Higgins, Peter D.

2013-01-01

Background Crohn’s disease is characterized by repeated cycles of inflammation and mucosal healing which ultimately progress to intestinal fibrosis. This inexorable progression towards fibrosis suggests that fibrosis becomes inflammation-independent and auto-propagative. We hypothesized that matrix stiffness regulates this auto-propagation of intestinal fibrosis. Methods The stiffness of fresh ex vivo samples from normal human small intestine, Crohn’s disease strictures, and the unaffected margin were measured with a microelastometer. Normal human colonic fibroblasts were cultured on physiologically normal or pathologically stiff matrices corresponding to the physiological stiffness of normal or fibrotic bowel. Cellular response was assayed for changes in cell morphology, α-smooth muscle actin (αSMA) staining, and gene expression. Results Microelastometer measurements revealed a significant increase in colonic tissue stiffness between normal human colon and Crohn’s strictures as well as between the stricture and adjacent tissue margin. In Ccd-18co cells grown on stiff matrices corresponding to Crohn’s strictures, cellular proliferation increased. Pathologic stiffness induced a marked change in cell morphology and increased αSMA protein expression. Growth on a stiff matrix induced fibrogenic gene expression, decreased matrix metalloproteinase and pro-inflammatory gene expression, and was associated with nuclear localization of the transcriptional cofactor MRTF-A. Conclusions Matrix stiffness, representative of the pathological stiffness of Crohn’s strictures, activates human colonic fibroblasts to a fibrogenic phenotype. Matrix stiffness affects multiple pathways suggesting the mechanical properties of the cellular environment are critical to fibroblast function and may contribute to autopropagation of intestinal fibrosis in the absence of inflammation, thereby contributing to the intractable intestinal fibrosis characteristic of Crohn’s disease. PMID:23502354

Cellular Composition of the Spleen and Changes in Splenic Lysosomes in the Dynamics of Dyslipidemia in Mice Caused by Repeated Administration of Poloxamer 407.

PubMed

Goncharova, N V; Shurlygina, A V; Mel'nikova, E V; Karmatskikh, O L; Avrorov, P A; Loktev, K V; Korolenko, T A

2015-11-01

We studied the effect of dyslipidemia induced by poloxamer 407 (300 mg/kg twice a week for 30 days) on cellular composition of the spleen and splenocyte lysosomes in mice. Changes in blood lipid profile included elevated concentrations of total cholesterol, aterogenic LDL, and triglycerides most pronounced in 24 h after the last poloxamer 407 injection; gradual normalization of lipid profile was observed in 4 days (except triglycerides) and 10 days. The most pronounced changes in the spleen (increase in organ weight and number of cells, inhibition in apoptosis, and reduced accumulation of vital dye acridine orange in lysosomes) were detected on day 4; on day 10, the indices returned to normal. Cathepsin D activity in the spleen also increased at these terms. The relationship between changes in the cellular composition of the spleen and dynamics of serum lipid profile in mice in dyslipidemia caused by repeated administrations of relatively low doses of poloxamer 407 is discussed.

Condition monitoring of 3G cellular networks through competitive neural models.

PubMed

Barreto, Guilherme A; Mota, João C M; Souza, Luis G M; Frota, Rewbenio A; Aguayo, Leonardo

2005-09-01

We develop an unsupervised approach to condition monitoring of cellular networks using competitive neural algorithms. Training is carried out with state vectors representing the normal functioning of a simulated CDMA2000 network. Once training is completed, global and local normality profiles (NPs) are built from the distribution of quantization errors of the training state vectors and their components, respectively. The global NP is used to evaluate the overall condition of the cellular system. If abnormal behavior is detected, local NPs are used in a component-wise fashion to find abnormal state variables. Anomaly detection tests are performed via percentile-based confidence intervals computed over the global and local NPs. We compared the performance of four competitive algorithms [winner-take-all (WTA), frequency-sensitive competitive learning (FSCL), self-organizing map (SOM), and neural-gas algorithm (NGA)] and the results suggest that the joint use of global and local NPs is more efficient and more robust than current single-threshold methods.

Cold atmospheric plasma jet-generated RONS and their selective effects on normal and carcinoma cells

PubMed Central

Kim, Sun Ja; Chung, T. H.

2016-01-01

Cold atmospheric helium plasma jets were fabricated and utilized for plasma–cell interactions. The effect of operating parameters and jet design on the generation of specific reactive oxygen and nitrogen species (RONS) within cells and cellular response were investigated. It was found that plasma treatment induced the overproduction of RONS in various cancer cell lines selectively. The plasma under a relatively low applied voltage induced the detachment of cells, a reduction in cell viability, and apoptosis, while the plasma under higher applied voltage led to cellular necrosis in our case. To determine whether plasma-induced reactive oxygen species (ROS) generation occurs through interfering with mitochondria-related cellular response, we examined the plasma effects on ROS generation in both parental A549 cells and A549 ρ0 cells. It was observed that cancer cells were more susceptible to plasma-induced RONS (especially nitric oxide (NO) and nitrogen dioxide (NO2−) radicals) than normal cells, and consequently, plasma induced apoptotic cell responses mainly in cancer cells. PMID:26838306

In vivo modulation of foreign body response on polyurethane by surface entrapment technique.

PubMed

Khandwekar, Anand P; Patil, Deepak P; Hardikar, Anand A; Shouche, Yogesh S; Doble, Mukesh

2010-11-01

Implanted polymeric materials, such as medical devices, provoke the body to initiate an inflammatory reaction, known as the foreign body response (FBR), which causes several complications. In this study, polyurethane (Tecoflex®, PU) surface modified with the nonionic surfactant Tween80® (PU/T80) and the cell adhesive PLL-RGD peptide (PU/PLL-RGD) by a previously described entrapment technique were implanted in the peritoneal cavity of Wistar rats for 30 days. Implants were retrieved and examined for tissue reactivity and cellular adherence by various microscopic and analytical techniques. Surface-induced inflammatory response was assessed by real-time PCR based quantification of proinflammatory cytokine transcripts, namely, TNF-α and IL-1β, normalized to housekeeping gene GAPDH. Cellular adherence and their distribution profile were assessed by microscopic examination of H&E stained implant sections. It was observed that PU/PLL-RGD followed by the bare PU surface exhibited severe inflammatory and fibrotic response with an average mean thickness of 19 and 12 μm, respectively, in 30 days. In contrast, PU/T80 surface showed only a cellular monolayer of 2-3 μm in thickness, with a mild inflammatory response and no fibrotic encapsulation. The PU/PLL-RGD peptide-modified substrate promoted an enhanced rate of macrophage cell fusion to form foreign body giant cell (FBGCs), whereas FBGCs were rarely observed on Tween80®-modified substrate. The expression levels of proinflammatory cytokines (TNF-α and IL-1β) were upregulated on PU/PLL-RGD surface followed by bare PU, whereas the cytokine expressions were significantly suppressed on PU/T80 surface. Thus, our study highlights modulation of foreign body response on polyurethane surfaces through surface entrapment technique in the form of differential responses observed on PLL-RGD and Tween80® modified surfaces with the former effective in triggering tissue cell adhesion thereby fibrous encapsulation, while the later being mostly resistant to this phenomenon.

Self-organization is a dynamic and lineage-intrinsic property of mammary epithelial cells

PubMed Central

Chanson, Lea; Brownfield, Douglas; Garbe, James C.; Kuhn, Irene; Stampfer, Martha R.; Bissell, Mina J.; LaBarge, Mark A.

2011-01-01

Loss of organization is a principle feature of cancers; therefore it is important to understand how normal adult multilineage tissues, such as bilayered secretory epithelia, establish and maintain their architectures. The self-organization process that drives heterogeneous mixtures of cells to form organized tissues is well studied in embryology and with mammalian cell lines that were abnormal or engineered. Here we used a micropatterning approach that confined cells to a cylindrical geometry combined with an algorithm to quantify changes of cellular distribution over time to measure the ability of different cell types to self-organize relative to each other. Using normal human mammary epithelial cells enriched into pools of the two principal lineages, luminal and myoepithelial cells, we demonstrated that bilayered organization in mammary epithelium was driven mainly by lineage-specific differential E-cadherin expression, but that P-cadherin contributed specifically to organization of the myoepithelial layer. Disruption of the actomyosin network or of adherens junction proteins resulted in either prevention of bilayer formation or loss of preformed bilayers, consistent with continual sampling of the local microenvironment by cadherins. Together these data show that self-organization is an innate and reversible property of communities of normal adult human mammary epithelial cells. PMID:21300877

Self-organization is a dynamic and lineage-intrinsic property of mammary epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chanson, L.; Brownfield, D.; Garbe, J. C.

Loss of organization is a principle feature of cancers; therefore it is important to understand how normal adult multilineage tissues, such as bilayered secretory epithelia, establish and maintain their architectures. The self-organization process that drives heterogeneous mixtures of cells to form organized tissues is well studied in embryology and with mammalian cell lines that were abnormal or engineered. Here we used a micropatterning approach that confined cells to a cylindrical geometry combined with an algorithm to quantify changes of cellular distribution over time to measure the ability of different cell types to self-organize relative to each other. Using normal humanmore » mammary epithelial cells enriched into pools of the two principal lineages, luminal and myoepithelial cells, we demonstrated that bilayered organization in mammary epithelium was driven mainly by lineage-specific differential E-cadherin expression, but that P-cadherin contributed specifically to organization of the myoepithelial layer. Disruption of the actomyosin network or of adherens junction proteins resulted in either prevention of bilayer formation or loss of preformed bilayers, consistent with continual sampling of the local microenvironment by cadherins. Together these data show that self-organization is an innate and reversible property of communities of normal adult human mammary epithelial cells.« less

NADPH oxidases of the brain: distribution, regulation, and function.

PubMed

Infanger, David W; Sharma, Ram V; Davisson, Robin L

2006-01-01

The NADPH oxidase is a multi-subunit enzyme that catalyzes the reduction of molecular oxygen to form superoxide (O(2)(-)). While classically linked to the respiratory burst in neutrophils, recent evidence now shows that O(2)(-) (and associated reactive oxygen species, ROS) generated by NADPH oxidase in nonphagocytic cells serves myriad functions in health and disease. An entire new family of NADPH Oxidase (Nox) homologues has emerged, which vary widely in cell and tissue distribution, as well as in function and regulation. A major concept in redox signaling is that while NADPH oxidase-derived ROS are necessary for normal cellular function, excessive oxidative stress can contribute to pathological disease. This certainly is true in the central nervous system (CNS), where normal NADPH oxidase function appears to be required for processes such as neuronal signaling, memory, and central cardiovascular homeostasis, but overproduction of ROS contributes to neurotoxicity, neurodegeneration, and cardiovascular diseases. Despite implications of NADPH oxidase in normal and pathological CNS processes, still relatively little is known about the mechanisms involved. This paper summarizes the evidence for NADPH oxidase distribution, regulation, and function in the CNS, emphasizing the diversity of Nox isoforms and their new and emerging role in neuro-cardiovascular function. In addition, perspectives for future research and novel therapeutic targets are offered.

Transcription Regulation of HYPK by Heat Shock Factor 1

PubMed Central

Das, Srijit; Bhattacharyya, Nitai Pada

2014-01-01

HYPK (Huntingtin Yeast Partner K) was originally identified by yeast two-hybrid assay as an interactor of Huntingtin, the protein mutated in Huntington's disease. HYPK was characterized earlier as an intrinsically unstructured protein having chaperone-like activity in vitro and in vivo. HYPK has the ability of reducing rate of aggregate formation and subsequent toxicity caused by mutant Huntingtin. Further investigation revealed that HYPK is involved in diverse cellular processes and required for normal functioning of cells. In this study we observed that hyperthermia increases HYPK expression in human and mouse cells in culture. Expression of exogenous Heat Shock Factor 1 (HSF1), upon heat treatment could induce HYPK expression, whereas HSF1 knockdown reduced endogenous as well as heat-induced HYPK expression. Putative HSF1-binding site present in the promoter of human HYPK gene was identified and validated by reporter assay. Chromatin immunoprecipitation revealed in vivo interaction of HSF1 and RNA polymerase II with HYPK promoter sequence. Additionally, acetylation of histone H4, a known epigenetic marker of inducible HSF1 binding, was observed in response to heat shock in HYPK gene promoter. Overexpression of HYPK inhibited cells from lethal heat-induced death whereas knockdown of HYPK made the cells susceptible to lethal heat shock-induced death. Apart from elevated temperature, HYPK was also upregulated by hypoxia and proteasome inhibition, two other forms of cellular stress. We concluded that chaperone-like protein HYPK is induced by cellular stress and under transcriptional regulation of HSF1. PMID:24465598

pH dependent transfer of nano-pores into membrane of cancer cells to induce apoptosis

NASA Astrophysics Data System (ADS)

Wijesinghe, Dayanjali; Arachchige, Mohan C. M.; Lu, Andrew; Reshetnyak, Yana K.; Andreev, Oleg A.

2013-12-01

Proper balance of ions in intracellular and extracellular space is the key for normal cell functioning. Changes in the conductance of membranes for ions will lead to cell death. One of the main differences between normal and cancerous cells is the low extracellular pHe and the reverse pH gradient: intracellular pHi is higher than extracellular pHe. We report here pH-selective transfer of nano-pores to cancer cells for the dis-regulation of balance of monovalent cations to induce cell death at mildly acidic pHe as it is in most solid tumors. Our approach is based on the pH-sensitive fusion of cellular membrane with the liposomes containing gramicidin A forming cation-conductive β-helix in the membrane. Fusion is promoted only at low extracellular pH by the pH (Low) Insertion Peptide (pHLIP®) attached to the liposomes. Gramicidin channels inserted into the cancer cells open flux of protons into the cytoplasm and disrupt balance of other monovalent cations, which induces cell apoptosis.

Microgravity

NASA Image and Video Library

2001-06-01

Cells cultured on Earth (left) typically settle quickly on the bottom of culture vessels due to gravity. In microgravity (right), cells remain suspended and aggregate to form three-dimensional tissue. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

What We Should Know Before Using Tissue Engineering Techniques to Repair Injured Tendons: A Developmental Biology Perspective

PubMed Central

Liu, Chia-Feng; Aschbacher-Smith, Lindsey; Barthelery, Nicolas J.; Dyment, Nathaniel; Butler, David

2011-01-01

Tendons connect muscles to bones, and serve as the transmitters of force that allow all the movements of the body. Tenocytes are the basic cellular units of tendons, and produce the collagens that form the hierarchical fiber system of the tendon. Tendon injuries are common, and difficult to repair, particularly in the case of the insertion of tendon into bone. Successful attempts at cell-based repair therapies will require an understanding of the normal development of tendon tissues, including their differentiated regions such as the fibrous mid-section and fibrocartilaginous insertion site. Many genes are known to be involved in the formation of tendon. However, their functional roles in tendon development have not been fully characterized. Tissue engineers have attempted to generate functional tendon tissue in vitro. However, a lack of knowledge of normal tendon development has hampered these efforts. Here we review studies focusing on the developmental mechanisms of tendon development, and discuss the potential applications of a molecular understanding of tendon development to the treatment of tendon injuries. PMID:21314435

Premature exhaustion of mesenchymal stromal cells from myelodysplastic syndrome patients.

PubMed

Pang, Yanbin; Deng, Chengxin; Geng, Suxia; Weng, Jianyu; Lai, Peilong; Liao, Pengjun; Zeng, Lingji; Lu, Zesheng; Zhang, Jing; Du, Xin

2017-01-01

Myelodysplastic syndrome (MDS) predominantly occurs in aging people. Over the past decades, the cellular and molecular pathologies of MDS cells have been intensively investigated. However, how the bone marrow stromal niches are altered during MDS development remains elusive. In this study, we attempted to isolate and characterize mesenchymal stromal cells (MSCs) from 30 MDS patients. We observed that only 9/30 bone marrow aspirations from MDS patients successfully formed a monolayer in vitro, while 17/17 bone marrow aspirations from normal donors (median age 45 years, range: 22-73 years) succeeded in this process. Compared to normal MSCs, the MDS MSCs showed premature exhaustion, including reduced osteogenic differentiation ability, slower passage rate, and extremely limited passage times. These functional defects were associated with downregulation of Osterix and Runx2 genes and increased cell cycle arrest and apoptosis. However, the premature exhaustion of MDS MSCs did not correlate with patients' ages, indicating that natural aging is not the cause of dysfunction in MDS MSCs. Our result provides a strong rational to target prematurely exhausting MSCs in future MDS treatment.

Bioreactor principles

NASA Technical Reports Server (NTRS)

2001-01-01

Cells cultured on Earth (left) typically settle quickly on the bottom of culture vessels due to gravity. In microgravity (right), cells remain suspended and aggregate to form three-dimensional tissue. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

Mesenchymal Stem and Progenitor Cells in Normal and Dysplastic Hematopoiesis—Masters of Survival and Clonality?

PubMed Central

Pleyer, Lisa; Valent, Peter; Greil, Richard

2016-01-01

Myelodysplastic syndromes (MDS) are malignant hematopoietic stem cell disorders that have the capacity to progress to acute myeloid leukemia (AML). Accumulating evidence suggests that the altered bone marrow (BM) microenvironment in general, and in particular the components of the stem cell niche, including mesenchymal stem cells (MSCs) and their progeny, play a pivotal role in the evolution and propagation of MDS. We here present an overview of the role of MSCs in the pathogenesis of MDS, with emphasis on cellular interactions in the BM microenvironment and related stem cell niche concepts. MSCs have potent immunomodulatory capacities and communicate with diverse immune cells, but also interact with various other cellular components of the microenvironment as well as with normal and leukemic stem and progenitor cells. Moreover, compared to normal MSCs, MSCs in MDS and AML often exhibit altered gene expression profiles, an aberrant phenotype, and abnormal functional properties. These alterations supposedly contribute to the “reprogramming” of the stem cell niche into a disease-permissive microenvironment where an altered immune system, abnormal stem cell niche interactions, and an impaired growth control lead to disease progression. The current article also reviews molecular targets that play a role in such cellular interactions and possibilities to interfere with abnormal stem cell niche interactions by using specific targeted drugs. PMID:27355944

The radiobiology of laser-driven particle beams: focus on sub-lethal responses of normal human cells

NASA Astrophysics Data System (ADS)

Manti, L.; Perozziello, F. M.; Borghesi, M.; Candiano, G.; Chaudhary, P.; Cirrone, G. A. P.; Doria, D.; Gwynne, D.; Leanza, R.; Prise, K. M.; Romagnani, L.; Romano, F.; Scuderi, V.; Tramontana, A.

2017-03-01

Accelerated proton beams have become increasingly common for treating cancer. The need for cost and size reduction of particle accelerating machines has led to the pioneering investigation of optical ion acceleration techniques based on laser-plasma interactions as a possible alternative. Laser-matter interaction can produce extremely pulsed particle bursts of ultra-high dose rates (>= 109 Gy/s), largely exceeding those currently used in conventional proton therapy. Since biological effects of ionizing radiation are strongly affected by the spatio-temporal distribution of DNA-damaging events, the unprecedented physical features of such beams may modify cellular and tissue radiosensitivity to unexplored extents. Hence, clinical applications of laser-generated particles need thorough assessment of their radiobiological effectiveness. To date, the majority of studies have either used rodent cell lines or have focussed on cancer cell killing being local tumour control the main objective of radiotherapy. Conversely, very little data exist on sub-lethal cellular effects, of relevance to normal tissue integrity and secondary cancers, such as premature cellular senescence. Here, we discuss ultra-high dose rate radiobiology and present preliminary data obtained in normal human cells following irradiation by laser-accelerated protons at the LULI PICO2000 facility at Laser Lab Europe, France.

Mechanisms of ozone toxicity in cultured cells. I. Reduced clonogenic ability of polyunsaturated fatty acid-supplemented fibroblasts. Effect of vitamin E

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konings, A.W.

1986-01-01

The direct action of ozone on viability and survival of normal and modified mouse lung fibroblasts has been studied. By cell manipulation of fibroblasts in culture, the content of polyunsaturated fatty acids (PUFA) in the phospholipids was increased from about 6% to about 40%. The cellular content of alpha-tocopherol (alpha-T) (vitamin E) could be drastically enhanced. Vitamin E supplementation to the cell did not influence the PUFA manipulation. Normal, PUFA, and PUFA(alpha-T) fibroblasts were exposed to ozone by bubbling 10 ppm through the cell suspensions for different periods of time (0-6 h). No significant effects of the ozone exposure couldmore » be established when normal fibroblasts were used. The PUFA fibroblasts, however, were very vulnerable to ozone toxicity, both in terms of dye uptake (Trypan blue) and cell death (clonogenic ability). When alpha-tocopherol was present in the cell (200 ng/10(6) cells), a clear protection against ozone toxicity was found. It is concluded that ozone toxicity might be higher under conditions of a relative high amount of polyunsaturated fatty acids in the membrane phospholipids of the cell and a low cellular antioxidant capacity. Cellular membranes are probably an important target for ozone-induced cell death.« less

Mesenchymal Stem and Progenitor Cells in Normal and Dysplastic Hematopoiesis-Masters of Survival and Clonality?

PubMed

Pleyer, Lisa; Valent, Peter; Greil, Richard

2016-06-27

Myelodysplastic syndromes (MDS) are malignant hematopoietic stem cell disorders that have the capacity to progress to acute myeloid leukemia (AML). Accumulating evidence suggests that the altered bone marrow (BM) microenvironment in general, and in particular the components of the stem cell niche, including mesenchymal stem cells (MSCs) and their progeny, play a pivotal role in the evolution and propagation of MDS. We here present an overview of the role of MSCs in the pathogenesis of MDS, with emphasis on cellular interactions in the BM microenvironment and related stem cell niche concepts. MSCs have potent immunomodulatory capacities and communicate with diverse immune cells, but also interact with various other cellular components of the microenvironment as well as with normal and leukemic stem and progenitor cells. Moreover, compared to normal MSCs, MSCs in MDS and AML often exhibit altered gene expression profiles, an aberrant phenotype, and abnormal functional properties. These alterations supposedly contribute to the "reprogramming" of the stem cell niche into a disease-permissive microenvironment where an altered immune system, abnormal stem cell niche interactions, and an impaired growth control lead to disease progression. The current article also reviews molecular targets that play a role in such cellular interactions and possibilities to interfere with abnormal stem cell niche interactions by using specific targeted drugs.

Failure of matrix metalloproteinase-9 dimer induction by phorbol 12-myristate 13-acetate in normal human cell lines.

PubMed

Waheed Roomi, Mohd; Kalinovsky, Tatiana; Rath, Matthias; Niedzwiecki, Aleksandra

2015-06-01

Increasing experimental and clinical data has identified an association between increased levels of matrix metalloproteinase (MMP)-9 and shortened patient survival, cancer progression and metastasis. MMP-9 has a significant role in tumor cell invasion and metastasis, as it digests the basement membrane and components of the extracellular matrix. MMP-9 is secreted in either a monomeric or dimeric form. Although limited evidence exists concerning MMP-9 dimers, certain studies have demonstrated that the dimer is associated with aggressive tumor progression. This is believed to be due to the fact that cellular migration depends upon the MMP-9 dimer, and not the monomer. Our previous study revealed that cancer cell MMP-9 dimer secretion patterns could be divided into different categories, and that high MMP-9 and MMP-9 dimer secretion levels were correlated with the most aggressive cancer cell lines. It has been established that signal transduction pathways and cytokines, including those activated by phorbol 12-myristate 13-acetate (PMA), regulate the expression of MMPs. The aim of the present study was to analyze the expression patterns of MMP-2, MMP-9 and MMP-9 dimer in normal human cells from a number of tissues treated with PMA. Muscle, epithelial and connective tissues were selected for use in the present study, since adenosarcomas, carcinomas and sarcomas are derived from these tissue types, respectively. The cell lines were first cultured in 24-well tissue culture plates containing recommended media that was supplemented with 10% fetal bovine serum and antibiotics. When at confluency, the cells were washed and fresh medium was added. In addition, a parallel set of cultures was treated with PMA. Subsequent to a 24-h incubation period, the media were collected and analyzed using gelatinase zymography for the expression of MMP-2 and MMP-9 monomer and dimer forms. The results revealed that the cellular expression of MMP-2 and MMP-9 was dependent upon the primary tissue subtype. All cell lines, regardless of tissue origin, expressed MMP-2. PMA induced the expression of MMP-9 in muscle tissue, glandular epithelia and supportive connective tissue cell lines. By contrast, cell lines of endothelial origin and proper connective tissue were insensitive to treatment with PMA. MMP-9 dimer secretion was not observed in any of the cell lines, which indicated that cellular migration is not supported by these cells.

Chemical-agnostic hazard prediction: statistical inference of in vitro toxicity pathways from proteomics responses to chemical mixtures

EPA Science Inventory

Toxicity pathways have been defined as normal cellular pathways that, when sufficiently perturbed as a consequence of chemical exposure, lead to an adverse outcome. If an exposure alters one or more normal biological pathways to an extent that leads to an adverse toxicity outcome...

Teaching the basics of cancer metabolism: Developing antitumor strategies by exploiting the differences between normal and cancer cell metabolism.

PubMed

Kalyanaraman, Balaraman

2017-08-01

This review of the basics of cancer metabolism focuses on exploiting the metabolic differences between normal and cancer cells. The first part of the review covers the different metabolic pathways utilized in normal cells to generate cellular energy, or ATP, and the glycolytic intermediates required to build the cellular machinery. The second part of the review discusses aerobic glycolysis, or the Warburg effect, and the metabolic reprogramming involving glycolysis, tricarboxylic acid cycle, and glutaminolysis in the context of developing targeted inhibitors in cancer cells. Finally, the selective targeting of cancer mitochondrial metabolism using positively charged lipophilic compounds as potential therapeutics and their ability to mitigate the toxic side effects of conventional chemotherapeutics in normal cells are discussed. I hope this graphical review will be useful in helping undergraduate, graduate, and medical students understand how investigating the basics of cancer cell metabolism could provide new insight in developing potentially new anticancer treatment strategies. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Transcriptome Analysis Reveals Markers of Aberrantly Activated Innate Immunity in Vitiligo Lesional and Non-Lesional Skin

PubMed Central

Huang, Yuanshen; Wang, Yang; Yu, Jie; Gao, Min; Levings, Megan; Wei, Shencai; Zhang, Shengquan; Xu, Aie; Su, Mingwan; Dutz, Jan; Zhang, Xuejun; Zhou, Youwen

2012-01-01

Background Vitiligo is characterized by the death of melanocytes in the skin. This is associated with the presence of T cell infiltrates in the lesional borders. However, at present, there is no detailed and systematic characterization on whether additional cellular or molecular changes are present inside vitiligo lesions. Further, it is unknown if the normal appearing non-lesional skin of vitiligo patients is in fact normal. The purpose of this study is to systematically characterize the molecular and cellular characteristics of the lesional and non-lesional skin of vitiligo patients. Methods and Materials Paired lesional and non-lesional skin biopsies from twenty-three vitiligo patients and normal skin biopsies from sixteen healthy volunteers were obtained with informed consent. The following aspects were analyzed: (1) transcriptome changes present in vitiligo skin using DNA microarrays and qRT-PCR; (2) abnormal cellular infiltrates in vitiligo skin explant cultures using flow cytometry; and (3) distribution of the abnormal cellular infiltrates in vitiligo skin using immunofluorescence microscopy. Results Compared with normal skin, vitiligo lesional skin contained 17 genes (mostly melanocyte-specific genes) whose expression was decreased or absent. In contrast, the relative expression of 13 genes was up-regulated. The up-regulated genes point to aberrant activity of the innate immune system, especially natural killer cells in vitiligo. Strikingly, the markers of heightened innate immune responses were also found to be up-regulated in the non-lesional skin of vitiligo patients. Conclusions and Clinical Implications As the first systematic transcriptome characterization of the skin in vitiligo patients, this study revealed previously unknown molecular markers that strongly suggest aberrant innate immune activation in the microenvironment of vitiligo skin. Since these changes involve both lesional and non-lesional skin, our results suggest that therapies targeting the entire skin surface may improve treatment outcomes. Finally, this study revealed novel mediators that may facilitate future development of vitiligo therapies. PMID:23251420

Innate Immune Activation in Obesity

PubMed Central

Lumeng, Carey N.

2014-01-01

The innate immune system is a prewired set of cellular and humoral components that has developed to sense perturbations in normal physiology and trigger responses to restore the system back to baseline. It is now understood that many of these components can also sense the physiologic changes that occur with obesity and be activated. While the exact reasons for this chronic immune response to obesity are unclear, there is strong evidence to suggest that innate inflammatory systems link obesity and disease. Based on this, anti-inflammatory therapies for diseases like type 2 diabetes and metabolic syndrome may form the core of future treatment plans. This review will highlight the components involved in the innate immune response and discuss the evidence that they contribute to the pathogenesis of obesity-associated diseases. PMID:23068074

The solid-state signaling pathway from extracellular matrix to nuclear matrix: The critical role of three-dimensional architecture for functional differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lelievre, S.; Bissell, M.J.

Breast cells are useful experimental subjects for cell biologists because the mammary gland is one of the few tissues that undergoes dramatic changes in form and function after adulthood. Recently, the study in our laboratory of a human breast tumor progression series has allowed for the analysis of changes in cellular architecture (including nuclear architecture) when phenotypically normal cells become tumorigenic. This research aims to participate in the battle against breast cancer by helping to understand tumor progression and to identify new therapeutic markers for cancer treatment. This article explores the advantages and challenges of using high resolution X-ray computedmore » microtomography for the study of 3-dimensional organization of breast tissue architecture.« less

Stress as a Normal Cue in the Symbiotic Environment.

PubMed

Schwartzman, Julia A; Ruby, Edward G

2016-05-01

All multicellular hosts form associations with groups of microorganisms. These microbial communities can be taxonomically diverse and dynamic, and their persistence is due to robust, and sometimes coevolved, host-microbe and microbe-microbe interactions. Chemical and physical sources of stress are prominently situated in this molecular exchange, as cues for cellular responses in symbiotic microbes. Stress in the symbiotic environment may arise from three sources: host tissues, microbe-induced immune responses, or other microbes in the host environment. The responses of microbes to these stresses can be general or highly specialized, and collectively may contribute to the stability of the symbiotic system. In this review, we highlight recent work that emphasizes the role of stress as a cue in the symbiotic environment of plants and animals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Putting tumours in context

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bissell, Mina J.; Radisky, Derek

2001-10-01

The interactions between cancer cells and their micro- and macroenvironment create a context that promotes tumor growth and protects it from immune attack. The functional association of cancer cells with their surrounding tissues forms a new 'organ' that changes as malignancy progresses. Investigation of this process might provide new insights into the mechanisms of tumorigenesis and could also lead to new therapeutic targets. Under normal conditions, ORGANS are made up of TISSUES that exchange information with other cell types via cell-cell contact, cytokines and the EXTRACELLULAR MATRIX (ECM). The ECM, which is produced by collaboration between STROMAL fibroblasts and EPITHELIALmore » cells, provides structural scaffolding for cells, as well as contextual information. The endothelial vasculature provides nutrients and oxygen, and cells of the immune system combat pathogens and remove apoptotic cells. Epithelial cells associate into intact, polarized sheets. These tissues communicate through a complex network of interactions: physically, through direct contact or through the intervening ECM, and biochemically, through both soluble and insoluble signalling molecules. In combination, these interactions provide the information that is necessary to maintain cellular differentiation and to create complex tissue structures. Occasionally, the intercellular signals that define the normal context become disrupted. Alterations in epithelial tissues can lead to movement of epithelial sheets and proliferation - for example, after activation of mesenchymal fibroblasts due to wounding.Normally, these conditions are temporary and reversible, but when inflammation is sustained, an escalating feedback loop ensues.Under persistent inflammatory conditions, continual upregulation of enzymes such as matrix metalloproteinases (MMPs) by stromal fibroblasts can disrupt the ECM, and invading immune cells can overproduce factors that promote abnormal proliferation. As this process progresses, the normal organization of the organ is replaced by a functional disorder. If there are pre-existing epithelial cells within this changing context that possess tumorigenic potential, they can start to proliferate. Alternatively, the abnormal interactions might lead to genomic instability within the epithelial cells and the acquisition of tumorigenic potential. The proliferating cancer cells can then interact with their microenvironment and enhance the abnormal interactions. At this point, the tumor has become its own organ, with a distinct context that now defines all its cellular responses. Here, we will examine how the mechanisms that contribute to the normal context also act to suppress developing tumors, how disruption of this context initiates and supports the process of tumorigenicity, and how some cells with a tumorigenic genotype can become phenotypically normal if the context is appropriately manipulated.« less

Simulation of root forms using cellular automata model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winarno, Nanang, E-mail: nanang-winarno@upi.edu; Prima, Eka Cahya; Afifah, Ratih Mega Ayu

This research aims to produce a simulation program for root forms using cellular automata model. Stephen Wolfram in his book entitled “A New Kind of Science” discusses the formation rules based on the statistical analysis. In accordance with Stephen Wolfram’s investigation, the research will develop a basic idea of computer program using Delphi 7 programming language. To best of our knowledge, there is no previous research developing a simulation describing root forms using the cellular automata model compared to the natural root form with the presence of stone addition as the disturbance. The result shows that (1) the simulation usedmore » four rules comparing results of the program towards the natural photographs and each rule had shown different root forms; (2) the stone disturbances prevent the root growth and the multiplication of root forms had been successfully modeled. Therefore, this research had added some stones, which have size of 120 cells placed randomly in the soil. Like in nature, stones cannot be penetrated by plant roots. The result showed that it is very likely to further develop the program of simulating root forms by 50 variations.« less

Subtotal Ablation of Parietal Epithelial Cells Induces Crescent Formation

PubMed Central

Sicking, Eva-Maria; Fuss, Astrid; Uhlig, Sandra; Jirak, Peggy; Dijkman, Henry; Wetzels, Jack; Engel, Daniel R.; Urzynicok, Torsten; Heidenreich, Stefan; Kriz, Wilhelm; Kurts, Christian; Ostendorf, Tammo; Floege, Jürgen; Smeets, Bart

2012-01-01

Parietal epithelial cells (PECs) of the renal glomerulus contribute to the formation of both cellular crescents in rapidly progressive GN and sclerotic lesions in FSGS. Subtotal transgenic ablation of podocytes induces FSGS but the effect of specific ablation of PECs is unknown. Here, we established an inducible transgenic mouse to allow subtotal ablation of PECs. Proteinuria developed during doxycycline-induced cellular ablation but fully reversed 26 days after termination of doxycycline administration. The ablation of PECs was focal, with only 30% of glomeruli exhibiting histologic changes; however, the number of PECs was reduced up to 90% within affected glomeruli. Ultrastructural analysis revealed disruption of PEC plasma membranes with cytoplasm shedding into Bowman’s space. Podocytes showed focal foot process effacement, which was the most likely cause for transient proteinuria. After >9 days of cellular ablation, the remaining PECs formed cellular extensions to cover the denuded Bowman’s capsule and expressed the activation marker CD44 de novo. The induced proliferation of PECs persisted throughout the observation period, resulting in the formation of typical cellular crescents with periglomerular infiltrate, albeit without accompanying proteinuria. In summary, subtotal ablation of PECs leads the remaining PECs to react with cellular activation and proliferation, which ultimately forms cellular crescents. PMID:22282596

Immune response

MedlinePlus

Innate immunity; Humoral immunity; Cellular immunity; Immunity; Inflammatory response; Acquired (adaptive) immunity ... normal and usually does not react against them. INNATE IMMUNITY Innate, or nonspecific, immunity is the defense ...

Normal forms for Hopf-Zero singularities with nonconservative nonlinear part

NASA Astrophysics Data System (ADS)

Gazor, Majid; Mokhtari, Fahimeh; Sanders, Jan A.

In this paper we are concerned with the simplest normal form computation of the systems x˙=2xf(x,y2+z2), y˙=z+yf(x,y2+z2), z˙=-y+zf(x,y2+z2), where f is a formal function with real coefficients and without any constant term. These are the classical normal forms of a larger family of systems with Hopf-Zero singularity. Indeed, these are defined such that this family would be a Lie subalgebra for the space of all classical normal form vector fields with Hopf-Zero singularity. The simplest normal forms and simplest orbital normal forms of this family with nonzero quadratic part are computed. We also obtain the simplest parametric normal form of any non-degenerate perturbation of this family within the Lie subalgebra. The symmetry group of the simplest normal forms is also discussed. This is a part of our results in decomposing the normal forms of Hopf-Zero singular systems into systems with a first integral and nonconservative systems.

Human Cortical Neural Stem Cells Expressing Insulin-Like Growth Factor-I: A Novel Cellular Therapy for Alzheimer’s Disease

PubMed Central

McGinley, Lisa M.; Sims, Erika; Lunn, J. Simon; Kashlan, Osama N.; Chen, Kevin S.; Bruno, Elizabeth S.; Pacut, Crystal M.; Hazel, Tom; Johe, Karl; Sakowski, Stacey A.

2016-01-01

Alzheimer’s disease (AD) is the most prevalent age-related neurodegenerative disorder and a leading cause of dementia. Current treatment fails to modify underlying disease pathologies and very little progress has been made to develop effective drug treatments. Cellular therapies impact disease by multiple mechanisms, providing increased efficacy compared with traditional single-target approaches. In amyotrophic lateral sclerosis, we have shown that transplanted spinal neural stem cells (NSCs) integrate into the spinal cord, form synapses with the host, improve inflammation, and reduce disease-associated pathologies. Our current goal is to develop a similar “best in class” cellular therapy for AD. Here, we characterize a novel human cortex-derived NSC line modified to express insulin-like growth factor-I (IGF-I), HK532-IGF-I. Because IGF-I promotes neurogenesis and synaptogenesis in vivo, this enhanced NSC line offers additional environmental enrichment, enhanced neuroprotection, and a multifaceted approach to treating complex AD pathologies. We show that autocrine IGF-I production does not impact the cell secretome or normal cellular functions, including proliferation, migration, or maintenance of progenitor status. However, HK532-IGF-I cells preferentially differentiate into gamma-aminobutyric acid-ergic neurons, a subtype dysregulated in AD; produce increased vascular endothelial growth factor levels; and display an increased neuroprotective capacity in vitro. We also demonstrate that HK532-IGF-I cells survive peri-hippocampal transplantation in a murine AD model and exhibit long-term persistence in targeted brain areas. In conclusion, we believe that harnessing the benefits of cellular and IGF-I therapies together will provide the optimal therapeutic benefit to patients, and our findings support further preclinical development of HK532-IGF-I cells into a disease-modifying intervention for AD. Significance There is no cure for Alzheimer’s disease (AD) and no means of prevention. Current drug treatments temporarily slow dementia symptoms but ultimately fail to alter disease course. Given the prevalence of AD and an increasingly aging population, alternative therapeutic strategies are necessary. Cellular therapies impact disease by multiple mechanisms, providing increased efficacy compared with traditional, single-target drug discovery approaches. This study describes a novel enhanced human stem cell line that produces increased amounts of growth factors beneficial to the disease environment. Findings support further development into a potentially safe and clinically translatable cellular therapy for patients with AD. PMID:26744412

Metal complexes of curcumin for cellular imaging, targeting, and photoinduced anticancer activity.

PubMed

Banerjee, Samya; Chakravarty, Akhil R

2015-07-21

Curcumin is a polyphenolic species. As an active ingredient of turmeric, it is well-known for its traditional medicinal properties. The therapeutic values include antioxidant, anti-inflammatory, antiseptic, and anticancer activity with the last being primarily due to inhibition of the transcription factor NF-κB besides affecting several biological pathways to arrest tumor growth and its progression. Curcumin with all these positive qualities has only remained a potential candidate for cancer treatment over the years without seeing any proper usage because of its hydrolytic instability involving the diketo moiety in a cellular medium and its poor bioavailability. The situation has changed considerably in recent years with the observation that curcumin in monoanionic form could be stabilized on binding to a metal ion. The reports from our group and other groups have shown that curcumin in the metal-bound form retains its therapeutic potential. This has opened up new avenues to develop curcumin-based metal complexes as anticancer agents. Zinc(II) complexes of curcumin are shown to be stable in a cellular medium. They display moderate cytotoxicity against prostate cancer and neuroblastoma cell lines. A similar stabilization and cytotoxic effect is reported for (arene)ruthenium(II) complexes of curcumin against a variety of cell lines. The half-sandwich 1,3,5-triaza-7-phosphatricyclo-[3.3.1.1]decane (RAPTA)-type ruthenium(II) complexes of curcumin are shown to be promising cytotoxic agents with low micromolar concentrations for a series of cancer cell lines. In a different approach, cobalt(III) complexes of curcumin are used for its cellular delivery in hypoxic tumor cells using intracellular agents that reduce the metal and release curcumin as a cytotoxin. Utilizing the photophysical and photochemical properties of the curcumin dye, we have designed and synthesized photoactive curcumin metal complexes that are used for cellular imaging by fluorescence microscopy and damaging the cancer cells on photoactivation in visible light while being minimally toxic in darkness. In this Account, we have made an attempt to review the current status of the chemistry of metal curcumin complexes and present results from our recent studies on curcumin complexes showing remarkable in vitro photocytotoxicity. The undesirable dark toxicity of the complexes can be reduced with suitable choice of the metal and the ancillary ligands in a ternary structure. The complexes can be directed to specific subcellular organelles. Selectivity by targeting cancer cells over normal cells can be achieved with suitable ligand design. We expect that this methodology is likely to provide an impetus toward developing curcumin-based photochemotherapeutics for anticancer treatment and cure.

The Effect of TIMP-1 on the Cone Mosaic in the Retina of the Rat Model of Retinitis Pigmentosa

PubMed Central

Ji, Yerina; Yu, Wan-Qing; Eom, Yun Sung; Bruce, Farouk; Craft, Cheryl Mae; Grzywacz, Norberto M.; Lee, Eun-Jin

2015-01-01

Purpose. The array of photoreceptors found in normal retinas provides uniform and regular sampling of the visual space. In contrast, cones in retinas of the S334ter-line-3 rat model for RP migrate to form a mosaic of rings, leaving large holes with few or no photoreceptors. Similar mosaics appear in human patients with other forms of retinal dystrophy. In the current study, we aimed to investigate the effect of tissue inhibitor of metalloproteinase-1 (TIMP-1) on the mosaic of cones in S334ter-line-3 rat retinas. We focused on TIMP-1 because it is one of the regulators of the extracellular matrix important for cellular migration. Methods. Immunohistochemistry was performed to reveal M-opsin cone cells (M-cone) and the results were quantified to test statistically whether or not TIMP-1 restores the mosaics to normal. In particular, the tests focused on the Voronoi and nearest-neighbor distance analyses. Results. Our tests indicated that TIMP-1 led to significant disruption of the M-opsin cone rings in S334ter-line-3 rat retinas and resulted in almost complete homogeneous mosaics. In addition, TIMP-1 induced the M-cone spatial distribution to become closer to random with decreased regularity in S334ter-line-3 rat retinas. Conclusions. These findings confirm that TIMP-1 induced M-cone mosaics in S334ter-line-3 to gain homogeneity without reaching the degree of regularity seen in normal retinal mosaics. Even if TIMP-1 fails to promote regularity, the effects of this drug on homogeneity appear to be so dramatic that TIMP-1 may be a potential therapeutic agent. TIMP-1 improves sampling of the visual field simply by causing homogeneity. PMID:25515575

[Some aspects of immune response in toxoplasmosis].

