scholarly journals CLEAR AS MUD: THE TYPE I/TYPE II MODEL FOR DEATH RECEPTOR-INDUCED APOPTOSIS

2006 ◽  
Vol 43 (2) ◽  
Author(s):  
David Michael Conrad
Keyword(s):  
Death Receptor ◽  
Mitochondrial Pathway ◽  
Type I ◽  
Biological Processes ◽  
Type Ii ◽  
Type Ii Cell ◽  
Mort Cellulaire ◽  
Induced Apoptosis ◽  
First Time ◽  
The Relationship

Apoptosis is a highly organized form of cell death that plays an important regulatory role in many biological processes. The relationship between the two classical signalling pathways of apoptosis, the “death receptor” and “mitochondrial” pathways, was only vaguely appreciated until 1998, when death receptor pathway-mediated activation of the mitochondrial pathway was clearly demonstrated for the first time. The “type I/type II” model of death receptor-mediated apoptosis was proposed and subsequently adopted for use in categorizing cells according to the involvement of the mitochondrion duringdeath receptor-induced apoptosis. Since that time, however, different interpretations of the type I/type II cell definition have appeared in the literature and, consequently, the meaning of type I and type II cells has become less clear.L’apoptose est une forme de mort cellulaire très structurée qui joue un rôle important de régulation dans un grand nombre de processus biologiques. La relation entre les deux voies de signalisation traditionnelles de l’apoptose, la voie des « récepteurs de mort » et la voie mitochondriale, n’était connue que vaguement avant 1998, l'année où l’activation de la voie mitochondriale par l’intermédiaire de la voie des récepteurs de mort a été clairement démontrée pour la première fois. Le modèle « type I / type II » d’apoptose par l’intermédiaire des récepteurs de mort a été proposé puis adopté auxfins de catégorisation des cellules en fonction de la participation des mitochondries à cette apoptose. Depuis, différentes interprétations ont toutefois été formulées dans des ouvrages scientifiques quant à la définition des cellules de type I et de type II et, par conséquent, la signification de « cellules de type I » et de « cellules de type II » est devenue moins évidente.

scholarly journals STL-based Analysis of TRAIL-induced Apoptosis Challenges the Notion of Type I/Type II Cell Line Classification

2013 ◽  
Vol 9 (5) ◽  
pp. e1003056 ◽  
Author(s):  
Szymon Stoma ◽  
Alexandre Donzé ◽  
François Bertaux ◽  
Oded Maler ◽  
Gregory Batt
Keyword(s):  
Cell Line ◽  
Type I ◽  
Type Ii ◽  
Type Ii Cell ◽  
Induced Apoptosis ◽  
Line Classification

scholarly journals PTEN Loss Promotes Mitochondrially Dependent Type II Fas-Induced Apoptosis via PEA-15

2008 ◽  
Vol 29 (5) ◽  
pp. 1222-1234 ◽  
Author(s):  
James W. Peacock ◽  
Jodie Palmer ◽  
Dieter Fink ◽  
Stephen Ip ◽  
Eric M. Pietras ◽  
...  
Keyword(s):  
Death Receptor ◽  
Type I ◽  
Type Ii ◽  
Loss Of Function ◽  
Apoptotic Pathway ◽  
Pten Loss ◽  
Activated T Lymphocytes ◽  
Apoptosis Pathways ◽  
Induced Apoptosis ◽  
Dependent Type

ABSTRACT Two distinct biochemical signals are delivered by the CD95/Fas death receptor. The molecular basis for the differential mitochondrially independent (type I) and mitochondrially dependent (type II) Fas apoptosis pathways is unknown. By analyzing 24 Fas-sensitive tumor lines, we now demonstrate that expression/activity of the PTEN tumor suppressor strongly correlates with the distinct Fas signals. PTEN loss-of-function and gain-of-function studies demonstrate the ability to interconvert between type I and type II Fas pathways. Importantly, from analyses of Bcl-2 transgenic Pten +/− mice, Pten haploinsufficiency converts Fas-induced apoptosis from a Bcl-2-independent to a Bcl-2-sensitive response in primary thymocytes and activated T lymphocytes. We further show that PTEN influences Fas signaling, at least in part, by regulating PEA-15 phosphorylation and activity that, in turn, regulate the ability of Bcl-2 to suppress Fas-induced apoptosis. Thus, PTEN is a key molecular rheostat that determines whether a cell dies by a mitochondrially independent type I versus a mitochondrially dependent type II apoptotic pathway upon Fas stimulation.

scholarly journals Electron Transfer Initiated Reactions Photoinduced by Pterins

Pteridines ◽  
2011 ◽  
Vol 22 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Carolina Lorente ◽  
Gabriela Petroselli ◽  
M. Laura Dántola ◽  
Esther Oliveros ◽  
Andrés H. Thomas
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Redox Reactions ◽  
Type I ◽  
Biological Processes ◽  
Type Ii ◽  
Triplet Excited State ◽  
Oxygen Production ◽  
Production Type ◽  
Transfer Mechanisms

Abstract Interest in the photochemistry and photophysics of pterins has increased since the participation of this family of compounds in different photobiological processes has been suggested or demonstrated in recent decades. Pterins participate in relevant biological processes, such as metabolic redox reactions, and can photoinduce the oxidation of biomolecules through both electron transfer mechanisms (Type I) and singlet oxygen production (Type II). This article describes recent findings on electron transfer-initiated reactions photoinduced by the triplet excited state of pterins and connects them in the context of photosensitized processes of biological relevance.

