Reiterative use of signalling pathways controls multiple cellular events during Drosophila posterior spiracle organogenesis

AbstractTWEAK (tumor necrosis factor-like weak inducer of apoptosis) is a member of the TNF superfamily that controls a multitude of cellular events including proliferation, migration, differentiation, apoptosis, angiogenesis, and inflammation. TWEAK control of these events is via an expanding list of intracellular signalling pathways which include NF-κB, ERK/MAPK, Notch, EGFR and AP-1. Two receptors have been identified for TWEAK – Fn14, which targets the membrane bound form of TWEAK, and CD163, which scavenges the soluble form of TWEAK. TWEAK appears to elicit specific events based on the receptor to which it binds, tissue type in which it is expressed, specific extrinsic conditions, and the presence of other cytokines. TWEAK signalling is protective in healthy tissues, but in chronic inflammatory states become detrimental to the tissue. Consistent data show a role for the TWEAK/FN14/CD163 axis in metabolic disease, chronic autoimmune diseases, and acute ischaemic stroke. Low circulating concentrations of soluble TWEAK are predictive of poor cardiovascular outcomes in those with and without diabetes. This review details the current understanding of the TWEAK/Fn14/CD163 axis as one of the chief regulators of immune signalling and its cell-specific role in metabolic disease development and progression.

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Plant defence responses: what have we learnt from Arabidopsis?

Functional Plant Biology ◽

10.1071/fp04135 ◽

2005 ◽

Vol 32 (1) ◽

pp. 1 ◽

Cited By ~ 90

Author(s):

Louise F. Thatcher ◽

Jonathan P. Anderson ◽

Karam B. Singh

Keyword(s):

Plant Defence ◽

Signalling Pathways ◽

Induced Responses ◽

Form Complex ◽

Cellular Events ◽

Model Plant Arabidopsis Thaliana ◽

Defence Signalling ◽

Defence Responses ◽

Plant Defence Responses ◽

Plant Arabidopsis Thaliana

To overcome the attack of invading pathogens, a plant’s defence system relies on preformed and induced responses. The induced responses are activated following detection of a pathogen, with the subsequent transmission of signals and orchestrated cellular events aimed at eliminating the pathogen and preventing its spread. Numerous studies are proving that the activated signalling pathways are not simply linear, but rather, form complex networks where considerable cross talk takes place. This review covers the recent application of powerful genetic and genomic approaches to identify key defence signalling pathways in the model plant Arabidopsis thaliana (L.) Heynh. The identification of key regulatory components of these pathways may offer new approaches to increase the defence capabilities of crop plants.

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Uses of the in vitro endothelial–fibroblast organotypic co-culture assay in angiogenesis research

Biochemical Society Transactions ◽

10.1042/bst20110738 ◽

2011 ◽

Vol 39 (6) ◽

pp. 1597-1600 ◽

Cited By ~ 31

Author(s):

Clare Hetheridge ◽

Georgia Mavria ◽

Harry Mellor

Keyword(s):

Quantitative Data ◽

Small Interfering Rna ◽

Cell Types ◽

Signalling Pathways ◽

Cellular Events ◽

Complex Process ◽

Key Events ◽

Interfering Rna ◽

Multiple Interactions

Angiogenesis is a complex process that involves multiple cellular events. In addition to receiving inputs from a range of stimulatory and inhibitory factors, endothelial cells undergoing angiogenesis make multiple interactions with the extracellular matrix and with other cell types in the stroma. Recreating angiogenesis in vitro is probably an impossible goal; however, a number of assays have been developed that recapitulate many of the key events of the process. These assays are indispensible tools for investigating the signalling pathways that control the formation of new blood vessels. In the present paper, we review the organotypic co-culture assay of angiogenesis – until recently, a comparatively underemployed assay, but one with a number of powerful advantages for angiogenesis research. We give a set of optimized protocols for its use, including protocols for siRNA (small interfering RNA)-based screens, and we discuss appropriate methods for obtaining quantitative data from the assay.

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Caspases and apoptosis

Essays in Biochemistry ◽

10.1042/bse0380009 ◽

2002 ◽

Vol 38 ◽

pp. 9-19 ◽

Cited By ~ 121

Author(s):

Guy S Salvesen

Keyword(s):

Cysteine Proteases ◽

Signalling Pathways ◽

Term Survival ◽

Mature Adult ◽

Intracellular Signalling Pathways ◽

Adult Cell ◽

Caspase Family ◽

Cell Fragments ◽

Pro Inflammatory Cytokines

The ability of metazoan cells to undergo programmed cell death is vital to both the precise development and long-term survival of the mature adult. Cell deaths that result from engagement of this programme end in apoptosis, the ordered dismantling of the cell that results in its 'silent' demise, in which packaged cell fragments are removed by phagocytosis. This co-ordinated demise is mediated by members of a family of cysteine proteases known as caspases, whose activation follows characteristic apoptotic stimuli, and whose substrates include many proteins, the limited cleavage of which causes the characteristic morphology of apoptosis. In vertebrates, a subset of caspases has evolved to participate in the activation of pro-inflammatory cytokines, and thus members of the caspase family participate in one of two very distinct intracellular signalling pathways.

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Nutrient-regulated gene expression in eukaryotes

Biochemical Society Symposium ◽

10.1042/bss0730085 ◽

2006 ◽

Vol 73 ◽

pp. 85-96 ◽

Cited By ~ 8

Author(s):

Richard J. Reece ◽

Laila Beynon ◽

Stacey Holden ◽

Amanda D. Hughes ◽

Karine Rébora ◽

...

Keyword(s):

Gene Expression ◽

Rna Polymerase ◽

Rna Polymerase Ii ◽

Transcriptional Control ◽

Direct Interaction ◽

Signalling Pathways ◽

A Cell ◽

One Step ◽

Higher Eukaryotes ◽

Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

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