PubMed

Dziubek, Z; Zarnowska, H; Basiak, W; Górski, A; Kajfasz, P

2001-01-01

The study was performed to determine cell-mediated and humoral responses related to the clinical course of disease in adults with different forms of toxoplasmosis. The cellular response was estimated by blastogenic transformation of T-lymphocytes induced by OKT3 mitogenic stimulus, as well as by a specific soluble toxoplasmic antigen. The phenotype analysis of T-lymphocytes was performed using monoclonal antibody on FACS flow cytometer. The humoral response was examined by determining the levels of toxoplasma-specific IgA, IgM and IgG antibodies and total serum immunoglobulins. Significant disruption of the cell-mediated response was not observed (T-lymphocyte proliferation test). In the group of patients with lymphadenopathy, an increased proportion of CD8+ lymphocytes was only noted in the first month of the disease, although enlargement of the cervical lymph nodes was observed for up to a year. The individuals in question were found to have IgA antibodies against the p30 antigen of T. gondii, mainly in the period of disease up to 7 months. The proportion of CD4+ lymphocytes was sub-normal in all patients of this group who were studied in the first two months of the disease, and in most of those studied later. Three out of 14 patients with the ocular form of toxoplasmosis only had recent foci of inflammation in the retina, and were also found to have specific IgM. These patients had depressed CD4+ levels, and showed no reaction from CD8+ lymphocytes. Sub-normal CD4+ population could have been the cause of the weak stimulation of CD8+ cells and an expression of this is the long course of disease. Sub-normal CD4+ cells may be also results the suppressing effect of the parasite.

The nociception genes painless and Piezo are required for the cellular immune response of Drosophila larvae to wasp parasitization.

PubMed

Tokusumi, Yumiko; Tokusumi, Tsuyoshi; Schulz, Robert A

2017-05-13

In vertebrates, interaction between the nervous system and immune system is important to protect a challenged host from stress inputs from external sources. In this study, we demonstrate that sensory neurons are involved in the cellular immune response elicited by wasp infestation of Drosophila larvae. Multidendritic class IV neurons sense contacts from external stimuli and induce avoidance behaviors for host defense. Our findings show that inactivation of these sensory neurons impairs the cellular response against wasp parasitization. We also demonstrate that the nociception genes encoding the mechanosensory receptors Painless and Piezo, both expressed in class IV neurons, are essential for the normal cellular immune response to parasite challenge. Copyright © 2017. Published by Elsevier Inc.

Lempel-Ziv complexity analysis of one dimensional cellular automata.

PubMed

Estevez-Rams, E; Lora-Serrano, R; Nunes, C A J; Aragón-Fernández, B

2015-12-01

Lempel-Ziv complexity measure has been used to estimate the entropy density of a string. It is defined as the number of factors in a production factorization of a string. In this contribution, we show that its use can be extended, by using the normalized information distance, to study the spatiotemporal evolution of random initial configurations under cellular automata rules. In particular, the transfer information from time consecutive configurations is studied, as well as the sensitivity to perturbed initial conditions. The behavior of the cellular automata rules can be grouped in different classes, but no single grouping captures the whole nature of the involved rules. The analysis carried out is particularly appropriate for studying the computational processing capabilities of cellular automata rules.

Lempel-Ziv complexity analysis of one dimensional cellular automata

NASA Astrophysics Data System (ADS)

Estevez-Rams, E.; Lora-Serrano, R.; Nunes, C. A. J.; Aragón-Fernández, B.

2015-12-01

Lempel-Ziv complexity measure has been used to estimate the entropy density of a string. It is defined as the number of factors in a production factorization of a string. In this contribution, we show that its use can be extended, by using the normalized information distance, to study the spatiotemporal evolution of random initial configurations under cellular automata rules. In particular, the transfer information from time consecutive configurations is studied, as well as the sensitivity to perturbed initial conditions. The behavior of the cellular automata rules can be grouped in different classes, but no single grouping captures the whole nature of the involved rules. The analysis carried out is particularly appropriate for studying the computational processing capabilities of cellular automata rules.

Epithelial stem cells are formed by small-particles released from particle-producing cells

PubMed Central

Kong, Wuyi; Zhu, Xiao Ping; Han, Xiu Juan; Nuo, Mu; Wang, Hong

2017-01-01

Recent spatiotemporal report demonstrated that epidermal stem cells have equal potential to divide or differentiate, with no asymmetric cell division observed. Therefore, how epithelial stem cells maintain lifelong stem-cell support still needs to be elucidated. In mouse blood and bone marrow, we found a group of large cells stained strongly for eosin and containing coiled-tubing-like structures. Many were tightly attached to each other to form large cellular clumps. After sectioning, these large cell-clumps were composed of not cells but numerous small particles, however with few small “naked” nuclei. The small particles were about 2 to 3 μm in diameter and stained dense red for eosin, so they may be rich in proteins. Besides the clumps composed of small particles, we identified clumps formed by fusion of the small particles and clumps of newly formed nucleated cells. These observations suggest that these small particles further fused and underwent cellularization. E-cadherin was expressed in particle-fusion areas, some “naked” nuclei and the newly formed nucleated cells, which suggests that these particles can form epithelial cells via fusion and nuclear remodeling. In addition, we observed similar-particle fusion before epithelial cellularization in mouse kidney ducts after kidney ischemia, which suggests that these particles can be released in the blood and carried to the target tissues for epithelial-cell regeneration. Oct4 and E-cadherin expressed in the cytoplasmic areas in cells that were rich in protein and mainly located in the center of the cellular clumps, suggesting that these newly formed cells have become tissue-specific epithelial stem cells. Our data provide evidence that these large particle-producing cells are the origin of epithelial stem cells. The epithelial stem cells are newly formed by particle fusion. PMID:28253358

Ion Movements in Shock in Relation to Survival and Its Modifications

DTIC Science & Technology

1985-01-01

from normal to irreversibly injured are initiated and modified by primary and/or secondary effects of ion redistributions taking place between the...reactions to injury by the shock state has become possible. However, spcclflc aspects concerning effects at the cellular and subcellular levels need...to be further clarified. Therefore, the aim of this study was to characterize the cellular and subcellular effects of hemorrhagic and bacteremic shock

Developmental consequences of cryopreservation of mammalian oocytes and embryos.

PubMed

Smith, Gary D; Silva E Silva, Cristine Ane

2004-08-01

During the last three decades, significant advances have been made in successful cryopreservation of mammalian preimplantation embryos, and more recently oocytes. The ability to cryopreserve, thaw, and establish pregnancies with supernumerary preimplantation embryos has become an important tool in fertility treatment. Human oocyte cryopreservation has practical application in preserving fertility for individuals at risk of compromised egg quality due to cancer treatments or advanced maternal age. While oocyte/embryo cryopreservation success has increased over time, there is still room for improvement. Oocytes and embryos are susceptible to cryo-damage, which collectively entails cellular damage caused by mechanical, chemical, or thermal forces during the freeze-thaw process. Basic studies focused on understanding cellular structures, their composition, and more importantly their functions, in normal cell developments will continue to be critical in assessing, understanding, and correcting oocyte/embryo cryo-damage. This review will delineate many of the oocyte/embryo intracellular and extracellular structures that are or may be compromised during cryopreservation. A global theme presented throughout this review is that many structural components of the oocyte/embryo also have essential functional roles in development. Compromising these cellular structures, and thus their cellular homeostatic functions, can deleteriously influence initial cryo-survival or compromise subsequent normal development through effects on the oocyte and/or early embryo.

RGD/TAT-functionalized chitosan-graft-PEI-PEG gene nanovector for sustained delivery of NT-3 for potential application in neural regeneration.

PubMed

Wu, Dongni; Zhang, Yongnu; Xu, Xiaoting; Guo, Ting; Xie, Deming; Zhu, Rong; Chen, Shengfeng; Ramakrishna, Seeram; He, Liumin

2018-05-01

In this study, we prepared a multifunctional gene delivery nanovector containing a chitosan (CS) backbone and polyethylenimine (PEI) arms with arginine-glycine-aspartate (RGD)/twin-arginine translocation (TAT) conjugated via polyethylene glycol (PEG). Branched PEI, with a molecular weight of 2000 Da, was used to achieve a balance between biocompatibility and transfection efficiency, whereas RGD/TAT peptides were conjugated for enhanced targeting ability and cellular uptake. Synthesis of the copolymers was confirmed by characterizing the chemical structure with 1 H nuclear magnetic resonance and Fourier Transform Infrared Spectroscopy (FTIR). The nanovector was biocompatible with cells and showed excellent capability for DNA condensation; the resulting complexes with DNA were well-formed, and possessed small particle size and reasonable positive charge. Higher gene transfection efficiency, compared to that achieved with PEI (25 kDa), was confirmed in tumor (HeLa cells) and normal cells (293T and NIH 3T3 cells). More importantly, the cells transfected with the chitosan-graft-PEI-PEG/pCMV-EGFP-Ntf3 complex produced sustained neurotrophin-3 with a linear increase in cumulative concentration, which induced neuronal differentiation of neural stem cell and promoted neurite outgrowth. These findings suggested that our multifunctional copolymers might be ideal nanovectors for engineering cells via gene transfection, and could potentially be applied in tumor therapy and regenerative medicine. We successfully prepared a multifunctional gene delivery nanovector containing branched PEI with a molecular weight of 2000 Da to balance between biocompatibility and transfection efficiency, and RGD/TAT peptides for enhanced targeting ability and cellular uptake. The well-formed CPPP/DNA complexes of small particle size and reasonable positive charges potentially enhanced gene transfection in both tumor and normal cells. More importantly, the CPPP/pCMV-EGFP-Ntf3 complex-transfected 293T cells could produce sustained NT-3 with a constant ratio, which induced neuron differentiation of NSC and promoted neurite outgrowth. Therefore, our study provided an effective strategy for producing neurotrophins by engineering cells with gene delivery, which deserved wide investigation and potential application in regenerative medicine. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A Modified Protocol for the Isolation of Primary Human Hepatocytes with Improved Viability and Function from Normal and Diseased Human Liver.

PubMed

Bartlett, David C; Newsome, Philip N

2017-01-01

Successful hepatocyte isolation is critical for continued development of cellular transplantation. However, most tissue available for research is from diseased liver and the results of hepatocyte isolation from such tissue are inferior compared to normal tissue. Here we describe a modified method, combining the use of Liberase and N-acetylcysteine (NAC), for the isolation of primary human hepatocytes with high viability from normal and diseased liver.

Terminal addition in a cellular world.

PubMed

Torday, J S; Miller, William B

2018-07-01

Recent advances in our understanding of evolutionary development permit a reframed appraisal of Terminal Addition as a continuous historical process of cellular-environmental complementarity. Within this frame of reference, evolutionary terminal additions can be identified as environmental induction of episodic adjustments to cell-cell signaling patterns that yield the cellular-molecular pathways that lead to differing developmental forms. Phenotypes derive, thereby, through cellular mutualistic/competitive niche constructions in reciprocating responsiveness to environmental stresses and epigenetic impacts. In such terms, Terminal Addition flows according to a logic of cellular needs confronting environmental challenges over space-time. A reconciliation of evolutionary development and Terminal Addition can be achieved through a combined focus on cell-cell signaling, molecular phylogenies and a broader understanding of epigenetic phenomena among eukaryotic organisms. When understood in this manner, Terminal Addition has an important role in evolutionary development, and chronic disease might be considered as a form of 'reverse evolution' of the self-same processes. Copyright © 2017. Published by Elsevier Ltd.

Long-distance communication by specialized cellular projections during pigment pattern development and evolution

PubMed Central

Eom, Dae Seok; Bain, Emily J; Patterson, Larissa B; Grout, Megan E; Parichy, David M

2015-01-01

Changes in gene activity are essential for evolutionary diversification. Yet, elucidating the cellular behaviors that underlie modifications to adult form remains a profound challenge. We use neural crest-derived adult pigmentation of zebrafish and pearl danio to uncover cellular bases for alternative pattern states. We show that stripes in zebrafish require a novel class of thin, fast cellular projection to promote Delta-Notch signaling over long distances from cells of the xanthophore lineage to melanophores. Projections depended on microfilaments and microtubules, exhibited meandering trajectories, and stabilized on target cells to which they delivered membraneous vesicles. By contrast, the uniformly patterned pearl danio lacked such projections, concomitant with Colony stimulating factor 1-dependent changes in xanthophore differentiation that likely curtail signaling available to melanophores. Our study reveals a novel mechanism of cellular communication, roles for differentiation state heterogeneity in pigment cell interactions, and an unanticipated morphogenetic behavior contributing to a striking difference in adult form. DOI: http://dx.doi.org/10.7554/eLife.12401.001 PMID:26701906

Differential cellular responses by oncogenic levels of c-Myc expression in long-term confluent retinal pigment epithelial cells.

PubMed

Wang, Yiping; Cheng, Xiangdong; Samma, Muhammad Kaleem; Kung, Sam K P; Lee, Clement M; Chiu, Sung Kay

2018-06-01

c-Myc is a highly pleiotropic transcription factor known to control cell cycle progression, apoptosis, and cellular transformation. Normally, ectopic expression of c-Myc is associated with promoting cell proliferation or triggering cell death via activating p53. However, it is not clear how the levels of c-Myc lead to different cellular responses. Here, we generated a series of stable RPE cell clones expressing c-Myc at different levels, and found that consistent low level of c-Myc induced cellular senescence by activating AP4 in post-confluent RPE cells, while the cells underwent cell death at high level of c-Myc. In addition, high level of c-Myc could override the effect of AP4 on cellular senescence. Further knockdown of AP4 abrogated senescence-like phenotype in cells expressing low level of c-Myc, and accelerated cell death in cells with medium level of c-Myc, indicating that AP4 was required for cellular senescence induced by low level of c-Myc.

Aquatide Activation of SIRT1 Reduces Cellular Senescence through a SIRT1-FOXO1-Autophagy Axis.

PubMed

Lim, Chae Jin; Lee, Yong-Moon; Kang, Seung Goo; Lim, Hyung W; Shin, Kyong-Oh; Jeong, Se Kyoo; Huh, Yang Hoon; Choi, Suin; Kor, Myungho; Seo, Ho Seong; Park, Byeong Deog; Park, Keedon; Ahn, Jeong Keun; Uchida, Yoshikazu; Park, Kyungho

2017-09-01

Ultraviolet (UV) irradiation is a relevant environment factor to induce cellular senescence and photoaging. Both autophagy- and silent information regulator T1 (SIRT1)-dependent pathways are critical cellular processes of not only maintaining normal cellular functions, but also protecting cellular senescence in skin exposed to UV irradiation. In the present studies, we investigated whether modulation of autophagy induction using a novel synthetic SIRT1 activator, heptasodium hexacarboxymethyl dipeptide-12 (named as Aquatide), suppresses the UVB irradiation-induced skin aging. Treatment with Aquatide directly activates SIRT1 and stimulates autophagy induction in cultured human dermal fibroblasts. Next, we found that Aquatide-mediated activation of SIRT1 increases autophagy induction via deacetylation of forkhead box class O (FOXO) 1. Finally, UVB irradiation-induced cellular senescence measured by SA-β-gal staining was significantly decreased in cells treated with Aquatide in parallel to occurring SIRT1 activation-dependent autophagy. Together, Aquatide modulates autophagy through SIRT1 activation, contributing to suppression of skin aging caused by UV irradiation.

Segmented ceramic liner for induction furnaces

DOEpatents

Gorin, Andrew H.; Holcombe, Cressie E.

1994-01-01

A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace.

Segmented ceramic liner for induction furnaces

DOEpatents

Gorin, A.H.; Holcombe, C.E.

1994-07-26

A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace. 5 figs.

Differential Expression of c-fos Proto-Oncogene in Normal Oral Mucosa versus Squamous Cell Carcinoma

PubMed Central

Krishna, Akhilesh; Bhatt, Madan Lal Brahma; Singh, Vineeta; Singh, Shraddha; Gangwar, Pravin Kumar; Singh, Uma Shankar; Kumar, Vijay; Mehrotra, Divya

2018-01-01

Background: The c-Fos nuclear protein dimerizes with Jun family proteins to form the transcription factor AP-1 complex which participates in signal transduction and regulation of normal cellular processes. In tumorigenesis, c-Fos promotes invasive growth through down-regulation of tumor suppressor genes but its role in oral carcinogenesis is not clear. Objectives: This study concerned c-fos gene expression in normal and malignant tissues of the oral cavity, with attention to associations between expression status and clinico-pathological profiles of OSCC patients. Method: A total of 65 histopathologically confirmed OSCC tissue samples were included in case group along with an equal number of age and sex-matched normal tissue samples of oral cavity for the control group. c-Fos protein and m-RNA expressions were analyzed using immunohistochemistry and qRT-PCR, respectively. Results: A significant low expression of c-Fos protein was observed in OSCC cases than normal control subjects (p= <0.001). The mean percent positivity of c-Fos protein in cases vs. controls was 24.91± 2.7 vs. 49.68± 2.2 (p= <0.001). Most OSCC tissue samples showed weak or moderate c-Fos expression whereas 53.8% of normal tissue sections presented with strong immunostaining. Moreover, the relative m-RNA expression for the c-fos gene was significantly decreased in case group (0.93± 0.48) as compared to the control group (1.22± 0.87). Majority of c-Fos positive cases were diagnosed with well developed tumor. The mean percent positivity of c-Fos protein was significantly lower in higher grade tumor as compared with normal oral mucosa (p= < 0.001). Conclusion: The present study suggested that the c-fos gene is downregulated in oral carcinomas. The disparity of c-Fos protein levels in different pathological grades of tumor and normal oral tissue samples may indicate that loss of c-Fos expression is related with the progression of OSCC. PMID:29582647

Stem Cells and Scaffolds for Vascularizing Engineered Tissue Constructs

NASA Astrophysics Data System (ADS)

Luong, E.; Gerecht, S.

The clinical impact of tissue engineering depends upon our ability to direct cells to form tissues with characteristic structural and mechanical properties from the molecular level up to organized tissue. Induction and creation of functional vascular networks has been one of the main goals of tissue engineering either in vitro, for the transplantation of prevascularized constructs, or in vivo, for cellular organization within the implantation site. In most cases, tissue engineering attempts to recapitulate certain aspects of normal development in order to stimulate cell differentiation and functional tissue assembly. The induction of tissue growth generally involves the use of biodegradable and bioactive materials designed, ideally, to provide a mechanical, physical, and biochemical template for tissue regeneration. Human embryonic stem cells (hESCs), derived from the inner cell mass of a developing blastocyst, are capable of differentiating into all cell types of the body. Specifically, hESCs have the capability to differentiate and form blood vessels de novo in a process called vasculogenesis. Human ESC-derived endothelial progenitor cells (EPCs) and endothelial cells have substantial potential for microvessel formation, in vitro and in vivo. Human adult EPCs are being isolated to understand the fundamental biology of how these cells are regulated as a population and to explore whether these cells can be differentiated and reimplanted as a cellular therapy in order to arrest or even reverse damaged vasculature. This chapter focuses on advances made toward the generation and engineering of functional vascular tissue, focusing on both the scaffolds - the synthetic and biopolymer materials - and the cell sources - hESCs and hEPCs.

New agents and approaches to treatment in Niemann-Pick type C disease.

PubMed

Pérez-Poyato, María S; Pineda, Mercé

2011-06-01

Niemann-Pick disease type C is an autosomal recessive disorder caused by mutations in either one of the two genes, NPC1 or NPC2, which encode proteins involved in the regulation of normal transport and/or processing of free cholesterol. Several types of lipids including free cholesterol (unesterified), sphingosine, sphingomyelin, phospholipids and glycosphingolipids (glucosylceramide and gangliosides GM2 and GM3) are accumulated in lysosomes and late endosomes of cells, with pronounced concentrations in the liver and the spleen. The key laboratory diagnostic test for NP-C is filliping staining of cultured skin fibroblasts from the patient, to demonstrate free cholesterol accumulation in lysosomes secondary to impaired intracellular cholesterol transport. The symptomatology and rate of disease progression are strongly influenced by age at disease onset and different clinical forms have been described on this basis: Perinatal, Early-infantile (EI), late-infantile (LI), juvenile and adult forms. Clinical symptoms include progressive neurological deterioration and visceral organomegaly. Nowadays there is no fully effective treatment, only supportive measures for relief of specific manifestations of the disease. The intervention to slow disease progression is the most promising therapy. A number of experimental disease - specific therapies, based on the molecular pathology of NP-C, have been tested in cell culture and animal models including neurosteroids, cholesterol - binding agents, curcumin and Miglustat. This paper summarizes the recent developments that have been investigated for the treatment in patients and animal models with NPC. Current therapeutic approaches have been classified based on the targeting of cellular function, the anti - apoptotic cellular mechanisms and the stem cells therapy.

The Ethylene Responsive Factor Required for Nodulation 1 (ERN1) Transcription Factor Is Required for Infection-Thread Formation in Lotus japonicus.

PubMed

Kawaharada, Yasuyuki; James, Euan K; Kelly, Simon; Sandal, Niels; Stougaard, Jens

2017-03-01

Several hundred genes are transcriptionally regulated during infection-thread formation and development of nitrogen-fixing root nodules. We have characterized a set of Lotus japonicus mutants impaired in root-nodule formation and found that the causative gene, Ern1, encodes a protein with a characteristic APETALA2/Ethylene Responsive Factor (AP2/ERF) transcription-factor domain. Phenotypic characterization of four ern1 alleles shows that infection pockets are formed but root-hair infection threads are absent. Formation of root-nodule primordia is delayed and no normal transcellular infection threads are found in the infected nodules. Corroborating the role of ERN1 (ERF Required for Nodulation1) in nodule organogenesis, spontaneous nodulation induced by an autoactive CCaMK and cytokinin-induced nodule primordia were not observed in ern1 mutants. Expression of Ern1 is induced in the susceptible zone by Nod factor treatment or rhizobial inoculation. At the cellular level, the pErn1:GUS reporter is highly expressed in root epidermal cells of the susceptible zone and in the cortical cells that form nodule primordia. The genetic regulation of this cellular expression pattern was further investigated in symbiotic mutants. Nod factor induction of Ern1 in epidermal cells was found to depend on Nfr1, Cyclops, and Nsp2 but was independent of Nin and Nf-ya1. These results suggest that ERN1 functions as a transcriptional regulator involved in the formation of infection threads and development of nodule primordia and may coordinate these two processes.

Neuroglobin and prion cellular localization: investigation of a potential interaction.

PubMed

Lechauve, Christophe; Rezaei, Human; Celier, Chantal; Kiger, Laurent; Corral-Debrinski, Marisol; Noinville, Sylvie; Chauvierre, Cédric; Hamdane, Djemel; Pato, Christine; Marden, Michael C

2009-05-22

Neuroglobin (Ngb) and the cellular prion protein (PrP(c)), proteins of unknown function in the nervous system, are known to be expressed in the retina and have been observed in different rat retinal cells. The retina is the site of the highest concentration for Ngb, a heme protein of similar size and conformation to myoglobin. In this study, we demonstrated by immunohistochemical analysis of retinal colocalization of Ngb and PrP(c) in the ganglion cell layer. Considering for these two a common protective role in relation to oxidative stress and a possible transient contact during migration of PrP(c) through the eye or upon neuronal degradation, we undertook in vitro studies of the interaction of the purified proteins. Mixing these two proteins leads to rapid aggregation, even at submicromolar concentrations. As observed with the use of dynamic light scattering, particles comprising both proteins evolve to hundreds of nanometers within several seconds, a first report showing that PrP(c) is able to form aggregates without major structural changes. The main effect would then appear to be a protein-protein interaction specific to the surface charge of the Ngb protein with PrP(c) N-terminal sequence. A dominant parameter is the solvent ionic force, which can significantly modify the final state of aggregation. PrP(c), normally anchored to the cell membrane, is toxic in the cytoplasm, where Ngb is present; this could suggest an Ngb function of scavenging proteins capable of forming deleterious aggregates considering a charge complementarity in the complex.

GAPDH: the missing link between glycolysis and mitochondrial oxidative phosphorylation?

PubMed

Ramzan, Rabia; Weber, Petra; Linne, Uwe; Vogt, Sebastian

2013-10-01

The main function of glycolysis and oxidative phosphorylation is to produce cellular energy in the form of ATP. In the present paper we propose a link between both of these energy-regulatory processes in the form of GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and CytOx (cytochrome c oxidase). GAPDH is the sixth enzyme of glycolysis, whereas CytOx is the fourth complex of the mitochondrial oxidative phosphorylation system. In MS analysis, GAPDH was found to be associated with a BN-PAGE (blue native PAGE)-isolated complex of CytOx from bovine heart tissue homogenates. Both GAPDH and CytOx are highly regulated under normal energy metabolic conditions, but both of these enzymes are highly deregulated in the presence of oxidative stress. The interaction of GAPDH with CytOx could be the point of interest as it has already been shown that GAPDH protein damage results in a marked decrease in cellular ATP levels. On the other hand, decreasing the ATP/ADP ratio may ultimately result in switching off the allosteric ATP inhibition of CytOx leading to increased ROS (reactive oxygen species), cytochrome c release and apoptosis. Moreover, we have previously reported that allosteric ATP inhibition of CytOx is responsible for keeping the membrane potential at low healthy values, thus avoiding the production of ROS and this allosteric ATP inhibition is switched on at a high ATP/ADP ratio. So, in the present paper, we propose a scheme that could prove to be a link between these two enzymes and their role in the prevalence of diseases.

The endoplasmic reticulum stress response in aging and age-related diseases

PubMed Central

Brown, Marishka K.; Naidoo, Nirinjini

2012-01-01

The endoplasmic reticulum(ER) is a multifunctional organelle within which protein folding, lipid biosynthesis, and calcium storage occurs. Perturbations such as energy or nutrient depletion, disturbances in calcium or redox status that disrupt ER homeostasis lead to the misfolding of proteins, ER stress and up-regulation of several signaling pathways coordinately called the unfolded protein response (UPR). The UPR is characterized by the induction of chaperones, degradation of misfolded proteins and attenuation of protein translation. The UPR plays a fundamental role in the maintenance of cellular homeostasis and thus is central to normal physiology. However, sustained unresolved ER stress leads to apoptosis. Aging linked declines in expression and activity of key ER molecular chaperones and folding enzymes compromise proper protein folding and the adaptive response of the UPR. One mechanism to explain age associated declines in cellular functions and age-related diseases is a progressive failure of chaperoning systems. In many of these diseases, proteins or fragments of proteins convert from their normally soluble forms to insoluble fibrils or plaques that accumulate in a variety of organs including the liver, brain or spleen. This group of diseases, which typically occur late in life includes Alzheimer's, Parkinson's, type II diabetes and a host of less well known but often equally serious conditions such as fatal familial insomnia. The UPR is implicated in many of these neurodegenerative and familial protein folding diseases as well as several cancers and a host of inflammatory diseases including diabetes, atherosclerosis, inflammatory bowel disease and arthritis. This review will discuss age-related changes in the ER stress response and the role of the UPR in age-related diseases. PMID:22934019

ALPHA-FETOPROTEIN (AFP), STEM CELLS, AND CANCER: HOW STUDY OF THE PRODUCTION OF AFP DURING CHEMICAL HEPATOCARCINOGENESIS LED TO REAFFIRMATION OF THE STEM CELL THEORY OF CANCER

PubMed Central

Sell, Stewart

2008-01-01

Identification of the cells in the liver that produce alpha-fetoprotein (AFP) during development, in response to liver injury, and during the early stages of chemical hepatocarcinogenesis led to the conclusion that maturation arrest of liver-determined tissue stem cells was the cellular process that gives rise to hepatocellular carcinomas (HCC). When the cellular changes in these processes were compared that of the formation of teratocarcinomas, the hypothesis arose that all cancers arise from maturation arrest of tissue determined stem cells. This was essentially a reinterpretation of the embryonal rest theory of cancer whereby tissue stem cells take the role of embryonal rests. A corollary of the stem cell theory of the origin of cancer is that cancers contain the same functional cell populations as do normal tissues: stem cells, transit-amplifying cells, and mature cells. Cancer stem cells retain the essential feature of normal stem cells: the ability to self-renew. Growth of cancers is due to continued proliferation of cancer transit-amplifying cells that do not differentiate to mature cells (maturation arrest). On the other hand, cancer stem cells generally divide very rarely and contribute little to tumor growth. However, the presence of cancer stem cells in tumors is believed to be responsible for the properties of immortalization, transplantability and resistance to therapy characteristic of cancers. Current therapies for cancer (chemotherapy, radiotherapy, anti-angiogenesis and differentiation therapy) are directed against the cancer transit amplifying cells. When these therapies are discontinued, the cancer re-forms from the cancer stem cells. Therapy directed toward interruption of the cell-signaling pathways that maintain cancer stem cells could lead to new modalities to the prevention of re-growth of the cancer. PMID:18612221

Using organotypic (raft) epithelial tissue cultures for the biosynthesis and isolation of infectious human papillomaviruses.

PubMed

Ozbun, Michelle A; Patterson, Nicole A

2014-08-01

Papillomaviruses have a strict tropism for epithelial cells, and they are fully reliant on cellular differentiation for completion of their life cycles, resulting in the production of progeny virions. Thus, a permissive environment for full viral replication in vitro-wherein virion morphogenesis occurs under cooperative viral and cellular cues-requires the cultivation of epithelium. Presented in the first section of this unit is a protocol to grow differentiating epithelial tissues that mimic many important morphological and biochemical aspects of normal skin. The technique involves growing epidermal cells atop a dermal equivalent consisting of live fibroblasts and a collagen lattice. Epithelial stratification and differentiation ensues when the keratinocyte-dermal equivalent is placed at the air-liquid interface. The apparent floating nature of the cell-matrix in this method led to the nickname "raft" cultures. The general technique can be applied to normal low passage keratinocytes, to cells stably transfected with papillomavirus genes or genomes, or keratinocytes established from neoplastic lesions. However, infectious papillomavirus particles have only been isolated from organotypic epithelial cultures initiated with cells that maintain oncogenic human papillomavirus genomes in an extrachomosomal replicative form. The second section of this unit is dedicated to a virion isolation method that minimizes aerosol and skin exposure to these human carcinogens. Although the focus of the protocols is on the growth of tissues that yields infectious papillomavirus progeny, this culture system facilitates the investigation of these fastidious viruses during their complex replicative cycles, and raft tissues can be manipulated and harvested at any point during the process. Importantly, a single-step virus growth cycle is achieved in this process, as it is unlikely that progeny virions are released to initiate subsequent rounds of infection. Copyright © 2014 John Wiley & Sons, Inc.

Mitochondrial dysfunction: the missing link between aging and sporadic Alzheimer's disease.

PubMed

Grimm, Amandine; Friedland, Kristina; Eckert, Anne

2016-04-01

Alzheimer's disease (AD) is a progressive neurodegenerative disease that represents the most common form of dementia among the elderly. Despite the fact that AD was studied for decades, the underlying mechanisms that trigger this neuropathology remain unresolved. Since the onset of cognitive deficits occurs generally within the 6th decade of life, except in rare familial case, advancing age is the greatest known risk factor for AD. To unravel the pathogenesis of the disease, numerous studies use cellular and animal models based on genetic mutations found in rare early onset familial AD (FAD) cases that represent less than 1 % of AD patients. However, the underlying process that leads to FAD appears to be distinct from that which results in late-onset AD. As a genetic disorder, FAD clearly is a consequence of malfunctioning/mutated genes, while late-onset AD is more likely due to a gradual accumulation of age-related malfunction. Normal aging and AD are both marked by defects in brain metabolism and increased oxidative stress, albeit to varying degrees. Mitochondria are involved in these two phenomena by controlling cellular bioenergetics and redox homeostasis. In the present review, we compare the common features observed in both brain aging and AD, placing mitochondrial in the center of pathological events that separate normal and pathological aging. We emphasize a bioenergetic model for AD including the inverse Warburg hypothesis which postulates that AD is a consequence of mitochondrial deregulation leading to metabolic reprogramming as an initial attempt to maintain neuronal integrity. After the failure of this compensatory mechanism, bioenergetic deficits may lead to neuronal death and dementia. Thus, mitochondrial dysfunction may represent the missing link between aging and sporadic AD, and represent attractive targets against neurodegeneration.

Cadmium accumulation, sub-cellular distribution and chemical forms in rice seedling in the presence of sulfur.

PubMed

Zhang, Wen; Lin, Kuangfei; Zhou, Jian; Zhang, Wei; Liu, Lili; Zhang, Qianqian

2014-01-01

Changes in cadmium (Cd) accumulation, distribution, and chemical form in rice seedling in the joint presence of different concentrations of sulfur (S) remain almost unknown. Therefore, the indoor experiments were performed to determine the accumulation, sub-cellular distribution and chemical forms of Cd under three S levels in rice seedling for the first time. The result showed that Cd accumulation in rice roots was more than in shoots. Sub-cellular distribution of Cd in rice roots and shoots indicated that the largest proportion of Cd accumulated in cell walls and soluble fractions. As S supply increased, the proportion of Cd in cell walls reduced, while it increased in the soluble fractions. The majority of Cd existed in inorganic form, and then gradually changed to organic forms that included pectates and proteins with increased S supply. The results showed that S supply significantly influenced Cd accumulation, distribution, and chemical forms, suggesting that S might provide the material for the synthesis of sulfhydryl protein and thereby affect Cd stress on plants. These observations provided a basic understanding of potential ecotoxicological effects of joint Cd and S exposure in the environment. Copyright © 2013 Elsevier B.V. All rights reserved.

Kinetic theory approach to modeling of cellular repair mechanisms under genome stress.

PubMed

Qi, Jinpeng; Ding, Yongsheng; Zhu, Ying; Wu, Yizhi

2011-01-01

Under acute perturbations from outer environment, a normal cell can trigger cellular self-defense mechanism in response to genome stress. To investigate the kinetics of cellular self-repair process at single cell level further, a model of DNA damage generating and repair is proposed under acute Ion Radiation (IR) by using mathematical framework of kinetic theory of active particles (KTAP). Firstly, we focus on illustrating the profile of Cellular Repair System (CRS) instituted by two sub-populations, each of which is made up of the active particles with different discrete states. Then, we implement the mathematical framework of cellular self-repair mechanism, and illustrate the dynamic processes of Double Strand Breaks (DSBs) and Repair Protein (RP) generating, DSB-protein complexes (DSBCs) synthesizing, and toxins accumulating. Finally, we roughly analyze the capability of cellular self-repair mechanism, cellular activity of transferring DNA damage, and genome stability, especially the different fates of a certain cell before and after the time thresholds of IR perturbations that a cell can tolerate maximally under different IR perturbation circumstances.

A Comparison of Raman Spectral Features of Frozen and Deparaffinized Tissues in Neuroblastoma and Ganglioneuroma

NASA Astrophysics Data System (ADS)

Devpura, Suneetha; Thakur, Jagdish S.; Poulik, Janet M.; Rabah, Raja; Naik, Vaman M.; Naik, Ratna

2012-02-01

We have investigated the cellular regions in neuroblastoma and ganglioneuroma using Raman spectroscopy and compared their spectral characteristics with those of normal adrenal gland. Thin sections from both frozen and deparaffinized tissues, obtained from the same tissue specimen, were studied in conjunction with the pathological examination of the tissues. We found a significant difference in the spectral features of frozen sections of normal adrenal gland, neuroblastoma, and ganglioneuroma when compared to deparaffinized tissues. The quantitative analysis of the Raman data using chemometric methods of principal component analysis and discriminant function analysis obtained from the frozen tissues show a sensitivity and specificity of 100% each. The biochemical identification based on the spectral differences shows that the normal adrenal gland tissues have higher levels of carotenoids, lipids, and cholesterol compared to the neuroblastoma and ganglioneuroma frozen tissues. However, deparaffinized tissues show complete removal of these biochemicals in adrenal tissues. This study demonstrates that Raman spectroscopy combined with chemometric methods can successfully distinguish neuroblastoma and ganglioneuroma at cellular level.

Neural control of renal tubular solute and water transport.

PubMed

DiBona, G F

1989-01-01

The neural control of renal tubular solute and water transport is recognized as an important physiological mechanism in the overall regulation of solute and water homeostasis by the mammalian organism. Recent studies have expanded the understanding of this mechanism concerning the transport of diverse solutes with beginning insight into the precise nature of the cellular transport processes involved. The modulatory roles of both circulating and intrarenal hormonal systems on the responses to alterations in the magnitude of efferent renal sympathetic nerve activity are being understood from the nerve terminal release of neurotransmitter to influences on cellular transport processes which determine the overall effect. When dietary sodium intake is normal or only modestly reduced, intact renal innervation is not essential for normal renal sodium conservation. However, when dietary sodium intake is severely restricted, there is maximum engagement of all mechanisms known to participate in renal sodium conservation and, under these conditions, intact renal innervation is essential for normal renal sodium conservation.

Discovery of a New Cellular Motion and Its Relevance to Breast Cancer and Involution

DTIC Science & Technology

2014-02-01

motion (CAMo), live cell imaging , confocal microscopy Overall Project Summary: During this first year of funding we have concentrated our work to...cell types in 3D cultures and in vivo. Subtask 1.1a: Real time live cell imaging using confocal microscopy will be used to image cellular movement...exciting as they are important steps in understanding behavior of normal myoepithelial cells using live cell imaging in physiologically

Mapping of oxidative stress response elements of the caveolin-1 promoter.

PubMed

Bartholomew, Janine N; Galbiati, Ferruccio

2010-01-01

According to the "free radical theory" of aging, normal aging occurs as the result of tissue damages inflicted by reactive oxygen species (ROS). ROS are known to induce cellular senescence, and senescent cells are believed to contribute to organismal aging. The molecular mechanisms that mediate the cellular response to oxidants remain to be fully identified. We have shown that oxidative stress induces cellular senescence through activation of the caveolin-1 promoter and upregulation of caveolin-1 protein expression. Here, we describe how reactive oxygen species activate the caveolin-1 promoter and how the signaling may be assayed. These approaches provide insight into the functional role of caveolin-1 and potentially allow the identification of novel ROS-regulated genes that are part of the signaling machinery regulating cellular senescence/aging.

PKCλ/ι signaling-a common node for normal cellular development and breast oncogenesis.

PubMed

Paul, Arindam; Paul, Soumen

2015-01-01

We recently demonstrated that PKCλ/ι signaling is an important contributor to breast cancer development. Strikingly, PKCλ/ι signaling is also important to balance self-renewal versus differentiation in pluripotent stem cells and is essential for embryonic development. This commentary highlights some key functions of PKCλ/ι signaling that are integral to both normal development and cancer progression.

Basement Membrane Type IV Collagen and Laminin: An Overview of Their Biology and Value as Fibrosis Biomarkers of Liver Disease.

PubMed

Mak, Ki M; Mei, Rena

2017-08-01

Basement membranes provide structural support to epithelium, endothelium, muscles, fat cells, Schwann cells, and axons. Basement membranes are multifunctional: they modulate cellular behavior, regulate organogenesis, promote tissue repair, form a barrier to filtration and tumor metastasis, bind growth factors, and mediate angiogenesis. All basement membranes contain type IV collagen (Col IV), laminin, nidogen, and perlecan. Col IV and laminin self-assemble into two independent supramolecular networks that are linked to nidogen and perlecan to form a morphological discernable basement membrane/basal lamina. The triple helical region, 7S domain and NCI domain of Col IV, laminin and laminin fragment P1 have been evaluated as noninvasive fibrosis biomarkers of alcoholic liver disease, viral hepatitis, and nonalcoholic fatty liver disease. Elevated serum Col IV and laminin are related to degrees of fibrosis and severity of hepatitis, and may reflect hepatic basement membrane metabolism. But the serum assays have not been linked to disclosing the anatomical sites and lobular distribution of perisinusoidal basement membrane formation in the liver. Hepatic sinusoids normally lack a basement membrane, although Col IV is a normal matrix component of the space of Disse. In liver disease, laminin deposits in the space of Disse and codistributes with Col IV, forming a perisinusoidal basement membrane. Concomitantly, the sinusoidal endothelium loses its fenestrae and is transformed into vascular type endothelium. These changes lead to capillarization of hepatic sinusoids, a significant pathology that impairs hepatic function. Accordingly, codistribution of Col IV and laminin serves as histochemical marker of perisinusoidal basement membrane formation in liver disease. Anat Rec, 300:1371-1390, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Enhancing the Biological Relevance of Secretome-Based Proteomics by Linking Tumor Cell Proliferation and Protein Secretion.

PubMed

Gregori, Josep; Méndez, Olga; Katsila, Theodora; Pujals, Mireia; Salvans, Cándida; Villarreal, Laura; Arribas, Joaquin; Tabernero, Josep; Sánchez, Alex; Villanueva, Josep

2014-07-15

Secretome profiling has become a methodology of choice for the identification of tumor biomarkers. We hypothesized that due to the dynamic nature of secretomes cellular perturbations could affect their composition but also change the global amount of protein secreted per cell. We confirmed our hypothesis by measuring the levels of secreted proteins taking into account the amount of proteome produced per cell. Then, we established a correlation between cell proliferation and protein secretion that explained the observed changes in global protein secretion. Next, we implemented a normalization correcting the statistical results of secretome studies by the global protein secretion of cells into a generalized linear model (GLM). The application of the normalization to two biological perturbations on tumor cells resulted in drastic changes in the list of statistically significant proteins. Furthermore, we found that known epithelial-to-mesenchymal transition (EMT) effectors were only statistically significant when the normalization was applied. Therefore, the normalization proposed here increases the sensitivity of statistical tests by increasing the number of true-positives. From an oncology perspective, the correlation between protein secretion and cellular proliferation suggests that slow-growing tumors could have high-protein secretion rates and consequently contribute strongly to tumor paracrine signaling.

Genetic analysis of indefinite division in human cells: Evidence for a cell senescence-related gene(s) on human chromosome 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yi Ning; Ledbetter, D.H.; Smith, J.R.

1991-07-01

Earlier studies had demonstrated that fusion of normal with immortal human cells yielded hybrids having limited division potential. This indicated that the phenotype of limited proliferation (cellular senescence) is dominant and that immortal cells result from recessive changes in normal growth-regulatory genes. In additional studies, the authors exploited the fact that the immortal phenotype is recessive and, by fusing various immortal human cell lines with each other, identified four complementation groups for indefinite division. Assignment of cell lines to specific groups allowed us to take a focused approach to identify the chromosomes and genes involved in growth regulation that havemore » been modified in immortal cells. They report here that introduction of a normal human chromosome 4 into three immortal cell lines (HeLa, J82, T98G) assigned to complementation group B resulted in loss of proliferation and reversal of the immortal phenotype. No effect on the proliferation potential of cell lines representative of the other complementation groups was observed. This result suggests that a gene(s) involved in cellular senescence and normal growth regulation resides on chromosome 4.« less

The biophysical bases of will-less behaviors

PubMed Central

Perez Velazquez, José L.

2012-01-01

Are there distinctions at the neurophysiological level that correlate with voluntary and involuntary actions? Whereas the wide variety of involuntary behaviors (and here mostly the deviant or pathological ones will be considered) will necessarily be represented at some biophysical level in nervous system activity–for after all those cellular activity patterns manifest themselves as behaviors and thus there will be a multiplicity of them–there could be some general tendencies to be discerned amongst that assortment. Collecting observations derived from neurophysiological activity associated with several pathological conditions characterized by presenting will-less actions such as Parkinson's disease, seizures, alien hand syndrome and tics, it is proposed that a general neurophysiologic tendency of brain activity that correlates with involuntary actions is higher than normal synchrony in specific brain cell networks, depending upon the behavior in question. Wilful, considered normal behavior, depends on precise coordination of the collective activity in cell ensembles that may be lost, or diminished, when there are tendencies toward more than normal or aberrant synchronization of cellular activity. Hence, rapid fluctuations in synchrony is associated with normal actions and cognition while less variability in brain recordings particularly with regards to synchronization could be a signature of unconscious and deviant behaviors in general. PMID:23109920

Manufacturing of Proteins and Antibodies: Chapter Downstream Processing Technologies : Harvest Operations.

PubMed

Turner, Richard; Joseph, Adrian; Titchener-Hooker, Nigel; Bender, Jean

2017-08-04

Cell harvesting is the separation or retention of cells and cellular debris from the supernatant containing the target molecule Selection of harvest method strongly depends on the type of cells, mode of bioreactor operation, process scale, and characteristics of the product and cell culture fluid. Most traditional harvesting methods use some form of filtration, centrifugation, or a combination of both for cell separation and/or retention. Filtration methods include normal flow depth filtration and tangential flow microfiltration. The ability to scale down predictably the selected harvest method helps to ensure successful production and is critical for conducting small-scale characterization studies for confirming parameter targets and ranges. In this chapter we describe centrifugation and depth filtration harvesting methods, share strategies for harvest optimization, present recent developments in centrifugation scale-down models, and review alternative harvesting technologies.

