title: Optimedin induces expression of N-cadherin and stimulates aggregation of NGF-stimulated PC12 cells.
abstract: Optimedin, also known as olfactomedin 3, belongs to a family of olfactomedin domain-containing proteins. It is expressed in neural tissues and Pax6 is involved in the regulation of its promoter. To study possible effects of optimedin on the differentiation of neural cells, we produced stably transfected PC12 cell lines expressing optimedin under a tetracycline-inducible promoter. Cells expressing high levels of optimedin showed higher growth rates and stronger adhesion to the collagen extracellular matrix as compared with control PC12 cells. After stimulation with nerve growth factor (NGF), optimedin-expressing cells demonstrated elevated levels of N-cadherin, beta-catenin, alpha-catenin and occludin as compared with stimulated, control PC12 cells. Expression of optimedin induced Ca(2+)-dependent aggregation of NGF-stimulated PC12 cells and this aggregation was blocked by the expression of N-cadherin siRNA. Expression of optimedin also changed the organization of the actin cytoskeleton and inhibited neurite outgrowth in NGF-stimulated PC12 cells. We suggest that expression of optimedin stimulates the formation of adherent and tight junctions on the cell surface and this may play an important role in the differentiation of the brain and retina through the modulation of cytoskeleton organization, cell-cell adhesion and migration.
authors.affiliation: Section of Molecular Mechanisms of Glaucoma, Laboratory of Molecular and Developmental Biology, National Eye Institute, NIH, Bldg. 7, Room 103, MSC 0704, Bethesda, MD 20892-0704, USA.
authors.forename: Hee-Sheung
authors.initials: HS
authors.lastname: Lee
authors.forename: Stanislav I
authors.initials: SI
authors.lastname: Tomarev
mesh_terms: D000818:Animals; D001483:Base Sequence; D015820:Cadherins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002449:Cell Aggregation / Q000187:drug effects; D017931:DNA Primers / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D020932:Nerve Growth Factor / Q000494:pharmacology*; D016501:Neurites / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D016716:PC12 Cells; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection; D051178:alpha Catenin / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
chemical_list: D015820:Cadherins; D017931:DNA Primers; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; C466063:Olfm3 protein, rat; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D051178:alpha Catenin; D051176:beta Catenin; D020932:Nerve Growth Factor