Biomaterial Database

Mechanisms of lysosomal enzyme secretion by human U-937 monocytes. 1983

P Leoni, and R T Dean

Lysosomal enzyme secretion was studied in U-937, a mononuclear phagocyte cell line. The secretion of the marker enzyme, beta-N-acetyl-D-glucosaminidase, was low when the cells were challenged with phagocytosable stimuli (asbestos, zymosan, opsonised zymosan). Ammonium chloride and cytochalasin B induced secretion over 24 h of incubation. Phorbol myristate acetate and F-methyl-leucyl-phenylalanine, did not have any effect on secretion. It is suggested that U-937 cells may provide a useful model for the study of mononuclear phagocyte secretory pathways.

UI	MeSH Term	Description	Entries
D008222	Lymphokines	Soluble protein factors generated by activated lymphocytes that affect other cells, primarily those involved in cellular immunity.	Lymphocyte Mediators,Mediators, Lymphocyte
D008247	Lysosomes	A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured or undergoes MEMBRANE FUSION. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed).	Autolysosome,Autolysosomes,Lysosome
D009000	Monocytes	Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.	Monocyte
D009239	N-Formylmethionine	Effective in the initiation of protein synthesis. The initiating methionine residue enters the ribosome as N-formylmethionyl tRNA. This process occurs in Escherichia coli and other bacteria as well as in the mitochondria of eucaryotic cells.	N Formylmethionine,Formylmethionine, N
D009240	N-Formylmethionine Leucyl-Phenylalanine	A formylated tripeptide originally isolated from bacterial filtrates that is positively chemotactic to polymorphonuclear leucocytes, and causes them to release lysosomal enzymes and become metabolically activated.	F-Met-Leu-Phe,N-Formyl-Methionyl-Leucyl-Phenylalanine,Formylmet-Leu-Phe,Formylmethionyl Peptide,Formylmethionyl-Leucyl-Phenylalanine,Formylmethionylleucylphenylalanine,N-Formylated Peptide,N-formylmethionyl-leucyl-phenylalanine,fMet-Leu-Phe,F Met Leu Phe,Formylmet Leu Phe,Formylmethionyl Leucyl Phenylalanine,Leucyl-Phenylalanine, N-Formylmethionine,N Formyl Methionyl Leucyl Phenylalanine,N Formylated Peptide,N Formylmethionine Leucyl Phenylalanine,N formylmethionyl leucyl phenylalanine,Peptide, Formylmethionyl,Peptide, N-Formylated,fMet Leu Phe
D009842	Oligopeptides	Peptides composed of between two and twelve amino acids.	Oligopeptide
D010587	Phagocytosis	The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).	Phagocytoses
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D003571	Cytochalasin B	A cytotoxic member of the CYTOCHALASINS.	Phomin
D006596	Hexosaminidases	Enzymes that catalyze the hydrolysis of N-acylhexosamine residues in N-acylhexosamides. Hexosaminidases also act on GLUCOSIDES; GALACTOSIDES; and several OLIGOSACCHARIDES.	Galactosaminidases,Hexosaminidase,Galactosaminidase,Glucosaminidase,Glucosaminidases