Vertical temperature boundary of the pseudogap under the superconducting dome in the phase diagram of Bi 2 Sr 2 CaCu 2 O 8 + δ

DOE PAGES

Loret, B.; Sakai, S.; Benhabib, S.; ...

2017-09-25

We combine electronic Raman scattering experiments with cellular dynamical mean field theory and present evidence of the pseudogap in the superconducting state of various hole-doped cuprates. In Bi 2 Sr 2 CaCu 2 O 8 + δ we also track the superconducting pseudogap hallmark, a peak-dip feature, as a function of temperature T and doping p , well beyond the optimal one. We show that, at all temperatures under the superconducting dome, the pseudogap disappears at the doping p c , between 0.222 and 0.226, where also the normal-state pseudogap collapses at a Lifshitz transition. This demonstrates that the superconductingmore » pseudogap boundary forms a vertical line in the T - p phase diagram.« less

Role of Lipid Peroxidation-Derived α, β-Unsaturated Aldehydes in Vascular Dysfunction

PubMed Central

Lee, Seung Eun; Park, Yong Seek

2013-01-01

Vascular diseases are the most prominent cause of death, and inflammation and vascular dysfunction are key initiators of the pathophysiology of vascular disease. Lipid peroxidation products, such as acrolein and other α, β-unsaturated aldehydes, have been implicated as mediators of inflammation and vascular dysfunction. α, β-Unsaturated aldehydes are toxic because of their high reactivity with nucleophiles and their ability to form protein and DNA adducts without prior metabolic activation. This strong reactivity leads to electrophilic stress that disrupts normal cellular function. Furthermore, α, β-unsaturated aldehydes are reported to cause endothelial dysfunction by induction of oxidative stress, redox-sensitive mechanisms, and inflammatory changes such as induction of cyclooxygenase-2 and cytokines. This review provides an overview of the effects of lipid peroxidation products, α, β-unsaturated aldehydes, on inflammation and vascular dysfunction. PMID:23819013

Metabolic features of the cell danger response.

PubMed

Naviaux, Robert K

2014-05-01

The cell danger response (CDR) is the evolutionarily conserved metabolic response that protects cells and hosts from harm. It is triggered by encounters with chemical, physical, or biological threats that exceed the cellular capacity for homeostasis. The resulting metabolic mismatch between available resources and functional capacity produces a cascade of changes in cellular electron flow, oxygen consumption, redox, membrane fluidity, lipid dynamics, bioenergetics, carbon and sulfur resource allocation, protein folding and aggregation, vitamin availability, metal homeostasis, indole, pterin, 1-carbon and polyamine metabolism, and polymer formation. The first wave of danger signals consists of the release of metabolic intermediates like ATP and ADP, Krebs cycle intermediates, oxygen, and reactive oxygen species (ROS), and is sustained by purinergic signaling. After the danger has been eliminated or neutralized, a choreographed sequence of anti-inflammatory and regenerative pathways is activated to reverse the CDR and to heal. When the CDR persists abnormally, whole body metabolism and the gut microbiome are disturbed, the collective performance of multiple organ systems is impaired, behavior is changed, and chronic disease results. Metabolic memory of past stress encounters is stored in the form of altered mitochondrial and cellular macromolecule content, resulting in an increase in functional reserve capacity through a process known as mitocellular hormesis. The systemic form of the CDR, and its magnified form, the purinergic life-threat response (PLTR), are under direct control by ancient pathways in the brain that are ultimately coordinated by centers in the brainstem. Chemosensory integration of whole body metabolism occurs in the brainstem and is a prerequisite for normal brain, motor, vestibular, sensory, social, and speech development. An understanding of the CDR permits us to reframe old concepts of pathogenesis for a broad array of chronic, developmental, autoimmune, and degenerative disorders. These disorders include autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), asthma, atopy, gluten and many other food and chemical sensitivity syndromes, emphysema, Tourette's syndrome, bipolar disorder, schizophrenia, post-traumatic stress disorder (PTSD), chronic traumatic encephalopathy (CTE), traumatic brain injury (TBI), epilepsy, suicidal ideation, organ transplant biology, diabetes, kidney, liver, and heart disease, cancer, Alzheimer and Parkinson disease, and autoimmune disorders like lupus, rheumatoid arthritis, multiple sclerosis, and primary sclerosing cholangitis. © 2013. Published by Elsevier B.V. All rights reserved.

Downregulation of Metabolic Activity Increases Cell Survival Under Hypoxic Conditions: Potential Applications for Tissue Engineering

PubMed Central

Kim, Jaehyun; Andersson, Karl-Erik; Jackson, John D.; Lee, Sang Jin; Atala, Anthony

2014-01-01

A major challenge to the success of cell-based implants for tissue regeneration is an insufficient supply of oxygen before host vasculature is integrated into the implants, resulting in premature cell death and dysfunction. Whereas increasing oxygenation to the implants has been a major focus in the field, our strategy is aimed at lowering oxygen consumption by downregulating cellular metabolism of cell-based implants. Adenosine, which is a purine nucleoside that functions as an energy transferring molecule, has been reported to increase under hypoxia, resulting in reducing the adenosine triphosphate (ATP) demands of the Na+/K+ ATPase. In the present study, we investigated whether adenosine could be used to downregulate cellular metabolism to achieve prolonged survival under hypoxic conditions. Murine myoblasts (C2C12) lacking a self-survival mechanism were treated with adenosine under 0.1% hypoxic stress. The cells, cultured in the presence of 5 mM adenosine, maintained their viability under hypoxia, and regained their normal growth and function of forming myotubes when transferred to normoxic conditions at day 11 without further supply of adenosine, whereas nontreated cells failed to survive. An increase in adenosine concentrations shortened the onset of reproliferation after transfer to normoxic conditions. This increase correlated with an increase in metabolic downregulation during the early phase of hypoxia. A higher intracellular ATP level was observed in adenosine-treated cells throughout the duration of hypoxia. This strategy of increasing cell survival under hypoxic conditions through downregulating cellular metabolism may be utilized for cell-based tissue regeneration applications as well as protecting tissues against hypoxic injuries. PMID:24524875

Heat shock factor-1 intertwines insulin/IGF-1, TGF-β and cGMP signaling to control development and aging.

PubMed

Barna, János; Princz, Andrea; Kosztelnik, Mónika; Hargitai, Balázs; Takács-Vellai, Krisztina; Vellai, Tibor

2012-11-01

Temperature affects virtually all cellular processes. A quick increase in temperature challenges the cells to undergo a heat shock response to maintain cellular homeostasis. Heat shock factor-1 (HSF-1) functions as a major player in this response as it activates the transcription of genes coding for molecular chaperones (also called heat shock proteins) that maintain structural integrity of proteins. However, the mechanisms by which HSF-1 adjusts fundamental cellular processes such as growth, proliferation, differentiation and aging to the ambient temperature remain largely unknown. We demonstrate here that in Caenorhabditis elegans HSF-1 represses the expression of daf-7 encoding a TGF-β (transforming growth factor-beta) ligand, to induce young larvae to enter the dauer stage, a developmentally arrested, non-feeding, highly stress-resistant, long-lived larval form triggered by crowding and starvation. Under favorable conditions, HSF-1 is inhibited by crowding pheromone-sensitive guanylate cyclase/cGMP (cyclic guanosine monophosphate) and systemic nutrient-sensing insulin/IGF-1 (insulin-like growth factor-1) signaling; loss of HSF-1 activity allows DAF-7 to promote reproductive growth. Thus, HSF-1 interconnects the insulin/IGF-1, TGF-β and cGMP neuroendocrine systems to control development and longevity in response to diverse environmental stimuli. Furthermore, HSF-1 upregulates another TGF-β pathway-interacting gene, daf-9/cytochrome P450, thereby fine-tuning the decision between normal growth and dauer formation. Together, these results provide mechanistic insight into how temperature, nutrient availability and population density coordinately influence development, lifespan, behavior and stress response through HSF-1.

Nonessential role of beta3 and beta5 integrin subunits for efficient clearance of cellular debris after light-induced photoreceptor degeneration.

PubMed

Joly, Sandrine; Samardzija, Marijana; Wenzel, Andreas; Thiersch, Markus; Grimm, Christian

2009-03-01

During light-induced photoreceptor degeneration, large amounts of cellular debris are formed that must be cleared from the subretinal space. The integrins alphavbeta5 and alphavbeta3 are involved in the normal physiological process of phagocytosis in the retina. This study was conducted to investigate the question of whether the lack of beta5 and/or beta3 integrin subunits might influence the course of retinal degeneration and/or clearance of photoreceptor debris induced by acute exposure to light. Wild-type, beta5(-/-) and beta3(-/-) single-knockout, and beta3(-/-)/beta5(-/-) Ccl2(-/-)/beta5(-/-) double-knockout mice were exposed to 13,000 lux of white light for 2 hours to induce severe photoreceptor degeneration. Real-time PCR and Western blot analysis were used to analyze gene and protein expression, light- and electron microscopy to judge retinal morphology, and immunofluorescence to study retinal distribution of proteins. Individual or combined deletion of beta3 and beta5 integrin subunits did not affect the pattern of photoreceptor cell loss or the clearance of photoreceptor debris in mice compared with that in wild-type mice. Invading macrophages may contribute to efficient phagocytosis. However, ablation of the MCP-1 gene did not prevent macrophage recruitment. Several chemokines in addition to MCP-1 were induced after light-induced damage that may have compensated for the deletion of MCP-1. Acute clearance of a large amount of cellular debris from the subretinal space involves invading macrophages and does not depend on beta3 and beta5 integrins.

Somatostatin-Positive Gamma-Aminobutyric Acid Interneuron Deficits in Depression: Cortical Microcircuit and Therapeutic Perspectives.

PubMed

Fee, Corey; Banasr, Mounira; Sibille, Etienne

2017-10-15

The functional integration of external and internal signals forms the basis of information processing and is essential for higher cognitive functions. This occurs in finely tuned cortical microcircuits whose functions are balanced at the cellular level by excitatory glutamatergic pyramidal neurons and inhibitory gamma-aminobutyric acidergic (GABAergic) interneurons. The balance of excitation and inhibition, from cellular processes to neural network activity, is characteristically disrupted in multiple neuropsychiatric disorders, including major depressive disorder (MDD), bipolar disorder, anxiety disorders, and schizophrenia. Specifically, nearly 3 decades of research demonstrate a role for reduced inhibitory GABA level and function across disorders. In MDD, recent evidence from human postmortem and animal studies suggests a selective vulnerability of GABAergic interneurons that coexpress the neuropeptide somatostatin (SST). Advances in cell type-specific molecular genetics have now helped to elucidate several important roles for SST interneurons in cortical processing (regulation of pyramidal cell excitatory input) and behavioral control (mood and cognition). Here, we review evidence for altered inhibitory function arising from GABAergic deficits across disorders and specifically in MDD. We then focus on properties of the cortical microcircuit, where SST-positive GABAergic interneuron deficits may disrupt functioning in several ways. Finally, we discuss the putative origins of SST cell deficits, as informed by recent research, and implications for therapeutic approaches. We conclude that deficits in SST interneurons represent a contributing cellular pathology and therefore a promising target for normalizing altered inhibitory function in MDD and other disorders with reduced SST cell and GABA functions. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Solid phase extraction for the speciation and preconcentration of inorganic selenium in water samples: a review.

PubMed

Herrero Latorre, C; Barciela García, J; García Martín, S; Peña Crecente, R M

2013-12-04

Selenium is an essential element for the normal cellular function of living organisms. However, selenium is toxic at concentrations of only three to five times higher than the essential concentration. The inorganic forms (mainly selenite and selenate) present in environmental water generally exhibit higher toxicity (up to 40 times) than organic forms. Therefore, the determination of low levels of different inorganic selenium species in water is an analytical challenge. Solid-phase extraction has been used as a separation and/or preconcentration technique prior to the determination of selenium species due to the need for accurate measurements for Se species in water at extremely low levels. The present paper provides a critical review of the published methods for inorganic selenium speciation in water samples using solid phase extraction as a preconcentration procedure. On the basis of more than 75 references, the different speciation strategies used for this task have been highlighted and classified. The solid-phase extraction sorbents and the performance and analytical characteristics of the developed methods for Se speciation are also discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

Defining the cause of skewed X-chromosome inactivation in X-linked mental retardation by use of a mouse model.

PubMed

Muers, Mary R; Sharpe, Jacqueline A; Garrick, David; Sloane-Stanley, Jacqueline; Nolan, Patrick M; Hacker, Terry; Wood, William G; Higgs, Douglas R; Gibbons, Richard J

2007-06-01

Extreme skewing of X-chromosome inactivation (XCI) is rare in the normal female population but is observed frequently in carriers of some X-linked mutations. Recently, it has been shown that various forms of X-linked mental retardation (XLMR) have a strong association with skewed XCI in female carriers, but the mechanisms underlying this skewing are unknown. ATR-X syndrome, caused by mutations in a ubiquitously expressed, chromatin-associated protein, provides a clear example of XLMR in which phenotypically normal female carriers virtually all have highly skewed XCI biased against the X chromosome that harbors the mutant allele. Here, we have used a mouse model to understand the processes causing skewed XCI. In female mice heterozygous for a null Atrx allele, we found that XCI is balanced early in embryogenesis but becomes skewed over the course of development, because of selection favoring cells expressing the wild-type Atrx allele. Unexpectedly, selection does not appear to be the result of general cellular-viability defects in Atrx-deficient cells, since it is restricted to specific stages of development and is not ongoing throughout the life of the animal. Instead, there is evidence that selection results from independent tissue-specific effects. This illustrates an important mechanism by which skewed XCI may occur in carriers of XLMR and provides insight into the normal role of ATRX in regulating cell fate.

Loss of the E3 ubiquitin ligase LRSAM1 sensitizes peripheral axons to degeneration in a mouse model of Charcot-Marie-Tooth disease.

PubMed

Bogdanik, Laurent P; Sleigh, James N; Tian, Cong; Samuels, Mark E; Bedard, Karen; Seburn, Kevin L; Burgess, Robert W

2013-05-01

Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous condition characterized by peripheral axon degeneration with subsequent motor and sensory deficits. Several CMT gene products function in endosomal sorting and trafficking to the lysosome, suggesting that defects in this cellular pathway might present a common pathogenic mechanism for these conditions. LRSAM1 is an E3 ubiquitin ligase that is implicated in this process, and mutations in LRSAM1 have recently been shown to cause CMT. We have generated mouse mutations in Lrsam1 to create an animal model of this form of CMT (CMT2P). Mouse Lrsam1 is abundantly expressed in the motor and sensory neurons of the peripheral nervous system. Both homozygous and heterozygous mice have largely normal neuromuscular performance and only a very mild neuropathy phenotype with age. However, Lrsam1 mutant mice are more sensitive to challenge with acrylamide, a neurotoxic agent that causes axon degeneration, indicating that the axons in the mutant mice are indeed compromised. In transfected cells, LRSAM1 primarily localizes in a perinuclear compartment immediately beyond the Golgi and shows little colocalization with components of the endosome to lysosome trafficking pathway, suggesting that other cellular mechanisms also merit consideration.

Developing and applying the adverse outcome pathway ...

EPA Pesticide Factsheets

To support a paradigm shift in regulatory toxicology testing and risk assessment, the Adverse Outcome Pathway (AOP) concept has recently been proposed. This concept is similar to that for Mode of Action (MOA), describing a sequence of measurable key events triggered by a molecular initiating event in which a stressor interacts with a biological target. The resulting cascade of key events includes molecular, cellular, structural and functional changes in biological systems, resulting in a measurable adverse outcome. Thereby, an AOP ideally provides information relevant to chemical structure-activity relationships as a basis to predict effects for structurally similar compounds. AOPs could potentially also form the basis for qualitative and quantitative predictive modeling of the human adverse outcome resulting from molecular initiating or other key events for which higher-throughput testing methods are available or can be developed.A variety of cellular and molecular processes are known to be critical to normal function of the central (CNS) and peripheral nervous systems (PNS). Because of the biological and functional complexity of the CNS and PNS, it has been challenging to establish causative links and quantitative relationships between key events that comprise the pathways leading from chemical exposure to an adverse outcome in the nervous system. Following introduction of principles of the description and assessment of MOA and AOPs, examples of adverse out

Chemiluminometric Immuno-Analysis of Innate Immune Response against Repetitive Bacterial Stimulations for the Same Mammalian Cells

PubMed Central

Jeon, Jin-Woo; Cho, Il-Hoon; Ha, Un-Hwan; Seo, Sung-Kyu; Paek, Se-Hwan

2014-01-01

For monitoring of human cellular response to repetitive bacterial stimulations (e.g., Pseudomonas aeruginosa in a lysate form), we devised a chemiluminescent immuno-analytical system for toll-like receptor 1 (TLR1) as marker present on cell surfaces (e.g., A549). Upon stimulation, TLR1 recognizes pathogen-associated molecular patterns of the infectious agent and are then up-regulated via activation of the nuclear factor-κB (NF-κB) pathway. In this study, the receptor density was quantified by employing an antibody specific to the target receptor and by producing a chemiluminometric signal from an enzyme labeled to the binder. The activated status was then switched back to normal down-regulated stage, by changing the culture medium to one containing animal serum. The major factors affecting activation were the stimulation dose of the bacterial lysate, stimulation timing during starvation, and up- and down-regulation time intervals. Reiterative TLR regulation switching up to three times was not affected by either antibody remained after immunoassay or enzyme substrate (e.g., hydrogen peroxide) in solution. This immuno-analysis for TLRs could be unique to acquire accumulated response of the human cells to repeated stimulations and, therefore, can eventually apply to persistency testing of the cellular regulation in screening of anti-inflammatory substances. PMID:25109895

Networking Omic Data to Envisage Systems Biological Regulation.

PubMed

Kalapanulak, Saowalak; Saithong, Treenut; Thammarongtham, Chinae

To understand how biological processes work, it is necessary to explore the systematic regulation governing the behaviour of the processes. Not only driving the normal behavior of organisms, the systematic regulation evidently underlies the temporal responses to surrounding environments (dynamics) and long-term phenotypic adaptation (evolution). The systematic regulation is, in effect, formulated from the regulatory components which collaboratively work together as a network. In the drive to decipher such a code of lives, a spectrum of technologies has continuously been developed in the post-genomic era. With current advances, high-throughput sequencing technologies are tremendously powerful for facilitating genomics and systems biology studies in the attempt to understand system regulation inside the cells. The ability to explore relevant regulatory components which infer transcriptional and signaling regulation, driving core cellular processes, is thus enhanced. This chapter reviews high-throughput sequencing technologies, including second and third generation sequencing technologies, which support the investigation of genomics and transcriptomics data. Utilization of this high-throughput data to form the virtual network of systems regulation is explained, particularly transcriptional regulatory networks. Analysis of the resulting regulatory networks could lead to an understanding of cellular systems regulation at the mechanistic and dynamics levels. The great contribution of the biological networking approach to envisage systems regulation is finally demonstrated by a broad range of examples.

SUMO proteases as potential targets for cancer therapy.

PubMed

Bialik, Piotr; Woźniak, Katarzyna

2017-12-08

Sumoylation is one of the post-translational modifications of proteins, responsible for the regulation of many cellular processes, such as DNA replication and repair, transcription, signal transduction and nuclear transport. During sumoylation, SUMO proteins are covalently attached to the ε-amino group of lysine in target proteins via an enzymatic cascade that requires the sequential action of E1, E2 and E3 enzymes. An important aspect of sumoylation is its reversibility, which involves SUMO-specific proteases called SENPs. SENPs (sentrin/SUMO-specific proteases) catalyze the deconjugation of SUMO proteins using their isopeptidase activity. These enzymes participate through hydrolase activity in the reaction of SUMO protein maturation, which involves the removal of a short fragment on the C-terminus of SUMO inactive form and exposure two glycine residues. SENPs are important for maintaining the balance between sumoylated and desumoylated proteins required for normal cellular physiology. Six SENP isoforms (SENP1, SENP2, SENP3, SENP5, SENP6 and SENP7) have been identified in mammals. These SENPs can be divided into three subfamilies based on their sequence homology, substrate specificity and subcellular localization. Results of studies indicate the role of SUMO proteases in the development of human diseases including cancer, suggesting that these proteins may be attractive targets for new drugs.

MYELIN IN THE CENTRAL NERVOUS SYSTEM AS OBSERVED IN EXPERIMENTALLY INDUCED EDEMA IN THE RAT

PubMed Central

Hirano, Asao; Zimmerman, H. M.; Levine, Seymour

1966-01-01

The compact arrangement of cells in the normal white matter of the brain makes an analysis of cellular architecture difficult. To overcome this difficulty, cerebral edema was induced in rats by means of the unilateral intracerebral implantation of silver nitrate. Within 48 hr, the brains were fixed by perfusion with glutaraldehyde followed by immersion in Dalton's chrome-osmium. Sections of the callosal radiations were studied in the electron microscope. The untreated hemisphere appeared entirely unaltered, whereas in the edematous hemisphere the edema fluid separated individual cell processes and small groups of them. The myelin sheaths and their relationships to the axons appeared essentially unaltered. In this material, analysis of cellular architecture was relatively easy, and the widely held theory of spiral wrapping could be confirmed. In addition, several other aspects of the myelin and myelin-forming cell relationships became apparent in the edematous tissue. Most of these were later confirmed by extensive and careful study of the nonedematous tissue. These included the presence of occasional isolated cytoplasmic areas in myelin and the presence of two complete sheaths around a single axon. Other observations, such as the appearance of mitochondria and dense bodies within the outer loop and the separation of myelin lamellae, are apparently limited to the edematous tissue. PMID:5971641

RHIM-based protein:protein interactions in anti-microbial defence against programmed cell death by necroptosis.

PubMed

Baker, Max O D G; Shanmugam, Nirukshan; Pham, Chi L L; Strange, Merryn; Steain, Megan; Sunde, Margaret

2018-05-05

The Receptor-interacting protein kinase Homotypic Interaction Motif (RHIM) is an amino acid sequence that mediates multiple protein:protein interactions in the mammalian programmed cell death pathway known as necroptosis. At least one key RHIM-based complex has been shown to have a functional amyloid fibril structure, which provides a stable hetero-oligomeric platform for downstream signaling. RHIMs and related motifs are present in immunity-related proteins across nature, from viruses to fungi to metazoans. Necroptosis is a hallmark feature of cellular clearance of infection. For this reason, numerous pathogens, including viruses and bacteria, have developed varied methods to modulate necroptosis, focusing on inhibiting RHIM:RHIM interactions, and thus their downstream cell death effects. This review will discuss current understanding of RHIM:RHIM interactions in normal cellular activation of necroptosis, from a structural and cell biology perspective. It will compare the mechanisms by which pathogens subvert these interactions in order to maintain their replicative and infective cycles and consider the similarities between RHIMs and other functional amyloid-forming proteins associated with cell death and innate immunity. It will discuss the implications of the heteromeric nature and structure of RHIM-based amyloid complexes in the context of other functional amyloids. Copyright © 2018. Published by Elsevier Ltd.

Mapping human brain capillary water lifetime: high‐resolution metabolic neuroimaging

PubMed Central

Li, Xin; Sammi, Manoj K.; Bourdette, Dennis N.; Neuwelt, Edward A.

2015-01-01

Shutter‐speed analysis of dynamic‐contrast‐agent (CA)‐enhanced normal, multiple sclerosis (MS), and glioblastoma (GBM) human brain data gives the mean capillary water molecule lifetime (τ b) and blood volume fraction (v b; capillary density–volume product (ρ † V)) in a high‐resolution 1H2O MRI voxel (40 μL) or ROI. The equilibrium water extravasation rate constant, k po (τ b −1), averages 3.2 and 2.9 s−1 in resting‐state normal white matter (NWM) and gray matter (NGM), respectively (n = 6). The results (italicized) lead to three major conclusions. (A) k po differences are dominated by capillary water permeability (P W †), not size, differences. NWM and NGM voxel k po and vb values are independent. Quantitative analyses of concomitant population‐averaged k po, vb variations in normal and normal‐appearing MS brain ROIs confirm PW † dominance. (B) P W † is dominated (>95%) by a trans(endothelial)cellular pathway, not the P CA † paracellular route. In MS lesions and GBM tumors, PCA † increases but PW † decreases. (C) k po tracks steady‐state ATP production/consumption flux per capillary. In normal, MS, and GBM brain, regional k po correlates with literature MRSI ATP (positively) and Na + (negatively) tissue concentrations. This suggests that the PW † pathway is metabolically active. Excellent agreement of the relative NGM/NWM k po vb product ratio with the literature 31PMRSI‐MT CMRoxphos ratio confirms the flux property. We have previously shown that the cellular water molecule efflux rate constant (k io) is proportional to plasma membrane P‐type ATPase turnover, likely due to active trans‐membrane water cycling. With synaptic proximities and synergistic metabolic cooperativities, polar brain endothelial, neuroglial, and neuronal cells form “gliovascular units.” We hypothesize that a chain of water cycling processes transmits brain metabolic activity to k po, letting it report neurogliovascular unit Na+,K+‐ATPase activity. Cerebral k po maps represent metabolic (functional) neuroimages. The NGM 2.9 s−1 k po means an equilibrium unidirectional water efflux of ~1015 H2O molecules s−1 per capillary (in 1 μL tissue): consistent with the known ATP consumption rate and water co‐transporting membrane symporter stoichiometries. © 2015 The Authors NMR in Biomedicine Published by John Wiley & Sons Ltd. PMID:25914365

Cellular Location and Expression of Na+, K+-ATPase α Subunits Affect the Anti-Proliferative Activity of Oleandrin

PubMed Central

Yang, Peiying; Cartwright, Carrie; Efuet, Ekem; Hamilton, Stanley R.; Wistuba, Ignacio Ivan; Menter, David; Addington, Crandell; Shureiqi, Imad; Newman, Robert A.

2015-01-01

The purpose of this study was to investigate whether intracellular distribution of Na+, K+-ATPase α3 subunit, a receptor for cardiac glycosides including oleandrin, is differentially altered in cancer versus normal cells and whether this altered distribution can be therapeutically targeted to inhibit cancer cell survival. The cellular distribution of Na+, K+-ATPase α3 isoform was investigated in paired normal and cancerous mucosa biopsy samples from patients with lung and colorectal cancers by immunohistochemical staining. The effects of oleandrin on α3 subunit intracellular distribution, cell death, proliferation, and EKR phosphorylation were examined in differentiated and undifferentiated human colon cancer CaCO-2 cells. While Na+, K+-ATPase α3 isoform was predominantly located near the cytoplasmic membrane in normal human colon and lung epithelia, the expression of this subunit in their paired cancer epithelia was shifted to a peri-nuclear position in both a qualitative and quantitative manner. Similarly, distribution of α3 isoform was also shifted from a cytoplasmic membrane location in differentiated human colon cancer CaCO-2 cells to a peri-nuclear position in undifferentiated CaCO-2 cells. Intriguingly, oleandrin exerted threefold stronger anti-proliferative activity in undifferentiated CaCO-2 cells (IC50, 8.25 nM) than in differentiated CaCO-2 cells (IC50, >25 nM). Oleandrin (10 to 20 nM) caused an autophagic cell death and altered ERK phosphorylation in undifferentiated but not in differentiated CaCO-2 cells. These data demonstrate that the intracellular location of Na+, K+-ATPase α3 isoform is altered in human cancer versus normal cells. These changes in α3 cellular location and abundance may indicate a potential target of opportunity for cancer therapy. PMID:23073998

Rescue of the colony-stimulating factor 1 (CSF-1)-nullizygous mouse (Csf1(op)/Csf1(op)) phenotype with a CSF-1 transgene and identification of sites of local CSF-1 synthesis.

PubMed

Ryan, G R; Dai, X M; Dominguez, M G; Tong, W; Chuan, F; Chisholm, O; Russell, R G; Pollard, J W; Stanley, E R

2001-07-01

Colony-stimulating factor 1 (CSF-1) regulates the survival, proliferation, and differentiation of mononuclear phagocytes. It is expressed as a secreted glycoprotein or proteoglycan found in the circulation or as a biologically active cell-surface glycoprotein. To investigate tissue CSF-1 regulation, CSF-1-null Csf1(op)/Csf1(op) mice expressing transgenes encoding the full-length membrane-spanning CSF-1 precursor driven by 3.13 kilobases of the mouse CSF-1 promoter and first intron were characterized. Transgene expression corrected the gross osteopetrotic, neurologic, weight, tooth, and reproductive defects of Csf1(op)/Csf1(op) mice. Detailed analysis of one transgenic line revealed that circulating CSF-1, tissue macrophage numbers, hematopoietic tissue cellularity, and hematopoietic parameters were normalized. Tissue CSF-1 levels were normal except for elevations in 4 secretory tissues. Skin fibroblasts from the transgenic mice secreted normal amounts of CSF-1 but also expressed some cell-surface CSF-1. Also, lacZ driven by the same promoter/first intron revealed beta-galactosidase expression in hematopoietic, reproductive, and other tissue locations proximal to CSF-1 cellular targets, consistent with local regulation by CSF-1 at these sites. These studies indicate that the 3.13-kilobase promoter/first intron confers essentially normal CSF-1 expression. They also pinpoint new cellular sites of CSF-1 expression, including ovarian granulosa cells, mammary ductal epithelium, testicular Leydig cells, serous acinar cells of salivary gland, Paneth cells of the small intestine, as well as local sites in several other tissues.

Is the Cortical Deficit in Amblyopia Due to Reduced Cortical Magnification, Loss of Neural Resolution, or Neural Disorganization?

PubMed

Clavagnier, Simon; Dumoulin, Serge O; Hess, Robert F

2015-11-04

The neural basis of amblyopia is a matter of debate. The following possibilities have been suggested: loss of foveal cells, reduced cortical magnification, loss of spatial resolution of foveal cells, and topographical disarray in the cellular map. To resolve this we undertook a population receptive field (pRF) functional magnetic resonance imaging analysis in the central field in humans with moderate-to-severe amblyopia. We measured the relationship between averaged pRF size and retinal eccentricity in retinotopic visual areas. Results showed that cortical magnification is normal in the foveal field of strabismic amblyopes. However, the pRF sizes are enlarged for the amblyopic eye. We speculate that the pRF enlargement reflects loss of cellular resolution or an increased cellular positional disarray within the representation of the amblyopic eye. The neural basis of amblyopia, a visual deficit affecting 3% of the human population, remains a matter of debate. We undertook the first population receptive field functional magnetic resonance imaging analysis in participants with amblyopia and compared the projections from the amblyopic and fellow normal eye in the visual cortex. The projection from the amblyopic eye was found to have a normal cortical magnification factor, enlarged population receptive field sizes, and topographic disorganization in all early visual areas. This is consistent with an explanation of amblyopia as an immature system with a normal complement of cells whose spatial resolution is reduced and whose topographical map is disordered. This bears upon a number of competing theories for the psychophysical defect and affects future treatment therapies. Copyright © 2015 the authors 0270-6474/15/3514740-16$15.00/0.

Cell death during the postnatal morphogenesis of the normal rabbit kidney and in experimental renal polycystosis.

PubMed Central

García-Porrero, J A; Ojeda, J L; Hurlé, J M

1978-01-01

We have studied, by means of optic and electron microscopy, the normal and abnormal cell death that takes place during the postnatal morphogenesis of rabbit kidney, and in the experimental renal polycystosis produced by methylprednisolone acetate. In the normal kidney intertubular cell death can be observed during the first 20 days of the postnatal development. However, cell death in the normal metanephric blastema is a very rare event. In the polycystic kidney numerous dead cells can be seen between the third and forty eighth days after injection. The topography and morphology of the dead cells depend on the stage in the evolution of the disease. In the 'stage of renal immaturity', dying and dead cells are present in the nephrogenic tissue, in the dilating collecting tubules and in the intertubular spaces. In this stage the cellular pathology is essentially nuclear. In the stage of tubular cysts, the dead cells are mostly located in the walls of cysts, with some dead cells, but mostly cellular debris in their lumina. At this stage the cellular pathology is basically cytoplasmic. The dead cells are eventually digested by what appear to be phagocytes of tubular epithelial origin. It is suggested that cell death is an important factor in the evolution of the lesions of renal polycystosis induced by corticosteroids, and probably in the initiation of the pathological process as well. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 PMID:670065

Four domains: The fundamental unicell and Post-Darwinian Cognition-Based Evolution.

PubMed

Miller, William B; Torday, John S

2018-04-13

Contemporary research supports the viewpoint that self-referential cognition is the proper definition of life. From that initiating platform, a cohesive alternative evolutionary narrative distinct from standard Neodarwinism can be presented. Cognition-Based Evolution contends that biological variation is a product of a self-reinforcing information cycle that derives from self-referential attachment to biological information space-time with its attendant ambiguities. That information cycle is embodied through obligatory linkages among energy, biological information, and communication. Successive reiterations of the information cycle enact the informational architectures of the basic unicellular forms. From that base, inter-domain and cell-cell communications enable genetic and cellular variations through self-referential natural informational engineering and cellular niche construction. Holobionts are the exclusive endpoints of that self-referential cellular engineering as obligatory multicellular combinations of the essential Four Domains: Prokaryota, Archaea, Eukaryota and the Virome. Therefore, it is advocated that these Four Domains represent the perpetual object of the living circumstance rather than the visible macroorganic forms. In consequence, biology and its evolutionary development can be appraised as the continual defense of instantiated cellular self-reference. As the survival of cells is as dependent upon limitations and boundaries as upon any freedom of action, it is proposed that selection represents only one of many forms of cellular constraint that sustain self-referential integrity. Copyright © 2018 Elsevier Ltd. All rights reserved.

DNA double-strand break repair of blood lymphocytes and normal tissues analysed in a preclinical mouse model: implications for radiosensitivity testing.

PubMed

Rübe, Claudia E; Grudzenski, Saskia; Kühne, Martin; Dong, Xiaorong; Rief, Nicole; Löbrich, Markus; Rübe, Christian

2008-10-15

Radiotherapy is an effective cancer treatment, but a few patients suffer severe radiation toxicities in neighboring normal tissues. There is increasing evidence that the variable susceptibility to radiation toxicities is caused by the individual genetic predisposition, by subtle mutations, or polymorphisms in genes involved in cellular responses to ionizing radiation. Double-strand breaks (DSB) are the most deleterious form of radiation-induced DNA damage, and DSB repair deficiencies lead to pronounced radiosensitivity. Using a preclinical mouse model, the highly sensitive gammaH2AX-foci approach was tested to verify even subtle, genetically determined DSB repair deficiencies known to be associated with increased normal tissue radiosensitivity. By enumerating gammaH2AX-foci in blood lymphocytes and normal tissues (brain, lung, heart, and intestine), the induction and repair of DSBs after irradiation with therapeutic doses (0.1-2 Gy) was investigated in repair-proficient and repair-deficient mouse strains in vivo and blood samples irradiated ex vivo. gammaH2AX-foci analysis allowed to verify the different DSB repair deficiencies; even slight impairments caused by single polymorphisms were detected similarly in both blood lymphocytes and solid tissues, indicating that DSB repair measured in lymphocytes is valid for different and complex organs. Moreover, gammaH2AX-foci analysis of blood samples irradiated ex vivo was found to reflect repair kinetics measured in vivo and, thus, give reliable information about the individual DSB repair capacity. gammaH2AX analysis of blood and tissue samples allows to detect even minor genetically defined DSB repair deficiencies, affecting normal tissue radiosensitivity. Future studies will have to evaluate the clinical potential to identify patients more susceptible to radiation toxicities before radiotherapy.

Language learning impairments: integrating basic science, technology, and remediation.

PubMed

Tallal, P; Merzenich, M M; Miller, S; Jenkins, W

1998-11-01

One of the fundamental goals of the modern field of neuroscience is to understand how neuronal activity gives rise to higher cortical function. However, to bridge the gap between neurobiology and behavior, we must understand higher cortical functions at the behavioral level at least as well as we have come to understand neurobiological processes at the cellular and molecular levels. This is certainly the case in the study of speech processing, where critical studies of behavioral dysfunction have provided key insights into the basic neurobiological mechanisms relevant to speech perception and production. Much of this progress derives from a detailed analysis of the sensory, perceptual, cognitive, and motor abilities of children who fail to acquire speech, language, and reading skills normally within the context of otherwise normal development. Current research now shows that a dysfunction in normal phonological processing, which is critical to the development of oral and written language, may derive, at least in part, from difficulties in perceiving and producing basic sensory-motor information in rapid succession--within tens of ms (see Tallal et al. 1993a for a review). There is now substantial evidence supporting the hypothesis that basic temporal integration processes play a fundamental role in establishing neural representations for the units of speech (phonemes), which must be segmented from the (continuous) speech stream and combined to form words, in order for the normal development of oral and written language to proceed. Results from magnetic resonance imaging (MRI) and positron emission tomography (PET) studies, as well as studies of behavioral performance in normal and language impaired children and adults, will be reviewed to support the view that the integration of rapidly changing successive acoustic events plays a primary role in phonological development and disorders. Finally, remediation studies based on this research, coupled with neuroplasticity research, will be presented.

Characteristics of the uridine uptake system in normal and polyoma transformed hamster embryo cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemkin, J.A.

1973-01-01

The lability of the uridine uptake system in the normal and polyoma transformed hamster embryo fibroblast was studied. The major areas investigated were: the kinetic parameters of uridine transport, a comparison of changes in cellular ATP content by factors which modulate uridine uptake, and a comparison of the qualitative and quantitative effects of the same modulating agent on uridine transport, cell growth, and cellular ATP content. Uridine uptake into cells in vitro was examined using tritiated uridine as a tracer to measure the amount of uridine incorporated into the acid soluble and acid-insoluble fractions of the cells studied. The ATPmore » content of the cells was determined by the firefly bioluminescence method. It was found that the K/sub t/ for uridine uptake into the normal hamster embryo cell and two polyoma transformed hamster embryo cell lines was identical. However, the V/sub max/ for uridine transport was higher in both polyoma transformed cell lines. Furthermore, the K/sub t/ in both the normal and transformed cell cultured in serum-less or serum-containing media was identical, although the V/sub max/ was higher in the serum-stimulated cell in both the normal and transformed cell. Stimulation of the normal cell with adenosine produced a different K/sub t/ for uridine transport. Preliminary investigations have demonstrated that treatment of the polyoma transformed with adenosine also induces a different K/sub t/ (not shown). The K/sub i/ for phloretin inhibition in serum-less and serum-stimulated normal and polyoma transformed cells was found to be identical in each case.« less

Strong enhancement of dispersion forces from microwave radiation

NASA Astrophysics Data System (ADS)

Sernelius, B. E.

2002-11-01

We have studied non-thermal effects of microwave radiation on the forces between objects. This is the first step in a study of possible effects of microwave radiation from cellular phones on biological tissue. We have used a simplified model for human blood cells in blood. We find for the normal radiation level of cellular phones an enhancement of the attractive force with ten orders of magnitude as compared to the corresponding effect at thermal radiation.

The Effects of Storage on Irradiated Red Blood Cells: An In Vitro and In Vivo Study

DTIC Science & Technology

1991-08-01

nerve impulses, and is involved with cellular menbrane potential. It also influences and is influenced by the acid base balance. 19 Normal serum...maintained by active transport of scdium and potassium across the cell menbrane . Sodium is punped out and potassium pumped into the cell. The body’s...insufficiency or failure; renal dialysis is often required to remove 4 accumulated plasma potassium. Increased extr.cellular potassium causes changes in muscle

Real-time ultrasound imaging of irreversible electroporation in a porcine liver model adequately characterizes the zone of cellular necrosis.

PubMed

Schmidt, Carl R; Shires, Peter; Mootoo, Mary

2012-02-01

  Irreversible electroporation (IRE) is a largely non-thermal method for the ablation of solid tumours. The ability of ultrasound (US) to measure the size of the IRE ablation zone was studied in a porcine liver model.   Three normal pig livers were treated in vivo with a total of 22 ablations using IRE. Ultrasound was used within minutes after ablation and just prior to liver harvest at either 6 h or 24 h after the procedure. The area of cellular necrosis was measured after staining with nitroblue tetrazolium and the percentage of cell death determined by histomorphometry.   Visible changes in the hepatic parenchyma were apparent by US after all 22 ablations using IRE. The mean maximum diameter of the ablation zone measured by US during the procedure was 20.1 ± 2.7 mm. This compared with a mean cellular necrosis zone maximum diameter of 20.3 ± 2.9 mm as measured histologically. The mean percentage of dead cells within the ablation zone was 77% at 6 h and 98% at 24 h after ablation.   Ultrasound is a useful modality for measuring the ablation zone within minutes of applying IRE to normal liver tissue. The area of parenchymal change measured by US correlates with the area of cellular necrosis. © 2011 International Hepato-Pancreato-Biliary Association.

Cystic Fibrosis, Cystic Fibrosis Transmembrane Conductance Regulator and Drugs: Insights from Cellular Trafficking.

PubMed

Bridges, Robert J; Bradbury, Neil A

2018-01-01

The eukaryotic cell is organized into membrane-delineated compartments that are characterized by specific cadres of proteins sustaining biochemically distinct cellular processes. The appropriate subcellular localization of proteins is key to proper organelle function and provides a physiological context for cellular processes. Disruption of normal trafficking pathways for proteins is seen in several genetic diseases, where a protein's absence for a specific subcellular compartment leads to organelle disruption, and in the context of an individual, a disruption of normal physiology. Importantly, several drug therapies can also alter protein trafficking, causing unwanted side effects. Thus, a deeper understanding of trafficking pathways needs to be appreciated as novel therapeutic modalities are proposed. Despite the promising efficacy of novel therapeutic agents, the intracellular bioavailability of these compounds has proved to be a potential barrier, leading to failures in treatments for various diseases and disorders. While endocytosis of drug moieties provides an efficient means of getting material into cells, the subsequent release and endosomal escape of materials into the cytosol where they need to act has been a barrier. An understanding of cellular protein/lipid trafficking pathways has opened up strategies for increasing drug bioavailability. Approaches to enhance endosomal exit have greatly increased the cytosolic bioavailability of drugs and will provide a means of investigating previous drugs that may have been shelved due to their low cytosolic concentration.

Quantitative interactome reveals that porcine reproductive and respiratory syndrome virus nonstructural protein 2 forms a complex with viral nucleocapsid protein and cellular vimentin.

PubMed

Song, Tao; Fang, Liurong; Wang, Dang; Zhang, Ruoxi; Zeng, Songlin; An, Kang; Chen, Huanchun; Xiao, Shaobo

2016-06-16

Porcine reproductive and respiratory syndrome virus (PRRSV) is an Arterivirus that has heavily impacted the global swine industry. The PRRSV nonstructural protein 2 (nsp2) plays crucial roles in viral replication and host immune regulation, most likely by interacting with viral or cellular proteins that have not yet been identified. In this study, a quantitative interactome approach based on immunoprecipitation and stable isotope labeling with amino acids in cell culture (SILAC) was performed to identify nsp2-interacting proteins in PRRSV-infected cells with an nsp2-specific monoclonal antibody. Nine viral proteins and 62 cellular proteins were identified as potential nsp2-interacting partners. Our data demonstrate that the PRRSV nsp1α, nsp1β, and nucleocapsid proteins all interact directly with nsp2. Nsp2-interacting cellular proteins were classified into different functional groups and an interactome network of nsp2 was generated. Interestingly, cellular vimentin, a known receptor for PRRSV, forms a complex with nsp2 by using viral nucleocapsid protein as an intermediate. Taken together, the nsp2 interactome under the condition of virus infection clarifies a role of nsp2 in PRRSV replication and immune evasion. Viral proteins must interact with other virus-encoded proteins and/or host cellular proteins to function, and interactome analysis is an ideal approach for identifying such interacting proteins. In this study, we used the quantitative interactome methodology to identify the viral and cellular proteins that potentially interact with the nonstructural protein 2 (nsp2) of porcine reproductive and respiratory syndrome virus (PRRSV) under virus infection conditions, thus providing a rich source of potential viral and cellular interaction partners for PRRSV nsp2. Based on the interactome data, we further demonstrated that PRRSV nsp2 and nucleocapsid protein together with cellular vimentin, form a complex that may be essential for viral attachment and replication, which partly explains the role of nsp2 in PRRSV replication and immune evasion. Copyright © 2016 Elsevier B.V. All rights reserved.