Sulfation of extracellular matrices modifies responses of alveolar type II cells to fibroblast growth factors

1996 ◽  
Vol 271 (5) ◽  
pp. L688-L697 ◽  
Author(s):  
P. L. Sannes ◽  
J. Khosla ◽  
P. W. Cheng
Keyword(s):  
Growth Factors ◽  
Biological Significance ◽  
Alveolar Type ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Fibroblast Growth ◽  
Alveolar Type Ii Cells ◽  
Proliferation And Differentiation ◽  
Type Ii Cell

The pulmonary alveolar basement membrane (BM) associated with alveolar type II cells has been shown to be significantly less sulfated than that of type I cells. To examine the biological significance of this observation, we measured the incorporation of 5-bromodeoxyuridine (BrdU) as an indicator of DNA synthesis in isolated rat type II cells cultured for 72-120 h on substrata that were naturally sulfated, not sulfated, or chemically desulfated in serum-free, hormonally defined media, with and without selected growth factors. The percentage of cells incorporating BrdU was significantly elevated by desulfated chondroitin sulfate in the presence of fibroblast growth factor-2 (FGF-2 or basic FGF) and depressed by heparin in the presence of either FGF-1 or acidic FGF or FGF-2. This depressive effect was lost by removing sulfate from the heparin. Some responses were dependent on the period of time in culture and concentration and molecular weight of the substrata. These observations support the notion that sulfation per se of certain components of BM is a key determinant of type II cell responses to select growth factors that may define patterns of proliferation and differentiation.

scholarly journals A Locomotor Disorder Clinically Similar to Spastic Paresis in an Adult Friesian Bull

1980 ◽  
Vol 17 (3) ◽  
pp. 305-315 ◽  
Author(s):  
R. Bradley ◽  
W.V.S. Wueratne
Keyword(s):  
Skeletal Muscles ◽  
Hind Limb ◽  
Type I ◽  
Type Ii ◽  
Hind Limbs ◽  
Type Ii Cell ◽  
Spastic Paresis ◽  
Flexor Digitorum ◽  
I Cells ◽  
Severe Type

A 5-year-old Friesian stud bull developed a progressive locomotor disorder on return to stud after a period of rest. He had defects in conformation exacerbated by poor condition. The hind limbs were excessively straight. When he stood or moved, the Achilles tendons and their associated muscles were rigid. The disorder clinically resembled spastic paresis of calves. Necropsy showed a degenerative arthropathy in all hind limb joints below the hip. Lesions were also in tendons and skeletal muscles. The M. flexor digitorum superficialis had severe type II cell atrophy with many ring. lobulated and moth-eaten type I cells.

scholarly journals Type I interferon promotes alveolar epithelial type II cell survival during pulmonary Streptococcus pneumoniae infection and sterile lung injury in mice

2016 ◽  
Vol 46 (9) ◽  
pp. 2175-2186 ◽  
Author(s):  
Barbara B. Maier ◽  
Anastasiya Hladik ◽  
Karin Lakovits ◽  
Ana Korosec ◽  
Rui Martins ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Lung Injury ◽  
Cell Survival ◽  
Type I Interferon ◽  
Type I ◽  
Type Ii ◽  
Alveolar Epithelial ◽  
Type Ii Cell

Revisiting the Relationships between Turkish Prospective Teachers' Thinking Styles and Behaviors Fostering Creativity

2017 ◽  
pp. 136-157
Author(s):  
Ayhan Dikici
Keyword(s):  
Factor Analysis ◽  
Trend Analysis ◽  
Prospective Teachers ◽  
Zero Order ◽  
Thinking Styles ◽  
Type I ◽  
Type Ii ◽  
Quadratic Trend ◽  
Fostering Creativity ◽  
The Relationship

This chapter aims to reexamine the relationship between Turkish prospective teachers' thinking styles and creativity fostering behaviors. In the study, 182 Turkish prospective teachers were participated. The Thinking Styles Inventory (TSI) and Creativity Fostering Teacher Index Scale (CFTIS) were administered to participants. An exploratory factor analysis, zero order and partial correlation, linear and quadratic trend analysis were conducted on the data. The results indicated that Type I thinking styles are a more powerful predictor for creativity fostering behaviors than Type II thinking styles. Prospective teachers' implicit opinions about creativity negatively predicted to CFTIS. Relationship between Type I and Type II thinking styles, and creativity fostering behaviors were positively significant in the results of quadratic trend analysis; however, the relationship between implicit opinions about creativity and creativity fostering behaviors were negatively significant in the analysis. The results obtained from the study were discussed based on previous studies.

