title: Differential expression of nitric oxide synthases in EGF-responsive mouse neural precursor cells.
abstract: Nitric oxide (NO) is a gaseous, radical molecule that plays a role in various physiological processes in the nervous system such as learning and hippocampal plasticity. It is generated from l-arginine by nitric oxide synthases (NOS), which come in three isoforms depending on the tissue of origin, namely inducible-NOS (iNOS in macrophages), endothelial-NOS (eNOS in endothelial cells) and neural-NOS (nNOS in neural cells). We used epidermal growth factor (EGF)-responsive nestin-positive neural precursor cells originating from the mouse E16 embryonic striatum, and studied the relative expression of NOS isoforms probed with isoform-specific antibody using the avidin-biotin immunohistochemical method. Our data revealed both nNOS and eNOS to be expressed in both neurospheres and desegregated neural precursor cells. However, iNOS signals were virtually undetectable in both cell categories. When the neural precursor cells were carried in the presence of poly-l-ornithine (PLO), there was a strong induction of the expression of iNOS proteins, indicating the possibility that this isoform is amenable to modulation by extracellular cues. These preliminary results suggest both nNOS and eNOS to be important in the physiology of neural precursor cells, and that iNOS might also play a role at certain stages in the life of these cells.
authors.affiliation: Division of Radiation Oncology, Cancer Center, The University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA. tao.wang@ummed.edu
authors.forename: T
authors.initials: T
authors.lastname: Wang
authors.forename: T J
authors.initials: TJ
authors.lastname: FitzGerald
authors.forename: A
authors.initials: A
authors.lastname: Haregewoin
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D009474:Neurons / Q000166:cytology*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D013234:Stem Cells / Q000166:cytology* / Q000201:enzymology*
chemical_list: D007527:Isoenzymes; D009419:Nerve Tissue Proteins; D004815:Epidermal Growth Factor; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496321:Nos1 protein, mouse; C496317:Nos2 protein, mouse; C496315:Nos3 protein, mouse