A virocentric perspective on the evolution of life

PubMed Central

Koonin, Eugene V.; Dolja, Valerian V.

2015-01-01

Viruses and/or virus-like selfish elements are associated with all cellular life forms and are the most abundant biological entities on Earth, with the number of virus particles in many environments exceeding the number of cells by one to two orders of magnitude. The genetic diversity of viruses is commensurately enormous and might substantially exceed the diversity of cellular organisms. Unlike cellular organisms with their uniform replication-expression scheme, viruses possess either RNA or DNA genomes and exploit all conceivable replication-expression strategies. Although viruses extensively exchange genes with their hosts, there exists a set of viral hallmark genes that are shared by extremely diverse groups of viruses to the exclusion of cellular life forms. Coevolution of viruses and host defense systems is a key aspect in the evolution of both viruses and cells, and viral genes are often recruited for cellular functions. Together with the fundamental inevitability of the emergence of genomic parasites in any evolving replicator system, these multiple lines of evidence reveal the central role of viruses in the entire evolution of life. PMID:23850169

Inter-Cellular Exchange of Cellular Components via VE-Cadherin-Dependent Trans-Endocytosis

PubMed Central

Sakurai, Takashi; Woolls, Melissa J.; Jin, Suk-Won

2014-01-01

Cell-cell communications typically involve receptor-mediated signaling initiated by soluble or cell-bound ligands. Here, we report a unique mode of endocytosis: proteins originating from cell-cell junctions and cytosolic cellular components from the neighboring cell are internalized, leading to direct exchange of cellular components between two adjacent endothelial cells. VE-cadherins form transcellular bridges between two endothelial cells that are the basis of adherence junctions. At such adherens junction sites, we observed the movement of the entire VE-cadherin molecule from one endothelial cell into the other with junctional and cytoplasmic components. This phenomenon, here termed trans-endocytosis, requires the establishment of a VE-cadherin homodimer in trans with internalization proceeding in a Rac1-, and actomyosin-dependent manner. Importantly, the trans-endocytosis is not dependent on any known endocytic pathway including clathrin-dependent endocytosis, macropinocytosis or phagocytosis. This novel form of cell-cell communications, leading to a direct exchange of cellular components, was observed in 2D and 3D-cultured endothelial cells as well as in the developing zebrafish vasculature. PMID:24603875

Novel DNA lesions generated by the interaction between therapeutic thiopurines and UVA light.

PubMed

Zhang, Xiaohong; Jeffs, Graham; Ren, Xiaolin; O'Donovan, Peter; Montaner, Beatriz; Perrett, Conal M; Karran, Peter; Xu, Yao-Zhong

2007-03-01

The therapeutic effect of the thiopurines, 6-thioguanine (6-TG), 6-mercaptopurine, and its prodrug azathioprine, depends on the incorporation of 6-TG into cellular DNA. Unlike normal DNA bases, 6-TG absorbs UVA radiation, and UVA-mediated photochemical damage of DNA 6-TG has potentially harmful side effects. When free 6-TG is UVA irradiated in solution in the presence of molecular oxygen, reactive oxygen species are generated and 6-TG is oxidized to guanine-6-sulfonate (G(SO3)) and guanine-6-thioguanine in reactions involving singlet oxygen. This conversion is prevented by antioxidants, including the dietary vitamin ascorbate. DNA G(SO3) is also the major photoproduct of 6-TG in DNA and it can be selectively introduced into DNA or oligonucleotides in vitro by mild chemical oxidation. Thermal stability measurements indicate that G(SO3) does not form stable base pairs with any of the normal DNA bases in duplex oligonucleotides and is a powerful block for elongation by Klenow DNA polymerase in primer extension experiments. In cultured human cells, DNA damage produced by 6-TG and UVA treatment is associated with replication inhibition and provokes a p53-dependent DNA damage response.

Roles of specific membrane lipid domains in EGF receptor activation and cell adhesion molecule stabilization in a developing olfactory system.

PubMed

Gibson, Nicholas J; Tolbert, Leslie P; Oland, Lynne A

2009-09-29

Reciprocal interactions between glial cells and olfactory receptor neurons (ORNs) cause ORN axons entering the brain to sort, to fasciculate into bundles destined for specific glomeruli, and to form stable protoglomeruli in the developing olfactory system of an experimentally advantageous animal species, the moth Manduca sexta. Epidermal growth factor receptors (EGFRs) and the cell adhesion molecules (IgCAMs) neuroglian and fasciclin II are known to be important players in these processes. We report in situ and cell-culture studies that suggest a role for glycosphingolipid-rich membrane subdomains in neuron-glia interactions. Disruption of these subdomains by the use of methyl-beta-cyclodextrin results in loss of EGFR activation, depletion of fasciclin II in ORN axons, and loss of neuroglian stabilization in the membrane. At the cellular level, disruption leads to aberrant ORN axon trajectories, small antennal lobes, abnormal arrays of olfactory glomerul, and loss of normal glial cell migration. We propose that glycosphingolipid-rich membrane subdomains (possible membrane rafts or platforms) are essential for IgCAM-mediated EGFR activation and for anchoring of neuroglian to the cytoskeleton, both required for normal extension and sorting of ORN axons.

Contribution of arginase to manganese metabolism of Aspergillus niger.

PubMed

Keni, Sarita; Punekar, Narayan S

2016-02-01

Aspects of manganese metabolism during normal and acidogenic growth of Aspergillus niger were explored. Arginase from this fungus was a Mn[II]-enzyme. The contribution of the arginase protein towards A. niger manganese metabolism was investigated using arginase knockout (D-42) and arginase over-expressing (ΔXCA-29) strains of A. niger NCIM 565. The Mn[II] contents of various mycelial fractions were found in the order: D-42 strain < parent strain < ΔXCA-29 strain. While the soluble fraction forms 60% of the total mycelial Mn[II] content, arginase accounted for a significant fraction of this soluble Mn[II] pool. Changes in the arginase levels affected the absolute mycelial Mn[II] content but not its distribution in the various mycelial fractions. The A. niger mycelia harvested from acidogenic growth media contain substantially less Mn[II] as compared to those from normal growth media. Nevertheless, acidogenic mycelia harbor considerable Mn[II] levels and a functional arginase. Altered levels of mycelial arginase protein did not significantly influence citric acid production. The relevance of arginase to cellular Mn[II] pool and homeostasis was evaluated and the results suggest that arginase regulation could occur via manganese availability.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, W.H.; Adams, D.G.

Mice ingesting 30 to 50% D/sub 2/O (heavy water, deuterium oxide) developed a dose-dependent depression of formed peripheral blood elements in 4 to 9 days. The principal mechanism of anemia and thrombocytopenia is impaired hematopoiesis. Despite pancytopenia in the peripheral blood, bone marrow cellularity and morphology remained normal. Upon replacement of D/sub 2/O with tap water, platelet and neutrophil concentrations returned to normal within 48 to 72 hr. In contrast, blood lymphocyte concentrations remained low for several weeks. B-lymphocytes may be more affected by deuteration than other lymphocyte subsets. In vivo reticuloendothelial cell function, as assessed by /sup 51/Cr-labeled sheepmore » erythrocyte clearance, was unaffected by D/sub 2/O. Although a dose-dependent decrease in fluid intake occurred during deuteration, hematocytopenia was not a consequence of dehydration. In view of the known kinetics of D/sub 2/O in biological systems, the rapid response of myeloid elements to deuteration must be due primarily to the solvent (nonmetabolic) isotope effect. Prolonged deuteration has proven toxic when included in regimens for treatment of neoplasia, including leukemia, in animal models. The present study shows that modulation of hematopoiesis by D/sub 2/O is possible without invoking the toxicities associated with prolonged deuteration.« less

Delay and trace fear conditioning in C57BL/6 and DBA/2 mice: issues of measurement and performance.

PubMed

Tipps, Megan E; Raybuck, Jonathan D; Buck, Kari J; Lattal, K Matthew

2014-08-01

Strain comparison studies have been critical to the identification of novel genetic and molecular mechanisms in learning and memory. However, even within a single learning paradigm, the behavioral data for the same strain can vary greatly, making it difficult to form meaningful conclusions at both the behavioral and cellular level. In fear conditioning, there is a high level of variability across reports, especially regarding responses to the conditioned stimulus (CS). Here, we compare C57BL/6 and DBA/2 mice using delay fear conditioning, trace fear conditioning, and a nonassociative condition. Our data highlight both the significant strain differences apparent in these fear conditioning paradigms and the significant differences in conditioning type within each strain. We then compare our data to an extensive literature review of delay and trace fear conditioning in these two strains. Finally, we apply a number of commonly used baseline normalization approaches to compare how they alter the reported differences. Our findings highlight three major sources of variability in the fear conditioning literature: CS duration, number of CS presentations, and data normalization to baseline measures. © 2014 Tipps et al.; Published by Cold Spring Harbor Laboratory Press.

Clinical, cellular, microscopic, and ultrastructural studies of a case of fibrogenesis imperfecta ossium

PubMed Central

Barron, Melissa L; Rybchyn, Mark S; Ramesh, Sutharshani; Mason, Rebecca S; Fiona Bonar, S; Stalley, Paul; Khosla, Sundeep; Hudson, Bernie; Arthur, Christopher; Kim, Edward; Clifton-Bligh, Roderick J; Clifton-Bligh, Phillip B

2017-01-01

Fibrogenesis imperfecta ossium is a rare disorder of bone usually characterized by marked osteopenia and associated with variable osteoporosis and osteosclerosis, changing over time. Histological examination shows that newly formed collagen is abnormal, lacking birefringence when examined by polarized light. The case presented demonstrates these features and, in addition, a previously undocumented finding of a persistent marked reduction of the serum C3 and C4. Osteoblasts established in culture from a bone biopsy showed abnormal morphology on electron microscopy and increased proliferation when cultured with benzoylbenzoyl-ATP and 1,25-dihydroxyvitamin D, contrasting with findings in normal osteoblasts in culture. A gene microarray study showed marked upregulation of the messenger RNA (mRNA) for G-protein-coupled receptor 128 (GPR 128), an orphan receptor of unknown function and also of osteoprotegerin in the patient’s osteoblasts in culture. When normal osteoblasts were cultured with the patient’s serum, there was marked upregulation of the mRNA for aquaporin 1. A single pathogenetic factor to account for the features of this disorder has not been defined, but the unique findings described here may facilitate more definitive investigation of the abnormal bone cell function. PMID:28326223

Synthetic physical interactions map kinetochore regulators and regions sensitive to constitutive Cdc14 localization.

PubMed

Ólafsson, Guðjón; Thorpe, Peter H

2015-08-18

The location of proteins within eukaryotic cells is often critical for their function and relocation of proteins forms the mainstay of regulatory pathways. To assess the importance of protein location to cellular homeostasis, we have developed a methodology to systematically create binary physical interactions between a query protein and most other members of the proteome. This method allows us to rapidly assess which of the thousands of possible protein interactions modify a phenotype. As proof of principle we studied the kinetochore, a multiprotein assembly that links centromeres to the microtubules of the spindle during cell division. In budding yeast, the kinetochores from the 16 chromosomes cluster together to a single location within the nucleus. The many proteins that make up the kinetochore are regulated through ubiquitylation and phosphorylation. By systematically associating members of the proteome to the kinetochore, we determine which fusions affect its normal function. We identify a number of candidate kinetochore regulators, including the phosphatase Cdc14. We examine where within the kinetochore Cdc14 can act and show that the effect is limited to regions that correlate with known phosphorylation sites, demonstrating the importance of serine phospho-regulation for normal kinetochore homeostasis.

VOLTAGE-GATED POTASSIUM CHANNELS AT THE CROSSROADS OF NEURONAL FUNCTION, ISCHEMIC TOLERANCE, AND NEURODEGENERATION

PubMed Central

Shah, Niyathi Hegde; Aizenman, Elias

2013-01-01

Voltage-gated potassium (Kv) channels are widely expressed in the central and peripheral nervous system, and are crucial mediators of neuronal excitability. Importantly, these channels also actively participate in cellular and molecular signaling pathways that regulate the life and death of neurons. Injury-mediated increased K+ efflux through Kv2.1 channels promotes neuronal apoptosis, contributing to widespread neuronal loss in neurodegenerative disorders such as Alzheimer’s disease and stroke. In contrast, some forms of neuronal activity can dramatically alter Kv2.1 channel phosphorylation levels and influence their localization. These changes are normally accompanied by modifications in channel voltage-dependence, which may be neuroprotective within the context of ischemic injury. Kv1 and Kv7 channel dysfunction leads to neuronal hyperexcitability that critically contributes to the pathophysiology of human clinical disorders such as episodic ataxia and epilepsy. This review summarizes the neurotoxic, neuroprotective, and neuroregulatory roles of Kv channels, and highlights the consequences of Kv channel dysfunction on neuronal physiology. The studies described in this review thus underscore the importance of normal Kv channel function in neurons, and emphasize the therapeutic potential of targeting Kv channels in the treatment of a wide range of neurological diseases. PMID:24323720

Design and testing of botanical thermotropic actuator mechanisms in thermally adaptive building coverings

NASA Astrophysics Data System (ADS)

Barrett, Ronald M.; Barrett, Ronald P.; Barrett, Cassandra M.

2017-09-01

This paper lays out the inspiration, operational principles, analytical modeling and coupon testing of a new class of thermally adaptive building coverings. The fundamental driving concepts for these coverings are derived from various families of thermotropic plant structures. Certain plant cellular structures like those in Mimosa pudica (Sensitive Plant), Rhododendron leaves or Albizia julibrissin (Mimosa Tree), exhibit actuation physiology which depends on changes in cellular turgor pressures to generate motion. This form of cellular action via turgor pressure manipulation is an inspiration for a new field of thermally adaptive building coverings which use various forms of cellular foam to aid or enable actuation much like plant cells are used to move leaves. When exposed to high solar loading, the structures use the inherent actuation capability of pockets of air trapped in closed cell foam as actuators to curve plates upwards and outwards. When cold, these same structures curve back towards the building forming large convex pockets of dead air to insulate the building. This paper describes basic classical laminated plate theory models comparing theory and experiment of such coupons containing closed-cell foam actuators. The study concludes with a global description of the effectiveness of this class of thermally adaptive building coverings.

Multicellular regulation of entropy, spatial order, and information

NASA Astrophysics Data System (ADS)

Youk, Hyun

Many multicellular systems such as tissues and microbial biofilms consist of cells that secrete and sense signalling molecules. Understanding how collective behaviours of secrete-and-sense cells is an important challenge. We combined experimental and theoretical approaches to understand multicellular coordination of gene expression and spatial pattern formation among secrete-and-sense cells. We engineered secrete-and-sense yeast cells to show that cells can collectively and permanently remember a past event by reminding each other with their secreted signalling molecule. If one cell ``forgets'' then another cell can remind it. Cell-cell communication ensures a long-term (permanent) memory by overcoming common limitations of intracellular memory. We also established a new theoretical framework inspired by statistical mechanics to understand how fields of secrete-and-sense cells form spatial patterns. We introduce new metrics - cellular entropy, cellular Hamiltonian, and spatial order index - for dynamics of cellular automata that form spatial patterns. Our theory predicts how fast any spatial patterns form, how ordered they are, and establishes cellular Hamiltonian that, like energy for non-living systems, monotonically decreases towards a minimum over time. ERC Starting Grant (MultiCellSysBio), NWO VIDI, NWO NanoFront.

Quantitative Biology of Exercise-Induced Signal Transduction Pathways.

PubMed

Liu, Timon Cheng-Yi; Liu, Gang; Hu, Shao-Juan; Zhu, Ling; Yang, Xiang-Bo; Zhang, Quan-Guang

2017-01-01

Exercise is essential in regulating energy metabolism. Exercise activates cellular, molecular, and biochemical pathways with regulatory roles in training response adaptation. Among them, endurance/strength training of an individual has been shown to activate its respective signal transduction pathways in skeletal muscle. This was further studied from the viewpoint of quantitative difference (QD). For the mean values, [Formula: see text], of two sets of data, their QD is defined as [Formula: see text] ([Formula: see text]). The function-specific homeostasis (FSH) of a function of a biosystem is a negative-feedback response of the biosystem to maintain the function-specific conditions inside the biosystem so that the function is perfectly performed. A function in/far from its FSH is called a normal/dysfunctional function. A cellular normal function can resist the activation of other signal transduction pathways so that there are normal function-specific signal transduction pathways which full activation maintains the normal function. An acute endurance/strength training may be dysfunctional, but its regular training may be normal. The normal endurance/strength training of an individual may resist the activation of other signal transduction pathways in skeletal muscle so that there may be normal endurance/strength training-specific signal transduction pathways (NEPs/NSPs) in skeletal muscle. The endurance/strength training may activate NSPs/NEPs, but the QD from the control is smaller than 0.80. The simultaneous activation of both NSPs and NEPs may enhance their respective activation, and the QD from the control is larger than 0.80. The low level laser irradiation pretreatment of rats may promote the activation of NSPs in endurance training skeletal muscle. There may be NEPs/NSPs in skeletal muscle trained by normal endurance/strength training.

Quantitative analysis of cellular glutathione by flow cytometry utilizing monochlorobimane: some applications to radiation and drug resistance in vitro and in vivo.

PubMed

Rice, G C; Bump, E A; Shrieve, D C; Lee, W; Kovacs, M

1986-12-01

An assay using a bimane derivative has been developed to detect free glutathione (GSH) in individual viable cells by flow cytometry. Monochlorobimane [syn-(ClCH2CH3)-1,5-diazabicycla[3.30]acta-3,6-diene-2,8-dio ne], itself nonfluorescent, reacts with GSH to form a highly fluorescent derivative. High pressure liquid chromatography analysis showed that, using specific staining conditions, the only low molecular weight fluorescent derivative formed in Chinese hamster ovary cells was that formed with GSH. Very little reaction with protein sulfhydryls was observed. Rates of GSH depletion in Chinese hamster ovary cells exposed to diethylmaleate were essentially the same, whether measured by relative fluorescence intensity, by flow cytometry or by enzymatic assay on cellular extracts. This method was shown to be useful for measurement of GSH resynthesis, uptake, and depletion by prolonged hypoxia and misonidazole treatment. Since measurements are made on individual cells, cell-to-cell variation and populational heterogeneity in GSH content are revealed by flow cytometry. Although under most conditions in vitro GSH content is relatively homogeneous, under certain circumstances, such as release from hypoxia, heterogeneity in populational GSH levels was observed. The significance of this heterogeneity is discussed in regard to the induction of gene amplification and drug resistance by transient hypoxia. Numerous subclones of Chinese hamster ovary cells selected by growth in Adriamycin or methotrexate-containing medium express elevated levels of GSH per cell. The method was extended to quantitate the GSH content of cells excised from EMT-6/SF mouse tumors that had been treated in vivo with L-buthionine-S-R-sulfoximine, an inhibitor of GSH synthesis. The bivariate analysis (forward angle light scatter versus monochlorobimane fluorescence) of cells derived from these tumors gave excellent resolution of normal and tumor cells and demonstrated extensive heterogeneity in the tumor cell population with respect to GSH content per cell.

Cellular automatons applied to gas dynamic problems

NASA Technical Reports Server (NTRS)

Long, Lyle N.; Coopersmith, Robert M.; Mclachlan, B. G.

1987-01-01

This paper compares the results of a relatively new computational fluid dynamics method, cellular automatons, with experimental data and analytical results. This technique has been shown to qualitatively predict fluidlike behavior; however, there have been few published comparisons with experiment or other theories. Comparisons are made for a one-dimensional supersonic piston problem, Stokes first problem, and the flow past a normal flat plate. These comparisons are used to assess the ability of the method to accurately model fluid dynamic behavior and to point out its limitations. Reasonable results were obtained for all three test cases, but the fundamental limitations of cellular automatons are numerous. It may be misleading, at this time, to say that cellular automatons are a computationally efficient technique. Other methods, based on continuum or kinetic theory, would also be very efficient if as little of the physics were included.

Investigating cellular network heterogeneity and modularity in cancer: a network entropy and unbalanced motif approach.

PubMed

Cheng, Feixiong; Liu, Chuang; Shen, Bairong; Zhao, Zhongming

2016-08-26

Cancer is increasingly recognized as a cellular system phenomenon that is attributed to the accumulation of genetic or epigenetic alterations leading to the perturbation of the molecular network architecture. Elucidation of network properties that can characterize tumor initiation and progression, or pinpoint the molecular targets related to the drug sensitivity or resistance, is therefore of critical importance for providing systems-level insights into tumorigenesis and clinical outcome in the molecularly targeted cancer therapy. In this study, we developed a network-based framework to quantitatively examine cellular network heterogeneity and modularity in cancer. Specifically, we constructed gene co-expressed protein interaction networks derived from large-scale RNA-Seq data across 8 cancer types generated in The Cancer Genome Atlas (TCGA) project. We performed gene network entropy and balanced versus unbalanced motif analysis to investigate cellular network heterogeneity and modularity in tumor versus normal tissues, different stages of progression, and drug resistant versus sensitive cancer cell lines. We found that tumorigenesis could be characterized by a significant increase of gene network entropy in all of the 8 cancer types. The ratio of the balanced motifs in normal tissues is higher than that of tumors, while the ratio of unbalanced motifs in tumors is higher than that of normal tissues in all of the 8 cancer types. Furthermore, we showed that network entropy could be used to characterize tumor progression and anticancer drug responses. For example, we found that kinase inhibitor resistant cancer cell lines had higher entropy compared to that of sensitive cell lines using the integrative analysis of microarray gene expression and drug pharmacological data collected from the Genomics of Drug Sensitivity in Cancer database. In addition, we provided potential network-level evidence that smoking might increase cancer cellular network heterogeneity and further contribute to tyrosine kinase inhibitor (e.g., gefitinib) resistance. In summary, we demonstrated that network properties such as network entropy and unbalanced motifs associated with tumor initiation, progression, and anticancer drug responses, suggesting new potential network-based prognostic and predictive measure in cancer.

Endocytoscopic findings of lymphomas of the stomach.

PubMed

Isomoto, Hajime; Matsushima, Kayoko; Hayashi, Tomayoshi; Imaizumi, Yoshitaka; Shiota, Junya; Ishii, Hiroyuki; Minami, Hitomi; Ohnita, Ken; Takeshima, Fuminao; Shikuwa, Saburo; Miyazaki, Yasushi; Nakao, Kazuhiko

2013-12-26

The gastric lesions of various lymphomas were observed at the cellular level using endocytoscopy. Endocytoscopy and magnifying endoscopy with narrow band imaging (NBI) were performed in 17 patients with lymphomas of the stomach. The lesions consisted of 7 with low-grade mucosa-associated lymphoid tissue (MALT), 5 with gastric involvement by adult T-cell leukemia/lymphoma (ATLL), 4 with diffuse large B-cell lymphoma (DLBCL), and 1 with peripheral T-cell lymphoma. On conventional endoscopy, 9 were classified as having superficial spreading type, 7 were mass-forming type, and 1 was diffuse infiltrating type. Anti-H. pylori treatment was given in the 7 MALT lymphoma cases. NBI magnification endoscopy invariably showed dilatation or ballooning and destruction of gastric pits and elongation and distortion in microvessels. Endocytoscopy showed mucosal aggregation of interstitial cellular elements in almost all gastric lymphoma cases. The nuclear diversity in size and configuration was exclusively seen in gastric lymphomas other than MALT lymphoma, whereas the nuclei of MALT lymphoma cells were regular and small to moderate in size. Inter-glandular infiltration by lymphomatous cell elements was frequently observed in MALT lymphoma and DLBCL, but it was uncommon in peripheral gastric T-cell malignancies. Endocytoscopy could identify the disease-specific histology, the lymphoepithelial origin, as inter-glandular infiltration of cellular components in MALT lymphoma and the possibly related DLBCL cases. Complete regression (CR) was observed in 2 of the 7 MALT lymphoma patients. In the 2 patients with CR who underwent repeat endocytoscopy, the ultra-high magnification abnormalities returned to normal, while they were unchanged in those without tumor regression. On endocytoscopy, intra-glandular aggregation of cellular components was invariably identified in lymphomas of the stomach. Nuclear regularity in size and configuration may indicate the cytological grade, differentiating the indolent low-grade from aggressive lymphoproliferative diseases. The inter-glandular infiltration seen on endocytoscopy can indicate the lymphoepithelial lesions seen in MALT lymphoma and related DLBCL. Endocytoscopy would be applicable for virtual histopathological diagnosis of different lymphoproliferative disorders and their clinical assessment during ongoing endoscopy.

Cellular Immune Response to Cytomegalovirus Infection After Renal Transplantation

PubMed Central

Linnemann, Calvin C.; Kauffman, Carol A.; First, M. Roy; Schiff, Gilbert M.; Phair, John P.

1978-01-01

A prospective study of 15 patients who received renal transplants defined the effect of renal transplantation on the cellular immune response to cytomegalovirus infection. Of 15 patients, 14 developed cytomegalovirus infection, usually in the first 2 months after transplantation, and all infections were accompanied by a normal humoral immune response. After the initiation of immunosuppressive therapy and transplantation, there was a general depression of lymphocyte transformation, as reflected in the response to phytohemagglutinin, accompanied by a specific defect in cellular immunity, as indicated by lymphocyte transformation to cytomegalovirus antigen. Eleven patients had cellular immunity to cytomegalovirus before transplantation, and all of these became negative in the first month after transplantation. In subsequent months, only 6 of the 14 study patients with cytomegalovirus infection developed specific cellular immune responses to cytomegalovirus. This occurred most often in patients who had severe febrile illnesses in association with infection. The specific cellular immune response which developed in the posttransplant period did not persist in three of the patients. This study demonstrates the dissociation of the humoral and cellular immune response to cytomegalovirus infection in renal transplant patients and indicates the importance of the loss of cellular immunity in the appearance of infection. Previously infected patients lost their cell-mediated immunity and had reactivation infections despite the presence of serum antibody. PMID:215541

The scent fingerprint of hepatocarcinoma: in-vitro metastasis prediction with volatile organic compounds (VOCs)

PubMed Central

Amal, Haitham; Ding, Lu; Liu, Bin-bin; Tisch, Ulrike; Xu, Zhen-qin; Shi, Da-you; Zhao, Yan; Chen, Jie; Sun, Rui-xia; Liu, Hu; Ye, Sheng-Long; Tang, Zhao-you; Haick, Hossam

2012-01-01

Background: Hepatocellular carcinoma (HCC) is a common and aggressive form of cancer. Due to a high rate of postoperative recurrence, the prognosis for HCC is poor. Subclinical metastasis is the major cause of tumor recurrence and patient mortality. Currently, there is no reliable prognostic method of invasion. Aim: To investigate the feasibility of fingerprints of volatile organic compounds (VOCs) for the in-vitro prediction of metastasis. Methods: Headspace gases were collected from 36 cell cultures (HCC with high and low metastatic potential and normal cells) and analyzed using nanomaterial-based sensors. Predictive models were built by employing discriminant factor analysis pattern recognition, and the classification success was determined using leave-one-out cross-validation. The chemical composition of each headspace sample was studied using gas chromatography coupled with mass spectrometry (GC-MS). Results: Excellent discrimination was achieved using the nanomaterial-based sensors between (i) all HCC and normal controls; (ii) low metastatic HCC and normal controls; (iii) high metastatic HCC and normal controls; and (iv) high and low HCC. Several HCC-related VOCs that could be associated with biochemical cellular processes were identified through GC-MS analysis. Conclusion: The presented results constitute a proof-of-concept for the in-vitro prediction of the metastatic potential of HCC from VOC fingerprints using nanotechnology. Further studies on a larger number of more diverse cell cultures are needed to evaluate the robustness of the VOC patterns. These findings could benefit the development of a fast and potentially inexpensive laboratory test for subclinical HCC metastasis. PMID:22888249

Cellular interface morphologies in directional solidification. II - The effect of grain boundaries

NASA Technical Reports Server (NTRS)

Ungar, Lyle H.; Brown, Robert A.

1984-01-01

A singular perturbation analysis valid for small grain-boundary slopes is used with the one-sided model for solidification to show that grain boundaries introduce imperfections into the symmetry of the developing cellular interfaces which rupture the junction between the family of planar shapes and the bifurcating cellular families. Undulating interfaces are shown to develop first near grain boundaries, and to evolve with decreasing temperature gradient either by a smooth transition from the almost planar family or by a sudden jump to moderate-amplitude cellular forms, depending on the growth rate.

Distinct 3' UTRs regulate the life-cycle-specific expression of two TCTP paralogs in Trypanosoma brucei.

PubMed

Jojic, Borka; Amodeo, Simona; Bregy, Irina; Ochsenreiter, Torsten

2018-05-10

The translationally controlled tumor protein (TCTP; also known as TPT1 in mammals) is highly conserved and ubiquitously expressed in eukaryotes. It is involved in growth and development, cell cycle progression, protection against cellular stresses and apoptosis, indicating the multifunctional role of the protein. Here, for the first time, we characterize the expression and function of TCTP in the human and animal pathogen, Trypanosoma brucei We identified two paralogs ( TCTP1 and TCTP2 ) that are differentially expressed in the life cycle of the parasite. The genes have identical 5' untranslated regions (UTRs) and almost identical open-reading frames. The 3'UTRs differ substantially in sequence and length, and are sufficient for the exclusive expression of TCTP1 in procyclic- and TCTP2 in bloodstream-form parasites. Furthermore, we characterize which parts of the 3'UTR are needed for TCTP2 mRNA stability. RNAi experiments demonstrate that TCTP1 and TCTP2 expression is essential for normal cell growth in procyclic- and bloodstream-form parasites, respectively. Depletion of TCTP1 in the procyclic form cells leads to aberrant cell and mitochondrial organelle morphology, as well as enlarged, and a reduced number of, acidocalcisomes. © 2018. Published by The Company of Biologists Ltd.

Reducing radiation-induced gastrointestinal toxicity — the role of the PHD/HIF axis

PubMed Central

Olcina, Monica M.; Giaccia, Amato J.

2016-01-01

Radiotherapy is an effective treatment strategy for cancer, but a significant proportion of patients experience radiation-induced toxicity due to damage to normal tissue in the irradiation field. The use of chemical or biological approaches aimed at reducing or preventing normal tissue toxicity induced by radiotherapy is a long-held goal. Hypoxia-inducible factors (HIFs) regulate the production of factors that may protect several cellular compartments affected by radiation-induced toxicity. Pharmacological inhibitors of prolyl hydroxylase domain–containing enzymes (PHDs), which result in stabilization of HIFs, have recently been proposed as a new class of radioprotectors. In this review, radiation-induced toxicity in the gastrointestinal (GI) tract and the main cellular compartments studied in this context will be discussed. The effects of PHD inhibition on GI radioprotection will be described in detail. PMID:27548524

PNUTS functions as a proto-oncogene by sequestering PTEN

PubMed Central

Kavela, Sridhar; Shinde, Swapnil R; Ratheesh, Raman; Viswakalyan, Kotapalli; Bashyam, Murali D; Gowrishankar, Swarnalata; Vamsy, Mohana; Pattnaik, Sujit; Rao, Subramanyeshwar; Sastry, Regulagadda A; Srinivasulu, Mukta; Chen, Junjie; Maddika, Subbareddy

2012-01-01

PTEN is a well-defined tumor suppressor gene that antagonizes the PI3K/Akt pathway to regulate a multitude of cellular processes such as survival, growth, motility, invasiveness and angiogenesis. While the functions of PTEN have been studied extensively, the regulation of its activity during normal and disease conditions still remains incompletely understood. In this study, we identified the protein phosphatase-1 nuclear targeting subunit PNUTS (PPP1R10) as a PTEN associated protein. PNUTS directly interacted with the lipid-binding domain (C2 domain) of PTEN and sequestered it in the nucleus. Depletion of PNUTS leads to increased apoptosis and reduced cellular proliferation in a PTEN-dependent manner. PNUTS expression was elevated in certain cancers compared to matched normal tissues. Collectively, our studies reveal PNUTS as a novel PTEN regulator and a likely oncogene. PMID:23117887

Cellular and ultrastructural characterization of the grey-morph phenotype in southern right whales (Eubalaena australis)

PubMed Central

Eroh, Guy D.; Clayton, Fred C.; Florell, Scott R.; Cassidy, Pamela B.; Chirife, Andrea; Marón, Carina F.; Valenzuela, Luciano O.; Campbell, Michael S.; Seger, Jon; Rowntree, Victoria J.; Leachman, Sancy A.

2017-01-01

Southern right whales (SRWs, Eubalena australis) are polymorphic for an X-linked pigmentation pattern known as grey morphism. Most SRWs have completely black skin with white patches on their bellies and occasionally on their backs; these patches remain white as the whale ages. Grey morphs (previously referred to as partial albinos) appear mostly white at birth, with a splattering of rounded black marks; but as the whales age, the white skin gradually changes to a brownish grey color. The cellular and developmental bases of grey morphism are not understood. Here we describe cellular and ultrastructural features of grey-morph skin in relation to that of normal, wild-type skin. Melanocytes were identified histologically and counted, and melanosomes were measured using transmission electron microscopy. Grey-morph skin had fewer melanocytes when compared to wild-type skin, suggesting reduced melanocyte survival, migration, or proliferation in these whales. Grey-morph melanocytes had smaller melanosomes relative to wild-type skin, normal transport of melanosomes to surrounding keratinocytes, and normal localization of melanin granules above the keratinocyte nuclei. These findings indicate that SRW grey-morph pigmentation patterns are caused by reduced numbers of melanocytes in the skin, as well as by reduced amounts of melanin production and/or reduced sizes of mature melanosomes. Grey morphism is distinct from piebaldism and albinism found in other species, which are genetic pigmentation conditions resulting from the local absence of melanocytes, or the inability to synthesize melanin, respectively. PMID:28170433

YB-1 Is Important for Late-Stage Embryonic Development, Optimal Cellular Stress Responses, and the Prevention of Premature Senescence

PubMed Central

Lu, Zhi Hong; Books, Jason T.; Ley, Timothy J.

2005-01-01

Proteins containing “cold shock” domains belong to the most evolutionarily conserved family of nucleic acid-binding proteins known among bacteria, plants, and animals. One of these proteins, YB-1, is widely expressed throughout development and has been implicated as a cell survival factor that regulates the transcription and/or translation of many cellular growth and death-related genes. For these reasons, YB-1 deficiency has been predicted to be incompatible with cell survival. However, the majority of YB-1−/− embryos develop normally up to embryonic day 13.5 (E13.5). After E13.5, YB-1−/− embryos exhibit severe growth retardation and progressive mortality, revealing a nonredundant role of YB-1 in late embryonic development. Fibroblasts derived from YB-1−/− embryos displayed a normal rate of protein synthesis and minimal alterations in the transcriptome and proteome but demonstrated reduced abilities to respond to oxidative, genotoxic, and oncogene-induced stresses. YB-1−/− cells under oxidative stress expressed high levels of the G1-specific CDK inhibitors p16Ink4a and p21Cip1 and senesced prematurely; this defect was corrected by knocking down CDK inhibitor levels with specific small interfering RNAs. These data suggest that YB-1 normally represses the transcription of CDK inhibitors, making it an important component of the cellular stress response signaling pathway. PMID:15899865

Cellular and ultrastructural characterization of the grey-morph phenotype in southern right whales (Eubalaena australis).

PubMed

Eroh, Guy D; Clayton, Fred C; Florell, Scott R; Cassidy, Pamela B; Chirife, Andrea; Marón, Carina F; Valenzuela, Luciano O; Campbell, Michael S; Seger, Jon; Rowntree, Victoria J; Leachman, Sancy A

2017-01-01

Southern right whales (SRWs, Eubalena australis) are polymorphic for an X-linked pigmentation pattern known as grey morphism. Most SRWs have completely black skin with white patches on their bellies and occasionally on their backs; these patches remain white as the whale ages. Grey morphs (previously referred to as partial albinos) appear mostly white at birth, with a splattering of rounded black marks; but as the whales age, the white skin gradually changes to a brownish grey color. The cellular and developmental bases of grey morphism are not understood. Here we describe cellular and ultrastructural features of grey-morph skin in relation to that of normal, wild-type skin. Melanocytes were identified histologically and counted, and melanosomes were measured using transmission electron microscopy. Grey-morph skin had fewer melanocytes when compared to wild-type skin, suggesting reduced melanocyte survival, migration, or proliferation in these whales. Grey-morph melanocytes had smaller melanosomes relative to wild-type skin, normal transport of melanosomes to surrounding keratinocytes, and normal localization of melanin granules above the keratinocyte nuclei. These findings indicate that SRW grey-morph pigmentation patterns are caused by reduced numbers of melanocytes in the skin, as well as by reduced amounts of melanin production and/or reduced sizes of mature melanosomes. Grey morphism is distinct from piebaldism and albinism found in other species, which are genetic pigmentation conditions resulting from the local absence of melanocytes, or the inability to synthesize melanin, respectively.

Flow cytometric measurement of total DNA and incorporated halodeoxyuridine

DOEpatents

Dolbeare, F.A.; Gray, J.W.

1983-10-18

A method for the simultaneous flow cylometric measurement of total cellular DNA content and of the uptake of DNA precursors as a measure of DNA synthesis during various phases of the cell cycle in normal and malignant cells in vitro and in vivo is described. The method comprises reacting cells with labelled halodeoxyuridine (HdU), partially denaturing cellular DNA, adding to the reaction medium monoclonal antibodies (mabs) reactive with HdU, reacting the bound mabs with a second labelled antibody, incubating the mixture with a DNA stain, and measuring simultaneously the intensity of the DNA stain as a measure of the total cellular DNA and the HdU incorporated as a measure of DNA synthesis. (ACR)

Redox signaling in pathophysiology of hypertension.

PubMed

Majzunova, Miroslava; Dovinova, Ima; Barancik, Miroslav; Chan, Julie Y H

2013-09-18

Reactive oxygen species (ROS) are products of normal cellular metabolism and derive from various sources in different cellular compartments. Oxidative stress resultant from imbalance between ROS generation and antioxidant defense mechanisms is important in pathogenesis of cardiovascular diseases, such as hypertension, heart failure, atherosclerosis, diabetes, and cardiac hypertrophy. In this review we focus on hypertension and address sources of cellular ROS generation, mechanisms involved in regulation of radical homeostasis, superoxide dismutase isoforms in pathophysiology of hypertension; as well as radical intracellular signaling and phosphorylation processes in proteins of the affected cardiovascular tissues. Finally, we discuss the transcriptional factors involved in redox-sensitive gene transcription and antioxidant response, as well as their roles in hypertension.

Redox signaling in pathophysiology of hypertension

PubMed Central

2013-01-01

Reactive oxygen species (ROS) are products of normal cellular metabolism and derive from various sources in different cellular compartments. Oxidative stress resultant from imbalance between ROS generation and antioxidant defense mechanisms is important in pathogenesis of cardiovascular diseases, such as hypertension, heart failure, atherosclerosis, diabetes, and cardiac hypertrophy. In this review we focus on hypertension and address sources of cellular ROS generation, mechanisms involved in regulation of radical homeostasis, superoxide dismutase isoforms in pathophysiology of hypertension; as well as radical intracellular signaling and phosphorylation processes in proteins of the affected cardiovascular tissues. Finally, we discuss the transcriptional factors involved in redox-sensitive gene transcription and antioxidant response, as well as their roles in hypertension. PMID:24047403

Estrogen-Related Receptor α (ERRα) and ERRγ Are Essential Coordinators of Cardiac Metabolism and Function

PubMed Central

Wang, Ting; McDonald, Caitlin; Petrenko, Nataliya B.; Leblanc, Mathias; Wang, Tao; Giguere, Vincent; Evans, Ronald M.; Patel, Vickas V.

2015-01-01

Almost all cellular functions are powered by a continuous energy supply derived from cellular metabolism. However, it is little understood how cellular energy production is coordinated with diverse energy-consuming cellular functions. Here, using the cardiac muscle system, we demonstrate that nuclear receptors estrogen-related receptor α (ERRα) and ERRγ are essential transcriptional coordinators of cardiac energy production and consumption. On the one hand, ERRα and ERRγ together are vital for intact cardiomyocyte metabolism by directly controlling expression of genes important for mitochondrial functions and dynamics. On the other hand, ERRα and ERRγ influence major cardiomyocyte energy consumption functions through direct transcriptional regulation of key contraction, calcium homeostasis, and conduction genes. Mice lacking both ERRα and cardiac ERRγ develop severe bradycardia, lethal cardiomyopathy, and heart failure featuring metabolic, contractile, and conduction dysfunctions. These results illustrate that the ERR transcriptional pathway is essential to couple cellular energy metabolism with energy consumption processes in order to maintain normal cardiac function. PMID:25624346

Regulation of cell function by methionine oxidation and reduction

PubMed Central

Hoshi, Toshinori; Heinemann, Stefan H

2001-01-01

Reactive oxygen species (ROS) are generated during normal cellular activity and may exist in excess in some pathophysiological conditions, such as inflammation or reperfusion injury. These molecules oxidize a variety of cellular constituents, but sulfur-containing amino acid residues are especially susceptible. While reversible cysteine oxidation and reduction is part of well-established signalling systems, the oxidation and the enzymatically catalysed reduction of methionine is just emerging as a novel molecular mechanism for cellular regulation. Here we discuss how the oxidation of methionine to methionine sulfoxide in signalling proteins such as ion channels affects the function of these target proteins. Methionine sulfoxide reductase, which reduces methionine sulfoxide to methionine in a thioredoxin-dependent manner, is therefore not only an enzyme important for the repair of age- or degenerative disease-related protein modifications. It is also a potential missing link in the post-translational modification cycle involved in the specific oxidation and reduction of methionine residues in cellular signalling proteins, which may give rise to activity-dependent plastic changes in cellular excitability. PMID:11179387

Laboratory and clinical studies of cancer chemoprevention by antioxidants in berries.

PubMed

Stoner, Gary David; Wang, Li-Shu; Casto, Bruce Cordell

2008-09-01

Reactive oxygen species (ROS) are a major cause of cellular injury in an increasing number of diseases, including cancer. Most ROS are created in the cell through normal cellular metabolism. They can be produced by environmental insults such as ultraviolet light and toxic chemicals, as well as by the inflammatory process. Interception of ROS or limiting their cellular effects is a major role of antioxidants. Due to their content of phenolic and flavonoid compounds, berries exhibit high antioxidant potential, exceeding that of many other foodstuffs. Through their ability to scavenge ROS and reduce oxidative DNA damage, stimulate antioxidant enzymes, inhibit carcinogen-induced DNA adduct formation and enhance DNA repair, berry compounds have been shown to inhibit mutagenesis and cancer initiation. Berry constituents also influence cellular processes associated with cancer progression including signaling pathways associated with cell proliferation, differentiation, apoptosis and angiogenesis. This review article summarizes laboratory and human studies, demonstrating the protective effects of berries and berry constituents on oxidative and other cellular processes leading to cancer development.

