Biomaterial Database

[Possible cytotoxic mechanisms of TNF in vitro]. 1990

S Iwamoto, and K Takeda

First Department of Biochemistry, School of Medicine, Showa University, Japan.

TNF is a protein originally isolated by its ability to induce hemorrhagic necrosis of some tumors in vivo, and cytotoxic effects against certain tumor cells, but not against normal cells in vitro. Though mechanisms of the cytotoxicity and selectivity of TNF action in vitro are not clear, there is much evidence that free radicals such as superoxide and hydroxyl radicals, mediated by TNF, are correlated with TNF cytotoxicity. Recently, manganous superoxide dismutase (MnSOD) in mitochondria has been demonstrated to be a rescue protein against TNF cytotoxicity and to be induced when the cells are exposed to TNF in the resistant cells. Two steroid hormones, glucocorticoid and 1,25-dihydroxyvitamin D3, block the cytotoxicity of TNF. Glucocorticoid may reduce TNF cytotoxicity by inhibiting phospholipase A2 and 1,25-dihydroxyvitamin D3 by inducing MnSOD in combination with TNF.

UI	MeSH Term	Description	Entries
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D009369	Neoplasms	New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.	Benign Neoplasm,Cancer,Malignant Neoplasm,Tumor,Tumors,Benign Neoplasms,Malignancy,Malignant Neoplasms,Neoplasia,Neoplasm,Neoplasms, Benign,Cancers,Malignancies,Neoplasias,Neoplasm, Benign,Neoplasm, Malignant,Neoplasms, Malignant
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D002762	Cholecalciferol	Derivative of 7-dehydroxycholesterol formed by ULTRAVIOLET RAYS breaking of the C9-C10 bond. It differs from ERGOCALCIFEROL in having a single bond between C22 and C23 and lacking a methyl group at C24.	Vitamin D 3,(3 beta,5Z,7E)-9,10-Secocholesta-5,7,10(19)-trien-3-ol,Calciol,Cholecalciferols,Vitamin D3
D005609	Free Radicals	Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.	Free Radical
D005938	Glucocorticoids	A group of CORTICOSTEROIDS that affect carbohydrate metabolism (GLUCONEOGENESIS, liver glycogen deposition, elevation of BLOOD SUGAR), inhibit ADRENOCORTICOTROPIC HORMONE secretion, and possess pronounced anti-inflammatory activity. They also play a role in fat and protein metabolism, maintenance of arterial blood pressure, alteration of the connective tissue response to injury, reduction in the number of circulating lymphocytes, and functioning of the central nervous system.	Glucocorticoid,Glucocorticoid Effect,Glucorticoid Effects,Effect, Glucocorticoid,Effects, Glucorticoid
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001095	Arachidonic Acids		Eicosatetraenoic Acids,Acids, Arachidonic,Acids, Eicosatetraenoic
D013481	Superoxides	Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to METHEMOGLOBIN. In living organisms, SUPEROXIDE DISMUTASE protects the cell from the deleterious effects of superoxides.	Superoxide Radical,Superoxide,Superoxide Anion
D013482	Superoxide Dismutase	An oxidoreductase that catalyzes the reaction between SUPEROXIDES and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide.	Hemocuprein,Ag-Zn Superoxide Dismutase,Cobalt Superoxide Dismutase,Cu-Superoxide Dismutase,Erythrocuprein,Fe-Superoxide Dismutase,Fe-Zn Superoxide Dismutase,Iron Superoxide Dismutase,Manganese Superoxide Dismutase,Mn-SOD,Mn-Superoxide Dismutase,Ag Zn Superoxide Dismutase,Cu Superoxide Dismutase,Dismutase, Ag-Zn Superoxide,Dismutase, Cobalt Superoxide,Dismutase, Cu-Superoxide,Dismutase, Fe-Superoxide,Dismutase, Fe-Zn Superoxide,Dismutase, Iron Superoxide,Dismutase, Manganese Superoxide,Dismutase, Mn-Superoxide,Dismutase, Superoxide,Fe Superoxide Dismutase,Fe Zn Superoxide Dismutase,Mn SOD,Mn Superoxide Dismutase,Superoxide Dismutase, Ag-Zn,Superoxide Dismutase, Cobalt,Superoxide Dismutase, Fe-Zn,Superoxide Dismutase, Iron,Superoxide Dismutase, Manganese