Tumor Necrosis Factor Alpha == |+|
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|−|==Introduction == |+|
|−|Tumor Necrosis Factor Alpha (TNF-α) belongs to the Tumor Necrosis Factor superfamily (Member 2). It is. It was first discovered by Carswell et al. in 1975 in mouse serum after injection with Mycobacterium bovis strain bacillus Calmette-Guerin (BCG) and endotoxin . TNF-α is now often recognized under various other titles including simply Tumor Necrosis Factor (TNF); TNFA, Cachectin, Monocyte-derived TNF, Macrophage-derived TNF  and is now known to be one of the most significant members of its class. |+|
|−|This serum glycoprotein is a potent cytokine responsible for initiating a broad spectrum of processes that can have effects at both the cellular and systemic levels. Activation of these processes occurs upon binding of the protein to its various cell-surface receptors. TNF-α is predominantly produced and secreted (in soluble form) by activated monocytes/macrophages during the inflammatory response (acute and chronic) however, TNF-α is also produced by other mononuclear leukocytes . Since TNF-α is a potent inflammatory glycoprotein, its production is typically stimulated by both exogenous and endogenous factors including bacteria, viruses, and other cytokines . Bacteria cell walls contain lipopolysaccharides which are a particularly potent stimulus for TNF-A synthesis . |+|
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|−|With a diverse range of regulative effects on biologic processes, TNF-α is involved in lipid metabolism, coagulation, cell proliferation, differentiation, apoptosis, necrosis, insulin resistance, and endothelial function, amongst various other processes . Previous studies also reveal that TNF-α has been implicated in the induction of a variety of pathologic conditions including autoimmune diseases, insulin resistance, and cancer  where much of these studies involved experimentation using knockout mice models to demonstrate and better understand the role of TNF-α in the human body. | |
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|−|== Structure and Gene == |+|
|−|TNF-α was initially identified in its soluble, cleaved form of approximately 17-kD, however with further research it was later identified in its insoluble, non-cleaved form of approximately 26-kD, existing as a trans-membrane protein ( Perez, et al., 1990) . TNF-α is currently described as a homotrimeric protein which is encoded within the Major Histocompatibility Complex (MHC) and has been mapped to chromosome 6p21. 3 [REFERENCE]. The following is a link to an interactive murine model of TNF-α. |+|
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|−|== Receptors and Signalling == |+|
is a variety of Tumor Necrosis Factor Receptors that exist as trans- mebrane proteins. Each receptor that belongs to the TNF family consists of three primary parts: an extracellular ligand- binding domain, a trans- membrane part and an intracellular death domain, however the defining trait of all Tumor Necrosis Factor Receptors is the extra cellular domain comprised of two to six repeats of cysteine rich motifs . |+|
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|−|== Function == |+|
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|−|== Abnormalities == |+|
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|−|== References == |+|
Outline something new that you learnt from this lecture.
I learnt about Nuclear Bodies (Cajal and PML) that, to my recollection, I hadn't heard of previously. I also learnt some things about chromosomes that were fairly new. Also, I liked the picture of Nuclear Pores. I had heard about them for a good while but could never really visualise what they might look like - kinda cool.
What did you find difficult to understand?
Everything was pretty understandable because you have a nice voice that's very easy to listen to; like the voices on TV. Perhaps when we study the Cytoskeleton and ECM later on I can build on my knowledge of the structural role of intermediate filaments.
What are the main energy processes in the cell?
Mitochondria is an organelle in cells. The main function of mitochondria is to produce energy (ATP) for the cell using raw materials such as oxygen and fatty acids. In plant cells chloroplasts are highly involved in energy production.
There are different types of Cell Adhesion Molecules present within the Nervous System that each serve a different role:
N-CAMs are Neuronal Cell Adhesion Molecules.
Ng-CAMs are Neuron-glia Cell Adhesion Molecules involved in promoting the regeneration of a nerve subsequent to damage. In addition to this Ng-CAMs are associated with adhesion across the axon.
L-CAMs are Liver Cell Adhesion Molecules that are involved in maintaining the architectural integrity of the liver with cell-cell adhesion.
I-CAMs are Intercellular Adhesion Molecules that are closely associated with the inflammatory response. They often mediate adhesive interactions important for antigen-specific immune responses and are are involved in WBC recirculation when they act to block cell ahesion.
What is the layer of the skin that contains a high concentration of intermediate filaments that form desmosomes? (Hint: between the Statum Granulosum and Stratum Basale layer of the skin). This layer is the Stratum Spinosum.