Laboratory and clinical studies of cancer chemoprevention by antioxidants in berries

PubMed Central

Stoner, Gary David; Wang, Li-Shu; Casto, Bruce Cordell

2008-01-01

Reactive oxygen species (ROS) are a major cause of cellular injury in an increasing number of diseases, including cancer. Most ROS are created in the cell through normal cellular metabolism. They can be produced by environmental insults such as ultraviolet light and toxic chemicals, as well as by the inflammatory process. Interception of ROS or limiting their cellular effects is a major role of antioxidants. Due to their content of phenolic and flavonoid compounds, berries exhibit high antioxidant potential, exceeding that of many other foodstuffs. Through their ability to scavenge ROS and reduce oxidative DNA damage, stimulate antioxidant enzymes, inhibit carcinogen-induced DNA adduct formation and enhance DNA repair, berry compounds have been shown to inhibit mutagenesis and cancer initiation. Berry constituents also influence cellular processes associated with cancer progression including signaling pathways associated with cell proliferation, differentiation, apoptosis and angiogenesis. This review article summarizes laboratory and human studies, demonstrating the protective effects of berries and berry constituents on oxidative and other cellular processes leading to cancer development. PMID:18544560

SPED light sheet microscopy: fast mapping of biological system structure and function

PubMed Central

Tomer, Raju; Lovett-Barron, Matthew; Kauvar, Isaac; Andalman, Aaron; Burns, Vanessa M.; Sankaran, Sethuraman; Grosenick, Logan; Broxton, Michael; Yang, Samuel; Deisseroth, Karl

2016-01-01

The goal of understanding living nervous systems has driven interest in high-speed and large field-of-view volumetric imaging at cellular resolution. Light-sheet microscopy approaches have emerged for cellular-resolution functional brain imaging in small organisms such as larval zebrafish, but remain fundamentally limited in speed. Here we have developed SPED light sheet microscopy, which combines large volumetric field-of-view via an extended depth of field with the optical sectioning of light sheet microscopy, thereby eliminating the need to physically scan detection objectives for volumetric imaging. SPED enables scanning of thousands of volumes-per-second, limited only by camera acquisition rate, through the harnessing of optical mechanisms that normally result in unwanted spherical aberrations. We demonstrate capabilities of SPED microscopy by performing fast sub-cellular resolution imaging of CLARITY mouse brains and cellular-resolution volumetric Ca2+ imaging of entire zebrafish nervous systems. Together, SPED light sheet methods enable high-speed cellular-resolution volumetric mapping of biological system structure and function. PMID:26687363

Normal forms for Poisson maps and symplectic groupoids around Poisson transversals

NASA Astrophysics Data System (ADS)

Frejlich, Pedro; Mărcuț, Ioan

2018-03-01

Poisson transversals are submanifolds in a Poisson manifold which intersect all symplectic leaves transversally and symplectically. In this communication, we prove a normal form theorem for Poisson maps around Poisson transversals. A Poisson map pulls a Poisson transversal back to a Poisson transversal, and our first main result states that simultaneous normal forms exist around such transversals, for which the Poisson map becomes transversally linear, and intertwines the normal form data of the transversals. Our second result concerns symplectic integrations. We prove that a neighborhood of a Poisson transversal is integrable exactly when the Poisson transversal itself is integrable, and in that case we prove a normal form theorem for the symplectic groupoid around its restriction to the Poisson transversal, which puts all structure maps in normal form. We conclude by illustrating our results with examples arising from Lie algebras.

Normal forms for Poisson maps and symplectic groupoids around Poisson transversals.

PubMed

Frejlich, Pedro; Mărcuț, Ioan

2018-01-01

Poisson transversals are submanifolds in a Poisson manifold which intersect all symplectic leaves transversally and symplectically. In this communication, we prove a normal form theorem for Poisson maps around Poisson transversals. A Poisson map pulls a Poisson transversal back to a Poisson transversal, and our first main result states that simultaneous normal forms exist around such transversals, for which the Poisson map becomes transversally linear, and intertwines the normal form data of the transversals. Our second result concerns symplectic integrations. We prove that a neighborhood of a Poisson transversal is integrable exactly when the Poisson transversal itself is integrable, and in that case we prove a normal form theorem for the symplectic groupoid around its restriction to the Poisson transversal, which puts all structure maps in normal form. We conclude by illustrating our results with examples arising from Lie algebras.

Morphology of uranium electrodeposits on cathode in electrorefining process: A phase-field simulation

NASA Astrophysics Data System (ADS)

Shibuta, Yasushi; Sato, Takumi; Suzuki, Toshio; Ohta, Hirokazu; Kurata, Masaki

2013-05-01

Morphology of uranium electrodeposits on cathode with respect to applied voltage, zirconium concentration in the molten salt and the size of primary deposit during pyroprocessing is systematically investigated by the phase-field simulation. It is found that there is a threshold zirconium concentration in the molten salt demarcating planar and cellular/needle-like electrodeposits, which agrees with experimental results. In addition, the effect of size of primary deposits on the morphology of electrodeposits is examined. It is then confirmed that cellular/needle-like electrodeposits are formed from large primary deposits at all applied voltages considered, whereas both the planar and cellular/needle-like electrodeposits are formed from the primary deposits of 10 μm and less.

Defective granulocyte chemotaxis in the Chediak-Higashi syndrome

PubMed Central

Clark, Robert A.; Kimball, Harry R.

1971-01-01

In vivo and in vitro studies of granulocyte chemotaxis were performed in three patients with the Chediak-Higashi syndrome. Rebuck skin windows showed a decreased accumulation of leukocytes at an inflammatory site. Studies in Boyden chambers documented a cellular defect in granulocyte chemotaxis. The chemotactic response of Chediak-Higashi cells by this technique averaged approximately 40% of normal and was consistently reduced using several different chemotactic stimuli. This deficit was magnified by shortening the chamber incubation time or by decreasing the pore size of the micropore filter and was independent of granulocytopenia. No abnormalities of passive motility, adhesiveness, viability, or pH optimum for migration were found in these cells. Chediak-Higashi serum contained no inhibitors of chemotaxis and was capable of generating normal amounts of chemotactic factors with the exception of one patient with the accelerated phase of the disease. Heterozygotes for the Chediak-Higashi trait had normal chemotactic function. This cellular defect in chemotaxis may contribute to the marked susceptibility to pyogenic infections which is so characteristic of patients with the Chediak-Higashi syndrome. Images PMID:4942966

Functions of autophagy in normal and diseased liver

PubMed Central

Czaja, Mark J.; Ding, Wen-Xing; Donohue, Terrence M.; Friedman, Scott L.; Kim, Jae-Sung; Komatsu, Masaaki; Lemasters, John J.; Lemoine, Antoinette; Lin, Jiandie D.; Ou, Jing-hsiung James; Perlmutter, David H.; Randall, Glenn; Ray, Ratna B.; Tsung, Allan; Yin, Xiao-Ming

2013-01-01

Autophagy has emerged as a critical lysosomal pathway that maintains cell function and survival through the degradation of cellular components such as organelles and proteins. Investigations specifically employing the liver or hepatocytes as experimental models have contributed significantly to our current knowledge of autophagic regulation and function. The diverse cellular functions of autophagy, along with unique features of the liver and its principal cell type the hepatocyte, suggest that the liver is highly dependent on autophagy for both normal function and to prevent the development of disease states. However, instances have also been identified in which autophagy promotes pathological changes such as the development of hepatic fibrosis. Considerable evidence has accumulated that alterations in autophagy are an underlying mechanism of a number of common hepatic diseases including toxin-, drug- and ischemia/reperfusion-induced liver injury, fatty liver, viral hepatitis and hepatocellular carcinoma. This review summarizes recent advances in understanding the roles that autophagy plays in normal hepatic physiology and pathophysiology with the intent of furthering the development of autophagy-based therapies for human liver diseases. PMID:23774882

Research in Biological and Medical Sciences Including Biochemistry, Communicable Disease and Immunology, Internal Medicine, Nuclear Medicine, Physiology, Psychiatry, Surgery, and Veterinary Medicine. Volume 2

DTIC Science & Technology

1974-06-30

Sprinz and Formal 1968). Fat seen in colonic epithelial cells of monkeys infected by Shigella flexneri occurred before penetration of...cellular or non-cellular components of the peripheral blood such as fat , fibrin, denatured protein, red blood cells, intact neutrophils or other...in vitro, and imply their embolic character when infused into the recipient’s vasculature. Corclusion Storage of whole blood under normal blood bank

ALTERATIONS OF MACROPHAGE FUNCTIONS BY MEDIATORS FROM LYMPHOCYTES

PubMed Central

Nathan, Carl F.; Karnovsky, Manfred L.; David, John R.

1971-01-01

Sensitized lymphocytes were incubated in vitro with the specific antigen Supernatants from these cultures were chromatographed on Sephadex G-100 columns. Supernatant fractions containing MIF, chemotactic factor, and lymphotoxin, but free of antigen and antibody, were incubated with normal peritoneal exudate macrophages. Macrophage adherence, phagocytosis, spreading, motility, and direct hexose monophosphate oxidation were enhanced, while protein synthesis was unaffected. Thus, antigen-stimulated lymphocytes secrete a factor or factors which enhance certain macrophage functions. Implications for models of cellular immunity and cellular hypersensitivity are discussed. PMID:5576335

Kap121p-Mediated Nuclear Import Is Required for Mating and Cellular Differentiation in Yeast

PubMed Central

Leslie, Deena M.; Grill, Brock; Rout, Michael P.; Wozniak, Richard W.; Aitchison, John D.

2002-01-01

To further our understanding of how the nucleocytoplasmic transport machinery interfaces with its cargoes and how this affects cellular physiology, we investigated the molecular mechanisms of phenotypes associated with mutations in karyopherin Kap121p. Two previously unreported phenotypes of kap121 cells were observed: defects in mating and in the transition from the normal yeast form to the pseudohyphal, invasive form. In parallel, we searched for Kap121p cargoes by using Kap121p as a probe in overlay assays of yeast nuclear proteins. One of the major interacting proteins identified by this procedure was Ste12p, a transcription factor central to both the mating response and the pseudohyphal transition. We therefore investigated whether defects in these differentiation processes were due to an inability to import Ste12p. Both immunopurification and in vitro binding studies demonstrated that Ste12p interacted specifically with Kap121p in a Ran-GTP-sensitive manner and that Ste12p was mislocalized to the cytoplasm by inactivation of Kap121p in a temperature-sensitive mutant. The Kap121p-specific nuclear localization signal (NLS) of Ste12p was determined to reside within a C-terminal region of Ste12p. Furthermore, by overexpression of STE12 or expression of a STE12-cNLS fusion in kap121 cells, the invasive-growth defect and the mating defect were both suppressed. Together these data demonstrate that Ste12p is imported into nuclei by Kap121p and that mating and differentiation defects associated with kap121 mutants are primarily attributable to the mislocalization of Ste12p. PMID:11909949

Developing Inhibitors of Translesion DNA Synthesis as Therapeutic Agents against Lung Cancer

DTIC Science & Technology

2015-12-01

normal DNA synthesis. In contrast, pol eta shows a combination of high efficiency and low fidelity when replicating 8-oxo-G. These combined properties...are consistent with a pro- mutagenic role for pol eta when replicating this DNA lesion under cellular conditions. Studies with modified nucleotide...analogs indicate that pol eta relies heavily on hydrogen-bonding interactions during normal and translesion synthesis. However, some nucleobase

Deep sequencing of the small RNA transcriptome of normal and malignant human B cells identifies hundreds of novel microRNAs

PubMed Central

Jima, Dereje D.; Zhang, Jenny; Jacobs, Cassandra; Richards, Kristy L.; Dunphy, Cherie H.; Choi, William W. L.; Yan Au, Wing; Srivastava, Gopesh; Czader, Magdalena B.; Rizzieri, David A.; Lagoo, Anand S.; Lugar, Patricia L.; Mann, Karen P.; Flowers, Christopher R.; Bernal-Mizrachi, Leon; Naresh, Kikkeri N.; Evens, Andrew M.; Gordon, Leo I.; Luftig, Micah; Friedman, Daphne R.; Weinberg, J. Brice; Thompson, Michael A.; Gill, Javed I.; Liu, Qingquan; How, Tam; Grubor, Vladimir; Gao, Yuan; Patel, Amee; Wu, Han; Zhu, Jun; Blobe, Gerard C.; Lipsky, Peter E.; Chadburn, Amy

2010-01-01

A role for microRNA (miRNA) has been recognized in nearly every biologic system examined thus far. A complete delineation of their role must be preceded by the identification of all miRNAs present in any system. We elucidated the complete small RNA transcriptome of normal and malignant B cells through deep sequencing of 31 normal and malignant human B-cell samples that comprise the spectrum of B-cell differentiation and common malignant phenotypes. We identified the expression of 333 known miRNAs, which is more than twice the number previously recognized in any tissue type. We further identified the expression of 286 candidate novel miRNAs in normal and malignant B cells. These miRNAs were validated at a high rate (92%) using quantitative polymerase chain reaction, and we demonstrated their application in the distinction of clinically relevant subgroups of lymphoma. We further demonstrated that a novel miRNA cluster, previously annotated as a hypothetical gene LOC100130622, contains 6 novel miRNAs that regulate the transforming growth factor-β pathway. Thus, our work suggests that more than a third of the miRNAs present in most cellular types are currently unknown and that these miRNAs may regulate important cellular functions. PMID:20733160

Modulation of cytotoxic T lymphocyte, natural killer cell, antibody-dependent cellular cytotoxicity, and antibody-dependent complement-mediated cytotoxicity by Vernonia cinerea L. and vernolide-A in BALB/c mice via enhanced production of cytokines IL-2 and IFN-γ.

PubMed

Pratheeshkumar, Poyil; Kuttan, Girija

2012-02-01

Effect of Vernonia cinerea L. and vernolide-A on cell-mediated immune (CMI) response was studied in normal as well as tumor-bearing BALB/c mice. Administration of V. cinerea and vernolide-A significantly enhanced natural killer (NK) cell activity in both normal as well as tumor-bearing animals, and the activity was observed earlier than in tumor-bearing control animals. Antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent complement-mediated cytotoxicity (ACC) were also enhanced significantly in both normal as well as tumor-bearing animals after V. cinerea and vernolide-A administration compared with untreated control tumor-bearing animals. Extract and vernolide-A showed a significant increase in cytotoxic T lymphocyte (CTL) production in both the in vivo and in vitro models. The level of cytokines such as interleukin (IL)-2 and interferon (IFN)-γ were also enhanced by the treatment of V. cinerea and vernolide-A in both normal as well as tumor-bearing animals. This study demonstrated that V. cinerea extract and vernolide-A stimulate the CTL, NK cell, ADCC, and ADCC through enhanced secretion of IL-2 and IFN-γ.

Structural and functional consequences of antigenic modulation of red blood cells with methoxypoly(ethylene glycol).

PubMed

Murad, K L; Mahany, K L; Brugnara, C; Kuypers, F A; Eaton, J W; Scott, M D

1999-03-15

We previously showed that the covalent modification of the red blood cell (RBC) surface with methoxypoly(ethylene glycol) [mPEG; MW approximately 5 kD] could significantly attenuate the immunologic recognition of surface antigens. However, to make these antigenically silent RBC a clinically viable option, the mPEG-modified RBC must maintain normal cellular structure and functions. To this end, mPEG-derivatization was found to have no significant detrimental effects on RBC structure or function at concentrations that effectively blocked antigenic recognition of a variety of RBC antigens. Importantly, RBC lysis, morphology, and hemoglobin oxidation state were unaffected by mPEG-modification. Furthermore, as shown by functional studies of Band 3, a major site of modification, PEG-binding does not affect protein function, as evidenced by normal SO4- flux. Similarly, Na+ and K+ homeostasis were unaffected. The functional aspects of the mPEG-modified RBC were also maintained, as evidenced by normal oxygen binding and cellular deformability. Perhaps most importantly, mPEG-derivatized mouse RBC showed normal in vivo survival ( approximately 50 days) with no sensitization after repeated transfusions. These data further support the hypothesis that the covalent attachment of nonimmunogenic materials (eg, mPEG) to intact RBC may have significant application in transfusion medicine, especially for the chronically transfused and/or allosensitized patient.

Quantitative optical imaging of paracetamol-induced metabolism changes in the liver

NASA Astrophysics Data System (ADS)

Liang, Xiaowen; Wang, Haolu; Liu, Xin; Roberts, Michael

2016-12-01

Paracetamol is the most readily available and widely used painkiller. However, its toxicity remains the most common cause of liver injury. The toxicity of paracetamol has been attributing to its toxic metabolite, which depletes cellular glutathione (GSH) stores and reacts within cells to increase oxidative stress, leading to mitochondrial dysfunction and cell necrosis. Multiphoton microscopy (MPM) and fluorescence lifetime imaging (FLIM) can provide quantitative imaging of biological tissues and organs in vivo and allow direct visualization of cellular events, which were used to monitor cellular metabolism in paracetamol-induced toxicity in this study. To better understand mechanisms of paracetamol induced liver injury, the redox ratio of NADH/FAD in liver cells were detected and quantified by MPM imaging to represent the relative rates of glycolysis and oxidative phosphorylation within cells. Compared to normal liver, average fluorescence lifetime of NADH and redox ratio of NADH/FAD in hepatocytes was significantly decreased after paracetamol overdose for 12 and 24 hrs, reflecting impaired metabolic activity. GSH levels of treatment groups were significantly lower than those of normal livers, with gradually decreasing from periportal to centrilobular zonation. This imaging technique has significant implications for investigating metabolic mechanisms of paracetamol toxicity.

Assay to detect lipid peroxidation upon exposure to nanoparticles.

PubMed

Potter, Timothy M; Neun, Barry W; Stern, Stephan T

2011-01-01

This chapter describes a method for the analysis of human hepatocarcinoma cells (HEP G2) for lipid peroxidation products, such as malondialdehyde (MDA), following treatment with nanoparticle formulations. Oxidative stress has been identified as a likely mechanism of nanoparticle toxicity, and cell-based in vitro systems for evaluation of nanoparticle-induced oxidative stress are widely considered to be an important component of biocompatibility screens. The products of lipid peroxidation, lipid hydroperoxides, and aldehydes, such as MDA, can be measured via a thiobarbituric acid reactive substances (TBARS) assay. In this assay, which can be performed in cell culture or in cell lysate, MDA combines with thiobarbituric acid (TBA) to form a fluorescent adduct that can be detected at an excitation wavelength of 530 nm and an emission wavelength of 550 nm. The results are then expressed as MDA equivalents, normalized to total cellular protein (determined by Bradford assay).

The role of STATs in lung carcinogenesis: an emerging target for novel therapeutics.

PubMed

Karamouzis, Michalis V; Konstantinopoulos, Panagiotis A; Papavassiliou, Athanasios G

2007-05-01

The signal transducer and activator of transcription (STAT) proteins are a family of latent cytoplasmic transcription factors, which form dimers when activated by cytokine receptors, tyrosine kinase growth factor receptors as well as non-receptor tyrosine kinases. Dimeric STATs translocate to the nucleus, where they bind to specific DNA-response elements in the promoters of target genes, thereby inducing unique gene expression programs often in association with other transcription regulatory proteins. The functional consequence of different STAT proteins activation varies, as their target genes play diverse roles in normal cellular/tissue functions, including growth, apoptosis, differentiation and angiogenesis. Certain activated STATs have been implicated in human carcinogenesis, albeit only few studies have focused into their role in lung tumours. Converging evidence unravels their molecular interplays and complex multipartite regulation, rendering some of them appealing targets for lung cancer treatment with new developing strategies.

Effects of Hypogravity on Osteoblast Differentiation

NASA Technical Reports Server (NTRS)

Globus, Ruth; Doty, Steven

1997-01-01

Weightbearing is essential for normal skeletal function. Without weightbearing, the rate of bone formation by osteoblasts decreases in the growing rat. Defective formation may account for the decrease in the maturation, strength and mass of bone that is caused by spaceflight. These skeletal defects may be mediated by a combination of physiologic changes triggered by spaceflight, including skeletal unloading, fluid shifts, and stress-induced endocrine factors. The fundamental question of whether the defects in osteoblast function due to weightlessness are mediated by localized skeletal unloading or by systemic physiologic adaptations such as fluid shifts has not been answered. Furthermore, bone-forming activity of osteoblasts during unloading may be affected by paracrine signals from vascular, monocytic, and neural cells that also reside in skeletal tissue. Therefore we proposed to examine whether exposure of cultured rat osteoblasts to spaceflight inhibits cellular differentiation and impairs mineralization when isolated from the influence of both systemic factors and other skeletal cells.

[Structure and function of suburothelial myofibroblasts in the human urinary bladder under normal and pathological conditions].

PubMed

Neuhaus, J; Heinrich, M; Schlichting, N; Oberbach, A; Fitzl, G; Schwalenberg, T; Horn, L-C; Stolzenburg, J-U

2007-09-01

Myofibroblasts play a pivotal role in numerous pathological alterations. Clarification of the structure and function and of the cellular plasticity of this cell type in the bladder may lead to new insights into the pathogenesis of lower urinary tract disorders. Bladder biopsies from patients with bladder carcinoma and interstitial cystitis were used to analyse the morphology and receptor expression using confocal immunofluorescence and electron microscopy. Cytokine effects and coupling behavior were tested in cultured myofibroblasts and detrusor smooth muscle cells. Myofibroblasts are in close contact with the suburothelial capillary network. They express Cx43 and form functional syncytia. The expression of muscarinic and purinergic receptors is highly variable. Dye coupling experiments showed differences to detrusor myocytes. Upregulation of smooth muscle cell alpha-actin and/or transdifferentiation into smooth muscle cells may contribute to the etiology of urge incontinence. A multi-step model is presented as a working hypothesis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kasper, Jocelyn S.; Harvard Medical School, Boston, MA; Arai, Takehiro

CUL7 is a member of the cullin RING ligase family and forms an SCF-like complex with SKP1 and FBXW8. CUL7 is required for normal mouse embryonic development and cellular proliferation, and is highly homologous to PARC, a p53-associated, parkin-like cytoplasmic protein. We determined that CUL7, in a manner similar to PARC, can bind directly to p53 but does not affect p53 expression. We identified a discrete, co-linear domain in CUL7 that is conserved in PARC and HERC2, and is necessary and sufficient for p53-binding. The presence of p53 stabilized expression of this domain and we demonstrate that this p53-binding domainmore » of CUL7 contributes to the cytoplasmic localization of CUL7. The results support the model that p53 plays a role in regulation of CUL7 activity.« less

Rapid Engineering of Three-Dimensional, Multicellular Tissues With Polymeric Scaffolds

NASA Technical Reports Server (NTRS)

Gonda, Steve R.; Jordan, Jacqueline; Fraga, Denise N.

2007-01-01

A process has been developed for the rapid tissue engineering of multicellular-tissue-equivalent assemblies by the controlled enzymatic degradation of polymeric beads in a low-fluid-shear bioreactor. In this process, the porous polymeric beads serve as temporary scaffolds to support the assemblies of cells in a tissuelike 3D configuration during the critical initial growth phases of attachment of anchorage-dependent cells, aggregation of the cells, and formation of a 3D extracellular matrix. Once the cells are assembled into a 3D array and enmeshed in a structural supportive 3D extracellular matrix (ECM), the polymeric scaffolds can be degraded in the low-fluid-shear environment of the NASA-designed bioreactor. The natural 3D tissuelike assembly, devoid of any artificial support structure, is maintained in the low-shear bioreactor environment by the newly formed natural cellular/ECM. The elimination of the artificial scaffold allows normal tissue structure and function.

Chemotherapeutic agents for the treatment of metastatic breast cancer: An update.

PubMed

Abotaleb, Mariam; Kubatka, Peter; Caprnda, Martin; Varghese, Elizabeth; Zolakova, Barbora; Zubor, Pavol; Opatrilova, Radka; Kruzliak, Peter; Stefanicka, Patrik; Büsselberg, Dietrich

2018-05-01

Breast cancer is the second greatest cause of death among women worldwide; it comprises a group of heterogeneous diseases that evolves due to uncontrolled cellular growth and differentiation and the loss of normal programmed cell death. There are different molecular sub-types of breast cancer; therefore, various options are selected for treatment of different forms of metastatic breast cancer. However, the use of chemotherapeutic drugs is usually accompanied by deleterious side effects and the development of drug resistance when applied for a longer period. This review offers a classification of these chemotherapeutic agents according to their modes of action and therefore improves the understanding of molecular targets that are affected during treatment. Overall, it will allow the clinician to identify more specific targets to increase the effectiveness of a drug and to reduce general toxicity, resistance and other side effects. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Global functional analyses of cellular responses to pore-forming toxins.

PubMed

Kao, Cheng-Yuan; Los, Ferdinand C O; Huffman, Danielle L; Wachi, Shinichiro; Kloft, Nicole; Husmann, Matthias; Karabrahimi, Valbona; Schwartz, Jean-Louis; Bellier, Audrey; Ha, Christine; Sagong, Youn; Fan, Hui; Ghosh, Partho; Hsieh, Mindy; Hsu, Chih-Shen; Chen, Li; Aroian, Raffi V

2011-03-01

Here we present the first global functional analysis of cellular responses to pore-forming toxins (PFTs). PFTs are uniquely important bacterial virulence factors, comprising the single largest class of bacterial protein toxins and being important for the pathogenesis in humans of many Gram positive and Gram negative bacteria. Their mode of action is deceptively simple, poking holes in the plasma membrane of cells. The scattered studies to date of PFT-host cell interactions indicate a handful of genes are involved in cellular defenses to PFTs. How many genes are involved in cellular defenses against PFTs and how cellular defenses are coordinated are unknown. To address these questions, we performed the first genome-wide RNA interference (RNAi) screen for genes that, when knocked down, result in hypersensitivity to a PFT. This screen identifies 106 genes (∼0.5% of genome) in seven functional groups that protect Caenorhabditis elegans from PFT attack. Interactome analyses of these 106 genes suggest that two previously identified mitogen-activated protein kinase (MAPK) pathways, one (p38) studied in detail and the other (JNK) not, form a core PFT defense network. Additional microarray, real-time PCR, and functional studies reveal that the JNK MAPK pathway, but not the p38 MAPK pathway, is a key central regulator of PFT-induced transcriptional and functional responses. We find C. elegans activator protein 1 (AP-1; c-jun, c-fos) is a downstream target of the JNK-mediated PFT protection pathway, protects C. elegans against both small-pore and large-pore PFTs and protects human cells against a large-pore PFT. This in vivo RNAi genomic study of PFT responses proves that cellular commitment to PFT defenses is enormous, demonstrates the JNK MAPK pathway as a key regulator of transcriptionally-induced PFT defenses, and identifies AP-1 as the first cellular component broadly important for defense against large- and small-pore PFTs.

Local bifurcations in differential equations with state-dependent delay.

PubMed

Sieber, Jan

2017-11-01

A common task when analysing dynamical systems is the determination of normal forms near local bifurcations of equilibria. As most of these normal forms have been classified and analysed, finding which particular class of normal form one encounters in a numerical bifurcation study guides follow-up computations. This paper builds on normal form algorithms for equilibria of delay differential equations with constant delay that were developed and implemented in DDE-Biftool recently. We show how one can extend these methods to delay-differential equations with state-dependent delay (sd-DDEs). Since higher degrees of regularity of local center manifolds are still open for sd-DDEs, we give an independent (still only partial) argument which phenomena from the truncated normal must persist in the full sd-DDE. In particular, we show that all invariant manifolds with a sufficient degree of normal hyperbolicity predicted by the normal form exist also in the full sd-DDE.

Determination of cell cycle phases in live B16 melanoma cells using IRMS.

PubMed

Bedolla, Diana E; Kenig, Saša; Mitri, Elisa; Ferraris, Paolo; Marcello, Alessandro; Grenci, Gianluca; Vaccari, Lisa

2013-07-21

The knowledge of cell cycle phase distribution is of paramount importance for understanding cellular behaviour under normal and stressed growth conditions. This task is usually assessed using Flow Cytometry (FC) or immunohistochemistry. Here we report on the use of FTIR microspectroscopy in Microfluidic Devices (MD-IRMS) as an alternative technique for studying cell cycle distribution in live cells. Asynchronous, S- and G0-synchronized B16 mouse melanoma cells were studied by running parallel experiments based on MD-IRMS and FC using Propidium Iodide (PI) staining. MD-IRMS experiments have been done using silicon-modified BaF2 devices, where the thin silicon layer prevents BaF2 dissolution without affecting the transparency of the material and therefore enabling a better assessment of the Phosphate I (PhI) and II (PhII) bands. Hierarchical Cluster Analysis (HCA) of cellular microspectra in the 1300-1000 cm(-1) region pointed out a distribution of cells among clusters, which is in good agreement with FC results among G0/G1, S and G2/M phases. The differentiation is mostly driven by the intensity of PhI and PhII bands. In particular, PhI almost doubles from the G0/G1 to G2/M phase, in agreement with the trend followed by nucleic acids during cellular progression. MD-IRMS is then proposed as a powerful method for the in situ determination of the cell cycle stage of an individual cell, without any labelling or staining, which gives the advantage of possibly monitoring specific cellular responses to several types of stimuli by clearly separating the spectral signatures related to the cellular response from those of cells that are normally progressing.

a Recursive Approach to Compute Normal Forms

NASA Astrophysics Data System (ADS)

HSU, L.; MIN, L. J.; FAVRETTO, L.

2001-06-01

Normal forms are instrumental in the analysis of dynamical systems described by ordinary differential equations, particularly when singularities close to a bifurcation are to be characterized. However, the computation of a normal form up to an arbitrary order is numerically hard. This paper focuses on the computer programming of some recursive formulas developed earlier to compute higher order normal forms. A computer program to reduce the system to its normal form on a center manifold is developed using the Maple symbolic language. However, it should be stressed that the program relies essentially on recursive numerical computations, while symbolic calculations are used only for minor tasks. Some strategies are proposed to save computation time. Examples are presented to illustrate the application of the program to obtain high order normalization or to handle systems with large dimension.

Evidence for Functional Differentiation among Drosophila Septins in Cytokinesis and Cellularization

PubMed Central

Adam, Jennifer C.; Pringle, John R.; Peifer, Mark

2000-01-01

The septins are a conserved family of proteins that are involved in cytokinesis and other aspects of cell-surface organization. In Drosophila melanogaster, null mutations in the pnut septin gene are recessive lethal, but homozygous pnut mutants complete embryogenesis and survive until the pupal stage. Because the completion of cellularization and other aspects of early development seemed likely to be due to maternally contributed Pnut product, we attempted to generate embryos lacking the maternal contribution in order to explore the roles of Pnut in these processes. We used two methods, the production of germline clones homozygous for a pnut mutation and the rescue of pnut homozygous mutant flies by a pnut+ transgene under control of the hsp70 promoter. Remarkably, the pnut germline-clone females produced eggs, indicating that stem-cell and cystoblast divisions in the female germline do not require Pnut. Moreover, the Pnut-deficient embryos obtained by either method completed early syncytial development and began cellularization of the embryo normally. However, during the later stages of cellularization, the organization of the actin cytoskeleton at the leading edge of the invaginating furrows became progressively more abnormal, and the embryos displayed widespread defects in cell and embryo morphology beginning at gastrulation. Examination of two other septins showed that Sep1 was not detectable at the cellularization front in the Pnut-deficient embryos, whereas Sep2 was still present in normal levels. Thus, it is possible that Sep2 (perhaps in conjunction with other septins such as Sep4 and Sep5) fulfills an essential septin role during the organization and initial ingression of the cellularization furrow even in the absence of Pnut and Sep1. Together, the results suggest that some cell-division events in Drosophila do not require septin function, that there is functional differentiation among the Drosophila septins, or both. PMID:10982405

High-Fidelity Tissue Engineering of Patient-Specific Auricles for Reconstruction of Pediatric Microtia and Other Auricular Deformities

PubMed Central

Reiffel, Alyssa J.; Kafka, Concepcion; Hernandez, Karina A.; Popa, Samantha; Perez, Justin L.; Zhou, Sherry; Pramanik, Satadru; Brown, Bryan N.; Ryu, Won Seuk; Bonassar, Lawrence J.; Spector, Jason A.

2013-01-01

Introduction Autologous techniques for the reconstruction of pediatric microtia often result in suboptimal aesthetic outcomes and morbidity at the costal cartilage donor site. We therefore sought to combine digital photogrammetry with CAD/CAM techniques to develop collagen type I hydrogel scaffolds and their respective molds that would precisely mimic the normal anatomy of the patient-specific external ear as well as recapitulate the complex biomechanical properties of native auricular elastic cartilage while avoiding the morbidity of traditional autologous reconstructions. Methods Three-dimensional structures of normal pediatric ears were digitized and converted to virtual solids for mold design. Image-based synthetic reconstructions of these ears were fabricated from collagen type I hydrogels. Half were seeded with bovine auricular chondrocytes. Cellular and acellular constructs were implanted subcutaneously in the dorsa of nude rats and harvested after 1 and 3 months. Results Gross inspection revealed that acellular implants had significantly decreased in size by 1 month. Cellular constructs retained their contour/projection from the animals' dorsa, even after 3 months. Post-harvest weight of cellular constructs was significantly greater than that of acellular constructs after 1 and 3 months. Safranin O-staining revealed that cellular constructs demonstrated evidence of a self-assembled perichondrial layer and copious neocartilage deposition. Verhoeff staining of 1 month cellular constructs revealed de novo elastic cartilage deposition, which was even more extensive and robust after 3 months. The equilibrium modulus and hydraulic permeability of cellular constructs were not significantly different from native bovine auricular cartilage after 3 months. Conclusions We have developed high-fidelity, biocompatible, patient-specific tissue-engineered constructs for auricular reconstruction which largely mimic the native auricle both biomechanically and histologically, even after an extended period of implantation. This strategy holds immense potential for durable patient-specific tissue-engineered anatomically proper auricular reconstructions in the future. PMID:23437148

Untangling the origin of viruses and their impact on cellular evolution.

PubMed

Nasir, Arshan; Sun, Feng-Jie; Kim, Kyung Mo; Caetano-Anollés, Gustavo

2015-04-01

The origin and evolution of viruses remain mysterious. Here, we focus on the distribution of viral replicons in host organisms, their morphological features, and the evolution of highly conserved protein and nucleic acid structures. The apparent inability of RNA viral replicons to infect contemporary akaryotic species suggests an early origin of RNA viruses and their subsequent loss in akaryotes. A census of virion morphotypes reveals that advanced forms were unique to viruses infecting a specific supergroup, while simpler forms were observed in viruses infecting organisms in all forms of cellular life. Results hint toward an ancient origin of viruses from an ancestral virus harboring either filamentous or spherical virions. Finally, phylogenetic trees built from protein domain and tRNA structures in thousands of genomes suggest that viruses evolved via reductive evolution from ancient cells. The analysis presents a complete account of the evolutionary history of cells and viruses and identifies viruses as crucial agents influencing cellular evolution. © 2015 New York Academy of Sciences.

Method of forming a continuous polymeric skin on a cellular foam material

DOEpatents

Duchane, David V.; Barthell, Barry L.

1985-01-01

Hydrophobic cellular material is coated with a thin hydrophilic polymer skin which stretches tightly over the outer surface of the foam but which does not fill the cells of the foam, thus resulting in a polymer-coated foam structure having a smoothness which was not possible in the prior art. In particular, when the hydrophobic cellular material is a specially chosen hydrophobic polymer foam and is formed into arbitrarily chosen shapes prior to the coating with hydrophilic polymer, inertial confinement fusion (ICF) targets of arbitrary shapes can be produced by subsequently coating the shapes with metal or with any other suitable material. New articles of manufacture are produced, including improved ICF targets, improved integrated circuits, and improved solar reflectors and solar collectors. In the coating method, the cell size of the hydrophobic cellular material, the viscosity of the polymer solution used to coat, and the surface tensin of the polymer solution used to coat are all very important to the coating.

Designer amphiphilic proteins as building blocks for the intracellular formation of organelle-like compartments

NASA Astrophysics Data System (ADS)

Huber, Matthias C.; Schreiber, Andreas; von Olshausen, Philipp; Varga, Balázs R.; Kretz, Oliver; Joch, Barbara; Barnert, Sabine; Schubert, Rolf; Eimer, Stefan; Kele, Péter; Schiller, Stefan M.

2015-01-01

Nanoscale biological materials formed by the assembly of defined block-domain proteins control the formation of cellular compartments such as organelles. Here, we introduce an approach to intentionally ‘program’ the de novo synthesis and self-assembly of genetically encoded amphiphilic proteins to form cellular compartments, or organelles, in Escherichia coli. These proteins serve as building blocks for the formation of artificial compartments in vivo in a similar way to lipid-based organelles. We investigated the formation of these organelles using epifluorescence microscopy, total internal reflection fluorescence microscopy and transmission electron microscopy. The in vivo modification of these protein-based de novo organelles, by means of site-specific incorporation of unnatural amino acids, allows the introduction of artificial chemical functionalities. Co-localization of membrane proteins results in the formation of functionalized artificial organelles combining artificial and natural cellular function. Adding these protein structures to the cellular machinery may have consequences in nanobiotechnology, synthetic biology and materials science, including the constitution of artificial cells and bio-based metamaterials.

Inhibition of human copper trafficking by a small molecule significantly attenuates cancer cell proliferation.

PubMed

Wang, Jing; Luo, Cheng; Shan, Changliang; You, Qiancheng; Lu, Junyan; Elf, Shannon; Zhou, Yu; Wen, Yi; Vinkenborg, Jan L; Fan, Jun; Kang, Heebum; Lin, Ruiting; Han, Dali; Xie, Yuxin; Karpus, Jason; Chen, Shijie; Ouyang, Shisheng; Luan, Chihao; Zhang, Naixia; Ding, Hong; Merkx, Maarten; Liu, Hong; Chen, Jing; Jiang, Hualiang; He, Chuan

2015-12-01

Copper is a transition metal that plays critical roles in many life processes. Controlling the cellular concentration and trafficking of copper offers a route to disrupt these processes. Here we report small molecules that inhibit the human copper-trafficking proteins Atox1 and CCS, and so provide a selective approach to disrupt cellular copper transport. The knockdown of Atox1 and CCS or their inhibition leads to a significantly reduced proliferation of cancer cells, but not of normal cells, as well as to attenuated tumour growth in mouse models. We show that blocking copper trafficking induces cellular oxidative stress and reduces levels of cellular ATP. The reduced level of ATP results in activation of the AMP-activated protein kinase that leads to reduced lipogenesis. Both effects contribute to the inhibition of cancer cell proliferation. Our results establish copper chaperones as new targets for future developments in anticancer therapies.

Inhibition of human copper trafficking by a small molecule significantly attenuates cancer cell proliferation

PubMed Central

Wang, Jing; Luo, Cheng; Shan, Changliang; You, Qiancheng; Lu, Junyan; Elf, Shannon; Zhou, Yu; Wen, Yi; Vinkenborg, Jan L.; Fan, Jun; Kang, Heebum; Lin, Ruiting; Han, Dali; Xie, Yuxin; Karpus, Jason; Chen, Shijie; Ouyang, Shisheng; Luan, Chihao; Zhang, Naixia; Ding, Hong; Merkx, Maarten; Liu, Hong; Chen, Jing; Jiang, Hualiang; He, Chuan

2016-01-01

Copper is a transition metal that plays critical roles in many life processes. Controlling the cellular concentration and trafficking of copper offers a route to disrupt these processes. Here we report small molecules that inhibit the human copper-trafficking proteins Atox1 and CCS, and so provide a selective approach to disrupt cellular copper transport. The knockdown of Atox1 and CCS or their inhibition leads to a significantly reduced proliferation of cancer cells, but not of normal cells, as well as to attenuated tumour growth in mouse models. We show that blocking copper trafficking induces cellular oxidative stress and reduces levels of cellular ATP. The reduced level of ATP results in activation of the AMP-activated protein kinase that leads to reduced lipogenesis. Both effects contribute to the inhibition of cancer cell proliferation. Our results establish copper chaperones as new targets for future developments in anticancer therapies. PMID:26587712

The cellular immunity and oxidative stress markers in early pregnancy loss.

PubMed

Daglar, Korkut; Biberoglu, Ebru; Kirbas, Ayse; Dirican, Aylin Onder; Genc, Metin; Avci, Aslihan; Biberoglu, Kutay

2016-01-01

We investigated whether changes in cellular immunity and oxidative stress in pregnancy have any association with spontaneous miscarriage. Circulating adenosine deaminase (ADA) activity as a marker of cellular immunity and malondialdehyde (MDA) and catalase (CAT), glutathione peroxidase (GPx) as markers of T lymphocyte activation and parameters of oxidative stress and antioxidant defense were compared between 40 women with early pregnancy loss and another 40 women with ungoing healthy pregnancy. Women with miscarriage had higher serum ADA and GPx levels when compared with women with normal pregnancy (p = 0.034 and p < 0.001, respectively). Although serum MDA level was slightly higher in women with miscarriage, the difference was not significant (p = 0.083). CAT levels were alike in both groups. We have demonstrated an increased cellular immunity and perhaps a compensated oxidative stress related to increased antioxidant activation in women with early spontaneous pregnancy loss.

Microfluidic strategies for understanding the mechanics of cells and cell-mimetic systems

PubMed Central

Dahl, Joanna B.; Lin, Jung-Ming G.; Muller, Susan J.; Kumar, Sanjay

2016-01-01

Microfluidic systems are attracting increasing interest for the high-throughput measurement of cellular biophysical properties and for the creation of engineered cellular microenvironments. Here we review recent applications of microfluidic technologies to the mechanics of living cells and synthetic cell-mimetic systems. We begin by discussing the use of microfluidic devices to dissect the mechanics of cellular mimics such as capsules and vesicles. We then explore applications to circulating cells, including erythrocytes and other normal blood cells, and rare populations with potential disease diagnostic value, such as circulating tumor cells. We conclude by discussing how microfluidic devices have been used to investigate the mechanics, chemotaxis, and invasive migration of adherent cells. In these ways, microfluidic technologies represent an increasingly important toolbox for investigating cellular mechanics and motility at high throughput and in a format that lends itself to clinical translation. PMID:26134738

Inhibition of human copper trafficking by a small molecule significantly attenuates cancer cell proliferation

NASA Astrophysics Data System (ADS)

Wang, Jing; Luo, Cheng; Shan, Changliang; You, Qiancheng; Lu, Junyan; Elf, Shannon; Zhou, Yu; Wen, Yi; Vinkenborg, Jan L.; Fan, Jun; Kang, Heebum; Lin, Ruiting; Han, Dali; Xie, Yuxin; Karpus, Jason; Chen, Shijie; Ouyang, Shisheng; Luan, Chihao; Zhang, Naixia; Ding, Hong; Merkx, Maarten; Liu, Hong; Chen, Jing; Jiang, Hualiang; He, Chuan

2015-12-01

Copper is a transition metal that plays critical roles in many life processes. Controlling the cellular concentration and trafficking of copper offers a route to disrupt these processes. Here we report small molecules that inhibit the human copper-trafficking proteins Atox1 and CCS, and so provide a selective approach to disrupt cellular copper transport. The knockdown of Atox1 and CCS or their inhibition leads to a significantly reduced proliferation of cancer cells, but not of normal cells, as well as to attenuated tumour growth in mouse models. We show that blocking copper trafficking induces cellular oxidative stress and reduces levels of cellular ATP. The reduced level of ATP results in activation of the AMP-activated protein kinase that leads to reduced lipogenesis. Both effects contribute to the inhibition of cancer cell proliferation. Our results establish copper chaperones as new targets for future developments in anticancer therapies.

Methylene Blue Protects Astrocytes against Glucose Oxygen Deprivation by Improving Cellular Respiration

PubMed Central

Roy Choudhury, Gourav; Winters, Ali; Rich, Ryan M.; Ryou, Myoung-Gwi; Gryczynski, Zygmunt; Yuan, Fang; Yang, Shao-Hua; Liu, Ran

2015-01-01

Astrocytes outnumber neurons and serve many metabolic and trophic functions in the mammalian brain. Preserving astrocytes is critical for normal brain function as well as for protecting the brain against various insults. Our previous studies have indicated that methylene blue (MB) functions as an alternative electron carrier and enhances brain metabolism. In addition, MB has been shown to be protective against neurodegeneration and brain injury. In the current study, we investigated the protective role of MB in astrocytes. Cell viability assays showed that MB treatment significantly protected primary astrocytes from oxygen-glucose deprivation (OGD) & reoxygenation induced cell death. We also studied the effect of MB on cellular oxygen and glucose metabolism in primary astrocytes following OGD-reoxygenation injury. MB treatment significantly increased cellular oxygen consumption, glucose uptake and ATP production in primary astrocytes. In conclusion our study demonstrated that MB protects astrocytes against OGD-reoxygenation injury by improving astrocyte cellular respiration. PMID:25848957

Multi-scale Imaging of Cellular and Sub-cellular Structures using Scanning Probe Recognition Microscopy.

NASA Astrophysics Data System (ADS)

Chen, Q.; Rice, A. F.