Cell cycle kinetics in the alveolar epithelium

1997 ◽  
Vol 272 (6) ◽  
pp. L1031-L1045 ◽  
Author(s):  
B. D. Uhal
Keyword(s):  
Epithelial Cell ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelium ◽  
Cell Loss ◽  
Type Ii ◽  
Alveolar Epithelial ◽  
Pathological Conditions ◽  
Type Ii Cell ◽  
The Relationship

The type II alveolar epithelial cell has important metabolic and biosynthetic functions but also serves as the stem cell of the alveolar epithelium. Much of the evidence underlying this premise was obtained before 1980 and provided the basis for a working model that has not been reconsidered for more than fifteen years. With the exceptions to be discussed below, little evidence has accumulated in the interim to suggest that the model requires significant alteration. Important questions remain unanswered, however, and some components of the model need to be supplemented, particularly in light of recent investigations that have provided insights not possible in earlier work. In particular, in vitro studies have suggested that the relationship between the parent type II cell and its progeny may not be as straightforward as originally thought. In addition, the rate of epithelial cell loss was recognized long ago to be an important factor in the regulation of this system, but its kinetics and mechanisms have received little attention. These and other unresolved issues are critical to our understanding of the homeostasis of the alveolar epithelium under normal and pathological conditions.

Transport Properties of Type II Sodium-Silicon Clathrates

2005 ◽  
Vol 886 ◽  
Author(s):  
Matt Beekman ◽  
Jan Grkyo ◽  
George S. Nolas
Keyword(s):  
Thermal Conductivity ◽  
Sodium Content ◽  
Type I ◽  
Type Ii ◽  
Conductivity Measurements ◽  
Scanning Calorimetry ◽  
Resistivity Measurements ◽  
Silicon Clathrates ◽  
Covalently Bonded ◽  
First Time

ABSTRACTWe have synthesized the type II silicon clathrates Na1Si136 and Na8Si136, and report on the electrical and thermal transport in these materials. The crystal structure consists of a covalently bonded silicon framework in which sodium guest atoms are encapsulated inside the silicon host framework. Differential scanning calorimetry measurements show the compounds decompose above 600°C to diamond-structure silicon. Temperature dependant electrical resistivity measurements show the specimens to have an insulating character, with magnitudes that decrease with increasing sodium content. For the first time, thermal conductivity measurements on type II sodium-silicon clathrates are presented. The thermal conductivity is very low for both specimens, and for Na8Si136 exhibits a clear dip in the range from 50 to 70 K. These data suggest that the “rattling” behavior observed in type I clathrates may also be present in type II clathrates.

Alveolar type II cell growth on a pulmonary endothelial extracellular matrix

1996 ◽  
Vol 270 (6) ◽  
pp. L1017-L1022 ◽  
Author(s):  
I. Y. Adamson ◽  
L. Young
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Cell Growth ◽  
Alveolar Type ◽  
Thymidine Uptake ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lamellar Bodies ◽  
Type Ii Cell

Most of the alveolar epithelium overlies a fused basement membrane produced by epithelial and endothelial cells. To determine how this type of matrix influences type II cell growth and function, we studied the effects of culturing isolated rat alveolar type II cells on an extracellular matrix (ECM) freshly produced by pulmonary vascular endothelial cells grown 5 days in culture. Type II cells from the same rats were cultured on plastic or Matrigel for comparison. A large increase in mitotic activity was seen in type II cells grown on the endothelial ECM at 2 days only; thereafter cells spread rapidly to confluence and lost their lamellar bodies. Cells grown on Matrigel remained cuboidal with lamellar bodies but grew more slowly, as judged by [3H]thymidine uptake and cell numbers. Incorporation of labeled choline into disaturated phosphatidylcholine (DSPC) was used as a marker of surfactant synthesis. After the rapid, brief burst of proliferation, type II cells on endothelial ECM showed a sudden decline in DSPC-DNA by day 4 compared with cells grown on matrigel. Binding of the lectin Bauhinia purpurea (BPA) indicated that after a phase of division, cells on endothelial ECM developed as type I epithelium by 4 days of culture, when > 70% of cells stained positively for BPA binding, whereas few cuboidal cells on Matrigel were stained. The results indicate that type II cells respond briefly to growth factors in pulmonary endothelial ECM; then this type of matrix promotes cell spreading with loss of type II function as cells subsequently resemble type I epithelium.

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