2005-03-01

Scanning Probe Recognition Microscopy is a new scanning probe capability under development within our group to reliably return to and directly interact with a specific nanobiological feature of interest. In previous work, we have successfully recognized and classified tubular versus globular biological objects from experimental atomic force microscope images using a method based on normalized central moments [ref. 1]. In this paper we extend this work to include recognition schemes appropriate for cellular and sub-cellular structures. Globular cells containing tubular actin filaments are under investigation. Thus there are differences in external/internal shapes and scales. Continuous Wavelet Transform with a differential Gaussian mother wavelet is employed for multi- scale analysis. [ref. 1] Q. Chen, V. Ayres and L. Udpa, ``Biological Investigation Using Scanning Probe Recognition Microscopy,'' Proceedings 3rd IEEE Conference on Nanotechnology, vol. 2, p 863-865 (2003).

Cellular therapy in bone-tendon interface regeneration

PubMed Central

Rothrauff, Benjamin B; Tuan, Rocky S

2014-01-01

The intrasynovial bone-tendon interface is a gradual transition from soft tissue to bone, with two intervening zones of uncalcified and calcified fibrocartilage. Following injury, the native anatomy is not restored, resulting in inferior mechanical properties and an increased risk of re-injury. Recent in vivo studies provide evidence of improved healing when surgical repair of the bone-tendon interface is augmented with cells capable of undergoing chondrogenesis. In particular, cellular therapy in bone-tendon healing can promote fibrocartilage formation and associated improvements in mechanical properties. Despite these promising results in animal models, cellular therapy in human patients remains largely unexplored. This review highlights the development and structure-function relationship of normal bone-tendon insertions. The natural healing response to injury is discussed, with subsequent review of recent research on cellular approaches for improved healing. Finally, opportunities for translating in vivo findings into clinical practice are identified. PMID:24326955

Repression of anti-proliferative factor Tob1 in osteoarthritic cartilage

PubMed Central

Gebauer, Mathias; Saas, Joachim; Haag, Jochen; Dietz, Uwe; Takigawa, Masaharu; Bartnik, Eckart; Aigner, Thomas

2005-01-01

Osteoarthritis is the most common degenerative disorder of the modern world. However, many basic cellular features and molecular processes of the disease are poorly understood. In the present study we used oligonucleotide-based microarray analysis of genes of known or assumed relevance to the cellular phenotype to screen for relevant differences in gene expression between normal and osteoarthritic chondrocytes. Custom made oligonucleotide DNA arrays were used to screen for differentially expressed genes in normal (n = 9) and osteoarthritic (n = 10) cartilage samples. Real-time polymerase chain reaction (PCR) with gene-specific primers was used for quantification. Primary human adult articular chondrocytes and chondrosarcoma cell line HCS-2/8 were used to study changes in gene expression levels after stimulation with interleukin-1β and bone morphogenetic protein, as well as the dependence on cell differentiation. In situ hybridization with a gene-specific probe was applied to detect mRNA expression levels in fetal growth plate cartilage. Overall, more than 200 significantly regulated genes were detected between normal and osteoarthritic cartilage (P < 0.01). One of the significantly repressed genes, Tob1, encodes a protein belonging to a family involved in silencing cells in terms of proliferation and functional activity. The repression of Tob1 was confirmed by quantitative PCR and correlated to markers of chondrocyte activity and proliferation in vivo. Tob1 expression was also detected at a decreased level in isolated chondrocytes and in the chondrosarcoma cell line HCS-2/8. Again, in these cells it was negatively correlated with proliferative activity and positively with cellular differentiation. Altogether, the downregulation of the expression of Tob1 in osteoarthritic chondrocytes might be an important aspect of the cellular processes taking place during osteoarthritic cartilage degeneration. Activation, the reinitiation of proliferative activity and the loss of a stable phenotype are three major changes in osteoarthritic chondrocytes that are highly significantly correlated with the repression of Tob1 expression. PMID:15743474

Cytologic features of the normal pineal gland on squash preparations.

PubMed

Murro, Diana; Alsadi, Alaa; Nag, Sukriti; Arvanitis, Leonidas; Gattuso, Paolo

2014-11-01

As primary pineal lesions are extremely rare, many surgical pathologists are unfamiliar with normal pineal cytologic features. We describe cytologic features of the normal pineal gland in patients of varying ages and identify common diagnostic pitfalls. We performed a retrospective review of pineal gland biopsies performed at our institution, where approximately 30,000 surgical specimens are accessioned yearly, for the last 23 years. Only two pineal gland biopsies were found. Although both cases were initially diagnosed as low-grade gliomas on frozen section, the final diagnosis was benign pineal tissue based on light microscopy and immunohistochemistry results. Additionally, we performed squash preparations of five normal pineal gland autopsy specimens with Papanicolaou and Diff-Quik® (Dade Behring, Newark, DE) stains. Infant preparations were highly cellular smears composed of numerous, uniform, single cells with indistinct cytoplasm, small round-to-oval nuclei, fine chromatin, and absent nucleoli and calcifications. The vague microfollicular pattern mimicked a pineocytoma and the fine fibrillary background mimicked a glial neoplasm. Young adult smears were similar; however, microcalcifications were present with fewer background single cells. Older patients had much less cellular smears composed of small clusters of cells with fusiform-to-spindle nuclei, a fine chromatin pattern, and indistinct cytoplasmic borders. There were fewer background single cells and more microcalcifications. The cytologic features of the native pineal gland vary with age. Normal pineal tissue can be confused with a pineocytoma or low-grade glioma. Familiarity with normal pineal gland cytological features will help to avoid a potential misdiagnosis. © 2014 Wiley Periodicals, Inc.

Pyridostigmine bromide (PYR) alters immune function in B6C3F1 mice.

PubMed

Peden-Adams, M M; Dudley, A C; EuDaly, J G; Allen, C T; Gilkeson, G S; Keil, D E

2004-02-01

Pyridostigmine bromide (PYR) is an anticholinesterase drug indicated for the treatment of myasthenia gravis and neuromuscular blockade reversal. It acts as a reversible cholinesterase inhibitor and was used as a pretreatment for soldiers during Operation Desert Storm to protect against possible nerve gas attacks. Since that time, PYR has been implicated as a possible causative agent contributing to Gulf War Illness. PYR's mechanism of action has been well-delineated with regards to its effects on the nervous system, yet little is known regarding potential effects on immunological function. To evaluate the effects of PYR on immunological function, adult female B6C3F1 mice were gavaged daily for 14 days with PYR (0, 1, 5, 10, or 20 mg/kg/day). Immune parameters assessed were lymphoproliferation, natural killer cell activity, the SRBC-specific antibody plaque-forming cell (PFC) response, thymus and spleen weight and cellularity, and thymic and splenic CD4/CD8 lymphocyte subpopulations. Exposure to PYR did not alter splenic and thymus weight or splenic cellularity. However, 20 mg PYR/kg/day decreased thymic cellularity with decreases in both CD4+/CD8+ (20 mg/kg/day) and CD4-/CD8- (10 and 20 mg/kg/day) cell types. Functional immune assays indicated that lymphocyte proliferative responses and natural killer cell activity were normal; whereas exposure to PYR significantly decreased primary IgM antibody responses to a T-cell dependent antigen at the 1, 5, 10 and 20 mg/kg treatment levels for 14 days. This is the first study to examine the immunotoxicological effects of PYR and demonstrate that this compound selectively suppresses humoral antibody responses.

A practical and efficient cellular substrate for the generation of induced pluripotent stem cells from adults: blood-derived endothelial progenitor cells.

PubMed

Geti, Imbisaat; Ormiston, Mark L; Rouhani, Foad; Toshner, Mark; Movassagh, Mehregan; Nichols, Jennifer; Mansfield, William; Southwood, Mark; Bradley, Allan; Rana, Amer Ahmed; Vallier, Ludovic; Morrell, Nicholas W

2012-12-01

Induced pluripotent stem cells (iPSCs) have the potential to generate patient-specific tissues for disease modeling and regenerative medicine applications. However, before iPSC technology can progress to the translational phase, several obstacles must be overcome. These include uncertainty regarding the ideal somatic cell type for reprogramming, the low kinetics and efficiency of reprogramming, and karyotype discrepancies between iPSCs and their somatic precursors. Here we describe the use of late-outgrowth endothelial progenitor cells (L-EPCs), which possess several favorable characteristics, as a cellular substrate for the generation of iPSCs. We have developed a protocol that allows the reliable isolation of L-EPCs from peripheral blood mononuclear cell preparations, including frozen samples. As a proof-of-principle for clinical applications we generated EPC-iPSCs from both healthy individuals and patients with heritable and idiopathic forms of pulmonary arterial hypertension. L-EPCs grew clonally; were highly proliferative, passageable, and bankable; and displayed higher reprogramming kinetics and efficiencies compared with dermal fibroblasts. Unlike fibroblasts, the high efficiency of L-EPC reprogramming allowed for the reliable generation of iPSCs in a 96-well format, which is compatible with high-throughput platforms. Array comparative genome hybridization analysis of L-EPCs versus donor-matched circulating monocytes demonstrated that L-EPCs have normal karyotypes compared with their subject's reference genome. In addition, >80% of EPC-iPSC lines tested did not acquire any copy number variations during reprogramming compared with their parent L-EPC line. This work identifies L-EPCs as a practical and efficient cellular substrate for iPSC generation, with the potential to address many of the factors currently limiting the translation of this technology.

Simulating large-scale pedestrian movement using CA and event driven model: Methodology and case study

NASA Astrophysics Data System (ADS)

Li, Jun; Fu, Siyao; He, Haibo; Jia, Hongfei; Li, Yanzhong; Guo, Yi

2015-11-01

Large-scale regional evacuation is an important part of national security emergency response plan. Large commercial shopping area, as the typical service system, its emergency evacuation is one of the hot research topics. A systematic methodology based on Cellular Automata with the Dynamic Floor Field and event driven model has been proposed, and the methodology has been examined within context of a case study involving the evacuation within a commercial shopping mall. Pedestrians walking is based on Cellular Automata and event driven model. In this paper, the event driven model is adopted to simulate the pedestrian movement patterns, the simulation process is divided into normal situation and emergency evacuation. The model is composed of four layers: environment layer, customer layer, clerk layer and trajectory layer. For the simulation of movement route of pedestrians, the model takes into account purchase intention of customers and density of pedestrians. Based on evacuation model of Cellular Automata with Dynamic Floor Field and event driven model, we can reflect behavior characteristics of customers and clerks at the situations of normal and emergency evacuation. The distribution of individual evacuation time as a function of initial positions and the dynamics of the evacuation process is studied. Our results indicate that the evacuation model using the combination of Cellular Automata with Dynamic Floor Field and event driven scheduling can be used to simulate the evacuation of pedestrian flows in indoor areas with complicated surroundings and to investigate the layout of shopping mall.

Endogenous Voltage Potentials and the Microenvironment: Bioelectric Signals that Reveal, Induce and Normalize Cancer

PubMed Central

Chernet, Brook; Levin, Michael

2014-01-01

Cancer may be a disease of geometry: a misregulation of the field of information that orchestrates individual cells’ activities towards normal anatomy. Recent work identified molecular mechanisms underlying a novel system of developmental control: bioelectric gradients. Endogenous spatio-temporal differences in resting potential of non-neural cells provide instructive cues for cell regulation and complex patterning during embryogenesis and regeneration. It is now appreciated that these cues are an important layer of the dysregulation of cell: cell interactions that leads to cancer. Abnormal depolarization of resting potential (Vmem) is a convenient marker for neoplasia and activates a metastatic phenotype in genetically-normal cells in vivo. Moreover, oncogene expression depolarizes cells that form tumor-like structures, but is unable to form tumors if this depolarization is artificially prevented by misexpression of hyperpolarizing ion channels. Vmem triggers metastatic behaviors at considerable distance, mediated by transcriptional and epigenetic effects of electrically-modulated flows of serotonin and butyrate. While in vivo data on voltages in carcinogenesis comes mainly from the amphibian model, unbiased genetic screens and network profiling in rodents and human tissues reveal several ion channel proteins as bona fide oncogene and promising targets for cancer drug development. However, we propose that a focus on specific channel genes is just the tip of the iceberg. Bioelectric state is determined by post-translational gating of ion channels, not only from genetically-specified complements of ion translocators. A better model is a statistical dynamics view of spatial Vmem gradients. Cancer may not originate at the single cell level, since gap junctional coupling results in multi-cellular physiological networks with multiple stable attractors in bioelectrical state space. New medical applications await a detailed understanding of the mechanisms by which organ target morphology stored in real-time patterns of ion flows is perceived or mis-perceived by cells. Mastery of somatic voltage gradients will lead to cancer normalization or rebooting strategies, such as those that occur in regenerating and embryonic organs, resulting in transformative advances in basic biology and oncology. PMID:25525610

Hydrodynamic Instability and Thermal Coupling in a Dynamic Model of Liquid-Propellant Combustion

NASA Technical Reports Server (NTRS)

Margolis, S. B.

1999-01-01

For liquid-propellant combustion, the Landau/Levich hydrodynamic models have been combined and extended to account for a dynamic dependence of the burning rate on the local pressure and temperature fields. Analysis of these extended models is greatly facilitated by exploiting the realistic smallness of the gas-to-liquid density ratio rho. Neglecting thermal coupling effects, an asymptotic expression was then derived for the cellular stability boundary A(sub p)(k) where A(sub p) is the pressure sensitivity of the burning rate and k is the disturbance wavenumber. The results explicitly indicate the stabilizing effects of gravity on long-wave disturbances, and those of viscosity and surface tension on short-wave perturbations, and the instability associated with intermediate wavenumbers for critical negative values of A(sub p). In the limit of weak gravity, hydrodynamic instability in liquid-propellant combustion becomes a long-wave, instability phenomenon, whereas at normal gravity, this instability is first manifested through O(1) wavenumbers. In addition, surface tension and viscosity (both liquid and gas) each produce comparable effects in the large-wavenumber regime, thereby providing important modifications to the previous analyses in which one or more of these effects was neglected. For A(sub p)= O, the Landau/Levich results are recovered in appropriate limiting cases, although this typically corresponds to a hydrodynamically unstable parameter regime for p << 1. In addition to the classical cellular form of hydrodynamic stability, there exists a pulsating form corresponding to the loss of stability of steady, planar burning to time-dependent perturbations. This occurs for negative values of the parameter A(sub p), and is thus absent from the original Landau/Levich models. In the extended model, however, there exists a stable band of negative pressure sensitivities bounded above by the Landau type of instability, and below by this pulsating form of hydrodynamic instability. Indeed, nonsteady modes of combustion have been observed at low pressures in hydroxylammonium nitrate (HAN)-based liquid propellants, which often exhibit negative pressure sensitivities. While nonsteady combustion may correspond to secondary and higher-order bifurcations above the cellular boundary, it may also be a manifestation of this pulsating type of hydrodynamic instability. In the present work, a nonzero temperature sensitivity is incorporated into our previous asymptotic analyses. This entails a coupling of the energy equation to the previous purely hydrodynamic problem, and leads to a significant modification of the pulsating boundary such that, for sufficiently large values of the temperature-sensitivity parameter, liquid-propellant combustion can become intrinsically unstable to this alternative form of hydrodynamic instability. For simplicity, further attention is confined here to the inviscid version of the problem since, despite the fact that viscous and surface-tension effects are comparable, the qualitative nature of the cellular boundary remains preserved in the zero-viscosity limit, as does the existence of the pulsating boundary. The mathematical model adopts the classical assumption that there is no distributed reaction in either the liquid or gas phases, but now the reaction sheet, representing either a pyrolysis reaction or an exothermic decomposition at the liquid/gas interface, is assumed to depend on local conditions there.

Normal and leukaemic human haemopoietic cells in diffusion chamber. A morphological and functional CFU-C study.

PubMed

Laurent, M; Clémancey-Marcille, G; Hollard, D

1980-03-01

Leukaemic human bone marrow and peripheral blood cells were cultured for 25 d in diffusion chambers implanted into cyclophosphamide treated mice. Normal bone marrow cells were cultured simultaneously. These cells were studied both morphologically and functionally (CFU-C). The leukaemic cells behaved heterogeneously, 2 groups being distinguishable in accordance with their initial in vitro growth pattern (1: no growth or microcluster growth. 2: macrocluster growth). Group I showed progressive cellular death with a diminution of granulocytic progenitors and the appearance of a predominantly macrophagic population. This behaviour resembled that of the control group. The initial microcluster growth pattern remained identical throughout the entire culture period. Group 2, after considerable cellular death up to d 5, showed an explosive proliferation of the granulocytic progenitors and incomplete differentiation (up to myelocyte). The initial macrocluster growth pattern remained identical.

A cellular glass substrate solar concentrator

NASA Technical Reports Server (NTRS)

Bedard, R.; Bell, D.

1980-01-01

The design of a second generation point focusing solar concentration is discussed. The design is based on reflective gores fabricated of thin glass mirror bonded continuously to a contoured substrate of cellular glass. The concentrator aperture and structural stiffness was optimized for minimum concentrator cost given the performance requirement of delivering 56 kWth to a 22 cm diameter receiver aperture with a direct normal insolation of 845 watts sq m and an operating wind of 50 kmph. The reflective panel, support structure, drives, foundation and instrumentation and control subsystem designs, optimized for minimum cost, are summarized. The use of cellular glass as a reflective panel substrate material is shown to offer significant weight and cost advantages compared to existing technology materials.

Mitochondria in Lung Diseases

PubMed Central

Aravamudan, Bharathi; Thompson, Michael A.; Pabelick, Christina M.; Prakash, Y. S.

2014-01-01

Summary Mitochondria are autonomous cellular organelles that oversee a variety of functions such as metabolism, energy production, calcium buffering, and cell fate determination. Regulation of their morphology and diverse activities beyond energy production are being recognized as playing major roles in cellular health and dysfunction. This review is aimed at summarizing what is known regarding mitochondrial contributions to pathogenesis of lung diseases. Emphasis is given to understanding the importance of structural and functional aspects of mitochondria in both normal cellular function (based on knowledge from other cell types) and in development and modulation of lung diseases such as asthma, COPD, cystic fibrosis and cancer. Emerging techniques that allow examination of mitochondria, and potential strategies to target mitochondria in the treatment of lung diseases are also discussed. PMID:23978003

Total cellular glycomics allows characterizing cells and streamlining the discovery process for cellular biomarkers.

PubMed

Fujitani, Naoki; Furukawa, Jun-ichi; Araki, Kayo; Fujioka, Tsuyoshi; Takegawa, Yasuhiro; Piao, Jinhua; Nishioka, Taiki; Tamura, Tomohiro; Nikaido, Toshio; Ito, Makoto; Nakamura, Yukio; Shinohara, Yasuro

2013-02-05

Although many of the frequently used pluripotency biomarkers are glycoconjugates, a glycoconjugate-based exploration of novel cellular biomarkers has proven difficult due to technical difficulties. This study reports a unique approach for the systematic overview of all major classes of oligosaccharides in the cellular glycome. The proposed method enabled mass spectrometry-based structurally intensive analyses, both qualitatively and quantitatively, of cellular N- and O-linked glycans derived from glycoproteins, glycosaminoglycans, and glycosphingolipids, as well as free oligosaccharides of human embryonic stem cells (hESCs), induced pluripotent stem cells (hiPSCs), and various human cells derived from normal and carcinoma cells. Cellular total glycomes were found to be highly cell specific, demonstrating their utility as unique cellular descriptors. Structures of glycans of all classes specifically observed in hESCs and hiPSCs tended to be immature in general, suggesting the presence of stem cell-specific glycosylation spectra. The current analysis revealed the high similarity of the total cellular glycome between hESCs and hiPSCs, although it was suggested that hESCs are more homogeneous than hiPSCs from a glycomic standpoint. Notably, this study enabled a priori identification of known pluripotency biomarkers such as SSEA-3, -4, and -5 and Tra-1-60/81, as well as a panel of glycans specifically expressed by hESCs and hiPSCs.

Assessment of Mechanical Performance of Bone Architecture Using Rapid Prototyping Models

NASA Astrophysics Data System (ADS)

Saparin, Peter; Woesz, Alexander; Thomsen, Jasper S.; Fratzl, Peter

2008-06-01

The aim of this on-going research project is to assess the influence of bone microarchitecture on the mechanical performance of trabecular bone. A testing chain consist-ing of three steps was established: 1) micro computed tomography (μCT) imaging of human trabecular bone; 2) building of models of the bone from a light-sensitive polymer using Rapid Prototyping (RP); 3) mechanical testing of the models in a material testing machine. A direct resampling procedure was developed to convert μCT data into the format of the RP machine. Standardized parameters for production and testing of the plastic models were established by use of regular cellular structures. Next, normal, osteoporotic, and extreme osteoporotic vertebral trabecular bone architectures were re-produced by RP and compression tested. We found that normal architecture of vertebral trabecular bone exhibit behaviour characteristic of a cellular structure. In normal bone the fracture occurs at much higher strain values that in osteoporotic bone. After the fracture a normal trabecular architecture is able to carry much higher loads than an osteoporotic architecture. However, no statistically significant differences were found in maximal stress during uniaxial compression of the central part of normal, osteoporotic, and extreme osteoporotic vertebral trabecular bone. This supports the hypothesis that osteoporotic trabecular bone can compensate for a loss of trabeculae by thickening the remaining trabeculae in the loading direction (compensatory hypertrophy). The developed approach could be used for mechanical evaluation of structural data acquired non-invasively and assessment of changes in performance of bone architecture.

Cations Form Sequence Selective Motifs within DNA Grooves via a Combination of Cation-Pi and Ion-Dipole/Hydrogen Bond Interactions

PubMed Central

Stewart, Mikaela; Dunlap, Tori; Dourlain, Elizabeth; Grant, Bryce; McFail-Isom, Lori

2013-01-01

The fine conformational subtleties of DNA structure modulate many fundamental cellular processes including gene activation/repression, cellular division, and DNA repair. Most of these cellular processes rely on the conformational heterogeneity of specific DNA sequences. Factors including those structural characteristics inherent in the particular base sequence as well as those induced through interaction with solvent components combine to produce fine DNA structural variation including helical flexibility and conformation. Cation-pi interactions between solvent cations or their first hydration shell waters and the faces of DNA bases form sequence selectively and contribute to DNA structural heterogeneity. In this paper, we detect and characterize the binding patterns found in cation-pi interactions between solvent cations and DNA bases in a set of high resolution x-ray crystal structures. Specifically, we found that monovalent cations (Tl+) and the polarized first hydration shell waters of divalent cations (Mg2+, Ca2+) form cation-pi interactions with DNA bases stabilizing unstacked conformations. When these cation-pi interactions are combined with electrostatic interactions a pattern of specific binding motifs is formed within the grooves. PMID:23940752

Cations form sequence selective motifs within DNA grooves via a combination of cation-pi and ion-dipole/hydrogen bond interactions.

PubMed

Stewart, Mikaela; Dunlap, Tori; Dourlain, Elizabeth; Grant, Bryce; McFail-Isom, Lori

2013-01-01

The fine conformational subtleties of DNA structure modulate many fundamental cellular processes including gene activation/repression, cellular division, and DNA repair. Most of these cellular processes rely on the conformational heterogeneity of specific DNA sequences. Factors including those structural characteristics inherent in the particular base sequence as well as those induced through interaction with solvent components combine to produce fine DNA structural variation including helical flexibility and conformation. Cation-pi interactions between solvent cations or their first hydration shell waters and the faces of DNA bases form sequence selectively and contribute to DNA structural heterogeneity. In this paper, we detect and characterize the binding patterns found in cation-pi interactions between solvent cations and DNA bases in a set of high resolution x-ray crystal structures. Specifically, we found that monovalent cations (Tl⁺) and the polarized first hydration shell waters of divalent cations (Mg²⁺, Ca²⁺) form cation-pi interactions with DNA bases stabilizing unstacked conformations. When these cation-pi interactions are combined with electrostatic interactions a pattern of specific binding motifs is formed within the grooves.

Fidelity of DNA Replication in Normal and Malignant Human Brest Cells.

DTIC Science & Technology

1995-08-31

cellular DNA replication machinery, we have initiated experiments that utilize a multiprotein DNA replication complex (MRC) isolated from breast cancer...gene in an in vitro DNA replication assay. By utilizing the target gene in a bacterial mutant selection assay we have begun to determine the...frequency with which mutational sequence errors occur as a result of the in vitro DNA replication mediated by the breast cancer cell MRC and the normal breast

Deficiency of Huntingtin Has Pleiotropic Effects in the Social Amoeba Dictyostelium discoideum

PubMed Central

Myre, Michael A.; Lumsden, Amanda L.; Thompson, Morgan N.; Wasco, Wilma; MacDonald, Marcy E.; Gusella, James F.

2011-01-01

Huntingtin is a large HEAT repeat protein first identified in humans, where a polyglutamine tract expansion near the amino terminus causes a gain-of-function mechanism that leads to selective neuronal loss in Huntington's disease (HD). Genetic evidence in humans and knock-in mouse models suggests that this gain-of-function involves an increase or deregulation of some aspect of huntingtin's normal function(s), which remains poorly understood. As huntingtin shows evolutionary conservation, a powerful approach to discovering its normal biochemical role(s) is to study the effects caused by its deficiency in a model organism with a short life-cycle that comprises both cellular and multicellular developmental stages. To facilitate studies aimed at detailed knowledge of huntingtin's normal function(s), we generated a null mutant of hd, the HD ortholog in Dictyostelium discoideum. Dictyostelium cells lacking endogenous huntingtin were viable but during development did not exhibit the typical polarized morphology of Dictyostelium cells, streamed poorly to form aggregates by accretion rather than chemotaxis, showed disorganized F-actin staining, exhibited extreme sensitivity to hypoosmotic stress, and failed to form EDTA-resistant cell–cell contacts. Surprisingly, chemotactic streaming could be rescued in the presence of the bivalent cations Ca2+ or Mg2+ but not pulses of cAMP. Although hd − cells completed development, it was delayed and proceeded asynchronously, producing small fruiting bodies with round, defective spores that germinated spontaneously within a glassy sorus. When developed as chimeras with wild-type cells, hd − cells failed to populate the pre-spore region of the slug. In Dictyostelium, huntingtin deficiency is compatible with survival of the organism but renders cells sensitive to low osmolarity, which produces pleiotropic cell autonomous defects that affect cAMP signaling and as a consequence development. Thus, Dictyostelium provides a novel haploid organism model for genetic, cell biological, and biochemical studies to delineate the functions of the HD protein. PMID:21552328

A short history of diagnostic tests for von Willebrand disease: in memory of Barry Firkin (1930 to 2001) and Ted Zimmerman (1937 to 1988).

PubMed

Koutts, Jerry

2006-07-01

By the end of the 1960s, von Willebrand disease (vWD) was accepted as a combined deficiency of factor (F) VIII coagulation and a plasma factor responsible for normal platelet adhesion. Just how these two functions related to each other was unclear, and the diagnostic tests available at the time were poorly reproducible, cumbersome, and unreliable. As a consequence, the condition was poorly delineated from other coagulation and platelet disorders. In the early 1970s, ristocetin-induced platelet aggregation was described and formed the basis of the first consistent and reliable test that quantified the platelet adhesive function missing in vWD. Immunoprecipitating techniques specific for the molecule missing in vWD were defined. The application of these technologies allowed a clearer understanding of the heterogeneity of vWD and continues to form a basis for the diagnosis of this condition. Concurrently, exploration of the structure and function of von Willebrand factor (vWF) has contributed greatly to the understanding of platelet physiology, ligand receptor interaction, and pathways of cellular interaction and activation. Despite all of the progress during the last 35 years, including extensive developments in the field of molecular biology and genetics of vWD, the diagnosis of this condition in many, if not most cases, remains controversial. The final plasma level of vWF is influenced substantially by epigenetic and environmental factors. This natural heterogeneity is further compounded by significant imprecision of existing tests. As a consequence, defining vWD on the basis of a variation from the normal range alone is more than likely to be incorrect. The high frequency of a positive bleeding disorder in the normal population does not assist discrimination. It has been suggested that the diagnosis of mild type 1 vWD be discarded because it does not exhibit consistent linkage to the VWF gene and does not predict bleeding.

A magnetic-dependent protein corona of tailor-made superparamagnetic iron oxides alters their biological behaviors

NASA Astrophysics Data System (ADS)

Liu, Ziyao; Zhan, Xiaohui; Yang, Minggang; Yang, Qi; Xu, Xianghui; Lan, Fang; Wu, Yao; Gu, Zhongwei

2016-03-01

In recent years, it is becoming increasingly evident that once nanoparticles come into contact with biological fluids, a protein corona surely forms and critically affects the biological behaviors of nanoparticles. Herein, we investigate whether the formation of protein corona on the surface of superparamagnetic iron oxides (SPIOs) is influenced by static magnetic field. Under static magnetic field, there is no obvious variation in the total amount of protein adsorption, but the proportion of adsorbed proteins significantly changes. Noticeably, certain proteins including apolipoproteins, complement system proteins and acute phase proteins, increase in the protein corona of SPIOs in the magnetic field. More importantly, the magnetic-dependent protein corona of SPIOs enhances the cellular uptake of SPIOs into the normal cell line (3T3 cells) and tumor cell line (HepG2 cells), due to increased adsorption of apolipoprotein. In addition, SPIOs with the magnetic-dependent protein corona cause high cytotoxicity to 3T3 cells and HepG2 cells. This work discloses that superparamagnetism as a key feature of SPIOs affects the composition of protein corona to a large extent, which further alters the biological behaviors of SPIOs.In recent years, it is becoming increasingly evident that once nanoparticles come into contact with biological fluids, a protein corona surely forms and critically affects the biological behaviors of nanoparticles. Herein, we investigate whether the formation of protein corona on the surface of superparamagnetic iron oxides (SPIOs) is influenced by static magnetic field. Under static magnetic field, there is no obvious variation in the total amount of protein adsorption, but the proportion of adsorbed proteins significantly changes. Noticeably, certain proteins including apolipoproteins, complement system proteins and acute phase proteins, increase in the protein corona of SPIOs in the magnetic field. More importantly, the magnetic-dependent protein corona of SPIOs enhances the cellular uptake of SPIOs into the normal cell line (3T3 cells) and tumor cell line (HepG2 cells), due to increased adsorption of apolipoprotein. In addition, SPIOs with the magnetic-dependent protein corona cause high cytotoxicity to 3T3 cells and HepG2 cells. This work discloses that superparamagnetism as a key feature of SPIOs affects the composition of protein corona to a large extent, which further alters the biological behaviors of SPIOs. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr08447d

Cyclosporin A associated helicase-like protein facilitates the association of hepatitis C virus RNA polymerase with its cellular cyclophilin B.

PubMed

Morohashi, Kengo; Sahara, Hiroeki; Watashi, Koichi; Iwabata, Kazuki; Sunoki, Takashi; Kuramochi, Kouji; Takakusagi, Kaori; Miyashita, Hiroki; Sato, Noriyuki; Tanabe, Atsushi; Shimotohno, Kunitada; Kobayashi, Susumu; Sakaguchi, Kengo; Sugawara, Fumio

2011-04-29

Cyclosporin A (CsA) is well known as an immunosuppressive drug useful for allogeneic transplantation. It has been reported that CsA inhibits hepatitis C virus (HCV) genome replication, which indicates that cellular targets of CsA regulate the viral replication. However, the regulation mechanisms of HCV replication governed by CsA target proteins have not been fully understood. Here we show a chemical biology approach that elucidates a novel mechanism of HCV replication. We developed a phage display screening to investigate compound-peptide interaction and identified a novel cellular target molecule of CsA. This protein, named CsA associated helicase-like protein (CAHL), possessed RNA-dependent ATPase activity that was negated by treatment with CsA. The downregulation of CAHL in the cells resulted in a decrease of HCV genome replication. CAHL formed a complex with HCV-derived RNA polymerase NS5B and host-derived cyclophilin B (CyPB), known as a cellular cofactor for HCV replication, to regulate NS5B-CyPB interaction. We found a cellular factor, CAHL, as CsA associated helicase-like protein, which would form trimer complex with CyPB and NS5B of HCV. The strategy using a chemical compound and identifying its target molecule by our phage display analysis is useful to reveal a novel mechanism underlying cellular and viral physiology.

Giant viruses coexisted with the cellular ancestors and represent a distinct supergroup along with superkingdoms Archaea, Bacteria and Eukarya

PubMed Central

2012-01-01

Background The discovery of giant viruses with genome and physical size comparable to cellular organisms, remnants of protein translation machinery and virus-specific parasites (virophages) have raised intriguing questions about their origin. Evidence advocates for their inclusion into global phylogenomic studies and their consideration as a distinct and ancient form of life. Results Here we reconstruct phylogenies describing the evolution of proteomes and protein domain structures of cellular organisms and double-stranded DNA viruses with medium-to-very-large proteomes (giant viruses). Trees of proteomes define viruses as a ‘fourth supergroup’ along with superkingdoms Archaea, Bacteria, and Eukarya. Trees of domains indicate they have evolved via massive and primordial reductive evolutionary processes. The distribution of domain structures suggests giant viruses harbor a significant number of protein domains including those with no cellular representation. The genomic and structural diversity embedded in the viral proteomes is comparable to the cellular proteomes of organisms with parasitic lifestyles. Since viral domains are widespread among cellular species, we propose that viruses mediate gene transfer between cells and crucially enhance biodiversity. Conclusions Results call for a change in the way viruses are perceived. They likely represent a distinct form of life that either predated or coexisted with the last universal common ancestor (LUCA) and constitute a very crucial part of our planet’s biosphere. PMID:22920653

Characterization of a rare Unverricht-Lundborg disease mutation.

PubMed

Duarte, Ana Joana; Ribeiro, Diogo; Chaves, João; Amaral, Olga

2015-09-01

Cystatin B (CSTB) gene mutations cause Unverricht-Lundborg disease (ULD), a rare form of myoclonic epilepsy. The previous identification of a Portuguese patient, homozygous for a unique splicing defect (c.66G > A; p.Q22Q), provided awareness regarding the existence of variant forms of ULD. In this work we aimed at the characterization of this mutation at the population level and at the cellular level. The cellular fractionation studies here carried out showed mislocalization of the protein and add to the knowledge on this disease.

The cellular distribution of lignans in Tsuga heterophylla wood

Treesearch

R.l. Krahmer; Richard W. Hemingway; W.E. Hillis

1970-01-01

Western hemlock heartwood contains patches of tracheids with large amounts of cellular inclusions. Microscopic and chemical examination of the wood showed several types of deposits containing the lignans matairesinol, hydroxymatairesinol and conidendrin. The deposits, which were often relatively pure individual lignans, frequently assumed different physical forms and...

STAT proteins: from normal control of cellular events to tumorigenesis.

PubMed

Calò, Valentina; Migliavacca, Manuela; Bazan, Viviana; Macaluso, Marcella; Buscemi, Maria; Gebbia, Nicola; Russo, Antonio

2003-11-01

Signal transducers and activators of transcription (STAT) proteins comprise a family of transcription factors latent in the cytoplasm that participate in normal cellular events, such as differentiation, proliferation, cell survival, apoptosis, and angiogenesis following cytokine, growth factor, and hormone signaling. STATs are activated by tyrosine phosphorylation, which is normally a transient and tightly regulates process. Nevertheless, several constitutively activated STATs have been observed in a wide number of human cancer cell lines and primary tumors, including blood malignancies and solid neoplasias. STATs can be divided into two groups according to their specific functions. One is made up of STAT2, STAT4, and STAT6, which are activated by a small number of cytokines and play a distinct role in the development of T-cells and in IFNgamma signaling. The other group includes STAT1, STAT3, and STAT5, activated in different tissues by means of a series of ligands and involved in IFN signaling, development of the mammary gland, response to GH, and embriogenesis. This latter group of STATS plays an important role in controlling cell-cycle progression and apoptosis and thus contributes to oncogenesis. Although an increased expression of STAT1 has been observed in many human neoplasias, this molecule can be considered a potential tumor suppressor, since it plays an important role in growth arrest and in promoting apoptosis. On the other hand, STAT3 and 5 are considered as oncogenes, since they bring about the activation of cyclin D1, c-Myc, and bcl-xl expression, and are involved in promoting cell-cycle progression, cellular transformation, and in preventing apoptosis.

Fourier transform infra-red spectroscopic signatures for lung cells' epithelial mesenchymal transition: A preliminary report

NASA Astrophysics Data System (ADS)

Sarkar, Atasi; Sengupta, Sanghamitra; Mukherjee, Anirban; Chatterjee, Jyotirmoy

2017-02-01

Infra red (IR) spectral characterization can provide label-free cellular metabolic signatures of normal and diseased circumstances in a rapid and non-invasive manner. Present study endeavoured to enlist Fourier transform infra red (FTIR) spectroscopic signatures for lung normal and cancer cells during chemically induced epithelial mesenchymal transition (EMT) for which global metabolic dimension is not well reported yet. Occurrence of EMT was validated with morphological and immunocytochemical confirmation. Pre-processed spectral data was analyzed using ANOVA and principal component analysis-linear discriminant analysis (PCA-LDA). Significant differences observed in peak area corresponding to biochemical fingerprint (900-1800 cm- 1) and high wave-number (2800-3800 cm- 1) regions contributed to adequate PCA-LDA segregation of cells undergoing EMT. The findings were validated by re-analysis of data using another in-house built binary classifier namely vector valued regularized kernel approximation (VVRKFA), in order to understand EMT progression. To improve the classification accuracy, forward feature selection (FFS) tool was employed in extracting potent spectral signatures by eliminating undesirable noise. Gradual increase in classification accuracy with EMT progression of both cell types indicated prominence of the biochemical alterations. Rapid changes in cellular metabolome noted in cancer cells within first 24 h of EMT induction along with higher classification accuracy for cancer cell groups in comparison to normal cells might be attributed to inherent differences between them. Spectral features were suggestive of EMT triggered changes in nucleic acid, protein, lipid and bound water contents which can emerge as the useful markers to capture EMT related cellular characteristics.

The use of normal forms for analysing nonlinear mechanical vibrations

PubMed Central

Neild, Simon A.; Champneys, Alan R.; Wagg, David J.; Hill, Thomas L.; Cammarano, Andrea

2015-01-01

A historical introduction is given of the theory of normal forms for simplifying nonlinear dynamical systems close to resonances or bifurcation points. The specific focus is on mechanical vibration problems, described by finite degree-of-freedom second-order-in-time differential equations. A recent variant of the normal form method, that respects the specific structure of such models, is recalled. It is shown how this method can be placed within the context of the general theory of normal forms provided the damping and forcing terms are treated as unfolding parameters. The approach is contrasted to the alternative theory of nonlinear normal modes (NNMs) which is argued to be problematic in the presence of damping. The efficacy of the normal form method is illustrated on a model of the vibration of a taut cable, which is geometrically nonlinear. It is shown how the method is able to accurately predict NNM shapes and their bifurcations. PMID:26303917

Prenatal Alcohol Exposure Affects Progenitor Cell Numbers in Olfactory Bulbs and Dentate Gyrus of Vervet Monkeys.

PubMed

Burke, Mark W; Inyatkin, Alexey; Ptito, Maurice; Ervin, Frank R; Palmour, Roberta M

2016-10-27

Fetal alcohol exposure (FAE) alters hippocampal cell numbers in rodents and primates, and this may be due, in part, to a reduction in the number or migration of neuronal progenitor cells. The olfactory bulb exhibits substantial postnatal cellular proliferation and a rapid turnover of newly formed cells in the rostral migratory pathway, while production and migration of postnatal neurons into the dentate gyrus may be more complex. The relatively small size of the olfactory bulb, compared to the hippocampus, potentially makes this structure ideal for a rapid analysis. This study used the St. Kitts vervet monkey ( Chlorocebus sabeus ) to (1) investigate the normal developmental sequence of post-natal proliferation in the olfactory bulb and dentate gyrus and (2) determine the effects of naturalistic prenatal ethanol exposure on proliferation at three different ages (neonate, five months and two years). Using design-based stereology, we found an age-related decrease of actively proliferating cells in the olfactory bulb and dentate gyrus for both control and FAE groups. Furthermore, at the neonatal time point, the FAE group had fewer actively proliferating cells as compared to the control group. These data are unique with respect to fetal ethanol effects on progenitor proliferation in the primate brain and suggest that the olfactory bulb may be a useful structure for studies of cellular proliferation.

Oxidative Stress Promotes Peroxiredoxin Hyperoxidation and Attenuates Pro-survival Signaling in Aging Chondrocytes*

PubMed Central

Collins, John A.; Wood, Scott T.; Nelson, Kimberly J.; Rowe, Meredith A.; Carlson, Cathy S.; Chubinskaya, Susan; Poole, Leslie B.; Furdui, Cristina M.; Loeser, Richard F.

2016-01-01

Oxidative stress-mediated post-translational modifications of redox-sensitive proteins are postulated as a key mechanism underlying age-related cellular dysfunction and disease progression. Peroxiredoxins (PRX) are critical intracellular antioxidants that also regulate redox signaling events. Age-related osteoarthritis is a common form of arthritis that has been associated with mitochondrial dysfunction and oxidative stress. The objective of this study was to determine the effect of aging and oxidative stress on chondrocyte intracellular signaling, with a specific focus on oxidation of cytosolic PRX2 and mitochondrial PRX3. Menadione was used as a model to induce cellular oxidative stress. Compared with chondrocytes isolated from young adult humans, chondrocytes from older adults exhibited higher levels of PRX1–3 hyperoxidation basally and under conditions of oxidative stress. Peroxiredoxin hyperoxidation was associated with inhibition of pro-survival Akt signaling and stimulation of pro-death p38 signaling. These changes were prevented in cultured human chondrocytes by adenoviral expression of catalase targeted to the mitochondria (MCAT) and in cartilage explants from MCAT transgenic mice. Peroxiredoxin hyperoxidation was observed in situ in human cartilage sections from older adults and in osteoarthritic cartilage. MCAT transgenic mice exhibited less age-related osteoarthritis. These findings demonstrate that age-related oxidative stress can disrupt normal physiological signaling and contribute to osteoarthritis and suggest peroxiredoxin hyperoxidation as a potential mechanism. PMID:26797130

Hybrid biosynthetic gene therapy vector development and dual engineering capacity.

PubMed

Jones, Charles H; Ravikrishnan, Anitha; Chen, Mingfu; Reddinger, Ryan; Kamal Ahmadi, Mahmoud; Rane, Snehal; Hakansson, Anders P; Pfeifer, Blaine A

2014-08-26

Genetic vaccines offer a treatment opportunity based upon successful gene delivery to specific immune cell modulators. Driving the process is the vector chosen for gene cargo packaging and subsequent delivery to antigen-presenting cells (APCs) capable of triggering an immune cascade. As such, the delivery process must successfully navigate a series of requirements and obstacles associated with the chosen vector and target cell. In this work, we present the development and assessment of a hybrid gene delivery vector containing biological and biomaterial components. Each component was chosen to design and engineer gene delivery separately in a complimentary and fundamentally distinct fashion. A bacterial (Escherichia coli) inner core and a biomaterial [poly(beta-amino ester)]-coated outer surface allowed the simultaneous application of molecular biology and polymer chemistry to address barriers associated with APC gene delivery, which include cellular uptake and internalization, phagosomal escape, and intracellular cargo concentration. The approach combined and synergized normally disparate vector properties and tools, resulting in increased in vitro gene delivery beyond individual vector components or commercially available transfection agents. Furthermore, the hybrid device demonstrated a strong, efficient, and safe in vivo humoral immune response compared with traditional forms of antigen delivery. In summary, the flexibility, diversity, and potential of the hybrid design were developed and featured in this work as a platform for multivariate engineering at the vector and cellular scales for new applications in gene delivery immunotherapy.

Development of a wide-field fluorescence imaging system for evaluation of wound re-epithelialization

NASA Astrophysics Data System (ADS)

Franco, Walfre; Gutierrez-Herrera, Enoch; Purschke, Martin; Wang, Ying; Tam, Josh; Anderson, R. Rox; Doukas, Apostolos

2013-03-01

Normal skin barrier function depends on having a viable epidermis, an epithelial layer formed by keratinocytes. The transparent epidermis, which is less than a 100 mum thick, is nearly impossible to see. Thus, the clinical evaluation of re-epithelialization is difficult, which hinders selecting appropriate therapy for promoting wound healing. An imaging system was developed to evaluate epithelialization by detecting endogenous fluorescence emissions of cellular proliferation over a wide field of view. A custom-made 295 nm ultraviolet (UV) light source was used for excitation. Detection was done by integrating a near-UV camera with sensitivity down to 300 nm, a 12 mm quartz lens with iris and focus lock for the UV regime, and a fluorescence bandpass filter with 340 nm center wavelength. To demonstrate that changes in fluorescence are related to cellular processes, the epithelialization of a skin substitute was monitored in vitro. The skin substitute or construct was made by embedding microscopic live human skin tissue columns, 1 mm in diameter and spaced 1 mm apart, in acellular porcine dermis. Fluorescence emissions clearly delineate the extent of lateral surface migration of keratinocytes and the total surface covered by the new epithelium. The fluorescence image of new epidermis spatially correlates with the corresponding color image. A simple, user-friendly way of imaging the presence of skin epithelium would improve wound care in civilian burns, ulcers and surgeries.

Cell transformation and mutability of different genetic loci in mammalian cells by metabolically activated carcinogenic polycylic hydrocarbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huberman, E.

1977-01-01

Treatment of experimental animals with chemical carcinogens, including some polycyclic hydrocarbons, can result in the formation of malignant tumors. The process whereby some chemicals induce malignancy is as yet unknown. However, in a model system using mammalian cells in culture, it was possible to show that the chemical carcinogens induce malignant transformation rather than select for pre-existing tumor cells. In the process of the in vitro cell transformation, the normal cells, which have an oriented pattern of cell growth, a limited life-span in vitro, and are not tumorigenic, are converted into cells that have a hereditary random pattern of cellmore » growth, the ability to grow continuously in culture, and the ability to form tumors in vivo. This stable heritable phenotype of the transformed cells is similar to that of cells derived from spontaneous or experimentally induced tumors. Such stable heritable phenotype changes may arise from alteration in gene expression due to a somatic mutation after interaction of the carcinogen with cellular DNA. In the present experiments we have shown that metabolically activated carcinogenic polycyclic hydrocarbons which have been shown to bind to cellular DNA induce somatic mutations at different genetic loci in mammalian cells and that there is a relationship between the degree of mutant induction and the degree of carcinogenicity of the different hydrocarbons tested.« less

Mutations in human C2CD3 cause skeletal dysplasia and provide new insights into phenotypic and cellular consequences of altered C2CD3 function

PubMed Central

Cortés, Claudio R.; McInerney-Leo, Aideen M.; Vogel, Ida; Rondón Galeano, Maria C.; Leo, Paul J.; Harris, Jessica E.; Anderson, Lisa K.; Keith, Patricia A.; Brown, Matthew A.; Ramsing, Mette; Duncan, Emma L.; Zankl, Andreas; Wicking, Carol

2016-01-01

Ciliopathies are a group of genetic disorders caused by defective assembly or dysfunction of the primary cilium, a microtubule-based cellular organelle that plays a key role in developmental signalling. Ciliopathies are clinically grouped in a large number of overlapping disorders, including the orofaciodigital syndromes (OFDS), the short rib polydactyly syndromes and Jeune asphyxiating thoracic dystrophy. Recently, mutations in the gene encoding the centriolar protein C2CD3 have been described in two families with a new sub-type of OFDS (OFD14), with microcephaly and cerebral malformations. Here we describe a third family with novel compound heterozygous C2CD3 mutations in two fetuses with a different clinical presentation, dominated by skeletal dysplasia with no microcephaly. Analysis of fibroblast cultures derived from one of these fetuses revealed a reduced ability to form cilia, consistent with previous studies in C2cd3-mutant mouse and chicken cells. More detailed analyses support a role for C2CD3 in basal body maturation; but in contrast to previous mouse studies the normal recruitment of the distal appendage protein CEP164 suggests that this protein is not sufficient for efficient basal body maturation and subsequent axonemal extension in a C2CD3-defective background. PMID:27094867

BLM helicase facilitates RNA polymerase I-mediated ribosomal RNA transcription

PubMed Central

Grierson, Patrick M.; Lillard, Kate; Behbehani, Gregory K.; Combs, Kelly A.; Bhattacharyya, Saumitri; Acharya, Samir; Groden, Joanna

2012-01-01

Bloom's syndrome (BS) is an autosomal recessive disorder that is invariably characterized by severe growth retardation and cancer predisposition. The Bloom's syndrome helicase (BLM), mutations of which lead to BS, localizes to promyelocytic leukemia protein bodies and to the nucleolus of the cell, the site of RNA polymerase I-mediated ribosomal RNA (rRNA) transcription. rRNA transcription is fundamental for ribosome biogenesis and therefore protein synthesis, cellular growth and proliferation; its inhibition limits cellular growth and proliferation as well as bodily growth. We report that nucleolar BLM facilitates RNA polymerase I-mediated rRNA transcription. Immunofluorescence studies demonstrate the dependance of BLM nucleolar localization upon ongoing RNA polymerase I-mediated rRNA transcription. In vivo protein co-immunoprecipitation demonstrates that BLM interacts with RPA194, a subunit of RNA polymerase I. 3H-uridine pulse-chase assays demonstrate that BLM expression is required for efficient rRNA transcription. In vitro helicase assays demonstrate that BLM unwinds GC-rich rDNA-like substrates that form in the nucleolus and normally inhibit progression of the RNA polymerase I transcription complex. These studies suggest that nucleolar BLM modulates rDNA structures in association with RNA polymerase I to facilitate RNA polymerase I-mediated rRNA transcription. Given the intricate relationship between rDNA metabolism and growth, our data may help in understanding the etiology of proportional dwarfism in BS. PMID:22106380

BLM helicase facilitates RNA polymerase I-mediated ribosomal RNA transcription.

PubMed

Grierson, Patrick M; Lillard, Kate; Behbehani, Gregory K; Combs, Kelly A; Bhattacharyya, Saumitri; Acharya, Samir; Groden, Joanna

2012-03-01

Bloom's syndrome (BS) is an autosomal recessive disorder that is invariably characterized by severe growth retardation and cancer predisposition. The Bloom's syndrome helicase (BLM), mutations of which lead to BS, localizes to promyelocytic leukemia protein bodies and to the nucleolus of the cell, the site of RNA polymerase I-mediated ribosomal RNA (rRNA) transcription. rRNA transcription is fundamental for ribosome biogenesis and therefore protein synthesis, cellular growth and proliferation; its inhibition limits cellular growth and proliferation as well as bodily growth. We report that nucleolar BLM facilitates RNA polymerase I-mediated rRNA transcription. Immunofluorescence studies demonstrate the dependance of BLM nucleolar localization upon ongoing RNA polymerase I-mediated rRNA transcription. In vivo protein co-immunoprecipitation demonstrates that BLM interacts with RPA194, a subunit of RNA polymerase I. (3)H-uridine pulse-chase assays demonstrate that BLM expression is required for efficient rRNA transcription. In vitro helicase assays demonstrate that BLM unwinds GC-rich rDNA-like substrates that form in the nucleolus and normally inhibit progression of the RNA polymerase I transcription complex. These studies suggest that nucleolar BLM modulates rDNA structures in association with RNA polymerase I to facilitate RNA polymerase I-mediated rRNA transcription. Given the intricate relationship between rDNA metabolism and growth, our data may help in understanding the etiology of proportional dwarfism in BS.

Advancing neuroscience through epigenetics: molecular mechanisms of learning and memory.

PubMed

Molfese, David L

2011-01-01

Humans share 96% of our 30,000 genes with Chimpanzees. The 1,200 genes that differ appear at first glance insufficient to describe what makes us human and them apes. However, we are now discovering that the mechanisms that regulate how genes are expressed tell a much richer story than our DNA alone. Sections of our DNA are constantly being turned on or off, marked for easy access, or secluded and hidden away, all in response to ongoing cellular activity. In the brain, neurons encode information-in effect memories-at the cellular level. Yet while memories may last a lifetime, neurons are dynamic structures. Every protein in the synapse undergoes some form of turnover, some with half-lives of only hours. How can a memory persist beyond the lifetimes of its constitutive molecular building blocks? Epigenetics-changes in gene expression that do not alter the underlying DNA sequence-may be the answer. In this article, epigenetic mechanisms including DNA methylation and acetylation or methylation of the histone proteins that package DNA are described in the context of animal learning. Through the interaction of these modifications a "histone code" is emerging wherein individual memories leave unique memory traces at the molecular level with distinct time courses. A better understanding of these mechanisms has implications for treatment of memory disorders caused by normal aging or diseases including schizophrenia, Alzheimer's, depression, and drug addiction.

Investigation of the effect of rapid and slow external pH increases on Enterococcus faecalis biofilm grown on dentine.

PubMed

Stenhouse, M; Zilm, P; Ratnayake, J; Cathro, P

2018-01-11

Calcium hydroxide is a common endodontic medicament and has an antimicrobial effect by increasing the localized pH within the root canal. However, Enterococcus faecalis has shown some resistance to calcium hydroxide. A flow cell apparatus was used to grow an E. faecalis biofilm on dentine discs. Following 4 weeks growth in Todd Hewitt Broth, flow cells were exposed to either a rapid or slow increase to pH 11.5 or 12.5. Cellular viability was determined using serial plating and the number of colony-forming units was normalized against the cellular protein content. Scanning electron microscopy was carried out to qualitatively observe the effects of the different rates of pH increase. A significant difference in viability between the pH rapid and slow groups was not shown in this study. Compared with pH 11.5 solutions, pH 12.5 solutions were more effective at killing bacteria although some E. faecalis still survived. Enterococcus faecalis did not adapt and develop a greater resistance to high pH following a slow rise in pH compared with a rapid rise in pH. As expected, pH 12.5 was more effective in reducing bacterial numbers compared with pH 11.5 although E. faecalis was not completely eliminated. © 2018 Australian Dental Association.

Simulating Bone Loss in Microgravity Using Mathematical Formulations of Bone Remodeling

NASA Technical Reports Server (NTRS)

Pennline, James A.

2009-01-01

Most mathematical models of bone remodeling are used to simulate a specific bone disease, by disrupting the steady state or balance in the normal remodeling process, and to simulate a therapeutic strategy. In this work, the ability of a mathematical model of bone remodeling to simulate bone loss as a function of time under the conditions of microgravity is investigated. The model is formed by combining a previously developed set of biochemical, cellular dynamics, and mechanical stimulus equations in the literature with two newly proposed equations; one governing the rate of change of the area of cortical bone tissue in a cross section of a cylindrical section of bone and one governing the rate of change of calcium in the bone fluid. The mechanical stimulus comes from a simple model of stress due to a compressive force on a cylindrical section of bone which can be reduced to zero to mimic the effects of skeletal unloading in microgravity. The complete set of equations formed is a system of first order ordinary differential equations. The results of selected simulations are displayed and discussed. Limitations and deficiencies of the model are also discussed as well as suggestions for further research.

Yeast and Fungal Prions: Amyloid-Handling Systems, Amyloid Structure, and Prion Biology.

PubMed

Wickner, R B; Edskes, H K; Gorkovskiy, A; Bezsonov, E E; Stroobant, E E

2016-01-01

Yeast prions (infectious proteins) were discovered by their outré genetic properties and have become important models for an array of human prion and amyloid diseases. A single prion protein can become any of many distinct amyloid forms (called prion variants or strains), each of which is self-propagating, but with different biological properties (eg, lethal vs mild). The folded in-register parallel β sheet architecture of the yeast prion amyloids naturally suggests a mechanism by which prion variant information can be faithfully transmitted for many generations. The yeast prions rely on cellular chaperones for their propagation, but can be cured by various chaperone imbalances. The Btn2/Cur1 system normally cures most variants of the [URE3] prion that arise. Although most variants of the [PSI+] and [URE3] prions are toxic or lethal, some are mild in their effects. Even the most mild forms of these prions are rare in the wild, indicating that they too are detrimental to yeast. The beneficial [Het-s] prion of Podospora anserina poses an important contrast in its structure, biology, and evolution to the yeast prions characterized thus far. Copyright © 2016 Elsevier Inc. All rights reserved.

Amyloid fibrils: formation, replication, and physics behind them

NASA Astrophysics Data System (ADS)

Saric, Andela

The assembly of normally soluble proteins into long fibrils, known as amyloids, is associated with a range of pathologies, including Alzheimer's and Parkinson's diseases. A large number of structurally unrelated proteins form this type of fibrils, and we are in a pursuit of physical principles that underlie the amyloid formation and propagation. We show that small disorders oligomers, which are increasingly believed to be the prime cause for cellular toxicity, serve as nucleation centers for the fibril formation. We then relate experimentally measurable kinetic descriptors of amyloid aggregation to the microscopic mechanisms of the process. Once formed, amyloid fibrils can catalyse the formation of new oligomers and fibrils in a process that resembles self-replication. By combining simulations with biosensing and kinetic measurements of the aggregation of Alzheimer's A β peptide, we propose a mechanistic explanation for the self-replication of protein fibrils, and discuss its thermodynamic signature. Finally, we consider the design of possible inhibitors of the fibril self-replication process. Mechanistic understandings provided here not only have implications for future efforts to control pathological protein aggregation, but are also of interest for the rational assembly of bionanomaterials, where achieving and controlling self-replication is one of the unfulfilled goals.

Experimental investigation of active rib stitch knitted architecture for flow control applications

NASA Astrophysics Data System (ADS)

Abel, Julianna M.; Mane, Poorna; Pascoe, Benjamin; Luntz, Jonathan; Brei, Diann

2010-04-01

Actively manipulating flow characteristics around the wing can enhance the high-lift capability and reduce drag; thereby, increasing fuel economy, improving maneuverability and operation over diverse flight conditions which enables longer, more varied missions. Active knits, a novel class of cellular structural smart material actuator architectures created by continuous, interlocked loops of stranded active material, produce distributed actuation that can actively manipulate the local surface of the aircraft wing to improve flow characteristics. Rib stitch active knits actuate normal to the surface, producing span-wise discrete periodic arrays that can withstand aerodynamic forces while supplying the necessary displacement for flow control. This paper presents a preliminary experimental investigation of the pressuredisplacement actuation performance capabilities of a rib stitch active knit based upon shape memory alloy (SMA) wire. SMA rib stitch prototypes in both individual form and in stacked and nestled architectures were experimentally tested for their quasi-static load-displacement characteristics, verifying the parallel and series relationships of the architectural configurations. The various configurations tested demonstrated the potential of active knits to generate the required level of distributed surface displacements while under aerodynamic level loads for various forms of flow control.

A futile cycle, formed between two ATP-dependant gamma-glutamyl cycle enzymes, gamma-glutamyl cysteine synthetase and 5-oxoprolinase: the cause of cellular ATP depletion in nephrotic cystinosis?

PubMed

Kumar, Akhilesh; Bachhawat, Anand Kumar

2010-03-01

Cystinosis, an inherited disease caused by a defect in the lysosomal cystine transporter (CTNS), is characterized by renal proximal tubular dysfunction. Adenosine triphosphate (ATP) depletion appears to be a key event in the pathophysiology of the disease, even though the manner in which ATP depletion occurs is still a puzzle. We present a model that explains how a futile cycle that is generated between two ATP-utilizing enzymes of the gamma-glutamyl cycle leads to ATP depletion. The enzyme gamma-glutamyl cysteine synthetase (gamma-GCS), in the absence of cysteine, forms 5-oxoproline (instead of the normal substrate, gamma-glutamyl cysteine) and the 5-oxoproline is converted into glutamate by the ATP-dependant enzyme, 5-oxoprolinase. Thus, in cysteine-limiting conditions, glutamate is cycled back into glutamate via 5-oxoproline at the cost of two ATP molecules without production of glutathione and is the cause of the decreased levels of glutathione synthesis, as well as the ATP depletion observed in these cells. The model is also compatible with the differences seen in the human patients and the mouse model of cystinosis, where renal failure is not observed.

Does stress remove the HDAC brakes for the formation and persistence of long-term memory?

PubMed

White, André O; Wood, Marcelo A

2014-07-01

It has been known for numerous decades that gene expression is required for long-lasting forms of memory. In the past decade, the study of epigenetic mechanisms in memory processes has revealed yet another layer of complexity in the regulation of gene expression. Epigenetic mechanisms do not only provide complexity in the protein regulatory complexes that control coordinate transcription for specific cell function, but the epigenome encodes critical information that integrates experience and cellular history for specific cell functions as well. Thus, epigenetic mechanisms provide a unique mechanism of gene expression regulation for memory processes. This may be why critical negative regulators of gene expression, such as histone deacetylases (HDACs), have powerful effects on the formation and persistence of memory. For example, HDAC inhibition has been shown to transform a subthreshold learning event into robust long-term memory and also generate a form of long-term memory that persists beyond the point at which normal long-term memory fails. A key question that is explored in this review, from a learning and memory perspective, is whether stress-dependent signaling drives the formation and persistence of long-term memory via HDAC-dependent mechanisms. Copyright © 2013 Elsevier Inc. All rights reserved.

Hole hopping through tyrosine/tryptophan chains protects proteins from oxidative damage

PubMed Central

Gray, Harry B.; Winkler, Jay R.

2015-01-01

Living organisms have adapted to atmospheric dioxygen by exploiting its oxidizing power while protecting themselves against toxic side effects. Reactive oxygen and nitrogen species formed during oxidative stress, as well as high-potential reactive intermediates formed during enzymatic catalysis, could rapidly and irreversibly damage polypeptides were protective mechanisms not available. Chains of redox-active tyrosine and tryptophan residues can transport potentially damaging oxidizing equivalents (holes) away from fragile active sites and toward protein surfaces where they can be scavenged by cellular reductants. Precise positioning of these chains is required to provide effective protection without inhibiting normal function. A search of the structural database reveals that about one third of all proteins contain Tyr/Trp chains composed of three or more residues. Although these chains are distributed among all enzyme classes, they appear with greatest frequency in the oxidoreductases and hydrolases. Consistent with a redox-protective role, approximately half of the dioxygen-using oxidoreductases have Tyr/Trp chain lengths ≥3 residues. Among the hydrolases, long Tyr/Trp chains appear almost exclusively in the glycoside hydrolases. These chains likely are important for substrate binding and positioning, but a secondary redox role also is a possibility. PMID:26195784

Does stress remove the HDAC brakes for the formation and persistence of long-term memory?

PubMed Central

White, André O.; Wood, Marcelo A.

2013-01-01

It has been known for numerous decades that gene expression is required for long-lasting forms of memory. In the past decade, the study of epigenetic mechanisms in memory processes has revealed yet another layer of complexity in the regulation of gene expression. Epigenetic mechanisms do not only provide complexity in the protein regulatory complexes that control coordinate transcription for specific cell function, but the epigenome encodes critical information that integrates experience and cellular history for specific cell functions as well. Thus, epigenetic mechanisms provide a unique mechanism of gene expression regulation for memory processes. This may be why critical negative regulators of gene expression, such as histone deacetylases (HDACs), have powerful effects on the formation and persistence of memory. For example, HDAC inhibition has been shown to transform a subthreshold learning event into robust long-term memory and also generate a form of long-term memory that persists beyond the point at which normal long-term memory fails. A key question that is explored in this review, from a learning and memory perspective, is whether stress-dependent signaling drives the formation and persistence of long-term memory via HDAC-dependent mechanisms. PMID:24149059

A new treatment for human malignant melanoma targeting L-type amino acid transporter 1 (LAT1): A pilot study in a canine model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fukumoto, Shinya; Hanazono, Kiwamu; Fu, Dah-Renn

2013-09-13

Highlights: •LAT1 is highly expressed in tumors but at low levels in normal tissues. •We examine LAT1 expression and function in malignant melanoma (MM). •LAT1 expression in MM tissues and cell lines is higher than those in normal tissues. •LAT1 selective inhibitors inhibit amino acid uptake and cell growth in MM cells. •New chemotherapeutic protocols including LAT1 inhibitors are effective for treatment. -- Abstract: L-type amino acid transporter 1 (LAT1), an isoform of amino acid transport system L, transports branched or aromatic amino acids essential for fundamental cellular activities such as cellular growth, proliferation and maintenance. This amino acid transportermore » recently has received attention because of its preferential and up-regulated expression in a variety of human tumors in contrast to its limited distribution and low-level expression in normal tissues. In this study, we explored the feasibility of using LAT1 inhibitor as a new therapeutic agent for human malignant melanomas (MM) using canine spontaneous MM as a model for human MM. A comparative study of LAT expression was performed in 48 normal tissues, 25 MM tissues and five cell lines established from MM. The study observed LAT1 mRNA levels from MM tissues and cell lines that were significantly (P < 0.01) higher than in normal tissues. Additionally, MM with distant metastasis showed a higher expression than those without distant metastasis. Functional analysis of LAT1 was performed on one of the five cell lines, CMeC-1. [{sup 3}H]L-Leucine uptake and cellular growth activities in CMeC-1 were inhibited in a dose-dependent manner by selective LAT1 inhibitors (2-amino-2-norbornane-carboxylic acid, BCH and melphalan, LPM). Inhibitory growth activities of various conventional anti-cancer drugs, including carboplatin, cyclophosphamide, dacarbazine, doxorubicin, mitoxantrone, nimustine, vinblastine and vincristine, were significantly (P < 0.05) enhanced by combination use with BCH or LPM. These findings suggest that LAT1 could be a new therapeutic target for MM.« less

Cutting the brakes and flooring the gas: how TMEPAI turns TGF-β into a tumor promoter.

PubMed

Cichon, Magdalena A; Radisky, Derek C

2014-09-01

In normal or nonmalignant cells, TGF-β inhibits cellular proliferation through activation of the SMAD-dependent canonical signaling pathway. Recent findings demonstrate that the protein TMEPAI1 can block the cytostatic effects of the canonical TGF-β signaling pathway, while activating cellular proliferation through the noncanonical, SMAD-independent TGF-β signaling pathway. As TMEPAI1 shows increased expression in the poor prognosis basal and HER2 intrinsic subtypes of breast cancer, these findings point to a new avenue of targeted therapy with considerable therapeutic potential.

Hematopoiesis: an evolving paradigm for stem cell biology.

PubMed

Orkin, Stuart H; Zon, Leonard I

2008-02-22

Establishment and maintenance of the blood system relies on self-renewing hematopoietic stem cells (HSCs) that normally reside in small numbers in the bone marrow niche of adult mammals. This Review describes the developmental origins of HSCs and the molecular mechanisms that regulate lineage-specific differentiation. Studies of hematopoiesis provide critical insights of general relevance to other areas of stem cell biology including the role of cellular interactions in development and tissue homeostasis, lineage programming and reprogramming by transcription factors, and stage- and age-specific differences in cellular phenotypes.

Using Magnets and Magnetic Beads to Dissect Signaling Pathways Activated by Mechanical Tension Applied to Cells

PubMed Central

Marjoram, R.J.; Guilluy, C; Burridge, K.

2015-01-01

Cellular tension has implications in normal biology and pathology. Membrane adhesion receptors serve as conduits for mechanotransduction that lead to cellular responses. Ligand-conjugated magnetic beads are a useful tool in the study of how cells sense and respond to tension. Here we detail methods for their use in applying tension to cells and strategies for analyzing the results. We demonstrate the methods by analyzing mechanotransduction through VE-cadherin on endothelial cells using both permanent magnets and magnetic tweezers. PMID:26427549

Functional and phenotypic evaluation of eosinophils from patients with the acute form of paracoccidioidomycosis.

PubMed

Braga, Fernanda Gambogi; Ruas, Luciana Pereira; Pereira, Ricardo Mendes; Lima, Xinaida Taligare; Antunes, Edson; Mamoni, Ronei Luciano; Blotta, Maria Heloisa Souza Lima

2017-05-01

Eosinophilia is a typical finding of the acute/juvenile form of paracoccidioidomycosis (PCM), a systemic mycosis endemic in Latin America. This clinical form is characterized by depressed cellular immune response and production of Th2 cytokines. Moreover, it has been shown that the increased number of eosinophils in peripheral blood of patients returns to normal values after antifungal treatment. However, the role of eosinophils in PCM has never been evaluated. This study aimed to assess the phenotypic and functional characteristics of eosinophils in PCM. In 15 patients with the acute form of the disease, we detected expression of MBP, CCL5 (RANTES) and CCL11 (eotaxin) in biopsies of lymph nodes and liver. In addition, there were higher levels of chemokines and granule proteins in the peripheral blood of patients compared to controls. Isolation of eosinophils from blood revealed a higher frequency of CD69+ and TLR2+ eosinophils in patients compared to controls, and a lower population of CD80+ cells. We also evaluated the fungicidal capacity of eosinophils in vitro. Our results revealed that eosinophils from PCM patients and controls exhibit similar ability to kill P. brasiliensis yeast cells, although eosinophils of patients were less responsive to IL-5 stimulation than controls. In conclusion, we suggest that eosinophils might play a role in the host response to fungi and in the pathophysiology of PCM by inducing an intense and systemic inflammatory response in the initial phase of the infection.

The multifaceted functions of C/EBPα in normal and malignant haematopoiesis.

PubMed

Ohlsson, E; Schuster, M B; Hasemann, M; Porse, B T

2016-04-01

The process of blood formation, haematopoiesis, depends upon a small number of haematopoietic stem cells (HSCs) that reside in the bone marrow. Differentiation of HSCs is characterised by decreased expression of genes associated with self-renewal accompanied by a stepwise activation of genes promoting differentiation. Lineage branching is further directed by groups of cooperating and counteracting genes forming complex networks of lineage-specific transcription factors. Imbalances in such networks can result in blockage of differentiation, lineage reprogramming and malignant transformation. CCAAT/enhancer-binding protein-α (C/EBPα) was originally identified 30 years ago as a transcription factor that binds both promoter and enhancer regions. Most of the early work focused on the role of C/EBPα in regulating transcriptional processes as well as on its functions in key differentiation processes during liver, adipogenic and haematopoietic development. Specifically, C/EBPα was shown to control differentiation by its ability to coordinate transcriptional output with cell cycle progression. Later, its role as an important tumour suppressor, mainly in acute myeloid leukaemia (AML), was recognised and has been the focus of intense studies by a number of investigators. More recent work has revisited the role of C/EBPα in normal haematopoiesis, especially its function in HSCs, and also started to provide more mechanistic insights into its role in normal and malignant haematopoiesis. In particular, the differential actions of C/EBPα isoforms, as well as its importance in chromatin remodelling and cellular reprogramming, are beginning to be elucidated. Finally, recent work has also shed light on the dichotomous function of C/EBPα in AML by demonstrating its ability to act as both a tumour suppressor and promoter. In the present review, we will summarise the current knowledge on the functions of C/EBPα during normal and malignant haematopoiesis with special emphasis on the recent work.

Exocrine cell-derived microparticles in response to lipopolysaccharide promote endocrine dysfunction in cystic fibrosis.

PubMed

Constantinescu, Andrei Alexandru; Gleizes, Céline; Alhosin, Mahmoud; Yala, Elhassan; Zobairi, Fatiha; Leclercq, Alexandre; Stoian, Gheorghe; Mitrea, Ioan Liviu; Prévost, Gilles; Toti, Florence; Kessler, Laurence

2014-03-01

Diabetes in cystic fibrosis (CF) is a result of exocrine pancreas alteration followed by endocrine dysfunction at a later stage. Microparticles (MPs) are plasma membrane fragments shed from stimulated or damaged cells that act as cellular effectors. Our aim was to identify a new form of interaction between exocrine and endocrine pancreatic cells mediated by exocrine MPs, in the context of recurrent infection in CF. MPs from either human exocrine CFTRΔF508-mutated (CFPAC-1) cells or exocrine normal pancreatic (PANC-1) cells were collected after treatment by LPS from Pseudomonas aeruginosa and applied to rat endocrine normal insulin-secreting RIN-m5F cells. MP membrane integration in target cells was established by confocal microscopy and flow cytometry using PKH26 lipid probe. Apoptosis, lysosomal activity, insulin secretion were measured after 18 h. MP-mediated NF-κB activation was measured in HEK-Blue reporter cells by SEAP reporter gene system and in RIN-m5F cells by Western blot. In endocrine normal cells, CFTR inhibition was achieved using Inhibitor-172. Compared to PANC-1, MPs from CFPAC-1 significantly reduced insulin secretion and lysosomal activity in RIN-m5F. MPs induced NF-κB activation by increasing the level of IκB phosphorylation. Moreover, the inhibition of NF-κB activation using specific inhibitors was associated with a restored insulin secretion. Interestingly, CFTR inhibition in normal RIN-m5F cells promoted apoptosis and decreased insulin secretion. During recurrent infections associated with CF, exocrine MPs may contribute to endocrine cell dysfunction via NF-κB pathways. Membrane CFTR dysfunction is associated with decreased insulin secretion. © 2013. Published by Elsevier B.V. on behalf of European Cystic Fibrosis Society. All rights reserved.

Catch-up Growth: Cellular and Molecular Mechanisms

PubMed Central

Finkielstain, GP; Lui, JC; Baron, J

2012-01-01

In mammals, after a period of growth inhibition, body growth often does not just return to a normal rate but actually exceeds the normal rate, resulting in catch-up growth. Recent evidence suggests that catch-up growth occurs because growth-inhibiting conditions delay progression of the physiological mechanisms that normally cause body growth to slow and cease with age. As a result, following the period of growth inhibition, tissues retain a greater proliferative capacity than normal, and therefore grow more rapidly than normal for age. There is evidence that this mechanism contributes both to catch-up growth in terms of body length, which involves proliferation in the growth plate, and to catch-up growth in terms of organ mass, which involves proliferation in multiple non-skeletal tissues. PMID:23428687

Sequenza: allele-specific copy number and mutation profiles from tumor sequencing data.

PubMed

Favero, F; Joshi, T; Marquard, A M; Birkbak, N J; Krzystanek, M; Li, Q; Szallasi, Z; Eklund, A C

2015-01-01

Exome or whole-genome deep sequencing of tumor DNA along with paired normal DNA can potentially provide a detailed picture of the somatic mutations that characterize the tumor. However, analysis of such sequence data can be complicated by the presence of normal cells in the tumor specimen, by intratumor heterogeneity, and by the sheer size of the raw data. In particular, determination of copy number variations from exome sequencing data alone has proven difficult; thus, single nucleotide polymorphism (SNP) arrays have often been used for this task. Recently, algorithms to estimate absolute, but not allele-specific, copy number profiles from tumor sequencing data have been described. We developed Sequenza, a software package that uses paired tumor-normal DNA sequencing data to estimate tumor cellularity and ploidy, and to calculate allele-specific copy number profiles and mutation profiles. We applied Sequenza, as well as two previously published algorithms, to exome sequence data from 30 tumors from The Cancer Genome Atlas. We assessed the performance of these algorithms by comparing their results with those generated using matched SNP arrays and processed by the allele-specific copy number analysis of tumors (ASCAT) algorithm. Comparison between Sequenza/exome and SNP/ASCAT revealed strong correlation in cellularity (Pearson's r = 0.90) and ploidy estimates (r = 0.42, or r = 0.94 after manual inspecting alternative solutions). This performance was noticeably superior to previously published algorithms. In addition, in artificial data simulating normal-tumor admixtures, Sequenza detected the correct ploidy in samples with tumor content as low as 30%. The agreement between Sequenza and SNP array-based copy number profiles suggests that exome sequencing alone is sufficient not only for identifying small scale mutations but also for estimating cellularity and inferring DNA copy number aberrations. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology.

Intestinal absorption of water-soluble vitamins in health and disease.

PubMed

Said, Hamid M

2011-08-01

Our knowledge of the mechanisms and regulation of intestinal absorption of water-soluble vitamins under normal physiological conditions, and of the factors/conditions that affect and interfere with theses processes has been significantly expanded in recent years as a result of the availability of a host of valuable molecular/cellular tools. Although structurally and functionally unrelated, the water-soluble vitamins share the feature of being essential for normal cellular functions, growth and development, and that their deficiency leads to a variety of clinical abnormalities that range from anaemia to growth retardation and neurological disorders. Humans cannot synthesize water-soluble vitamins (with the exception of some endogenous synthesis of niacin) and must obtain these micronutrients from exogenous sources. Thus body homoeostasis of these micronutrients depends on their normal absorption in the intestine. Interference with absorption, which occurs in a variety of conditions (e.g. congenital defects in the digestive or absorptive system, intestinal disease/resection, drug interaction and chronic alcohol use), leads to the development of deficiency (and sub-optimal status) and results in clinical abnormalities. It is well established now that intestinal absorption of the water-soluble vitamins ascorbate, biotin, folate, niacin, pantothenic acid, pyridoxine, riboflavin and thiamin is via specific carrier-mediated processes. These processes are regulated by a variety of factors and conditions, and the regulation involves transcriptional and/or post-transcriptional mechanisms. Also well recognized now is the fact that the large intestine possesses specific and efficient uptake systems to absorb a number of water-soluble vitamins that are synthesized by the normal microflora. This source may contribute to total body vitamin nutrition, and especially towards the cellular nutrition and health of the local colonocytes. The present review aims to outline our current understanding of the mechanisms involved in intestinal absorption of water-soluble vitamins, their regulation, the cell biology of the carriers involved and the factors that negatively affect these absorptive events. © The Authors Journal compilation © 2011 Biochemical Society

Diffusion-weighted magnetic resonance imaging of uterine cervical cancer.

PubMed

Liu, Ying; Bai, Renju; Sun, Haoran; Liu, Haidong; Wang, Dehua

2009-01-01

To determine the feasibility of diffusion-weighted magnetic resonance (MR) imaging (DWI) of uterine cervical cancer and to investigate whether the apparent diffusion coefficient (ADC) values of cervical cancer differ from those of normal cervix and whether they could indicate the histologic type and the pathologic grade of tumor. Forty-two female patients with histopathologically proven uterine cervical cancer and 15 female patients with uterine leiomyomas underwent preoperative MR examinations using a 1.5-T clinical scanner (GE 1.5T Twin-Speed Infinity with Excite II scanner; GE Healthcare, Waukesha, Wis). Scanning sequences included T2-weighted fast spin-echo imaging, T2-weighted fast spin-echo with fat suppression imaging, T1-weighted spin-echo imaging, and DWI with diffusion factors of 0 and 1000 s/mm2. Parameters evaluated consisted of ADC values of uterine cervical cancer and normal cervix. Histologic specimens were stained with hematoxylin and eosin. The cellular densities of 32 uterine cervical cancers were calculated, which were regarded as the ratio of the total area of tumor cell nuclei divided by the area of sample image. Apparent diffusion coefficient value was statistically different (P = 0.000) between normal and cancerous tissue in the uterine cervix; the former one was (mean [SD], 1.50 [0.16]) x 10(-3) mm2/s, and the latter one was (0.88 [0.15]) x 10(-3) mm2/s. Apparent diffusion coefficient value of squamous carcinoma was statistically lower than that of adenocarcinoma (P = 0.040). The ADC value of uterine cervical cancer correlated negatively with cellular density (r = -0.711, P = 0.000) and the grading of tumor (r = -0.778, P = 0.000). Diffusion-weighted MR imaging has a potential ability to differentiate between normal and cancerous tissue in the uterine cervix, and it can indicate the histologic type of uterine cervical cancer as well. The ADC value of uterine cervical cancer represents tumor cellular density, thus providing a new method for evaluating the pathologic grading of tumor.

[Primary study on fluro [ 19F] berberine derivative for human hepatocellular carcinoma targetting in vitro].

PubMed

Zhang, Tong; Wu, Xiaoai; Cai, Huawei; Liang, Meng; Fan, Chengzhong

2017-04-01

[ 18 F]HX-01, a Fluorine-18 labeled berberine derivative, is a potential positron emission tomography (PET) tumor imaging agent, while [ 19 F]HX-01 is a nonradioactive reference substance with different energy state and has the same physical and chemical properties. In order to collect data for further study of [ 18 F]HX-01 PET imaging of hepatocellular carcinoma in vivo , this study compared the uptake of [ 19 F]HX-01 by human hepatocellular carcinoma and normal hepatocytes in vitro . The target compound, [ 19 F]HX-01, was synthesized in one step using berberrubine and 3-fluoropropyl 4-methylbenzenesulfonate. Cellular uptake and localization of [ 19 F]HX-01 were performed by a fluorescence microscope in human hepatocellular carcinoma HepG2, SMMC-7721 and human normal hepatocyte HL-7702. Cellular proliferation inhibition and cell cytotoxicity assay of the [ 19 F]HX-01 were conducted using cell counting kit-8 (CCK-8) on HepG2, SMMC-7721 and HL-7702 cells. Fluorescent microscopy showed that the combining ability of [ 19 F]HX-01 to the carcinoma SMMC-7721 and HepG2 was higher than that to the normal HL-7702. Cellular proliferation inhibition assay demonstrated that [ 19 F]HX-01 leaded to a dose-dependent inhibition on SMMC-7721, HepG2, and HL-7702 proliferation. Cell cytotoxicity assay presented that the cytotoxicity of [ 19 F]HX-01 to SMMC-7721 and HepG2 was obviously higher than that to HL-7702. This in vitro study showed that [ 19 F]HX-01 had a higher selectivity on human hepatocellular carcinoma cells (SMMC-7721, HepG2) but has less toxicity to normal hepatocytes (HL-7702). This could set up the idea that the radioactive reference substance [ 18 F]HX-01 may be worthy of further development as a potential molecular probe targeting human hepatocellular carcinoma using PET.

Intestinal absorption of water-soluble vitamins in health and disease

PubMed Central

Said, Hamid M.

2014-01-01

Our knowledge of the mechanisms and regulation of intestinal absorption of water-soluble vitamins under normal physiological conditions, and of the factors/conditions that affect and interfere with theses processes has been significantly expanded in recent years as a result of the availability of a host of valuable molecular/cellular tools. Although structurally and functionally unrelated, the water-soluble vitamins share the feature of being essential for normal cellular functions, growth and development, and that their deficiency leads to a variety of clinical abnormalities that range from anaemia to growth retardation and neurological disorders. Humans cannot synthesize water-soluble vitamins (with the exception of some endogenous synthesis of niacin) and must obtain these micronutrients from exogenous sources. Thus body homoeostasis of these micronutrients depends on their normal absorption in the intestine. Interference with absorption, which occurs in a variety of conditions (e.g. congenital defects in the digestive or absorptive system, intestinal disease/resection, drug interaction and chronic alcohol use), leads to the development of deficiency (and sub-optimal status) and results in clinical abnormalities. It is well established now that intestinal absorption of the water-soluble vitamins ascorbate, biotin, folate, niacin, pantothenic acid, pyridoxine, riboflavin and thiamin is via specific carrier-mediated processes. These processes are regulated by a variety of factors and conditions, and the regulation involves transcriptional and/or post-transcriptional mechanisms. Also well recognized now is the fact that the large intestine possesses specific and efficient uptake systems to absorb a number of water-soluble vitamins that are synthesized by the normal microflora. This source may contribute to total body vitamin nutrition, and especially towards the cellular nutrition and health of the local colonocytes. The present review aims to outline our current understanding of the mechanisms involved in intestinal absorption of water-soluble vitamins, their regulation, the cell biology of the carriers involved and the factors that negatively affect these absorptive events. PMID:21749321

Formalizing Knowledge in Multi-Scale Agent-Based Simulations

PubMed Central

Somogyi, Endre; Sluka, James P.; Glazier, James A.

2017-01-01

Multi-scale, agent-based simulations of cellular and tissue biology are increasingly common. These simulations combine and integrate a range of components from different domains. Simulations continuously create, destroy and reorganize constituent elements causing their interactions to dynamically change. For example, the multi-cellular tissue development process coordinates molecular, cellular and tissue scale objects with biochemical, biomechanical, spatial and behavioral processes to form a dynamic network. Different domain specific languages can describe these components in isolation, but cannot describe their interactions. No current programming language is designed to represent in human readable and reusable form the domain specific knowledge contained in these components and interactions. We present a new hybrid programming language paradigm that naturally expresses the complex multi-scale objects and dynamic interactions in a unified way and allows domain knowledge to be captured, searched, formalized, extracted and reused. PMID:29338063

Formalizing Knowledge in Multi-Scale Agent-Based Simulations.

PubMed

Somogyi, Endre; Sluka, James P; Glazier, James A

2016-10-01

Multi-scale, agent-based simulations of cellular and tissue biology are increasingly common. These simulations combine and integrate a range of components from different domains. Simulations continuously create, destroy and reorganize constituent elements causing their interactions to dynamically change. For example, the multi-cellular tissue development process coordinates molecular, cellular and tissue scale objects with biochemical, biomechanical, spatial and behavioral processes to form a dynamic network. Different domain specific languages can describe these components in isolation, but cannot describe their interactions. No current programming language is designed to represent in human readable and reusable form the domain specific knowledge contained in these components and interactions. We present a new hybrid programming language paradigm that naturally expresses the complex multi-scale objects and dynamic interactions in a unified way and allows domain knowledge to be captured, searched, formalized, extracted and reused.

Imaging of normal and pathologic joint synovium using nonlinear optical microscopy as a potential diagnostic tool

NASA Astrophysics Data System (ADS)

Tiwari, Nivedan; Chabra, Sanjay; Mehdi, Sheherbano; Sweet, Paula; Krasieva, Tatiana B.; Pool, Roy; Andrews, Brian; Peavy, George M.

2010-09-01

An estimated 1.3 million people in the United States suffer from rheumatoid arthritis (RA). RA causes profound changes in the synovial membrane of joints, and without early diagnosis and intervention, progresses to permanent alterations in joint structure and function. The purpose of this study is to determine if nonlinear optical microscopy (NLOM) can utilize the natural intrinsic fluorescence properties of tissue to generate images that would allow visualization of the structural and cellular composition of fresh, unfixed normal and pathologic synovial tissue. NLOM is performed on rabbit knee joint synovial samples using 730- and 800-nm excitation wavelengths. Less than 30 mW of excitation power delivered with a 40×, 0.8-NA water immersion objective is sufficient for the visualization of synovial structures to a maximum depth of 70 μm without tissue damage. NLOM imaging of normal and pathologic synovial tissue reveals the cellular structure, synoviocytes, adipocytes, collagen, vascular structures, and differential characteristics of inflammatory infiltrates without requiring tissue processing or staining. Further study to evaluate the ability of NLOM to assess the characteristics of pathologic synovial tissue and its potential role for the management of disease is warranted.

Vulnerability of Gastric Mucosa in Diabetic Rats, Its Pathogenesis and Amelioration by Cuminum cyminum

PubMed Central

Vador, N.; Jagtap, Aarti G.; Damle, Archana

2012-01-01

Various studies have indicated that peptic ulcers occurring during the course of diabetic state are more severe and often associated with complications such as gastrointestinal bleeding. This study is the first attempt to understand the pathogenesis of gastric ulcers occurring during the diabetic state considering alternate biochemical pathways using suitable markers and its amelioration by Cuminum cyminum. In this study, diabetic rats showed a progressive increase in the stomach advanced glycated end products formation, gastric mucosal tumour necrosis factor-α and Thiobarbituric acid reactive substances levels as compared to normal control (nondiabetic) rats. There was decrease in gastric mucosal content, antioxidant enzymes and cellular ATPase enzyme levels of diabetic gastric mucosa when compared to the normal control group. mRNA expression of epidermal growth factor was found to be significantly higher as compared to normal control animals. Further methanol extract of Cuminum cyminum treatment to diabetic animals caused a reduction in blood glucose, and ulcer score when compared to diabetic control rats. It significantly increased gastric mucus content, antioxidant status and cellular ATPase enzyme levels as compared to diabetic control animals. Methanol extract of Cuminum cyminum inhibited advanced glycated end products formation in vitro as well as in vivo. PMID:23716866

Rapamycin-induced oligomer formation system of FRB-FKBP fusion proteins.

PubMed

Inobe, Tomonao; Nukina, Nobuyuki

2016-07-01

Most proteins form larger protein complexes and perform multiple functions in the cell. Thus, artificial regulation of protein complex formation controls the cellular functions that involve protein complexes. Although several artificial dimerization systems have already been used for numerous applications in biomedical research, cellular protein complexes form not only simple dimers but also larger oligomers. In this study, we showed that fusion proteins comprising the induced heterodimer formation proteins FRB and FKBP formed various oligomers upon addition of rapamycin. By adjusting the configuration of fusion proteins, we succeeded in generating an inducible tetramer formation system. Proteins of interest also formed tetramers by fusing to the inducible tetramer formation system, which exhibits its utility in a broad range of biological applications. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Quantitative implementation of the endogenous molecular-cellular network hypothesis in hepatocellular carcinoma.

PubMed

Wang, Gaowei; Zhu, Xiaomei; Gu, Jianren; Ao, Ping

2014-06-06

A quantitative hypothesis for cancer genesis and progression-the endogenous molecular-cellular network hypothesis, intended to include both genetic and epigenetic causes of cancer-has been proposed recently. Using this hypothesis, here we address the molecular basis for maintaining normal liver and hepatocellular carcinoma (HCC), and the potential strategy to cure or relieve HCC. First, we elaborate the basic assumptions of the hypothesis and establish a core working network of HCC according to the hypothesis. Second, we quantify the working network by a nonlinear dynamical system. We show that the working network reproduces the main known features of normal liver and HCC at both the modular and molecular levels. Lastly, the validated working network reveals that (i) specific positive feedback loops are responsible for the maintenance of normal liver and HCC; (ii) inhibiting proliferation and inflammation-related positive feedback loops and simultaneously inducing a liver-specific positive feedback loop is predicated as a potential strategy to cure or relieve HCC; and (iii) the genesis and regression of HCC are asymmetric. In light of the characteristic properties of the nonlinear dynamical system, we demonstrate that positive feedback loops must exist as a simple and general molecular basis for the maintenance of heritable phenotypes, such as normal liver and HCC, and regulating the positive feedback loops directly or indirectly provides potential strategies to cure or relieve HCC.

Telocyte dynamics in psoriasis

PubMed Central

Manole, CG; Gherghiceanu, Mihaela; Simionescu, Olga

2015-01-01

The presence of telocytes (TCs) as distinct interstitial cells was previously documented in human dermis. TCs are interstitial cells completely different than dermal fibroblasts. TCs are interconnected in normal dermis in a 3D network and may be involved in skin homeostasis, remodelling, regeneration and repair. The number, distribution and ultrastructure of TCs were recently shown to be affected in systemic scleroderma. Psoriasis is a common inflammatory skin condition (estimated to affect about 0.1–11.8% of population), a keratinization disorder on a genetic background. In psoriasis, the dermis contribution to pathogenesis is frequently eclipsed by remarkable epidermal phenomena. Because of the particular distribution of TCs around blood vessels, we have investigated TCs in the dermis of patients with psoriasis vulgaris using immunohistochemistry (IHC), immunofluorescence (IF), and transmission electron microscopy (TEM). IHC and IF revealed that CD34/PDGFRα-positive TCs are present in human papillary dermis. More TCs were present in the dermis of uninvolved skin and treated skin than in psoriatic dermis. In uninvolved skin, TEM revealed TCs with typical ultrastructural features being involved in a 3D interstitial network in close vicinity to blood vessels in contact with immunoreactive cells in normal and treated skin. In contrast, the number of TCs was significantly decreased in psoriatic plaque. The remaining TCs demonstrated multiple degenerative features: apoptosis, membrane disintegration, cytoplasm fragmentation and nuclear extrusion. We also found changes in the phenotype of vascular smooth muscle cells in small blood vessels that lost the protective envelope formed by TCs. Therefore, impaired TCs could be a ‘missed’ trigger for the characteristic vascular pathology in psoriasis. Our data explain the mechanism of Auspitz’s sign, the most pathognomonic clinical sign of psoriasis vulgaris. This study offers new insights on the cellularity of psoriatic lesions and we suggest that TCs should be considered new cellular targets in forthcoming therapies. PMID:25991475

Hexavalent Chromium Causes the Oxidation of Thioredoxin in Human Bronchial Epithelial Cells

PubMed Central

Myers, Judith M.; Antholine, William E.; Myers, Charles R.

2008-01-01

Hexavalent chromium [Cr(VI)] species such as chromates are cytotoxic. Inhalational exposure is a primary concern in many Cr-related industries and their immediate environments, and bronchial epithelial cells are directly exposed to inhaled Cr(VI). Chromates are readily taken up by cells and are reduced to reactive Cr species which may also result in the generation of reactive oxygen species (ROS). The thioredoxin (Trx) system has a key role in the maintenance of cellular thiol redox balance and is essential for cell survival. Cells normally maintain the cytosolic (Trx1) and mitochondrial (Trx2) thioredoxins largely in the reduced state. Redox western blots were used to assess the redox status of the thioredoxins in normal human bronchial epithelial cells (BEAS-2B) incubated with soluble Na2CrO4 or insoluble ZnCrO4 for different periods of time. Both chromates caused a dose- and time-dependent oxidation of Trx2 and Trx1. Trx2 was more susceptible in that it could all be converted to the oxidized form, whereas a small amount of reduced Trx1 remained even after prolonged treatment with higher Cr concentrations. Only one of the dithiols, presumably the active site, of Trx1 was oxidized by Cr(VI). Cr(VI) did not cause significant GSH depletion or oxidation indicating that Trx oxidation does not result from a general oxidation of cellular thiols. With purified Trx and thioredoxin reductase (TrxR) in vitro, Cr(VI) also resulted in Trx oxidation. It was determined that purified TrxR has pronounced Cr(VI) reducing activity, so competition for electron flow from TrxR might impair its ability to reduce Trx. The in vitro data also suggested some direct redox interaction between Cr(VI) and Trx. The ability of Cr(VI) to cause Trx oxidation in cells could contribute to its cytotoxic effects, and could have important implications for cell survival, redox-sensitive cell signaling, and the cells' tolerance of other oxidant insults. PMID:18328613

High-Fat Diet-Induced Obesity Promotes Expansion of Bone Marrow Adipose Tissue and Impairs Skeletal Stem Cell Functions in Mice.

PubMed

Tencerova, Michaela; Figeac, Florence; Ditzel, Nicholas; Taipaleenmäki, Hanna; Nielsen, Tina Kamilla; Kassem, Moustapha

2018-06-01

Obesity represents a risk factor for development of insulin resistance and type 2 diabetes. In addition, it has been associated with increased adipocyte formation in the bone marrow (BM) along with increased risk for bone fragility fractures. However, little is known on the cellular mechanisms that link obesity, BM adiposity, and bone fragility. Thus, in an obesity intervention study in C57BL/6J mice fed with a high-fat diet (HFD) for 12 weeks, we investigated the molecular and cellular phenotype of bone marrow adipose tissue (BMAT), BM progenitor cells, and BM microenvironment in comparison to peripheral adipose tissue (AT). HFD decreased trabecular bone mass by 29%, cortical thickness by 5%, and increased BM adiposity by 184%. In contrast to peripheral AT, BMAT did not exhibit pro-inflammatory phenotype. BM progenitor cells isolated from HFD mice exhibited decreased mRNA levels of inflammatory genes (Tnfα, IL1β, Lcn2) and did not manifest an insulin resistant phenotype evidenced by normal levels of pAKT after insulin stimulation as well as normal levels of insulin signaling genes. In addition, BM progenitor cells manifested enhanced adipocyte differentiation in HFD condition. Thus, our data demonstrate that BMAT expansion in response to HFD exerts a deleterious effect on the skeleton. Continuous recruitment of progenitor cells to adipogenesis leads to progenitor cell exhaustion, decreased recruitment to osteoblastic cells, and decreased bone formation. In addition, the absence of insulin resistance and inflammation in the BM suggest that BMAT buffers extra energy in the form of triglycerides and thus plays a role in whole-body energy homeostasis. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.

Organoids with cancer stem cell-like properties secrete exosomes and HSP90 in a 3D nanoenvironment.

PubMed

Eguchi, Takanori; Sogawa, Chiharu; Okusha, Yuka; Uchibe, Kenta; Iinuma, Ryosuke; Ono, Kisho; Nakano, Keisuke; Murakami, Jun; Itoh, Manabu; Arai, Kazuya; Fujiwara, Toshifumi; Namba, Yuri; Murata, Yoshiki; Ohyama, Kazumi; Shimomura, Manami; Okamura, Hirohiko; Takigawa, Masaharu; Nakatsura, Tetsuya; Kozaki, Ken-Ichi; Okamoto, Kuniaki; Calderwood, Stuart K

2018-01-01

Ability to form cellular aggregations such as tumorspheres and spheroids have been used as a morphological marker of malignant cancer cells and in particular cancer stem cells (CSC). However, the common definition of the types of cellular aggregation formed by cancer cells has not been available. We examined morphologies of 67 cell lines cultured on three dimensional morphology enhancing NanoCulture Plates (NCP) and classified the types of cellular aggregates that form. Among the 67 cell lines, 49 cell lines formed spheres or spheroids, 8 cell lines formed grape-like aggregation (GLA), 8 cell lines formed other types of aggregation, and 3 cell lines formed monolayer sheets. Seven GLA-forming cell lines were derived from adenocarcinoma among the 8 lines. A neuroendocrine adenocarcinoma cell line PC-3 formed asymmetric GLA with ductal structures on the NCPs and rapidly growing asymmetric tumors that metastasized to lymph nodes in immunocompromised mice. In contrast, another adenocarcinoma cell line DU-145 formed spheroids in vitro and spheroid-like tumors in vivo that did not metastasize to lymph nodes until day 50 after transplantation. Culture in the 3D nanoenvironment and in a defined stem cell medium enabled the neuroendocrine adenocarcinoma cells to form slowly growing large organoids that expressed multiple stem cell markers, neuroendocrine markers, intercellular adhesion molecules, and oncogenes in vitro. In contrast, the more commonly used 2D serum-contained environment reduced intercellular adhesion and induced mesenchymal transition and promoted rapid growth of the cells. In addition, the 3D stemness nanoenvironment promoted secretion of HSP90 and EpCAM-exosomes, a marker of CSC phenotype, from the neuroendocrine organoids. These findings indicate that the NCP-based 3D environment enables cells to form stem cell tumoroids with multipotency and model more accurately the in vivo tumor status at the levels of morphology and gene expression.

Organoids with cancer stem cell-like properties secrete exosomes and HSP90 in a 3D nanoenvironment

PubMed Central

Okusha, Yuka; Uchibe, Kenta; Iinuma, Ryosuke; Ono, Kisho; Nakano, Keisuke; Murakami, Jun; Itoh, Manabu; Arai, Kazuya; Fujiwara, Toshifumi; Namba, Yuri; Murata, Yoshiki; Ohyama, Kazumi; Shimomura, Manami; Okamura, Hirohiko; Takigawa, Masaharu; Nakatsura, Tetsuya; Kozaki, Ken-ichi; Okamoto, Kuniaki; Calderwood, Stuart K.

2018-01-01

Ability to form cellular aggregations such as tumorspheres and spheroids have been used as a morphological marker of malignant cancer cells and in particular cancer stem cells (CSC). However, the common definition of the types of cellular aggregation formed by cancer cells has not been available. We examined morphologies of 67 cell lines cultured on three dimensional morphology enhancing NanoCulture Plates (NCP) and classified the types of cellular aggregates that form. Among the 67 cell lines, 49 cell lines formed spheres or spheroids, 8 cell lines formed grape-like aggregation (GLA), 8 cell lines formed other types of aggregation, and 3 cell lines formed monolayer sheets. Seven GLA-forming cell lines were derived from adenocarcinoma among the 8 lines. A neuroendocrine adenocarcinoma cell line PC-3 formed asymmetric GLA with ductal structures on the NCPs and rapidly growing asymmetric tumors that metastasized to lymph nodes in immunocompromised mice. In contrast, another adenocarcinoma cell line DU-145 formed spheroids in vitro and spheroid-like tumors in vivo that did not metastasize to lymph nodes until day 50 after transplantation. Culture in the 3D nanoenvironment and in a defined stem cell medium enabled the neuroendocrine adenocarcinoma cells to form slowly growing large organoids that expressed multiple stem cell markers, neuroendocrine markers, intercellular adhesion molecules, and oncogenes in vitro. In contrast, the more commonly used 2D serum-contained environment reduced intercellular adhesion and induced mesenchymal transition and promoted rapid growth of the cells. In addition, the 3D stemness nanoenvironment promoted secretion of HSP90 and EpCAM-exosomes, a marker of CSC phenotype, from the neuroendocrine organoids. These findings indicate that the NCP-based 3D environment enables cells to form stem cell tumoroids with multipotency and model more accurately the in vivo tumor status at the levels of morphology and gene expression. PMID:29415026

Myeloperoxidase: a front-line defender against phagocytosed microorganisms

PubMed Central

Klebanoff, Seymour J.; Kettle, Anthony J.; Rosen, Henry; Winterbourn, Christine C.; Nauseef, William M.

2013-01-01

Successful immune defense requires integration of multiple effector systems to match the diverse virulence properties that members of the microbial world might express as they initiate and promote infection. Human neutrophils—the first cellular responders to invading microbes—exert most of their antimicrobial activity in phagosomes, specialized membrane-bound intracellular compartments formed by ingestion of microorganisms. The toxins generated de novo by the phagocyte NADPH oxidase and delivered by fusion of neutrophil granules with nascent phagosomes create conditions that kill and degrade ingested microbes. Antimicrobial activity reflects multiple and complex synergies among the phagosomal contents, and optimal action relies on oxidants generated in the presence of MPO. The absence of life-threatening infectious complications in individuals with MPO deficiency is frequently offered as evidence that the MPO oxidant system is ancillary rather than essential for neutrophil-mediated antimicrobial activity. However, that argument fails to consider observations from humans and KO mice that demonstrate that microbial killing by MPO-deficient cells is less efficient than that of normal neutrophils. We present evidence in support of MPO as a major arm of oxidative killing by neutrophils and propose that the essential contribution of MPO to normal innate host defense is manifest only when exposure to pathogens overwhelms the capacity of other host defense mechanisms. PMID:23066164

Addiction and the brain antireward system.

PubMed

Koob, George F; Le Moal, Michel

2008-01-01

A neurobiological model of the brain emotional systems has been proposed to explain the persistent changes in motivation that are associated with vulnerability to relapse in addiction, and this model may generalize to other psychopathology associated with dysregulated motivational systems. In this framework, addiction is conceptualized as a cycle of decreased function of brain reward systems and recruitment of antireward systems that progressively worsen, resulting in the compulsive use of drugs. Counteradaptive processes, such as opponent process, that are part of the normal homeostatic limitation of reward function fail to return within the normal homeostatic range and are hypothesized to repeatedly drive the allostatic state. Excessive drug taking thus results in not only the short-term amelioration of the reward deficit but also suppression of the antireward system. However, in the long term, there is worsening of the underlying neurochemical dysregulations that ultimately form an allostatic state (decreased dopamine and opioid peptide function, increased corticotropin-releasing factor activity). This allostatic state is hypothesized to be reflected in a chronic deviation of reward set point that is fueled not only by dysregulation of reward circuits per se but also by recruitment of brain and hormonal stress responses. Vulnerability to addiction may involve genetic comorbidity and developmental factors at the molecular, cellular, or neurocircuitry levels that sensitize the brain antireward systems.

Photodynamic diagnosis of bladder cancer in ex vivo urine cytology

NASA Astrophysics Data System (ADS)

Fu, C. Y.; Ng, B. K.; Razul, S. Gulam; Olivo, Malini C.; Lau, Weber K. O.; Tan, P. H.; Chin, William

2006-02-01

Bladder cancer is the fourth common malignant disease worldwide, accounting for 4% of all cancer cases. In Singapore, it is the ninth most common form of cancer. The high mortality rate can be reduced by early treatment following precancerous screening. Currently, the gold standard for screening bladder tumors is histological examination of biopsy specimen, which is both invasive and time-consuming. In this study ex vivo urine fluorescence cytology is investigated to offer a timely and biopsy-free means for detecting bladder cancers. Sediments in patients' urine samples were extracted and incubated with a novel photosensitizer, hypericin. Laser confocal microscopy was used to capture the fluorescence images at an excitation wavelength of 488 nm. Images were subsequently processed to single out the exfoliated bladder cells from the other cells based on the cellular size. Intensity histogram of each targeted cell was plotted and feature vectors, derived from the histogram moments, were used to represent each sample. A difference in the distribution of the feature vectors of normal and low-grade cancerous bladder cells was observed. Diagnostic algorithm for discriminating between normal and low-grade cancerous cells is elucidated in this paper. This study suggests that the fluorescence intensity profiles of hypericin in bladder cells can potentially provide an automated quantitative means of early bladder cancer diagnosis.

Roles of Specific Membrane Lipid Domains in EGF Receptor Activation and Cell Adhesion Molecule Stabilization in a Developing Olfactory System

PubMed Central

Gibson, Nicholas J.; Tolbert, Leslie P.; Oland, Lynne A.

2009-01-01

Background Reciprocal interactions between glial cells and olfactory receptor neurons (ORNs) cause ORN axons entering the brain to sort, to fasciculate into bundles destined for specific glomeruli, and to form stable protoglomeruli in the developing olfactory system of an experimentally advantageous animal species, the moth Manduca sexta. Epidermal growth factor receptors (EGFRs) and the cell adhesion molecules (IgCAMs) neuroglian and fasciclin II are known to be important players in these processes. Methodology/Principal Findings We report in situ and cell-culture studies that suggest a role for glycosphingolipid-rich membrane subdomains in neuron-glia interactions. Disruption of these subdomains by the use of methyl-β-cyclodextrin results in loss of EGFR activation, depletion of fasciclin II in ORN axons, and loss of neuroglian stabilization in the membrane. At the cellular level, disruption leads to aberrant ORN axon trajectories, small antennal lobes, abnormal arrays of olfactory glomerul, and loss of normal glial cell migration. Conclusions/Significance We propose that glycosphingolipid-rich membrane subdomains (possible membrane rafts or platforms) are essential for IgCAM-mediated EGFR activation and for anchoring of neuroglian to the cytoskeleton, both required for normal extension and sorting of ORN axons. PMID:19787046

S179D prolactin diminishes the effects of UV light on epidermal gamma delta T cells

PubMed Central

Guzmán, Esther A.; Langowski, John L.; De Guzman, Ariel; Konrad Muller, H.; Walker, Ameae M.; Owen, Laurie B.

2008-01-01

Epidermal gamma delta T cells (γδ T) and Langerhans cells (LC) are immune cells altered by exposure to ultraviolet radiation (UVB), a powerful stressor resulting in immune suppression. Prolactin (PRL) has been characterized as an immunomodulator, particularly during stress. In this study, we have asked whether separate administration of the two major forms of prolactin, unmodified and phosphorylated, to groups of 15 mice (3 experiments, each with 5 mice per treatment group) affected the number and morphology of these epidermal immune cells under control conditions, and following UV irradiation. Under control conditions, both PRLs reduced the number of γδ T, but a molecular mimic of phosphorylated PRL (S179D PRL) was more effective, resulting in a 30% reduction. In the irradiated group, however, S179D PRL was protective against a UV-induced reduction in γδ T number and change in morphology (halved the reduction and normalized the morphology). In addition, S179D PRL, but not unmodified (U-PRL), maintained a normal LC: γδ T ratio and sustained the dendritic morphology of LC after UV exposure. These findings suggest that S179D PRL may have an overall protective effect, countering UV-induced cellular alterations in the epidermis. PMID:17945411

FGF-23 in fibrous dysplasia of bone and its relationship to renal phosphate wasting

PubMed Central

Riminucci, Mara; Collins, Michael T.; Fedarko, Neal S.; Cherman, Natasha; Corsi, Alessandro; White, Kenneth E.; Waguespack, Steven; Gupta, Anurag; Hannon, Tamara; Econs, Michael J.; Bianco, Paolo; Gehron Robey, Pamela

2003-01-01

FGF-23, a novel member of the FGF family, is the product of the gene mutated in autosomal dominant hypophosphatemic rickets (ADHR). FGF-23 has been proposed as a circulating factor causing renal phosphate wasting not only in ADHR (as a result of inadequate degradation), but also in tumor-induced osteomalacia (as a result of excess synthesis by tumor cells). Renal phosphate wasting occurs in approximately 50% of patients with McCune-Albright syndrome (MAS) and fibrous dysplasia of bone (FD), which result from postzygotic mutations of the GNAS1 gene. We found that FGF-23 is produced by normal and FD osteoprogenitors and bone-forming cells in vivo and in vitro. In situ hybridization analysis of FGF-23 mRNA expression identified “fibrous” cells, osteogenic cells, and cells associated with microvascular walls as specific cellular sources of FGF-23 in FD. Serum levels of FGF-23 were increased in FD/MAS patients compared with normal age-matched controls and significantly higher in FD/MAS patients with renal phosphate wasting compared with those without, and correlated with disease burden bone turnover markers commonly used to assess disease activity. Production of FGF-23 by FD tissue may play an important role in the renal phosphate–wasting syndrome associated with FD/MAS. PMID:12952917

Differential changes in Substance P, VIP as well as neprilysin levels in patients with gastritis or ulcer.

PubMed

Erin, Nuray; Türker, Sema; Elpek, Ozlem; Yıldırım, Bülent

2012-06-01

The protective effect of capsaicin-sensitive sensory nerve (CSSN) activation was recently demonstrated in human gastric mucosa. We here examined changes in neuropeptides, specifically Substance P (SP), calcitonin-gene related peptide (CGRP) and vasoactive intestinal peptide (VIP) in patients with chronic gastritis or ulcer. Furthermore changes in neprilysin levels, which hydrolyse these neuropeptides, were determined. Gastric biopsies were obtained from both lesion- and normal-appearing mucosa of 57 patients. The presence of H. pylori infection was verified with rapid urease assay. Neuronal and non-neuronal levels of SP, VIP, CGRP and neprilysin activity were determined in freshly frozen biopsies. Immunohistochemical localization of neprilysin was performed in 30 paraffin embedded specimens. We here found that neuronal SP levels decreased significantly in normally appearing mucosa of patients with gastritis while levels of non-neuronal SP increased in diseased areas of gastritis and ulcer. The presence of H. pylori led to further decreases of SP levels. The content of VIP in both disease-involved and uninvolved mucosa, and expression of neprilysin, markedly decreased in patients with gastritis or ulcer. Since VIP, as well as SP fragments, formed following hydrolysis with neprilysin is recognized to have gastroprotective effects, decreased levels of VIP, SP and neprilysin may predispose to cellular damage. Copyright © 2012 Elsevier Inc. All rights reserved.

Septin9 is involved in septin filament formation and cellular stability.

PubMed

Füchtbauer, Annette; Lassen, Louise B; Jensen, Astrid B; Howard, Jennifer; Quiroga, Adán de Salas; Warming, Søren; Sørensen, Annette B; Pedersen, Finn S; Füchtbauer, Ernst-Martin

2011-08-01

Septin9 (Sept9) is a member of the filament-forming septin family of structural proteins and is associated with a variety of cancers and with hereditary neuralgic amyotrophy. We have generated mice with constitutive and conditional Sept9 knockout alleles. Homozygous deletion of Sept9 results in embryonic lethality around day 10 of gestation whereas mice homozygous for the conditional allele develop normally. Here we report the consequences of homozygous loss of Sept9 in immortalized murine embryonic fibroblasts. Proliferation rate was not changed but cells without Sept9 had an altered morphology compared to normal cells, particularly under low serum stress. Abnormal, fragmented, and multiple nuclei were more frequent in cells without Sept9. Cell migration, as measured by gap-filling and filter-invasion assays, was impaired, but individual cells did not move less than wild-type cells. Sept9 knockout cells showed a reduced resistance to hypo-osmotic stress. Stress fiber and vinculin staining at focal adhesion points was less prominent. Long septin filaments stained for Sept7 disappeared. Instead, staining was found in short, often curved filaments and rings. Furthermore, Sept7 was no longer localized to the mitotic spindle. Together, these data reveal the importance of Sept9 for septin filament formation and general cell stability.

Defending the mitochondria: The pathways of mitophagy and mitochondrial-derived vesicles.

PubMed

Roberts, Rosalind F; Tang, Matthew Y; Fon, Edward A; Durcan, Thomas M

2016-10-01

Mitochondria are the powerhouses for the cell, consuming oxygen to generate sufficient energy for the maintenance of normal cellular processes. However, a deleterious consequence of this process are reactive oxygen species generated as side-products of these reactions. As a means to protect mitochondria from damage, cells and mitochondria have developed a wide-range of mitochondrial quality control mechanisms that remove damaged mitochondrial cargo, enabling the mitochondria to repair the damage and ultimately restore their normal function. If the damage is extensive and mitochondria can no longer be repaired, a process termed mitophagy is initiated in which the mitochondria are directed for autophagic clearance. Canonical mitophagy is regulated by two proteins, PINK1 and Parkin, which are mutated in familial forms of Parkinson's disease. In this review, we discuss recent work elucidating the mechanism of PINK1/Parkin-mediated mitophagy, along with recently uncovered PINK1/Parkin-independent mitophagy pathways. Moreover, we describe a novel mitochondrial quality control pathway, involving mitochondrial-derived vesicles that direct distinct and damaged mitochondrial cargo for degradation in the lysosome. Finally, we discuss the association between mitochondrial quality control, cardiac, hepatic and neurodegenerative disease and discuss the possibility of targeting these pathways for therapeutic purposes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Disinfectants and Prions

USDA-ARS?s Scientific Manuscript database

Prions are novel pathogens that are believed to be composed solely of protein. They are capable of converting a normal cellular protein into the infectious isoform and thereby propagating an infection. Prion infections are characterized by a long asymptomatic incubation period followed by a relative...

Prostate-Specific Natural Health Products (Dietary Supplements) Radiosensitize Normal Prostate Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasan, Yasmin; Schoenherr, Diane; Martinez, Alvaro A.

Purpose: Prostate-specific health products (dietary supplements) are taken by cancer patients to alleviate the symptoms linked with poor prostate health. However, the effect of these agents on evidence-based radiotherapy practice is poorly understood. The present study aimed to determine whether dietary supplements radiosensitized normal prostate or prostate cancer cell lines. Methods and Materials: Three well-known prostate-specific dietary supplements were purchased from commercial sources available to patients (Trinovin, Provelex, and Prostate Rx). The cells used in the study included normal prostate lines (RWPE-1 and PWR-1E), prostate tumor lines (PC3, DU145, and LNCaP), and a normal nonprostate line (HaCaT). Supplement toxicity wasmore » assessed using cell proliferation assays [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and cellular radiosensitivity using conventional clonogenic assays (0.5-4Gy). Cell cycle kinetics were assessed using the bromodeoxyuridine/propidium iodide pulse-labeling technique, apoptosis by scoring caspase-3 activation, and DNA repair by assessing gammaH2AX. Results: The cell growth and radiosensitivity of the malignant PC3, DU145, and LNcaP cells were not affected by any of the dietary prostate supplements (Provelex [2mug/mL], Trinovin [10mug/mL], and Prostate Rx [50 mug/mL]). However, both Trinovin (10mug/mL) and Prostate Rx (6mug/mL) inhibited the growth rate of the normal prostate cell lines. Prostate Rx increased cellular radiosensitivity of RWPE-1 cells through the inhibition of DNA repair. Conclusion: The use of prostate-specific dietary supplements should be discouraged during radiotherapy owing to the preferential radiosensitization of normal prostate cells.« less

Estrogens and human papilloma virus oncogenes regulate human ether-à-go-go-1 potassium channel expression.

PubMed

Díaz, Lorenza; Ceja-Ochoa, Irais; Restrepo-Angulo, Iván; Larrea, Fernando; Avila-Chávez, Euclides; García-Becerra, Rocío; Borja-Cacho, Elizabeth; Barrera, David; Ahumada, Elías; Gariglio, Patricio; Alvarez-Rios, Elizabeth; Ocadiz-Delgado, Rodolfo; Garcia-Villa, Enrique; Hernández-Gallegos, Elizabeth; Camacho-Arroyo, Ignacio; Morales, Angélica; Ordaz-Rosado, David; García-Latorre, Ethel; Escamilla, Juan; Sánchez-Peña, Luz Carmen; Saqui-Salces, Milena; Gamboa-Dominguez, Armando; Vera, Eunice; Uribe-Ramírez, Marisela; Murbartián, Janet; Ortiz, Cindy Sharon; Rivera-Guevara, Claudia; De Vizcaya-Ruiz, Andrea; Camacho, Javier

2009-04-15

Ether-à-go-go-1 (Eag1) potassium channels are potential tools for detection and therapy of numerous cancers. Here, we show human Eag1 (hEag1) regulation by cancer-associated factors. We studied hEag1 gene expression and its regulation by estradiol, antiestrogens, and human papillomavirus (HPV) oncogenes (E6/E7). Primary cultures from normal placentas and cervical cancer tissues; tumor cell lines from cervix, choriocarcinoma, keratinocytes, and lung; and normal cell lines from vascular endothelium, keratinocytes, and lung were used. Reverse transcription-PCR (RT-PCR) experiments and Southern blot analysis showed Eag1 expression in all of the cancer cell types, normal trophoblasts, and vascular endothelium, in contrast to normal keratinocytes and lung cells. Estradiol and antiestrogens regulated Eag1 in a cell type-dependent manner. Real-time RT-PCR experiments in HeLa cells showed that Eag1 estrogenic regulation was strongly associated with the expression of estrogen receptor-alpha. Eag1 protein was detected by monoclonal antibodies in normal placenta and placental blood vessels. Patch-clamp recordings in normal trophoblasts treated with estradiol exhibited potassium currents resembling Eag1 channel activity. Eag1 gene expression in keratinocytes depended either on cellular immortalization or the presence of HPV oncogenes. Eag1 protein was found in keratinocytes transfected with E6/E7 HPV oncogenes. Cell proliferation of E6/E7 keratinocytes was decreased by Eag1 antibodies inhibiting channel activity and by the nonspecific Eag1 inhibitors imipramine and astemizole; the latter also increased apoptosis. Our results propose novel oncogenic mechanisms of estrogen/antiestrogen use and HPV infection. We also suggest Eag1 as an early indicator of cell proliferation leading to malignancies and a therapeutic target at early stages of cellular hyperproliferation.

Epigenetic alterations mediate iPSC normalization of DNA-repair expression and TNR stability in Huntington's disease.

PubMed

Mollica, Peter A; Zamponi, Martina; Reid, John A; Sharma, Deepak K; White, Alyson E; Ogle, Roy C; Bruno, Robert D; Sachs, Patrick C

2018-06-13

Huntington's disease (HD) is a rare autosomal dominant neurodegenerative disorder caused by a cytosine-adenine-guanine (CAG) trinucleotide repeat (TNR) expansion within the HTT gene. The mechanisms underlying HD-associated cellular dysfunction during pluripotency and neurodevelopment, are poorly understood. Here we tested the hypothesis that hypomethylation during cellular reprogramming leads to up-regulation of DNA repair genes and stabilization of TNRs in HD cells. We sought to determine how the HD TNR region is affected by global epigenetic changes through cellular reprogramming and early neurodifferentiation. We find that early-stage HD-affected neural stem cells (NSCs) contain increased levels of global 5-hydroxymethylation (5-hmC) and normalized DNA repair gene expression. We confirm TNR stability is induced during pluripotency, and maintained in HD-NSCs. We also identify up-regulation of 5-hmC catalyzing ten-eleven translocation (TET1/2) proteins, and show their knockdown leads to a corresponding decrease in select DNA repair gene expression. We further confirm decreased expression of TET regulating miR-29 family members in HD-NSCs. Our findings demonstrate that mechanisms involved in pluripotency recover the selected DNA repair gene expression and stabilizes pathogenic TNRs in HD. © 2018. Published by The Company of Biologists Ltd.

Plasma-derived microparticles in polycythaemia vera.

PubMed

Ahadon, M; Abdul Aziz, S; Wong, C L; Leong, C F

2018-04-01

Microparticles are membrane bound vesicles, measuring less than 1.0 um, which are released during cellular activation or during apoptosis. Studies have shown that these circulating microparticles play a role in coagulation, cell signaling and cellular interactions. Increased levels of circulating microparticles have been observed in a number of conditions where there is vascular dysfunction, thrombosis and inflammation. The objective of this study was to determine the various plasma-derived microparticles in patients with polycythaemia vera (PV) in Universiti Kebangsaan Malaysia Medical Centre and to compare them with normal control. A total of 15 patients with PV and 15 healthy volunteers were included in this cross-sectional descriptive study. Plasma samples from both patients and healthy volunteers were prepared and further processed for isolation of microparticles. Flow cytometry analyses were then carried out in all samples to determine the cellular origin of the microparticles. Full blood count parameters for both groups were also collected. Data collected were analyzed using SPSS version 12.0. Patients with PV had a significantly higher percentage of platelet derived microparticles compared to healthy controls (P <0.05). The control group had a higher level of endothelial derived microparticles but the differences were not statistically significant (P > 0.05). The median percentage of positive events for platelet derived microparticles was higher in patients with PV compared to normal healthy controls.

Emerging roles of microRNAs as molecular switches in the integrated circuit of the cancer cell

PubMed Central

Sotiropoulou, Georgia; Pampalakis, Georgios; Lianidou, Evi; Mourelatos, Zissimos

2009-01-01

Transformation of normal cells into malignant tumors requires the acquisition of six hallmark traits, e.g., self-sufficiency in growth signals, insensitivity to antigrowth signals and self-renewal, evasion of apoptosis, limitless replication potential, angiogenesis, invasion, and metastasis, which are common to all cancers (Hanahan and Weinberg 2000). These new cellular traits evolve from defects in major regulatory microcircuits that are fundamental for normal homeostasis. The discovery of microRNAs (miRNAs) as a new class of small non-protein-coding RNAs that control gene expression post-transcriptionally by binding to various mRNA targets suggests that these tiny RNA molecules likely act as molecular switches in the extensive regulatory web that involves thousands of transcripts. Most importantly, accumulating evidence suggests that numerous microRNAs are aberrantly expressed in human cancers. In this review, we discuss the emergent roles of microRNAs as switches that function to turn on/off known cellular microcircuits. We outline recent compelling evidence that deregulated microRNA-mediated control of cellular microcircuits cooperates with other well-established regulatory mechanisms to confer the hallmark traits of the cancer cell. Furthermore, these exciting insights into aberrant microRNA control in cancer-associated circuits may be exploited for cancer therapies that will target deregulated miRNA switches. PMID:19561119

In vitro evaluation of low-intensity light radiation on murine melanoma (B16F10) cells.

PubMed

Peidaee, P; Almansour, N M; Pirogova, E

2016-03-01

Changes in the energy state of biomolecules induced by electromagnetic radiation lead to changes in biological functions of irradiated biomolecules. Using the RRM approach, it was computationally predicted that far-infrared light irradiation in the range of 3500-6000 nm affects biological activity of proto-oncogene proteins. This in vitro study evaluates quantitatively and qualitatively the effects of selected far-infrared exposures in the computationally determined wavelengths on mouse melanoma B16F10 cells and Chinese hamster ovarian (CHO) cells by MTT (thiazolyl blue tetrazolium bromide) cell proliferation assay and confocal laser-scanning microscopy (CLSM). This paper also presents the findings obtained from irradiating B16F10 and CHO cells by the selected wavelengths in visible and near-infrared range. The MTT results show that far-infrared wavelength irradiation induces detrimental effect on cellular viability of B16F10 cells, while that of normal CHO cells is not affected considerably. Moreover, CLSM images demonstrate visible cellular detachment of cancer cells. The observed effects support the hypothesis that far-infrared light irradiation within the computationally determined wavelength range induces biological effect on cancer cells. From irradiation of selected visible and near-infrared wavelengths, no visible changes were detected in cellular viability of either normal or cancer cells.

Role of Metalloproteases in Vaccinia Virus Epitope Processing for Transporter Associated with Antigen Processing (TAP)-independent Human Leukocyte Antigen (HLA)-B7 Class I Antigen Presentation*

PubMed Central

Lorente, Elena; García, Ruth; Mir, Carmen; Barriga, Alejandro; Lemonnier, François A.; Ramos, Manuel; López, Daniel

2012-01-01

The transporter associated with antigen processing (TAP) translocates the viral proteolytic peptides generated by the proteasome and other proteases in the cytosol to the endoplasmic reticulum lumen. There, they complex with nascent human leukocyte antigen (HLA) class I molecules, which are subsequently recognized by the CD8+ lymphocyte cellular response. However, individuals with nonfunctional TAP complexes or tumor or infected cells with blocked TAP molecules are able to present HLA class I ligands generated by TAP-independent processing pathways. Herein, using a TAP-independent polyclonal vaccinia virus-polyspecific CD8+ T cell line, two conserved vaccinia-derived TAP-independent HLA-B*0702 epitopes were identified. The presentation of these epitopes in normal cells occurs via complex antigen-processing pathways involving the proteasome and/or different subsets of metalloproteinases (amino-, carboxy-, and endoproteases), which were blocked in infected cells with specific chemical inhibitors. These data support the hypothesis that the abundant cellular proteolytic systems contribute to the supply of peptides recognized by the antiviral cellular immune response, thereby facilitating immunosurveillance. These data may explain why TAP-deficient individuals live normal life spans without any increased susceptibility to viral infections. PMID:22298786

Binding affinity of amyloid oligomers to cellular membranes is a generic indicator of cellular dysfunction in protein misfolding diseases

PubMed Central

Evangelisti, Elisa; Cascella, Roberta; Becatti, Matteo; Marrazza, Giovanna; Dobson, Christopher M.; Chiti, Fabrizio; Stefani, Massimo; Cecchi, Cristina

2016-01-01

The conversion of peptides or proteins from their soluble native states into intractable amyloid deposits is associated with a wide range of human disorders. Misfolded protein oligomers formed during the process of aggregation have been identified as the primary pathogenic agents in many such conditions. Here, we show the existence of a quantitative relationship between the degree of binding to neuronal cells of different types of oligomers formed from a model protein, HypF-N, and the GM1 content of the plasma membranes. In addition, remarkably similar behavior is observed for oligomers of the Aβ42 peptide associated with Alzheimer’s disease. Further analysis has revealed the existence of a linear correlation between the level of the influx of Ca2+ across neuronal membranes that triggers cellular damage, and the fraction of oligomeric species bound to the membrane. Our findings indicate that the susceptibility of neuronal cells to different types of misfolded oligomeric assemblies is directly related to the extent of binding of such oligomers to the cellular membrane. PMID:27619987

HLH-30/TFEB-mediated autophagy functions in a cell-autonomous manner for epithelium intrinsic cellular defense against bacterial pore-forming toxin in C. elegans.

PubMed

Chen, Huan-Da; Kao, Cheng-Yuan; Liu, Bang-Yu; Huang, Shin-Whei; Kuo, Cheng-Ju; Ruan, Jhen-Wei; Lin, Yen-Hung; Huang, Cheng-Rung; Chen, Yu-Hung; Wang, Horng-Dar; Aroian, Raffi V; Chen, Chang-Shi

2017-02-01

Autophagy is an evolutionarily conserved intracellular system that maintains cellular homeostasis by degrading and recycling damaged cellular components. The transcription factor HLH-30/TFEB-mediated autophagy has been reported to regulate tolerance to bacterial infection, but less is known about the bona fide bacterial effector that activates HLH-30 and autophagy. Here, we reveal that bacterial membrane pore-forming toxin (PFT) induces autophagy in an HLH-30-dependent manner in Caenorhabditis elegans. Moreover, autophagy controls the susceptibility of animals to PFT toxicity through xenophagic degradation of PFT and repair of membrane-pore cell-autonomously in the PFT-targeted intestinal cells in C. elegans. These results demonstrate that autophagic pathways and autophagy are induced partly at the transcriptional level through HLH-30 activation and are required to protect metazoan upon PFT intoxication. Together, our data show a new and powerful connection between HLH-30-mediated autophagy and epithelium intrinsic cellular defense against the single most common mode of bacterial attack in vivo.

Cellular defense against singlet oxygen-induced oxidative damage by cytosolic NADP+-dependent isocitrate dehydrogenase.

PubMed

Kim, Sun Yee; Park, Jeen-Woo

2003-03-01

Singlet oxygen (1O2) is a highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules. Recently, we have shown that NADP+-dependent isocitrate dehydrogenase is involved in the supply of NADPH needed for GSH production against cellular oxidative damage. In this study, we investigated the role of cytosolic form of NADP+-dependent isocitrate dehydrogenase (IDPc) against singlet oxygen-induced cytotoxicity by comparing the relative degree of cellular responses in three different NIH3T3 cells with stable transfection with the cDNA for mouse IDPc in sense and antisense orientations, where IDPc activities were 2.3-fold higher and 39% lower, respectively, than that in the parental cells carrying the vector alone. Upon exposure to singlet oxygen generated from photoactivated dye, the cells with low levels of IDPc became more sensitive to cell killing. Lipid peroxidation, protein oxidation, oxidative DNA damage and intracellular peroxide generation were higher in the cell-line expressing the lower level of IDPc. However, the cells with the highly over-expressed IDPc exhibited enhanced resistance against singlet oxygen, compared to the control cells. The data indicate that IDPc plays an important role in cellular defense against singlet oxygen-induced oxidative injury.

Cellular automata and integrodifferential equation models for cell renewal in mosaic tissues

PubMed Central

Bloomfield, J. M.; Sherratt, J. A.; Painter, K. J.; Landini, G.

2010-01-01

Mosaic tissues are composed of two or more genetically distinct cell types. They occur naturally, and are also a useful experimental method for exploring tissue growth and maintenance. By marking the different cell types, one can study the patterns formed by proliferation, renewal and migration. Here, we present mathematical modelling suggesting that small changes in the type of interaction that cells have with their local cellular environment can lead to very different outcomes for the composition of mosaics. In cell renewal, proliferation of each cell type may depend linearly or nonlinearly on the local proportion of cells of that type, and these two possibilities produce very different patterns. We study two variations of a cellular automaton model based on simple rules for renewal. We then propose an integrodifferential equation model, and again consider two different forms of cellular interaction. The results of the continuous and cellular automata models are qualitatively the same, and we observe that changes in local environment interaction affect the dynamics for both. Furthermore, we demonstrate that the models reproduce some of the patterns seen in actual mosaic tissues. In particular, our results suggest that the differing patterns seen in organ parenchymas may be driven purely by the process of cell replacement under different interaction scenarios. PMID:20375040

Cortactin Branches Out: Roles in Regulating Protrusive Actin Dynamics

PubMed Central

Ammer, Amanda Gatesman; Weed, Scott A.

2008-01-01

Since its discovery in the early 1990’s, cortactin has emerged as a key signaling protein in many cellular processes, including cell adhesion, migration, endocytosis, and tumor invasion. While the list of cellular functions influenced by cortactin grows, the ability of cortactin to interact with and alter the cortical actin network is central to its role in regulating these processes. Recently, several advances have been made in our understanding of the interaction between actin and cortactin, providing insight into how these two proteins work together to provide a framework for normal and altered cellular function. This review examines how regulation of cortactin through post-translational modifications and interactions with multiple binding partners elicits changes in cortical actin cytoskeletal organization, impacting the regulation and formation of actin-rich motility structures. PMID:18615630

In search of cellular control: signal transduction in context

NASA Technical Reports Server (NTRS)

Ingber, D.

1998-01-01

The field of molecular cell biology has experienced enormous advances over the last century by reducing the complexity of living cells into simpler molecular components and binding interactions that are amenable to rigorous biochemical analysis. However, as our tools become more powerful, there is a tendency to define mechanisms by what we can measure. The field is currently dominated by efforts to identify the key molecules and sequences that mediate the function of critical receptors, signal transducers, and molecular switches. Unfortunately, these conventional experimental approaches ignore the importance of supramolecular control mechanisms that play a critical role in cellular regulation. Thus, the significance of individual molecular constituents cannot be fully understood when studied in isolation because their function may vary depending on their context within the structural complexity of the living cell. These higher-order regulatory mechanisms are based on the cell's use of a form of solid-state biochemistry in which molecular components that mediate biochemical processing and signal transduction are immobilized on insoluble cytoskeletal scaffolds in the cytoplasm and nucleus. Key to the understanding of this form of cellular regulation is the realization that chemistry is structure and hence, recognition of the the importance of architecture and mechanics for signal integration and biochemical control. Recent work that has unified chemical and mechanical signaling pathways provides a glimpse of how this form of higher-order cellular control may function and where paths may lie in the future.